diff options
| author |   Adrian Hunter <adrian.hunter@intel.com> | 2020-05-12 15:19:13 +0300 |
|---|---|---|
| committer |   Peter Zijlstra <peterz@infradead.org> | 2020-06-15 14:09:49 +0200 |
| commit | fc0ea795f53c8d7040fa42471f74fe51d78d0834 (patch) | |
| tree | ddf3830f325d6540366e8ef1cc934b7ccb7d081c /include/linux/ftrace.h | |
| parent | perf/x86: Add perf text poke events for kprobes (diff) | |
| download | linux-dev-fc0ea795f53c8d7040fa42471f74fe51d78d0834.tar.xz linux-dev-fc0ea795f53c8d7040fa42471f74fe51d78d0834.zip | |
ftrace: Add symbols for ftrace trampolines
Symbols are needed for tools to describe instruction addresses. Pages
allocated for ftrace's purposes need symbols to be created for them.
Add such symbols to be visible via /proc/kallsyms.
Example on x86 with CONFIG_DYNAMIC_FTRACE=y
# echo function > /sys/kernel/debug/tracing/current_tracer
# cat /proc/kallsyms | grep '\[__builtin__ftrace\]'
ffffffffc0238000 t ftrace_trampoline [__builtin__ftrace]
Note: This patch adds "__builtin__ftrace" as a module name in /proc/kallsyms for
symbols for pages allocated for ftrace's purposes, even though "__builtin__ftrace"
is not a module.
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200512121922.8997-7-adrian.hunter@intel.com
Diffstat (limited to 'include/linux/ftrace.h')
| -rw-r--r-- | include/linux/ftrace.h | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index e339dac91ee6..ce2c06f72e86 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -58,9 +58,6 @@ struct ftrace_direct_func; const char * ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, unsigned long *off, char **modname, char *sym); -int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, - char *type, char *name, - char *module_name, int *exported); #else static inline const char * ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, @@ -68,6 +65,13 @@ ftrace_mod_address_lookup(unsigned long addr, unsigned long *size, { return NULL; } +#endif + +#if defined(CONFIG_FUNCTION_TRACER) && defined(CONFIG_DYNAMIC_FTRACE) +int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, + char *type, char *name, + char *module_name, int *exported); +#else static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *value, char *type, char *name, char *module_name, int *exported) @@ -76,7 +80,6 @@ static inline int ftrace_mod_get_kallsym(unsigned int symnum, unsigned long *val } #endif - #ifdef CONFIG_FUNCTION_TRACER extern int ftrace_enabled; @@ -207,6 +210,7 @@ struct ftrace_ops { struct ftrace_ops_hash old_hash; unsigned long trampoline; unsigned long trampoline_size; + struct list_head list; #endif }; |