From: "Steven Rostedt (VMware)" rostedt@goodmis.org

Al Viro reported:

For substring - sure, but what about something like "*a*b" and "a*b"? AFAICS, filter_parse_regex() ends up with identical results in both cases - MATCH_GLOB and *search = "a*b". And no way for the caller to tell one from another.

Testing this with the following:

# cd /sys/kernel/tracing # echo '*raw*lock' > set_ftrace_filter bash: echo: write error: Invalid argument

With this patch:

# echo '*raw*lock' > set_ftrace_filter # cat set_ftrace_filter _raw_read_trylock _raw_write_trylock _raw_read_unlock _raw_spin_unlock _raw_write_unlock _raw_spin_trylock _raw_spin_lock _raw_write_lock _raw_read_lock

Al recommended not setting the search buffer to skip the first '*' unless we know we are not using MATCH_GLOB. This implements his suggested logic.

Link: http://lkml.kernel.org/r/20180127170748.GF13338@ZenIV.linux.org.uk

Cc: stable@vger.kernel.org Fixes: 60f1d5e3bac44 ("ftrace: Support full glob matching") Reviewed-by: Masami Hiramatsu mhiramat@kernel.org Reported-by: Al Viro viro@ZenIV.linux.org.uk Suggsted-by: Al Viro viro@ZenIV.linux.org.uk Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org --- kernel/trace/trace_events_filter.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 61e7f0678d33..a764aec3c9a1 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -400,7 +400,6 @@ enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not) for (i = 0; i < len; i++) { if (buff[i] == '*') { if (!i) { - *search = buff + 1; type = MATCH_END_ONLY; } else if (i == len - 1) { if (type == MATCH_END_ONLY) @@ -410,14 +409,14 @@ enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not) buff[i] = 0; break; } else { /* pattern continues, use full glob */ - type = MATCH_GLOB; - break; + return MATCH_GLOB; } } else if (strchr("[?\", buff[i])) { - type = MATCH_GLOB; - break; + return MATCH_GLOB; } } + if (buff[0] == '*') + *search = buff + 1;

return type; }