Pull locking and misc x86 updates from Ingo Molnar:
"Lots of changes in this cycle - in part because locking/core attracted
a number of related x86 low level work which was easier to handle in a
single tree:
- Linux Kernel Memory Consistency Model updates (Alan Stern, Paul E.
McKenney, Andrea Parri)
- lockdep scalability improvements and micro-optimizations (Waiman
Long)
- rwsem improvements (Waiman Long)
- spinlock micro-optimization (Matthew Wilcox)
- qspinlocks: Provide a liveness guarantee (more fairness) on x86.
(Peter Zijlstra)
- Add support for relative references in jump tables on arm64, x86
and s390 to optimize jump labels (Ard Biesheuvel, Heiko Carstens)
- Be a lot less permissive on weird (kernel address) uaccess faults
on x86: BUG() when uaccess helpers fault on kernel addresses (Jann
Horn)
- macrofy x86 asm statements to un-confuse the GCC inliner. (Nadav
Amit)
- ... and a handful of other smaller changes as well"
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (57 commits)
locking/lockdep: Make global debug_locks* variables read-mostly
locking/lockdep: Fix debug_locks off performance problem
locking/pvqspinlock: Extend node size when pvqspinlock is configured
locking/qspinlock_stat: Count instances of nested lock slowpaths
locking/qspinlock, x86: Provide liveness guarantee
x86/asm: 'Simplify' GEN_*_RMWcc() macros
locking/qspinlock: Rework some comments
locking/qspinlock: Re-order code
locking/lockdep: Remove duplicated 'lock_class_ops' percpu array
x86/defconfig: Enable CONFIG_USB_XHCI_HCD=y
futex: Replace spin_is_locked() with lockdep
locking/lockdep: Make class->ops a percpu counter and move it under CONFIG_DEBUG_LOCKDEP=y
x86/jump-labels: Macrofy inline assembly code to work around GCC inlining bugs
x86/cpufeature: Macrofy inline assembly code to work around GCC inlining bugs
x86/extable: Macrofy inline assembly code to work around GCC inlining bugs
x86/paravirt: Work around GCC inlining bugs when compiling paravirt ops
x86/bug: Macrofy the BUG table section handling, to work around GCC inlining bugs
x86/alternatives: Macrofy lock prefixes to work around GCC inlining bugs
x86/refcount: Work around GCC inlining bug
x86/objtool: Use asm macros to work around GCC inlining bugs
...
Pull EFI updates from Ingo Molnar:
"The main changes are:
- Add support for enlisting the help of the EFI firmware to create
memory reservations that persist across kexec.
- Add page fault handling to the runtime services support code on x86
so we can more gracefully recover from buggy EFI firmware.
- Fix command line handling on x86 for the boot path that omits the
stub's PE/COFF entry point.
- Other assorted fixes and updates"
* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86: boot: Fix EFI stub alignment
efi/x86: Call efi_parse_options() from efi_main()
efi/x86: earlyprintk - Add 64bit efi fb address support
efi/x86: drop task_lock() from efi_switch_mm()
efi/x86: Handle page faults occurring while running EFI runtime services
efi: Make efi_rts_work accessible to efi page fault handler
efi/efi_test: add exporting ResetSystem runtime service
efi/libstub: arm: support building with clang
efi: add API to reserve memory persistently across kexec reboot
efi/arm: libstub: add a root memreserve config table
efi: honour memory reservations passed via a linux specific config table
PCI BIOS requires the BIOS area 0x0A0000-0x0FFFFFF to be mapped W+X for
various legacy reasons. When CONFIG_DEBUG_WX is enabled, this triggers the
WX warning, but this is misleading because the mapping is required and is
not a result of an accidental oversight.
Prevent the full warning when PCI BIOS is enabled and the detected WX
mapping is in the BIOS area. Just emit a pr_warn() which denotes the
fact. This is partially duplicating the info which the PCI BIOS code emits
when it maps the area as executable, but that info is not in the context of
the WX checking output.
Remove the extra %p printout in the WARN_ONCE() while at it. %pS is enough.
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Borislav Petkov <bp@suse.de>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1810082151160.2455@nanos.tec.linutronix.de
Spurious faults only ever occur in the kernel's address space. They
are also constrained specifically to faults with one of these error codes:
X86_PF_WRITE | X86_PF_PROT
X86_PF_INSTR | X86_PF_PROT
So, it's never even possible to reach spurious_kernel_fault_check() with
X86_PF_PK set.
In addition, the kernel's address space never has pages with user-mode
protections. Protection Keys are only enforced on pages with user-mode
protection.
This gives us lots of reasons to not check for protection keys in our
sprurious kernel fault handling.
But, let's also add some warnings to ensure that these assumptions about
protection keys hold true.
Cc: x86@kernel.org
Cc: Jann Horn <jannh@google.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180928160231.243A0D6A@viggo.jf.intel.com
The vsyscall page is weird. It is in what is traditionally part of
the kernel address space. But, it has user permissions and we handle
faults on it like we would on a user page: interrupts on.
Right now, we handle vsyscall emulation in the "bad_area" code, which
is used for both user-address-space and kernel-address-space faults.
Move the handling to the user-address-space code *only* and ensure we
get there by "excluding" the vsyscall page from the kernel address
space via a check in fault_in_kernel_space().
Since the fault_in_kernel_space() check is used on 32-bit, also add a
64-bit check to make it clear we only use this path on 64-bit. Also
move the unlikely() to be in is_vsyscall_vaddr() itself.
This helps clean up the kernel fault handling path by removing a case
that can happen in normal[1] operation. (Yeah, yeah, we can argue
about the vsyscall page being "normal" or not.) This also makes
sanity checks easier, like the "we never take pkey faults in the
kernel address space" check in the next patch.
Cc: x86@kernel.org
Cc: Jann Horn <jannh@google.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180928160230.6E9336EE@viggo.jf.intel.com
The page fault handler (__do_page_fault()) basically has two sections:
one for handling faults in the kernel portion of the address space
and another for faults in the user portion of the address space.
But, these two parts don't stick out that well. Let's make that more
clear from code separation and naming. Pull kernel fault
handling into its own helper, and reflect that naming by renaming
spurious_fault() -> spurious_kernel_fault().
Also, rewrite the vmalloc() handling comment a bit. It was a bit
stale and also glossed over the reserved bit handling.
Cc: x86@kernel.org
Cc: Jann Horn <jannh@google.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180928160222.401F4E10@viggo.jf.intel.com
We pass around a variable called "error_code" all around the page
fault code. Sounds simple enough, especially since "error_code" looks
like it exactly matches the values that the hardware gives us on the
stack to report the page fault error code (PFEC in SDM parlance).
But, that's not how it works.
For part of the page fault handler, "error_code" does exactly match
PFEC. But, during later parts, it diverges and starts to mean
something a bit different.
Give it two names for its two jobs.
The place it diverges is also really screwy. It's only in a spot
where the hardware tells us we have kernel-mode access that occurred
while we were in usermode accessing user-controlled address space.
Add a warning in there.
Cc: x86@kernel.org
Cc: Jann Horn <jannh@google.com>
Cc: Sean Christopherson <sean.j.christopherson@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180928160220.4A2272C9@viggo.jf.intel.com
Lazy TLB mode can result in an idle CPU being woken up by a TLB flush,
when all it really needs to do is reload %CR3 at the next context switch,
assuming no page table pages got freed.
Memory ordering is used to prevent race conditions between switch_mm_irqs_off,
which checks whether .tlb_gen changed, and the TLB invalidation code, which
increments .tlb_gen whenever page table entries get invalidated.
The atomic increment in inc_mm_tlb_gen is its own barrier; the context
switch code adds an explicit barrier between reading tlbstate.is_lazy and
next->context.tlb_gen.
CPUs in lazy TLB mode remain part of the mm_cpumask(mm), both because
that allows TLB flush IPIs to be sent at page table freeing time, and
because the cache line bouncing on the mm_cpumask(mm) was responsible
for about half the CPU use in switch_mm_irqs_off().
We can change native_flush_tlb_others() without touching other
(paravirt) implementations of flush_tlb_others() because we'll be
flushing less. The existing implementations flush more and are
therefore still correct.
Cc: npiggin@gmail.com
Cc: mingo@kernel.org
Cc: will.deacon@arm.com
Cc: kernel-team@fb.com
Cc: luto@kernel.org
Cc: hpa@zytor.com
Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180926035844.1420-8-riel@surriel.com
Arnd Bergmann reported that turning on -Wvla found a new (unintended) VLA usage:
arch/x86/mm/pgtable.c: In function 'pgd_alloc':
include/linux/build_bug.h:29:45: error: ISO C90 forbids variable length array 'u_pmds' [-Werror=vla]
arch/x86/mm/pgtable.c:190:34: note: in expansion of macro 'static_cpu_has'
#define PREALLOCATED_USER_PMDS (static_cpu_has(X86_FEATURE_PTI) ? \
^~~~~~~~~~~~~~
arch/x86/mm/pgtable.c:431:16: note: in expansion of macro 'PREALLOCATED_USER_PMDS'
pmd_t *u_pmds[PREALLOCATED_USER_PMDS];
^~~~~~~~~~~~~~~~~~~~~~
Use the actual size of the array that is used for X86_FEATURE_PTI,
which is known at build time, instead of the variable size.
[ mingo: Squashed original fix with followup fix to avoid bisection breakage, wrote new changelog. ]
Reported-by: Arnd Bergmann <arnd@arndb.de>
Original-written-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Joerg Roedel <jroedel@suse.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hpe.com>
Fixes: 1be3f247c288 ("x86/mm: Avoid VLA in pgd_alloc()")
Link: http://lkml.kernel.org/r/20181008235434.GA35035@beast
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When SME is enabled, the memory is encrypted in the first kernel. In
this case, SME also needs to be enabled in the kdump kernel, and we have
to remap the old memory with the memory encryption mask.
The case of concern here is if SME is active in the first kernel,
and it is active too in the kdump kernel. There are four cases to be
considered:
a. dump vmcore
It is encrypted in the first kernel, and needs be read out in the
kdump kernel.
b. crash notes
When dumping vmcore, the people usually need to read useful
information from notes, and the notes is also encrypted.
c. iommu device table
It's encrypted in the first kernel, kdump kernel needs to access its
content to analyze and get information it needs.
d. mmio of AMD iommu
not encrypted in both kernels
Add a new bool parameter @encrypted to __ioremap_caller(). If set,
memory will be remapped with the SME mask.
Add a new function ioremap_encrypted() to explicitly pass in a true
value for @encrypted. Use ioremap_encrypted() for the above a, b, c
cases.
[ bp: cleanup commit message, extern defs in io.h and drop forgotten
include. ]
Signed-off-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: kexec@lists.infradead.org
Cc: tglx@linutronix.de
Cc: mingo@redhat.com
Cc: hpa@zytor.com
Cc: akpm@linux-foundation.org
Cc: dan.j.williams@intel.com
Cc: bhelgaas@google.com
Cc: baiyaowei@cmss.chinamobile.com
Cc: tiwai@suse.de
Cc: brijesh.singh@amd.com
Cc: dyoung@redhat.com
Cc: bhe@redhat.com
Cc: jroedel@suse.de
Link: https://lkml.kernel.org/r/20180927071954.29615-2-lijiang@redhat.com
The extra loop which tries hard to preserve large pages in case of conflicts
with static protection regions turns out to be not preserving anything, at
least not in the experiments which have been conducted.
There might be corner cases in which the code would be able to preserve a
large page oaccsionally, but it's really not worth the extra code and the
cycles wasted in the common case.
Before:
1G pages checked: 2
1G pages sameprot: 0
1G pages preserved: 0
2M pages checked: 541
2M pages sameprot: 466
2M pages preserved: 47
4K pages checked: 514
4K pages set-checked: 7668
After:
1G pages checked: 2
1G pages sameprot: 0
1G pages preserved: 0
2M pages checked: 538
2M pages sameprot: 466
2M pages preserved: 47
4K pages set-checked: 7668
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bin Yang <bin.yang@intel.com>
Cc: Mark Gross <mark.gross@intel.com>
Link: https://lkml.kernel.org/r/20180917143546.589642503@linutronix.de
To avoid excessive 4k wise checks in the common case do a quick check first
whether the requested new page protections conflict with a static
protection area in the large page. If there is no conflict then the
decision whether to preserve or to split the page can be made immediately.
If the requested range covers the full large page, preserve it. Otherwise
split it up. No point in doing a slow crawl in 4k steps.
Before:
1G pages checked: 2
1G pages sameprot: 0
1G pages preserved: 0
2M pages checked: 538
2M pages sameprot: 466
2M pages preserved: 47
4K pages checked: 560642
4K pages set-checked: 7668
After:
1G pages checked: 2
1G pages sameprot: 0
1G pages preserved: 0
2M pages checked: 541
2M pages sameprot: 466
2M pages preserved: 47
4K pages checked: 514
4K pages set-checked: 7668
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bin Yang <bin.yang@intel.com>
Cc: Mark Gross <mark.gross@intel.com>
Link: https://lkml.kernel.org/r/20180917143546.507259989@linutronix.de
When the existing mapping is correct and the new requested page protections
are the same as the existing ones, then further checks can be omitted and the
large page can be preserved. The slow path 4k wise check will not come up with
a different result.
Before:
1G pages checked: 2
1G pages sameprot: 0
1G pages preserved: 0
2M pages checked: 540
2M pages sameprot: 466
2M pages preserved: 47
4K pages checked: 800709
4K pages set-checked: 7668
After:
1G pages checked: 2
1G pages sameprot: 0
1G pages preserved: 0
2M pages checked: 538
2M pages sameprot: 466
2M pages preserved: 47
4K pages checked: 560642
4K pages set-checked: 7668
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bin Yang <bin.yang@intel.com>
Cc: Mark Gross <mark.gross@intel.com>
Link: https://lkml.kernel.org/r/20180917143546.424477581@linutronix.de
With the range check it is possible to do a quick verification that the
current mapping is correct vs. the static protection areas.
In case a incorrect mapping is detected a warning is emitted and the large
page is split up. If the large page is a 2M page, then the split code is
forced to check the static protections for the PTE entries to fix up the
incorrectness. For 1G pages this can't be done easily because that would
require to either find the offending 2M areas before the split or
afterwards. For now just warn about that case and revisit it when reported.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bin Yang <bin.yang@intel.com>
Cc: Mark Gross <mark.gross@intel.com>
Link: https://lkml.kernel.org/r/20180917143546.331408643@linutronix.de
The large page preservation mechanism is just magic and provides no
information at all. Add optional statistic output in debugfs so the magic can
be evaluated. Defaults is off.
Output:
1G pages checked: 2
1G pages sameprot: 0
1G pages preserved: 0
2M pages checked: 540
2M pages sameprot: 466
2M pages preserved: 47
4K pages checked: 800770
4K pages set-checked: 7668
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bin Yang <bin.yang@intel.com>
Cc: Mark Gross <mark.gross@intel.com>
Link: https://lkml.kernel.org/r/20180917143546.160867778@linutronix.de
The whole static protection magic is silently fixing up anything which is
handed in. That's just wrong. The offending call sites need to be fixed.
Add a debug mechanism which emits a warning if a requested mapping needs to be
fixed up. The DETECT debug mechanism is really not meant to be enabled except
for developers, so limit the output hard to the protection fixups.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bin Yang <bin.yang@intel.com>
Cc: Mark Gross <mark.gross@intel.com>
Link: https://lkml.kernel.org/r/20180917143546.078998733@linutronix.de
The sequence of marking text and rodata read-only in 32bit init is:
set_ro(text);
kernel_set_to_readonly = 1;
set_ro(rodata);
When kernel_set_to_readonly is 1 it enables the protection mechanism in CPA
for the read only regions. With the upcoming checks for existing mappings
this consequently triggers the warning about an existing mapping being
incorrect vs. static protections because rodata has not been converted yet.
There is no technical reason to split the two, so just combine the RO
protection to convert text and rodata in one go.
Convert the printks to pr_info while at it.
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Bin Yang <bin.yang@intel.com>
Cc: Mark Gross <mark.gross@intel.com>
Link: https://lkml.kernel.org/r/20180917143545.731701535@linutronix.de
Pull EFI updates for v4.20 from Ard Biesheuvel:
- Add support for enlisting the help of the EFI firmware to create memory
reservations that persist across kexec.
- Add page fault handling to the runtime services support code on x86 so
we can gracefully recover from buggy EFI firmware.
- Fix command line handling on x86 for the boot path that omits the stub's
PE/COFF entry point.
- Other assorted fixes.
Currently, IBPB is only issued in cases when switching into a non-dumpable
process, the rationale being to protect such 'important and security
sensitive' processess (such as GPG) from data leaking into a different
userspace process via spectre v2.
This is however completely insufficient to provide proper userspace-to-userpace
spectrev2 protection, as any process can poison branch buffers before being
scheduled out, and the newly scheduled process immediately becomes spectrev2
victim.
In order to minimize the performance impact (for usecases that do require
spectrev2 protection), issue the barrier only in cases when switching between
processess where the victim can't be ptraced by the potential attacker (as in
such cases, the attacker doesn't have to bother with branch buffers at all).
[ tglx: Split up PTRACE_MODE_NOACCESS_CHK into PTRACE_MODE_SCHED and
PTRACE_MODE_IBPB to be able to do ptrace() context tracking reasonably
fine-grained ]
Fixes: 18bf3c3ea8 ("x86/speculation: Use Indirect Branch Prediction Barrier in context switch")
Originally-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "WoodhouseDavid" <dwmw@amazon.co.uk>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: "SchauflerCasey" <casey.schaufler@intel.com>
Link: https://lkml.kernel.org/r/nycvar.YFH.7.76.1809251437340.15880@cbobk.fhfr.pm
Memory accesses performed by UEFI runtime services should be limited to:
- reading/executing from EFI_RUNTIME_SERVICES_CODE memory regions
- reading/writing from/to EFI_RUNTIME_SERVICES_DATA memory regions
- reading/writing by-ref arguments
- reading/writing from/to the stack.
Accesses outside these regions may cause the kernel to hang because the
memory region requested by the firmware isn't mapped in efi_pgd, which
causes a page fault in ring 0 and the kernel fails to handle it, leading
to die(). To save kernel from hanging, add an EFI specific page fault
handler which recovers from such faults by
1. If the efi runtime service is efi_reset_system(), reboot the machine
through BIOS.
2. If the efi runtime service is _not_ efi_reset_system(), then freeze
efi_rts_wq and schedule a new process.
The EFI page fault handler offers us two advantages:
1. Avoid potential hangs caused by buggy firmware.
2. Shout loud that the firmware is buggy and hence is not a kernel bug.
Tested-by: Bhupesh Sharma <bhsharma@redhat.com>
Suggested-by: Matt Fleming <matt@codeblueprint.co.uk>
Based-on-code-from: Ricardo Neri <ricardo.neri@intel.com>
Signed-off-by: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
[ardb: clarify commit log]
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Now that si_code == SEGV_PKUERR is the flag indicating that a pkey
is present there is no longer a need to pass a pointer to a local
pkey value, instead pkey can be passed more efficiently by value.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Now that the pkey handling has been removed force_sig_info_fault and
force_sig_fault perform identical work. Just the type of the address
paramter is different. So replace calls to force_sig_info_fault with
calls to force_sig_fault, and remove force_sig_info_fault.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
There is only one code path that can generate a pkuerr signal. That
code path calls __bad_area_nosemaphore and can be dectected by testing
if si_code == SEGV_PKUERR. It can be seen from inspection that all of
the other tests in fill_sig_info_pkey are unnecessary.
Therefore call force_sig_pkuerr directly from __bad_area_semaphore and
remove fill_sig_info_pkey.
At the same time move the comment above force_sig_info_pkey into
bad_area_access_error, so that the documentation about pkey generation
races is not lost.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
There is only one caller of __bad_area that passes in PKUERR and thus
will generate a siginfo with si_pkey set. Therefore simplify the
logic and hoist reading of vma_pkey up into that caller, and just
pass *pkey into __bad_area.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
There are no more users of the computed pkey value in __do_page_fault
so stop computing the value.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
After the previous cleanups to do_sigbus and and bad_area_nosemaphore
mm_fault_error no now longer uses it's pkey parameter. Therefore
remove the unused parameter.
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
