| Age | Commit message (Collapse) | Author |
|---|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fpu updates from Ingo Molnar:
"Initial round of kernel_fpu_begin/end cleanups from Oleg Nesterov,
plus a cleanup from Borislav Petkov"
* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, fpu: Fix math_state_restore() race with kernel_fpu_begin()
x86, fpu: Don't abuse has_fpu in __kernel_fpu_begin/end()
x86, fpu: Introduce per-cpu in_kernel_fpu state
x86/fpu: Use a symbolic name for asm operand
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull EFI updates from Ingo Molnar:
"Main changes:
- Move efivarfs from the misc filesystem section to pseudo filesystem
- Expose firmware platform size in sysfs
- Improve robustness of get_memory_map() by removing assumptions on
the size of efi_memory_desc_t.
- various cleanups and fixes
The biggest risk is the get_memory_map() change, which changes the way
that both the arm64 and x86 EFI boot stub build the early memory map.
There are no known regressions with it at the moment, BYMMV"
* 'x86-efi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi: Don't look for chosen@0 node on DT platforms
firmware: efi: Remove unneeded guid unparse
efi/libstub: Call get_memory_map() to obtain map and desc sizes
efi: Small leak on error in runtime map code
efi: rtc-efi: Mark UIE as unsupported
arm64/efi: efistub: Apply __init annotation
efi: Expose underlying UEFI firmware platform size to userland
efi: Rename efi_guid_unparse to efi_guid_to_str
efi: Update the URLs for efibootmgr
fs: Make efivarfs a pseudo filesystem, built by default with EFI
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 cleanups from Ingo Molnar:
"Misc cleanups"
* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/rtc: Remove duplicate const specifier
x86, early_serial_console: Remove unnecessary check
x86, early_serial_console: Remove unused macro XMTRDY
x86, setup: Rename BOOT_ISDIGIT_H to BOOT_CTYPE_H
x86, CPU: Fix trivial printk formatting issues with dmesg
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 asm changes from Ingo Molnar:
"The main changes in this cycle were the x86/entry and sysret
enhancements from Andy Lutomirski, see merge commits 772a9aca125 and
b57c0b5175dd for details"
[ Exectutive summary: IST exceptions that interrupt user space will run
on the regular kernel stack instead of the IST stack. Which
simplifies things particularly on return to user space.
The sysret cleanup ends up simplifying the logic on when we can use
sysret vs when we have to use iret. - Linus ]
* 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86_64, entry: Remove the syscall exit audit and schedule optimizations
x86_64, entry: Use sysret to return to userspace when possible
x86, traps: Fix ist_enter from userspace
x86, vdso: teach 'make clean' remove vdso64 binaries
x86_64 entry: Fix RCX for ptraced syscalls
x86: entry_64.S: fold SAVE_ARGS_IRQ macro into its sole user
x86: ia32entry.S: fix wrong symbolic constant usage: R11->ARGOFFSET
x86: entry_64.S: delete unused code
x86, mce: Get rid of TIF_MCE_NOTIFY and associated mce tricks
x86, traps: Add ist_begin_non_atomic and ist_end_non_atomic
x86: Clean up current_stack_pointer
x86, traps: Track entry into and exit from IST context
x86, entry: Switch stacks on a paranoid entry from userspace
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 APIC updates from Ingo Molnar:
"Continued fallout of the conversion of the x86 IRQ code to the
hierarchical irqdomain framework: more cleanups, simplifications,
memory allocation behavior enhancements, mainly in the interrupt
remapping and APIC code"
* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (44 commits)
x86, init: Fix UP boot regression on x86_64
iommu/amd: Fix irq remapping detection logic
x86/acpi: Make acpi_[un]register_gsi_ioapic() depend on CONFIG_X86_LOCAL_APIC
x86: Consolidate boot cpu timer setup
x86/apic: Reuse apic_bsp_setup() for UP APIC setup
x86/smpboot: Sanitize uniprocessor init
x86/smpboot: Move apic init code to apic.c
init: Get rid of x86isms
x86/apic: Move apic_init_uniprocessor code
x86/smpboot: Cleanup ioapic handling
x86/apic: Sanitize ioapic handling
x86/ioapic: Add proper checks to setp/enable_IO_APIC()
x86/ioapic: Provide stub functions for IOAPIC%3Dn
x86/smpboot: Move smpboot inlines to code
x86/x2apic: Use state information for disable
x86/x2apic: Split enable and setup function
x86/x2apic: Disable x2apic from nox2apic setup
x86/x2apic: Add proper state tracking
x86/x2apic: Clarify remapping mode for x2apic enablement
x86/x2apic: Move code in conditional region
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
"Kernel side changes:
- AMD range breakpoints support:
Extend breakpoint tools and core to support address range through
perf event with initial backend support for AMD extended
breakpoints.
The syntax is:
perf record -e mem:addr/len:type
For example set write breakpoint from 0x1000 to 0x1200 (0x1000 + 512)
perf record -e mem:0x1000/512:w
- event throttling/rotating fixes
- various event group handling fixes, cleanups and general paranoia
code to be more robust against bugs in the future.
- kernel stack overhead fixes
User-visible tooling side changes:
- Show precise number of samples in at the end of a 'record' session,
if processing build ids, since we will then traverse the whole
perf.data file and see all the PERF_RECORD_SAMPLE records,
otherwise stop showing the previous off-base heuristicly counted
number of "samples" (Namhyung Kim).
- Support to read compressed module from build-id cache (Namhyung
Kim)
- Enable sampling loads and stores simultaneously in 'perf mem'
(Stephane Eranian)
- 'perf diff' output improvements (Namhyung Kim)
- Fix error reporting for evsel pgfault constructor (Arnaldo Carvalho
de Melo)
Tooling side infrastructure changes:
- Cache eh/debug frame offset for dwarf unwind (Namhyung Kim)
- Support parsing parameterized events (Cody P Schafer)
- Add support for IP address formats in libtraceevent (David Ahern)
Plus other misc fixes"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
perf: Decouple unthrottling and rotating
perf: Drop module reference on event init failure
perf: Use POLLIN instead of POLL_IN for perf poll data in flag
perf: Fix put_event() ctx lock
perf: Fix move_group() order
perf: Fix event->ctx locking
perf: Add a bit of paranoia
perf symbols: Convert lseek + read to pread
perf tools: Use perf_data_file__fd() consistently
perf symbols: Support to read compressed module from build-id cache
perf evsel: Set attr.task bit for a tracking event
perf header: Set header version correctly
perf record: Show precise number of samples
perf tools: Do not use __perf_session__process_events() directly
perf callchain: Cache eh/debug frame offset for dwarf unwind
perf tools: Provide stub for missing pthread_attr_setaffinity_np
perf evsel: Don't rely on malloc working for sz 0
tools lib traceevent: Add support for IP address formats
perf ui/tui: Show fatal error message only if exists
perf tests: Fix typo in sample-parsing.c
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RCU updates from Ingo Molnar:
"The main RCU changes in this cycle are:
- Documentation updates.
- Miscellaneous fixes.
- Preemptible-RCU fixes, including fixing an old bug in the
interaction of RCU priority boosting and CPU hotplug.
- SRCU updates.
- RCU CPU stall-warning updates.
- RCU torture-test updates"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (54 commits)
rcu: Initialize tiny RCU stall-warning timeouts at boot
rcu: Fix RCU CPU stall detection in tiny implementation
rcu: Add GP-kthread-starvation checks to CPU stall warnings
rcu: Make cond_resched_rcu_qs() apply to normal RCU flavors
rcu: Optionally run grace-period kthreads at real-time priority
ksoftirqd: Use new cond_resched_rcu_qs() function
ksoftirqd: Enable IRQs and call cond_resched() before poking RCU
rcutorture: Add more diagnostics in rcu_barrier() test failure case
torture: Flag console.log file to prevent holdovers from earlier runs
torture: Add "-enable-kvm -soundhw pcspk" to qemu command line
rcutorture: Handle different mpstat versions
rcutorture: Check from beginning to end of grace period
rcu: Remove redundant rcu_batches_completed() declaration
rcutorture: Drop rcu_torture_completed() and friends
rcu: Provide rcu_batches_completed_sched() for TINY_RCU
rcutorture: Use unsigned for Reader Batch computations
rcutorture: Make build-output parsing correctly flag RCU's warnings
rcu: Make _batches_completed() functions return unsigned long
rcutorture: Issue warnings on close calls due to Reader Batch blows
documentation: Fix smp typo in memory-barriers.txt
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi
Pull spi updates from Mark Brown:
"The major highlight this release is a refactoring of the core to allow
us to run synchronous transfers in the context of the caller when
there is no contention for the bus. This improves performance in the
very common case by eliminating context switches and reducing the
number of hardware setup and teardown operations we need to perform.
Other changes:
- New drivers for DLN-2 USB-SPI adapter and ST SPI controllers.
- A big round of cleanups, performance and feature improvements for
the xilinx driver from Ricardo Ribalda Delgado.
- A wide range of smaller cleanups, fixes and feature improvements
throughout the subsystem"
* tag 'spi-v3.20' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi: (68 commits)
spi: mxs: cleanup wait_for_completion return handling
spi: ti-qspi: cleanup wait_for_completion return handling
spi: spi-imx: cleanup wait_for_completion handling
spi: sh-msiof: cleanup wait_for_completion return handling
spi: match var type to return type of wait_for_completion
spi: spi-pxa2xx: only include mach/dma.h for legacy DMA
spi: atmel: cleanup wait_for_completion return handling
spi: fsl-dspi: Remove possible memory leak of 'chip'
spi: sh-msiof: Update calculation of frequency dividing
spi: spidev: Convert buf pointers for 32-bit compat SPI_IOC_MESSAGE(n)
spi/xilinx: Fix access invalid memory on xilinx_spi_tx
spi: Revert "spi/xilinx: Remove iowrite/ioread wrappers"
spi/xilinx: Check number of slaves range
spi/xilinx: Use polling mode on small transfers
spi/xilinx: Remove remaining_words driver data variable
spi/xilinx: Remove iowrite/ioread wrappers
spi/xilinx: Convert bits_per_word in bytes_per_word
spi/xilinx: Convert remainding_bytes in remaining words
spi/xilinx: Make spi_tx and spi_rx simmetric
spi/xilinx: Remove rx_fn and tx_fn pointer
...
|
|
git://git.rocketboards.org/linux-socfpga-next
Pull nios2 fix from Ley Foon Tan:
"This fixes incorrect behavior of some user programs"
* tag 'nios2-fixes-v3.19-final' of git://git.rocketboards.org/linux-socfpga-next:
nios2: fix unhandled signals
|
|
Follow other architectures for user fault handling.
Signed-off-by: Chung-Ling Tang <cltang@codesourcery.com>
Acked-by: Ley Foon Tan <lftan@altera.com>
|
|
'spi/topic/dln2' and 'spi/topic/dw' into spi-next
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer and x86 fix from Ingo Molnar:
"A CLOCK_TAI early expiry fix and an x86 microcode driver oops fix"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hrtimer: Fix incorrect tai offset calculation for non high-res timer systems
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86, microcode: Return error from driver init code when loader is disabled
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"Hopefully the final pull request for 3.19: this ended up with a
slightly higher volume than wished, but I put them all as they are
either stable or 3.19 regression fixes.
Most of commits are from ASoC, and have been stewed for a while in
linux-next. The only change in the common code is the regression
fixes for ASoC AC97 stuff wrt device registrations. The rest are
device-specific, mostly small fixes in various ASoC drivers and ak411x
on ice1724 boards"
* tag 'sound-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ASoC: Intel: fix sst firmware path for cht-bsw-rt5672
ARM: dts: Fix I2S1, I2S2 compatible for exynos4 SoCs
ASoC: sgtl5000: add delay before first I2C access
MAINTAINERS: ASoC: add maintainer for Intel BDW/HSW ASoC driver
ASoC: atmel_ssc_dai: fix the setting for DSP mode
ASoC: sgtl5000: Use shift mask when setting codec mode
ASoC: tlv320aic3x: Fix data delay configuration
ALSA: ak411x: Fix stall in work callback
ASoC: Intel: Used lock version to update shim registers
ASoC: wm8731: init mutex in i2c init path
ASoC: atmel_ssc_dai: fix start event for I2S mode
ASoC: rt5640: Add RT5642 ACPI ID for Intel Baytrail
ASoC: wm97xx: Reset AC'97 device before registering it
ASoC: Add support for allocating AC'97 device before registering it
|
|
Merge misc fixes from Andrew Morton:
"7 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
mm/debug_pagealloc: fix build failure on ppc and some other archs
nilfs2: fix deadlock of segment constructor over I_SYNC flag
MAINTAINERS: remove SUPERH website
memcg, shmem: fix shmem migration to use lrucare
mm: export "high_memory" symbol on !MMU
.mailmap: update Konstantin Khlebnikov's email address
mm: pagewalk: call pte_hole() for VM_PFNMAP during walk_page_range
|
|
Pull MIPS fixes from Ralf Baechle:
"The pending MIPS fixes for 3.19. All across the field and nothing
particularly severe or dramatic"
* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (23 commits)
IRQCHIP: mips-gic: Avoid rerouting timer IRQs for smp-cmp
MIPS: Fix syscall_get_nr for the syscall exit tracing.
MIPS: elf2ecoff: Ignore PT_MIPS_ABIFLAGS program headers.
MIPS: elf2ecoff: Rewrite main processing loop to switch.
MIPS: fork: Fix MSA/FPU/DSP context duplication race
MIPS: Fix C0_Pagegrain[IEC] support.
MIPS: traps: Fix inline asm ctc1 missing .set hardfloat
MIPS: mipsregs.h: Add write_32bit_cp1_register()
MIPS: Fix kernel lockup or crash after CPU offline/online
MIPS: OCTEON: fix kernel crash when offlining a CPU
MIPS: ARC: Fix build error.
MIPS: IRQ: Fix disable_irq on CPU IRQs
MIPS: smp-mt,smp-cmp: Enable all HW IRQs on secondary CPUs
MIPS: Fix restart of indirect syscalls
MIPS: ELF: fix loading o32 binaries on 64-bit kernels
MIPS: mips-cm: Fix sparse warnings
MIPS: Kconfig: Fix recursive dependency.
MIPS: Compat: Fix build error if CONFIG_MIPS32_COMPAT but no compat ABI.
MIPS: JZ4740: Fixup #include's (sparse)
MIPS: Wire up execveat(2).
...
|
|
Kim Phillips reported following build failure.
LD init/built-in.o
mm/built-in.o: In function `free_pages_prepare':
mm/page_alloc.c:770: undefined reference to `.kernel_map_pages'
mm/built-in.o: In function `prep_new_page':
mm/page_alloc.c:933: undefined reference to `.kernel_map_pages'
mm/built-in.o: In function `map_pages':
mm/compaction.c:61: undefined reference to `.kernel_map_pages'
make: *** [vmlinux] Error 1
Reason for this problem is that commit 031bc5743f15
("mm/debug-pagealloc: make debug-pagealloc boottime configurable")
forgot to remove the old declaration of kernel_map_pages() for some
architectures. This patch removes them to fix build failure.
Reported-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
|
|
I2S1, I2S2 on Exynos4 SoC series have limited functionality compared
to I2S0, "samsung,s3c6410-i2s" compatible should be used for them.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI fixes from Bjorn Helgaas:
"Enumeration
- Scan all device numbers on NEC as well as Stratus (Charlotte Richardson)
Resource management
- Handle read-only BARs on AMD CS553x devices (Myron Stowe)
Synopsys DesignWare
- Reject MSI-X IRQs (Lucas Stach)"
* tag 'pci-v3.19-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
PCI: Handle read-only BARs on AMD CS553x devices
PCI: Add NEC variants to Stratus ftServer PCIe DMI check
PCI: designware: Reject MSI-X IRQs
|
|
Pull ARM fixes from Russell King:
"A number of ARM fixes, the biggest is fixing a regression caused by
appended DT blobs exceeding 64K, causing the decompressor fixup code
to fail to patch the DT blob. Another important fix is for the ASID
allocator from Will Deacon which prevents some rare crashes seen on
some systems. Lastly, there's a build fix for v7M systems when printk
support is disabled.
The last two remaining fixes are more cosmetic - the IOMMU one
prevents an annoying harmless warning message, and we disable the
kernel strict memory permissions on non-MMU which can't support it
anyway"
* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
ARM: 8299/1: mm: ensure local active ASID is marked as allocated on rollover
ARM: 8298/1: ARM_KERNMEM_PERMS only works with MMU enabled
ARM: 8295/1: fix v7M build for !CONFIG_PRINTK
ARM: 8294/1: ATAG_DTB_COMPAT: remove the DT workspace's hardcoded 64KB size
ARM: 8288/1: dma-mapping: don't detach devices without an IOMMU during teardown
|
|
Register 2 is alredy overwritten by the return value when
syscall_trace_leave() is called.
Signed-off-by: Lars Persson <larper@axis.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9187/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
These are generated by very recent toolchains and result in an error
message when attenpting to convert a kernel from ELF to ECOFF.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
The if construct was getting hard to read and would be getting even more
complex with the next bug fix.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Commit e1a5848e3398 ("ARM: 7924/1: mm: don't bother with reserved ttbr0
when running with LPAE") removed the use of the reserved TTBR0 value
for LPAE systems, since the ASID is held in the TTBR and can be updated
atomicly with the pgd of the next mm.
Unfortunately, this patch forgot to update flush_context, which
deliberately avoids marking the local active ASID as allocated, since we
used to switch via ASID zero and didn't need to allocate the ASID of
the previous mm. The side-effect of this is that we can allocate the
same ASID to the next mm and, between flushing the local TLB and updating
TTBR0, we can perform speculative TLB fills for userspace nG mappings
using the page table of the previous mm.
The consequence of this is that the next mm can erroneously hit some
mappings of the previous mm. Note that this was made significantly
harder to hit by a391263cd84e ("ARM: 8203/1: mm: try to re-use old ASID
assignments following a rollover") but is still theoretically possible.
This patch fixes the problem by removing the code from flush_context
that forces the allocated ASID to zero for the local CPU. Many thanks
to the Broadcom guys for tracking this one down.
Fixes: e1a5848e3398 ("ARM: 7924/1: mm: don't bother with reserved ttbr0 when running with LPAE")
Cc: <stable@vger.kernel.org> # v3.14+
Reported-by: Raymond Ngun <rngun@broadcom.com>
Tested-by: Raymond Ngun <rngun@broadcom.com>
Reviewed-by: Gregory Fong <gregory.0xf0@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux into x86/asm
Pull "x86: Entry cleanups and a bugfix for 3.20" from Andy Lutomirski:
" This fixes a bug in the RCU code I added in ist_enter. It also includes
the sysret stuff discussed here:
http://lkml.kernel.org/g/cover.1421453410.git.luto%40amacapital.net "
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/luto/linux into x86/asm
Pull VDSO fix fro Andy Lutomirski:
"x86, vdso: One trivial last-minute VDSO build improvement
Andrey noticed that the VDSO build wasn't cleaning itself up. This
one-liner fixes it."
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
new changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
NEC OEMs the same platforms as Stratus does, which have multiple devices on
some PCIe buses under downstream ports.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=51331
Fixes: 1278998f8ff6 ("PCI: Work around Stratus ftServer broken PCIe hierarchy (fix DMI check)")
Signed-off-by: Charlotte Richardson <charlotte.richardson@stratus.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
CC: stable@vger.kernel.org # v3.5+
CC: Myron Stowe <myron.stowe@redhat.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC fixes from Olof Johansson:
"One more week's worth of fixes. Worth pointing out here are:
- A patch fixing detaching of iommu registrations when a device is
removed -- earlier the ops pointer wasn't managed properly
- Another set of Renesas boards get the same GIC setup fixup as
others have in previous -rcs
- Serial port aliases fixups for sunxi. We did the same to tegra but
we caught that in time before the merge window due to more machines
being affected. Here it took longer for anyone to notice.
- A couple more DT tweaks on sunxi
- A follow-up patch for the mvebu coherency disabling in last -rc
batch"
* tag 'armsoc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
arm: dma-mapping: Set DMA IOMMU ops in arm_iommu_attach_device()
ARM: shmobile: r8a7790: Instantiate GIC from C board code in legacy builds
ARM: shmobile: r8a73a4: Instantiate GIC from C board code in legacy builds
ARM: mvebu: don't set the PL310 in I/O coherency mode when I/O coherency is disabled
ARM: sunxi: dt: Fix aliases
ARM: dts: sun4i: Add simplefb node with de_fe0-de_be0-lcd0-hdmi pipeline
ARM: dts: sun6i: ippo-q8h-v5: Fix serial0 alias
ARM: dts: sunxi: Fix usb-phy support for sun4i/sun5i
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into fixes
Merge "Third Round of Renesas ARM Based SoC Fixes for v3.19" from Simon Horman:
* Instantiate GIC from C board code in legacy builds on r8a7790 and r8a73a4
* tag 'renesas-soc-fixes3-for-v3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
ARM: shmobile: r8a7790: Instantiate GIC from C board code in legacy builds
ARM: shmobile: r8a73a4: Instantiate GIC from C board code in legacy builds
Signed-off-by: Olof Johansson <olof@lixom.net>
|
|
We used to optimize rescheduling and audit on syscall exit. Now
that the full slow path is reasonably fast, remove these
optimizations. Syscall exit auditing is now handled exclusively by
syscall_trace_leave.
This adds something like 10ns to the previously optimized paths on
my computer, presumably due mostly to SAVE_REST / RESTORE_REST.
I think that we should eventually replace both the syscall and
non-paranoid interrupt exit slow paths with a pair of C functions
along the lines of the syscall entry hooks.
Link: http://lkml.kernel.org/r/22f2aa4a0361707a5cfb1de9d45260b39965dead.1421453410.git.luto@amacapital.net
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
|
|
The x86_64 entry code currently jumps through complex and
inconsistent hoops to try to minimize the impact of syscall exit
work. For a true fast-path syscall, almost nothing needs to be
done, so returning is just a check for exit work and sysret. For a
full slow-path return from a syscall, the C exit hook is invoked if
needed and we join the iret path.
Using iret to return to userspace is very slow, so the entry code
has accumulated various special cases to try to do certain forms of
exit work without invoking iret. This is error-prone, since it
duplicates assembly code paths, and it's dangerous, since sysret
can malfunction in interesting ways if used carelessly. It's
also inefficient, since a lot of useful cases aren't optimized
and therefore force an iret out of a combination of paranoia and
the fact that no one has bothered to write even more asm code
to avoid it.
I would argue that this approach is backwards. Rather than trying
to avoid the iret path, we should instead try to make the iret path
fast. Under a specific set of conditions, iret is unnecessary. In
particular, if RIP==RCX, RFLAGS==R11, RIP is canonical, RF is not
set, and both SS and CS are as expected, then
movq 32(%rsp),%rsp;sysret does the same thing as iret. This set of
conditions is nearly always satisfied on return from syscalls, and
it can even occasionally be satisfied on return from an irq.
Even with the careful checks for sysret applicability, this cuts
nearly 80ns off of the overhead from syscalls with unoptimized exit
work. This includes tracing and context tracking, and any return
that invokes KVM's user return notifier. For example, the cost of
getpid with CONFIG_CONTEXT_TRACKING_FORCE=y drops from ~360ns to
~280ns on my computer.
This may allow the removal and even eventual conversion to C
of a respectable amount of exit asm.
This may require further tweaking to give the full benefit on Xen.
It may be worthwhile to adjust signal delivery and exec to try hit
the sysret path.
This does not optimize returns to 32-bit userspace. Making the same
optimization for CS == __USER32_CS is conceptually straightforward,
but it will require some tedious code to handle the differences
between sysretl and sysexitl.
Link: http://lkml.kernel.org/r/71428f63e681e1b4aa1a781e3ef7c27f027d1103.1421453410.git.luto@amacapital.net
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
|
|
context_tracking_user_exit() has no effect if in_interrupt() returns true,
so ist_enter() didn't work. Fix it by calling exception_enter(), and thus
context_tracking_user_exit(), before incrementing the preempt count.
This also adds an assertion that will catch the problem reliably if
CONFIG_PROVE_RCU=y to help prevent the bug from being reintroduced.
Link: http://lkml.kernel.org/r/261ebee6aee55a4724746d0d7024697013c40a08.1422709102.git.luto@amacapital.net
Fixes: 959274753857 x86, traps: Track entry into and exit from IST context
Reported-and-tested-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
|
|
There is a race in the MIPS fork code which allows the child to get a
stale copy of parent MSA/FPU/DSP state that is active in hardware
registers when the fork() is called. This is because copy_thread() saves
the live register state into the child context only if the hardware is
currently in use, apparently on the assumption that the hardware state
cannot have been saved and disabled since the initial duplication of the
task_struct. However preemption is certainly possible during this
window.
An example sequence of events is as follows:
1) The parent userland process puts important data into saved floating
point registers ($f20-$f31), which are then dirty compared to the
process' stored context.
2) The parent process calls fork() which does a clone system call.
3) In the kernel, do_fork() -> copy_process() -> dup_task_struct() ->
arch_dup_task_struct() (which uses the weakly defined default
implementation). This duplicates the parent process' task context,
which includes a stale version of its FP context from when it was
last saved, probably some time before (1).
4) At some point before copy_process() calls copy_thread(), such as when
duplicating the memory map, the process is desceduled. Perhaps it is
preempted asynchronously, or perhaps it sleeps while blocked on a
mutex. The dirty FP state in the FP registers is saved to the parent
process' context and the FPU is disabled.
5) When the process is rescheduled again it continues copying state
until it gets to copy_thread(), which checks whether the FPU is in
use, so that it can copy that dirty state to the child process' task
context. Because of the deschedule however the FPU is not in use, so
the child process' context is left with stale FP context from the
last time the parent saved it (some time before (1)).
6) When the new child process is scheduled it reads the important data
from the saved floating point register, and ends up doing a NULL
pointer dereference as a result of the stale data.
This use of saved floating point registers across function calls can be
triggered fairly easily by explicitly using inline asm with a current
(MIPS R2) compiler, but is far more likely to happen unintentionally
with a MIPS R6 compiler where the FP registers are more likely to get
used as scratch registers for storing non-fp data.
It is easily fixed, in the same way that other architectures do it, by
overriding the implementation of arch_dup_task_struct() to sync the
dirty hardware state to the parent process' task context *prior* to
duplicating it, rather than copying straight to the child process' task
context in copy_thread(). Note, the FPU hardware is not disabled so the
parent process may continue executing with the live register context,
but now the child process is guaranteed to have an identical copy of it
at that point.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Reported-by: Matthew Fortune <matthew.fortune@imgtec.com>
Tested-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9075/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
The following commits:
5890f70f15c52d (MIPS: Use dedicated exception handler if CPU supports RI/XI exceptions)
6575b1d4173eae (MIPS: kernel: cpu-probe: Detect unique RI/XI exceptions)
break the kernel for *all* existing MIPS CPUs that implement the
CP0_PageGrain[IEC] bit. They cause the TLB exception handlers to be
generated without the legacy execute-inhibit handling, but never set
the CP0_PageGrain[IEC] bit to activate the use of dedicated exception
vectors for execute-inhibit exceptions. The result is that upon
detection of an execute-inhibit violation, we loop forever in the TLB
exception handlers instead of sending SIGSEGV to the task.
If we are generating TLB exception handlers expecting separate
vectors, we must also enable the CP0_PageGrain[IEC] feature.
The bug was introduced in kernel version 3.17.
Signed-off-by: David Daney <david.daney@cavium.com>
Cc: <stable@vger.kernel.org>
Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/8880/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
"Mostly tooling fixes, but also an event groups fix, two PMU driver
fixes and a CPU model variant addition"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Tighten (and fix) the grouping condition
perf/x86/intel: Add model number for Airmont
perf/rapl: Fix crash in rapl_scale()
perf/x86/intel/uncore: Move uncore_box_init() out of driver initialization
perf probe: Fix probing kretprobes
perf symbols: Introduce 'for' method to iterate over the symbols with a given name
perf probe: Do not rely on map__load() filter to find symbols
perf symbols: Introduce method to iterate symbols ordered by name
perf symbols: Return the first entry with a given name in find_by_name method
perf annotate: Fix memory leaks in LOCK handling
perf annotate: Handle ins parsing failures
perf scripting perl: Force to use stdbool
perf evlist: Remove extraneous 'was' on error message
|
|
Commit 842dfc11ea9a ("MIPS: Fix build with binutils 2.24.51+") in v3.18
enabled -msoft-float and sprinkled ".set hardfloat" where necessary to
use FP instructions. However it missed enable_restore_fp_context() which
since v3.17 does a ctc1 with inline assembly, causing the following
assembler errors on Mentor's 2014.05 toolchain:
{standard input}: Assembler messages:
{standard input}:2913: Error: opcode not supported on this processor: mips32r2 (mips32r2) `ctc1 $2,$31'
scripts/Makefile.build:257: recipe for target 'arch/mips/kernel/traps.o' failed
Fix that to use the new write_32bit_cp1_register() macro so that ".set
hardfloat" is automatically added when -msoft-float is in use.
Fixes 842dfc11ea9a ("MIPS: Fix build with binutils 2.24.51+")
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.18+, depends on "MIPS: mipsregs.h: Add write_32bit_cp1_register()"
Patchwork: https://patchwork.linux-mips.org/patch/9173/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
Add a write_32bit_cp1_register() macro to compliment the
read_32bit_cp1_register() macro. This is to abstract whether .set
hardfloat needs to be used based on GAS_HAS_SET_HARDFLOAT.
The implementation of _read_32bit_cp1_register() .sets mips1 due to
failure of gas v2.19 to assemble cfc1 for Octeon (see commit
25c300030016 ("MIPS: Override assembler target architecture for
octeon.")). I haven't copied this over to _write_32bit_cp1_register() as
I'm uncertain whether it applies to ctc1 too, or whether anybody cares
about that version of binutils any longer.
Signed-off-by: James Hogan <james.hogan@imgtec.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/9172/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
Pull KVM fixes from Paolo Bonzini:
"The ARM changes are largish, but not too scary. And a simple fix for
x86 (bug introduced in 3.19)"
(Paolo sayus these are the "Final" fixes. We'll see).
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: check LAPIC presence when building apic_map
arm/arm64: KVM: Use kernel mapping to perform invalidation on page fault
arm/arm64: KVM: Invalidate data cache on unmap
arm/arm64: KVM: Use set/way op trapping to track the state of the caches
|
|
Fix misspelled define.
Fixes: 33692f27597f ("vm: add VM_FAULT_SIGSEGV handling support")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
We forgot to re-check LAPIC after splitting the loop in commit
173beedc1601 (KVM: x86: Software disabled APIC should still deliver
NMIs, 2014-11-02).
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Fixes: 173beedc1601f51dae9d579aa7a414c5aa8f700b
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master
Second round of fixes for KVM/ARM for 3.19.
Fixes memory corruption issues on APM platforms and swapping issues on
DMA-coherent systems.
|
|
As printk() invocation can cause e.g. a TLB miss, printk() cannot be
called before the exception handlers have been properly initialized.
This can happen e.g. when netconsole has been loaded as a kernel module
and the TLB table has been cleared when a CPU was offline.
Call cpu_report() in start_secondary() only after the exception handlers
have been initialized to fix this.
Without the patch the kernel will randomly either lockup or crash
after a CPU is onlined and the console driver is a module.
Signed-off-by: Hemmo Nieminen <hemmo.nieminen@iki.fi>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: stable@vger.kernel.org
Cc: David Daney <david.daney@cavium.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8953/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
octeon_cpu_disable() will unconditionally enable interrupts when called.
We can assume that the routine is always called with interrupts disabled,
so just delete the incorrect local_irq_disable/enable().
The patch fixes the following crash when offlining a CPU:
[ 93.818785] ------------[ cut here ]------------
[ 93.823421] WARNING: CPU: 1 PID: 10 at kernel/smp.c:231 flush_smp_call_function_queue+0x1c4/0x1d0()
[ 93.836215] Modules linked in:
[ 93.839287] CPU: 1 PID: 10 Comm: migration/1 Not tainted 3.19.0-rc4-octeon-los_b5f0 #1
[ 93.847212] Stack : 0000000000000001 ffffffff81b2cf90 0000000000000004 ffffffff81630000
0000000000000000 0000000000000000 0000000000000000 000000000000004a
0000000000000006 ffffffff8117e550 0000000000000000 0000000000000000
ffffffff81b30000 ffffffff81b26808 8000000032c77748 ffffffff81627e07
ffffffff81595ec8 ffffffff81b26808 000000000000000a 0000000000000001
0000000000000001 0000000000000003 0000000010008ce1 ffffffff815030c8
8000000032cbbb38 ffffffff8113d42c 0000000010008ce1 ffffffff8117f36c
8000000032c77300 8000000032cbba50 0000000000000001 ffffffff81503984
0000000000000000 0000000000000000 0000000000000000 0000000000000000
0000000000000000 ffffffff81121668 0000000000000000 0000000000000000
...
[ 93.912819] Call Trace:
[ 93.915273] [<ffffffff81121668>] show_stack+0x68/0x80
[ 93.920335] [<ffffffff81503984>] dump_stack+0x6c/0x90
[ 93.925395] [<ffffffff8113d58c>] warn_slowpath_common+0x94/0xd8
[ 93.931324] [<ffffffff811a402c>] flush_smp_call_function_queue+0x1c4/0x1d0
[ 93.938208] [<ffffffff811a4128>] hotplug_cfd+0xf0/0x108
[ 93.943444] [<ffffffff8115bacc>] notifier_call_chain+0x5c/0xb8
[ 93.949286] [<ffffffff8113d704>] cpu_notify+0x24/0x60
[ 93.954348] [<ffffffff81501738>] take_cpu_down+0x38/0x58
[ 93.959670] [<ffffffff811b343c>] multi_cpu_stop+0x154/0x180
[ 93.965250] [<ffffffff811b3768>] cpu_stopper_thread+0xd8/0x160
[ 93.971093] [<ffffffff8115ea4c>] smpboot_thread_fn+0x1ec/0x1f8
[ 93.976936] [<ffffffff8115ab04>] kthread+0xd4/0xf0
[ 93.981735] [<ffffffff8111c4f0>] ret_from_kernel_thread+0x14/0x1c
[ 93.987835]
[ 93.989326] ---[ end trace c9e3815ee655bda9 ]---
[ 93.993951] Kernel bug detected[#1]:
[ 93.997533] CPU: 1 PID: 10 Comm: migration/1 Tainted: G W 3.19.0-rc4-octeon-los_b5f0 #1
[ 94.006591] task: 8000000032c77300 ti: 8000000032cb8000 task.ti: 8000000032cb8000
[ 94.014081] $ 0 : 0000000000000000 0000000010000ce1 0000000000000001 ffffffff81620000
[ 94.022146] $ 4 : 8000000002c72ac0 0000000000000000 00000000000001a7 ffffffff813b06f0
[ 94.030210] $ 8 : ffffffff813b20d8 0000000000000000 0000000000000000 ffffffff81630000
[ 94.038275] $12 : 0000000000000087 0000000000000000 0000000000000086 0000000000000000
[ 94.046339] $16 : ffffffff81623168 0000000000000001 0000000000000000 0000000000000008
[ 94.054405] $20 : 0000000000000001 0000000000000001 0000000000000001 0000000000000003
[ 94.062470] $24 : 0000000000000038 ffffffff813b7f10
[ 94.070536] $28 : 8000000032cb8000 8000000032cbbc20 0000000010008ce1 ffffffff811bcaf4
[ 94.078601] Hi : 0000000000f188e8
[ 94.082179] Lo : d4fdf3b646c09d55
[ 94.085760] epc : ffffffff811bc9d0 irq_work_run_list+0x8/0xf8
[ 94.091686] Tainted: G W
[ 94.095613] ra : ffffffff811bcaf4 irq_work_run+0x34/0x60
[ 94.101192] Status: 10000ce3 KX SX UX KERNEL EXL IE
[ 94.106235] Cause : 40808034
[ 94.109119] PrId : 000d9301 (Cavium Octeon II)
[ 94.113653] Modules linked in:
[ 94.116721] Process migration/1 (pid: 10, threadinfo=8000000032cb8000, task=8000000032c77300, tls=0000000000000000)
[ 94.127168] Stack : 8000000002c74c80 ffffffff811a4128 0000000000000001 ffffffff81635720
fffffffffffffff2 ffffffff8115bacc 80000000320fbce0 80000000320fbca4
80000000320fbc80 0000000000000002 0000000000000004 ffffffff8113d704
80000000320fbce0 ffffffff81501738 0000000000000003 ffffffff811b343c
8000000002c72aa0 8000000002c72aa8 ffffffff8159cae8 ffffffff8159caa0
ffffffff81650000 80000000320fbbf0 80000000320fbc80 ffffffff811b32e8
0000000000000000 ffffffff811b3768 ffffffff81622b80 ffffffff815148a8
8000000032c77300 8000000002c73e80 ffffffff815148a8 8000000032c77300
ffffffff81622b80 ffffffff815148a8 8000000032c77300 ffffffff81503f48
ffffffff8115ea0c ffffffff81620000 0000000000000000 ffffffff81174d64
...
[ 94.192771] Call Trace:
[ 94.195222] [<ffffffff811bc9d0>] irq_work_run_list+0x8/0xf8
[ 94.200802] [<ffffffff811bcaf4>] irq_work_run+0x34/0x60
[ 94.206036] [<ffffffff811a4128>] hotplug_cfd+0xf0/0x108
[ 94.211269] [<ffffffff8115bacc>] notifier_call_chain+0x5c/0xb8
[ 94.217111] [<ffffffff8113d704>] cpu_notify+0x24/0x60
[ 94.222171] [<ffffffff81501738>] take_cpu_down+0x38/0x58
[ 94.227491] [<ffffffff811b343c>] multi_cpu_stop+0x154/0x180
[ 94.233072] [<ffffffff811b3768>] cpu_stopper_thread+0xd8/0x160
[ 94.238914] [<ffffffff8115ea4c>] smpboot_thread_fn+0x1ec/0x1f8
[ 94.244757] [<ffffffff8115ab04>] kthread+0xd4/0xf0
[ 94.249555] [<ffffffff8111c4f0>] ret_from_kernel_thread+0x14/0x1c
[ 94.255654]
[ 94.257146]
Code: a2423c40 40026000 30420001 <00020336> dc820000 10400037 00000000 0000010f 0000010f
[ 94.267183] ---[ end trace c9e3815ee655bdaa ]---
[ 94.271804] Fatal exception: panic in 5 seconds
Reported-by: Hemmo Nieminen <hemmo.nieminen@iki.fi>
Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Acked-by: David Daney <david.daney@cavium.com>
Cc: stable@vger.kernel.org # v3.18+
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/8952/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
|
|
When handling a fault in stage-2, we need to resync I$ and D$, just
to be sure we don't leave any old cache line behind.
That's very good, except that we do so using the *user* address.
Under heavy load (swapping like crazy), we may end up in a situation
where the page gets mapped in stage-2 while being unmapped from
userspace by another CPU.
At that point, the DC/IC instructions can generate a fault, which
we handle with kvm->mmu_lock held. The box quickly deadlocks, user
is unhappy.
Instead, perform this invalidation through the kernel mapping,
which is guaranteed to be present. The box is much happier, and so
am I.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
|
|
Let's assume a guest has created an uncached mapping, and written
to that page. Let's also assume that the host uses a cache-coherent
IO subsystem. Let's finally assume that the host is under memory
pressure and starts to swap things out.
Before this "uncached" page is evicted, we need to make sure
we invalidate potential speculated, clean cache lines that are
sitting there, or the IO subsystem is going to swap out the
cached view, loosing the data that has been written directly
into memory.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
|
|
Trying to emulate the behaviour of set/way cache ops is fairly
pointless, as there are too many ways we can end-up missing stuff.
Also, there is some system caches out there that simply ignore
set/way operations.
So instead of trying to implement them, let's convert it to VA ops,
and use them as a way to re-enable the trapping of VM ops. That way,
we can detect the point when the MMU/caches are turned off, and do
a full VM flush (which is what the guest was trying to do anyway).
This allows a 32bit zImage to boot on the APM thingy, and will
probably help bootloaders in general.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
|
|
Commit 4bb25789ed28228a ("arm: dma-mapping: plumb our iommu mapping ops
into arch_setup_dma_ops") moved the setting of the DMA operations from
arm_iommu_attach_device() to arch_setup_dma_ops() where the DMA
operations to be used are selected based on whether the device is
connected to an IOMMU. However, the IOMMU detection scheme requires the
IOMMU driver to be ported to the new IOMMU of_xlate API. As no driver
has been ported yet, this effectively breaks all IOMMU ARM users that
depend on the IOMMU being handled transparently by the DMA mapping API.
Fix this by restoring the setting of DMA IOMMU ops in
arm_iommu_attach_device() and splitting the rest of the function into a
new internal __arm_iommu_attach_device() function, called by
arch_setup_dma_ops().
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Olof Johansson <olof@lixom.net>
|
|
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 fee7e49d4514 ("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>
|
