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>
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Merge tag 'spdx_identifiers-4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull initial SPDX identifiers from Greg KH:
"License cleanup: add SPDX license identifiers to some files
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>"
* tag 'spdx_identifiers-4.14-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
License cleanup: add SPDX license identifier to uapi header files with a license
License cleanup: add SPDX license identifier to uapi header files with no license
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>
Up to this point, only fault.c used the definitions of the page fault error
codes. Thus, it made sense to keep them within such file. Other portions of
code might be interested in those definitions too. For instance, the User-
Mode Instruction Prevention emulation code will use such definitions to
emulate a page fault when it is unable to successfully copy the results
of the emulated instructions to user space.
While relocating the error code enumeration, the prefix X86_ is used to
make it consistent with the rest of the definitions in traps.h. Of course,
code using the enumeration had to be updated as well. No functional changes
were performed.
Signed-off-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: ricardo.neri@intel.com
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Huang Rui <ray.huang@amd.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: "Ravi V. Shankar" <ravi.v.shankar@intel.com>
Cc: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Chen Yucong <slaoub@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Link: https://lkml.kernel.org/r/1509135945-13762-2-git-send-email-ricardo.neri-calderon@linux.intel.com
Syzkaller with KASAN has reported a use-after-free of vma->vm_flags in
__do_page_fault() with the following reproducer:
mmap(&(0x7f0000000000/0xfff000)=nil, 0xfff000, 0x3, 0x32, 0xffffffffffffffff, 0x0)
mmap(&(0x7f0000011000/0x3000)=nil, 0x3000, 0x1, 0x32, 0xffffffffffffffff, 0x0)
r0 = userfaultfd(0x0)
ioctl$UFFDIO_API(r0, 0xc018aa3f, &(0x7f0000002000-0x18)={0xaa, 0x0, 0x0})
ioctl$UFFDIO_REGISTER(r0, 0xc020aa00, &(0x7f0000019000)={{&(0x7f0000012000/0x2000)=nil, 0x2000}, 0x1, 0x0})
r1 = gettid()
syz_open_dev$evdev(&(0x7f0000013000-0x12)="2f6465762f696e7075742f6576656e742300", 0x0, 0x0)
tkill(r1, 0x7)
The vma should be pinned by mmap_sem, but handle_userfault() might (in a
return to userspace scenario) release it and then acquire again, so when
we return to __do_page_fault() (with other result than VM_FAULT_RETRY),
the vma might be gone.
Specifically, per Andrea the scenario is
"A return to userland to repeat the page fault later with a
VM_FAULT_NOPAGE retval (potentially after handling any pending signal
during the return to userland). The return to userland is identified
whenever FAULT_FLAG_USER|FAULT_FLAG_KILLABLE are both set in
vmf->flags"
However, since commit a3c4fb7c9c ("x86/mm: Fix fault error path using
unsafe vma pointer") there is a vma_pkey() read of vma->vm_flags after
that point, which can thus become use-after-free. Fix this by moving
the read before calling handle_mm_fault().
Reported-by: syzbot <bot+6a5269ce759a7bb12754ed9622076dc93f65a1f6@syzkaller.appspotmail.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Suggested-by: Kirill A. Shutemov <kirill@shutemov.name>
Fixes: 3c4fb7c9c2e ("x86/mm: Fix fault error path using unsafe vma pointer")
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
commit 7b2d0dbac4 ("x86/mm/pkeys: Pass VMA down in to fault signal
generation code") passes down a vma pointer to the error path, but that is
done once the mmap_sem is released when calling mm_fault_error() from
__do_page_fault().
This is dangerous as the vma structure is no more safe to be used once the
mmap_sem has been released. As only the protection key value is required in
the error processing, we could just pass down this value.
Fix it by passing a pointer to a protection key value down to the fault
signal generation code. The use of a pointer allows to keep the check
generating a warning message in fill_sig_info_pkey() when the vma was not
known. If the pointer is valid, the protection value can be accessed by
deferencing the pointer.
[ tglx: Made *pkey u32 as that's the type which is passed in siginfo ]
Fixes: 7b2d0dbac4 ("x86/mm/pkeys: Pass VMA down in to fault signal generation code")
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1504513935-12742-1-git-send-email-ldufour@linux.vnet.ibm.com
For inline asm statements which have a CALL instruction, we list the
stack pointer as a constraint to convince GCC to ensure the frame
pointer is set up first:
static inline void foo()
{
register void *__sp asm(_ASM_SP);
asm("call bar" : "+r" (__sp))
}
Unfortunately, that pattern causes Clang to corrupt the stack pointer.
The fix is easy: convert the stack pointer register variable to a global
variable.
It should be noted that the end result is different based on the GCC
version. With GCC 6.4, this patch has exactly the same result as
before:
defconfig defconfig-nofp distro distro-nofp
before 9820389 9491555 8816046 8516940
after 9820389 9491555 8816046 8516940
With GCC 7.2, however, GCC's behavior has changed. It now changes its
behavior based on the conversion of the register variable to a global.
That somehow convinces it to *always* set up the frame pointer before
inserting *any* inline asm. (Therefore, listing the variable as an
output constraint is a no-op and is no longer necessary.) It's a bit
overkill, but the performance impact should be negligible. And in fact,
there's a nice improvement with frame pointers disabled:
defconfig defconfig-nofp distro distro-nofp
before 9796316 9468236 9076191 8790305
after 9796957 9464267 9076381 8785949
So in summary, while listing the stack pointer as an output constraint
is no longer necessary for newer versions of GCC, it's still needed for
older versions.
Suggested-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reported-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/3db862e970c432ae823cf515c52b54fec8270e0e.1505942196.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 apic updates from Thomas Gleixner:
"This update provides:
- Cleanup of the IDT management including the removal of the extra
tracing IDT. A first step to cleanup the vector management code.
- The removal of the paravirt op adjust_exception_frame. This is a
XEN specific issue, but merged through this branch to avoid nasty
merge collisions
- Prevent dmesg spam about the TSC DEADLINE bug, when the CPU has
disabled the TSC DEADLINE timer in CPUID.
- Adjust a debug message in the ioapic code to print out the
information correctly"
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
x86/idt: Fix the X86_TRAP_BP gate
x86/xen: Get rid of paravirt op adjust_exception_frame
x86/eisa: Add missing include
x86/idt: Remove superfluous ALIGNment
x86/apic: Silence "FW_BUG TSC_DEADLINE disabled due to Errata" on CPUs without the feature
x86/idt: Remove the tracing IDT leftovers
x86/idt: Hide set_intr_gate()
x86/idt: Simplify alloc_intr_gate()
x86/idt: Deinline setup functions
x86/idt: Remove unused functions/inlines
x86/idt: Move interrupt gate initialization to IDT code
x86/idt: Move APIC gate initialization to tables
x86/idt: Move regular trap init to tables
x86/idt: Move IST stack based traps to table init
x86/idt: Move debug stack init to table based
x86/idt: Switch early trap init to IDT tables
x86/idt: Prepare for table based init
x86/idt: Move early IDT setup out of 32-bit asm
x86/idt: Move early IDT handler setup to IDT code
x86/idt: Consolidate IDT invalidation
...
The lack of newlines in preceding format strings is a clear indication
that these were meant to be continuations of one another, and indeed
output ends up quite a bit more compact (and readable) that way.
Switch other plain printk()-s in the function instances to pr_info(),
as requested.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/59A7D72B0200007800175E4E@prv-mh.provo.novell.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The pagefault and the resched IPI handler are the only ones where it is
worth to optimize the code further in case tracepoints are disabled. But it
makes no sense to have a single static key for both.
Seperate the static keys so the facilities are handled seperately.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064957.536699116@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Make use of the new irqvector tracing static key and remove the duplicated
trace_do_pagefault() implementation.
If irq vector tracing is disabled, then the overhead of this is a single
NOP5, which is a reasonable tradeoff to avoid duplicated code and the
unholy macro mess.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064956.672965407@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The kernel has several code paths that read CR3. Most of them assume that
CR3 contains the PGD's physical address, whereas some of them awkwardly
use PHYSICAL_PAGE_MASK to mask off low bits.
Add explicit mask macros for CR3 and convert all of the CR3 readers.
This will keep them from breaking when PCID is enabled.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
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: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: xen-devel <xen-devel@lists.xen.org>
Link: http://lkml.kernel.org/r/883f8fb121f4616c1c1427ad87350bb2f5ffeca1.1497288170.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This patch only covers simple cases. Less trivial cases will be
converted with separate patches.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170313143309.16020-3-kirill.shutemov@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We are going to split <linux/sched/task_stack.h> out of <linux/sched.h>, which
will have to be picked up from other headers and a couple of .c files.
Create a trivial placeholder <linux/sched/task_stack.h> file that just
maps to <linux/sched.h> to make this patch obviously correct and
bisectable.
Include the new header in the files that are going to need it.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Since commit af2cf278ef ("x86/mm/hotplug: Don't remove PGD entries in
remove_pagetable()") there are no callers of sync_global_pgds() which set
the 'removed' argument to 1.
Remove the argument and the related conditionals in the function.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Link: http://lkml.kernel.org/r/20161214234403.137556-1-kirill.shutemov@linux.intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Printing kernel text addresses in stack dumps is of questionable value,
especially now that address randomization is becoming common.
It can be a security issue because it leaks kernel addresses. It also
affects the usefulness of the stack dump. Linus says:
"I actually spend time cleaning up commit messages in logs, because
useless data that isn't actually information (random hex numbers) is
actively detrimental.
It makes commit logs less legible.
It also makes it harder to parse dumps.
It's not useful. That makes it actively bad.
I probably look at more oops reports than most people. I have not
found the hex numbers useful for the last five years, because they are
just randomized crap.
The stack content thing just makes code scroll off the screen etc, for
example."
The only real downside to removing these addresses is that they can be
used to disambiguate duplicate symbol names. However such cases are
rare, and the context of the stack dump should be enough to be able to
figure it out.
There's now a 'faddr2line' script which can be used to convert a
function address to a file name and line:
$ ./scripts/faddr2line ~/k/vmlinux write_sysrq_trigger+0x51/0x60
write_sysrq_trigger+0x51/0x60:
write_sysrq_trigger at drivers/tty/sysrq.c:1098
Or gdb can be used:
$ echo "list *write_sysrq_trigger+0x51" |gdb ~/k/vmlinux |grep "is in"
(gdb) 0xffffffff815b5d83 is in driver_probe_device (/home/jpoimboe/git/linux/drivers/base/dd.c:378).
(But note that when there are duplicate symbol names, gdb will only show
the first symbol it finds. faddr2line is recommended over gdb because
it handles duplicates and it also does function size checking.)
Here's an example of what a stack dump looks like after this change:
BUG: unable to handle kernel NULL pointer dereference at (null)
IP: sysrq_handle_crash+0x45/0x80
PGD 36bfa067 [ 29.650644] PUD 7aca3067
Oops: 0002 [#1] PREEMPT SMP
Modules linked in: ...
CPU: 1 PID: 786 Comm: bash Tainted: G E 4.9.0-rc1+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014
task: ffff880078582a40 task.stack: ffffc90000ba8000
RIP: 0010:sysrq_handle_crash+0x45/0x80
RSP: 0018:ffffc90000babdc8 EFLAGS: 00010296
RAX: ffff880078582a40 RBX: 0000000000000063 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000292
RBP: ffffc90000babdc8 R08: 0000000b31866061 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000007 R14: ffffffff81ee8680 R15: 0000000000000000
FS: 00007ffb43869700(0000) GS:ffff88007d400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000007a3e9000 CR4: 00000000001406e0
Stack:
ffffc90000babe00 ffffffff81572d08 ffffffff81572bd5 0000000000000002
0000000000000000 ffff880079606600 00007ffb4386e000 ffffc90000babe20
ffffffff81573201 ffff880036a3fd00 fffffffffffffffb ffffc90000babe40
Call Trace:
__handle_sysrq+0x138/0x220
? __handle_sysrq+0x5/0x220
write_sysrq_trigger+0x51/0x60
proc_reg_write+0x42/0x70
__vfs_write+0x37/0x140
? preempt_count_sub+0xa1/0x100
? __sb_start_write+0xf5/0x210
? vfs_write+0x183/0x1a0
vfs_write+0xb8/0x1a0
SyS_write+0x58/0xc0
entry_SYSCALL_64_fastpath+0x1f/0xc2
RIP: 0033:0x7ffb42f55940
RSP: 002b:00007ffd33bb6b18 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000046 RCX: 00007ffb42f55940
RDX: 0000000000000002 RSI: 00007ffb4386e000 RDI: 0000000000000001
RBP: 0000000000000011 R08: 00007ffb4321ea40 R09: 00007ffb43869700
R10: 00007ffb43869700 R11: 0000000000000246 R12: 0000000000778a10
R13: 00007ffd33bb5c00 R14: 0000000000000007 R15: 0000000000000010
Code: 34 e8 d0 34 bc ff 48 c7 c2 3b 2b 57 81 be 01 00 00 00 48 c7 c7 e0 dd e5 81 e8 a8 55 ba ff c7 05 0e 3f de 00 01 00 00 00 0f ae f8 <c6> 04 25 00 00 00 00 01 5d c3 e8 4c 49 bc ff 84 c0 75 c3 48 c7
RIP: sysrq_handle_crash+0x45/0x80 RSP: ffffc90000babdc8
CR2: 0000000000000000
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andy Lutomirski <luto@kernel.org>
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: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/69329cb29b8f324bb5fcea14d61d224807fb6488.1477405374.git.jpoimboe@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull uaccess.h prepwork from Al Viro:
"Preparations to tree-wide switch to use of linux/uaccess.h (which,
obviously, will allow to start unifying stuff for real). The last step
there, ie
PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>'
sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \
`git grep -l "$PATT"|grep -v ^include/linux/uaccess.h`
is not taken here - I would prefer to do it once just before or just
after -rc1. However, everything should be ready for it"
* 'work.uaccess2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
remove a stray reference to asm/uaccess.h in docs
sparc64: separate extable_64.h, switch elf_64.h to it
score: separate extable.h, switch module.h to it
mips: separate extable.h, switch module.h to it
x86: separate extable.h, switch sections.h to it
remove stray include of asm/uaccess.h from cacheflush.h
mn10300: remove a bogus processor.h->uaccess.h include
xtensa: split uaccess.h into C and asm sides
bonding: quit messing with IOCTL
kill __kernel_ds_p off
mn10300: finish verify_area() off
frv: move HAVE_ARCH_UNMAPPED_AREA to pgtable.h
exceptions: detritus removal
Pull protection keys syscall interface from Thomas Gleixner:
"This is the final step of Protection Keys support which adds the
syscalls so user space can actually allocate keys and protect memory
areas with them. Details and usage examples can be found in the
documentation.
The mm side of this has been acked by Mel"
* 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/pkeys: Update documentation
x86/mm/pkeys: Do not skip PKRU register if debug registers are not used
x86/pkeys: Fix pkeys build breakage for some non-x86 arches
x86/pkeys: Add self-tests
x86/pkeys: Allow configuration of init_pkru
x86/pkeys: Default to a restrictive init PKRU
pkeys: Add details of system call use to Documentation/
generic syscalls: Wire up memory protection keys syscalls
x86: Wire up protection keys system calls
x86/pkeys: Allocation/free syscalls
x86/pkeys: Make mprotect_key() mask off additional vm_flags
mm: Implement new pkey_mprotect() system call
x86/pkeys: Add fault handling for PF_PK page fault bit
Pull x86 cleanups from Ingo Molnar:
"Header file and a wrapper functions cleanup"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: Migrate exception table users off module.h and onto extable.h
x86: Clean up various simple wrapper functions
These files were only including module.h for exception table related
functions. We've now separated that content out into its own file
"extable.h" so now move over to that and avoid all the extra header content
in module.h that we don't really need to compile these files.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/20160919210418.30243-1-paul.gortmaker@windriver.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If we get a page fault indicating kernel stack overflow, invoke
handle_stack_overflow(). To prevent us from overflowing the stack
again while handling the overflow (because we are likely to have
very little stack space left), call handle_stack_overflow() on the
double-fault stack.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
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: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/6d6cf96b3fb9b4c9aa303817e1dc4de0c7c36487.1472603235.git.luto@kernel.org
[ Minor edit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Rename it to match the thread_struct::uaccess_err pattern and also
because it was too long.
Cc: Andy Lutomirski <luto@kernel.org>
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: Josh Poimboeuf <jpoimboe@redhat.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
Signed-off-by: Ingo Molnar <mingo@kernel.org>
struct thread_info is a legacy mess. To prepare for its partial removal,
move the uaccess control fields out -- they're straightforward.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
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: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/d0ac4d01c8e4d4d756264604e47445d5acc7900e.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
If we get a vmalloc fault while current->active_mm->pgd doesn't
match CR3, we'll crash without this change. I've seen this failure
mode on heavily instrumented kernels with virtually mapped stacks.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
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: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/4650d7674185f165ed8fdf9ac4c5c35c5c179ba8.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
x86's page fault handlers had two TASK_SIZE uses that should have
been TASK_SIZE_MAX. I don't think that either one had a visible
effect, but this makes the code clearer and should save a few bytes
of text.
(And I eventually want to eradicate TASK_SIZE. This will help.)
Reported-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
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: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ruslan Kabatsayev <b7.10110111@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1242fb23b0d05c3069dbf5758ac55d26bc114bef.1462914565.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 protection key support from Ingo Molnar:
"This tree adds support for a new memory protection hardware feature
that is available in upcoming Intel CPUs: 'protection keys' (pkeys).
There's a background article at LWN.net:
https://lwn.net/Articles/643797/
The gist is that protection keys allow the encoding of
user-controllable permission masks in the pte. So instead of having a
fixed protection mask in the pte (which needs a system call to change
and works on a per page basis), the user can map a (handful of)
protection mask variants and can change the masks runtime relatively
cheaply, without having to change every single page in the affected
virtual memory range.
This allows the dynamic switching of the protection bits of large
amounts of virtual memory, via user-space instructions. It also
allows more precise control of MMU permission bits: for example the
executable bit is separate from the read bit (see more about that
below).
This tree adds the MM infrastructure and low level x86 glue needed for
that, plus it adds a high level API to make use of protection keys -
if a user-space application calls:
mmap(..., PROT_EXEC);
or
mprotect(ptr, sz, PROT_EXEC);
(note PROT_EXEC-only, without PROT_READ/WRITE), the kernel will notice
this special case, and will set a special protection key on this
memory range. It also sets the appropriate bits in the Protection
Keys User Rights (PKRU) register so that the memory becomes unreadable
and unwritable.
So using protection keys the kernel is able to implement 'true'
PROT_EXEC on x86 CPUs: without protection keys PROT_EXEC implies
PROT_READ as well. Unreadable executable mappings have security
advantages: they cannot be read via information leaks to figure out
ASLR details, nor can they be scanned for ROP gadgets - and they
cannot be used by exploits for data purposes either.
We know about no user-space code that relies on pure PROT_EXEC
mappings today, but binary loaders could start making use of this new
feature to map binaries and libraries in a more secure fashion.
There is other pending pkeys work that offers more high level system
call APIs to manage protection keys - but those are not part of this
pull request.
Right now there's a Kconfig that controls this feature
(CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS) that is default enabled
(like most x86 CPU feature enablement code that has no runtime
overhead), but it's not user-configurable at the moment. If there's
any serious problem with this then we can make it configurable and/or
flip the default"
* 'mm-pkeys-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (38 commits)
x86/mm/pkeys: Fix mismerge of protection keys CPUID bits
mm/pkeys: Fix siginfo ABI breakage caused by new u64 field
x86/mm/pkeys: Fix access_error() denial of writes to write-only VMA
mm/core, x86/mm/pkeys: Add execute-only protection keys support
x86/mm/pkeys: Create an x86 arch_calc_vm_prot_bits() for VMA flags
x86/mm/pkeys: Allow kernel to modify user pkey rights register
x86/fpu: Allow setting of XSAVE state
x86/mm: Factor out LDT init from context init
mm/core, x86/mm/pkeys: Add arch_validate_pkey()
mm/core, arch, powerpc: Pass a protection key in to calc_vm_flag_bits()
x86/mm/pkeys: Actually enable Memory Protection Keys in the CPU
x86/mm/pkeys: Add Kconfig prompt to existing config option
x86/mm/pkeys: Dump pkey from VMA in /proc/pid/smaps
x86/mm/pkeys: Dump PKRU with other kernel registers
mm/core, x86/mm/pkeys: Differentiate instruction fetches
x86/mm/pkeys: Optimize fault handling in access_error()
mm/core: Do not enforce PKEY permissions on remote mm access
um, pkeys: Add UML arch_*_access_permitted() methods
mm/gup, x86/mm/pkeys: Check VMAs and PTEs for protection keys
x86/mm/gup: Simplify get_user_pages() PTE bit handling
...
Andrey Wagin reported that a simple test case was broken by:
2b5f7d013fc ("mm/core, x86/mm/pkeys: Add execute-only protection keys support")
This test case creates an unreadable VMA and my patch assumed
that all writes must be to readable VMAs.
The simplest fix for this is to remove the pkey-related bits
in access_error(). For execute-only support, I believe the
existing version is sufficient because the permissions we
are trying to enforce are entirely expressed in vma->vm_flags.
We just depend on pkeys to get *an* exception, it does not
matter that PF_PK was set, or even what state PKRU is in.
I will re-add the necessary bits with the full pkeys
implementation that includes the new syscalls.
The three cases that matter are:
1. If a write to an execute-only VMA occurs, we will see PF_WRITE
set, but !VM_WRITE on the VMA, and return 1. All execute-only
VMAs have VM_WRITE clear by definition.
2. If a read occurs on a present PTE, we will fall in to the "read,
present" case and return 1.
3. If a read occurs to a non-present PTE, we will miss the "read,
not present" case, because the execute-only VMA will have
VM_EXEC set, and we will properly return 0 allowing the PTE to
be populated.
Test program:
int main()
{
int *p;
p = mmap(NULL, 4096, PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
p[0] = 1;
return 0;
}
Reported-by: Andrey Wagin <avagin@gmail.com>,
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-mm@kvack.org
Cc: linux-next@vger.kernel.org
Fixes: 62b5f7d013 ("mm/core, x86/mm/pkeys: Add execute-only protection keys support")
Link: http://lkml.kernel.org/r/20160301194133.65D0110C@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Protection keys provide new page-based protection in hardware.
But, they have an interesting attribute: they only affect data
accesses and never affect instruction fetches. That means that
if we set up some memory which is set as "access-disabled" via
protection keys, we can still execute from it.
This patch uses protection keys to set up mappings to do just that.
If a user calls:
mmap(..., PROT_EXEC);
or
mprotect(ptr, sz, PROT_EXEC);
(note PROT_EXEC-only without PROT_READ/WRITE), the kernel will
notice this, and set a special protection key on the memory. It
also sets the appropriate bits in the Protection Keys User Rights
(PKRU) register so that the memory becomes unreadable and
unwritable.
I haven't found any userspace that does this today. With this
facility in place, we expect userspace to move to use it
eventually. Userspace _could_ start doing this today. Any
PROT_EXEC calls get converted to PROT_READ inside the kernel, and
would transparently be upgraded to "true" PROT_EXEC with this
code. IOW, userspace never has to do any PROT_EXEC runtime
detection.
This feature provides enhanced protection against leaking
executable memory contents. This helps thwart attacks which are
attempting to find ROP gadgets on the fly.
But, the security provided by this approach is not comprehensive.
The PKRU register which controls access permissions is a normal
user register writable from unprivileged userspace. An attacker
who can execute the 'wrpkru' instruction can easily disable the
protection provided by this feature.
The protection key that is used for execute-only support is
permanently dedicated at compile time. This is fine for now
because there is currently no API to set a protection key other
than this one.
Despite there being a constant PKRU value across the entire
system, we do not set it unless this feature is in use in a
process. That is to preserve the PKRU XSAVE 'init state',
which can lead to faster context switches.
PKRU *is* a user register and the kernel is modifying it. That
means that code doing:
pkru = rdpkru()
pkru |= 0x100;
mmap(..., PROT_EXEC);
wrpkru(pkru);
could lose the bits in PKRU that enforce execute-only
permissions. To avoid this, we suggest avoiding ever calling
mmap() or mprotect() when the PKRU value is expected to be
unstable.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Chen Gang <gang.chen.5i5j@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Piotr Kwapulinski <kwapulinski.piotr@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Vladimir Murzin <vladimir.murzin@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: keescook@google.com
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210240.CB4BB5CA@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
As discussed earlier, we attempt to enforce protection keys in
software.
However, the code checks all faults to ensure that they are not
violating protection key permissions. It was assumed that all
faults are either write faults where we check PKRU[key].WD (write
disable) or read faults where we check the AD (access disable)
bit.
But, there is a third category of faults for protection keys:
instruction faults. Instruction faults never run afoul of
protection keys because they do not affect instruction fetches.
So, plumb the PF_INSTR bit down in to the
arch_vma_access_permitted() function where we do the protection
key checks.
We also add a new FAULT_FLAG_INSTRUCTION. This is because
handle_mm_fault() is not passed the architecture-specific
error_code where we keep PF_INSTR, so we need to encode the
instruction fetch information in to the arch-generic fault
flags.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
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: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210224.96928009@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
We might not strictly have to make modifictions to
access_error() to check the VMA here.
If we do not, we will do this:
1. app sets VMA pkey to K
2. app touches a !present page
3. do_page_fault(), allocates and maps page, sets pte.pkey=K
4. return to userspace
5. touch instruction reexecutes, but triggers PF_PK
6. do PKEY signal
What happens with this patch applied:
1. app sets VMA pkey to K
2. app touches a !present page
3. do_page_fault() notices that K is inaccessible
4. do PKEY signal
We basically skip the fault that does an allocation.
So what this lets us do is protect areas from even being
*populated* unless it is accessible according to protection
keys. That seems handy to me and makes protection keys work
more like an mprotect()'d mapping.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
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: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210222.EBB63D8C@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Today, for normal faults and page table walks, we check the VMA
and/or PTE to ensure that it is compatible with the action. For
instance, if we get a write fault on a non-writeable VMA, we
SIGSEGV.
We try to do the same thing for protection keys. Basically, we
try to make sure that if a user does this:
mprotect(ptr, size, PROT_NONE);
*ptr = foo;
they see the same effects with protection keys when they do this:
mprotect(ptr, size, PROT_READ|PROT_WRITE);
set_pkey(ptr, size, 4);
wrpkru(0xffffff3f); // access disable pkey 4
*ptr = foo;
The state to do that checking is in the VMA, but we also
sometimes have to do it on the page tables only, like when doing
a get_user_pages_fast() where we have no VMA.
We add two functions and expose them to generic code:
arch_pte_access_permitted(pte_flags, write)
arch_vma_access_permitted(vma, write)
These are, of course, backed up in x86 arch code with checks
against the PTE or VMA's protection key.
But, there are also cases where we do not want to respect
protection keys. When we ptrace(), for instance, we do not want
to apply the tracer's PKRU permissions to the PTEs from the
process being traced.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: David Hildenbrand <dahi@linux.vnet.ibm.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Dominik Dingel <dingel@linux.vnet.ibm.com>
Cc: Dominik Vogt <vogt@linux.vnet.ibm.com>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jason Low <jason.low2@hp.com>
Cc: Jerome Marchand <jmarchan@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Shachar Raindel <raindel@mellanox.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-mm@kvack.org
Cc: linux-s390@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20160212210219.14D5D715@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This fills in the new siginfo field: si_pkey to indicate to
userspace which protection key was set on the PTE that we faulted
on.
Note though that *ALL* protection key faults have to be generated
by a valid, present PTE at some point. But this code does no PTE
lookups which seeds odd. The reason is that we take advantage of
the way we generate PTEs from VMAs. All PTEs under a VMA share
some attributes. For instance, they are _all_ either PROT_READ
*OR* PROT_NONE. They also always share a protection key, so we
never have to walk the page tables; we just use the VMA.
Note that _pkey is a 64-bit value. The current hardware only
supports 4-bit protection keys. We do this because there is
_plenty_ of space in _sigfault and it is possible that future
processors would support more than 4 bits of protection keys.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
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: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210213.ABC488FA@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
During a page fault, we look up the VMA to ensure that the fault
is in a region with a valid mapping. But, in the top-level page
fault code we don't need the VMA for much else. Once we have
decided that an access is bad, we are going to send a signal no
matter what and do not need the VMA any more. So we do not pass
it down in to the signal generation code.
But, for protection keys, we need the VMA. It tells us *which*
protection key we violated if we get a PF_PK. So, we need to
pass the VMA down and fill in siginfo->si_pkey.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
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: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210211.AD3B36A3@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Note: "PK" is how the Intel SDM refers to this bit, so we also
use that nomenclature.
This only defines the bit, it does not plumb it anywhere to be
handled.
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
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: Rik van Riel <riel@redhat.com>
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20160212210207.DA7B43E6@viggo.jf.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Huge amounts of help from Andy Lutomirski and Borislav Petkov to
produce this. Andy provided the inspiration to add classes to the
exception table with a clever bit-squeezing trick, Boris pointed
out how much cleaner it would all be if we just had a new field.
Linus Torvalds blessed the expansion with:
' I'd rather not be clever in order to save just a tiny amount of space
in the exception table, which isn't really criticial for anybody. '
The third field is another relative function pointer, this one to a
handler that executes the actions.
We start out with three handlers:
1: Legacy - just jumps the to fixup IP
2: Fault - provide the trap number in %ax to the fixup code
3: Cleaned up legacy for the uaccess error hack
Signed-off-by: Tony Luck <tony.luck@intel.com>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/f6af78fcbd348cf4939875cfda9c19689b5e50b8.1455732970.git.tony.luck@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
A kernel page fault oops with the callstack below was observed
when a read syscall was made to a pmem device after a huge amount
(>512GB) of vmalloc ranges was allocated by ioremap() on a x86_64
system:
BUG: unable to handle kernel paging request at ffff880840000ff8
IP: vmalloc_fault+0x1be/0x300
PGD c7f03a067 PUD 0
Oops: 0000 [#1] SM
Call Trace:
__do_page_fault+0x285/0x3e0
do_page_fault+0x2f/0x80
? put_prev_entity+0x35/0x7a0
page_fault+0x28/0x30
? memcpy_erms+0x6/0x10
? schedule+0x35/0x80
? pmem_rw_bytes+0x6a/0x190 [nd_pmem]
? schedule_timeout+0x183/0x240
btt_log_read+0x63/0x140 [nd_btt]
:
? __symbol_put+0x60/0x60
? kernel_read+0x50/0x80
SyS_finit_module+0xb9/0xf0
entry_SYSCALL_64_fastpath+0x1a/0xa4
Since v4.1, ioremap() supports large page (pud/pmd) mappings in
x86_64 and PAE. vmalloc_fault() however assumes that the vmalloc
range is limited to pte mappings.
vmalloc faults do not normally happen in ioremap'd ranges since
ioremap() sets up the kernel page tables, which are shared by
user processes. pgd_ctor() sets the kernel's PGD entries to
user's during fork(). When allocation of the vmalloc ranges
crosses a 512GB boundary, ioremap() allocates a new pud table
and updates the kernel PGD entry to point it. If user process's
PGD entry does not have this update yet, a read/write syscall
to the range will cause a vmalloc fault, which hits the Oops
above as it does not handle a large page properly.
Following changes are made to vmalloc_fault().
64-bit:
- No change for the PGD sync operation as it handles large
pages already.
- Add pud_huge() and pmd_huge() to the validation code to
handle large pages.
- Change pud_page_vaddr() to pud_pfn() since an ioremap range
is not directly mapped (while the if-statement still works
with a bogus addr).
- Change pmd_page() to pmd_pfn() since an ioremap range is not
backed by struct page (while the if-statement still works
with a bogus addr).
32-bit:
- No change for the sync operation since the index3 PGD entry
covers the entire vmalloc range, which is always valid.
(A separate change to sync PGD entry is necessary if this
memory layout is changed regardless of the page size.)
- Add pmd_huge() to the validation code to handle large pages.
This is for completeness since vmalloc_fault() won't happen
in ioremap'd ranges as its PGD entry is always valid.
Reported-by: Henning Schild <henning.schild@siemens.com>
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Acked-by: Borislav Petkov <bp@alien8.de>
Cc: <stable@vger.kernel.org> # 4.1+
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Cc: linux-mm@kvack.org
Cc: linux-nvdimm@lists.01.org
Link: http://lkml.kernel.org/r/1455758214-24623-1-git-send-email-toshi.kani@hpe.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
vm86.h was being implicitly included in alot of places via
processor.h, which in turn got it from math_emu.h. Break that
chain and explicitly include vm86.h in all files that need it.
Also remove unused vm86 field from math_emu_info.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
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>
Link: http://lkml.kernel.org/r/1438148483-11932-7-git-send-email-brgerst@gmail.com
[ Fixed build failure. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Allocate a separate structure for the vm86 fields.
Signed-off-by: Brian Gerst <brgerst@gmail.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
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>
Link: http://lkml.kernel.org/r/1438148483-11932-2-git-send-email-brgerst@gmail.com
[ Build fixes. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Introduce faulthandler_disabled() and use it to check for irq context and
disabled pagefaults (via pagefault_disable()) in the pagefault handlers.
Please note that we keep the in_atomic() checks in place - to detect
whether in irq context (in which case preemption is always properly
disabled).
In contrast, preempt_disable() should never be used to disable pagefaults.
With !CONFIG_PREEMPT_COUNT, preempt_disable() doesn't modify the preempt
counter, and therefore the result of in_atomic() differs.
We validate that condition by using might_fault() checks when calling
might_sleep().
Therefore, add a comment to faulthandler_disabled(), describing why this
is needed.
faulthandler_disabled() and pagefault_disable() are defined in
linux/uaccess.h, so let's properly add that include to all relevant files.
This patch is based on a patch from Thomas Gleixner.
Reviewed-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: David.Laight@ACULAB.COM
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: airlied@linux.ie
Cc: akpm@linux-foundation.org
Cc: benh@kernel.crashing.org
Cc: bigeasy@linutronix.de
Cc: borntraeger@de.ibm.com
Cc: daniel.vetter@intel.com
Cc: heiko.carstens@de.ibm.com
Cc: herbert@gondor.apana.org.au
Cc: hocko@suse.cz
Cc: hughd@google.com
Cc: mst@redhat.com
Cc: paulus@samba.org
Cc: ralf@linux-mips.org
Cc: schwidefsky@de.ibm.com
Cc: yang.shi@windriver.com
Link: http://lkml.kernel.org/r/1431359540-32227-7-git-send-email-dahi@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
user_mode_vm() and user_mode() are now the same. Change all callers
of user_mode_vm() to user_mode().
The next patch will remove the definition of user_mode_vm.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/43b1f57f3df70df5a08b0925897c660725015554.1426728647.git.luto@kernel.org
[ Merged to a more recent kernel. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This is slightly shorter and slightly faster. It's also more
correct: the split between user and kernel addresses is
TASK_SIZE_MAX, regardless of ti->flags.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/09156b63bad90a327827003c9e53faa82ef4c56e.1426728647.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Context switches and TLB flushes can change individual bits of CR4.
CR4 reads take several cycles, so store a shadow copy of CR4 in a
per-cpu variable.
To avoid wasting a cache line, I added the CR4 shadow to
cpu_tlbstate, which is already touched in switch_mm. The heaviest
users of the cr4 shadow will be switch_mm and __switch_to_xtra, and
__switch_to_xtra is called shortly after switch_mm during context
switch, so the cacheline is likely to be hot.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Vince Weaver <vince@deater.net>
Cc: "hillf.zj" <hillf.zj@alibaba-inc.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/3a54dd3353fffbf84804398e00dfdc5b7c1afd7d.1414190806.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The core VM already knows about VM_FAULT_SIGBUS, but cannot return a
"you should SIGSEGV" error, because the SIGSEGV case was generally
handled by the caller - usually the architecture fault handler.
That results in lots of duplication - all the architecture fault
handlers end up doing very similar "look up vma, check permissions, do
retries etc" - but it generally works. However, there are cases where
the VM actually wants to SIGSEGV, and applications _expect_ SIGSEGV.
In particular, when accessing the stack guard page, libsigsegv expects a
SIGSEGV. And it usually got one, because the stack growth is handled by
that duplicated architecture fault handler.
However, when the generic VM layer started propagating the error return
from the stack expansion in commit fee7e49d45 ("mm: propagate error
from stack expansion even for guard page"), that now exposed the
existing VM_FAULT_SIGBUS result to user space. And user space really
expected SIGSEGV, not SIGBUS.
To fix that case, we need to add a VM_FAULT_SIGSEGV, and teach all those
duplicate architecture fault handlers about it. They all already have
the code to handle SIGSEGV, so it's about just tying that new return
value to the existing code, but it's all a bit annoying.
This is the mindless minimal patch to do this. A more extensive patch
would be to try to gather up the mostly shared fault handling logic into
one generic helper routine, and long-term we really should do that
cleanup.
Just from this patch, you can generally see that most architectures just
copied (directly or indirectly) the old x86 way of doing things, but in
the meantime that original x86 model has been improved to hold the VM
semaphore for shorter times etc and to handle VM_FAULT_RETRY and other
"newer" things, so it would be a good idea to bring all those
improvements to the generic case and teach other architectures about
them too.
Reported-and-tested-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Jan Engelhardt <jengelh@inai.de>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com> # "s390 still compiles and boots"
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
My commit 26178ec11e ("x86: mm: consolidate VM_FAULT_RETRY handling")
had a really stupid typo: the FAULT_FLAG_USER bit is in the 'flags'
variable, not the 'fault' variable. Duh,
The one silver lining in this is that Dave finding this at least
confirms that trinity actually triggers this special path easily, in a
way normal use does not.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The VM_FAULT_RETRY handling was confusing and incorrect for the case of
returning to kernel mode. We need to handle the exception table fixup
if we return to kernel mode due to a fatal signal - it will basically
look to the kernel user mode access like the access failed due to the VM
going away from udner it. Which is correct - the process is dying - and
avoids the whole "repeat endless kernel page faults" case.
Handling the VM_FAULT_RETRY early and in just one place also simplifies
the mmap_sem handling, since once we've taken care of VM_FAULT_RETRY we
know that we can just drop the lock. The remaining accounting and
possible error handling is thread-local and does not need the mmap_sem.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This replaces four copies in various stages of mm_fault_error() handling
with just a single one. It will also allow for more natural placement
of the unlocking after some further cleanup.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 mm updates from Ingo Molnar:
"This tree includes the following changes:
- fix memory hotplug
- fix hibernation bootup memory layout assumptions
- fix hyperv numa guest kernel messages
- remove dead code
- update documentation"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Update memory map description to list hypervisor-reserved area
x86/mm, hibernate: Do not assume the first e820 area to be RAM
x86/mm/numa: Drop dead code and rename setup_node_data() to setup_alloc_data()
x86/mm/hotplug: Modify PGD entry when removing memory
x86/mm/hotplug: Pass sync_global_pgds() a correct argument in remove_pagetable()
x86: Remove set_pmd_pfn
Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- Optimized support for Intel "Cluster-on-Die" (CoD) topologies (Dave
Hansen)
- Various sched/idle refinements for better idle handling (Nicolas
Pitre, Daniel Lezcano, Chuansheng Liu, Vincent Guittot)
- sched/numa updates and optimizations (Rik van Riel)
- sysbench speedup (Vincent Guittot)
- capacity calculation cleanups/refactoring (Vincent Guittot)
- Various cleanups to thread group iteration (Oleg Nesterov)
- Double-rq-lock removal optimization and various refactorings
(Kirill Tkhai)
- various sched/deadline fixes
... and lots of other changes"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (72 commits)
sched/dl: Use dl_bw_of() under rcu_read_lock_sched()
sched/fair: Delete resched_cpu() from idle_balance()
sched, time: Fix build error with 64 bit cputime_t on 32 bit systems
sched: Improve sysbench performance by fixing spurious active migration
sched/x86: Fix up typo in topology detection
x86, sched: Add new topology for multi-NUMA-node CPUs
sched/rt: Use resched_curr() in task_tick_rt()
sched: Use rq->rd in sched_setaffinity() under RCU read lock
sched: cleanup: Rename 'out_unlock' to 'out_free_new_mask'
sched: Use dl_bw_of() under RCU read lock
sched/fair: Remove duplicate code from can_migrate_task()
sched, mips, ia64: Remove __ARCH_WANT_UNLOCKED_CTXSW
sched: print_rq(): Don't use tasklist_lock
sched: normalize_rt_tasks(): Don't use _irqsave for tasklist_lock, use task_rq_lock()
sched: Fix the task-group check in tg_has_rt_tasks()
sched/fair: Leverage the idle state info when choosing the "idlest" cpu
sched: Let the scheduler see CPU idle states
sched/deadline: Fix inter- exclusive cpusets migrations
sched/deadline: Clear dl_entity params when setscheduling to different class
sched/numa: Kill the wrong/dead TASK_DEAD check in task_numa_fault()
...
If a fault on a kernel address is due to a non-present page, then it
cannot be the result of stale TLB entry from a protection change (RO
to RW or NX to X). Thus the pagetable walk in spurious_fault() can be
skipped.
See the initial if in spurious_fault() and the tests in
spurious_fault_check()) for the set of possible error codes checked
for spurious faults. These are:
IRUWP
Before x00xx && ( 1xxxx || xxx1x )
After ( 10001 || 00011 ) && ( 1xxxx || xxx1x )
Thus the new condition is a subset of the previous one, excluding only
non-present faults (I == 1 and W == 1 are mutually exclusive).
This avoids spurious_fault() oopsing in some cases if the pagetables
it attempts to walk are not accessible. This obscures the location of
the original fault.
This also fixes a crash with Xen PV guests when they access entries in
the M2P corresponding to device MMIO regions. The M2P is mapped
(read-only) by Xen into the kernel address space of the guest and this
mapping may contains holes for non-RAM regions. Read faults will
result in calls to spurious_fault(), but because the page tables for
the M2P mappings are not accessible by the guest the pagetable walk
would fault.
This was not normally a problem as MMIO mappings would not normally
result in a M2P lookup because of the use of the _PAGE_IOMAP bit the
PTE. However, removing the _PAGE_IOMAP bit requires M2P lookups for
MMIO mappings as well.
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Tasks get their end of stack set to STACK_END_MAGIC with the
aim to catch stack overruns. Currently this feature does not
apply to init_task. This patch removes this restriction.
Note that a similar patch was posted by Prarit Bhargava
some time ago but was never merged:
http://marc.info/?l=linux-kernel&m=127144305403241&w=2
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Cc: aneesh.kumar@linux.vnet.ibm.com
Cc: dzickus@redhat.com
Cc: bmr@redhat.com
Cc: jcastillo@redhat.com
Cc: jgh@redhat.com
Cc: minchan@kernel.org
Cc: tglx@linutronix.de
Cc: hannes@cmpxchg.org
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Daeseok Youn <daeseok.youn@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Fabian Frederick <fabf@skynet.be>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1410527779-8133-2-git-send-email-atomlin@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When hot-adding/removing memory, sync_global_pgds() is called
for synchronizing PGD to PGD entries of all processes MM. But
when hot-removing memory, sync_global_pgds() does not work
correctly.
At first, sync_global_pgds() checks whether target PGD is none
or not. And if PGD is none, the PGD is skipped. But when
hot-removing memory, PGD may be none since PGD may be cleared by
free_pud_table(). So when sync_global_pgds() is called after
hot-removing memory, sync_global_pgds() should not skip PGD even
if the PGD is none. And sync_global_pgds() must clear PGD
entries of all processes MM.
Currently sync_global_pgds() does not clear PGD entries of all
processes MM when hot-removing memory. So when hot adding
memory which is same memory range as removed memory after
hot-removing memory, following call traces are shown:
kernel BUG at arch/x86/mm/init_64.c:206!
...
[<ffffffff815e0c80>] kernel_physical_mapping_init+0x1b2/0x1d2
[<ffffffff815ced94>] init_memory_mapping+0x1d4/0x380
[<ffffffff8104aebd>] arch_add_memory+0x3d/0xd0
[<ffffffff815d03d9>] add_memory+0xb9/0x1b0
[<ffffffff81352415>] acpi_memory_device_add+0x1af/0x28e
[<ffffffff81325dc4>] acpi_bus_device_attach+0x8c/0xf0
[<ffffffff813413b9>] acpi_ns_walk_namespace+0xc8/0x17f
[<ffffffff81325d38>] ? acpi_bus_type_and_status+0xb7/0xb7
[<ffffffff81325d38>] ? acpi_bus_type_and_status+0xb7/0xb7
[<ffffffff813418ed>] acpi_walk_namespace+0x95/0xc5
[<ffffffff81326b4c>] acpi_bus_scan+0x9a/0xc2
[<ffffffff81326bff>] acpi_scan_bus_device_check+0x8b/0x12e
[<ffffffff81326cb5>] acpi_scan_device_check+0x13/0x15
[<ffffffff81320122>] acpi_os_execute_deferred+0x25/0x32
[<ffffffff8107e02b>] process_one_work+0x17b/0x460
[<ffffffff8107edfb>] worker_thread+0x11b/0x400
[<ffffffff8107ece0>] ? rescuer_thread+0x400/0x400
[<ffffffff81085aef>] kthread+0xcf/0xe0
[<ffffffff81085a20>] ? kthread_create_on_node+0x140/0x140
[<ffffffff815fc76c>] ret_from_fork+0x7c/0xb0
[<ffffffff81085a20>] ? kthread_create_on_node+0x140/0x140
This patch clears PGD entries of all processes MM when
sync_global_pgds() is called after hot-removing memory
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Acked-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
Cc: Gu Zheng <guz.fnst@cn.fujitsu.com>
Cc: Zhang Yanfei <zhangyanfei@cn.fujitsu.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add a comment describing the circumstances in which
__lock_page_or_retry() will or will not release the mmap_sem when
returning 0.
Add comments to lock_page_or_retry()'s callers (filemap_fault(),
do_swap_page()) noting the impact on VM_FAULT_RETRY returns.
Add comments on up the call tree, particularly replacing the false "We
return with mmap_sem still held" comments.
Signed-off-by: Paul Cassella <cassella@cray.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86 mm changes from Ingo Molnar:
"The main change in this cycle is the rework of the TLB range flushing
code, to simplify, fix and consolidate the code. By Dave Hansen"
* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mm: Set TLB flush tunable to sane value (33)
x86/mm: New tunable for single vs full TLB flush
x86/mm: Add tracepoints for TLB flushes
x86/mm: Unify remote INVLPG code
x86/mm: Fix missed global TLB flush stat
x86/mm: Rip out complicated, out-of-date, buggy TLB flushing
x86/mm: Clean up the TLB flushing code
x86/smep: Be more informative when signalling an SMEP fault
Pull more perf updates from Ingo Molnar:
"A second round of perf updates:
- wide reaching kprobes sanitization and robustization, with the hope
of fixing all 'probe this function crashes the kernel' bugs, by
Masami Hiramatsu.
- uprobes updates from Oleg Nesterov: tmpfs support, corner case
fixes and robustization work.
- perf tooling updates and fixes from Jiri Olsa, Namhyung Ki, Arnaldo
et al:
* Add support to accumulate hist periods (Namhyung Kim)
* various fixes, refactorings and enhancements"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (101 commits)
perf: Differentiate exec() and non-exec() comm events
perf: Fix perf_event_comm() vs. exec() assumption
uprobes/x86: Rename arch_uprobe->def to ->defparam, minor comment updates
perf/documentation: Add description for conditional branch filter
perf/x86: Add conditional branch filtering support
perf/tool: Add conditional branch filter 'cond' to perf record
perf: Add new conditional branch filter 'PERF_SAMPLE_BRANCH_COND'
uprobes: Teach copy_insn() to support tmpfs
uprobes: Shift ->readpage check from __copy_insn() to uprobe_register()
perf/x86: Use common PMU interrupt disabled code
perf/ARM: Use common PMU interrupt disabled code
perf: Disable sampled events if no PMU interrupt
perf: Fix use after free in perf_remove_from_context()
perf tools: Fix 'make help' message error
perf record: Fix poll return value propagation
perf tools: Move elide bool into perf_hpp_fmt struct
perf tools: Remove elide setup for SORT_MODE__MEMORY mode
perf tools: Fix "==" into "=" in ui_browser__warning assignment
perf tools: Allow overriding sysfs and proc finding with env var
perf tools: Consider header files outside perf directory in tags target
...
If pagefault triggers due to SMEP triggering, it can't be really easily
distinguished from any other oops-causing pagefault, which might lead to quite
some confusion when trying to understand the reason for the oops.
Print an explanatory message in case the fault happened during instruction
fetch for _PAGE_USER page which is present and executable on SMEP-enabled CPUs.
This is consistent with what we are doing for NX already; in addition to
immediately seeing from the oops what might be happening, it can even easily
give a good indication to sysadmins who are carefully monitoring their kernel
logs that someone might be trying to pwn them.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1406102248490.1321@pobox.suse.cz
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Use NOKPROBE_SYMBOL macro for protecting functions
from kprobes instead of __kprobes annotation under
arch/x86.
This applies nokprobe_inline annotation for some cases,
because NOKPROBE_SYMBOL() will inhibit inlining by
referring the symbol address.
This just folds a bunch of previous NOKPROBE_SYMBOL()
cleanup patches for x86 to one patch.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Link: http://lkml.kernel.org/r/20140417081814.26341.51656.stgit@ltc230.yrl.intra.hitachi.co.jp
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fernando Luis Vázquez Cao <fernando_b1@lab.ntt.co.jp>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Jesper Nilsson <jesper.nilsson@axis.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Slaby <jslaby@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Lebon <jlebon@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matt Fleming <matt.fleming@intel.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vineet Gupta <vgupta@synopsys.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull x86 EFI changes from Ingo Molnar:
"The main changes:
- Add debug code to the dump EFI pagetable - Borislav Petkov
- Make 1:1 runtime mapping robust when booting on machines with lots
of memory - Borislav Petkov
- Move the EFI facilities bits out of 'x86_efi_facility' and into
efi.flags which is the standard architecture independent place to
keep EFI state, by Matt Fleming.
- Add 'EFI mixed mode' support: this allows 64-bit kernels to be
booted from 32-bit firmware. This needs a bootloader that supports
the 'EFI handover protocol'. By Matt Fleming"
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits)
x86, efi: Abstract x86 efi_early calls
x86/efi: Restore 'attr' argument to query_variable_info()
x86/efi: Rip out phys_efi_get_time()
x86/efi: Preserve segment registers in mixed mode
x86/boot: Fix non-EFI build
x86, tools: Fix up compiler warnings
x86/efi: Re-disable interrupts after calling firmware services
x86/boot: Don't overwrite cr4 when enabling PAE
x86/efi: Wire up CONFIG_EFI_MIXED
x86/efi: Add mixed runtime services support
x86/efi: Firmware agnostic handover entry points
x86/efi: Split the boot stub into 32/64 code paths
x86/efi: Add early thunk code to go from 64-bit to 32-bit
x86/efi: Build our own EFI services pointer table
efi: Add separate 32-bit/64-bit definitions
x86/efi: Delete dead code when checking for non-native
x86/mm/pageattr: Always dump the right page table in an oops
x86, tools: Consolidate #ifdef code
x86/boot: Cleanup header.S by removing some #ifdefs
efi: Use NULL instead of 0 for pointer
...
Building on commit 0ac09f9f8c ("x86, trace: Fix CR2 corruption when
tracing page faults") this patch addresses another few issues:
- Now that read_cr2() is lifted into trace_do_page_fault(), we should
pass the address to trace_page_fault_entries() to avoid it
re-reading a potentially changed cr2.
- Put both trace_do_page_fault() and trace_page_fault_entries() under
CONFIG_TRACING.
- Mark both fault entry functions {,trace_}do_page_fault() as notrace
to avoid getting __mcount or other function entry trace callbacks
before we've observed CR2.
- Mark __do_page_fault() as noinline to guarantee the function tracer
does get to see the fault.
Cc: <jolsa@redhat.com>
Cc: <vincent.weaver@maine.edu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140306145300.GO9987@twins.programming.kicks-ass.net
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
The trace_do_page_fault function trigger tracepoint
and then handles the actual page fault.
This could lead to error if the tracepoint caused page
fault. The original cr2 value gets lost and the original
page fault handler kills current process with SIGSEGV.
This happens if you record page faults with callchain
data, the user part of it will cause tracepoint handler
to page fault:
# perf record -g -e exceptions:page_fault_user ls
Fixing this by saving the original cr2 value
and using it after tracepoint handler is done.
v2: Moving the cr2 read before exception_enter, because
it could trigger tracepoint as well.
Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1402211701380.6395@vincent-weaver-1.um.maine.edu
Link: http://lkml.kernel.org/r/20140228160526.GD1133@krava.brq.redhat.com
Now that we have EFI-specific page tables we need to lookup the pgd when
dumping those page tables, rather than assuming that swapper_pgdir is
the current pgdir.
Remove the double underscore prefix, which is usually reserved for
static functions.
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
If CONFIG_X86_SMAP is disabled, smap_violation() tests for conditions
which are incorrect (as the AC flag doesn't matter), causing spurious
faults.
The dynamic disabling of SMAP (nosmap on the command line) is fine
because it disables X86_FEATURE_SMAP, therefore causing the
static_cpu_has() to return false.
Found by Fengguang Wu's test system.
[ v3: move all predicates into smap_violation() ]
[ v2: use IS_ENABLED() instead of #ifdef ]
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Link: http://lkml.kernel.org/r/20140213124550.GA30497@localhost
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: <stable@vger.kernel.org> # v3.7+
Waiman managed to trigger a PMI while in a emulate_vsyscall() fault,
the PMI in turn managed to trigger a fault while obtaining a stack
trace. This triggered the sig_on_uaccess_error recursive fault logic
and killed the process dead.
Fix this by explicitly excluding interrupts from the recursive fault
logic.
Reported-and-Tested-by: Waiman Long <waiman.long@hp.com>
Fixes: e00b12e64b ("perf/x86: Further optimize copy_from_user_nmi()")
Cc: Aswin Chandramouleeswaran <aswin@hp.com>
Cc: Scott J Norton <scott.norton@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140110200603.GJ7572@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull two x86 fixes from Ingo Molnar.
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/microcode/amd: Tone down printk(), don't treat a missing firmware file as an error
x86/dumpstack: Fix printk_address for direct addresses
Pull x86/trace changes from Ingo Molnar:
"This adds page fault tracepoints which have zero runtime cost in the
disabled case via IDT trickery (no NOPs in the page fault hotpath)"
* 'x86-trace-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, trace: Change user|kernel_page_fault to page_fault_user|kernel
x86, trace: Add page fault tracepoints
x86, trace: Delete __trace_alloc_intr_gate()
x86, trace: Register exception handler to trace IDT
x86, trace: Remove __alloc_intr_gate()
Consider a kernel crash in a module, simulated the following way:
static int my_init(void)
{
char *map = (void *)0x5;
*map = 3;
return 0;
}
module_init(my_init);
When we turn off FRAME_POINTERs, the very first instruction in
that function causes a BUG. The problem is that we print IP in
the BUG report using %pB (from printk_address). And %pB
decrements the pointer by one to fix printing addresses of
functions with tail calls.
This was added in commit 71f9e59800 ("x86, dumpstack: Use
%pB format specifier for stack trace") to fix the call stack
printouts.
So instead of correct output:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000005
IP: [<ffffffffa01ac000>] my_init+0x0/0x10 [pb173]
We get:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000005
IP: [<ffffffffa0152000>] 0xffffffffa0151fff
To fix that, we use %pS only for stack addresses printouts (via
newly added printk_stack_address) and %pB for regs->ip (via
printk_address). I.e. we revert to the old behaviour for all
except call stacks. And since from all those reliable is 1, we
remove that parameter from printk_address.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: joe@perches.com
Cc: jirislaby@gmail.com
Link: http://lkml.kernel.org/r/1382706418-8435-1-git-send-email-jslaby@suse.cz
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tracepoints are named hierachially, and it makes more sense to keep a
general flow of information level from general to specific from left
to right, i.e.
x86_exceptions.page_fault_user|kernel
rather than
x86_exceptions.user|kernel_page_fault
Suggested-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Seiji Aguchi <seiji.aguchi@hds.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/r/20131111082955.GB12405@gmail.com
This patch registers exception handlers for tracing to a trace IDT.
To implemented it in set_intr_gate(), this patch does followings.
- Register the exception handlers to
the trace IDT by prepending "trace_" to the handler's names.
- Also, newly introduce trace_page_fault() to add tracepoints
in a subsequent patch.
Signed-off-by: Seiji Aguchi <seiji.aguchi@hds.com>
Link: http://lkml.kernel.org/r/52716DEC.5050204@hds.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Now that we can deal with nested NMI due to IRET re-enabling NMIs and
can deal with faults from NMI by making sure we preserve CR2 over NMIs
we can in fact simply access user-space memory from NMI context.
So rewrite copy_from_user_nmi() to use __copy_from_user_inatomic() and
rework the fault path to do the minimal required work before taking
the in_atomic() fault handler.
In particular avoid perf_sw_event() which would make perf recurse on
itself (it should be harmless as our recursion protections should be
able to deal with this -- but why tempt fate).
Also rename notify_page_fault() to kprobes_fault() as that is a much
better name; there is no notifier in it and its specific to kprobes.
Don measured that his worst case NMI path shrunk from ~300K cycles to
~150K cycles.
Cc: Stephane Eranian <eranian@google.com>
Cc: jmario@redhat.com
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: dave.hansen@linux.intel.com
Tested-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131024105206.GM2490@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The x86 fault handler bails in the middle of error handling when the
task has a fatal signal pending. For a subsequent patch this is a
problem in OOM situations because it relies on pagefault_out_of_memory()
being called even when the task has been killed, to perform proper
per-task OOM state unwinding.
Shortcutting the fault like this is a rather minor optimization that
saves a few instructions in rare cases. Just remove it for
user-triggered faults.
Use the opportunity to split the fault retry handling from actual fault
errors and add locking documentation that reads suprisingly similar to
ARM's.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Unlike global OOM handling, memory cgroup code will invoke the OOM killer
in any OOM situation because it has no way of telling faults occuring in
kernel context - which could be handled more gracefully - from
user-triggered faults.
Pass a flag that identifies faults originating in user space from the
architecture-specific fault handlers to generic code so that memcg OOM
handling can be improved.
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: azurIt <azurit@pobox.sk>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull scheduler changes from Ingo Molnar:
"The main changes in this development cycle were:
- full dynticks preparatory work by Frederic Weisbecker
- factor out the cpu time accounting code better, by Li Zefan
- multi-CPU load balancer cleanups and improvements by Joonsoo Kim
- various smaller fixes and cleanups"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (45 commits)
sched: Fix init NOHZ_IDLE flag
sched: Prevent to re-select dst-cpu in load_balance()
sched: Rename load_balance_tmpmask to load_balance_mask
sched: Move up affinity check to mitigate useless redoing overhead
sched: Don't consider other cpus in our group in case of NEWLY_IDLE
sched: Explicitly cpu_idle_type checking in rebalance_domains()
sched: Change position of resched_cpu() in load_balance()
sched: Fix wrong rq's runnable_avg update with rt tasks
sched: Document task_struct::personality field
sched/cpuacct/UML: Fix header file dependency bug on the UML build
cgroup: Kill subsys.active flag
sched/cpuacct: No need to check subsys active state
sched/cpuacct: Initialize cpuacct subsystem earlier
sched/cpuacct: Initialize root cpuacct earlier
sched/cpuacct: Allocate per_cpu cpuusage for root cpuacct statically
sched/cpuacct: Clean up cpuacct.h
sched/cpuacct: Remove redundant NULL checks in cpuacct_acount_field()
sched/cpuacct: Remove redundant NULL checks in cpuacct_charge()
sched/cpuacct: Add cpuacct_acount_field()
sched/cpuacct: Add cpuacct_init()
...
In paravirtualized x86_64 kernels, vmalloc_fault may cause an oops
when lazy MMU updates are enabled, because set_pgd effects are being
deferred.
One instance of this problem is during process mm cleanup with memory
cgroups enabled. The chain of events is as follows:
- zap_pte_range enables lazy MMU updates
- zap_pte_range eventually calls mem_cgroup_charge_statistics,
which accesses the vmalloc'd mem_cgroup per-cpu stat area
- vmalloc_fault is triggered which tries to sync the corresponding
PGD entry with set_pgd, but the update is deferred
- vmalloc_fault oopses due to a mismatch in the PUD entries
The OOPs usually looks as so:
------------[ cut here ]------------
kernel BUG at arch/x86/mm/fault.c:396!
invalid opcode: 0000 [#1] SMP
.. snip ..
CPU 1
Pid: 10866, comm: httpd Not tainted 3.6.10-4.fc18.x86_64 #1
RIP: e030:[<ffffffff816271bf>] [<ffffffff816271bf>] vmalloc_fault+0x11f/0x208
.. snip ..
Call Trace:
[<ffffffff81627759>] do_page_fault+0x399/0x4b0
[<ffffffff81004f4c>] ? xen_mc_extend_args+0xec/0x110
[<ffffffff81624065>] page_fault+0x25/0x30
[<ffffffff81184d03>] ? mem_cgroup_charge_statistics.isra.13+0x13/0x50
[<ffffffff81186f78>] __mem_cgroup_uncharge_common+0xd8/0x350
[<ffffffff8118aac7>] mem_cgroup_uncharge_page+0x57/0x60
[<ffffffff8115fbc0>] page_remove_rmap+0xe0/0x150
[<ffffffff8115311a>] ? vm_normal_page+0x1a/0x80
[<ffffffff81153e61>] unmap_single_vma+0x531/0x870
[<ffffffff81154962>] unmap_vmas+0x52/0xa0
[<ffffffff81007442>] ? pte_mfn_to_pfn+0x72/0x100
[<ffffffff8115c8f8>] exit_mmap+0x98/0x170
[<ffffffff810050d9>] ? __raw_callee_save_xen_pmd_val+0x11/0x1e
[<ffffffff81059ce3>] mmput+0x83/0xf0
[<ffffffff810624c4>] exit_mm+0x104/0x130
[<ffffffff8106264a>] do_exit+0x15a/0x8c0
[<ffffffff810630ff>] do_group_exit+0x3f/0xa0
[<ffffffff81063177>] sys_exit_group+0x17/0x20
[<ffffffff8162bae9>] system_call_fastpath+0x16/0x1b
Calling arch_flush_lazy_mmu_mode immediately after set_pgd makes the
changes visible to the consistency checks.
Cc: <stable@vger.kernel.org>
RedHat-Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=914737
Tested-by: Josh Boyer <jwboyer@redhat.com>
Reported-and-Tested-by: Krishna Raman <kraman@redhat.com>
Signed-off-by: Samu Kallio <samu.kallio@aberdeencloud.com>
Link: http://lkml.kernel.org/r/1364045796-10720-1-git-send-email-konrad.wilk@oracle.com
Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
On exception exit, we restore the previous context tracking state based on
the regs of the interrupted frame. Iff that frame is in user mode as
stated by user_mode() helper, we restore the context tracking user mode.
However there is a tiny chunck of low level arch code after we pass through
user_enter() and until the CPU eventually resumes userspace.
If an exception happens in this tiny area, exception_enter() correctly
exits the context tracking user mode but exception_exit() won't restore
it because of the value returned by user_mode(regs).
As a result we may return to userspace with the wrong context tracking
state.
To fix this, change exception_enter() to return the context tracking state
prior to its call and pass this saved state to exception_exit(). This restores
the real context tracking state of the interrupted frame.
(May be this patch was suggested to me, I don't recall exactly. If so,
sorry for the missing credit).
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Mats Liljegren <mats.liljegren@enea.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Exceptions handling on context tracking should share common
treatment: on entry we exit user mode if the exception triggered
in that context. Then on exception exit we return to that previous
context.
Generalize this to avoid duplication across archs.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Kevin Hilman <khilman@linaro.org>
Cc: Mats Liljegren <mats.liljegren@enea.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
I got a report for a minor regression introduced by commit
027ef6c878 ("mm: thp: fix pmd_present for split_huge_page and
PROT_NONE with THP").
So the problem is, pageattr creates kernel pagetables (pte and
pmds) that breaks pte_present/pmd_present and the patch above
exposed this invariant breakage for pmd_present.
The same problem already existed for the pte and pte_present and
it was fixed by commit 660a293ea9 ("x86, mm: Make
spurious_fault check explicitly check the PRESENT bit") (if it
wasn't for that commit, it wouldn't even be a regression). That
fix avoids the pagefault to use pte_present. I could follow
through by stopping using pmd_present/pmd_huge too.
However I think it's more robust to fix pageattr and to clear
the PSE/GLOBAL bitflags too in addition to the present bitflag.
So the kernel page fault can keep using the regular
pte_present/pmd_present/pmd_huge.
The confusion arises because _PAGE_GLOBAL and _PAGE_PROTNONE are
sharing the same bit, and in the pmd case we pretend _PAGE_PSE
to be set only in present pmds (to facilitate split_huge_page
final tlb flush).
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Shaohua Li <shaohua.li@intel.com>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Without this patch, it is trivial to determine kernel page
mappings by examining the error code reported to dmesg[1].
Instead, declare the entire kernel memory space as a violation
of a present page.
Additionally, since show_unhandled_signals is enabled by
default, switch branch hinting to the more realistic
expectation, and unobfuscate the setting of the PF_PROT bit to
improve readability.
[1] http://vulnfactory.org/blog/2013/02/06/a-linux-memory-trick/
Reported-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Suggested-by: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: stable@vger.kernel.org
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130207174413.GA12485@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
out_of_memory() is a globally defined function to call the oom killer.
x86, sh, and powerpc all use a function of the same name within file scope
in their respective fault.c unnecessarily. Inline the functions into the
pagefault handlers to clean the code up.
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Paul Mundt <lethal@linux-sh.org>
Reviewed-by: Michal Hocko <mhocko@suse.cz>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Create a new subsystem that probes on kernel boundaries
to keep track of the transitions between level contexts
with two basic initial contexts: user or kernel.
This is an abstraction of some RCU code that use such tracking
to implement its userspace extended quiescent state.
We need to pull this up from RCU into this new level of indirection
because this tracking is also going to be used to implement an "on
demand" generic virtual cputime accounting. A necessary step to
shutdown the tick while still accounting the cputime.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Li Zhong <zhong@linux.vnet.ibm.com>
Cc: Gilad Ben-Yossef <gilad@benyossef.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
[ paulmck: fix whitespace error and email address. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
.fault now can retry. The retry can break state machine of .fault. In
filemap_fault, if page is miss, ra->mmap_miss is increased. In the second
try, since the page is in page cache now, ra->mmap_miss is decreased. And
these are done in one fault, so we can't detect random mmap file access.
Add a new flag to indicate .fault is tried once. In the second try, skip
ra->mmap_miss decreasing. The filemap_fault state machine is ok with it.
I only tested x86, didn't test other archs, but looks the change for other
archs is obvious, but who knows :)
Signed-off-by: Shaohua Li <shaohua.li@fusionio.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull x86/smap support from Ingo Molnar:
"This adds support for the SMAP (Supervisor Mode Access Prevention) CPU
feature on Intel CPUs: a hardware feature that prevents unintended
user-space data access from kernel privileged code.
It's turned on automatically when possible.
This, in combination with SMEP, makes it even harder to exploit kernel
bugs such as NULL pointer dereferences."
Fix up trivial conflict in arch/x86/kernel/entry_64.S due to newly added
includes right next to each other.
* 'x86-smap-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, smep, smap: Make the switching functions one-way
x86, suspend: On wakeup always initialize cr4 and EFER
x86-32: Start out eflags and cr4 clean
x86, smap: Do not abuse the [f][x]rstor_checking() functions for user space
x86-32, smap: Add STAC/CLAC instructions to 32-bit kernel entry
x86, smap: Reduce the SMAP overhead for signal handling
x86, smap: A page fault due to SMAP is an oops
x86, smap: Turn on Supervisor Mode Access Prevention
x86, smap: Add STAC and CLAC instructions to control user space access
x86, uaccess: Merge prototypes for clear_user/__clear_user
x86, smap: Add a header file with macros for STAC/CLAC
x86, alternative: Add header guards to <asm/alternative-asm.h>
x86, alternative: Use .pushsection/.popsection
x86, smap: Add CR4 bit for SMAP
x86-32, mm: The WP test should be done on a kernel page
Add necessary hooks to x86 exception for userspace
RCU extended quiescent state support.
This includes traps, page fault, debug exceptions, etc...
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Alessio Igor Bogani <abogani@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Avi Kivity <avi@redhat.com>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Geoff Levand <geoff@infradead.org>
Cc: Gilad Ben Yossef <gilad@benyossef.com>
Cc: Hakan Akkan <hakanakkan@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kevin Hilman <khilman@ti.com>
Cc: Max Krasnyansky <maxk@qualcomm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
cred.h and a few trivial users of struct cred are changed. The rest of the users
of struct cred are left for other patches as there are too many changes to make
in one go and leave the change reviewable. If the user namespace is disabled and
CONFIG_UIDGID_STRICT_TYPE_CHECKS are disabled the code will contiue to compile
and behave correctly.
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
There are precedences of trap number being referred to as
trap_nr. However thread struct refers trap number as trap_no.
Change it to trap_nr.
Also use enum instead of left-over literals for trap values.
This is pure cleanup, no functional change intended.
Suggested-by: Ingo Molnar <mingo@eltu.hu>
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Linux-mm <linux-mm@kvack.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120312092555.5379.942.sendpatchset@srdronam.in.ibm.com
[ Fixed the math-emu build ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
rsyslog will display KERN_EMERG messages on a connected
terminal. However, these messages are useless/undecipherable
for a general user.
For example, after a softlockup we get:
Message from syslogd@intel-s3e37-04 at Jan 25 14:18:06 ...
kernel:Stack:
Message from syslogd@intel-s3e37-04 at Jan 25 14:18:06 ...
kernel:Call Trace:
Message from syslogd@intel-s3e37-04 at Jan 25 14:18:06 ...
kernel:Code: ff ff a8 08 75 25 31 d2 48 8d 86 38 e0 ff ff 48 89
d1 0f 01 c8 0f ae f0 48 8b 86 38 e0 ff ff a8 08 75 08 b1 01 4c 89 e0 0f 01 c9 <e8> ea 69 dd ff 4c 29 e8 48 89 c7 e8 0f bc da ff 49 89 c4 49 89
This happens because the printk levels for these messages are
incorrect. Only an informational message should be displayed on
a terminal.
I modified the printk levels for various messages in the kernel
and tested the output by using the drivers/misc/lkdtm.c kernel
modules (ie, softlockups, panics, hard lockups, etc.) and
confirmed that the console output was still the same and that
the output to the terminals was correct.
For example, in the case of a softlockup we now see the much
more informative:
Message from syslogd@intel-s3e37-04 at Jan 25 10:18:06 ...
BUG: soft lockup - CPU4 stuck for 60s!
instead of the above confusing messages.
AFAICT, the messages no longer have to be KERN_EMERG. In the
most important case of a panic we set console_verbose(). As for
the other less severe cases the correct data is output to the
console and /var/log/messages.
Successfully tested by me using the drivers/misc/lkdtm.c module.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Cc: dzickus@redhat.com
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/1327586134-11926-1-git-send-email-prarit@redhat.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
To make this work, we teach the page fault handler how to send
signals on failed uaccess. This only works for user addresses
(kernel addresses will never hit the page fault handler in the
first place), so we need to generate signals for those
separately.
This gets the tricky case right: if the user buffer spans
multiple pages and only the second page is invalid, we set
cr2 and si_addr correctly. UML relies on this behavior to
"fault in" pages as needed.
We steal a bit from thread_info.uaccess_err to enable this.
Before this change, uaccess_err was a 32-bit boolean value.
This fixes issues with UML when vsyscall=emulate.
Reported-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: richard -rw- weinberger <richard.weinberger@gmail.com>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/4c8f91de7ec5cd2ef0f59521a04e1015f11e42b4.1320712291.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86-64, doc: Remove int 0xcc from entry_64.S documentation
x86, vsyscall: Add missing <asm/fixmap.h> to arch/x86/mm/fault.c
Fix up trivial conflicts in arch/x86/mm/fault.c (asm/fixmap.h vs
asm/vsyscall.h: both work, which to use? Whatever..)
Erratum 93 applies to AMD K8 CPUs only, and its workaround
(forcing the upper 32 bits of %rip to all get set under certain
conditions) is actually getting in the way of analyzing page
faults occurring during EFI physical mode runtime calls (in
particular the page table walk shown is completely unrelated to
the actual fault). This is because typically EFI runtime code
lives in the space between 2G and 4G, which - modulo the above
manipulation - is likely to overlap with the kernel or modules
area.
While even for the other errata workarounds their taking effect
could be limited to just the affected CPUs, none of them appears
to be destructive, and they're generally getting called only
outside of performance critical paths, so they're being left
untouched.
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Link: http://lkml.kernel.org/r/4E835FE30200007800058464@nat28.tlf.novell.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/mm/fault.c now depend on having the symbol VSYSCALL_START
defined, which is best handled by including <asm/fixmap.h> (it isn't
unreasonable we may want other fixed addresses in this file in the
future, and so it is cleaner than including <asm/vsyscall.h>
directly.)
This addresses an x86-64 allnoconfig build failure. On other
configurations it was masked by an indirect path:
<asm/smp.h> -> <asm/apic.h> -> <asm/fixmap.h> -> <asm/vsyscall.h>
... however, the first such include is conditional on CONFIG_X86_LOCAL_APIC.
Originally-by: Randy Dunlap <rdunlap@xenotime.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/CA%2B55aFxsOMc9=p02r8-QhJ=h=Mqwckk4_Pnx9LQt5%2BfqMp_exQ@mail.gmail.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Ingo Molnar