Expose FPMR in the signal context on systems where it is supported. The
kernel validates the exact size of the FPSIMD registers so we can't readily
add it to fpsimd_context without disruption.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20240306-arm64-2023-dpisa-v5-4-c568edc8ed7f@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
The arm64 documentation has moved under Documentation/arch/; fix up
references in the arm64 subtree to match.
Cc: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
* arm64/for-next/perf:
perf: arm_spe: Print the version of SPE detected
perf: arm_spe: Add support for SPEv1.2 inverted event filtering
perf: Add perf_event_attr::config3
drivers/perf: fsl_imx8_ddr_perf: Remove set-but-not-used variable
perf: arm_spe: Support new SPEv1.2/v8.7 'not taken' event
perf: arm_spe: Use new PMSIDR_EL1 register enums
perf: arm_spe: Drop BIT() and use FIELD_GET/PREP accessors
arm64/sysreg: Convert SPE registers to automatic generation
arm64: Drop SYS_ from SPE register defines
perf: arm_spe: Use feature numbering for PMSEVFR_EL1 defines
perf/marvell: Add ACPI support to TAD uncore driver
perf/marvell: Add ACPI support to DDR uncore driver
perf/arm-cmn: Reset DTM_PMU_CONFIG at probe
drivers/perf: hisi: Extract initialization of "cpa_pmu->pmu"
drivers/perf: hisi: Simplify the parameters of hisi_pmu_init()
drivers/perf: hisi: Advertise the PERF_PMU_CAP_NO_EXCLUDE capability
* for-next/sysreg:
: arm64 sysreg and cpufeature fixes/updates
KVM: arm64: Use symbolic definition for ISR_EL1.A
arm64/sysreg: Add definition of ISR_EL1
arm64/sysreg: Add definition for ICC_NMIAR1_EL1
arm64/cpufeature: Remove 4 bit assumption in ARM64_FEATURE_MASK()
arm64/sysreg: Fix errors in 32 bit enumeration values
arm64/cpufeature: Fix field sign for DIT hwcap detection
* for-next/sme:
: SME-related updates
arm64/sme: Optimise SME exit on syscall entry
arm64/sme: Don't use streaming mode to probe the maximum SME VL
arm64/ptrace: Use system_supports_tpidr2() to check for TPIDR2 support
* for-next/kselftest: (23 commits)
: arm64 kselftest fixes and improvements
kselftest/arm64: Don't require FA64 for streaming SVE+ZA tests
kselftest/arm64: Copy whole EXTRA context
kselftest/arm64: Fix enumeration of systems without 128 bit SME for SSVE+ZA
kselftest/arm64: Fix enumeration of systems without 128 bit SME
kselftest/arm64: Don't require FA64 for streaming SVE tests
kselftest/arm64: Limit the maximum VL we try to set via ptrace
kselftest/arm64: Correct buffer size for SME ZA storage
kselftest/arm64: Remove the local NUM_VL definition
kselftest/arm64: Verify simultaneous SSVE and ZA context generation
kselftest/arm64: Verify that SSVE signal context has SVE_SIG_FLAG_SM set
kselftest/arm64: Remove spurious comment from MTE test Makefile
kselftest/arm64: Support build of MTE tests with clang
kselftest/arm64: Initialise current at build time in signal tests
kselftest/arm64: Don't pass headers to the compiler as source
kselftest/arm64: Remove redundant _start labels from FP tests
kselftest/arm64: Fix .pushsection for strings in FP tests
kselftest/arm64: Run BTI selftests on systems without BTI
kselftest/arm64: Fix test numbering when skipping tests
kselftest/arm64: Skip non-power of 2 SVE vector lengths in fp-stress
kselftest/arm64: Only enumerate power of two VLs in syscall-abi
...
* for-next/misc:
: Miscellaneous arm64 updates
arm64/mm: Intercept pfn changes in set_pte_at()
Documentation: arm64: correct spelling
arm64: traps: attempt to dump all instructions
arm64: Apply dynamic shadow call stack patching in two passes
arm64: el2_setup.h: fix spelling typo in comments
arm64: Kconfig: fix spelling
arm64: cpufeature: Use kstrtobool() instead of strtobool()
arm64: Avoid repeated AA64MMFR1_EL1 register read on pagefault path
arm64: make ARCH_FORCE_MAX_ORDER selectable
* for-next/sme2: (23 commits)
: Support for arm64 SME 2 and 2.1
arm64/sme: Fix __finalise_el2 SMEver check
kselftest/arm64: Remove redundant _start labels from zt-test
kselftest/arm64: Add coverage of SME 2 and 2.1 hwcaps
kselftest/arm64: Add coverage of the ZT ptrace regset
kselftest/arm64: Add SME2 coverage to syscall-abi
kselftest/arm64: Add test coverage for ZT register signal frames
kselftest/arm64: Teach the generic signal context validation about ZT
kselftest/arm64: Enumerate SME2 in the signal test utility code
kselftest/arm64: Cover ZT in the FP stress test
kselftest/arm64: Add a stress test program for ZT0
arm64/sme: Add hwcaps for SME 2 and 2.1 features
arm64/sme: Implement ZT0 ptrace support
arm64/sme: Implement signal handling for ZT
arm64/sme: Implement context switching for ZT0
arm64/sme: Provide storage for ZT0
arm64/sme: Add basic enumeration for SME2
arm64/sme: Enable host kernel to access ZT0
arm64/sme: Manually encode ZT0 load and store instructions
arm64/esr: Document ISS for ZT0 being disabled
arm64/sme: Document SME 2 and SME 2.1 ABI
...
* for-next/tpidr2:
: Include TPIDR2 in the signal context
kselftest/arm64: Add test case for TPIDR2 signal frame records
kselftest/arm64: Add TPIDR2 to the set of known signal context records
arm64/signal: Include TPIDR2 in the signal context
arm64/sme: Document ABI for TPIDR2 signal information
* for-next/scs:
: arm64: harden shadow call stack pointer handling
arm64: Stash shadow stack pointer in the task struct on interrupt
arm64: Always load shadow stack pointer directly from the task struct
* for-next/compat-hwcap:
: arm64: Expose compat ARMv8 AArch32 features (HWCAPs)
arm64: Add compat hwcap SSBS
arm64: Add compat hwcap SB
arm64: Add compat hwcap I8MM
arm64: Add compat hwcap ASIMDBF16
arm64: Add compat hwcap ASIMDFHM
arm64: Add compat hwcap ASIMDDP
arm64: Add compat hwcap FPHP and ASIMDHP
* for-next/ftrace:
: Add arm64 support for DYNAMICE_FTRACE_WITH_CALL_OPS
arm64: avoid executing padding bytes during kexec / hibernation
arm64: Implement HAVE_DYNAMIC_FTRACE_WITH_CALL_OPS
arm64: ftrace: Update stale comment
arm64: patching: Add aarch64_insn_write_literal_u64()
arm64: insn: Add helpers for BTI
arm64: Extend support for CONFIG_FUNCTION_ALIGNMENT
ACPI: Don't build ACPICA with '-Os'
Compiler attributes: GCC cold function alignment workarounds
ftrace: Add DYNAMIC_FTRACE_WITH_CALL_OPS
* for-next/efi-boot-mmu-on:
: Permit arm64 EFI boot with MMU and caches on
arm64: kprobes: Drop ID map text from kprobes blacklist
arm64: head: Switch endianness before populating the ID map
efi: arm64: enter with MMU and caches enabled
arm64: head: Clean the ID map and the HYP text to the PoC if needed
arm64: head: avoid cache invalidation when entering with the MMU on
arm64: head: record the MMU state at primary entry
arm64: kernel: move identity map out of .text mapping
arm64: head: Move all finalise_el2 calls to after __enable_mmu
* for-next/ptrauth:
: arm64 pointer authentication cleanup
arm64: pauth: don't sign leaf functions
arm64: unify asm-arch manipulation
* for-next/pseudo-nmi:
: Pseudo-NMI code generation optimisations
arm64: irqflags: use alternative branches for pseudo-NMI logic
arm64: add ARM64_HAS_GIC_PRIO_RELAXED_SYNC cpucap
arm64: make ARM64_HAS_GIC_PRIO_MASKING depend on ARM64_HAS_GIC_CPUIF_SYSREGS
arm64: rename ARM64_HAS_IRQ_PRIO_MASKING to ARM64_HAS_GIC_PRIO_MASKING
arm64: rename ARM64_HAS_SYSREG_GIC_CPUIF to ARM64_HAS_GIC_CPUIF_SYSREGS
Add a new signal frame record for TPIDR2 using the same format as we
already use for ESR with different magic, a header with the value from the
register appended as the only data. If SME is supported then this record is
always included.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Link: https://lore.kernel.org/r/20221208-arm64-tpidr2-sig-v3-2-c77c6c8775f4@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Add a new signal context type for ZT which is present in the signal frame
when ZA is enabled and ZT is supported by the system. In order to account
for the possible addition of further ZT registers in the future we make the
number of registers variable in the ABI, though currently the only possible
number is 1. We could just use a bare list head for the context since the
number of registers can be inferred from the size of the context but for
usability and future extensibility we define a header with the number of
registers and some reserved fields in it.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221208-arm64-sme2-v4-11-f2fa0aef982f@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Szabolcs Nagy has pointed out that most of our signal frame magic numbers
are chosen to be meaningful ASCII when dumped to aid manual parsing. This
seems sensible since it might help someone parsing things out, let's
document it so people implementing new signal contexts are aware of it and
are more likely to follow it.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20221031192450.826159-1-broonie@kernel.org
[will: Fixed typo and tweaked wording]
Signed-off-by: Will Deacon <will@kernel.org>
Implement support for ZA in signal handling in a very similar way to how
we implement support for SVE registers, using a signal context structure
with optional register state after it. Where present this register state
stores the ZA matrix as a series of horizontal vectors numbered from 0 to
VL/8 in the endinanness independent format used for vectors.
As with SVE we do not allow changes in the vector length during signal
return but we do allow ZA to be enabled or disabled.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-20-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
When in streaming mode we have the same set of SVE registers as we do in
regular SVE mode with the exception of FFR and the use of the SME vector
length. Provide signal handling for these registers by taking one of the
reserved words in the SVE signal context as a flags field and defining a
flag which is set for streaming mode. When the flag is set the vector
length is set to the streaming mode vector length and we save and
restore streaming mode data. We support entering or leaving streaming
mode based on the value of the flag but do not support changing the
vector length, this is not currently supported SVE signal handling.
We could instead allocate a separate record in the signal frame for the
streaming mode SVE context but this inflates the size of the maximal signal
frame required and adds complication when validating signal frames from
userspace, especially given the current structure of the code.
Any implementation of support for streaming mode vectors in signals will
have some potential for causing issues for applications that attempt to
handle SVE vectors in signals, use streaming mode but do not understand
streaming mode in their signal handling code, it is hard to identify a
case that is clearly better than any other - they all have cases where
they could cause unexpected register corruption or faults.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-19-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
- A fair pile of RST conversions, many from Mauro. These create more
than the usual number of simple but annoying merge conflicts with other
trees, unfortunately. He has a lot more of these waiting on the wings
that, I think, will go to you directly later on.
- A new document on how to use merges and rebases in kernel repos, and one
on Spectre vulnerabilities.
- Various improvements to the build system, including automatic markup of
function() references because some people, for reasons I will never
understand, were of the opinion that :c:func:``function()`` is
unattractive and not fun to type.
- We now recommend using sphinx 1.7, but still support back to 1.4.
- Lots of smaller improvements, warning fixes, typo fixes, etc.
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Merge tag 'docs-5.3' of git://git.lwn.net/linux
Pull Documentation updates from Jonathan Corbet:
"It's been a relatively busy cycle for docs:
- A fair pile of RST conversions, many from Mauro. These create more
than the usual number of simple but annoying merge conflicts with
other trees, unfortunately. He has a lot more of these waiting on
the wings that, I think, will go to you directly later on.
- A new document on how to use merges and rebases in kernel repos,
and one on Spectre vulnerabilities.
- Various improvements to the build system, including automatic
markup of function() references because some people, for reasons I
will never understand, were of the opinion that
:c:func:``function()`` is unattractive and not fun to type.
- We now recommend using sphinx 1.7, but still support back to 1.4.
- Lots of smaller improvements, warning fixes, typo fixes, etc"
* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
docs: automarkup.py: ignore exceptions when seeking for xrefs
docs: Move binderfs to admin-guide
Disable Sphinx SmartyPants in HTML output
doc: RCU callback locks need only _bh, not necessarily _irq
docs: format kernel-parameters -- as code
Doc : doc-guide : Fix a typo
platform: x86: get rid of a non-existent document
Add the RCU docs to the core-api manual
Documentation: RCU: Add TOC tree hooks
Documentation: RCU: Rename txt files to rst
Documentation: RCU: Convert RCU UP systems to reST
Documentation: RCU: Convert RCU linked list to reST
Documentation: RCU: Convert RCU basic concepts to reST
docs: filesystems: Remove uneeded .rst extension on toctables
scripts/sphinx-pre-install: fix out-of-tree build
docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
Documentation: PGP: update for newer HW devices
Documentation: Add section about CPU vulnerabilities for Spectre
Documentation: platform: Delete x86-laptop-drivers.txt
docs: Note that :c:func: should no longer be used
...
The documentation is in a format that is very close to ReST format.
The conversion is actually:
- add blank lines in order to identify paragraphs;
- fixing tables markups;
- adding some lists markups;
- marking literal blocks;
- adjust some title markups.
At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
The in-memory representation of SVE and FPSIMD registers is
different: the FPSIMD V-registers are stored as single 128-bit
host-endian values, whereas SVE registers are stored in an
endianness-invariant byte order.
This means that the two representations differ when running on a
big-endian host. But we blindly copy data from one representation
to another when converting between the two, resulting in the
register contents being unintentionally byteswapped in certain
situations. Currently this can be triggered by the first SVE
instruction after a syscall, for example (though the potential
trigger points may vary in future).
So, fix the conversion functions fpsimd_to_sve(), sve_to_fpsimd()
and sve_sync_from_fpsimd_zeropad() to swab where appropriate.
There is no common swahl128() or swab128() that we could use here.
Maybe it would be worth making this generic, but for now add a
simple local hack.
Since the byte order differences are exposed in ABI, also clarify
the documentation.
Cc: Alex Bennée <alex.bennee@linaro.org>
Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Alan Hayward <alan.hayward@arm.com>
Cc: Julien Grall <julien.grall@arm.com>
Fixes: bc0ee47603 ("arm64/sve: Core task context handling")
Fixes: 8cd969d28f ("arm64/sve: Signal handling support")
Fixes: 43d4da2c45 ("arm64/sve: ptrace and ELF coredump support")
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
[will: Fix typos in comments and docs spotted by Julien]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Currently, <uapi/asm/sigcontext.h> provides common definitions for
describing SVE context structures that are also used by the ptrace
definitions in <uapi/asm/ptrace.h>.
For this reason, a #include of <asm/sigcontext.h> was added in
ptrace.h, but it this turns out that this can interact badly with
userspace code that tries to include ptrace.h on top of the libc
headers (which may provide their own shadow definitions for
sigcontext.h).
To make the headers easier for userspace to consume, this patch
bounces the common definitions into an __SVE_* namespace and moves
them to a backend header <uapi/asm/sve_context.h> that can be
included by the other headers as appropriate. This should allow
ptrace.h to be used alongside libc's sigcontext.h (if any) without
ill effects.
This should make the situation unambiguous: <asm/sigcontext.h> is
the header to include for the sigframe-specific definitions, while
<asm/ptrace.h> is the header to include for ptrace-specific
definitions.
To avoid conflicting with existing usage, <asm/sigcontext.h>
remains the canonical way to get the common definitions for
SVE_VQ_MIN, sve_vq_from_vl() etc., both in userspace and in the
kernel: relying on these being defined as a side effect of
including just <asm/ptrace.h> was never intended to be safe.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Plenty of acronym soup here:
- Initial support for the Scalable Vector Extension (SVE)
- Improved handling for SError interrupts (required to handle RAS events)
- Enable GCC support for 128-bit integer types
- Remove kernel text addresses from backtraces and register dumps
- Use of WFE to implement long delay()s
- ACPI IORT updates from Lorenzo Pieralisi
- Perf PMU driver for the Statistical Profiling Extension (SPE)
- Perf PMU driver for Hisilicon's system PMUs
- Misc cleanups and non-critical fixes
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
"The big highlight is support for the Scalable Vector Extension (SVE)
which required extensive ABI work to ensure we don't break existing
applications by blowing away their signal stack with the rather large
new vector context (<= 2 kbit per vector register). There's further
work to be done optimising things like exception return, but the ABI
is solid now.
Much of the line count comes from some new PMU drivers we have, but
they're pretty self-contained and I suspect we'll have more of them in
future.
Plenty of acronym soup here:
- initial support for the Scalable Vector Extension (SVE)
- improved handling for SError interrupts (required to handle RAS
events)
- enable GCC support for 128-bit integer types
- remove kernel text addresses from backtraces and register dumps
- use of WFE to implement long delay()s
- ACPI IORT updates from Lorenzo Pieralisi
- perf PMU driver for the Statistical Profiling Extension (SPE)
- perf PMU driver for Hisilicon's system PMUs
- misc cleanups and non-critical fixes"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (97 commits)
arm64: Make ARMV8_DEPRECATED depend on SYSCTL
arm64: Implement __lshrti3 library function
arm64: support __int128 on gcc 5+
arm64/sve: Add documentation
arm64/sve: Detect SVE and activate runtime support
arm64/sve: KVM: Hide SVE from CPU features exposed to guests
arm64/sve: KVM: Treat guest SVE use as undefined instruction execution
arm64/sve: KVM: Prevent guests from using SVE
arm64/sve: Add sysctl to set the default vector length for new processes
arm64/sve: Add prctl controls for userspace vector length management
arm64/sve: ptrace and ELF coredump support
arm64/sve: Preserve SVE registers around EFI runtime service calls
arm64/sve: Preserve SVE registers around kernel-mode NEON use
arm64/sve: Probe SVE capabilities and usable vector lengths
arm64: cpufeature: Move sys_caps_initialised declarations
arm64/sve: Backend logic for setting the vector length
arm64/sve: Signal handling support
arm64/sve: Support vector length resetting for new processes
arm64/sve: Core task context handling
arm64/sve: Low-level CPU setup
...
This patch adds basic documentation of the user/kernel interface
provided by the for SVE.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alan Hayward <alan.hayward@arm.com>
Cc: Alex Bennée <alex.bennee@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: linux-api@vger.kernel.org
Signed-off-by: Will Deacon <will.deacon@arm.com>
This patch defines the representation that will be used for the SVE
register state in the signal frame, and implements support for
saving and restoring the SVE registers around signals.
The same layout will also be used for the in-kernel task state.
Due to the variability of the SVE vector length, it is not possible
to define a fixed C struct to describe all the registers. Instead,
Macros are defined in sigcontext.h to facilitate access to the
parts of the structure.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Many user space API headers have licensing information, which is either
incomplete, badly formatted or just a shorthand for referring to the
license under which the file is supposed to be. This makes it hard for
compliance tools to determine the correct license.
Update these files with an SPDX license identifier. The identifier was
chosen based on the license information in the file.
GPL/LGPL licensed headers get the matching GPL/LGPL SPDX license
identifier with the added 'WITH Linux-syscall-note' exception, which is
the officially assigned exception identifier for the kernel syscall
exception:
NOTE! This copyright does *not* cover user programs that use kernel
services by normal system calls - this is merely considered normal use
of the kernel, and does *not* fall under the heading of "derived work".
This exception makes it possible to include GPL headers into non GPL
code, without confusing license compliance tools.
Headers which have either explicit dual licensing or are just licensed
under a non GPL license are updated with the corresponding SPDX
identifier and the GPLv2 with syscall exception identifier. The format
is:
((GPL-2.0 WITH Linux-syscall-note) OR SPDX-ID-OF-OTHER-LICENSE)
SPDX license identifiers are a legally binding shorthand, which can be
used instead of the full boiler plate text. The update does not remove
existing license information as this has to be done on a case by case
basis and the copyright holders might have to be consulted. This will
happen in a separate step.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne. See the previous patch in this series for the
methodology of how this patch was researched.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch defines an extra_context signal frame record that can be
used to describe an expanded signal frame, and modifies the context
block allocator and signal frame setup and parsing code to create,
populate, parse and decode this block as necessary.
To avoid abuse by userspace, parse_user_sigframe() attempts to
ensure that:
* no more than one extra_context is accepted;
* the extra context data is a sensible size, and properly placed
and aligned.
The extra_context data is required to start at the first 16-byte
aligned address immediately after the dummy terminator record
following extra_context in rt_sigframe.__reserved[] (as ensured
during signal delivery). This serves as a sanity-check that the
signal frame has not been moved or copied without taking the extra
data into account.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
[will: add __force annotation when casting extra_datap to __user pointer]
Signed-off-by: Will Deacon <will.deacon@arm.com>
This patch factors out the allocator for signal frame optional
records into a separate function, to ensure consistency and
facilitate later expansion.
No overrun checking is currently done, because the allocation is in
user memory and anyway the kernel never tries to allocate enough
space in the signal frame yet for an overrun to occur. This
behaviour will be refined in future patches.
The approach taken in this patch to allocation of the terminator
record is not very clean: this will also be replaced in subsequent
patches.
For future extension, a comment is added in sigcontext.h
documenting the current static allocations in __reserved[]. This
will be important for determining under what circumstances
userspace may or may not see an expanded signal frame.
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
I'm seeing this build failure for arm64:
CC [M] Documentation/filesystems/configfs/configfs_example_macros.o
In file included from /usr/include/bits/sigcontext.h:27:0,
from /usr/include/signal.h:340,
from /usr/include/sys/wait.h:30,
from Documentation/accounting/getdelays.c:24:
.../linux/usr/include/asm/sigcontext.h:61:2: error: unknown type name ‘u64’
u64 esr;
^
make[2]: *** [Documentation/accounting/getdelays] Error 1
This was introduced by commit 15af1942dd61ee23:
arm64: Expose ESR_EL1 information to user when SIGSEGV/SIGBUS
Using __u64 instead of u64 fixes the problem.
Signed-off-by: Mark Salter <msalter@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This information is useful for instruction emulators to detect
read/write and access size without having to decode the faulting
instruction. The current patch exports it via sigcontext (struct
esr_context) and is only valid for SIGSEGV and SIGBUS.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Michael Kerrisk <mtk.manpages@gmail.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>
Mark Brown