Messages in this thread Patch in this message | | | Date | Fri, 18 Nov 2022 11:19:40 -0500 | From | Steven Rostedt <> | Subject | Re: [PATCH] tracing/eprobe: Update cond flag before enabling trigger |
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On Fri, 18 Nov 2022 10:34:40 -0300 Rafael Mendonca <rafaelmendsr@gmail.com> wrote:
> It did not trigger the NULL pointer issue to be more specific. When > creating event probe for all events I was unable to create any event for > the xhci-hcd system: > > root@localhost:/sys/kernel/tracing# echo 'e xhci-hcd/xhci_add_endpoint' > dynamic_events > -bash: echo: write error: Invalid argument > > Debugging the issue it seems that the problem is in the is_good_name() > check, which returns false for "xhci-hcd". Should we sanitize it by
Ouch. I didn't realize that.
> converting '-' into '_'?
Actually, it's just the system name that's an issue. I tested this patch and it appears to work.
-- Steve
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 54ee5711c729..a16fb4c9642e 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1955,17 +1955,30 @@ static __always_inline void trace_iterator_reset(struct trace_iterator *iter) } /* Check the name is good for event/group/fields */ -static inline bool is_good_name(const char *name) +static inline bool __is_good_name(const char *name, bool hash_ok) { - if (!isalpha(*name) && *name != '_') + if (!isalpha(*name) && *name != '_' && (!hash_ok || *name != '-')) return false; while (*++name != '\0') { - if (!isalpha(*name) && !isdigit(*name) && *name != '_') + if (!isalpha(*name) && !isdigit(*name) && *name != '_' && + (!hash_ok || *name != '-')) return false; } return true; } +/* Check the name is good for event/group/fields */ +static inline bool is_good_name(const char *name) +{ + return __is_good_name(name, false); +} + +/* Check the name is good for system */ +static inline bool is_good_system_name(const char *name) +{ + return __is_good_name(name, true); +} + /* Convert certain expected symbols into '_' when generating event names */ static inline void sanitize_event_name(char *name) { diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index 36dff277de46..bb2f95d7175c 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -246,7 +246,7 @@ int traceprobe_parse_event_name(const char **pevent, const char **pgroup, return -EINVAL; } strlcpy(buf, event, slash - event + 1); - if (!is_good_name(buf)) { + if (!is_good_system_name(buf)) { trace_probe_log_err(offset, BAD_GROUP_NAME); return -EINVAL; }
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