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 15:07:57 +01:00
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// SPDX-License-Identifier: GPL-2.0
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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 15:01:35 -07:00
|
|
|
/*
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|
* This code is used on x86_64 to create page table identity mappings on
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* demand by building up a new set of page tables (or appending to the
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|
* existing ones), and then switching over to them when ready.
|
2016-05-25 15:45:31 -07:00
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*
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* Copyright (C) 2015-2016 Yinghai Lu
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|
* Copyright (C) 2016 Kees Cook
|
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 15:01:35 -07:00
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*/
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2023-11-21 08:07:31 -08:00
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/* No MITIGATION_PAGE_TABLE_ISOLATION support needed either: */
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#undef CONFIG_MITIGATION_PAGE_TABLE_ISOLATION
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2017-12-04 15:07:36 +01:00
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2020-09-07 15:15:16 +02:00
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#include "error.h"
|
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 15:01:35 -07:00
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#include "misc.h"
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/* These actually do the work of building the kernel identity maps. */
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2020-06-08 21:32:38 -07:00
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#include <linux/pgtable.h>
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2020-09-07 15:15:23 +02:00
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#include <asm/cmpxchg.h>
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2020-09-07 15:15:16 +02:00
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#include <asm/trap_pf.h>
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#include <asm/trapnr.h>
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2020-06-08 21:32:42 -07:00
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#include <asm/init.h>
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2016-06-21 17:47:03 -07:00
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/* Use the static base for this part of the boot process */
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#undef __PAGE_OFFSET
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#define __PAGE_OFFSET __PAGE_OFFSET_BASE
|
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 15:01:35 -07:00
|
|
|
#include "../../mm/ident_map.c"
|
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2020-10-16 16:04:01 -04:00
|
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#define _SETUP
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#include <asm/setup.h> /* For COMMAND_LINE_SIZE */
|
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#undef _SETUP
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extern unsigned long get_cmd_line_ptr(void);
|
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2020-09-07 15:15:15 +02:00
|
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|
/* Used by PAGE_KERN* macros: */
|
|
|
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|
pteval_t __default_kernel_pte_mask __read_mostly = ~0;
|
|
|
|
|
|
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 15:01:35 -07:00
|
|
|
/* Used to track our page table allocation area. */
|
|
|
|
|
struct alloc_pgt_data {
|
|
|
|
|
unsigned char *pgt_buf;
|
|
|
|
|
unsigned long pgt_buf_size;
|
|
|
|
|
unsigned long pgt_buf_offset;
|
|
|
|
|
};
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Allocates space for a page table entry, using struct alloc_pgt_data
|
|
|
|
|
* above. Besides the local callers, this is used as the allocation
|
|
|
|
|
* callback in mapping_info below.
|
|
|
|
|
*/
|
|
|
|
|
static void *alloc_pgt_page(void *context)
|
|
|
|
|
{
|
|
|
|
|
struct alloc_pgt_data *pages = (struct alloc_pgt_data *)context;
|
|
|
|
|
unsigned char *entry;
|
|
|
|
|
|
|
|
|
|
/* Validate there is space available for a new page. */
|
|
|
|
|
if (pages->pgt_buf_offset >= pages->pgt_buf_size) {
|
|
|
|
|
debug_putstr("out of pgt_buf in " __FILE__ "!?\n");
|
|
|
|
|
debug_putaddr(pages->pgt_buf_offset);
|
|
|
|
|
debug_putaddr(pages->pgt_buf_size);
|
|
|
|
|
return NULL;
|
|
|
|
|
}
|
|
|
|
|
|
2023-09-15 10:02:21 +03:00
|
|
|
/* Consumed more tables than expected? */
|
|
|
|
|
if (pages->pgt_buf_offset == BOOT_PGT_SIZE_WARN) {
|
|
|
|
|
debug_putstr("pgt_buf running low in " __FILE__ "\n");
|
|
|
|
|
debug_putstr("Need to raise BOOT_PGT_SIZE?\n");
|
|
|
|
|
debug_putaddr(pages->pgt_buf_offset);
|
|
|
|
|
debug_putaddr(pages->pgt_buf_size);
|
|
|
|
|
}
|
|
|
|
|
|
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 15:01:35 -07:00
|
|
|
entry = pages->pgt_buf + pages->pgt_buf_offset;
|
|
|
|
|
pages->pgt_buf_offset += PAGE_SIZE;
|
|
|
|
|
|
|
|
|
|
return entry;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* Used to track our allocated page tables. */
|
|
|
|
|
static struct alloc_pgt_data pgt_data;
|
|
|
|
|
|
|
|
|
|
/* The top level page table entry pointer. */
|
2017-06-28 15:17:30 +03:00
|
|
|
static unsigned long top_level_pgt;
|
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 15:01:35 -07:00
|
|
|
|
2018-05-18 14:30:28 +03:00
|
|
|
phys_addr_t physical_mask = (1ULL << __PHYSICAL_MASK_SHIFT) - 1;
|
|
|
|
|
|
2016-05-25 15:45:31 -07:00
|
|
|
/*
|
|
|
|
|
* Mapping information structure passed to kernel_ident_mapping_init().
|
|
|
|
|
* Due to relocation, pointers must be assigned at run time not build time.
|
|
|
|
|
*/
|
2017-10-20 09:30:54 -05:00
|
|
|
static struct x86_mapping_info mapping_info;
|
2016-05-25 15:45:31 -07:00
|
|
|
|
2020-09-07 15:15:17 +02:00
|
|
|
/*
|
2020-09-07 15:15:18 +02:00
|
|
|
* Adds the specified range to the identity mappings.
|
2020-09-07 15:15:17 +02:00
|
|
|
*/
|
2022-02-24 10:56:16 -06:00
|
|
|
void kernel_add_identity_map(unsigned long start, unsigned long end)
|
2020-09-07 15:15:17 +02:00
|
|
|
{
|
2020-09-07 15:15:22 +02:00
|
|
|
int ret;
|
|
|
|
|
|
2020-09-07 15:15:17 +02:00
|
|
|
/* Align boundary to 2M. */
|
|
|
|
|
start = round_down(start, PMD_SIZE);
|
|
|
|
|
end = round_up(end, PMD_SIZE);
|
|
|
|
|
if (start >= end)
|
|
|
|
|
return;
|
|
|
|
|
|
|
|
|
|
/* Build the mapping. */
|
2020-09-07 15:15:22 +02:00
|
|
|
ret = kernel_ident_mapping_init(&mapping_info, (pgd_t *)top_level_pgt, start, end);
|
|
|
|
|
if (ret)
|
|
|
|
|
error("Error: kernel_ident_mapping_init() failed\n");
|
2020-09-07 15:15:17 +02:00
|
|
|
}
|
|
|
|
|
|
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 15:01:35 -07:00
|
|
|
/* Locates and clears a region for a new top level page table. */
|
2020-10-16 16:04:01 -04:00
|
|
|
void initialize_identity_maps(void *rmode)
|
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 15:01:35 -07:00
|
|
|
{
|
2020-10-16 16:04:01 -04:00
|
|
|
unsigned long cmdline;
|
2022-07-05 21:53:15 -05:00
|
|
|
struct setup_data *sd;
|
2020-10-16 16:04:01 -04:00
|
|
|
|
2018-05-18 14:30:28 +03:00
|
|
|
/* Exclude the encryption mask from __PHYSICAL_MASK */
|
|
|
|
|
physical_mask &= ~sme_me_mask;
|
|
|
|
|
|
2016-05-25 15:45:31 -07:00
|
|
|
/* Init mapping_info with run-time function/buffer pointers. */
|
|
|
|
|
mapping_info.alloc_pgt_page = alloc_pgt_page;
|
|
|
|
|
mapping_info.context = &pgt_data;
|
2018-03-27 17:07:11 -05:00
|
|
|
mapping_info.page_flag = __PAGE_KERNEL_LARGE_EXEC | sme_me_mask;
|
|
|
|
|
mapping_info.kernpg_flag = _KERNPG_TABLE;
|
2016-05-25 15:45:31 -07:00
|
|
|
|
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 15:01:35 -07:00
|
|
|
/*
|
|
|
|
|
* It should be impossible for this not to already be true,
|
|
|
|
|
* but since calling this a second time would rewind the other
|
|
|
|
|
* counters, let's just make sure this is reset too.
|
|
|
|
|
*/
|
|
|
|
|
pgt_data.pgt_buf_offset = 0;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* If we came here via startup_32(), cr3 will be _pgtable already
|
|
|
|
|
* and we must append to the existing area instead of entirely
|
|
|
|
|
* overwriting it.
|
2017-06-28 15:17:30 +03:00
|
|
|
*
|
|
|
|
|
* With 5-level paging, we use '_pgtable' to allocate the p4d page table,
|
|
|
|
|
* the top-level page table is allocated separately.
|
|
|
|
|
*
|
|
|
|
|
* p4d_offset(top_level_pgt, 0) would cover both the 4- and 5-level
|
|
|
|
|
* cases. On 4-level paging it's equal to 'top_level_pgt'.
|
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 15:01:35 -07:00
|
|
|
*/
|
2017-06-28 15:17:30 +03:00
|
|
|
top_level_pgt = read_cr3_pa();
|
|
|
|
|
if (p4d_offset((pgd_t *)top_level_pgt, 0) == (p4d_t *)_pgtable) {
|
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 15:01:35 -07:00
|
|
|
pgt_data.pgt_buf = _pgtable + BOOT_INIT_PGT_SIZE;
|
|
|
|
|
pgt_data.pgt_buf_size = BOOT_PGT_SIZE - BOOT_INIT_PGT_SIZE;
|
|
|
|
|
memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size);
|
|
|
|
|
} else {
|
|
|
|
|
pgt_data.pgt_buf = _pgtable;
|
|
|
|
|
pgt_data.pgt_buf_size = BOOT_PGT_SIZE;
|
|
|
|
|
memset(pgt_data.pgt_buf, 0, pgt_data.pgt_buf_size);
|
2017-06-28 15:17:30 +03:00
|
|
|
top_level_pgt = (unsigned long)alloc_pgt_page(&pgt_data);
|
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 15:01:35 -07:00
|
|
|
}
|
|
|
|
|
|
2020-09-07 15:15:17 +02:00
|
|
|
/*
|
2020-10-16 16:04:01 -04:00
|
|
|
* New page-table is set up - map the kernel image, boot_params and the
|
|
|
|
|
* command line. The uncompressed kernel requires boot_params and the
|
|
|
|
|
* command line to be mapped in the identity mapping. Map them
|
|
|
|
|
* explicitly here in case the compressed kernel does not touch them,
|
|
|
|
|
* or does not touch all the pages covering them.
|
2020-09-07 15:15:17 +02:00
|
|
|
*/
|
2022-02-24 10:56:16 -06:00
|
|
|
kernel_add_identity_map((unsigned long)_head, (unsigned long)_end);
|
x86/boot: Rename conflicting 'boot_params' pointer to 'boot_params_ptr'
The x86 decompressor is built and linked as a separate executable, but
it shares components with the kernel proper, which are either #include'd
as C files, or linked into the decompresor as a static library (e.g, the
EFI stub)
Both the kernel itself and the decompressor define a global symbol
'boot_params' to refer to the boot_params struct, but in the former
case, it refers to the struct directly, whereas in the decompressor, it
refers to a global pointer variable referring to the struct boot_params
passed by the bootloader or constructed from scratch.
This ambiguity is unfortunate, and makes it impossible to assign this
decompressor variable from the x86 EFI stub, given that declaring it as
extern results in a clash. So rename the decompressor version (whose
scope is limited) to boot_params_ptr.
[ mingo: Renamed 'boot_params_p' to 'boot_params_ptr' for clarity ]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
2023-10-17 15:25:12 +02:00
|
|
|
boot_params_ptr = rmode;
|
|
|
|
|
kernel_add_identity_map((unsigned long)boot_params_ptr,
|
|
|
|
|
(unsigned long)(boot_params_ptr + 1));
|
2020-10-16 16:04:01 -04:00
|
|
|
cmdline = get_cmd_line_ptr();
|
2022-02-24 10:56:16 -06:00
|
|
|
kernel_add_identity_map(cmdline, cmdline + COMMAND_LINE_SIZE);
|
2020-10-16 16:04:01 -04:00
|
|
|
|
2022-07-05 21:53:15 -05:00
|
|
|
/*
|
|
|
|
|
* Also map the setup_data entries passed via boot_params in case they
|
|
|
|
|
* need to be accessed by uncompressed kernel via the identity mapping.
|
|
|
|
|
*/
|
x86/boot: Rename conflicting 'boot_params' pointer to 'boot_params_ptr'
The x86 decompressor is built and linked as a separate executable, but
it shares components with the kernel proper, which are either #include'd
as C files, or linked into the decompresor as a static library (e.g, the
EFI stub)
Both the kernel itself and the decompressor define a global symbol
'boot_params' to refer to the boot_params struct, but in the former
case, it refers to the struct directly, whereas in the decompressor, it
refers to a global pointer variable referring to the struct boot_params
passed by the bootloader or constructed from scratch.
This ambiguity is unfortunate, and makes it impossible to assign this
decompressor variable from the x86 EFI stub, given that declaring it as
extern results in a clash. So rename the decompressor version (whose
scope is limited) to boot_params_ptr.
[ mingo: Renamed 'boot_params_p' to 'boot_params_ptr' for clarity ]
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: linux-kernel@vger.kernel.org
2023-10-17 15:25:12 +02:00
|
|
|
sd = (struct setup_data *)boot_params_ptr->hdr.setup_data;
|
2022-07-05 21:53:15 -05:00
|
|
|
while (sd) {
|
|
|
|
|
unsigned long sd_addr = (unsigned long)sd;
|
|
|
|
|
|
|
|
|
|
kernel_add_identity_map(sd_addr, sd_addr + sizeof(*sd) + sd->len);
|
|
|
|
|
sd = (struct setup_data *)sd->next;
|
|
|
|
|
}
|
|
|
|
|
|
2022-02-24 10:56:17 -06:00
|
|
|
sev_prep_identity_maps(top_level_pgt);
|
|
|
|
|
|
2020-10-16 16:04:01 -04:00
|
|
|
/* Load the new page-table. */
|
2020-09-07 15:15:17 +02:00
|
|
|
write_cr3(top_level_pgt);
|
2023-01-18 11:49:43 +05:30
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Now that the required page table mappings are established and a
|
|
|
|
|
* GHCB can be used, check for SNP guest/HV feature compatibility.
|
|
|
|
|
*/
|
|
|
|
|
snp_check_features();
|
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 15:01:35 -07:00
|
|
|
}
|
|
|
|
|
|
2020-09-07 15:15:23 +02:00
|
|
|
static pte_t *split_large_pmd(struct x86_mapping_info *info,
|
|
|
|
|
pmd_t *pmdp, unsigned long __address)
|
|
|
|
|
{
|
|
|
|
|
unsigned long page_flags;
|
|
|
|
|
unsigned long address;
|
|
|
|
|
pte_t *pte;
|
|
|
|
|
pmd_t pmd;
|
|
|
|
|
int i;
|
|
|
|
|
|
|
|
|
|
pte = (pte_t *)info->alloc_pgt_page(info->context);
|
|
|
|
|
if (!pte)
|
|
|
|
|
return NULL;
|
|
|
|
|
|
|
|
|
|
address = __address & PMD_MASK;
|
|
|
|
|
/* No large page - clear PSE flag */
|
|
|
|
|
page_flags = info->page_flag & ~_PAGE_PSE;
|
|
|
|
|
|
|
|
|
|
/* Populate the PTEs */
|
|
|
|
|
for (i = 0; i < PTRS_PER_PMD; i++) {
|
|
|
|
|
set_pte(&pte[i], __pte(address | page_flags));
|
|
|
|
|
address += PAGE_SIZE;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Ideally we need to clear the large PMD first and do a TLB
|
|
|
|
|
* flush before we write the new PMD. But the 2M range of the
|
|
|
|
|
* PMD might contain the code we execute and/or the stack
|
|
|
|
|
* we are on, so we can't do that. But that should be safe here
|
|
|
|
|
* because we are going from large to small mappings and we are
|
|
|
|
|
* also the only user of the page-table, so there is no chance
|
|
|
|
|
* of a TLB multihit.
|
|
|
|
|
*/
|
|
|
|
|
pmd = __pmd((unsigned long)pte | info->kernpg_flag);
|
|
|
|
|
set_pmd(pmdp, pmd);
|
|
|
|
|
/* Flush TLB to establish the new PMD */
|
|
|
|
|
write_cr3(top_level_pgt);
|
|
|
|
|
|
|
|
|
|
return pte + pte_index(__address);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static void clflush_page(unsigned long address)
|
|
|
|
|
{
|
|
|
|
|
unsigned int flush_size;
|
|
|
|
|
char *cl, *start, *end;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Hardcode cl-size to 64 - CPUID can't be used here because that might
|
|
|
|
|
* cause another #VC exception and the GHCB is not ready to use yet.
|
|
|
|
|
*/
|
|
|
|
|
flush_size = 64;
|
|
|
|
|
start = (char *)(address & PAGE_MASK);
|
|
|
|
|
end = start + PAGE_SIZE;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* First make sure there are no pending writes on the cache-lines to
|
|
|
|
|
* flush.
|
|
|
|
|
*/
|
|
|
|
|
asm volatile("mfence" : : : "memory");
|
|
|
|
|
|
|
|
|
|
for (cl = start; cl != end; cl += flush_size)
|
|
|
|
|
clflush(cl);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
static int set_clr_page_flags(struct x86_mapping_info *info,
|
|
|
|
|
unsigned long address,
|
|
|
|
|
pteval_t set, pteval_t clr)
|
|
|
|
|
{
|
|
|
|
|
pgd_t *pgdp = (pgd_t *)top_level_pgt;
|
|
|
|
|
p4d_t *p4dp;
|
|
|
|
|
pud_t *pudp;
|
|
|
|
|
pmd_t *pmdp;
|
|
|
|
|
pte_t *ptep, pte;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* First make sure there is a PMD mapping for 'address'.
|
|
|
|
|
* It should already exist, but keep things generic.
|
|
|
|
|
*
|
|
|
|
|
* To map the page just read from it and fault it in if there is no
|
2022-02-24 10:56:16 -06:00
|
|
|
* mapping yet. kernel_add_identity_map() can't be called here because
|
|
|
|
|
* that would unconditionally map the address on PMD level, destroying
|
|
|
|
|
* any PTE-level mappings that might already exist. Use assembly here
|
|
|
|
|
* so the access won't be optimized away.
|
2020-09-07 15:15:23 +02:00
|
|
|
*/
|
|
|
|
|
asm volatile("mov %[address], %%r9"
|
|
|
|
|
:: [address] "g" (*(unsigned long *)address)
|
|
|
|
|
: "r9", "memory");
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* The page is mapped at least with PMD size - so skip checks and walk
|
|
|
|
|
* directly to the PMD.
|
|
|
|
|
*/
|
|
|
|
|
p4dp = p4d_offset(pgdp, address);
|
|
|
|
|
pudp = pud_offset(p4dp, address);
|
|
|
|
|
pmdp = pmd_offset(pudp, address);
|
|
|
|
|
|
2024-03-05 12:37:47 +08:00
|
|
|
if (pmd_leaf(*pmdp))
|
2020-09-07 15:15:23 +02:00
|
|
|
ptep = split_large_pmd(info, pmdp, address);
|
|
|
|
|
else
|
|
|
|
|
ptep = pte_offset_kernel(pmdp, address);
|
|
|
|
|
|
|
|
|
|
if (!ptep)
|
|
|
|
|
return -ENOMEM;
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Changing encryption attributes of a page requires to flush it from
|
|
|
|
|
* the caches.
|
|
|
|
|
*/
|
2022-02-09 12:10:09 -06:00
|
|
|
if ((set | clr) & _PAGE_ENC) {
|
2020-09-07 15:15:23 +02:00
|
|
|
clflush_page(address);
|
|
|
|
|
|
2022-02-09 12:10:09 -06:00
|
|
|
/*
|
|
|
|
|
* If the encryption attribute is being cleared, change the page state
|
|
|
|
|
* to shared in the RMP table.
|
|
|
|
|
*/
|
|
|
|
|
if (clr)
|
|
|
|
|
snp_set_page_shared(__pa(address & PAGE_MASK));
|
|
|
|
|
}
|
|
|
|
|
|
2020-09-07 15:15:23 +02:00
|
|
|
/* Update PTE */
|
|
|
|
|
pte = *ptep;
|
|
|
|
|
pte = pte_set_flags(pte, set);
|
|
|
|
|
pte = pte_clear_flags(pte, clr);
|
|
|
|
|
set_pte(ptep, pte);
|
|
|
|
|
|
2022-02-09 12:10:09 -06:00
|
|
|
/*
|
|
|
|
|
* If the encryption attribute is being set, then change the page state to
|
|
|
|
|
* private in the RMP entry. The page state change must be done after the PTE
|
|
|
|
|
* is updated.
|
|
|
|
|
*/
|
|
|
|
|
if (set & _PAGE_ENC)
|
|
|
|
|
snp_set_page_private(__pa(address & PAGE_MASK));
|
|
|
|
|
|
2020-09-07 15:15:23 +02:00
|
|
|
/* Flush TLB after changing encryption attribute */
|
|
|
|
|
write_cr3(top_level_pgt);
|
|
|
|
|
|
|
|
|
|
return 0;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
int set_page_decrypted(unsigned long address)
|
|
|
|
|
{
|
|
|
|
|
return set_clr_page_flags(&mapping_info, address, 0, _PAGE_ENC);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
int set_page_encrypted(unsigned long address)
|
|
|
|
|
{
|
|
|
|
|
return set_clr_page_flags(&mapping_info, address, _PAGE_ENC, 0);
|
|
|
|
|
}
|
|
|
|
|
|
2020-09-07 15:15:25 +02:00
|
|
|
int set_page_non_present(unsigned long address)
|
|
|
|
|
{
|
|
|
|
|
return set_clr_page_flags(&mapping_info, address, 0, _PAGE_PRESENT);
|
|
|
|
|
}
|
|
|
|
|
|
2020-09-07 15:15:16 +02:00
|
|
|
static void do_pf_error(const char *msg, unsigned long error_code,
|
|
|
|
|
unsigned long address, unsigned long ip)
|
|
|
|
|
{
|
|
|
|
|
error_putstr(msg);
|
|
|
|
|
|
|
|
|
|
error_putstr("\nError Code: ");
|
|
|
|
|
error_puthex(error_code);
|
|
|
|
|
error_putstr("\nCR2: 0x");
|
|
|
|
|
error_puthex(address);
|
|
|
|
|
error_putstr("\nRIP relative to _head: 0x");
|
|
|
|
|
error_puthex(ip - (unsigned long)_head);
|
|
|
|
|
error_putstr("\n");
|
|
|
|
|
|
|
|
|
|
error("Stopping.\n");
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code)
|
|
|
|
|
{
|
2020-09-07 15:15:25 +02:00
|
|
|
unsigned long address = native_read_cr2();
|
|
|
|
|
unsigned long end;
|
|
|
|
|
bool ghcb_fault;
|
|
|
|
|
|
|
|
|
|
ghcb_fault = sev_es_check_ghcb_fault(address);
|
|
|
|
|
|
|
|
|
|
address &= PMD_MASK;
|
|
|
|
|
end = address + PMD_SIZE;
|
2020-09-07 15:15:16 +02:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Check for unexpected error codes. Unexpected are:
|
|
|
|
|
* - Faults on present pages
|
|
|
|
|
* - User faults
|
|
|
|
|
* - Reserved bits set
|
|
|
|
|
*/
|
|
|
|
|
if (error_code & (X86_PF_PROT | X86_PF_USER | X86_PF_RSVD))
|
|
|
|
|
do_pf_error("Unexpected page-fault:", error_code, address, regs->ip);
|
2020-09-07 15:15:25 +02:00
|
|
|
else if (ghcb_fault)
|
|
|
|
|
do_pf_error("Page-fault on GHCB page:", error_code, address, regs->ip);
|
2020-09-07 15:15:16 +02:00
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* Error code is sane - now identity map the 2M region around
|
|
|
|
|
* the faulting address.
|
|
|
|
|
*/
|
2022-02-24 10:56:16 -06:00
|
|
|
kernel_add_identity_map(address, end);
|
2020-09-07 15:15:16 +02:00
|
|
|
}
|
2023-11-29 15:44:49 -05:00
|
|
|
|
|
|
|
|
void do_boot_nmi_trap(struct pt_regs *regs, unsigned long error_code)
|
|
|
|
|
{
|
2024-02-02 03:51:58 +00:00
|
|
|
spurious_nmi_count++;
|
2023-11-29 15:44:49 -05:00
|
|
|
}
|