diff options
| -rw-r--r-- | arch/s390/include/asm/ftrace.h | 8 | ||||
| -rw-r--r-- | arch/s390/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/stacktrace.c | 19 |
3 files changed, 23 insertions, 6 deletions
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h index 621f23d5ae30..77e479d44f1e 100644 --- a/arch/s390/include/asm/ftrace.h +++ b/arch/s390/include/asm/ftrace.h @@ -8,12 +8,8 @@ #ifndef __ASSEMBLY__ -#ifdef CONFIG_CC_IS_CLANG -/* https://llvm.org/pr41424 */ -#define ftrace_return_address(n) 0UL -#else -#define ftrace_return_address(n) __builtin_return_address(n) -#endif +unsigned long return_address(unsigned int n); +#define ftrace_return_address(n) return_address(n) void ftrace_caller(void); diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index fa029d0dc28f..db2d9ba5a86d 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -11,6 +11,8 @@ CFLAGS_REMOVE_ftrace.o = $(CC_FLAGS_FTRACE) # Do not trace early setup code CFLAGS_REMOVE_early.o = $(CC_FLAGS_FTRACE) CFLAGS_REMOVE_rethook.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_stacktrace.o = $(CC_FLAGS_FTRACE) +CFLAGS_REMOVE_unwind_bc.o = $(CC_FLAGS_FTRACE) endif diff --git a/arch/s390/kernel/stacktrace.c b/arch/s390/kernel/stacktrace.c index 94f440e38303..7c294da45bf5 100644 --- a/arch/s390/kernel/stacktrace.c +++ b/arch/s390/kernel/stacktrace.c @@ -101,3 +101,22 @@ void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, } pagefault_enable(); } + +unsigned long return_address(unsigned int n) +{ + struct unwind_state state; + unsigned long addr; + + /* Increment to skip current stack entry */ + n++; + + unwind_for_each_frame(&state, NULL, NULL, 0) { + addr = unwind_get_return_address(&state); + if (!addr) + break; + if (!n--) + return addr; + } + return 0; +} +EXPORT_SYMBOL_GPL(return_address); |