llvm on s390 has problems with __builtin_return_address(n), with n>0, this results in a somewhat cryptic error message: fatal error: error in backend: Unsupported stack frame traversal count To work around it, use the direct return address directly. This is probably not ideal here, but gets things to compile and should only lead to inferior reporting, not to misbehavior of the generated code. Link: https://bugs.llvm.org/show_bug.cgi?id=41424 Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> --- arch/s390/include/asm/ftrace.h | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h index 5a3c95b11952..7923c63946fb 100644 --- a/arch/s390/include/asm/ftrace.h +++ b/arch/s390/include/asm/ftrace.h @@ -13,7 +13,12 @@ #ifndef __ASSEMBLY__ +#ifdef CONFIG_CC_IS_CLANG +/* https://bugs.llvm.org/show_bug.cgi?id=41424 */ +#define ftrace_return_address(n) __builtin_return_address(0) +#else #define ftrace_return_address(n) __builtin_return_address(n) +#endif void _mcount(void); void ftrace_caller(void); -- 2.20.0
