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x86: kmsan: pgtable: reduce vmalloc space

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KMSAN is going to use 3/4 of existing vmalloc space to hold the metadata,
therefore we lower VMALLOC_END to make sure vmalloc() doesn't allocate
past the first 1/4.

Link: https://lkml.kernel.org/r/20220915150417.722975-10-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Alexander Potapenko 2022-09-15 17:03:43 +02:00 committed by Andrew Morton
parent 5de0ce85f5
commit 1a167ddd3c
2 changed files with 47 additions and 2 deletions
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47
arch/x86/include/asm/pgtable_64_types.h
View File

@ -139,7 +139,52 @@ extern unsigned int ptrs_per_p4d;
# define VMEMMAP_START __VMEMMAP_BASE_L4
#endif /* CONFIG_DYNAMIC_MEMORY_LAYOUT */
#define VMALLOC_END (VMALLOC_START + (VMALLOC_SIZE_TB << 40) - 1)
/*
* End of the region for which vmalloc page tables are pre-allocated.
* For non-KMSAN builds, this is the same as VMALLOC_END.
* For KMSAN builds, VMALLOC_START..VMEMORY_END is 4 times bigger than
* VMALLOC_START..VMALLOC_END (see below).
*/
#define VMEMORY_END (VMALLOC_START + (VMALLOC_SIZE_TB << 40) - 1)
#ifndef CONFIG_KMSAN
#define VMALLOC_END VMEMORY_END
#else
/*
* In KMSAN builds vmalloc area is four times smaller, and the remaining 3/4
* are used to keep the metadata for virtual pages. The memory formerly
* belonging to vmalloc area is now laid out as follows:
*
* 1st quarter: VMALLOC_START to VMALLOC_END - new vmalloc area
* 2nd quarter: KMSAN_VMALLOC_SHADOW_START to
* VMALLOC_END+KMSAN_VMALLOC_SHADOW_OFFSET - vmalloc area shadow
* 3rd quarter: KMSAN_VMALLOC_ORIGIN_START to
* VMALLOC_END+KMSAN_VMALLOC_ORIGIN_OFFSET - vmalloc area origins
* 4th quarter: KMSAN_MODULES_SHADOW_START to KMSAN_MODULES_ORIGIN_START
* - shadow for modules,
* KMSAN_MODULES_ORIGIN_START to
* KMSAN_MODULES_ORIGIN_START + MODULES_LEN - origins for modules.
*/
#define VMALLOC_QUARTER_SIZE ((VMALLOC_SIZE_TB << 40) >> 2)
#define VMALLOC_END (VMALLOC_START + VMALLOC_QUARTER_SIZE - 1)
/*
* vmalloc metadata addresses are calculated by adding shadow/origin offsets
* to vmalloc address.
*/
#define KMSAN_VMALLOC_SHADOW_OFFSET VMALLOC_QUARTER_SIZE
#define KMSAN_VMALLOC_ORIGIN_OFFSET (VMALLOC_QUARTER_SIZE << 1)
#define KMSAN_VMALLOC_SHADOW_START (VMALLOC_START + KMSAN_VMALLOC_SHADOW_OFFSET)
#define KMSAN_VMALLOC_ORIGIN_START (VMALLOC_START + KMSAN_VMALLOC_ORIGIN_OFFSET)
/*
* The shadow/origin for modules are placed one by one in the last 1/4 of
* vmalloc space.
*/
#define KMSAN_MODULES_SHADOW_START (VMALLOC_END + KMSAN_VMALLOC_ORIGIN_OFFSET + 1)
#define KMSAN_MODULES_ORIGIN_START (KMSAN_MODULES_SHADOW_START + MODULES_LEN)
#endif /* CONFIG_KMSAN */
#define MODULES_VADDR (__START_KERNEL_map + KERNEL_IMAGE_SIZE)
/* The module sections ends with the start of the fixmap */

2
arch/x86/mm/init_64.c
View File

@ -1287,7 +1287,7 @@ static void __init preallocate_vmalloc_pages(void)
unsigned long addr;
const char *lvl;
for (addr = VMALLOC_START; addr <= VMALLOC_END; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
for (addr = VMALLOC_START; addr <= VMEMORY_END; addr = ALIGN(addr + 1, PGDIR_SIZE)) {
pgd_t *pgd = pgd_offset_k(addr);
p4d_t *p4d;
pud_t *pud;