kernel/tools/testing/selftests/vDSO/vdso_test_getrandom.c, branch linux-rolling-stable

selftests: complete kselftest include centralization

2025-11-27T22:24:31Z

This follow-up patch completes centralization of kselftest.h and ksefltest_harness.h includes in remaining seltests files, replacing all relative paths with a non-relative paths using shared -I include path in lib.mk Tested with gcc-13.3 and clang-18.1, and cross-compiled successfully on riscv, arm64, x86_64 and powerpc arch. [reddybalavignesh9979@gmail.com: add selftests include path for kselftest.h] Link: https://lkml.kernel.org/r/20251017090201.317521-1-reddybalavignesh9979@gmail.com Link: https://lkml.kernel.org/r/20251016104409.68985-1-reddybalavignesh9979@gmail.com Signed-off-by: Bala-Vignesh-Reddy Suggested-by: Andrew Morton Link: https://lore.kernel.org/lkml/20250820143954.33d95635e504e94df01930d0@linux-foundation.org/ Reviewed-by: Wei Yang Cc: David Hildenbrand Cc: David S. Miller Cc: Eric Dumazet Cc: Günther Noack Cc: Jakub Kacinski Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mickael Salaun Cc: Ming Lei Cc: Paolo Abeni Cc: Shuah Khan Cc: Simon Horman Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

selftests: vDSO: vdso_test_getrandom: Always print TAP header

2025-07-01T13:50:42Z

The TAP specification requires that the output begins with a header line. If vgetrandom_init() fails and skips the test, that header line is missing. Call vgetrandom_init() after ksft_print_header(). Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Reviewed-by: Muhammad Usama Anjum Link: https://lore.kernel.org/all/20250611-selftests-vdso-fixes-v3-8-e62e37a6bcf5@linutronix.de

selftests: vDSO: vdso_test_getrandom: Avoid -Wunused

2025-07-01T13:50:42Z

vgetrandom_put_state() and the variable "ret" in kselftest() are unused. Drop the variable "ret". Suppress the warning for vgetrandom_put_state() as it is meant as an example for libc implementors. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250611-selftests-vdso-fixes-v3-4-e62e37a6bcf5@linutronix.de

selftests: vDSO: vdso_test_getrandom: Drop unused include of linux/compiler.h

2025-07-01T13:50:42Z

The header is unused. Furthermore this is not a real UAPI header, but only exists in tools/include/. This prevents building the selftest against real UAPI headers. Drop the include. Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250611-selftests-vdso-fixes-v3-3-e62e37a6bcf5@linutronix.de

selftests: vDSO: Explicitly include sched.h

2024-10-08T21:48:09Z

The previous commit introduced the use of CLONE_NEWTIME without including which contains its definition. Add an explicit include of to ensure that CLONE_NEWTIME is correctly defined before it is used. Fixes: 2aec90036dcd ("selftests: vDSO: ensure vgetrandom works in a time namespace") Signed-off-by: Yu Liao Signed-off-by: Shuah Khan

selftests: vDSO: improve getrandom and chacha error messages

2024-10-08T21:21:52Z

Improve the error and skip condition messages to let the developer know precisely where a test has failed. Also make better use of the ksft api for this. Signed-off-by: Jason A. Donenfeld Signed-off-by: Shuah Khan

selftests: vDSO: unconditionally build getrandom test

2024-10-08T21:21:36Z

Rather than building on supported archs, build on all archs, and then use the presence of the symbol in the vDSO to either skip the test or move forward with it. Note that this means that this test no longer checks whether the symbol was correctly added to the kernel. But hopefully this will be clear enough to developers and we'll cross our fingers that symbols aren't removed by accident and not caught after this change. Signed-off-by: Jason A. Donenfeld Signed-off-by: Shuah Khan

selftests: vDSO: align getrandom states to cache line

2024-10-01T14:30:58Z

This prevents false sharing, which makes a large difference on machines with several NUMA nodes, such as on a dual socket Intel(R) Xeon(R) Gold 6338 CPU @ 2.00GHz, where the "bench-multi" test goes from 2.7s down to 1.9s. While this is just test code, it also forms the basis of how folks will wind up implementing this in libraries, so we should implement this simple cache alignment improvement here. Suggested-by: Florian Weimer Cc: Adhemerval Zanella Signed-off-by: Jason A. Donenfeld Signed-off-by: Shuah Khan

selftests: vDSO: ensure vgetrandom works in a time namespace

2024-09-13T15:28:35Z

After verifying that vDSO getrandom does work, which ensures that the RNG is initialized, test to see if it also works inside of a time namespace. This is important to test, because the vvar pages get swizzled around there. If the arch code isn't careful, the RNG will appear uninitialized inside of a time namespace. Because broken code makes the RNG appear uninitialized, test that everything works by issuing a call to vgetrandom from a fork in a time namespace, and use ptrace to ensure that the actual syscall getrandom doesn't get called. If it doesn't get called, then the test succeeds. Signed-off-by: Jason A. Donenfeld

selftests: vDSO: quash clang omitted parameter warning in getrandom test

2024-08-30T15:55:41Z

When building with clang, there's this warning: vdso_test_getrandom.c:145:40: warning: omitting the parameter name in a function definition is a C23 extension [-Wc23-extensions] 145 | static void *test_vdso_getrandom(void *) | ^ vdso_test_getrandom.c:155:40: warning: omitting the parameter name in a function definition is a C23 extension [-Wc23-extensions] 155 | static void *test_libc_getrandom(void *) | ^ vdso_test_getrandom.c:165:43: warning: omitting the parameter name in a function definition is a C23 extension [-Wc23-extensions] 165 | static void *test_syscall_getrandom(void *) Add the named ctx parameter to quash it. Reported-by: Mark Brown Reviewed-by: Mark Brown Signed-off-by: Jason A. Donenfeld