kernel/linux.git/tools/testing/selftests/rseq, branch v6.6.132

rseq/selftests: Use weak symbol reference, not definition, to link with glibc

2025-10-19T14:30:53+00:00

commit a001cd248ab244633c5fabe4f7c707e13fc1d1cc upstream. Add "extern" to the glibc-defined weak rseq symbols to convert the rseq selftest's usage from weak symbol definitions to weak symbol _references_. Effectively re-defining the glibc symbols wreaks havoc when building with -fno-common, e.g. generates segfaults when running multi-threaded programs, as dynamically linked applications end up with multiple versions of the symbols. Building with -fcommon, which until recently has the been the default for GCC and clang, papers over the bug by allowing the linker to resolve the weak/tentative definition to glibc's "real" definition. Note, the symbol itself (or rather its address), not the value of the symbol, is set to 0/NULL for unresolved weak symbol references, as the symbol doesn't exist and thus can't have a value. Check for a NULL rseq size pointer to handle the scenario where the test is statically linked against a libc that doesn't support rseq in any capacity. Fixes: 3bcbc20942db ("selftests/rseq: Play nice with binaries statically linked against glibc 2.35+") Reported-by: Thomas Gleixner Suggested-by: Florian Weimer Signed-off-by: Sean Christopherson Signed-off-by: Thomas Gleixner Reviewed-by: Mathieu Desnoyers Cc: stable@vger.kernel.org Closes: https://lore.kernel.org/all/87frdoybk4.ffs@tglx Signed-off-by: Greg Kroah-Hartman

rseq/selftests: Fix riscv rseq_offset_deref_addv inline asm

2025-03-07T15:45:48+00:00

commit 713e788c0e07e185fd44dd581f74855ef149722f upstream. 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: 171586a6ab66 ("selftests/rseq: riscv: Template memory ordering and percpu access mode") Signed-off-by: Stafford Horne Tested-by: Charlie Jenkins Reviewed-by: Charlie Jenkins Reviewed-by: Mathieu Desnoyers Acked-by: Shuah Khan Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250114170721.3613280-1-shorne@gmail.com Signed-off-by: Palmer Dabbelt Signed-off-by: Greg Kroah-Hartman

selftests/rseq: Fix handling of glibc without rseq support

2025-02-08T08:52:35+00:00

commit 336d02bc4c6bec5c3d933e5d470a94970f830957 upstream. 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: a0cc649353bb ("selftests/rseq: Fix mm_cid test failure") Reported-by: Raghavendra Rao Ananta Signed-off-by: Mathieu Desnoyers Cc: Raghavendra Rao Ananta Cc: Shuah Khan Cc: Peter Zijlstra Cc: Boqun Feng Cc: "Paul E. McKenney" Cc: Carlos O'Donell Cc: Florian Weimer Cc: Michael Jeanson Cc: linux-kselftest@vger.kernel.org Cc: stable@vger.kernel.org Signed-off-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman

selftests/rseq: Fix mm_cid test failure

2024-10-17T13:24:37+00:00

commit a0cc649353bb726d4aa0db60dce467432197b746 upstream. Adapt the rseq.c/rseq.h code to follow GNU C library changes introduced by: glibc commit 2e456ccf0c34 ("Linux: Make __rseq_size useful for feature detection (bug 31965)") Without this fix, rseq selftests for mm_cid fail: ./run_param_test.sh Default parameters Running test spinlock Running compare-twice test spinlock Running mm_cid test spinlock Error: cpu id getter unavailable Fixes: 18c2355838e7 ("selftests/rseq: Implement rseq mm_cid field support") Signed-off-by: Mathieu Desnoyers Cc: Peter Zijlstra CC: Boqun Feng CC: "Paul E. McKenney" Cc: Shuah Khan CC: Carlos O'Donell CC: Florian Weimer CC: linux-kselftest@vger.kernel.org CC: stable@vger.kernel.org Signed-off-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman

Merge tag 'linux-kselftest-next-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest

2023-08-29T01:46:47+00:00

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() ...

selftests/rseq: Use rseq_unqual_scalar_typeof in macros

2023-08-08T20:42:12+00:00

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: Fix arm64 buggy load-acquire/store-release macros

2023-08-08T20:42:06+00:00

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 Cc: Catalin Marinas Cc: Will Deacon Cc: Peter Zijlstra Signed-off-by: Shuah Khan

selftests/rseq: Implement rseq_unqual_scalar_typeof

2023-08-08T20:42:01+00:00

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 Signed-off-by: Shuah Khan

selftests/rseq: Fix CID_ID typo in Makefile

2023-08-08T20:41:54+00:00

Ensure that the basic percpu ops tests are effectively built against mm_cid. Signed-off-by: Mathieu Desnoyers Cc: Peter Zijlstra Signed-off-by: Shuah Khan

selftests/rseq: Fix build with undefined __weak

2023-08-04T22:10:29+00:00

Commit 3bcbc20942db ("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: 3bcbc20942db ("selftests/rseq: Play nice with binaries statically linked against glibc 2.35+") Signed-off-by: Mark Brown Message-Id: <20230804-kselftest-rseq-build-v1-1-015830b66aa9@kernel.org> Signed-off-by: Paolo Bonzini