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| author |   Heiko Carstens <heiko.carstens@de.ibm.com> | 2014-11-24 14:30:32 +0100 |
|---|---|---|
| committer |   Martin Schwidefsky <schwidefsky@de.ibm.com> | 2014-11-28 09:47:15 +0100 |
| commit | 7eed2e09abf0a0064a7e3f4a911b37d71202dfa4 (patch) | |
| tree | 8c33fd1d185503919d2ed06e6372ae3f5aeec257 /arch/s390/include/asm/ftrace.h | |
| parent | s390/sclp_async: add Kconfig option to specify the component id (diff) | |
| download | linux-dev-7eed2e09abf0a0064a7e3f4a911b37d71202dfa4.tar.xz linux-dev-7eed2e09abf0a0064a7e3f4a911b37d71202dfa4.zip | |
s390/ftrace: provide working ftrace_return_address()
The common code ftrace_return_address(n), which is just a wrapper for
__builtin_return_address(n), will only work for n > 0 if CONFIG_FRAME_POINTER
is set to 'y'. Otherwise it will return 0.
Since on s390 we will never have that config option set to 'y'
ftrace_return_address() won't work at all for n > 0.
Luckily we always compile the kernel with -mkernel-backchain which
in turn means that __builtin_return_address(n) will always work.
So let ftrace_return_address(n) map to __builtin_return_address(n).
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/include/asm/ftrace.h')
| -rw-r--r-- | arch/s390/include/asm/ftrace.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/s390/include/asm/ftrace.h b/arch/s390/include/asm/ftrace.h index 785041f1dc77..abb618f1ead2 100644 --- a/arch/s390/include/asm/ftrace.h +++ b/arch/s390/include/asm/ftrace.h @@ -8,6 +8,8 @@ #ifndef __ASSEMBLY__ +#define ftrace_return_address(n) __builtin_return_address(n) + void _mcount(void); void ftrace_caller(void); |