Indexing with mm_cid is incompatible with skipping disallowed cpumask,
because concurrency IDs are based on a virtual ID allocation which is
unrelated to the physical CPU mask.
These issues can be reproduced by running the rseq selftests under a
taskset which excludes CPU 0, e.g.
taskset -c 10-20 ./run_param_test.sh
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
When building with Clang, I am getting many warnings from the selftests/rseq tree.
Here's one such example from rseq tree:
| param_test.c🔢10: error: address argument to atomic operation must be a pointer to _Atomic type ('intptr_t *' (aka 'long *') invalid)
| 1234 | while (!atomic_load(&args->percpu_list_ptr)) {}
| | ^ ~~~~~~~~~~~~~~~~~~~~~~
| /usr/local/google/home/justinstitt/repos/tc-build/build/llvm/final/lib/clang/18/include/stdatomic.h:140:29: note: expanded from macro 'atomic_load'
| 140 | #define atomic_load(object) __c11_atomic_load(object, __ATOMIC_SEQ_CST)
| | ^ ~~~~~~
Use compiler builtins `__atomic_load_n()` and `__atomic_store_n()` with
accompanying __ATOMIC_ACQUIRE and __ATOMIC_RELEASE, respectively. This
will fix the warnings because the compiler builtins do not expect their
arguments to have _Atomic type. This should also make TSAN happier.
Link: https://github.com/ClangBuiltLinux/linux/issues/1698
Link: https://github.com/ClangBuiltLinux/continuous-integration2/issues/61
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
This Kselftest update for Linux 6.6-rc1 consists of a mix of fixes,
enhancements, and new tests. Bulk of the changes enhance and fix
rseq and resctrl tests. In addition, user_events, dmabuf-heaps and
perf_events are added to default kselftest build and test coverage.
A futex test fix, enhance prctl test coverage, and minor fixes are
included in this update.
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Merge tag 'linux-kselftest-next-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest
Pull Kselftest updates from Shuah Khan:
"A mix of fixes, enhancements, and new tests. Bulk of the changes
enhance and fix rseq and resctrl tests.
In addition, user_events, dmabuf-heaps and perf_events are added to
default kselftest build and test coverage. A futex test fix, enhance
prctl test coverage, and minor fixes are included in this update"
* tag 'linux-kselftest-next-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (32 commits)
selftests: cachestat: use proper syscall number macro
selftests: cachestat: properly link in librt
selftests/futex: Order calls to futex_lock_pi
selftests: Hook more tests into the build infrastructure
selftests/user_events: Reenable build
selftests/filesystems: Add six consecutive 'x' characters to mktemp
selftests/rseq: Use rseq_unqual_scalar_typeof in macros
selftests/rseq: Fix arm64 buggy load-acquire/store-release macros
selftests/rseq: Implement rseq_unqual_scalar_typeof
selftests/rseq: Fix CID_ID typo in Makefile
selftests:prctl: add set-process-name to .gitignore
selftests:prctl: Fix make clean override warning
selftests/resctrl: Remove test type checks from cat_val()
selftests/resctrl: Pass the real number of tests to show_cache_info()
selftests/resctrl: Move CAT/CMT test global vars to function they are used in
selftests/resctrl: Don't use variable argument list for ->setup()
selftests/resctrl: Don't pass test name to fill_buf
selftests/resctrl: Improve parameter consistency in fill_buf
selftests/resctrl: Remove unnecessary startptr global from fill_buf
selftests/resctrl: Remove "malloc_and_init_memory" param from run_fill_buf()
...
Use rseq_unqual_scalar_typeof() rather than typeof() in macros to remove
the volatile qualifier (if there is one in the input argument), thus
generating better assembly code in those scenarios.
Also add extra brackets around the "p" parameter in RSEQ_READ_ONCE(),
RSEQ_WRITE_ONCE(), and rseq_unqual_scalar_typeof() across architectures
to preserve expectations of operator priority. Here is an example that
shows how operator priority may be an issue with missing parentheses:
#define m(p) \
do { \
__typeof__(*p) v = 0; \
} while (0)
void fct(unsigned long long *p1)
{
m(p1 + 1); /* works */
m(1 + p1); /* broken */
}
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The arm64 load-acquire/store-release macros from the Linux kernel rseq
selftests are buggy. Remplace them by a working implementation.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Allow defining variables and perform cast with a typeof which removes
the volatile and const qualifiers.
This prevents declaring a stack variable with a volatile qualifier
within a macro, which would generate sub-optimal assembler.
This is imported from the "librseq" project.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Ensure that the basic percpu ops tests are effectively built against
mm_cid.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Commit 3bcbc20942 ("selftests/rseq: Play nice with binaries statically
linked against glibc 2.35+") which is now in Linus' tree introduced uses
of __weak but did nothing to ensure that a definition is provided for it
resulting in build failures for the rseq tests:
rseq.c:41:1: error: unknown type name '__weak'
__weak ptrdiff_t __rseq_offset;
^
rseq.c:41:17: error: expected ';' after top level declarator
__weak ptrdiff_t __rseq_offset;
^
;
rseq.c:42:1: error: unknown type name '__weak'
__weak unsigned int __rseq_size;
^
rseq.c:43:1: error: unknown type name '__weak'
__weak unsigned int __rseq_flags;
Fix this by using the definition from tools/include compiler.h.
Fixes: 3bcbc20942 ("selftests/rseq: Play nice with binaries statically linked against glibc 2.35+")
Signed-off-by: Mark Brown <broonie@kernel.org>
Message-Id: <20230804-kselftest-rseq-build-v1-1-015830b66aa9@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
To allow running rseq and KVM's rseq selftests as statically linked
binaries, initialize the various "trampoline" pointers to point directly
at the expect glibc symbols, and skip the dlysm() lookups if the rseq
size is non-zero, i.e. the binary is statically linked *and* the libc
registered its own rseq.
Define weak versions of the symbols so as not to break linking against
libc versions that don't support rseq in any capacity.
The KVM selftests in particular are often statically linked so that they
can be run on targets with very limited runtime environments, i.e. test
machines.
Fixes: 233e667e1a ("selftests/rseq: Uplift rseq selftests for compatibility with glibc-2.35")
Cc: Aaron Lewis <aaronlewis@google.com>
Cc: kvm@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-Id: <20230721223352.2333911-1-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Use $(KHDR_INCLUDES) as lookup path for kernel headers. This prevents
building against kernel headers from the build environment in scenarios
where kernel headers are installed into a specific output directory
(O=...).
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: <stable@vger.kernel.org> # 5.18+
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
The mm_numa_cid related rseq patches from the series were not picked up
into the tip tree, so enabling the mm_numa_cid test needs to be
reverted.
This reverts commit b344b8f2d8.
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/oe-lkp/202301040903.2dd1e25b-oliver.sang@intel.com
Adapt to the rseq.h API changes introduced by commits
"selftests/rseq: <arch>: Template memory ordering and percpu access mode".
Build a new param_test_mm_cid, param_test_mm_cid_benchmark, and
param_test_mm_cid_compare_twice executables to test the new "mm_cid"
rseq field.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-20-mathieu.desnoyers@efficios.com
Adapt to the rseq.h API changes introduced by commits
"selftests/rseq: <arch>: Template memory ordering and percpu access mode".
Build a new basic_percpu_ops_mm_cid_test to test the new "mm_cid" rseq
field.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-19-mathieu.desnoyers@efficios.com
Introduce a rseq-riscv-bits.h template header which is internally included
to generate the static inline functions covering:
- relaxed and release memory ordering,
- per-cpu-id and per-mm-cid per-cpu data access.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-18-mathieu.desnoyers@efficios.com
Introduce a rseq-s390-bits.h template header which is internally included
to generate the static inline functions covering:
- relaxed and release memory ordering,
- per-cpu-id and per-mm-cid per-cpu data access.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-17-mathieu.desnoyers@efficios.com
Introduce a rseq-ppc-bits.h template header which is internally included
to generate the static inline functions covering:
- relaxed and release memory ordering,
- per-cpu-id and per-mm-cid per-cpu data access.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-16-mathieu.desnoyers@efficios.com
Introduce a rseq-mips-bits.h template header which is internally
included to generate the static inline functions covering:
- relaxed and release memory ordering,
- per-cpu-id and per-mm-cid per-cpu data access.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-15-mathieu.desnoyers@efficios.com
Introduce a rseq-arm64-bits.h template header which is internally
included to generate the static inline functions covering:
- relaxed and release memory ordering,
- per-cpu-id and per-mm-cid per-cpu data access.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-14-mathieu.desnoyers@efficios.com
Introduce a rseq-arm-bits.h template header which is internally included
to generate the static inline functions covering:
- relaxed and release memory ordering,
- per-cpu-id and per-mm-cid per-cpu data access.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-13-mathieu.desnoyers@efficios.com
Introduce a rseq-x86-bits.h template header which is internally included
to generate the static inline functions covering:
- relaxed and release memory ordering,
- per-cpu-id and per-mm-cid per-cpu data access.
This introduces changes to the rseq.h selftests API which require to
update the rseq selftest programs. Similar API/templating changes need
to be done for other architectures.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-12-mathieu.desnoyers@efficios.com
This code is not currently build by the test Makefile, adds complexity,
and is not overall useful considering that the abort handling loops to
retry the fast-path.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-10-mathieu.desnoyers@efficios.com
Test the NUMA node id extension rseq field. Compare it against the value
returned by the getcpu(2) system call while pinned on a specific core.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-7-mathieu.desnoyers@efficios.com
When linking the selftests against a libc which does not handle rseq
registration (before 2.35), rseq thread registration silently succeed
even with CONFIG_RSEQ=n because it erroneously thinks that libc is
handling rseq registration.
This is caused by setting the rseq ownership flag only after the
rseq_available() check. It should rather be set before the
rseq_available() check.
Set the rseq_size to 0 (error value) immediately after the
rseq_available() check fails rather than in the thread registration
functions.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221122203932.231377-2-mathieu.desnoyers@efficios.com
When checking for libc rseq support in the library constructor, don't
only depend on the symbols presence, check that the registration was
completed.
This targets a scenario where the libc has rseq support but it is not
wired for the current architecture in 'bits/rseq.h', we want to fallback
to our internal registration mechanism.
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/20220614154830.1367382-4-mjeanson@efficios.com
This header is also used in librseq where it can be included in C++
code, add a space between literals and string macros.
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/20220614154830.1367382-3-mjeanson@efficios.com
Make the RISC-V rseq selftests compatible with glibc-2.35 by using the
rseq_get_abi() helper.
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/20220614154830.1367382-2-mjeanson@efficios.com
* Support for Sv57-based virtual memory.
* Various improvements for the MicroChip PolarFire SOC and the
associated Icicle dev board, which should allow upstream kernels to
boot without any additional modifications.
* An improved memmove() implementation.
* Support for the new Ssconfpmf and SBI PMU extensions, which allows for
a much more useful perf implementation on RISC-V systems.
* Support for restartable sequences.
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Merge tag 'riscv-for-linus-5.18-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Palmer Dabbelt:
- Support for Sv57-based virtual memory.
- Various improvements for the MicroChip PolarFire SOC and the
associated Icicle dev board, which should allow upstream kernels to
boot without any additional modifications.
- An improved memmove() implementation.
- Support for the new Ssconfpmf and SBI PMU extensions, which allows
for a much more useful perf implementation on RISC-V systems.
- Support for restartable sequences.
* tag 'riscv-for-linus-5.18-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (36 commits)
rseq/selftests: Add support for RISC-V
RISC-V: Add support for restartable sequence
MAINTAINERS: Add entry for RISC-V PMU drivers
Documentation: riscv: Remove the old documentation
RISC-V: Add sscofpmf extension support
RISC-V: Add perf platform driver based on SBI PMU extension
RISC-V: Add RISC-V SBI PMU extension definitions
RISC-V: Add a simple platform driver for RISC-V legacy perf
RISC-V: Add a perf core library for pmu drivers
RISC-V: Add CSR encodings for all HPMCOUNTERS
RISC-V: Remove the current perf implementation
RISC-V: Improve /proc/cpuinfo output for ISA extensions
RISC-V: Do no continue isa string parsing without correct XLEN
RISC-V: Implement multi-letter ISA extension probing framework
RISC-V: Extract multi-letter extension names from "riscv, isa"
RISC-V: Minimal parser for "riscv, isa" strings
RISC-V: Correctly print supported extensions
riscv: Fixed misaligned memory access. Fixed pointer comparison.
MAINTAINERS: update riscv/microchip entry
riscv: dts: microchip: add new peripherals to icicle kit device tree
...
Add support for RISC-V in the rseq selftests, which covers both
64-bit and 32-bit ISA with little endian mode.
Signed-off-by: Vincent Chen <vincent.chen@sifive.com>
Tested-by: Eric Lin <eric.lin@sifive.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Just before the 2.35 release of glibc, the __rseq_offset userspace ABI
was changed from int to ptrdiff_t.
Adapt to this change in the kernel selftests.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://sourceware.org/pipermail/libc-alpha/2022-February/136024.html
Rather than use rseq_get_abi() and pass its result through a register to
the inline assembler, directly access the per-thread rseq area through a
memory reference combining the %gs segment selector, the constant offset
of the field in struct rseq, and the rseq_offset value (in a register).
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-16-mathieu.desnoyers@efficios.com
Rather than use rseq_get_abi() and pass its result through a register to
the inline assembler, directly access the per-thread rseq area through a
memory reference combining the %fs segment selector, the constant offset
of the field in struct rseq, and the rseq_offset value (in a register).
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-15-mathieu.desnoyers@efficios.com
The arm and mips work-around for asm goto size guess issues are not
properly documented, and lack reference to specific compiler versions,
upstream compiler bug tracker entry, and reproducer.
I can only find a loosely documented patch in my original LKML rseq post
refering to gcc < 7 on ARM, but it does not appear to be sufficient to
track the exact issue. Also, I am not sure MIPS really has the same
limitation.
Therefore, remove the work-around until we can properly document this.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/20171121141900.18471-17-mathieu.desnoyers@efficios.com/
The semantic of off_t is for file offsets. We mean to use it as an
offset from a pointer. We really expect it to fit in a single register,
and not use a 64-bit type on 32-bit architectures.
Fix runtime issues on ppc32 where the offset is always 0 due to
inconsistency between the argument type (off_t -> 64-bit) and type
expected by the inline assembler (32-bit).
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-11-mathieu.desnoyers@efficios.com
Building the rseq basic test with
gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.12)
Target: powerpc-linux-gnu
leads to these errors:
/tmp/ccieEWxU.s: Assembler messages:
/tmp/ccieEWxU.s:118: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:118: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:121: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:121: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:626: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:626: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:629: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:629: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:735: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:735: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:738: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:738: Error: junk at end of line: `,8'
/tmp/ccieEWxU.s:741: Error: syntax error; found `,', expected `('
/tmp/ccieEWxU.s:741: Error: junk at end of line: `,8'
Makefile:581: recipe for target 'basic_percpu_ops_test.o' failed
Based on discussion with Linux powerpc maintainers and review of
the use of the "m" operand in powerpc kernel code, add the missing
%Un%Xn (where n is operand number) to the lwz, stw, ld, and std
instructions when used with "m" operands.
Using "WORD" to mean either a 32-bit or 64-bit type depending on
the architecture is misleading. The term "WORD" really means a
32-bit type in both 32-bit and 64-bit powerpc assembler. The intent
here is to wrap load/store to intptr_t into common macros for both
32-bit and 64-bit.
Rename the macros with a RSEQ_ prefix, and use the terms "INT"
for always 32-bit type, and "LONG" for architecture bitness-sized
type.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-10-mathieu.desnoyers@efficios.com
ppc32 incorrectly uses padding as rseq_cs pointer field. Fix this by
using the rseq_cs.arch.ptr field.
Use this field across all architectures.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-9-mathieu.desnoyers@efficios.com
glibc-2.35 (upcoming release date 2022-02-01) exposes the rseq per-thread
data in the TCB, accessible at an offset from the thread pointer, rather
than through an actual Thread-Local Storage (TLS) variable, as the
Linux kernel selftests initially expected.
The __rseq_abi TLS and glibc-2.35's ABI for per-thread data cannot
actively coexist in a process, because the kernel supports only a single
rseq registration per thread.
Here is the scheme introduced to ensure selftests can work both with an
older glibc and with glibc-2.35+:
- librseq exposes its own "rseq_offset, rseq_size, rseq_flags" ABI.
- librseq queries for glibc rseq ABI (__rseq_offset, __rseq_size,
__rseq_flags) using dlsym() in a librseq library constructor. If those
are found, copy their values into rseq_offset, rseq_size, and
rseq_flags.
- Else, if those glibc symbols are not found, handle rseq registration
from librseq and use its own IE-model TLS to implement the rseq ABI
per-thread storage.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-8-mathieu.desnoyers@efficios.com
This is done in preparation for the selftest uplift to become compatible
with glibc-2.35.
glibc-2.35 exposes the rseq per-thread data in the TCB, accessible
at an offset from the thread pointer.
The toolchains do not implement accessing the thread pointer on all
architectures. Provide thread pointer getters for ppc and x86 which
lack (or lacked until recently) toolchain support.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-7-mathieu.desnoyers@efficios.com
This is done in preparation for the selftest uplift to become compatible
with glibc-2.35.
glibc-2.35 exposes the rseq per-thread data in the TCB, accessible
at an offset from the thread pointer, rather than through an actual
Thread-Local Storage (TLS) variable, as the kernel selftests initially
expected.
Introduce a rseq_get_abi() helper, initially using the __rseq_abi
TLS variable, in preparation for changing this userspace ABI for one
which is compatible with glibc-2.35.
Note that the __rseq_abi TLS and glibc-2.35's ABI for per-thread data
cannot actively coexist in a process, because the kernel supports only
a single rseq registration per thread.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-6-mathieu.desnoyers@efficios.com
This is done in preparation for the selftest uplift to become compatible
with glibc-2.35.
All accesses to the __rseq_abi fields are volatile, but remove the
volatile from the TLS variable declaration, otherwise we are stuck with
volatile for the upcoming rseq_get_abi() helper.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-5-mathieu.desnoyers@efficios.com
The Linux kernel rseq uapi header has a broken layout for the
rseq_cs.ptr field on 32-bit little endian architectures. The entire
rseq_cs.ptr field is planned for removal, leaving only the 64-bit
rseq_cs.ptr64 field available.
Both glibc and librseq use their own copy of the Linux kernel uapi
header, where they introduce proper union fields to access to the 32-bit
low order bits of the rseq_cs pointer on 32-bit architectures.
Introduce a copy of the Linux kernel uapi headers in the Linux kernel
selftests.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220124171253.22072-2-mathieu.desnoyers@efficios.com
ARRAY_SIZE is defined in several selftests. Remove definitions from
individual test files and include header file for the define instead.
ARRAY_SIZE define is added in a separate patch to prepare for this
change.
Remove ARRAY_SIZE from rseq tests and pickup the one defined in
kselftest.h.
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Except arch x86, the function rseq_offset_deref_addv is not defined.
The function test_membarrier_manager_thread call rseq_offset_deref_addv
produces a build error.
The RSEQ_ARCH_HAS_OFFSET_DEREF_ADD should contain all the code
for the MEMBARRIER_CMD_PRIVATE_EXPEDITED_RSEQ.
If the other Arch implements this feature,
defined RSEQ_ARCH_HAS_OFFSET_DEREF_ADD in the header file
to ensure that this feature is available.
Following build errors:
param_test.c: In function ‘test_membarrier_worker_thread’:
param_test.c:1164:10: warning: implicit declaration of function ‘rseq_offset_deref_addv’
ret = rseq_offset_deref_addv(&args->percpu_list_ptr,
^~~~~~~~~~~~~~~~~~~~~~
/tmp/ccMj9yHJ.o: In function `test_membarrier_worker_thread':
param_test.c:1164: undefined reference to `rseq_offset_deref_addv'
param_test.c:1164: undefined reference to `rseq_offset_deref_addv'
collect2: error: ld returned 1 exit status
make: *** [/selftests/rseq/param_test_benchmark] Error 1
Signed-off-by: Xingxing Su <suxingxing@loongson.cn>
Acked-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
