diff options
author | Namhyung Kim <namhyung.kim@lge.com> | 2014-01-03 14:12:46 +0900 |
---|---|---|
committer | Steven Rostedt <rostedt@goodmis.org> | 2014-01-03 15:27:18 -0500 |
commit | e0d18fe063464cb3f1a6d1939e4fcf47d92d8386 (patch) | |
tree | 061fdc3f78de07af82fbe7695c3c5e78d896c3bd | |
parent | b7e0bf341f6cfa92ae0a0e3d0c3496729595e1e9 (diff) | |
download | linux-stable-e0d18fe063464cb3f1a6d1939e4fcf47d92d8386.tar.gz linux-stable-e0d18fe063464cb3f1a6d1939e4fcf47d92d8386.tar.bz2 linux-stable-e0d18fe063464cb3f1a6d1939e4fcf47d92d8386.zip |
tracing/probes: Fix build break on !CONFIG_KPROBE_EVENT
When kprobe-based dynamic event tracer is not enabled, it caused
following build error:
kernel/built-in.o: In function `traceprobe_update_arg':
(.text+0x10c8dd): undefined reference to `fetch_symbol_u8'
kernel/built-in.o: In function `traceprobe_update_arg':
(.text+0x10c8e9): undefined reference to `fetch_symbol_u16'
kernel/built-in.o: In function `traceprobe_update_arg':
(.text+0x10c8f5): undefined reference to `fetch_symbol_u32'
kernel/built-in.o: In function `traceprobe_update_arg':
(.text+0x10c901): undefined reference to `fetch_symbol_u64'
kernel/built-in.o: In function `traceprobe_update_arg':
(.text+0x10c909): undefined reference to `fetch_symbol_string'
kernel/built-in.o: In function `traceprobe_update_arg':
(.text+0x10c913): undefined reference to `fetch_symbol_string_size'
...
It was due to the fetch methods are referred from CHECK_FETCH_FUNCS
macro and since it was only defined in trace_kprobe.c. Move NULL
definition of such fetch functions to the header file.
Note, it also requires CONFIG_BRANCH_PROFILING enabled to trigger
this failure as well. This is because the "fetch_symbol_*" variables
are referenced in a "else if" statement that will only call
update_symbol_cache(), which is a static inline stub function
when CONFIG_KPROBE_EVENT is not enabled. gcc is smart enough
to optimize this "else if" out and that also removes the code that
references the undefined variables.
But when BRANCH_PROFILING is enabled, it fools gcc into keeping
the if statement around and thus references the undefined symbols
and fails to build.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r-- | kernel/trace/trace_probe.h | 8 | ||||
-rw-r--r-- | kernel/trace/trace_uprobe.c | 8 |
2 files changed, 8 insertions, 8 deletions
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index e29d743fef5d..b73574a5f429 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -243,6 +243,14 @@ unsigned long update_symbol_cache(struct symbol_cache *sc); void free_symbol_cache(struct symbol_cache *sc); struct symbol_cache *alloc_symbol_cache(const char *sym, long offset); #else +/* uprobes do not support symbol fetch methods */ +#define fetch_symbol_u8 NULL +#define fetch_symbol_u16 NULL +#define fetch_symbol_u32 NULL +#define fetch_symbol_u64 NULL +#define fetch_symbol_string NULL +#define fetch_symbol_string_size NULL + struct symbol_cache { }; static inline unsigned long __used update_symbol_cache(struct symbol_cache *sc) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 1fdea6d3f851..79e52d93860b 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -172,14 +172,6 @@ static __kprobes void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs, *(u32 *)dest = len; } -/* uprobes do not support symbol fetch methods */ -#define fetch_symbol_u8 NULL -#define fetch_symbol_u16 NULL -#define fetch_symbol_u32 NULL -#define fetch_symbol_u64 NULL -#define fetch_symbol_string NULL -#define fetch_symbol_string_size NULL - static unsigned long translate_user_vaddr(void *file_offset) { unsigned long base_addr; |