kernel/tools/testing/selftests/rseq/rseq-s390.h, branch linux-rolling-stable

tools: Remove s390 compat support

2025-11-17T10:10:38Z

Remove s390 compat support from everything within tools, since s390 compat support will be removed from the kernel. Reviewed-by: Arnd Bergmann Acked-by: Thomas Weißschuh # tools/nolibc selftests/nolibc Reviewed-by: Thomas Weißschuh # selftests/vDSO Acked-by: Alexei Starovoitov # bpf bits Signed-off-by: Heiko Carstens

selftests/rseq: Use rseq_unqual_scalar_typeof in macros

2023-08-08T20:42:12Z

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 Cc: Peter Zijlstra Signed-off-by: Shuah Khan

selftests/rseq: s390: Template memory ordering and percpu access mode

2022-12-27T11:52:14Z

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 Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20221122203932.231377-17-mathieu.desnoyers@efficios.com

selftests/rseq: Remove RSEQ_SKIP_FASTPATH code

2022-12-27T11:52:12Z

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 Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20221122203932.231377-10-mathieu.desnoyers@efficios.com

selftests/rseq: Fix: work-around asm goto compiler bugs

2022-02-02T12:11:37Z

gcc and clang each have their own compiler bugs with respect to asm goto. Implement a work-around for compiler versions known to have those bugs. gcc prior to 4.8.2 miscompiles asm goto. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 gcc prior to 8.1.0 miscompiles asm goto at O1. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103908 clang prior to version 13.0.1 miscompiles asm goto at O2. https://github.com/llvm/llvm-project/issues/52735 Work around these issues by adding a volatile inline asm with memory clobber in the fallthrough after the asm goto and at each label target. Emit this for all compilers in case other similar issues are found in the future. Signed-off-by: Mathieu Desnoyers Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220124171253.22072-14-mathieu.desnoyers@efficios.com

selftests/rseq: Fix ppc32 offsets by using long rather than off_t

2022-02-02T12:11:36Z

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 Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220124171253.22072-11-mathieu.desnoyers@efficios.com

selftests/rseq: Fix ppc32: wrong rseq_cs 32-bit field pointer on big endian

2022-02-02T12:11:35Z

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 Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220124171253.22072-9-mathieu.desnoyers@efficios.com

selftests/rseq: Introduce rseq_get_abi() helper

2022-02-02T12:11:35Z

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 Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220124171253.22072-6-mathieu.desnoyers@efficios.com

Merge tag 'linux-kselftest-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

2019-05-17T01:57:58Z

Pull more kselftest updates from Shuah Khan: - kselftest framework bpf build/test workflow regression fix - Fix to kselftest install to use default install path - Fix to kselftest KBUILD_OUTPUT builds to not clutter main KBUILD_OUTPUT directory with selftest objects - .gitignore fixes (Kelsey Skunberg) - rseq selftests updates (Mathieu Desnoyers and Martin Schwidefsky) They change the per-architecture pre-abort signatures to ensure those are valid trap instructions. The way exit points are presented to debuggers is enhanced, ensuring all exit points are present, so debuggers don't have to disassemble rseq critical section to properly skip over them. Discussions with the glibc community is reaching a consensus of exposing a __rseq_handled symbol from glibc to coexist with rseq early adopters. Update the rseq selftest code to expose and use this symbol. Support for compiling asm goto with clang is added with the "-no-integrated-as" compiler switch, similarly to the top level kernel Makefile. - kselftest Makefile test run output refactoring and making test output TAP13 compliant from Kees Cook: This re-factors the selftest Makefiles to extract the test running logic to be reused between "run_tests" and "emit_tests", while also fixing up the test output to be TAP version 13 compliant: - added "plan" line - fixed result line syntax - moved all test output to be "# "-prefixed as TAP "diagnostic" lines The prefixing code includes a fallback mode for limited execution environments. Additionally, the plan lines are fixed for all callers of kselftest.h. * tag 'linux-kselftest-5.2-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (25 commits) selftests: avoid KBUILD_OUTPUT dir cluttering with selftest objects selftests: drivers: Create .gitignore to include /dma-buf/udmabuf selftests: pidfd: Create .gitignore to include pidfd_test selftests: fix bpf build/test workflow regression when KBUILD_OUTPUT is set selftests: fix install target to use default install path rseq/selftests: add -no-integrated-as for clang rseq/selftests: mips: use break instruction for RSEQ_SIG rseq/selftests: powerpc code signature: generate valid instructions rseq/selftests: aarch64 code signature: handle big-endian environment rseq/selftests: arm: use udf instruction for RSEQ_SIG rseq/selftests: s390: use trap4 for RSEQ_SIG rseq/selftests: x86: use ud1 instruction as RSEQ_SIG opcode rseq/selftests: s390: use jg instruction for jumps outside of the asm rseq/selftests: Use __rseq_handled symbol to coexist with glibc rseq/selftests: Introduce __rseq_cs_ptr_array, rename __rseq_table to __rseq_cs rseq/selftests: Add __rseq_exit_point_array section for debuggers rseq/selftests: x86: Work-around bogus gcc-8 optimisation selftests: Add test plan API to kselftest.h and adjust callers selftests: Remove KSFT_TAP_LEVEL selftests: Move test output to diagnostic lines ...

rseq/selftests: s390: use trap4 for RSEQ_SIG

2019-05-07T21:32:14Z

Use trap4 as the guard instruction for the restartable sequence abort handler. Signed-off-by: Martin Schwidefsky Signed-off-by: Mathieu Desnoyers Signed-off-by: Shuah Khan