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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-15 21:08:57 (GMT) |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-05-15 21:08:57 (GMT) |
commit | c240a539df4e2d50f86e2f31813ff6b7334cd493 (patch) | |
tree | 3a2f654b33fcfc9ee5a9c881e85f70c97f858336 | |
parent | ae3b29e67ca361f0876dad6be2061699de95d126 (diff) | |
parent | b62fdd97fcae17e483b005bafd13fadbd9840672 (diff) | |
download | linux-c240a539df4e2d50f86e2f31813ff6b7334cd493.tar.xz |
Merge tag 'trace-fixes-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"This includes a fix to a memory leak when adding filters to traces.
Also, Masami Hiramatsu fixed up some minor bugs that were discovered
by sparse."
* tag 'trace-fixes-v3.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/kprobes: Make print_*probe_event static
tracing/kprobes: Fix a sparse warning for incorrect type in assignment
tracing/kprobes: Use rcu_dereference_raw for tp->files
tracing: Fix leaks of filter preds
-rw-r--r-- | kernel/trace/trace_events_filter.c | 4 | ||||
-rw-r--r-- | kernel/trace/trace_kprobe.c | 53 |
2 files changed, 44 insertions, 13 deletions
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index a636117..e1b653f 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -750,7 +750,11 @@ static int filter_set_pred(struct event_filter *filter, static void __free_preds(struct event_filter *filter) { + int i; + if (filter->preds) { + for (i = 0; i < filter->n_preds; i++) + kfree(filter->preds[i].ops); kfree(filter->preds); filter->preds = NULL; } diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 636d45f..9f46e98 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -35,7 +35,7 @@ struct trace_probe { const char *symbol; /* symbol name */ struct ftrace_event_class class; struct ftrace_event_call call; - struct ftrace_event_file **files; + struct ftrace_event_file * __rcu *files; ssize_t size; /* trace entry size */ unsigned int nr_args; struct probe_arg args[]; @@ -185,9 +185,14 @@ static struct trace_probe *find_trace_probe(const char *event, static int trace_probe_nr_files(struct trace_probe *tp) { - struct ftrace_event_file **file = tp->files; + struct ftrace_event_file **file; int ret = 0; + /* + * Since all tp->files updater is protected by probe_enable_lock, + * we don't need to lock an rcu_read_lock. + */ + file = rcu_dereference_raw(tp->files); if (file) while (*(file++)) ret++; @@ -209,9 +214,10 @@ enable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file) mutex_lock(&probe_enable_lock); if (file) { - struct ftrace_event_file **new, **old = tp->files; + struct ftrace_event_file **new, **old; int n = trace_probe_nr_files(tp); + old = rcu_dereference_raw(tp->files); /* 1 is for new one and 1 is for stopper */ new = kzalloc((n + 2) * sizeof(struct ftrace_event_file *), GFP_KERNEL); @@ -251,11 +257,17 @@ enable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file) static int trace_probe_file_index(struct trace_probe *tp, struct ftrace_event_file *file) { + struct ftrace_event_file **files; int i; - if (tp->files) { - for (i = 0; tp->files[i]; i++) - if (tp->files[i] == file) + /* + * Since all tp->files updater is protected by probe_enable_lock, + * we don't need to lock an rcu_read_lock. + */ + files = rcu_dereference_raw(tp->files); + if (files) { + for (i = 0; files[i]; i++) + if (files[i] == file) return i; } @@ -274,10 +286,11 @@ disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file) mutex_lock(&probe_enable_lock); if (file) { - struct ftrace_event_file **new, **old = tp->files; + struct ftrace_event_file **new, **old; int n = trace_probe_nr_files(tp); int i, j; + old = rcu_dereference_raw(tp->files); if (n == 0 || trace_probe_file_index(tp, file) < 0) { ret = -EINVAL; goto out_unlock; @@ -872,9 +885,16 @@ __kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs, static __kprobes void kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs) { - struct ftrace_event_file **file = tp->files; + /* + * Note: preempt is already disabled around the kprobe handler. + * However, we still need an smp_read_barrier_depends() corresponding + * to smp_wmb() in rcu_assign_pointer() to access the pointer. + */ + struct ftrace_event_file **file = rcu_dereference_raw(tp->files); + + if (unlikely(!file)) + return; - /* Note: preempt is already disabled around the kprobe handler */ while (*file) { __kprobe_trace_func(tp, regs, *file); file++; @@ -925,9 +945,16 @@ static __kprobes void kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri, struct pt_regs *regs) { - struct ftrace_event_file **file = tp->files; + /* + * Note: preempt is already disabled around the kprobe handler. + * However, we still need an smp_read_barrier_depends() corresponding + * to smp_wmb() in rcu_assign_pointer() to access the pointer. + */ + struct ftrace_event_file **file = rcu_dereference_raw(tp->files); + + if (unlikely(!file)) + return; - /* Note: preempt is already disabled around the kprobe handler */ while (*file) { __kretprobe_trace_func(tp, ri, regs, *file); file++; @@ -935,7 +962,7 @@ kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri, } /* Event entry printers */ -enum print_line_t +static enum print_line_t print_kprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) { @@ -971,7 +998,7 @@ partial: return TRACE_TYPE_PARTIAL_LINE; } -enum print_line_t +static enum print_line_t print_kretprobe_event(struct trace_iterator *iter, int flags, struct trace_event *event) { |