License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 14:07:57 +00:00
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/* SPDX-License-Identifier: GPL-2.0 */
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2005-04-16 22:20:36 +00:00
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/*
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* linux/boot/head.S
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*
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* Copyright (C) 1991, 1992, 1993 Linus Torvalds
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*/
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/*
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* head.S contains the 32-bit startup code.
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*
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* NOTE!!! Startup happens at absolute address 0x00001000, which is also where
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* the page directory will exist. The startup code will be overwritten by
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* the page directory. [According to comments etc elsewhere on a compressed
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* kernel it will end up at 0x1000 + 1Mb I hope so as I assume this. - AC]
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*
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* Page 0 is deliberately kept safe, since System Management Mode code in
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* laptops may need to access the BIOS data stored there. This is also
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* useful for future device drivers that either access the BIOS via VM86
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* mode.
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*/
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/*
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2005-06-25 21:58:59 +00:00
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* High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996
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2005-04-16 22:20:36 +00:00
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*/
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2009-05-08 22:59:13 +00:00
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.code32
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.text
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2005-04-16 22:20:36 +00:00
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2009-09-16 20:44:27 +00:00
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#include <linux/init.h>
|
2005-04-16 22:20:36 +00:00
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#include <linux/linkage.h>
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#include <asm/segment.h>
|
2008-04-08 10:54:30 +00:00
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#include <asm/boot.h>
|
2007-05-02 17:27:07 +00:00
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#include <asm/msr.h>
|
2008-05-12 13:43:39 +00:00
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#include <asm/processor-flags.h>
|
2007-10-26 17:29:04 +00:00
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#include <asm/asm-offsets.h>
|
2015-02-19 07:34:58 +00:00
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#include <asm/bootparam.h>
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2005-04-16 22:20:36 +00:00
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x86/build: Build compressed x86 kernels as PIE
The 32-bit x86 assembler in binutils 2.26 will generate R_386_GOT32X
relocation to get the symbol address in PIC. When the compressed x86
kernel isn't built as PIC, the linker optimizes R_386_GOT32X relocations
to their fixed symbol addresses. However, when the compressed x86
kernel is loaded at a different address, it leads to the following
load failure:
Failed to allocate space for phdrs
during the decompression stage.
If the compressed x86 kernel is relocatable at run-time, it should be
compiled with -fPIE, instead of -fPIC, if possible and should be built as
Position Independent Executable (PIE) so that linker won't optimize
R_386_GOT32X relocation to its fixed symbol address.
Older linkers generate R_386_32 relocations against locally defined
symbols, _bss, _ebss, _got and _egot, in PIE. It isn't wrong, just less
optimal than R_386_RELATIVE. But the x86 kernel fails to properly handle
R_386_32 relocations when relocating the kernel. To generate
R_386_RELATIVE relocations, we mark _bss, _ebss, _got and _egot as
hidden in both 32-bit and 64-bit x86 kernels.
To build a 64-bit compressed x86 kernel as PIE, we need to disable the
relocation overflow check to avoid relocation overflow errors. We do
this with a new linker command-line option, -z noreloc-overflow, which
got added recently:
commit 4c10bbaa0912742322f10d9d5bb630ba4e15dfa7
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Tue Mar 15 11:07:06 2016 -0700
Add -z noreloc-overflow option to x86-64 ld
Add -z noreloc-overflow command-line option to the x86-64 ELF linker to
disable relocation overflow check. This can be used to avoid relocation
overflow check if there will be no dynamic relocation overflow at
run-time.
The 64-bit compressed x86 kernel is built as PIE only if the linker supports
-z noreloc-overflow. So far 64-bit relocatable compressed x86 kernel
boots fine even when it is built as a normal executable.
Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
[ Edited the changelog and comments. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-17 03:04:35 +00:00
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/*
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* Locally defined symbols should be marked hidden:
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*/
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.hidden _bss
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.hidden _ebss
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.hidden _got
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.hidden _egot
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|
2009-09-16 20:44:27 +00:00
|
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__HEAD
|
2005-04-16 22:20:36 +00:00
|
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.code32
|
2009-02-13 21:50:22 +00:00
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ENTRY(startup_32)
|
2013-01-24 20:20:07 +00:00
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/*
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* 32bit entry is 0 and it is ABI so immutable!
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* If we come here directly from a bootloader,
|
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* kernel(text+data+bss+brk) ramdisk, zero_page, command line
|
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* all need to be under the 4G limit.
|
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*/
|
2005-04-16 22:20:36 +00:00
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cld
|
2009-05-08 22:59:13 +00:00
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/*
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* Test KEEP_SEGMENTS flag to see if the bootloader is asking
|
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|
|
* us to not reload segments
|
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*/
|
2015-02-19 07:34:58 +00:00
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testb $KEEP_SEGMENTS, BP_loadflags(%esi)
|
2007-10-26 17:29:04 +00:00
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jnz 1f
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|
2005-04-16 22:20:36 +00:00
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cli
|
2013-03-01 01:20:39 +00:00
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movl $(__BOOT_DS), %eax
|
2007-05-02 17:27:07 +00:00
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movl %eax, %ds
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movl %eax, %es
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movl %eax, %ss
|
2007-10-26 17:29:04 +00:00
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1:
|
2007-05-02 17:27:07 +00:00
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|
2009-05-08 22:59:13 +00:00
|
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/*
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|
|
* Calculate the delta between where we were compiled to run
|
2007-05-02 17:27:07 +00:00
|
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* at and where we were actually loaded at. This can only be done
|
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* with a short local call on x86. Nothing else will tell us what
|
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* address we are running at. The reserved chunk of the real-mode
|
2007-07-11 19:18:33 +00:00
|
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* data at 0x1e4 (defined as a scratch field) are used as the stack
|
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* for this calculation. Only 4 bytes are needed.
|
2007-05-02 17:27:07 +00:00
|
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|
*/
|
2009-05-06 06:24:50 +00:00
|
|
|
leal (BP_scratch+4)(%esi), %esp
|
2007-05-02 17:27:07 +00:00
|
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|
call 1f
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1: popl %ebp
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subl $1b, %ebp
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|
2007-05-02 17:27:08 +00:00
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/* setup a stack and make sure cpu supports long mode. */
|
2008-04-08 10:54:30 +00:00
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movl $boot_stack_end, %eax
|
2007-05-02 17:27:08 +00:00
|
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|
addl %ebp, %eax
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|
movl %eax, %esp
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|
call verify_cpu
|
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testl %eax, %eax
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jnz no_longmode
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|
2009-05-08 22:59:13 +00:00
|
|
|
/*
|
|
|
|
|
* Compute the delta between where we were compiled to run at
|
2007-05-02 17:27:07 +00:00
|
|
|
* and where the code will actually run at.
|
2009-05-08 22:59:13 +00:00
|
|
|
*
|
|
|
|
|
* %ebp contains the address we are loaded at by the boot loader and %ebx
|
2007-05-02 17:27:07 +00:00
|
|
|
* contains the address where we should move the kernel image temporarily
|
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|
* for safe in-place decompression.
|
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|
*/
|
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|
#ifdef CONFIG_RELOCATABLE
|
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|
movl %ebp, %ebx
|
2009-05-11 22:56:08 +00:00
|
|
|
movl BP_kernel_alignment(%esi), %eax
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|
decl %eax
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|
|
addl %eax, %ebx
|
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|
notl %eax
|
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|
andl %eax, %ebx
|
2013-10-11 00:18:14 +00:00
|
|
|
cmpl $LOAD_PHYSICAL_ADDR, %ebx
|
|
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|
|
jge 1f
|
2007-05-02 17:27:07 +00:00
|
|
|
#endif
|
2013-10-11 00:18:14 +00:00
|
|
|
movl $LOAD_PHYSICAL_ADDR, %ebx
|
|
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|
1:
|
2007-05-02 17:27:07 +00:00
|
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|
2009-05-09 00:42:16 +00:00
|
|
|
/* Target address to relocate to for decompression */
|
x86/boot: Move compressed kernel to the end of the decompression buffer
This change makes later calculations about where the kernel is located
easier to reason about. To better understand this change, we must first
clarify what 'VO' and 'ZO' are. These values were introduced in commits
by hpa:
77d1a4999502 ("x86, boot: make symbols from the main vmlinux available")
37ba7ab5e33c ("x86, boot: make kernel_alignment adjustable; new bzImage fields")
Specifically:
All names prefixed with 'VO_':
- relate to the uncompressed kernel image
- the size of the VO image is: VO__end-VO__text ("VO_INIT_SIZE" define)
All names prefixed with 'ZO_':
- relate to the bootable compressed kernel image (boot/compressed/vmlinux),
which is composed of the following memory areas:
- head text
- compressed kernel (VO image and relocs table)
- decompressor code
- the size of the ZO image is: ZO__end - ZO_startup_32 ("ZO_INIT_SIZE" define, though see below)
The 'INIT_SIZE' value is used to find the larger of the two image sizes:
#define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_z_extract_offset)
#define VO_INIT_SIZE (VO__end - VO__text)
#if ZO_INIT_SIZE > VO_INIT_SIZE
# define INIT_SIZE ZO_INIT_SIZE
#else
# define INIT_SIZE VO_INIT_SIZE
#endif
The current code uses extract_offset to decide where to position the
copied ZO (i.e. ZO starts at extract_offset). (This is why ZO_INIT_SIZE
currently includes the extract_offset.)
Why does z_extract_offset exist? It's needed because we are trying to minimize
the amount of RAM used for the whole act of creating an uncompressed, executable,
properly relocation-linked kernel image in system memory. We do this so that
kernels can be booted on even very small systems.
To achieve the goal of minimal memory consumption we have implemented an in-place
decompression strategy: instead of cleanly separating the VO and ZO images and
also allocating some memory for the decompression code's runtime needs, we instead
create this elaborate layout of memory buffers where the output (decompressed)
stream, as it progresses, overlaps with and destroys the input (compressed)
stream. This can only be done safely if the ZO image is placed to the end of the
VO range, plus a certain amount of safety distance to make sure that when the last
bytes of the VO range are decompressed, the compressed stream pointer is safely
beyond the end of the VO range.
z_extract_offset is calculated in arch/x86/boot/compressed/mkpiggy.c during
the build process, at a point when we know the exact compressed and
uncompressed size of the kernel images and can calculate this safe minimum
offset value. (Note that the mkpiggy.c calculation is not perfect, because
we don't know the decompressor used at that stage, so the z_extract_offset
calculation is necessarily imprecise and is mostly based on gzip internals -
we'll improve that in the next patch.)
When INIT_SIZE is bigger than VO_INIT_SIZE (uncommon but possible),
the copied ZO occupies the memory from extract_offset to the end of
decompression buffer. It overlaps with the soon-to-be-uncompressed kernel
like this:
|-----compressed kernel image------|
V V
0 extract_offset +INIT_SIZE
|-----------|---------------|-------------------------|--------|
| | | |
VO__text startup_32 of ZO VO__end ZO__end
^ ^
|-------uncompressed kernel image---------|
When INIT_SIZE is equal to VO_INIT_SIZE (likely) there's still space
left from end of ZO to the end of decompressing buffer, like below.
|-compressed kernel image-|
V V
0 extract_offset +INIT_SIZE
|-----------|---------------|-------------------------|--------|
| | | |
VO__text startup_32 of ZO ZO__end VO__end
^ ^
|------------uncompressed kernel image-------------|
To simplify calculations and avoid special cases, it is cleaner to
always place the compressed kernel image in memory so that ZO__end
is at the end of the decompression buffer, instead of placing t at
the start of extract_offset as is currently done.
This patch adds BP_init_size (which is the INIT_SIZE as passed in from
the boot_params) into asm-offsets.c to make it visible to the assembly
code.
Then when moving the ZO, it calculates the starting position of
the copied ZO (via BP_init_size and the ZO run size) so that the VO__end
will be at the end of the decompression buffer. To make the position
calculation safe, the end of ZO is page aligned (and a comment is added
to the existing VO alignment for good measure).
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
[ Rewrote changelog and comments. ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: lasse.collin@tukaani.org
Link: http://lkml.kernel.org/r/1461888548-32439-3-git-send-email-keescook@chromium.org
[ Rewrote the changelog some more. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-29 00:09:04 +00:00
|
|
|
movl BP_init_size(%esi), %eax
|
|
|
|
|
subl $_end, %eax
|
|
|
|
|
addl %eax, %ebx
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
|
/*
|
2007-05-02 17:27:07 +00:00
|
|
|
* Prepare for entering 64 bit mode
|
2005-04-16 22:20:36 +00:00
|
|
|
*/
|
2007-05-02 17:27:07 +00:00
|
|
|
|
|
|
|
|
/* Load new GDT with the 64bit segments using 32bit descriptor */
|
2016-11-01 15:49:24 +00:00
|
|
|
addl %ebp, gdt+2(%ebp)
|
2007-05-02 17:27:07 +00:00
|
|
|
lgdt gdt(%ebp)
|
|
|
|
|
|
|
|
|
|
/* Enable PAE mode */
|
2014-02-24 13:37:29 +00:00
|
|
|
movl %cr4, %eax
|
|
|
|
|
orl $X86_CR4_PAE, %eax
|
2007-05-02 17:27:07 +00:00
|
|
|
movl %eax, %cr4
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Build early 4G boot pagetable
|
|
|
|
|
*/
|
2017-10-20 14:30:54 +00:00
|
|
|
/*
|
|
|
|
|
* If SEV is active then set the encryption mask in the page tables.
|
|
|
|
|
* This will insure that when the kernel is copied and decompressed
|
|
|
|
|
* it will be done so encrypted.
|
|
|
|
|
*/
|
|
|
|
|
call get_sev_encryption_bit
|
|
|
|
|
xorl %edx, %edx
|
|
|
|
|
testl %eax, %eax
|
|
|
|
|
jz 1f
|
|
|
|
|
subl $32, %eax /* Encryption bit is always above bit 31 */
|
|
|
|
|
bts %eax, %edx /* Set encryption mask for page tables */
|
|
|
|
|
1:
|
|
|
|
|
|
2009-05-08 22:59:13 +00:00
|
|
|
/* Initialize Page tables to 0 */
|
2007-05-02 17:27:07 +00:00
|
|
|
leal pgtable(%ebx), %edi
|
|
|
|
|
xorl %eax, %eax
|
x86/KASLR: Build identity mappings on demand
Currently KASLR only supports relocation in a small physical range (from
16M to 1G), due to using the initial kernel page table identity mapping.
To support ranges above this, we need to have an identity mapping for the
desired memory range before we can decompress (and later run) the kernel.
32-bit kernels already have the needed identity mapping. This patch adds
identity mappings for the needed memory ranges on 64-bit kernels. This
happens in two possible boot paths:
If loaded via startup_32(), we need to set up the needed identity map.
If loaded from a 64-bit bootloader, the bootloader will have already
set up an identity mapping, and we'll start via the compressed kernel's
startup_64(). In this case, the bootloader's page tables need to be
avoided while selecting the new uncompressed kernel location. If not,
the decompressor could overwrite them during decompression.
To accomplish this, we could walk the pagetable and find every page
that is used, and add them to mem_avoid, but this needs extra code and
will require increasing the size of the mem_avoid array.
Instead, we can create a new set of page tables for our own identity
mapping instead. The pages for the new page table will come from the
_pagetable section of the compressed kernel, which means they are
already contained by in mem_avoid array. To do this, we reuse the code
from the uncompressed kernel's identity mapping routines.
The _pgtable will be shared by both the 32-bit and 64-bit paths to reduce
init_size, as now the compressed kernel's _rodata to _end will contribute
to init_size.
To handle the possible mappings, we need to increase the existing page
table buffer size:
When booting via startup_64(), we need to cover the old VO, params,
cmdline and uncompressed kernel. In an extreme case we could have them
all beyond the 512G boundary, which needs (2+2)*4 pages with 2M mappings.
And we'll need 2 for first 2M for VGA RAM. One more is needed for level4.
This gets us to 19 pages total.
When booting via startup_32(), KASLR could move the uncompressed kernel
above 4G, so we need to create extra identity mappings, which should only
need (2+2) pages at most when it is beyond the 512G boundary. So 19
pages is sufficient for this case as well.
The resulting BOOT_*PGT_SIZE defines use the "_SIZE" suffix on their
names to maintain logical consistency with the existing BOOT_HEAP_SIZE
and BOOT_STACK_SIZE defines.
This patch is based on earlier patches from Yinghai Lu and Baoquan He.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: kernel-hardening@lists.openwall.com
Cc: lasse.collin@tukaani.org
Link: http://lkml.kernel.org/r/1462572095-11754-4-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-06 22:01:35 +00:00
|
|
|
movl $(BOOT_INIT_PGT_SIZE/4), %ecx
|
2007-05-02 17:27:07 +00:00
|
|
|
rep stosl
|
|
|
|
|
|
|
|
|
|
/* Build Level 4 */
|
|
|
|
|
leal pgtable + 0(%ebx), %edi
|
|
|
|
|
leal 0x1007 (%edi), %eax
|
|
|
|
|
movl %eax, 0(%edi)
|
2017-10-20 14:30:54 +00:00
|
|
|
addl %edx, 4(%edi)
|
2007-05-02 17:27:07 +00:00
|
|
|
|
|
|
|
|
/* Build Level 3 */
|
|
|
|
|
leal pgtable + 0x1000(%ebx), %edi
|
|
|
|
|
leal 0x1007(%edi), %eax
|
|
|
|
|
movl $4, %ecx
|
|
|
|
|
1: movl %eax, 0x00(%edi)
|
2017-10-20 14:30:54 +00:00
|
|
|
addl %edx, 0x04(%edi)
|
2007-05-02 17:27:07 +00:00
|
|
|
addl $0x00001000, %eax
|
|
|
|
|
addl $8, %edi
|
|
|
|
|
decl %ecx
|
|
|
|
|
jnz 1b
|
|
|
|
|
|
|
|
|
|
/* Build Level 2 */
|
|
|
|
|
leal pgtable + 0x2000(%ebx), %edi
|
|
|
|
|
movl $0x00000183, %eax
|
|
|
|
|
movl $2048, %ecx
|
|
|
|
|
1: movl %eax, 0(%edi)
|
2017-10-20 14:30:54 +00:00
|
|
|
addl %edx, 4(%edi)
|
2007-05-02 17:27:07 +00:00
|
|
|
addl $0x00200000, %eax
|
|
|
|
|
addl $8, %edi
|
|
|
|
|
decl %ecx
|
|
|
|
|
jnz 1b
|
|
|
|
|
|
|
|
|
|
/* Enable the boot page tables */
|
|
|
|
|
leal pgtable(%ebx), %eax
|
|
|
|
|
movl %eax, %cr3
|
|
|
|
|
|
|
|
|
|
/* Enable Long mode in EFER (Extended Feature Enable Register) */
|
|
|
|
|
movl $MSR_EFER, %ecx
|
|
|
|
|
rdmsr
|
|
|
|
|
btsl $_EFER_LME, %eax
|
|
|
|
|
wrmsr
|
|
|
|
|
|
2013-01-24 20:20:01 +00:00
|
|
|
/* After gdt is loaded */
|
|
|
|
|
xorl %eax, %eax
|
|
|
|
|
lldt %ax
|
2015-04-01 14:50:58 +00:00
|
|
|
movl $__BOOT_TSS, %eax
|
2013-01-24 20:20:01 +00:00
|
|
|
ltr %ax
|
|
|
|
|
|
2009-05-08 22:59:13 +00:00
|
|
|
/*
|
|
|
|
|
* Setup for the jump to 64bit mode
|
2007-05-02 17:27:07 +00:00
|
|
|
*
|
|
|
|
|
* When the jump is performend we will be in long mode but
|
|
|
|
|
* in 32bit compatibility mode with EFER.LME = 1, CS.L = 0, CS.D = 1
|
|
|
|
|
* (and in turn EFER.LMA = 1). To jump into 64bit mode we use
|
|
|
|
|
* the new gdt/idt that has __KERNEL_CS with CS.L = 1.
|
|
|
|
|
* We place all of the values on our mini stack so lret can
|
|
|
|
|
* used to perform that far jump.
|
|
|
|
|
*/
|
|
|
|
|
pushl $__KERNEL_CS
|
|
|
|
|
leal startup_64(%ebp), %eax
|
x86/efi: Firmware agnostic handover entry points
The EFI handover code only works if the "bitness" of the firmware and
the kernel match, i.e. 64-bit firmware and 64-bit kernel - it is not
possible to mix the two. This goes against the tradition that a 32-bit
kernel can be loaded on a 64-bit BIOS platform without having to do
anything special in the boot loader. Linux distributions, for one thing,
regularly run only 32-bit kernels on their live media.
Despite having only one 'handover_offset' field in the kernel header,
EFI boot loaders use two separate entry points to enter the kernel based
on the architecture the boot loader was compiled for,
(1) 32-bit loader: handover_offset
(2) 64-bit loader: handover_offset + 512
Since we already have two entry points, we can leverage them to infer
the bitness of the firmware we're running on, without requiring any boot
loader modifications, by making (1) and (2) valid entry points for both
CONFIG_X86_32 and CONFIG_X86_64 kernels.
To be clear, a 32-bit boot loader will always use (1) and a 64-bit boot
loader will always use (2). It's just that, if a single kernel image
supports (1) and (2) that image can be used with both 32-bit and 64-bit
boot loaders, and hence both 32-bit and 64-bit EFI.
(1) and (2) must be 512 bytes apart at all times, but that is already
part of the boot ABI and we could never change that delta without
breaking existing boot loaders anyhow.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-01-10 15:54:31 +00:00
|
|
|
#ifdef CONFIG_EFI_MIXED
|
|
|
|
|
movl efi32_config(%ebp), %ebx
|
|
|
|
|
cmp $0, %ebx
|
|
|
|
|
jz 1f
|
|
|
|
|
leal handover_entry(%ebp), %eax
|
|
|
|
|
1:
|
|
|
|
|
#endif
|
2007-05-02 17:27:07 +00:00
|
|
|
pushl %eax
|
|
|
|
|
|
|
|
|
|
/* Enter paged protected Mode, activating Long Mode */
|
2008-05-12 13:43:39 +00:00
|
|
|
movl $(X86_CR0_PG | X86_CR0_PE), %eax /* Enable Paging and Protected mode */
|
2007-05-02 17:27:07 +00:00
|
|
|
movl %eax, %cr0
|
|
|
|
|
|
|
|
|
|
/* Jump from 32bit compatibility mode into 64bit mode. */
|
|
|
|
|
lret
|
2009-02-13 21:50:22 +00:00
|
|
|
ENDPROC(startup_32)
|
2007-05-02 17:27:07 +00:00
|
|
|
|
x86/efi: Firmware agnostic handover entry points
The EFI handover code only works if the "bitness" of the firmware and
the kernel match, i.e. 64-bit firmware and 64-bit kernel - it is not
possible to mix the two. This goes against the tradition that a 32-bit
kernel can be loaded on a 64-bit BIOS platform without having to do
anything special in the boot loader. Linux distributions, for one thing,
regularly run only 32-bit kernels on their live media.
Despite having only one 'handover_offset' field in the kernel header,
EFI boot loaders use two separate entry points to enter the kernel based
on the architecture the boot loader was compiled for,
(1) 32-bit loader: handover_offset
(2) 64-bit loader: handover_offset + 512
Since we already have two entry points, we can leverage them to infer
the bitness of the firmware we're running on, without requiring any boot
loader modifications, by making (1) and (2) valid entry points for both
CONFIG_X86_32 and CONFIG_X86_64 kernels.
To be clear, a 32-bit boot loader will always use (1) and a 64-bit boot
loader will always use (2). It's just that, if a single kernel image
supports (1) and (2) that image can be used with both 32-bit and 64-bit
boot loaders, and hence both 32-bit and 64-bit EFI.
(1) and (2) must be 512 bytes apart at all times, but that is already
part of the boot ABI and we could never change that delta without
breaking existing boot loaders anyhow.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-01-10 15:54:31 +00:00
|
|
|
#ifdef CONFIG_EFI_MIXED
|
|
|
|
|
.org 0x190
|
|
|
|
|
ENTRY(efi32_stub_entry)
|
|
|
|
|
add $0x4, %esp /* Discard return address */
|
|
|
|
|
popl %ecx
|
|
|
|
|
popl %edx
|
|
|
|
|
popl %esi
|
|
|
|
|
|
|
|
|
|
leal (BP_scratch+4)(%esi), %esp
|
|
|
|
|
call 1f
|
|
|
|
|
1: pop %ebp
|
|
|
|
|
subl $1b, %ebp
|
|
|
|
|
|
|
|
|
|
movl %ecx, efi32_config(%ebp)
|
|
|
|
|
movl %edx, efi32_config+8(%ebp)
|
|
|
|
|
sgdtl efi32_boot_gdt(%ebp)
|
|
|
|
|
|
|
|
|
|
leal efi32_config(%ebp), %eax
|
|
|
|
|
movl %eax, efi_config(%ebp)
|
|
|
|
|
|
|
|
|
|
jmp startup_32
|
|
|
|
|
ENDPROC(efi32_stub_entry)
|
|
|
|
|
#endif
|
|
|
|
|
|
2007-05-02 17:27:07 +00:00
|
|
|
.code64
|
2007-05-02 17:27:08 +00:00
|
|
|
.org 0x200
|
2007-05-02 17:27:07 +00:00
|
|
|
ENTRY(startup_64)
|
2009-05-08 22:59:13 +00:00
|
|
|
/*
|
2013-01-24 20:20:07 +00:00
|
|
|
* 64bit entry is 0x200 and it is ABI so immutable!
|
2009-05-08 22:59:13 +00:00
|
|
|
* We come here either from startup_32 or directly from a
|
2013-01-24 20:20:07 +00:00
|
|
|
* 64bit bootloader.
|
|
|
|
|
* If we come here from a bootloader, kernel(text+data+bss+brk),
|
|
|
|
|
* ramdisk, zero_page, command line could be above 4G.
|
|
|
|
|
* We depend on an identity mapped page table being provided
|
|
|
|
|
* that maps our entire kernel(text+data+bss+brk), zero page
|
|
|
|
|
* and command line.
|
2007-05-02 17:27:07 +00:00
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
/* Setup data segments. */
|
|
|
|
|
xorl %eax, %eax
|
|
|
|
|
movl %eax, %ds
|
|
|
|
|
movl %eax, %es
|
|
|
|
|
movl %eax, %ss
|
2007-08-10 20:31:05 +00:00
|
|
|
movl %eax, %fs
|
|
|
|
|
movl %eax, %gs
|
2007-05-02 17:27:07 +00:00
|
|
|
|
2009-05-08 22:59:13 +00:00
|
|
|
/*
|
|
|
|
|
* Compute the decompressed kernel start address. It is where
|
2007-05-02 17:27:07 +00:00
|
|
|
* we were loaded at aligned to a 2M boundary. %rbp contains the
|
|
|
|
|
* decompressed kernel start address.
|
|
|
|
|
*
|
|
|
|
|
* If it is a relocatable kernel then decompress and run the kernel
|
|
|
|
|
* from load address aligned to 2MB addr, otherwise decompress and
|
2009-05-11 21:41:55 +00:00
|
|
|
* run the kernel from LOAD_PHYSICAL_ADDR
|
2009-05-09 00:42:16 +00:00
|
|
|
*
|
|
|
|
|
* We cannot rely on the calculation done in 32-bit mode, since we
|
|
|
|
|
* may have been invoked via the 64-bit entry point.
|
2007-05-02 17:27:07 +00:00
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
/* Start with the delta to where the kernel will run at. */
|
|
|
|
|
#ifdef CONFIG_RELOCATABLE
|
|
|
|
|
leaq startup_32(%rip) /* - $startup_32 */, %rbp
|
2009-05-11 22:56:08 +00:00
|
|
|
movl BP_kernel_alignment(%rsi), %eax
|
|
|
|
|
decl %eax
|
|
|
|
|
addq %rax, %rbp
|
|
|
|
|
notq %rax
|
|
|
|
|
andq %rax, %rbp
|
2013-10-11 00:18:14 +00:00
|
|
|
cmpq $LOAD_PHYSICAL_ADDR, %rbp
|
|
|
|
|
jge 1f
|
2007-05-02 17:27:07 +00:00
|
|
|
#endif
|
2013-10-11 00:18:14 +00:00
|
|
|
movq $LOAD_PHYSICAL_ADDR, %rbp
|
|
|
|
|
1:
|
2007-05-02 17:27:07 +00:00
|
|
|
|
2009-05-09 00:42:16 +00:00
|
|
|
/* Target address to relocate to for decompression */
|
x86/boot: Move compressed kernel to the end of the decompression buffer
This change makes later calculations about where the kernel is located
easier to reason about. To better understand this change, we must first
clarify what 'VO' and 'ZO' are. These values were introduced in commits
by hpa:
77d1a4999502 ("x86, boot: make symbols from the main vmlinux available")
37ba7ab5e33c ("x86, boot: make kernel_alignment adjustable; new bzImage fields")
Specifically:
All names prefixed with 'VO_':
- relate to the uncompressed kernel image
- the size of the VO image is: VO__end-VO__text ("VO_INIT_SIZE" define)
All names prefixed with 'ZO_':
- relate to the bootable compressed kernel image (boot/compressed/vmlinux),
which is composed of the following memory areas:
- head text
- compressed kernel (VO image and relocs table)
- decompressor code
- the size of the ZO image is: ZO__end - ZO_startup_32 ("ZO_INIT_SIZE" define, though see below)
The 'INIT_SIZE' value is used to find the larger of the two image sizes:
#define ZO_INIT_SIZE (ZO__end - ZO_startup_32 + ZO_z_extract_offset)
#define VO_INIT_SIZE (VO__end - VO__text)
#if ZO_INIT_SIZE > VO_INIT_SIZE
# define INIT_SIZE ZO_INIT_SIZE
#else
# define INIT_SIZE VO_INIT_SIZE
#endif
The current code uses extract_offset to decide where to position the
copied ZO (i.e. ZO starts at extract_offset). (This is why ZO_INIT_SIZE
currently includes the extract_offset.)
Why does z_extract_offset exist? It's needed because we are trying to minimize
the amount of RAM used for the whole act of creating an uncompressed, executable,
properly relocation-linked kernel image in system memory. We do this so that
kernels can be booted on even very small systems.
To achieve the goal of minimal memory consumption we have implemented an in-place
decompression strategy: instead of cleanly separating the VO and ZO images and
also allocating some memory for the decompression code's runtime needs, we instead
create this elaborate layout of memory buffers where the output (decompressed)
stream, as it progresses, overlaps with and destroys the input (compressed)
stream. This can only be done safely if the ZO image is placed to the end of the
VO range, plus a certain amount of safety distance to make sure that when the last
bytes of the VO range are decompressed, the compressed stream pointer is safely
beyond the end of the VO range.
z_extract_offset is calculated in arch/x86/boot/compressed/mkpiggy.c during
the build process, at a point when we know the exact compressed and
uncompressed size of the kernel images and can calculate this safe minimum
offset value. (Note that the mkpiggy.c calculation is not perfect, because
we don't know the decompressor used at that stage, so the z_extract_offset
calculation is necessarily imprecise and is mostly based on gzip internals -
we'll improve that in the next patch.)
When INIT_SIZE is bigger than VO_INIT_SIZE (uncommon but possible),
the copied ZO occupies the memory from extract_offset to the end of
decompression buffer. It overlaps with the soon-to-be-uncompressed kernel
like this:
|-----compressed kernel image------|
V V
0 extract_offset +INIT_SIZE
|-----------|---------------|-------------------------|--------|
| | | |
VO__text startup_32 of ZO VO__end ZO__end
^ ^
|-------uncompressed kernel image---------|
When INIT_SIZE is equal to VO_INIT_SIZE (likely) there's still space
left from end of ZO to the end of decompressing buffer, like below.
|-compressed kernel image-|
V V
0 extract_offset +INIT_SIZE
|-----------|---------------|-------------------------|--------|
| | | |
VO__text startup_32 of ZO ZO__end VO__end
^ ^
|------------uncompressed kernel image-------------|
To simplify calculations and avoid special cases, it is cleaner to
always place the compressed kernel image in memory so that ZO__end
is at the end of the decompression buffer, instead of placing t at
the start of extract_offset as is currently done.
This patch adds BP_init_size (which is the INIT_SIZE as passed in from
the boot_params) into asm-offsets.c to make it visible to the assembly
code.
Then when moving the ZO, it calculates the starting position of
the copied ZO (via BP_init_size and the ZO run size) so that the VO__end
will be at the end of the decompression buffer. To make the position
calculation safe, the end of ZO is page aligned (and a comment is added
to the existing VO alignment for good measure).
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
[ Rewrote changelog and comments. ]
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: lasse.collin@tukaani.org
Link: http://lkml.kernel.org/r/1461888548-32439-3-git-send-email-keescook@chromium.org
[ Rewrote the changelog some more. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-29 00:09:04 +00:00
|
|
|
movl BP_init_size(%rsi), %ebx
|
|
|
|
|
subl $_end, %ebx
|
|
|
|
|
addq %rbp, %rbx
|
2007-05-02 17:27:07 +00:00
|
|
|
|
2009-05-08 23:27:41 +00:00
|
|
|
/* Set up the stack */
|
|
|
|
|
leaq boot_stack_end(%rbx), %rsp
|
|
|
|
|
|
2017-06-06 11:31:25 +00:00
|
|
|
/*
|
|
|
|
|
* At this point we are in long mode with 4-level paging enabled,
|
|
|
|
|
* but we want to enable 5-level paging.
|
|
|
|
|
*
|
|
|
|
|
* The problem is that we cannot do it directly. Setting LA57 in
|
|
|
|
|
* long mode would trigger #GP. So we need to switch off long mode
|
|
|
|
|
* first.
|
2018-02-09 14:22:26 +00:00
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* paging_prepare() sets up the trampoline and checks if we need to
|
|
|
|
|
* enable 5-level paging.
|
2017-06-06 11:31:25 +00:00
|
|
|
*
|
2018-02-09 14:22:26 +00:00
|
|
|
* Address of the trampoline is returned in RAX.
|
|
|
|
|
* Non zero RDX on return means we need to enable 5-level paging.
|
2017-06-06 11:31:25 +00:00
|
|
|
*
|
2018-02-09 14:22:26 +00:00
|
|
|
* RSI holds real mode data and needs to be preserved across
|
|
|
|
|
* this function call.
|
2017-06-06 11:31:25 +00:00
|
|
|
*/
|
2018-02-09 14:22:26 +00:00
|
|
|
pushq %rsi
|
|
|
|
|
call paging_prepare
|
|
|
|
|
popq %rsi
|
|
|
|
|
|
|
|
|
|
/* Save the trampoline address in RCX */
|
|
|
|
|
movq %rax, %rcx
|
|
|
|
|
|
|
|
|
|
/* Check if we need to enable 5-level paging */
|
|
|
|
|
cmpq $0, %rdx
|
|
|
|
|
jz lvl5
|
2017-06-06 11:31:25 +00:00
|
|
|
|
|
|
|
|
/* Clear additional page table */
|
|
|
|
|
leaq lvl5_pgtable(%rbx), %rdi
|
|
|
|
|
xorq %rax, %rax
|
|
|
|
|
movq $(PAGE_SIZE/8), %rcx
|
|
|
|
|
rep stosq
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Setup current CR3 as the first and only entry in a new top level
|
|
|
|
|
* page table.
|
|
|
|
|
*/
|
|
|
|
|
movq %cr3, %rdi
|
|
|
|
|
leaq 0x7 (%rdi), %rax
|
|
|
|
|
movq %rax, lvl5_pgtable(%rbx)
|
|
|
|
|
|
|
|
|
|
/* Switch to compatibility mode (CS.L = 0 CS.D = 1) via far return */
|
|
|
|
|
pushq $__KERNEL32_CS
|
|
|
|
|
leaq compatible_mode(%rip), %rax
|
|
|
|
|
pushq %rax
|
|
|
|
|
lretq
|
|
|
|
|
lvl5:
|
|
|
|
|
|
2009-05-08 23:27:41 +00:00
|
|
|
/* Zero EFLAGS */
|
|
|
|
|
pushq $0
|
|
|
|
|
popfq
|
|
|
|
|
|
2009-05-08 22:59:13 +00:00
|
|
|
/*
|
|
|
|
|
* Copy the compressed kernel to the end of our buffer
|
2007-05-02 17:27:07 +00:00
|
|
|
* where decompression in place becomes safe.
|
|
|
|
|
*/
|
2009-05-08 23:45:15 +00:00
|
|
|
pushq %rsi
|
|
|
|
|
leaq (_bss-8)(%rip), %rsi
|
|
|
|
|
leaq (_bss-8)(%rbx), %rdi
|
2009-05-08 23:20:34 +00:00
|
|
|
movq $_bss /* - $startup_32 */, %rcx
|
2009-05-08 23:45:15 +00:00
|
|
|
shrq $3, %rcx
|
|
|
|
|
std
|
|
|
|
|
rep movsq
|
|
|
|
|
cld
|
|
|
|
|
popq %rsi
|
2007-05-02 17:27:07 +00:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Jump to the relocated address.
|
|
|
|
|
*/
|
|
|
|
|
leaq relocated(%rbx), %rax
|
|
|
|
|
jmp *%rax
|
|
|
|
|
|
x86/efi: Firmware agnostic handover entry points
The EFI handover code only works if the "bitness" of the firmware and
the kernel match, i.e. 64-bit firmware and 64-bit kernel - it is not
possible to mix the two. This goes against the tradition that a 32-bit
kernel can be loaded on a 64-bit BIOS platform without having to do
anything special in the boot loader. Linux distributions, for one thing,
regularly run only 32-bit kernels on their live media.
Despite having only one 'handover_offset' field in the kernel header,
EFI boot loaders use two separate entry points to enter the kernel based
on the architecture the boot loader was compiled for,
(1) 32-bit loader: handover_offset
(2) 64-bit loader: handover_offset + 512
Since we already have two entry points, we can leverage them to infer
the bitness of the firmware we're running on, without requiring any boot
loader modifications, by making (1) and (2) valid entry points for both
CONFIG_X86_32 and CONFIG_X86_64 kernels.
To be clear, a 32-bit boot loader will always use (1) and a 64-bit boot
loader will always use (2). It's just that, if a single kernel image
supports (1) and (2) that image can be used with both 32-bit and 64-bit
boot loaders, and hence both 32-bit and 64-bit EFI.
(1) and (2) must be 512 bytes apart at all times, but that is already
part of the boot ABI and we could never change that delta without
breaking existing boot loaders anyhow.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-01-10 15:54:31 +00:00
|
|
|
#ifdef CONFIG_EFI_STUB
|
2017-08-24 07:33:27 +00:00
|
|
|
|
|
|
|
|
/* The entry point for the PE/COFF executable is efi_pe_entry. */
|
|
|
|
|
ENTRY(efi_pe_entry)
|
|
|
|
|
movq %rcx, efi64_config(%rip) /* Handle */
|
|
|
|
|
movq %rdx, efi64_config+8(%rip) /* EFI System table pointer */
|
|
|
|
|
|
|
|
|
|
leaq efi64_config(%rip), %rax
|
|
|
|
|
movq %rax, efi_config(%rip)
|
|
|
|
|
|
|
|
|
|
call 1f
|
|
|
|
|
1: popq %rbp
|
|
|
|
|
subq $1b, %rbp
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Relocate efi_config->call().
|
|
|
|
|
*/
|
|
|
|
|
addq %rbp, efi64_config+40(%rip)
|
|
|
|
|
|
|
|
|
|
movq %rax, %rdi
|
|
|
|
|
call make_boot_params
|
|
|
|
|
cmpq $0,%rax
|
|
|
|
|
je fail
|
|
|
|
|
mov %rax, %rsi
|
|
|
|
|
leaq startup_32(%rip), %rax
|
|
|
|
|
movl %eax, BP_code32_start(%rsi)
|
|
|
|
|
jmp 2f /* Skip the relocation */
|
|
|
|
|
|
|
|
|
|
handover_entry:
|
|
|
|
|
call 1f
|
|
|
|
|
1: popq %rbp
|
|
|
|
|
subq $1b, %rbp
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Relocate efi_config->call().
|
|
|
|
|
*/
|
|
|
|
|
movq efi_config(%rip), %rax
|
|
|
|
|
addq %rbp, 40(%rax)
|
|
|
|
|
2:
|
|
|
|
|
movq efi_config(%rip), %rdi
|
|
|
|
|
call efi_main
|
|
|
|
|
movq %rax,%rsi
|
|
|
|
|
cmpq $0,%rax
|
|
|
|
|
jne 2f
|
|
|
|
|
fail:
|
|
|
|
|
/* EFI init failed, so hang. */
|
|
|
|
|
hlt
|
|
|
|
|
jmp fail
|
|
|
|
|
2:
|
|
|
|
|
movl BP_code32_start(%esi), %eax
|
|
|
|
|
leaq startup_64(%rax), %rax
|
|
|
|
|
jmp *%rax
|
|
|
|
|
ENDPROC(efi_pe_entry)
|
|
|
|
|
|
x86/efi: Firmware agnostic handover entry points
The EFI handover code only works if the "bitness" of the firmware and
the kernel match, i.e. 64-bit firmware and 64-bit kernel - it is not
possible to mix the two. This goes against the tradition that a 32-bit
kernel can be loaded on a 64-bit BIOS platform without having to do
anything special in the boot loader. Linux distributions, for one thing,
regularly run only 32-bit kernels on their live media.
Despite having only one 'handover_offset' field in the kernel header,
EFI boot loaders use two separate entry points to enter the kernel based
on the architecture the boot loader was compiled for,
(1) 32-bit loader: handover_offset
(2) 64-bit loader: handover_offset + 512
Since we already have two entry points, we can leverage them to infer
the bitness of the firmware we're running on, without requiring any boot
loader modifications, by making (1) and (2) valid entry points for both
CONFIG_X86_32 and CONFIG_X86_64 kernels.
To be clear, a 32-bit boot loader will always use (1) and a 64-bit boot
loader will always use (2). It's just that, if a single kernel image
supports (1) and (2) that image can be used with both 32-bit and 64-bit
boot loaders, and hence both 32-bit and 64-bit EFI.
(1) and (2) must be 512 bytes apart at all times, but that is already
part of the boot ABI and we could never change that delta without
breaking existing boot loaders anyhow.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-01-10 15:54:31 +00:00
|
|
|
.org 0x390
|
|
|
|
|
ENTRY(efi64_stub_entry)
|
|
|
|
|
movq %rdi, efi64_config(%rip) /* Handle */
|
|
|
|
|
movq %rsi, efi64_config+8(%rip) /* EFI System table pointer */
|
|
|
|
|
|
|
|
|
|
leaq efi64_config(%rip), %rax
|
|
|
|
|
movq %rax, efi_config(%rip)
|
|
|
|
|
|
|
|
|
|
movq %rdx, %rsi
|
|
|
|
|
jmp handover_entry
|
|
|
|
|
ENDPROC(efi64_stub_entry)
|
|
|
|
|
#endif
|
|
|
|
|
|
2009-05-08 22:59:13 +00:00
|
|
|
.text
|
2007-05-02 17:27:07 +00:00
|
|
|
relocated:
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
/*
|
2009-05-08 23:27:41 +00:00
|
|
|
* Clear BSS (stack is currently empty)
|
2005-04-16 22:20:36 +00:00
|
|
|
*/
|
2009-05-08 23:45:15 +00:00
|
|
|
xorl %eax, %eax
|
|
|
|
|
leaq _bss(%rip), %rdi
|
|
|
|
|
leaq _ebss(%rip), %rcx
|
2007-05-02 17:27:07 +00:00
|
|
|
subq %rdi, %rcx
|
2009-05-08 23:45:15 +00:00
|
|
|
shrq $3, %rcx
|
|
|
|
|
rep stosq
|
2007-05-02 17:27:07 +00:00
|
|
|
|
2014-09-23 06:05:49 +00:00
|
|
|
/*
|
|
|
|
|
* Adjust our own GOT
|
|
|
|
|
*/
|
|
|
|
|
leaq _got(%rip), %rdx
|
|
|
|
|
leaq _egot(%rip), %rcx
|
|
|
|
|
1:
|
|
|
|
|
cmpq %rcx, %rdx
|
|
|
|
|
jae 2f
|
|
|
|
|
addq %rbx, (%rdx)
|
|
|
|
|
addq $8, %rdx
|
|
|
|
|
jmp 1b
|
|
|
|
|
2:
|
|
|
|
|
|
2005-04-16 22:20:36 +00:00
|
|
|
/*
|
2016-04-18 16:42:13 +00:00
|
|
|
* Do the extraction, and jump to the new kernel..
|
2005-04-16 22:20:36 +00:00
|
|
|
*/
|
2009-05-09 00:42:16 +00:00
|
|
|
pushq %rsi /* Save the real mode argument */
|
|
|
|
|
movq %rsi, %rdi /* real mode address */
|
|
|
|
|
leaq boot_heap(%rip), %rsi /* malloc area for uncompression */
|
|
|
|
|
leaq input_data(%rip), %rdx /* input_data */
|
|
|
|
|
movl $z_input_len, %ecx /* input_len */
|
|
|
|
|
movq %rbp, %r8 /* output target address */
|
2014-10-31 13:40:38 +00:00
|
|
|
movq $z_output_len, %r9 /* decompressed length, end of relocs */
|
2016-04-18 16:42:13 +00:00
|
|
|
call extract_kernel /* returns kernel location in %rax */
|
2007-05-02 17:27:07 +00:00
|
|
|
popq %rsi
|
2005-04-16 22:20:36 +00:00
|
|
|
|
|
|
|
|
/*
|
2007-05-02 17:27:07 +00:00
|
|
|
* Jump to the decompressed kernel.
|
2005-04-16 22:20:36 +00:00
|
|
|
*/
|
2013-10-11 00:18:14 +00:00
|
|
|
jmp *%rax
|
2005-04-16 22:20:36 +00:00
|
|
|
|
2013-01-24 20:20:00 +00:00
|
|
|
.code32
|
2017-06-06 11:31:25 +00:00
|
|
|
compatible_mode:
|
|
|
|
|
/* Setup data and stack segments */
|
|
|
|
|
movl $__KERNEL_DS, %eax
|
|
|
|
|
movl %eax, %ds
|
|
|
|
|
movl %eax, %ss
|
|
|
|
|
|
|
|
|
|
/* Disable paging */
|
|
|
|
|
movl %cr0, %eax
|
|
|
|
|
btrl $X86_CR0_PG_BIT, %eax
|
|
|
|
|
movl %eax, %cr0
|
|
|
|
|
|
|
|
|
|
/* Point CR3 to 5-level paging */
|
|
|
|
|
leal lvl5_pgtable(%ebx), %eax
|
|
|
|
|
movl %eax, %cr3
|
|
|
|
|
|
|
|
|
|
/* Enable PAE and LA57 mode */
|
|
|
|
|
movl %cr4, %eax
|
|
|
|
|
orl $(X86_CR4_PAE | X86_CR4_LA57), %eax
|
|
|
|
|
movl %eax, %cr4
|
|
|
|
|
|
|
|
|
|
/* Calculate address we are running at */
|
|
|
|
|
call 1f
|
|
|
|
|
1: popl %edi
|
|
|
|
|
subl $1b, %edi
|
|
|
|
|
|
|
|
|
|
/* Prepare stack for far return to Long Mode */
|
|
|
|
|
pushl $__KERNEL_CS
|
|
|
|
|
leal lvl5(%edi), %eax
|
|
|
|
|
push %eax
|
|
|
|
|
|
|
|
|
|
/* Enable paging back */
|
|
|
|
|
movl $(X86_CR0_PG | X86_CR0_PE), %eax
|
|
|
|
|
movl %eax, %cr0
|
|
|
|
|
|
|
|
|
|
lret
|
|
|
|
|
|
2013-01-24 20:20:00 +00:00
|
|
|
no_longmode:
|
|
|
|
|
/* This isn't an x86-64 CPU so hang */
|
|
|
|
|
1:
|
|
|
|
|
hlt
|
|
|
|
|
jmp 1b
|
|
|
|
|
|
|
|
|
|
#include "../../kernel/verify_cpu.S"
|
|
|
|
|
|
2007-05-02 17:27:07 +00:00
|
|
|
.data
|
|
|
|
|
gdt:
|
|
|
|
|
.word gdt_end - gdt
|
|
|
|
|
.long gdt
|
|
|
|
|
.word 0
|
2017-06-06 11:31:25 +00:00
|
|
|
.quad 0x00cf9a000000ffff /* __KERNEL32_CS */
|
2007-05-02 17:27:07 +00:00
|
|
|
.quad 0x00af9a000000ffff /* __KERNEL_CS */
|
|
|
|
|
.quad 0x00cf92000000ffff /* __KERNEL_DS */
|
2007-08-10 20:31:05 +00:00
|
|
|
.quad 0x0080890000000000 /* TS descriptor */
|
|
|
|
|
.quad 0x0000000000000000 /* TS continued */
|
2007-05-02 17:27:07 +00:00
|
|
|
gdt_end:
|
2008-04-08 10:54:30 +00:00
|
|
|
|
2014-03-05 10:15:55 +00:00
|
|
|
#ifdef CONFIG_EFI_STUB
|
2014-01-10 15:27:14 +00:00
|
|
|
efi_config:
|
|
|
|
|
.quad 0
|
|
|
|
|
|
x86/efi: Firmware agnostic handover entry points
The EFI handover code only works if the "bitness" of the firmware and
the kernel match, i.e. 64-bit firmware and 64-bit kernel - it is not
possible to mix the two. This goes against the tradition that a 32-bit
kernel can be loaded on a 64-bit BIOS platform without having to do
anything special in the boot loader. Linux distributions, for one thing,
regularly run only 32-bit kernels on their live media.
Despite having only one 'handover_offset' field in the kernel header,
EFI boot loaders use two separate entry points to enter the kernel based
on the architecture the boot loader was compiled for,
(1) 32-bit loader: handover_offset
(2) 64-bit loader: handover_offset + 512
Since we already have two entry points, we can leverage them to infer
the bitness of the firmware we're running on, without requiring any boot
loader modifications, by making (1) and (2) valid entry points for both
CONFIG_X86_32 and CONFIG_X86_64 kernels.
To be clear, a 32-bit boot loader will always use (1) and a 64-bit boot
loader will always use (2). It's just that, if a single kernel image
supports (1) and (2) that image can be used with both 32-bit and 64-bit
boot loaders, and hence both 32-bit and 64-bit EFI.
(1) and (2) must be 512 bytes apart at all times, but that is already
part of the boot ABI and we could never change that delta without
breaking existing boot loaders anyhow.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-01-10 15:54:31 +00:00
|
|
|
#ifdef CONFIG_EFI_MIXED
|
|
|
|
|
.global efi32_config
|
|
|
|
|
efi32_config:
|
2017-02-06 11:22:40 +00:00
|
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.fill 5,8,0
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x86/efi: Firmware agnostic handover entry points
The EFI handover code only works if the "bitness" of the firmware and
the kernel match, i.e. 64-bit firmware and 64-bit kernel - it is not
possible to mix the two. This goes against the tradition that a 32-bit
kernel can be loaded on a 64-bit BIOS platform without having to do
anything special in the boot loader. Linux distributions, for one thing,
regularly run only 32-bit kernels on their live media.
Despite having only one 'handover_offset' field in the kernel header,
EFI boot loaders use two separate entry points to enter the kernel based
on the architecture the boot loader was compiled for,
(1) 32-bit loader: handover_offset
(2) 64-bit loader: handover_offset + 512
Since we already have two entry points, we can leverage them to infer
the bitness of the firmware we're running on, without requiring any boot
loader modifications, by making (1) and (2) valid entry points for both
CONFIG_X86_32 and CONFIG_X86_64 kernels.
To be clear, a 32-bit boot loader will always use (1) and a 64-bit boot
loader will always use (2). It's just that, if a single kernel image
supports (1) and (2) that image can be used with both 32-bit and 64-bit
boot loaders, and hence both 32-bit and 64-bit EFI.
(1) and (2) must be 512 bytes apart at all times, but that is already
part of the boot ABI and we could never change that delta without
breaking existing boot loaders anyhow.
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
2014-01-10 15:54:31 +00:00
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.quad efi64_thunk
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.byte 0
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#endif
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2014-01-10 15:27:14 +00:00
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.global efi64_config
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efi64_config:
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2017-02-06 11:22:40 +00:00
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.fill 5,8,0
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2014-03-27 22:10:39 +00:00
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.quad efi_call
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2014-01-10 15:27:14 +00:00
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.byte 1
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2014-03-05 10:15:55 +00:00
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#endif /* CONFIG_EFI_STUB */
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2009-05-08 22:59:13 +00:00
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/*
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* Stack and heap for uncompression
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*/
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.bss
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.balign 4
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2008-04-08 10:54:30 +00:00
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boot_heap:
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.fill BOOT_HEAP_SIZE, 1, 0
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boot_stack:
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.fill BOOT_STACK_SIZE, 1, 0
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boot_stack_end:
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2009-05-08 23:20:34 +00:00
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/*
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* Space for page tables (not in .bss so not zeroed)
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*/
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.section ".pgtable","a",@nobits
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.balign 4096
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pgtable:
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x86/KASLR: Build identity mappings on demand
Currently KASLR only supports relocation in a small physical range (from
16M to 1G), due to using the initial kernel page table identity mapping.
To support ranges above this, we need to have an identity mapping for the
desired memory range before we can decompress (and later run) the kernel.
32-bit kernels already have the needed identity mapping. This patch adds
identity mappings for the needed memory ranges on 64-bit kernels. This
happens in two possible boot paths:
If loaded via startup_32(), we need to set up the needed identity map.
If loaded from a 64-bit bootloader, the bootloader will have already
set up an identity mapping, and we'll start via the compressed kernel's
startup_64(). In this case, the bootloader's page tables need to be
avoided while selecting the new uncompressed kernel location. If not,
the decompressor could overwrite them during decompression.
To accomplish this, we could walk the pagetable and find every page
that is used, and add them to mem_avoid, but this needs extra code and
will require increasing the size of the mem_avoid array.
Instead, we can create a new set of page tables for our own identity
mapping instead. The pages for the new page table will come from the
_pagetable section of the compressed kernel, which means they are
already contained by in mem_avoid array. To do this, we reuse the code
from the uncompressed kernel's identity mapping routines.
The _pgtable will be shared by both the 32-bit and 64-bit paths to reduce
init_size, as now the compressed kernel's _rodata to _end will contribute
to init_size.
To handle the possible mappings, we need to increase the existing page
table buffer size:
When booting via startup_64(), we need to cover the old VO, params,
cmdline and uncompressed kernel. In an extreme case we could have them
all beyond the 512G boundary, which needs (2+2)*4 pages with 2M mappings.
And we'll need 2 for first 2M for VGA RAM. One more is needed for level4.
This gets us to 19 pages total.
When booting via startup_32(), KASLR could move the uncompressed kernel
above 4G, so we need to create extra identity mappings, which should only
need (2+2) pages at most when it is beyond the 512G boundary. So 19
pages is sufficient for this case as well.
The resulting BOOT_*PGT_SIZE defines use the "_SIZE" suffix on their
names to maintain logical consistency with the existing BOOT_HEAP_SIZE
and BOOT_STACK_SIZE defines.
This patch is based on earlier patches from Yinghai Lu and Baoquan He.
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: kernel-hardening@lists.openwall.com
Cc: lasse.collin@tukaani.org
Link: http://lkml.kernel.org/r/1462572095-11754-4-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-05-06 22:01:35 +00:00
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.fill BOOT_PGT_SIZE, 1, 0
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2017-06-06 11:31:25 +00:00
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lvl5_pgtable:
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.fill PAGE_SIZE, 1, 0
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