diff options
| author | Linus Torvalds <torvalds@linux-foundation.org> | 2025-09-29 08:54:12 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-10-15 12:03:13 +0200 |
| commit | 5cd2217774476d7e6c85d55f3bf1a9cd4e730a3c (patch) | |
| tree | f495dab807de45bbb21dc32a23aa81904765499a /init | |
| parent | 9ad318d8655d26293cc23ad3fced185c61861dab (diff) | |
Fix CC_HAS_ASM_GOTO_OUTPUT on non-x86 architectures
[ Upstream commit fde0ab43b9a30d08817adc5402b69fec83a61cb8 ]
There's a silly problem with the CC_HAS_ASM_GOTO_OUTPUT test: even with
a working compiler it will fail on some architectures simply because it
uses the mnemonic "jmp" for testing the inline asm.
And as reported by Geert, not all architectures use that mnemonic, so
the test fails spuriously on such platforms (including arm and riscv,
but also several other architectures).
This issue avoided any obvious test failures because the build still
works thanks to falling back on the old non-asm-goto code, which just
generates worse code.
Just use an empty asm statement instead.
Reported-and-tested-by: Geert Uytterhoeven <geert@linux-m68k.org>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Fixes: e2ffa15b9baa ("kbuild: Disable CC_HAS_ASM_GOTO_OUTPUT on clang < 17")
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'init')
| -rw-r--r-- | init/Kconfig | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/init/Kconfig b/init/Kconfig index e5d6d798994a..87c868f86a06 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -102,7 +102,7 @@ config CC_HAS_ASM_GOTO_OUTPUT # Detect basic support depends on $(success,echo 'int foo(int x) { asm goto ("": "=r"(x) ::: bar); return x; bar: return 0; }' | $(CC) -x c - -c -o /dev/null) # Detect clang (< v17) scoped label issues - depends on $(success,echo 'void b(void **);void* c(void);int f(void){{asm goto("jmp %l0"::::l0);return 0;l0:return 1;}void *x __attribute__((cleanup(b)))=c();{asm goto("jmp %l0"::::l1);return 2;l1:return 3;}}' | $(CC) -x c - -c -o /dev/null) + depends on $(success,echo 'void b(void **);void* c(void);int f(void){{asm goto(""::::l0);return 0;l0:return 1;}void *x __attribute__((cleanup(b)))=c();{asm goto(""::::l1);return 2;l1:return 3;}}' | $(CC) -x c - -c -o /dev/null) config CC_HAS_ASM_GOTO_TIED_OUTPUT depends on CC_HAS_ASM_GOTO_OUTPUT |