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| author | Josef Bacik <josef@toxicpanda.com> | 2020-07-24 20:50:48 -0400 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2020-08-03 16:12:31 -0400 |
| commit | c58b6b0372de0d4cd0536d6585addd1b36b151ae (patch) | |
| tree | 7a34498988bfaea770137aabf44a3328a3a930da /kernel | |
| parent | 1c39d761ff5c90227fc582c45018d5922efaa253 (diff) | |
| download | linux-c58b6b0372de0d4cd0536d6585addd1b36b151ae.tar.gz | |
ftrace: Fix ftrace_trace_task return value
I was attempting to use pid filtering with function_graph, but it wasn't
allowing anything to make it through. Turns out ftrace_trace_task
returns false if ftrace_ignore_pid is not-empty, which isn't correct
anymore. We're now setting it to FTRACE_PID_IGNORE if we need to ignore
that pid, otherwise it's set to the pid (which is weird considering the
name) or to FTRACE_PID_TRACE. Fix the check to check for !=
FTRACE_PID_IGNORE. With this we can now use function_graph with pid
filtering.
Link: https://lkml.kernel.org/r/20200725005048.1790-1-josef@toxicpanda.com
Fixes: 717e3f5ebc82 ("ftrace: Make function trace pid filtering a bit more exact")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/ftrace.c | 3 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 7 |
2 files changed, 6 insertions, 4 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f433cb44300a..4e3a5d79c078 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -139,9 +139,6 @@ static inline void ftrace_ops_init(struct ftrace_ops *ops) #endif } -#define FTRACE_PID_IGNORE -1 -#define FTRACE_PID_TRACE -2 - static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, struct pt_regs *regs) { diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f21607f87189..610d21355526 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1103,6 +1103,10 @@ print_graph_function_flags(struct trace_iterator *iter, u32 flags) extern struct list_head ftrace_pids; #ifdef CONFIG_FUNCTION_TRACER + +#define FTRACE_PID_IGNORE -1 +#define FTRACE_PID_TRACE -2 + struct ftrace_func_command { struct list_head list; char *name; @@ -1114,7 +1118,8 @@ struct ftrace_func_command { extern bool ftrace_filter_param __initdata; static inline int ftrace_trace_task(struct trace_array *tr) { - return !this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid); + return this_cpu_read(tr->array_buffer.data->ftrace_ignore_pid) != + FTRACE_PID_IGNORE; } extern int ftrace_is_dead(void); int ftrace_create_function_files(struct trace_array *tr, |