diff options
| author | Ingo Molnar <mingo@kernel.org> | 2013-09-03 07:41:11 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2013-09-03 07:41:11 +0200 |
| commit | 7d992feb7694a21ee81f22894b455dadd5d1c110 (patch) | |
| tree | d0f0961186b1c31c536a26a7f986ad7ca677453b /kernel/trace | |
| parent | 6e4664525b1db28f8c4e1130957f70a94c19213e (diff) | |
| parent | 25f27ce4a6a4995c8bdd69b4b2180465ed5ad2b8 (diff) | |
Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:
"
* Update RCU documentation. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/611.
* Miscellaneous fixes. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/619.
* Full-system idle detection. This is for use by Frederic
Weisbecker's adaptive-ticks mechanism. Its purpose is
to allow the timekeeping CPU to shut off its tick when
all other CPUs are idle. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/648.
* Improve rcutorture test coverage. These were posted to LKML at
https://lkml.org/lkml/2013/8/19/675.
"
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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 afaae41b0a0..fe39acd4c1a 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1022,6 +1022,9 @@ extern struct list_head ftrace_events; extern const char *__start___trace_bprintk_fmt[]; extern const char *__stop___trace_bprintk_fmt[]; +extern const char *__start___tracepoint_str[]; +extern const char *__stop___tracepoint_str[]; + void trace_printk_init_buffers(void); void trace_printk_start_comm(void); 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 a9077c1b4ad..2900817ba65 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) { const char **fmt = v; int start_index; + int last_index; start_index = __stop___trace_bprintk_fmt - __start___trace_bprintk_fmt; if (*pos < start_index) return __start___trace_bprintk_fmt + *pos; + /* + * The __tracepoint_str section is treated the same as the + * __trace_printk_fmt section. The difference is that the + * __trace_printk_fmt section should only be used by trace_printk() + * in a debugging environment, as if anything exists in that section + * the trace_prink() helper buffers are allocated, which would just + * waste space in a production environment. + * + * The __tracepoint_str sections on the other hand are used by + * tracepoints which need to map pointers to their strings to + * the ASCII text for userspace. + */ + last_index = start_index; + start_index = __stop___tracepoint_str - __start___tracepoint_str; + + if (*pos < last_index + start_index) + return __start___tracepoint_str + (*pos - last_index); + return find_next_mod_format(start_index, v, fmt, pos); } |