diff options
| author | Steven Rostedt <srostedt@redhat.com> | 2009-02-13 20:53:42 -0500 |
|---|---|---|
| committer | Steven Rostedt <srostedt@redhat.com> | 2009-02-16 17:03:49 -0500 |
| commit | e68746a271eb3393a2183840be9e903caddf765b (patch) | |
| tree | 106ea87792837ccee1476687d9f9a067f96488a9 | |
| parent | 64e7c440618998fd69eee6ab490b042d12248021 (diff) | |
ftrace: enable filtering only when a function is filtered on
Impact: fix to prevent empty set_ftrace_filter and no ftrace output
The function filter is used to only trace a given set of functions.
The filter is enabled when a function name is echoed into the
set_ftrace_filter file. But if the name has a typo and the function
is not found, the filter is enabled, but no function is listed.
This makes a confusing situation where set_ftrace_filter is empty
but no functions ever get enabled for tracing.
For example:
# cat /debug/tracing/set_ftrace_filter
#### all functions enabled ####
# echo bad_name > set_ftrace_filter
# cat /debug/tracing/set_ftrace_filter
# echo function > current_tracer
# cat trace
# tracer: nop
#
# TASK-PID CPU# TIMESTAMP FUNCTION
# | | | | |
This patch changes that to only enable filtering if a function
is set to be filtered on. Now, the filter is not enabled if
a bad name is echoed into set_ftrace_filter.
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
| -rw-r--r-- | kernel/trace/ftrace.c | 14 |
1 files changed, 8 insertions, 6 deletions
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 9e60ae423af..340f88b68d9 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1153,8 +1153,6 @@ static void ftrace_match_records(char *buff, int len, int enable) /* should not be called from interrupt context */ spin_lock(&ftrace_lock); - if (enable) - ftrace_filtered = 1; do_for_each_ftrace_rec(pg, rec) { if (rec->flags & FTRACE_FL_FAILED) @@ -1166,7 +1164,12 @@ static void ftrace_match_records(char *buff, int len, int enable) else rec->flags |= flag; } - + /* + * Only enable filtering if we have a function that + * is filtered on. + */ + if (enable && (rec->flags & FTRACE_FL_FILTER)) + ftrace_filtered = 1; } while_for_each_ftrace_rec(); spin_unlock(&ftrace_lock); } @@ -1217,9 +1220,6 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable) /* should not be called from interrupt context */ spin_lock(&ftrace_lock); - if (enable) - ftrace_filtered = 1; - do_for_each_ftrace_rec(pg, rec) { if (rec->flags & FTRACE_FL_FAILED) @@ -1232,6 +1232,8 @@ static void ftrace_match_module_records(char *buff, char *mod, int enable) else rec->flags |= flag; } + if (enable && (rec->flags & FTRACE_FL_FILTER)) + ftrace_filtered = 1; } while_for_each_ftrace_rec(); spin_unlock(&ftrace_lock); |