Messages in this thread | | | Date | Tue, 24 May 2022 18:34:03 -0400 | From | Steven Rostedt <> | Subject | Re: [PATCH 2/2] tracing/probes: make match function safe |
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Masami and Tom, what are you thoughts on this?
-- Steve
On Sun, May 01, 2022 at 05:34:11PM +0800, Linyu Yuan wrote: > When delete one kprobe/uprobe/eprobe event entry > using /sys/kernel/debug/tracing/dynamic_events file, > it will loop all dynamic envent entries, > as user will not input dyn_event_operations type, > when call the match function of kprobe/uprobe/eprobe, > the dynamic event may have different dyn_event_operations type, > but currently match function may return a match. > > Fix by check dyn_event_operations type first. > > Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com> > --- > kernel/trace/trace_eprobe.c | 31 +++++++++++++++++++++++-------- > kernel/trace/trace_kprobe.c | 3 +++ > kernel/trace/trace_uprobe.c | 3 +++ > 3 files changed, 29 insertions(+), 8 deletions(-) > > diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c > index b16e067..0029840 100644 > --- a/kernel/trace/trace_eprobe.c > +++ b/kernel/trace/trace_eprobe.c > @@ -19,6 +19,21 @@ > > #define EPROBE_EVENT_SYSTEM "eprobes" > > +static int eprobe_dyn_event_create(const char *raw_command); > +static int eprobe_dyn_event_show(struct seq_file *m, struct dyn_event *ev); > +static bool eprobe_dyn_event_is_busy(struct dyn_event *ev); > +static int eprobe_dyn_event_release(struct dyn_event *ev); > +static bool eprobe_dyn_event_match(const char *system, const char *event, > + int argc, const char **argv, struct dyn_event *ev); > + > +static struct dyn_event_operations eprobe_dyn_event_ops = { > + .create = eprobe_dyn_event_create, > + .show = eprobe_dyn_event_show, > + .is_busy = eprobe_dyn_event_is_busy, > + .free = eprobe_dyn_event_release, > + .match = eprobe_dyn_event_match, > +}; > + > struct trace_eprobe { > /* tracepoint system */ > const char *event_system; > @@ -39,6 +54,11 @@ struct eprobe_data { > > static int __trace_eprobe_create(int argc, const char *argv[]); > > +static bool is_trace_eprobe(struct dyn_event *ev) > +{ > + return ev->ops == &eprobe_dyn_event_ops; > +} > + > static void trace_event_probe_cleanup(struct trace_eprobe *ep) > { > if (!ep) > @@ -121,6 +141,9 @@ static bool eprobe_dyn_event_match(const char *system, const char *event, > struct trace_eprobe *ep = to_trace_eprobe(ev); > const char *slash; > > + if (!is_trace_eprobe(ev)) > + return false; > + > /* > * We match the following: > * event only - match all eprobes with event name > @@ -174,14 +197,6 @@ static bool eprobe_dyn_event_match(const char *system, const char *event, > return trace_probe_match_command_args(&ep->tp, argc, argv); > } > > -static struct dyn_event_operations eprobe_dyn_event_ops = { > - .create = eprobe_dyn_event_create, > - .show = eprobe_dyn_event_show, > - .is_busy = eprobe_dyn_event_is_busy, > - .free = eprobe_dyn_event_release, > - .match = eprobe_dyn_event_match, > -}; > - > static struct trace_eprobe *alloc_event_probe(const char *group, > const char *this_event, > struct trace_event_call *event, > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index 2cd8ef9..f63abfa 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -163,6 +163,9 @@ static bool trace_kprobe_match(const char *system, const char *event, > { > struct trace_kprobe *tk = to_trace_kprobe(ev); > > + if (!is_trace_kprobe(ev)) > + return false; > + > return (event[0] == '\0' || > strcmp(trace_probe_name(&tk->tp), event) == 0) && > (!system || strcmp(trace_probe_group_name(&tk->tp), system) == 0) && > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index a935c08..ee55ed0 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -312,6 +312,9 @@ static bool trace_uprobe_match(const char *system, const char *event, > { > struct trace_uprobe *tu = to_trace_uprobe(ev); > > + if (!is_trace_uprobe(ev)) > + return false; > + > return (event[0] == '\0' || > strcmp(trace_probe_name(&tu->tp), event) == 0) && > (!system || strcmp(trace_probe_group_name(&tu->tp), system) == 0) && > -- > 2.7.4
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