linux/tools/testing
Thomas Weißschuh 9f15e0f9ef selftests: vDSO: Fix -Wunitialized in powerpc VDSO_CALL() wrapper
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: 6eda706a53 ("selftests: vDSO: fix the way vDSO functions are called for powerpc")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
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/
2025-09-09 10:57:38 +02:00
..
crypto/chacha20-s390
cxl cxl for v6.17 2025-08-01 15:47:06 -07:00
fault-injection
ktest ktest.pl: Add new PATCHCHECK_SKIP option to skip testing individual commits 2025-07-29 09:30:08 -04:00
kunit Revert "kunit: configs: Enable CONFIG_INIT_STACK_ALL_PATTERN in all_tests" 2025-06-03 11:20:21 +02:00
memblock
nvdimm mm: remove callers of pfn_t functionality 2025-07-09 22:42:19 -07:00
radix-tree tools/testing/radix-tree: test maple tree chaining mas_preallocate() calls 2025-07-09 22:42:12 -07:00
rbtree
scatterlist
selftests selftests: vDSO: Fix -Wunitialized in powerpc VDSO_CALL() wrapper 2025-09-09 10:57:38 +02:00
shared tools/testing: add linux/args.h header and fix radix, VMA tests 2025-08-19 16:35:54 -07:00
vma Significant patch series in this pull request: 2025-08-05 16:02:07 +03:00
vsock vsock/test: fix vsock_ioctl_int() check for unsupported ioctl 2025-07-16 16:14:00 -07:00