diff options
| author | Ingo Molnar <mingo@elte.hu> | 2010-11-18 08:07:36 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2010-11-18 08:07:36 +0100 |
| commit | a89d4bd055718d3b4ddb380ee22951a1300b4096 (patch) | |
| tree | ca7a040a619f7c1fb6a42e77be7ff9147417aa2b /kernel | |
| parent | e53beacd23d9cb47590da6a7a7f6d417b941a994 (diff) | |
| parent | 91e86e560d0b3ce4c5fc64fd2bbb99f856a30a4e (diff) | |
Merge branch 'tip/perf/urgent-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-2.6-trace into perf/urgent
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/module.c | 12 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 19 |
2 files changed, 31 insertions, 0 deletions
diff --git a/kernel/module.c b/kernel/module.c index 437a74a7524a..d190664f25ff 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2326,6 +2326,18 @@ static void find_module_sections(struct module *mod, struct load_info *info) kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) * mod->num_trace_events, GFP_KERNEL); #endif +#ifdef CONFIG_TRACING + mod->trace_bprintk_fmt_start = section_objs(info, "__trace_printk_fmt", + sizeof(*mod->trace_bprintk_fmt_start), + &mod->num_trace_bprintk_fmt); + /* + * This section contains pointers to allocated objects in the trace + * code and not scanning it leads to false positives. + */ + kmemleak_scan_area(mod->trace_bprintk_fmt_start, + sizeof(*mod->trace_bprintk_fmt_start) * + mod->num_trace_bprintk_fmt, GFP_KERNEL); +#endif #ifdef CONFIG_FTRACE_MCOUNT_RECORD /* sechdrs[0].sh_size is always zero */ mod->ftrace_callsites = section_objs(info, "__mcount_loc", diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 82d9b8106cd0..ee6a7339cf0e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1284,6 +1284,8 @@ void trace_dump_stack(void) __ftrace_trace_stack(global_trace.buffer, flags, 3, preempt_count()); } +static DEFINE_PER_CPU(int, user_stack_count); + void ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) { @@ -1302,6 +1304,18 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) if (unlikely(in_nmi())) return; + /* + * prevent recursion, since the user stack tracing may + * trigger other kernel events. + */ + preempt_disable(); + if (__this_cpu_read(user_stack_count)) + goto out; + + __this_cpu_inc(user_stack_count); + + + event = trace_buffer_lock_reserve(buffer, TRACE_USER_STACK, sizeof(*entry), flags, pc); if (!event) @@ -1319,6 +1333,11 @@ ftrace_trace_userstack(struct ring_buffer *buffer, unsigned long flags, int pc) save_stack_trace_user(&trace); if (!filter_check_discard(call, entry, buffer, event)) ring_buffer_unlock_commit(buffer, event); + + __this_cpu_dec(user_stack_count); + + out: + preempt_enable(); } #ifdef UNUSED |