Adding the aligned(1024) attribute to the definition of __rseq_abi did
not increase its size to 1024, for this attribute to impact the size of
__rseq_abi it would need to be added to the declaration of 'struct
rseq_abi'. We only want to increase the size of the TLS allocation to
ensure registration will succeed with future extended ABI. Use a union
with a dummy member to ensure we allocate 1024 bytes.
Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://lore.kernel.org/r/20250311192222.323453-1-mjeanson@efficios.com
When working on OpenRISC support for restartable sequences I noticed
and fixed these two issues with the riscv support bits.
1 The 'inc' argument to RSEQ_ASM_OP_R_DEREF_ADDV was being implicitly
passed to the macro. Fix this by adding 'inc' to the list of macro
arguments.
2 The inline asm input constraints for 'inc' and 'off' use "er", The
riscv gcc port does not have an "e" constraint, this looks to be
copied from the x86 port. Fix this by just using an "r" constraint.
I have compile tested this only for riscv. However, the same fixes I
use in the OpenRISC rseq selftests and everything passes with no issues.
Fixes: 171586a6ab ("selftests/rseq: riscv: Template memory ordering and percpu access mode")
Signed-off-by: Stafford Horne <shorne@gmail.com>
Tested-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250114170721.3613280-1-shorne@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Pull OpenRISC updates from Stafford Horne:
- Added support for restartable sequences (me)
- Migration to Generic built-in DTB (Masahiro Yamada)
* tag 'for-linus' of https://github.com/openrisc/linux:
rseq/selftests: Add support for OpenRISC
openrisc: Add support for restartable sequences
openrisc: Add HAVE_REGS_AND_STACK_ACCESS_API support
openrisc: migrate to the generic rule for built-in DTB
When porting librseq commit:
commit c7b45750fa85 ("Adapt to glibc __rseq_size feature detection")
from librseq to the kernel selftests, the following line was missed
at the end of rseq_init():
rseq_size = get_rseq_kernel_feature_size();
which effectively leaves rseq_size initialized to -1U when glibc does not
have rseq support. glibc supports rseq from version 2.35 onwards.
In a following librseq commit
commit c67d198627c2 ("Only set 'rseq_size' on first thread registration")
to mimic the libc behavior, a new approach is taken: don't set the
feature size in 'rseq_size' until at least one thread has successfully
registered. This allows using 'rseq_size' in fast-paths to test for both
registration status and available features. The caveat is that on libc
either all threads are registered or none are, while with bare librseq
it is the responsability of the user to register all threads using rseq.
This combines the changes from the following librseq git commits:
commit c7b45750fa85 ("Adapt to glibc __rseq_size feature detection")
commit c67d198627c2 ("Only set 'rseq_size' on first thread registration")
Fixes: a0cc649353 ("selftests/rseq: Fix mm_cid test failure")
Reported-by: Raghavendra Rao Ananta <rananta@google.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Raghavendra Rao Ananta <rananta@google.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Carlos O'Donell <carlos@redhat.com>
Cc: Florian Weimer <fweimer@redhat.com>
Cc: Michael Jeanson <mjeanson@efficios.com>
Cc: linux-kselftest@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Add support for OpenRISC in the rseq selftests. OpenRISC is 32-bit
only.
Tested this with:
Compiler: gcc version 14.2.0 (GCC)
Binutils: GNU assembler version 2.43.1 (or1k-smh-linux-gnu) using BFD version (GNU Binutils) 2.43.1.20241207
Linux: Linux buildroot 6.13.0-rc2-00005-g1fa73dd6c2d3-dirty #213 SMP Sat Dec 28 22:18:39 GMT 2024 openrisc GNU/Linux
Glibc: 2024-12-13 e4e49583d9 Stafford Horne or1k: Update libm-test-ulps
Signed-off-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
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:1234:10: 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>
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>
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>
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>
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
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
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
...
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
