kernel/linux.git/tools/testing/selftests/vDSO, branch v6.12.80

selftests: vDSO: vdso_test_abi: Correctly skip whole test with missing vDSO

2025-10-15T09:59:59+00:00

[ Upstream commit 4b59a9f7628fd82b24f2148f62cf327a84d26555 ] If AT_SYSINFO_EHDR is missing the whole test needs to be skipped. Currently this results in the following output: TAP version 13 1..16 # AT_SYSINFO_EHDR is not present! This output is incorrect, as "1..16" still requires the subtest lines to be printed, which isn't done however. Switch to the correct skipping functions, so the output now correctly indicates that no subtests are being run: TAP version 13 1..0 # SKIP AT_SYSINFO_EHDR is not present! Fixes: 693f5ca08ca0 ("kselftest: Extend vDSO selftest") Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Link: https://lore.kernel.org/all/20250812-vdso-tests-fixes-v2-2-90f499dd35f8@linutronix.de Signed-off-by: Sasha Levin

selftests: vDSO: Fix -Wunitialized in powerpc VDSO_CALL() wrapper

2025-10-15T09:59:59+00:00

[ Upstream commit 9f15e0f9ef514b8e1a80707931f6d07362e8ebc4 ] The _rval register variable is meant to be an output operand of the asm statement but is instead used as input operand. clang 20.1 notices this and triggers -Wuninitialized warnings: tools/testing/selftests/timers/auxclock.c:154:10: error: variable '_rval' is uninitialized when used here [-Werror,-Wuninitialized] 154 | return VDSO_CALL(self->vdso_clock_gettime64, 2, clockid, ts); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ tools/testing/selftests/timers/../vDSO/vdso_call.h:59:10: note: expanded from macro 'VDSO_CALL' 59 | : "r" (_rval) \ | ^~~~~ tools/testing/selftests/timers/auxclock.c:154:10: note: variable '_rval' is declared here tools/testing/selftests/timers/../vDSO/vdso_call.h:47:2: note: expanded from macro 'VDSO_CALL' 47 | register long _rval asm ("r3"); \ | ^ It seems the list of input and output operands have been switched around. However as the argument registers are not always initialized they can not be marked as pure inputs as that would trigger -Wuninitialized warnings. Adding _rval as another input and output operand does also not work as it would collide with the existing _r3 variable. Instead reuse _r3 for both the argument and the return value. Fixes: 6eda706a535c ("selftests: vDSO: fix the way vDSO functions are called for powerpc") Reported-by: kernel test robot Signed-off-by: Thomas Weißschuh Signed-off-by: Thomas Gleixner Reviewed-by: Christophe Leroy Link: https://lore.kernel.org/all/20250812-vdso-tests-fixes-v2-1-90f499dd35f8@linutronix.de Closes: https://lore.kernel.org/oe-kbuild-all/202506180223.BOOk5jDK-lkp@intel.com/ Signed-off-by: Sasha Levin

selftests: vDSO: vdso_test_getrandom: Always print TAP header

2025-08-20T16:30:25+00:00

[ Upstream commit 1158220b24674edaf885433153deb4f0e5c7d331 ] 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 Signed-off-by: Sasha Levin

selftests: vDSO: chacha: Correctly skip test if necessary

2025-08-15T10:13:36+00:00

[ Upstream commit 2c0a4428f5d6005ff0db12057cc35273593fc040 ] According to kselftest.h ksft_exit_skip() is not meant to be called when a plan has already been printed. Use the recommended function ksft_test_result_skip(). This fixes a bug, where the TAP output would be invalid when skipping: TAP version 13 1..1 ok 2 # SKIP Not implemented on architecture The SKIP line should start with "ok 1" as the plan only contains one test. Fixes: 3b5992eaf730 ("selftests: vDSO: unconditionally build chacha test") 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-v3-1-e62e37a6bcf5@linutronix.de Signed-off-by: Sasha Levin

powerpc/vdso: Flag VDSO64 entry points as functions

2024-12-05T13:02:03+00:00

[ Upstream commit 0161bd38c24312853ed5ae9a425a1c41c4ac674a ] On powerpc64 as shown below by readelf, vDSO functions symbols have type NOTYPE. $ powerpc64-linux-gnu-readelf -a arch/powerpc/kernel/vdso/vdso64.so.dbg ELF Header: Magic: 7f 45 4c 46 02 02 01 00 00 00 00 00 00 00 00 00 Class: ELF64 Data: 2's complement, big endian Version: 1 (current) OS/ABI: UNIX - System V ABI Version: 0 Type: DYN (Shared object file) Machine: PowerPC64 Version: 0x1 ... Symbol table '.dynsym' contains 12 entries: Num: Value Size Type Bind Vis Ndx Name ... 1: 0000000000000524 84 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15 ... 4: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LINUX_2.6.15 5: 00000000000006c0 48 NOTYPE GLOBAL DEFAULT 8 __[...]@@LINUX_2.6.15 Symbol table '.symtab' contains 56 entries: Num: Value Size Type Bind Vis Ndx Name ... 45: 0000000000000000 0 OBJECT GLOBAL DEFAULT ABS LINUX_2.6.15 46: 00000000000006c0 48 NOTYPE GLOBAL DEFAULT 8 __kernel_getcpu 47: 0000000000000524 84 NOTYPE GLOBAL DEFAULT 8 __kernel_clock_getres To overcome that, commit ba83b3239e65 ("selftests: vDSO: fix vDSO symbols lookup for powerpc64") was applied to have selftests also look for NOTYPE symbols, but the correct fix should be to flag VDSO entry points as functions. The original commit that brought VDSO support into powerpc/64 has the following explanation: Note that the symbols exposed by the vDSO aren't "normal" function symbols, apps can't be expected to link against them directly, the vDSO's are both seen as if they were linked at 0 and the symbols just contain offsets to the various functions. This is done on purpose to avoid a relocation step (ppc64 functions normally have descriptors with abs addresses in them). When glibc uses those functions, it's expected to use it's own trampolines that know how to reach them. The descriptors it's talking about are the OPD function descriptors used on ABI v1 (big endian). But it would be more correct for a text symbol to have type function, even if there's no function descriptor for it. glibc has a special case already for handling the VDSO symbols which creates a fake opd pointing at the kernel symbol. So changing the VDSO symbol type to function shouldn't affect that. For ABI v2, there is no function descriptors and VDSO functions can safely have function type. So lets flag VDSO entry points as functions and revert the selftest change. Link: https://github.com/mpe/linux-fullhistory/commit/5f2dd691b62da9d9cc54b938f8b29c22c93cb805 Fixes: ba83b3239e65 ("selftests: vDSO: fix vDSO symbols lookup for powerpc64") Signed-off-by: Christophe Leroy Reviewed-By: Segher Boessenkool Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/b6ad2f1ee9887af3ca5ecade2a56f4acda517a85.1728512263.git.christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin

selftests: vDSO: Explicitly include sched.h

2024-10-08T21:48:09+00:00

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

2024-10-08T21:21:52+00:00

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

2024-10-08T21:21:36+00:00

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: unconditionally build chacha test

2024-10-08T21:21:29+00:00

Rather than using symlinks to find the vgetrandom-chacha.S file for each arch, store this in a file that uses the compiler to determine architecture, and then make use of weak symbols to skip the test on architectures that don't provide the code. Signed-off-by: Jason A. Donenfeld Signed-off-by: Shuah Khan

selftests: vDSO: align getrandom states to cache line

2024-10-01T14:30:58+00:00

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