Messages in this thread | | | Date | Thu, 24 Nov 2022 01:01:52 +0900 | From | Masami Hiramatsu (Google) <> | Subject | Re: [PATCH] tracing/eprobe: Update cond flag before enabling trigger |
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On Fri, 18 Nov 2022 11:19:40 -0500 Steven Rostedt <rostedt@goodmis.org> wrote:
> 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.
Maybe we need better error message so that user can notice which character caused the error.
> > > converting '-' into '_'? > > Actually, it's just the system name that's an issue. I tested this patch > and it appears to work.
Ah, the system name is more flexible than the event name because it has TRACE_SYSTEM_VAR.
Steve, can you send me the below patch?
BTW, TRACE_DEFINE_ENUM() and TRACE_DEFINE_SIZEOF() macros are using TRACE_SYSTEM instead of TRACE_SYSTEM_VAR. Should those use TRACE_SYSTEM_VAR for defining a variable?
Thank you,
> > -- 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; > }
-- Masami Hiramatsu (Google) <mhiramat@kernel.org>
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