For more control over which functions are called with the MMU off or
with the UEFI 1:1 mapping active, annotate some assembler routines as
position independent. This is done by introducing ENDPIPROC(), which
replaces the ENDPROC() declaration of those routines.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
A prior commit used to detect the hw breakpoint ABI behaviour based on
the target state missed the asm/compat.h include and the build fails
with !CONFIG_COMPAT.
Fixes: 8f48c06290 ("arm64: hw_breakpoint: use target state to determine ABI behaviour")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When cpu is disabled, all irqs will be migratged to another cpu.
In some cases, a new affinity is different, the old affinity need
to be updated and if irq_set_affinity's return value is IRQ_SET_MASK_OK_DONE,
the old affinity can not be updated. Fix it by using irq_do_set_affinity.
And migrating interrupts is a core code matter, so use the generic
function irq_migrate_all_off_this_cpu() to migrate interrupts in
kernel/irq/migration.c.
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Hanjun Guo <hanjun.guo@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
With 64k pages, the next larger segment size is 512M. The linux
kernel also uses different protection flags to cover its code and data.
Because of this requirement, the vast majority of the kernel code and
data structures end up being mapped with 64k pages instead of the larger
pages common with a 4k page kernel.
Recent ARM processors support a contiguous bit in the
page tables which allows the a TLB to cover a range larger than a
single PTE if that range is mapped into physically contiguous
ram.
So, for the kernel its a good idea to set this flag. Some basic
micro benchmarks show it can significantly reduce the number of
L1 dTLB refills.
Add boot option to enable/disable CONT marking, as well as fix a
bug found by Steve Capper.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
[catalin.marinas@arm.com: remove CONFIG_ARM64_CONT_PTE altogether]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The kernel page dump utility needs to be aware of the CONT bit before
it will break up pages ranges for display.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The default page attributes for a PMD being broken should have the CONT bit
set. Create a new definition for an early boot range of PTE's that are
contiguous.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add the supporting macros to check if the contiguous bit
is set, set the bit, or clear it in a PTE entry.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Define the bit positions in the PTE and PMD for the
contiguous bit.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add the number of pages required to form a contiguous range,
as well as some supporting constants.
Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The A57 and A53 PMUs in Juno support different events, so describe them
separately in both the Juno and Juno R1 DTs.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The Cortex-A57 PMU supports a few events outside of the required PMUv3
set that are rather useful.
This patch adds the event map data for said events.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The Cortex-A53 PMU supports a few events outside of the required PMUv3
set that are rather useful.
This patch adds the event map data for said events.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Now that the arm_pmu framework has been factored out to drivers/perf we
can make use of it for arm64, gaining support for heterogeneous PMUs
and unifying the two codebases before they diverge further.
The as yet unused PMU name for PMUv3 is changed to armv8_pmuv3, matching
the style previously applied to the 32-bit PMUs.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The arm64 hw_breakpoint interface is slightly less flexible than its
32-bit counterpart, thanks to some changes in the architecture rendering
unaligned watchpoint addresses obselete for AArch64.
However, in a multi-arch environment (i.e. debugging a 32-bit target
with a 64-bit GDB under a 64-bit kernel), we need to provide a feature
compatible interface to GDB in order for debugging to function correctly.
This patch adds a new helper, is_compat_bp, to our hw_breakpoint
implementation which changes the interface behaviour based on the
architecture of the debug target as opposed to the debugger itself.
This allows debugged to function as expected for multi-arch
configurations without relying on deprecated architectural behaviours
when debugging native applications.
Cc: Yao Qi <yao.qi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
update_mmu_cache() consists of a dsb(ishst) instruction so that new user
mappings are guaranteed to be visible to the page table walker on
exception return.
In reality this can be a very expensive operation which is rarely needed.
Removing this barrier shows a modest improvement in hackbench scores and
, in the worst case, we re-take the user fault and establish that there
was nothing to do.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
__flush_tlb_pgtable is used to invalidate intermediate page table
entries after they have been cleared and are about to be freed. Since
pXd_clear imply memory barriers, we don't need the extra one here.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
mm_cpumask isn't actually used for anything on arm64, so remove all the
code trying to keep it up-to-date.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
switch_mm performs some checks to try and avoid entering the ASID
allocator:
(1) If we're switching to the init_mm (no user mappings), then simply
set a reserved TTBR0 value with no page table (the zero page)
(2) If prev == next *and* the mm_cpumask indicates that we've run on
this CPU before, then we can skip the allocator.
However, there is plenty of redundancy here. With the new ASID allocator,
if prev == next, then we know that our ASID is valid and do not need to
worry about re-allocation. Consequently, we can drop the mm_cpumask check
in (2) and move the prev == next check before the init_mm check, since
if prev == next == init_mm then there's nothing to do.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The TLB gather code sets fullmm=1 when tearing down the entire address
space for an mm_struct on exit or execve. Given that the ASID allocator
will never re-allocate a dirty ASID, this flushing is not needed and can
simply be avoided in the flushing code.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The ASID macro returns a 64-bit (long long) value, so there is no need
to cast to (unsigned long) before shifting prior to a TLBI operation.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Our current switch_mm implementation suffers from a number of problems:
(1) The ASID allocator relies on IPIs to synchronise the CPUs on a
rollover event
(2) Because of (1), we cannot allocate ASIDs with interrupts disabled
and therefore make use of a TIF_SWITCH_MM flag to postpone the
actual switch to finish_arch_post_lock_switch
(3) We run context switch with a reserved (invalid) TTBR0 value, even
though the ASID and pgd are updated atomically
(4) We take a global spinlock (cpu_asid_lock) during context-switch
(5) We use h/w broadcast TLB operations when they are not required
(e.g. in flush_context)
This patch addresses these problems by rewriting the ASID algorithm to
match the bitmap-based arch/arm/ implementation more closely. This in
turn allows us to remove much of the complications surrounding switch_mm,
including the ugly thread flag.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
There are a number of places where a single CPU is running with a
private page-table and we need to perform maintenance on the TLB and
I-cache in order to ensure correctness, but do not require the operation
to be broadcast to other CPUs.
This patch adds local variants of tlb_flush_all and __flush_icache_all
to support these use-cases and updates the callers respectively.
__local_flush_icache_all also implies an isb, since it is intended to be
used synchronously.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: David Daney <david.daney@cavium.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When cold-booting a CPU, we must invalidate any junk entries from the
local TLB prior to enabling the MMU. This doesn't require broadcasting
within the inner-shareable domain, so de-scope the operation to apply
only to the local CPU.
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
With commit b08d4640a3 ("arm64: remove dead code"),
cpu_set_idmap_tcr_t0sz is no longer called and can therefore be removed
from the kernel.
This patch removes the function and effectively inlines the helper
function __cpu_set_tcr_t0sz into cpu_set_default_tcr_t0sz.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In order to not use lengthy (UL(0xffffffffffffffff) << VA_BITS) everywhere,
replace it with VA_START.
Signed-off-by: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch optimize copy_to-from-in_user for arm 64bit architecture. The
copy template is used as template file for all the copy*.S files. Minor
change was made to it to accommodate the copy to/from/in user files.
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This converts the memcpy.S to use the copy template file. The copy
template file was based originally on the memcpy.S
Signed-off-by: Feng Kan <fkan@apm.com>
Signed-off-by: Balamurugan Shanmugam <bshanmugam@apm.com>
[catalin.marinas@arm.com: removed tmp3(w) .req statements as they are not used]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This patch update defconfig, adds samsung serial and
Synopsys Designware MMC configs related to exynos SoC
Signed-off-by: Alim Akhtar <alim.akhtar@samsung.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Pull strscpy string copy function implementation from Chris Metcalf.
Chris sent this during the merge window, but I waffled back and forth on
the pull request, which is why it's going in only now.
The new "strscpy()" function is definitely easier to use and more secure
than either strncpy() or strlcpy(), both of which are horrible nasty
interfaces that have serious and irredeemable problems.
strncpy() has a useless return value, and doesn't NUL-terminate an
overlong result. To make matters worse, it pads a short result with
zeroes, which is a performance disaster if you have big buffers.
strlcpy(), by contrast, is a mis-designed "fix" for strlcpy(), lacking
the insane NUL padding, but having a differently broken return value
which returns the original length of the source string. Which means
that it will read characters past the count from the source buffer, and
you have to trust the source to be properly terminated. It also makes
error handling fragile, since the test for overflow is unnecessarily
subtle.
strscpy() avoids both these problems, guaranteeing the NUL termination
(but not excessive padding) if the destination size wasn't zero, and
making the overflow condition very obvious by returning -E2BIG. It also
doesn't read past the size of the source, and can thus be used for
untrusted source data too.
So why did I waffle about this for so long?
Every time we introduce a new-and-improved interface, people start doing
these interminable series of trivial conversion patches.
And every time that happens, somebody does some silly mistake, and the
conversion patch to the improved interface actually makes things worse.
Because the patch is mindnumbing and trivial, nobody has the attention
span to look at it carefully, and it's usually done over large swatches
of source code which means that not every conversion gets tested.
So I'm pulling the strscpy() support because it *is* a better interface.
But I will refuse to pull mindless conversion patches. Use this in
places where it makes sense, but don't do trivial patches to fix things
that aren't actually known to be broken.
* 'strscpy' of git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
tile: use global strscpy() rather than private copy
string: provide strscpy()
Make asm/word-at-a-time.h available on all architectures
Pull MIPS updates from Ralf Baechle:
"This week's round of MIPS fixes:
- Fix JZ4740 build
- Fix fallback to GFP_DMA
- FP seccomp in case of ENOSYS
- Fix bootmem panic
- A number of FP and CPS fixes
- Wire up new syscalls
- Make sure BPF assembler objects can properly be disassembled
- Fix BPF assembler code for MIPS I"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus:
MIPS: scall: Always run the seccomp syscall filters
MIPS: Octeon: Fix kernel panic on startup from memory corruption
MIPS: Fix R2300 FP context switch handling
MIPS: Fix octeon FP context switch handling
MIPS: BPF: Fix load delay slots.
MIPS: BPF: Do all exports of symbols with FEXPORT().
MIPS: Fix the build on jz4740 after removing the custom gpio.h
MIPS: CPS: #ifdef on CONFIG_MIPS_MT_SMP rather than CONFIG_MIPS_MT
MIPS: CPS: Don't include MT code in non-MT kernels.
MIPS: CPS: Stop dangling delay slot from has_mt.
MIPS: dma-default: Fix 32-bit fall back to GFP_DMA
MIPS: Wire up userfaultfd and membarrier syscalls.
The MIPS syscall handler code used to return -ENOSYS on invalid
syscalls. Whilst this is expected, it caused problems for seccomp
filters because the said filters never had the change to run since
the code returned -ENOSYS before triggering them. This caused
problems on the chromium testsuite for filters looking for invalid
syscalls. This has now changed and the seccomp filters are always
run even if the syscall is invalid. We return -ENOSYS once we
return from the seccomp filters. Moreover, similar codepaths have
been merged in the process which simplifies somewhat the overall
syscall code.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/11236/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Pull x86 fixes from Ingo Molnar:
"Fixes all around the map: W+X kernel mapping fix, WCHAN fixes, two
build failure fixes for corner case configs, x32 header fix and a
speling fix"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/headers/uapi: Fix __BITS_PER_LONG value for x32 builds
x86/mm: Set NX on gap between __ex_table and rodata
x86/kexec: Fix kexec crash in syscall kexec_file_load()
x86/process: Unify 32bit and 64bit implementations of get_wchan()
x86/process: Add proper bound checks in 64bit get_wchan()
x86, efi, kasan: Fix build failure on !KASAN && KMEMCHECK=y kernels
x86/hyperv: Fix the build in the !CONFIG_KEXEC_CORE case
x86/cpufeatures: Correct spelling of the HWP_NOTIFY flag
Pull EFI fixes from Ingo Molnar:
"Two EFI fixes: one for x86, one for ARM, fixing a boot crash bug that
can trigger under newer EFI firmware"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
arm64/efi: Fix boot crash by not padding between EFI_MEMORY_RUNTIME regions
x86/efi: Fix boot crash by mapping EFI memmap entries bottom-up at runtime, instead of top-down
inadvertently changing a huge pmd page into a pmd table entry.
- Function graph tracer panic fix caused by the return_to_handler code
corrupting the multi-regs function return value (composite types).
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Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Catalin Marinas:
- Fix for transparent huge page change_protection() logic which was
inadvertently changing a huge pmd page into a pmd table entry.
- Function graph tracer panic fix caused by the return_to_handler code
corrupting the multi-regs function return value (composite types).
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
arm64: ftrace: fix function_graph tracer panic
arm64: Fix THP protection change logic
Pull m68k updates from Geert Uytterhoeven:
"Summary:
- Fix for accidental modification of arguments of syscall functions
- Wire up new syscalls
- Update defconfigs"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k/defconfig: Update defconfigs for v4.3-rc1
m68k: Define asmlinkage_protect
m68k: Wire up membarrier
m68k: Wire up userfaultfd
m68k: Wire up direct socket calls
During development it was found that a number of builds would panic
during the kernel init process, more specifically in 'delayed_fput()'.
The panic showed the kernel trying to access a memory address of
'0xb7fdc00' while traversing the 'delayed_fput_list' structure.
Comparing this memory address to the value of the pointer used on
builds that did not panic confirmed that the pointer on crashing
builds must have been corrupted at some stage earlier in the init
process.
By traversing the list earlier and earlier in the code it was found
that 'plat_mem_setup()' was responsible for corrupting the list.
Specifically the line:
memory = cvmx_bootmem_phy_alloc(mem_alloc_size,
__pa_symbol(&__init_end), -1,
0x100000,
CVMX_BOOTMEM_FLAG_NO_LOCKING);
Which would eventually call:
cvmx_bootmem_phy_set_size(new_ent_addr,
cvmx_bootmem_phy_get_size
(ent_addr) -
(desired_min_addr -
ent_addr));
Where 'new_ent_addr'=0x4800000 (the address of 'delayed_fput_list')
and the second argument (size)=0xb7fdc00 (the address causing the
kernel panic). The job of this part of 'plat_mem_setup()' is to
allocate chunks of memory for the kernel to use. At the start of
each chunk of memory the size of the chunk is written, hence the
value 0xb7fdc00 is written onto memory at 0x4800000, therefore the
kernel panics when it goes back to access 'delayed_fput_list' later
on in the initialisation process.
On builds that were not crashing it was found that the compiler had
placed 'delayed_fput_list' at 0x4800008, meaning it wasn't corrupted
(but something else in memory was overwritten).
As can be seen in the first function call above the code begins to
allocate chunks of memory beginning from the symbol '__init_end'.
The MIPS linker script (vmlinux.lds.S) however defines the .bss
section to begin after '__init_end'. Therefore memory within the
.bss section is allocated to the kernel to use (System.map shows
'delayed_fput_list' and other kernel structures to be in .bss).
To stop the kernel panic (and the .bss section being corrupted)
memory should begin being allocated from the symbol '_end'.
Signed-off-by: Matt Bennett <matt.bennett@alliedtelesis.co.nz>
Acked-by: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: aleksey.makarov@auriga.com
Patchwork: https://patchwork.linux-mips.org/patch/11251/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Commit 1a3d59579b ("MIPS: Tidy up FPU context switching") removed FP
context saving from the asm-written resume function in favour of reusing
existing code to perform the same task. However it only removed the FP
context saving code from the r4k_switch.S implementation of resume.
Remove it from the r2300_switch.S implementation too in order to prevent
attempting to save the FP context twice, which would likely lead to an
exception from the second save because the FPU had already been disabled
by the first save.
This patch has only been build tested, using rbtx49xx_defconfig.
Fixes: 1a3d59579b ("MIPS: Tidy up FPU context switching")
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Cc: linux-kernel@vger.kernel.org
Cc: Manuel Lauss <manuel.lauss@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/11167/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The entire bpf_jit_asm.S is written in noreorder mode because "we know
better" according to a comment. This also prevented the assembler from
throwing in the required NOPs for MIPS I processors which have no
load-use interlock, thus the load's consumer might end up using the
old value of the register from prior to the load.
Fixed by putting the assembler in reorder mode for just the affected
load instructions. This is not enough for gas to actually try to be
clever by looking at the next instruction and inserting a nop only
when needed but as the comment said "we know better", so getting gas
to unconditionally emit a NOP is just right in this case and prevents
adding further ifdefery.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
On x32, gcc predefines __x86_64__ but long is only 32-bit. Use
__ILP32__ to distinguish x32.
Fixes this compiler error in perf:
tools/include/asm-generic/bitops/__ffs.h: In function '__ffs':
tools/include/asm-generic/bitops/__ffs.h:19:8: error: right shift count >= width of type [-Werror=shift-count-overflow]
word >>= 32;
^
This isn't sufficient to build perf for x32, though.
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: 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
Link: http://lkml.kernel.org/r/1443660043.2730.15.camel@decadent.org.uk
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Unused space between the end of __ex_table and the start of
rodata can be left W+x in the kernel page tables. Extend the
setting of the NX bit to cover this gap by starting from
text_end rather than rodata_start.
Before:
---[ High Kernel Mapping ]---
0xffffffff80000000-0xffffffff81000000 16M pmd
0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd
0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte
0xffffffff81754000-0xffffffff81800000 688K RW GLB x pte
0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd
0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte
0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte
0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd
0xffffffff82200000-0xffffffffa0000000 478M pmd
After:
---[ High Kernel Mapping ]---
0xffffffff80000000-0xffffffff81000000 16M pmd
0xffffffff81000000-0xffffffff81600000 6M ro PSE GLB x pmd
0xffffffff81600000-0xffffffff81754000 1360K ro GLB x pte
0xffffffff81754000-0xffffffff81800000 688K RW GLB NX pte
0xffffffff81800000-0xffffffff81a00000 2M ro PSE GLB NX pmd
0xffffffff81a00000-0xffffffff81b3b000 1260K ro GLB NX pte
0xffffffff81b3b000-0xffffffff82000000 4884K RW GLB NX pte
0xffffffff82000000-0xffffffff82200000 2M RW PSE GLB NX pmd
0xffffffff82200000-0xffffffffa0000000 478M pmd
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Cc: 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
Link: http://lkml.kernel.org/r/1443704662-3138-1-git-send-email-sds@tycho.nsa.gov
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The original bug is a page fault crash that sometimes happens
on big machines when preparing ELF headers:
BUG: unable to handle kernel paging request at ffffc90613fc9000
IP: [<ffffffff8103d645>] prepare_elf64_ram_headers_callback+0x165/0x260
The bug is caused by us under-counting the number of memory ranges
and subsequently not allocating enough ELF header space for them.
The bug is typically masked on smaller systems, because the ELF header
allocation is rounded up to the next page.
This patch modifies the code in fill_up_crash_elf_data() by using
walk_system_ram_res() instead of walk_system_ram_range() to correctly
count the max number of crash memory ranges. That's because the
walk_system_ram_range() filters out small memory regions that
reside in the same page, but walk_system_ram_res() does not.
Here's how I found the bug:
After tracing prepare_elf64_headers() and prepare_elf64_ram_headers_callback(),
the code uses walk_system_ram_res() to fill-in crash memory regions information
to the program header, so it counts those small memory regions that
reside in a page area.
But, when the kernel was using walk_system_ram_range() in
fill_up_crash_elf_data() to count the number of crash memory regions,
it filters out small regions.
I printed those small memory regions, for example:
kexec: Get nr_ram ranges. vaddr=0xffff880077592258 paddr=0x77592258, sz=0xdc0
Based on the code in walk_system_ram_range(), this memory region
will be filtered out:
pfn = (0x77592258 + 0x1000 - 1) >> 12 = 0x77593
end_pfn = (0x77592258 + 0xfc0 -1 + 1) >> 12 = 0x77593
end_pfn - pfn = 0x77593 - 0x77593 = 0 <=== if (end_pfn > pfn) is FALSE
So, the max_nr_ranges that's counted by the kernel doesn't include
small memory regions - causing us to under-allocate the required space.
That causes the page fault crash that happens in a later code path
when preparing ELF headers.
This bug is not easy to reproduce on small machines that have few
CPUs, because the allocated page aligned ELF buffer has more free
space to cover those small memory regions' PT_LOAD headers.
Signed-off-by: Lee, Chun-Yi <jlee@suse.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Takashi Iwai <tiwai@suse.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: kexec@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/1443531537-29436-1-git-send-email-jlee@suse.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge misc fixes from Andrew Morton:
"12 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
dmapool: fix overflow condition in pool_find_page()
thermal: avoid division by zero in power allocator
memcg: remove pcp_counter_lock
kprobes: use _do_fork() in samples to make them work again
drivers/input/joystick/Kconfig: zhenhua.c needs BITREVERSE
memcg: make mem_cgroup_read_stat() unsigned
memcg: fix dirty page migration
dax: fix NULL pointer in __dax_pmd_fault()
mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a fault
mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1)
userfaultfd: remove kernel header include from uapi header
arch/x86/include/asm/efi.h: fix build failure
Bugs have trickled in for a new feature in 4.2 (MTRR support in guests)
so I'm reverting it all; let's not make this -rc period busier for KVM
than it's been so far. This covers the four reverts from me.
The fifth patch is being reverted because Radim found a bug in the
implementation of stable scheduler clock, *but* also managed to implement
the feature entirely without hypervisor support. So instead of fixing
the hypervisor side we can remove it completely; 4.4 will get the new
implementation.
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"(Relatively) a lot of reverts, mostly.
Bugs have trickled in for a new feature in 4.2 (MTRR support in
guests) so I'm reverting it all; let's not make this -rc period busier
for KVM than it's been so far. This covers the four reverts from me.
The fifth patch is being reverted because Radim found a bug in the
implementation of stable scheduler clock, *but* also managed to
implement the feature entirely without hypervisor support. So instead
of fixing the hypervisor side we can remove it completely; 4.4 will
get the new implementation"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
Use WARN_ON_ONCE for missing X86_FEATURE_NRIPS
Update KVM homepage Url
Revert "KVM: SVM: use NPT page attributes"
Revert "KVM: svm: handle KVM_X86_QUIRK_CD_NW_CLEARED in svm_get_mt_mask"
Revert "KVM: SVM: Sync g_pat with guest-written PAT value"
Revert "KVM: x86: apply guest MTRR virtualization on host reserved pages"
Revert "KVM: x86: zero kvmclock_offset when vcpu0 initializes kvmclock system MSR"
6910fa1 ("arm64: enable PTE type bit in the mask for pte_modify") fixes
a problem whereby a large block of PROT_NONE mapped memory is
incorrectly mapped as block descriptors when mprotect is called.
Unfortunately, a subtle bug was introduced by this fix to the THP logic.
If one mmaps a large block of memory, then faults it such that it is
collapsed into THPs; resulting calls to mprotect on this area of memory
will lead to incorrect table descriptors being written instead of block
descriptors. This is because pmd_modify calls pte_modify which is now
allowed to modify the type of the page table entry.
This patch reverts commit 6910fa16db, and
fixes the problem it was trying to address by adjusting PAGE_NONE to
represent a table entry. Thus no change in pte type is required when
moving from PROT_NONE to a different protection.
Fixes: 6910fa16db ("arm64: enable PTE type bit in the mask for pte_modify")
Cc: <stable@vger.kernel.org> # 4.0+
Cc: Feng Kan <fkan@apm.com>
Reported-by: Ganapatrao Kulkarni <Ganapatrao.Kulkarni@caviumnetworks.com>
Tested-by: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
FEXPORT also marks the symbol as code using .type symbol, @function.
Without objdump -d will output only a hexdump for code following the
affected symbols.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The cpu feature flags are not ever going to change, so warning
everytime can cause a lot of kernel log spam
(in our case more than 10GB/hour).
The warning seems to only occur when nested virtualization is
enabled, so it's probably triggered by a KVM bug. This is a
sensible and safe change anyway, and the KVM bug fix might not
be suitable for stable releases anyway.
Cc: stable@vger.kernel.org
Signed-off-by: Dirk Mueller <dmueller@suse.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This reverts commit 3c2e7f7de3.
Initializing the mapping from MTRR to PAT values was reported to
fail nondeterministically, and it also caused extremely slow boot
(due to caching getting disabled---bug 103321) with assigned devices.
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reported-by: Sebastian Schuette <dracon@ewetel.net>
Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Ard Biesheuvel
Catalin Marinas
Yang Yingliang
Jeremy Linton
Mark Rutland
Will Deacon
Andrey Ryabinin
Feng Kan
Alim Akhtar
Linus Torvalds
Markos Chandras
Matt Bennett
Paul Burton
Li Bin
Ralf Baechle
Ben Hutchings
Stephen Smalley
Lee, Chun-Yi
Steve Capper
Dirk Müller
Paolo Bonzini