diff options
Diffstat (limited to 'kernel/trace')
-rw-r--r-- | kernel/trace/trace.h | 3 | ||||
-rw-r--r-- | kernel/trace/trace_printk.c | 19 |
2 files changed, 22 insertions, 0 deletions
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index afaae41b0a02..fe39acd4c1aa 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h | |||
@@ -1022,6 +1022,9 @@ extern struct list_head ftrace_events; | |||
1022 | extern const char *__start___trace_bprintk_fmt[]; | 1022 | extern const char *__start___trace_bprintk_fmt[]; |
1023 | extern const char *__stop___trace_bprintk_fmt[]; | 1023 | extern const char *__stop___trace_bprintk_fmt[]; |
1024 | 1024 | ||
1025 | extern const char *__start___tracepoint_str[]; | ||
1026 | extern const char *__stop___tracepoint_str[]; | ||
1027 | |||
1025 | void trace_printk_init_buffers(void); | 1028 | void trace_printk_init_buffers(void); |
1026 | void trace_printk_start_comm(void); | 1029 | void trace_printk_start_comm(void); |
1027 | int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set); | 1030 | int trace_keep_overwrite(struct tracer *tracer, u32 mask, int set); |
diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index a9077c1b4ad3..2900817ba65c 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c | |||
@@ -244,12 +244,31 @@ static const char **find_next(void *v, loff_t *pos) | |||
244 | { | 244 | { |
245 | const char **fmt = v; | 245 | const char **fmt = v; |
246 | int start_index; | 246 | int start_index; |
247 | int last_index; | ||
247 | 248 | ||
248 | start_index = __stop___trace_bprintk_fmt - __start___trace_bprintk_fmt; | 249 | start_index = __stop___trace_bprintk_fmt - __start___trace_bprintk_fmt; |
249 | 250 | ||
250 | if (*pos < start_index) | 251 | if (*pos < start_index) |
251 | return __start___trace_bprintk_fmt + *pos; | 252 | return __start___trace_bprintk_fmt + *pos; |
252 | 253 | ||
254 | /* | ||
255 | * The __tracepoint_str section is treated the same as the | ||
256 | * __trace_printk_fmt section. The difference is that the | ||
257 | * __trace_printk_fmt section should only be used by trace_printk() | ||
258 | * in a debugging environment, as if anything exists in that section | ||
259 | * the trace_prink() helper buffers are allocated, which would just | ||
260 | * waste space in a production environment. | ||
261 | * | ||
262 | * The __tracepoint_str sections on the other hand are used by | ||
263 | * tracepoints which need to map pointers to their strings to | ||
264 | * the ASCII text for userspace. | ||
265 | */ | ||
266 | last_index = start_index; | ||
267 | start_index = __stop___tracepoint_str - __start___tracepoint_str; | ||
268 | |||
269 | if (*pos < last_index + start_index) | ||
270 | return __start___tracepoint_str + (*pos - last_index); | ||
271 | |||
253 | return find_next_mod_format(start_index, v, fmt, pos); | 272 | return find_next_mod_format(start_index, v, fmt, pos); |
254 | } | 273 | } |
255 | 274 | ||