leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
87f0e46e75
linux/arch/s390/mm/kasan_init.c

428 lines
12 KiB
C
Raw Normal View History

s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
// SPDX-License-Identifier: GPL-2.0
#include <linux/kasan.h>
#include <linux/sched/task.h>
#include <linux/memblock.h>
mm: introduce include/linux/pgtable.h The include/linux/pgtable.h is going to be the home of generic page table manipulation functions. Start with moving asm-generic/pgtable.h to include/linux/pgtable.h and make the latter include asm/pgtable.h. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-3-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 04:32:38 +00:00
#include <linux/pgtable.h>
mm: reorder includes after introduction of linux/pgtable.h The replacement of <asm/pgrable.h> with <linux/pgtable.h> made the include of the latter in the middle of asm includes. Fix this up with the aid of the below script and manual adjustments here and there. import sys import re if len(sys.argv) is not 3: print "USAGE: %s <file> <header>" % (sys.argv[0]) sys.exit(1) hdr_to_move="#include <linux/%s>" % sys.argv[2] moved = False in_hdrs = False with open(sys.argv[1], "r") as f: lines = f.readlines() for _line in lines: line = _line.rstrip(' ') if line == hdr_to_move: continue if line.startswith("#include <linux/"): in_hdrs = True elif not moved and in_hdrs: moved = True print hdr_to_move print line Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Cain <bcain@codeaurora.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Ley Foon Tan <ley.foon.tan@intel.com> Cc: Mark Salter <msalter@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Link: http://lkml.kernel.org/r/20200514170327.31389-4-rppt@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-06-09 04:32:42 +00:00
#include <asm/pgalloc.h>
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
#include <asm/kasan.h>
s390/kasan: avoid kasan crash with standby memory defined Kasan early memory allocator simply chops off memory blocks from the end of the physical memory. Reuse mem_detect info to identify actual online memory end rather than using max_physmem_end. This allows to run the kernel with kasan enabled and standby memory defined. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-09-13 08:59:25 +00:00
#include <asm/mem_detect.h>
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
#include <asm/processor.h>
#include <asm/sclp.h>
s390/kasan: use noexec and large pages To lower memory footprint and speed up kasan initialisation detect EDAT availability and use large pages if possible. As we know how much memory is needed for initialisation, another simplistic large page allocator is introduced to avoid memory fragmentation. Since facilities list is retrieved anyhow, detect noexec support and adjust pages attributes. Handle noexec kernel option to avoid inconsistent kasan shadow memory pages flags. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:44:28 +00:00
#include <asm/facility.h>
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
#include <asm/sections.h>
#include <asm/setup.h>
s390/kasan: support protvirt with 4-level paging Currently the kernel crashes in Kasan instrumentation code if CONFIG_KASAN_S390_4_LEVEL_PAGING is used on protected virtualization capable machine where the ultravisor imposes addressing limitations on the host and those limitations are lower then KASAN_SHADOW_OFFSET. The problem is that Kasan has to know in advance where vmalloc/modules areas would be. With protected virtualization enabled vmalloc/modules areas are moved down to the ultravisor secure storage limit while kasan still expects them at the very end of 4-level paging address space. To fix that make Kasan recognize when protected virtualization is enabled and predefine vmalloc/modules areas position which are compliant with ultravisor secure storage limit. Kasan shadow itself stays in place and might reside above that ultravisor secure storage limit. One slight difference compaired to a kernel without Kasan enabled is that vmalloc/modules areas position is not reverted to default if ultravisor initialization fails. It would still be below the ultravisor secure storage limit. Kernel layout with kasan, 4-level paging and protected virtualization enabled (ultravisor secure storage limit is at 0x0000800000000000): ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400080000000 ---[ vmemmap Area End ]--- ---[ vmalloc Area Start ]--- 0x00007fe000000000-0x00007fff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x00007fff80000000-0x0000800000000000 ---[ Modules Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- 0x001c000000000000-0x0020000000000000 1P PGD I Kernel layout with kasan, 4-level paging and protected virtualization disabled/unsupported: ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400060000000 ---[ vmemmap Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- ---[ vmalloc Area Start ]--- 0x001fffe000000000-0x001fffff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x001fffff80000000-0x0020000000000000 ---[ Modules Area End ]--- Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-11 09:44:47 +00:00
#include <asm/uv.h>
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
s390/kasan: support protvirt with 4-level paging Currently the kernel crashes in Kasan instrumentation code if CONFIG_KASAN_S390_4_LEVEL_PAGING is used on protected virtualization capable machine where the ultravisor imposes addressing limitations on the host and those limitations are lower then KASAN_SHADOW_OFFSET. The problem is that Kasan has to know in advance where vmalloc/modules areas would be. With protected virtualization enabled vmalloc/modules areas are moved down to the ultravisor secure storage limit while kasan still expects them at the very end of 4-level paging address space. To fix that make Kasan recognize when protected virtualization is enabled and predefine vmalloc/modules areas position which are compliant with ultravisor secure storage limit. Kasan shadow itself stays in place and might reside above that ultravisor secure storage limit. One slight difference compaired to a kernel without Kasan enabled is that vmalloc/modules areas position is not reverted to default if ultravisor initialization fails. It would still be below the ultravisor secure storage limit. Kernel layout with kasan, 4-level paging and protected virtualization enabled (ultravisor secure storage limit is at 0x0000800000000000): ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400080000000 ---[ vmemmap Area End ]--- ---[ vmalloc Area Start ]--- 0x00007fe000000000-0x00007fff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x00007fff80000000-0x0000800000000000 ---[ Modules Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- 0x001c000000000000-0x0020000000000000 1P PGD I Kernel layout with kasan, 4-level paging and protected virtualization disabled/unsupported: ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400060000000 ---[ vmemmap Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- ---[ vmalloc Area Start ]--- 0x001fffe000000000-0x001fffff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x001fffff80000000-0x0020000000000000 ---[ Modules Area End ]--- Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-11 09:44:47 +00:00
unsigned long kasan_vmax;
s390/kasan: use noexec and large pages To lower memory footprint and speed up kasan initialisation detect EDAT availability and use large pages if possible. As we know how much memory is needed for initialisation, another simplistic large page allocator is introduced to avoid memory fragmentation. Since facilities list is retrieved anyhow, detect noexec support and adjust pages attributes. Handle noexec kernel option to avoid inconsistent kasan shadow memory pages flags. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:44:28 +00:00
static unsigned long segment_pos __initdata;
static unsigned long segment_low __initdata;
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
static unsigned long pgalloc_pos __initdata;
static unsigned long pgalloc_low __initdata;
s390/kasan: free early identity mapping structures Kasan initialization code is changed to populate persistent shadow first, save allocator position into pgalloc_freeable and proceed with early identity mapping creation. This way early identity mapping paging structures could be freed at once after switching to swapper_pg_dir when early identity mapping is not needed anymore. Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-20 11:56:10 +00:00
static unsigned long pgalloc_freeable __initdata;
s390/kasan: use noexec and large pages To lower memory footprint and speed up kasan initialisation detect EDAT availability and use large pages if possible. As we know how much memory is needed for initialisation, another simplistic large page allocator is introduced to avoid memory fragmentation. Since facilities list is retrieved anyhow, detect noexec support and adjust pages attributes. Handle noexec kernel option to avoid inconsistent kasan shadow memory pages flags. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:44:28 +00:00
static bool has_edat __initdata;
static bool has_nx __initdata;
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
#define __sha(x) ((unsigned long)kasan_mem_to_shadow((void *)x))
static pgd_t early_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE);
static void __init kasan_early_panic(const char *reason)
{
sclp_early_printk("The Linux kernel failed to boot with the KernelAddressSanitizer:\n");
sclp_early_printk(reason);
s390/kasan: adapt disabled_wait usage to avoid build error Fix the following build error when the kernel is built with CONFIG_KASAN broken since commit 98587c2d894c ("s390: simplify disabled_wait"): arch/s390/mm/kasan_init.c: In function 'kasan_early_panic': arch/s390/mm/kasan_init.c:31:2: error: too many arguments to function 'disabled_wait' 31 | disabled_wait(0); Fixes: 98587c2d894c ("s390: simplify disabled_wait") Reported-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2019-05-08 11:36:06 +00:00
disabled_wait();
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
}
s390/kasan: use noexec and large pages To lower memory footprint and speed up kasan initialisation detect EDAT availability and use large pages if possible. As we know how much memory is needed for initialisation, another simplistic large page allocator is introduced to avoid memory fragmentation. Since facilities list is retrieved anyhow, detect noexec support and adjust pages attributes. Handle noexec kernel option to avoid inconsistent kasan shadow memory pages flags. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:44:28 +00:00
static void * __init kasan_early_alloc_segment(void)
{
segment_pos -= _SEGMENT_SIZE;
if (segment_pos < segment_low)
kasan_early_panic("out of memory during initialisation\n");
return (void *)segment_pos;
}
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
static void * __init kasan_early_alloc_pages(unsigned int order)
{
pgalloc_pos -= (PAGE_SIZE << order);
if (pgalloc_pos < pgalloc_low)
kasan_early_panic("out of memory during initialisation\n");
return (void *)pgalloc_pos;
}
static void * __init kasan_early_crst_alloc(unsigned long val)
{
unsigned long *table;
table = kasan_early_alloc_pages(CRST_ALLOC_ORDER);
if (table)
crst_table_init(table, val);
return table;
}
static pte_t * __init kasan_early_pte_alloc(void)
{
static void *pte_leftover;
pte_t *pte;
BUILD_BUG_ON(_PAGE_TABLE_SIZE * 2 != PAGE_SIZE);
if (!pte_leftover) {
pte_leftover = kasan_early_alloc_pages(0);
pte = pte_leftover + _PAGE_TABLE_SIZE;
} else {
pte = pte_leftover;
pte_leftover = NULL;
}
memset64((u64 *)pte, _PAGE_INVALID, PTRS_PER_PTE);
return pte;
}
enum populate_mode {
POPULATE_ONE2ONE,
POPULATE_MAP,
s390/kasan: add KASAN_VMALLOC support Add KASAN_VMALLOC support which now enables vmalloc memory area access checks as well as enables usage of VMAP_STACK under kasan. KASAN_VMALLOC changes the way vmalloc and modules areas shadow memory is handled. With this new approach only top level page tables are pre-populated and lower levels are filled dynamically upon memory allocation. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-02 10:42:59 +00:00
POPULATE_ZERO_SHADOW,
POPULATE_SHALLOW
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
};
s390/kasan: avoid confusing naming Kasan has nothing to do with vmemmap, strip vmemmap from function names to avoid confusing people. Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-05 07:13:15 +00:00
static void __init kasan_early_pgtable_populate(unsigned long address,
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
unsigned long end,
enum populate_mode mode)
{
s390/kasan: use noexec and large pages To lower memory footprint and speed up kasan initialisation detect EDAT availability and use large pages if possible. As we know how much memory is needed for initialisation, another simplistic large page allocator is introduced to avoid memory fragmentation. Since facilities list is retrieved anyhow, detect noexec support and adjust pages attributes. Handle noexec kernel option to avoid inconsistent kasan shadow memory pages flags. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:44:28 +00:00
unsigned long pgt_prot_zero, pgt_prot, sgt_prot;
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
pgd_t *pg_dir;
p4d_t *p4_dir;
pud_t *pu_dir;
pmd_t *pm_dir;
pte_t *pt_dir;
pgt_prot_zero = pgprot_val(PAGE_KERNEL_RO);
s390/kasan: use noexec and large pages To lower memory footprint and speed up kasan initialisation detect EDAT availability and use large pages if possible. As we know how much memory is needed for initialisation, another simplistic large page allocator is introduced to avoid memory fragmentation. Since facilities list is retrieved anyhow, detect noexec support and adjust pages attributes. Handle noexec kernel option to avoid inconsistent kasan shadow memory pages flags. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:44:28 +00:00
if (!has_nx)
pgt_prot_zero &= ~_PAGE_NOEXEC;
s390/kasan: make shadow memory noexec ARCH_HAS_DEBUG_WX feature support brought attention to the fact that currently initial kasan shadow memory mapped without noexec flag. So fix that. Temporary initial identity mapping is still created without noexec, but it is replaced by properly set up paging later. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-10 20:25:13 +00:00
pgt_prot = pgprot_val(PAGE_KERNEL);
sgt_prot = pgprot_val(SEGMENT_KERNEL);
if (!has_nx || mode == POPULATE_ONE2ONE) {
pgt_prot &= ~_PAGE_NOEXEC;
sgt_prot &= ~_SEGMENT_ENTRY_NOEXEC;
}
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
while (address < end) {
pg_dir = pgd_offset_k(address);
if (pgd_none(*pg_dir)) {
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, PGDIR_SIZE) &&
end - address >= PGDIR_SIZE) {
kasan: rename kasan_zero_page to kasan_early_shadow_page With tag based KASAN mode the early shadow value is 0xff and not 0x00, so this patch renames kasan_zero_(page|pte|pmd|pud|p4d) to kasan_early_shadow_(page|pte|pmd|pud|p4d) to avoid confusion. Link: http://lkml.kernel.org/r/3fed313280ebf4f88645f5b89ccbc066d320e177.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 08:30:01 +00:00
pgd_populate(&init_mm, pg_dir,
kasan_early_shadow_p4d);
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
address = (address + PGDIR_SIZE) & PGDIR_MASK;
continue;
}
p4_dir = kasan_early_crst_alloc(_REGION2_ENTRY_EMPTY);
pgd_populate(&init_mm, pg_dir, p4_dir);
}
s390/kasan: remove 3-level paging support Compiling the kernel with Kasan disables automatic 3-level vs 4-level kernel space paging selection, because the shadow memory offset has to be known at compile time and there is no such offset which would be acceptable for both 3 and 4-level paging. Instead S390_4_LEVEL_PAGING option was introduced which allowed to pick how many paging levels to use under Kasan. With the introduction of protected virtualization, kernel memory layout may be affected due to ultravisor secure storage limit. This adds additional complexity into how memory layout would look like in combination with Kasan predefined shadow memory offsets. To simplify this make Kasan 4-level paging default and remove Kasan 3-level paging support. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-15 08:01:42 +00:00
if (mode == POPULATE_SHALLOW) {
s390/kasan: add KASAN_VMALLOC support Add KASAN_VMALLOC support which now enables vmalloc memory area access checks as well as enables usage of VMAP_STACK under kasan. KASAN_VMALLOC changes the way vmalloc and modules areas shadow memory is handled. With this new approach only top level page tables are pre-populated and lower levels are filled dynamically upon memory allocation. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-02 10:42:59 +00:00
address = (address + P4D_SIZE) & P4D_MASK;
continue;
}
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
p4_dir = p4d_offset(pg_dir, address);
if (p4d_none(*p4_dir)) {
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, P4D_SIZE) &&
end - address >= P4D_SIZE) {
kasan: rename kasan_zero_page to kasan_early_shadow_page With tag based KASAN mode the early shadow value is 0xff and not 0x00, so this patch renames kasan_zero_(page|pte|pmd|pud|p4d) to kasan_early_shadow_(page|pte|pmd|pud|p4d) to avoid confusion. Link: http://lkml.kernel.org/r/3fed313280ebf4f88645f5b89ccbc066d320e177.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 08:30:01 +00:00
p4d_populate(&init_mm, p4_dir,
kasan_early_shadow_pud);
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
address = (address + P4D_SIZE) & P4D_MASK;
continue;
}
pu_dir = kasan_early_crst_alloc(_REGION3_ENTRY_EMPTY);
p4d_populate(&init_mm, p4_dir, pu_dir);
}
pu_dir = pud_offset(p4_dir, address);
if (pud_none(*pu_dir)) {
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, PUD_SIZE) &&
end - address >= PUD_SIZE) {
kasan: rename kasan_zero_page to kasan_early_shadow_page With tag based KASAN mode the early shadow value is 0xff and not 0x00, so this patch renames kasan_zero_(page|pte|pmd|pud|p4d) to kasan_early_shadow_(page|pte|pmd|pud|p4d) to avoid confusion. Link: http://lkml.kernel.org/r/3fed313280ebf4f88645f5b89ccbc066d320e177.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 08:30:01 +00:00
pud_populate(&init_mm, pu_dir,
kasan_early_shadow_pmd);
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
address = (address + PUD_SIZE) & PUD_MASK;
continue;
}
pm_dir = kasan_early_crst_alloc(_SEGMENT_ENTRY_EMPTY);
pud_populate(&init_mm, pu_dir, pm_dir);
}
pm_dir = pmd_offset(pu_dir, address);
if (pmd_none(*pm_dir)) {
if (mode == POPULATE_ZERO_SHADOW &&
IS_ALIGNED(address, PMD_SIZE) &&
end - address >= PMD_SIZE) {
kasan: rename kasan_zero_page to kasan_early_shadow_page With tag based KASAN mode the early shadow value is 0xff and not 0x00, so this patch renames kasan_zero_(page|pte|pmd|pud|p4d) to kasan_early_shadow_(page|pte|pmd|pud|p4d) to avoid confusion. Link: http://lkml.kernel.org/r/3fed313280ebf4f88645f5b89ccbc066d320e177.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 08:30:01 +00:00
pmd_populate(&init_mm, pm_dir,
kasan_early_shadow_pte);
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
address = (address + PMD_SIZE) & PMD_MASK;
continue;
}
s390/kasan: use noexec and large pages To lower memory footprint and speed up kasan initialisation detect EDAT availability and use large pages if possible. As we know how much memory is needed for initialisation, another simplistic large page allocator is introduced to avoid memory fragmentation. Since facilities list is retrieved anyhow, detect noexec support and adjust pages attributes. Handle noexec kernel option to avoid inconsistent kasan shadow memory pages flags. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:44:28 +00:00
/* the first megabyte of 1:1 is mapped with 4k pages */
if (has_edat && address && end - address >= PMD_SIZE &&
mode != POPULATE_ZERO_SHADOW) {
void *page;
if (mode == POPULATE_ONE2ONE) {
page = (void *)address;
} else {
page = kasan_early_alloc_segment();
memset(page, 0, _SEGMENT_SIZE);
}
pmd_val(*pm_dir) = __pa(page) | sgt_prot;
address = (address + PMD_SIZE) & PMD_MASK;
continue;
}
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
pt_dir = kasan_early_pte_alloc();
pmd_populate(&init_mm, pm_dir, pt_dir);
s390/kasan: use noexec and large pages To lower memory footprint and speed up kasan initialisation detect EDAT availability and use large pages if possible. As we know how much memory is needed for initialisation, another simplistic large page allocator is introduced to avoid memory fragmentation. Since facilities list is retrieved anyhow, detect noexec support and adjust pages attributes. Handle noexec kernel option to avoid inconsistent kasan shadow memory pages flags. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:44:28 +00:00
} else if (pmd_large(*pm_dir)) {
address = (address + PMD_SIZE) & PMD_MASK;
continue;
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
}
pt_dir = pte_offset_kernel(pm_dir, address);
if (pte_none(*pt_dir)) {
void *page;
switch (mode) {
case POPULATE_ONE2ONE:
page = (void *)address;
pte_val(*pt_dir) = __pa(page) | pgt_prot;
break;
case POPULATE_MAP:
page = kasan_early_alloc_pages(0);
memset(page, 0, PAGE_SIZE);
pte_val(*pt_dir) = __pa(page) | pgt_prot;
break;
case POPULATE_ZERO_SHADOW:
kasan: rename kasan_zero_page to kasan_early_shadow_page With tag based KASAN mode the early shadow value is 0xff and not 0x00, so this patch renames kasan_zero_(page|pte|pmd|pud|p4d) to kasan_early_shadow_(page|pte|pmd|pud|p4d) to avoid confusion. Link: http://lkml.kernel.org/r/3fed313280ebf4f88645f5b89ccbc066d320e177.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 08:30:01 +00:00
page = kasan_early_shadow_page;
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
pte_val(*pt_dir) = __pa(page) | pgt_prot_zero;
break;
s390/kasan: add KASAN_VMALLOC support Add KASAN_VMALLOC support which now enables vmalloc memory area access checks as well as enables usage of VMAP_STACK under kasan. KASAN_VMALLOC changes the way vmalloc and modules areas shadow memory is handled. With this new approach only top level page tables are pre-populated and lower levels are filled dynamically upon memory allocation. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-02 10:42:59 +00:00
case POPULATE_SHALLOW:
/* should never happen */
break;
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
}
}
address += PAGE_SIZE;
}
}
static void __init kasan_set_pgd(pgd_t *pgd, unsigned long asce_type)
{
unsigned long asce_bits;
asce_bits = asce_type | _ASCE_TABLE_LENGTH;
S390_lowcore.kernel_asce = (__pa(pgd) & PAGE_MASK) | asce_bits;
S390_lowcore.user_asce = S390_lowcore.kernel_asce;
__ctl_load(S390_lowcore.kernel_asce, 1, 1);
__ctl_load(S390_lowcore.kernel_asce, 7, 7);
__ctl_load(S390_lowcore.kernel_asce, 13, 13);
}
static void __init kasan_enable_dat(void)
{
psw_t psw;
psw.mask = __extract_psw();
psw_bits(psw).dat = 1;
psw_bits(psw).as = PSW_BITS_AS_HOME;
__load_psw_mask(psw.mask);
}
s390/kasan: use noexec and large pages To lower memory footprint and speed up kasan initialisation detect EDAT availability and use large pages if possible. As we know how much memory is needed for initialisation, another simplistic large page allocator is introduced to avoid memory fragmentation. Since facilities list is retrieved anyhow, detect noexec support and adjust pages attributes. Handle noexec kernel option to avoid inconsistent kasan shadow memory pages flags. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:44:28 +00:00
static void __init kasan_early_detect_facilities(void)
{
if (test_facility(8)) {
has_edat = true;
__ctl_set_bit(0, 23);
}
if (!noexec_disabled && test_facility(130)) {
has_nx = true;
__ctl_set_bit(0, 20);
}
}
s390/kasan: support protvirt with 4-level paging Currently the kernel crashes in Kasan instrumentation code if CONFIG_KASAN_S390_4_LEVEL_PAGING is used on protected virtualization capable machine where the ultravisor imposes addressing limitations on the host and those limitations are lower then KASAN_SHADOW_OFFSET. The problem is that Kasan has to know in advance where vmalloc/modules areas would be. With protected virtualization enabled vmalloc/modules areas are moved down to the ultravisor secure storage limit while kasan still expects them at the very end of 4-level paging address space. To fix that make Kasan recognize when protected virtualization is enabled and predefine vmalloc/modules areas position which are compliant with ultravisor secure storage limit. Kasan shadow itself stays in place and might reside above that ultravisor secure storage limit. One slight difference compaired to a kernel without Kasan enabled is that vmalloc/modules areas position is not reverted to default if ultravisor initialization fails. It would still be below the ultravisor secure storage limit. Kernel layout with kasan, 4-level paging and protected virtualization enabled (ultravisor secure storage limit is at 0x0000800000000000): ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400080000000 ---[ vmemmap Area End ]--- ---[ vmalloc Area Start ]--- 0x00007fe000000000-0x00007fff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x00007fff80000000-0x0000800000000000 ---[ Modules Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- 0x001c000000000000-0x0020000000000000 1P PGD I Kernel layout with kasan, 4-level paging and protected virtualization disabled/unsupported: ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400060000000 ---[ vmemmap Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- ---[ vmalloc Area Start ]--- 0x001fffe000000000-0x001fffff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x001fffff80000000-0x0020000000000000 ---[ Modules Area End ]--- Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-11 09:44:47 +00:00
static bool __init has_uv_sec_stor_limit(void)
{
/*
* keep these conditions in line with setup_uv()
*/
if (!is_prot_virt_host())
return false;
if (is_prot_virt_guest())
return false;
if (!test_facility(158))
return false;
return !!uv_info.max_sec_stor_addr;
}
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
void __init kasan_early_init(void)
{
unsigned long untracked_mem_end;
unsigned long shadow_alloc_size;
s390/kasan: support protvirt with 4-level paging Currently the kernel crashes in Kasan instrumentation code if CONFIG_KASAN_S390_4_LEVEL_PAGING is used on protected virtualization capable machine where the ultravisor imposes addressing limitations on the host and those limitations are lower then KASAN_SHADOW_OFFSET. The problem is that Kasan has to know in advance where vmalloc/modules areas would be. With protected virtualization enabled vmalloc/modules areas are moved down to the ultravisor secure storage limit while kasan still expects them at the very end of 4-level paging address space. To fix that make Kasan recognize when protected virtualization is enabled and predefine vmalloc/modules areas position which are compliant with ultravisor secure storage limit. Kasan shadow itself stays in place and might reside above that ultravisor secure storage limit. One slight difference compaired to a kernel without Kasan enabled is that vmalloc/modules areas position is not reverted to default if ultravisor initialization fails. It would still be below the ultravisor secure storage limit. Kernel layout with kasan, 4-level paging and protected virtualization enabled (ultravisor secure storage limit is at 0x0000800000000000): ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400080000000 ---[ vmemmap Area End ]--- ---[ vmalloc Area Start ]--- 0x00007fe000000000-0x00007fff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x00007fff80000000-0x0000800000000000 ---[ Modules Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- 0x001c000000000000-0x0020000000000000 1P PGD I Kernel layout with kasan, 4-level paging and protected virtualization disabled/unsupported: ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400060000000 ---[ vmemmap Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- ---[ vmalloc Area Start ]--- 0x001fffe000000000-0x001fffff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x001fffff80000000-0x0020000000000000 ---[ Modules Area End ]--- Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-11 09:44:47 +00:00
unsigned long vmax_unlimited;
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
unsigned long initrd_end;
unsigned long memsize;
unsigned long pgt_prot = pgprot_val(PAGE_KERNEL_RO);
pte_t pte_z;
kasan: rename kasan_zero_page to kasan_early_shadow_page With tag based KASAN mode the early shadow value is 0xff and not 0x00, so this patch renames kasan_zero_(page|pte|pmd|pud|p4d) to kasan_early_shadow_(page|pte|pmd|pud|p4d) to avoid confusion. Link: http://lkml.kernel.org/r/3fed313280ebf4f88645f5b89ccbc066d320e177.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 08:30:01 +00:00
pmd_t pmd_z = __pmd(__pa(kasan_early_shadow_pte) | _SEGMENT_ENTRY);
pud_t pud_z = __pud(__pa(kasan_early_shadow_pmd) | _REGION3_ENTRY);
p4d_t p4d_z = __p4d(__pa(kasan_early_shadow_pud) | _REGION2_ENTRY);
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
s390/kasan: use noexec and large pages To lower memory footprint and speed up kasan initialisation detect EDAT availability and use large pages if possible. As we know how much memory is needed for initialisation, another simplistic large page allocator is introduced to avoid memory fragmentation. Since facilities list is retrieved anyhow, detect noexec support and adjust pages attributes. Handle noexec kernel option to avoid inconsistent kasan shadow memory pages flags. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:44:28 +00:00
kasan_early_detect_facilities();
if (!has_nx)
pgt_prot &= ~_PAGE_NOEXEC;
kasan: rename kasan_zero_page to kasan_early_shadow_page With tag based KASAN mode the early shadow value is 0xff and not 0x00, so this patch renames kasan_zero_(page|pte|pmd|pud|p4d) to kasan_early_shadow_(page|pte|pmd|pud|p4d) to avoid confusion. Link: http://lkml.kernel.org/r/3fed313280ebf4f88645f5b89ccbc066d320e177.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 08:30:01 +00:00
pte_z = __pte(__pa(kasan_early_shadow_page) | pgt_prot);
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
s390/kasan: avoid kasan crash with standby memory defined Kasan early memory allocator simply chops off memory blocks from the end of the physical memory. Reuse mem_detect info to identify actual online memory end rather than using max_physmem_end. This allows to run the kernel with kasan enabled and standby memory defined. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-09-13 08:59:25 +00:00
memsize = get_mem_detect_end();
if (!memsize)
kasan_early_panic("cannot detect physical memory size\n");
s390: unify identity mapping limits handling Currently we have to consider too many different values which in the end only affect identity mapping size. These are: 1. max_physmem_end - end of physical memory online or standby. Always <= end of the last online memory block (get_mem_detect_end()). 2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the kernel is able to support. 3. "mem=" kernel command line option which limits physical memory usage. 4. OLDMEM_BASE which is a kdump memory limit when the kernel is executed as crash kernel. 5. "hsa" size which is a memory limit when the kernel is executed during zfcp/nvme dump. Through out kernel startup and run we juggle all those values at once but that does not bring any amusement, only confusion and complexity. Unify all those values to a single one we should really care, that is our identity mapping size. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-19 09:01:33 +00:00
/*
* Kasan currently supports standby memory but only if it follows
* online memory (default allocation), i.e. no memory holes.
* - memsize represents end of online memory
* - ident_map_size represents online + standby and memory limits
* accounted.
* Kasan maps "memsize" right away.
* [0, memsize] - as identity mapping
* [__sha(0), __sha(memsize)] - shadow memory for identity mapping
* The rest [memsize, ident_map_size] if memsize < ident_map_size
* could be mapped/unmapped dynamically later during memory hotplug.
*/
memsize = min(memsize, ident_map_size);
s390/kasan: avoid kasan crash with standby memory defined Kasan early memory allocator simply chops off memory blocks from the end of the physical memory. Reuse mem_detect info to identify actual online memory end rather than using max_physmem_end. This allows to run the kernel with kasan enabled and standby memory defined. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2018-09-13 08:59:25 +00:00
s390/kasan: remove 3-level paging support Compiling the kernel with Kasan disables automatic 3-level vs 4-level kernel space paging selection, because the shadow memory offset has to be known at compile time and there is no such offset which would be acceptable for both 3 and 4-level paging. Instead S390_4_LEVEL_PAGING option was introduced which allowed to pick how many paging levels to use under Kasan. With the introduction of protected virtualization, kernel memory layout may be affected due to ultravisor secure storage limit. This adds additional complexity into how memory layout would look like in combination with Kasan predefined shadow memory offsets. To simplify this make Kasan 4-level paging default and remove Kasan 3-level paging support. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-15 08:01:42 +00:00
BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, P4D_SIZE));
BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, P4D_SIZE));
crst_table_init((unsigned long *)early_pg_dir, _REGION2_ENTRY_EMPTY);
untracked_mem_end = kasan_vmax = vmax_unlimited = _REGION1_SIZE;
if (has_uv_sec_stor_limit())
kasan_vmax = min(vmax_unlimited, uv_info.max_sec_stor_addr);
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
/* init kasan zero shadow */
kasan: rename kasan_zero_page to kasan_early_shadow_page With tag based KASAN mode the early shadow value is 0xff and not 0x00, so this patch renames kasan_zero_(page|pte|pmd|pud|p4d) to kasan_early_shadow_(page|pte|pmd|pud|p4d) to avoid confusion. Link: http://lkml.kernel.org/r/3fed313280ebf4f88645f5b89ccbc066d320e177.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Suggested-by: Mark Rutland <mark.rutland@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 08:30:01 +00:00
crst_table_init((unsigned long *)kasan_early_shadow_p4d,
p4d_val(p4d_z));
crst_table_init((unsigned long *)kasan_early_shadow_pud,
pud_val(pud_z));
crst_table_init((unsigned long *)kasan_early_shadow_pmd,
pmd_val(pmd_z));
memset64((u64 *)kasan_early_shadow_pte, pte_val(pte_z), PTRS_PER_PTE);
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
shadow_alloc_size = memsize >> KASAN_SHADOW_SCALE_SHIFT;
pgalloc_low = round_up((unsigned long)_end, _SEGMENT_SIZE);
if (IS_ENABLED(CONFIG_BLK_DEV_INITRD)) {
initrd_end =
round_up(INITRD_START + INITRD_SIZE, _SEGMENT_SIZE);
pgalloc_low = max(pgalloc_low, initrd_end);
}
if (pgalloc_low + shadow_alloc_size > memsize)
kasan_early_panic("out of memory during initialisation\n");
s390/kasan: use noexec and large pages To lower memory footprint and speed up kasan initialisation detect EDAT availability and use large pages if possible. As we know how much memory is needed for initialisation, another simplistic large page allocator is introduced to avoid memory fragmentation. Since facilities list is retrieved anyhow, detect noexec support and adjust pages attributes. Handle noexec kernel option to avoid inconsistent kasan shadow memory pages flags. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:44:28 +00:00
if (has_edat) {
segment_pos = round_down(memsize, _SEGMENT_SIZE);
segment_low = segment_pos - shadow_alloc_size;
pgalloc_pos = segment_low;
} else {
pgalloc_pos = memsize;
}
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
init_mm.pgd = early_pg_dir;
/*
* Current memory layout:
s390/kasan: add KASAN_VMALLOC support Add KASAN_VMALLOC support which now enables vmalloc memory area access checks as well as enables usage of VMAP_STACK under kasan. KASAN_VMALLOC changes the way vmalloc and modules areas shadow memory is handled. With this new approach only top level page tables are pre-populated and lower levels are filled dynamically upon memory allocation. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-02 10:42:59 +00:00
* +- 0 -------------+ +- shadow start -+
* | 1:1 ram mapping | /| 1/8 ram |
* | | / | |
* +- end of ram ----+ / +----------------+
* | ... gap ... | / | |
* | |/ | kasan |
* +- shadow start --+ | zero |
* | 1/8 addr space | | page |
* +- shadow end -+ | mapping |
* | ... gap ... |\ | (untracked) |
* +- vmalloc area -+ \ | |
* | vmalloc_size | \ | |
* +- modules vaddr -+ \ +----------------+
* | 2Gb | \| unmapped | allocated per module
* +-----------------+ +- shadow end ---+
*
* Current memory layout (KASAN_VMALLOC):
* +- 0 -------------+ +- shadow start -+
* | 1:1 ram mapping | /| 1/8 ram |
* | | / | |
* +- end of ram ----+ / +----------------+
* | ... gap ... | / | kasan |
* | |/ | zero |
* +- shadow start --+ | page |
* | 1/8 addr space | | mapping |
* +- shadow end -+ | (untracked) |
* | ... gap ... |\ | |
* +- vmalloc area -+ \ +- vmalloc area -+
* | vmalloc_size | \ |shallow populate|
* +- modules vaddr -+ \ +- modules area -+
* | 2Gb | \|shallow populate|
* +-----------------+ +- shadow end ---+
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
*/
s390/kasan: dynamic shadow mem allocation for modules Move from modules area entire shadow memory preallocation to dynamic allocation per module load. This behaivior has been introduced for x86 with bebf56a1b: "This patch also forces module_alloc() to return 8*PAGE_SIZE aligned address making shadow memory handling ( kasan_module_alloc()/kasan_module_free() ) more simple. Such alignment guarantees that each shadow page backing modules address space correspond to only one module_alloc() allocation" Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:22:24 +00:00
/* populate kasan shadow (for identity mapping and zero page mapping) */
s390/kasan: avoid confusing naming Kasan has nothing to do with vmemmap, strip vmemmap from function names to avoid confusing people. Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-05 07:13:15 +00:00
kasan_early_pgtable_populate(__sha(0), __sha(memsize), POPULATE_MAP);
s390/kasan: dynamic shadow mem allocation for modules Move from modules area entire shadow memory preallocation to dynamic allocation per module load. This behaivior has been introduced for x86 with bebf56a1b: "This patch also forces module_alloc() to return 8*PAGE_SIZE aligned address making shadow memory handling ( kasan_module_alloc()/kasan_module_free() ) more simple. Such alignment guarantees that each shadow page backing modules address space correspond to only one module_alloc() allocation" Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 17:22:24 +00:00
if (IS_ENABLED(CONFIG_MODULES))
s390/kasan: support protvirt with 4-level paging Currently the kernel crashes in Kasan instrumentation code if CONFIG_KASAN_S390_4_LEVEL_PAGING is used on protected virtualization capable machine where the ultravisor imposes addressing limitations on the host and those limitations are lower then KASAN_SHADOW_OFFSET. The problem is that Kasan has to know in advance where vmalloc/modules areas would be. With protected virtualization enabled vmalloc/modules areas are moved down to the ultravisor secure storage limit while kasan still expects them at the very end of 4-level paging address space. To fix that make Kasan recognize when protected virtualization is enabled and predefine vmalloc/modules areas position which are compliant with ultravisor secure storage limit. Kasan shadow itself stays in place and might reside above that ultravisor secure storage limit. One slight difference compaired to a kernel without Kasan enabled is that vmalloc/modules areas position is not reverted to default if ultravisor initialization fails. It would still be below the ultravisor secure storage limit. Kernel layout with kasan, 4-level paging and protected virtualization enabled (ultravisor secure storage limit is at 0x0000800000000000): ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400080000000 ---[ vmemmap Area End ]--- ---[ vmalloc Area Start ]--- 0x00007fe000000000-0x00007fff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x00007fff80000000-0x0000800000000000 ---[ Modules Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- 0x001c000000000000-0x0020000000000000 1P PGD I Kernel layout with kasan, 4-level paging and protected virtualization disabled/unsupported: ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400060000000 ---[ vmemmap Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- ---[ vmalloc Area Start ]--- 0x001fffe000000000-0x001fffff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x001fffff80000000-0x0020000000000000 ---[ Modules Area End ]--- Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-11 09:44:47 +00:00
untracked_mem_end = kasan_vmax - MODULES_LEN;
s390/kasan: add KASAN_VMALLOC support Add KASAN_VMALLOC support which now enables vmalloc memory area access checks as well as enables usage of VMAP_STACK under kasan. KASAN_VMALLOC changes the way vmalloc and modules areas shadow memory is handled. With this new approach only top level page tables are pre-populated and lower levels are filled dynamically upon memory allocation. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-02 10:42:59 +00:00
if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
s390/kasan: support protvirt with 4-level paging Currently the kernel crashes in Kasan instrumentation code if CONFIG_KASAN_S390_4_LEVEL_PAGING is used on protected virtualization capable machine where the ultravisor imposes addressing limitations on the host and those limitations are lower then KASAN_SHADOW_OFFSET. The problem is that Kasan has to know in advance where vmalloc/modules areas would be. With protected virtualization enabled vmalloc/modules areas are moved down to the ultravisor secure storage limit while kasan still expects them at the very end of 4-level paging address space. To fix that make Kasan recognize when protected virtualization is enabled and predefine vmalloc/modules areas position which are compliant with ultravisor secure storage limit. Kasan shadow itself stays in place and might reside above that ultravisor secure storage limit. One slight difference compaired to a kernel without Kasan enabled is that vmalloc/modules areas position is not reverted to default if ultravisor initialization fails. It would still be below the ultravisor secure storage limit. Kernel layout with kasan, 4-level paging and protected virtualization enabled (ultravisor secure storage limit is at 0x0000800000000000): ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400080000000 ---[ vmemmap Area End ]--- ---[ vmalloc Area Start ]--- 0x00007fe000000000-0x00007fff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x00007fff80000000-0x0000800000000000 ---[ Modules Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- 0x001c000000000000-0x0020000000000000 1P PGD I Kernel layout with kasan, 4-level paging and protected virtualization disabled/unsupported: ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400060000000 ---[ vmemmap Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- ---[ vmalloc Area Start ]--- 0x001fffe000000000-0x001fffff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x001fffff80000000-0x0020000000000000 ---[ Modules Area End ]--- Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-11 09:44:47 +00:00
untracked_mem_end = kasan_vmax - vmalloc_size - MODULES_LEN;
s390/kasan: add KASAN_VMALLOC support Add KASAN_VMALLOC support which now enables vmalloc memory area access checks as well as enables usage of VMAP_STACK under kasan. KASAN_VMALLOC changes the way vmalloc and modules areas shadow memory is handled. With this new approach only top level page tables are pre-populated and lower levels are filled dynamically upon memory allocation. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-02 10:42:59 +00:00
/* shallowly populate kasan shadow for vmalloc and modules */
s390/kasan: avoid confusing naming Kasan has nothing to do with vmemmap, strip vmemmap from function names to avoid confusing people. Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-05 07:13:15 +00:00
kasan_early_pgtable_populate(__sha(untracked_mem_end), __sha(kasan_vmax),
POPULATE_SHALLOW);
s390/kasan: add KASAN_VMALLOC support Add KASAN_VMALLOC support which now enables vmalloc memory area access checks as well as enables usage of VMAP_STACK under kasan. KASAN_VMALLOC changes the way vmalloc and modules areas shadow memory is handled. With this new approach only top level page tables are pre-populated and lower levels are filled dynamically upon memory allocation. Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2019-08-02 10:42:59 +00:00
}
/* populate kasan shadow for untracked memory */
s390: unify identity mapping limits handling Currently we have to consider too many different values which in the end only affect identity mapping size. These are: 1. max_physmem_end - end of physical memory online or standby. Always <= end of the last online memory block (get_mem_detect_end()). 2. CONFIG_MAX_PHYSMEM_BITS - the maximum size of physical memory the kernel is able to support. 3. "mem=" kernel command line option which limits physical memory usage. 4. OLDMEM_BASE which is a kdump memory limit when the kernel is executed as crash kernel. 5. "hsa" size which is a memory limit when the kernel is executed during zfcp/nvme dump. Through out kernel startup and run we juggle all those values at once but that does not bring any amusement, only confusion and complexity. Unify all those values to a single one we should really care, that is our identity mapping size. Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Acked-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-19 09:01:33 +00:00
kasan_early_pgtable_populate(__sha(ident_map_size), __sha(untracked_mem_end),
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
POPULATE_ZERO_SHADOW);
s390/kasan: avoid confusing naming Kasan has nothing to do with vmemmap, strip vmemmap from function names to avoid confusing people. Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-05 07:13:15 +00:00
kasan_early_pgtable_populate(__sha(kasan_vmax), __sha(vmax_unlimited),
s390/kasan: support protvirt with 4-level paging Currently the kernel crashes in Kasan instrumentation code if CONFIG_KASAN_S390_4_LEVEL_PAGING is used on protected virtualization capable machine where the ultravisor imposes addressing limitations on the host and those limitations are lower then KASAN_SHADOW_OFFSET. The problem is that Kasan has to know in advance where vmalloc/modules areas would be. With protected virtualization enabled vmalloc/modules areas are moved down to the ultravisor secure storage limit while kasan still expects them at the very end of 4-level paging address space. To fix that make Kasan recognize when protected virtualization is enabled and predefine vmalloc/modules areas position which are compliant with ultravisor secure storage limit. Kasan shadow itself stays in place and might reside above that ultravisor secure storage limit. One slight difference compaired to a kernel without Kasan enabled is that vmalloc/modules areas position is not reverted to default if ultravisor initialization fails. It would still be below the ultravisor secure storage limit. Kernel layout with kasan, 4-level paging and protected virtualization enabled (ultravisor secure storage limit is at 0x0000800000000000): ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400080000000 ---[ vmemmap Area End ]--- ---[ vmalloc Area Start ]--- 0x00007fe000000000-0x00007fff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x00007fff80000000-0x0000800000000000 ---[ Modules Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- 0x001c000000000000-0x0020000000000000 1P PGD I Kernel layout with kasan, 4-level paging and protected virtualization disabled/unsupported: ---[ vmemmap Area Start ]--- 0x0000400000000000-0x0000400060000000 ---[ vmemmap Area End ]--- ---[ Kasan Shadow Start ]--- 0x0018000000000000-0x001c000000000000 ---[ Kasan Shadow End ]--- ---[ vmalloc Area Start ]--- 0x001fffe000000000-0x001fffff80000000 ---[ vmalloc Area End ]--- ---[ Modules Area Start ]--- 0x001fffff80000000-0x0020000000000000 ---[ Modules Area End ]--- Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2020-09-11 09:44:47 +00:00
POPULATE_ZERO_SHADOW);
s390/kasan: free early identity mapping structures Kasan initialization code is changed to populate persistent shadow first, save allocator position into pgalloc_freeable and proceed with early identity mapping creation. This way early identity mapping paging structures could be freed at once after switching to swapper_pg_dir when early identity mapping is not needed anymore. Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-20 11:56:10 +00:00
/* memory allocated for identity mapping structs will be freed later */
pgalloc_freeable = pgalloc_pos;
/* populate identity mapping */
s390/kasan: avoid confusing naming Kasan has nothing to do with vmemmap, strip vmemmap from function names to avoid confusing people. Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-05 07:13:15 +00:00
kasan_early_pgtable_populate(0, memsize, POPULATE_ONE2ONE);
s390/kasan: remove 3-level paging support Compiling the kernel with Kasan disables automatic 3-level vs 4-level kernel space paging selection, because the shadow memory offset has to be known at compile time and there is no such offset which would be acceptable for both 3 and 4-level paging. Instead S390_4_LEVEL_PAGING option was introduced which allowed to pick how many paging levels to use under Kasan. With the introduction of protected virtualization, kernel memory layout may be affected due to ultravisor secure storage limit. This adds additional complexity into how memory layout would look like in combination with Kasan predefined shadow memory offsets. To simplify this make Kasan 4-level paging default and remove Kasan 3-level paging support. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-15 08:01:42 +00:00
kasan_set_pgd(early_pg_dir, _ASCE_TYPE_REGION2);
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
kasan_enable_dat();
/* enable kasan */
init_task.kasan_depth = 0;
memblock_reserve(pgalloc_pos, memsize - pgalloc_pos);
sclp_early_printk("KernelAddressSanitizer initialized\n");
}
s390/kasan: remove obvious parameter with the only possible value Kasan early code is only working on init_mm, remove unneeded pgd parameter from kasan_copy_shadow and rename it to kasan_copy_shadow_mapping. Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-05 08:28:48 +00:00
void __init kasan_copy_shadow_mapping(void)
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
{
/*
* At this point we are still running on early pages setup early_pg_dir,
* while swapper_pg_dir has just been initialized with identity mapping.
* Carry over shadow memory region from early_pg_dir to swapper_pg_dir.
*/
pgd_t *pg_dir_src;
pgd_t *pg_dir_dst;
p4d_t *p4_dir_src;
p4d_t *p4_dir_dst;
pg_dir_src = pgd_offset_raw(early_pg_dir, KASAN_SHADOW_START);
s390/kasan: remove obvious parameter with the only possible value Kasan early code is only working on init_mm, remove unneeded pgd parameter from kasan_copy_shadow and rename it to kasan_copy_shadow_mapping. Reviewed-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-05 08:28:48 +00:00
pg_dir_dst = pgd_offset_raw(init_mm.pgd, KASAN_SHADOW_START);
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
p4_dir_src = p4d_offset(pg_dir_src, KASAN_SHADOW_START);
p4_dir_dst = p4d_offset(pg_dir_dst, KASAN_SHADOW_START);
s390/kasan: remove 3-level paging support Compiling the kernel with Kasan disables automatic 3-level vs 4-level kernel space paging selection, because the shadow memory offset has to be known at compile time and there is no such offset which would be acceptable for both 3 and 4-level paging. Instead S390_4_LEVEL_PAGING option was introduced which allowed to pick how many paging levels to use under Kasan. With the introduction of protected virtualization, kernel memory layout may be affected due to ultravisor secure storage limit. This adds additional complexity into how memory layout would look like in combination with Kasan predefined shadow memory offsets. To simplify this make Kasan 4-level paging default and remove Kasan 3-level paging support. Suggested-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
2020-10-15 08:01:42 +00:00
memcpy(p4_dir_dst, p4_dir_src,
(KASAN_SHADOW_SIZE >> P4D_SHIFT) * sizeof(p4d_t));
s390/kasan: add initialization code and enable it Kasan needs 1/8 of kernel virtual address space to be reserved as the shadow area. And eventually it requires the shadow memory offset to be known at compile time (passed to the compiler when full instrumentation is enabled). Any value picked as the shadow area offset for 3-level paging would eat up identity mapping on 4-level paging (with 1PB shadow area size). So, the kernel sticks to 3-level paging when kasan is enabled. 3TB border is picked as the shadow offset. The memory layout is adjusted so, that physical memory border does not exceed KASAN_SHADOW_START and vmemmap does not go below KASAN_SHADOW_END. Due to the fact that on s390 paging is set up very late and to cover more code with kasan instrumentation, temporary identity mapping and final shadow memory are set up early. The shadow memory mapping is later carried over to init_mm.pgd during paging_init. For the needs of paging structures allocation and shadow memory population a primitive allocator is used, which simply chops off memory blocks from the end of the physical memory. Kasan currenty doesn't track vmemmap and vmalloc areas. Current memory layout (for 3-level paging, 2GB physical memory). ---[ Identity Mapping ]--- 0x0000000000000000-0x0000000000100000 ---[ Kernel Image Start ]--- 0x0000000000100000-0x0000000002b00000 ---[ Kernel Image End ]--- 0x0000000002b00000-0x0000000080000000 2G <- physical memory border 0x0000000080000000-0x0000030000000000 3070G PUD I ---[ Kasan Shadow Start ]--- 0x0000030000000000-0x0000030010000000 256M PMD RW X <- shadow for 2G memory 0x0000030010000000-0x0000037ff0000000 523776M PTE RO NX <- kasan zero ro page 0x0000037ff0000000-0x0000038000000000 256M PMD RW X <- shadow for 2G modules ---[ Kasan Shadow End ]--- 0x0000038000000000-0x000003d100000000 324G PUD I ---[ vmemmap Area ]--- 0x000003d100000000-0x000003e080000000 ---[ vmalloc Area ]--- 0x000003e080000000-0x000003ff80000000 ---[ Modules Area ]--- 0x000003ff80000000-0x0000040000000000 2G Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-17 13:29:13 +00:00
}
s390/kasan: free early identity mapping structures Kasan initialization code is changed to populate persistent shadow first, save allocator position into pgalloc_freeable and proceed with early identity mapping creation. This way early identity mapping paging structures could be freed at once after switching to swapper_pg_dir when early identity mapping is not needed anymore. Reviewed-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-11-20 11:56:10 +00:00
void __init kasan_free_early_identity(void)
{
memblock_free(pgalloc_pos, pgalloc_freeable - pgalloc_pos);
}
Reference in New Issue Copy Permalink