| Message ID | 20230128-list-entry-null-check-v1-1-8bde6a3da2ef@diag.uniroma1.it (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 81d0fa4cb4fc0e1a49c2b22f92c43d9fe972ebcf |
| Delegated to: | Masami Hiramatsu |
| Headers | show |
| Series | tracing/probe: trace_probe_primary_from_call(): checked list_first_entry | expand |
On Sat, 28 Jan 2023 16:23:41 +0000 Pietro Borrello <borrello@diag.uniroma1.it> wrote: > All callers of trace_probe_primary_from_call() check the return > value to be non NULL. However, the function returns > list_first_entry(&tpe->probes, ...) which can never be NULL. > Additionally, it does not check for the list being possibly empty, > possibly causing a type confusion on empty lists. > Use list_first_entry_or_null() which solves both problems. > > Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") > Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it> > --- > kernel/trace/trace_probe.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h > index 23acfd1c3812..f6b565dced56 100644 > --- a/kernel/trace/trace_probe.h > +++ b/kernel/trace/trace_probe.h > @@ -307,7 +307,7 @@ trace_probe_primary_from_call(struct trace_event_call *call) > { > struct trace_probe_event *tpe = trace_probe_event_from_call(call); > > - return list_first_entry(&tpe->probes, struct trace_probe, list); > + return list_first_entry_or_null(&tpe->probes, struct trace_probe, list); > } > > static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp) Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> -- Steve > > --- > base-commit: 2241ab53cbb5cdb08a6b2d4688feb13971058f65 > change-id: 20230128-list-entry-null-check-37778efda18c > > Best regards,
On Sat, 28 Jan 2023 16:23:41 +0000 Pietro Borrello <borrello@diag.uniroma1.it> wrote: > All callers of trace_probe_primary_from_call() check the return > value to be non NULL. However, the function returns > list_first_entry(&tpe->probes, ...) which can never be NULL. > Additionally, it does not check for the list being possibly empty, > possibly causing a type confusion on empty lists. > Use list_first_entry_or_null() which solves both problems. > > Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") > Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it> Looks good to me. Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> And Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") Cc: stable@vger.kernel.org Thank you! > --- > kernel/trace/trace_probe.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h > index 23acfd1c3812..f6b565dced56 100644 > --- a/kernel/trace/trace_probe.h > +++ b/kernel/trace/trace_probe.h > @@ -307,7 +307,7 @@ trace_probe_primary_from_call(struct trace_event_call *call) > { > struct trace_probe_event *tpe = trace_probe_event_from_call(call); > > - return list_first_entry(&tpe->probes, struct trace_probe, list); > + return list_first_entry_or_null(&tpe->probes, struct trace_probe, list); > } > > static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp) > > --- > base-commit: 2241ab53cbb5cdb08a6b2d4688feb13971058f65 > change-id: 20230128-list-entry-null-check-37778efda18c > > Best regards, > -- > Pietro Borrello <borrello@diag.uniroma1.it>
>All callers of trace_probe_primary_from_call() check the return >value to be non NULL. However, the function returns >list_first_entry(&tpe->probes, ...) which can never be NULL. >Additionally, it does not check for the list being possibly empty, >possibly causing a type confusion on empty lists. >Use list_first_entry_or_null() which solves both problems. > >Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") >Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it> >--- > kernel/trace/trace_probe.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > >diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h >index 23acfd1c3812..f6b565dced56 100644 >--- a/kernel/trace/trace_probe.h >+++ b/kernel/trace/trace_probe.h >@@ -307,7 +307,7 @@ trace_probe_primary_from_call(struct trace_event_call *call) > { > struct trace_probe_event *tpe = trace_probe_event_from_call(call); > >- return list_first_entry(&tpe->probes, struct trace_probe, list); >+ return list_first_entry_or_null(&tpe->probes, struct trace_probe, list); > } Nice catch !! Acked-by: Mukesh Ojha <quic_mojha@quicinc.com> -Mukesh > > static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 23acfd1c3812..f6b565dced56 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -307,7 +307,7 @@ trace_probe_primary_from_call(struct trace_event_call *call) { struct trace_probe_event *tpe = trace_probe_event_from_call(call); - return list_first_entry(&tpe->probes, struct trace_probe, list); + return list_first_entry_or_null(&tpe->probes, struct trace_probe, list); } static inline struct list_head *trace_probe_probe_list(struct trace_probe *tp)
All callers of trace_probe_primary_from_call() check the return value to be non NULL. However, the function returns list_first_entry(&tpe->probes, ...) which can never be NULL. Additionally, it does not check for the list being possibly empty, possibly causing a type confusion on empty lists. Use list_first_entry_or_null() which solves both problems. Fixes: 60d53e2c3b75 ("tracing/probe: Split trace_event related data from trace_probe") Signed-off-by: Pietro Borrello <borrello@diag.uniroma1.it> --- kernel/trace/trace_probe.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- base-commit: 2241ab53cbb5cdb08a6b2d4688feb13971058f65 change-id: 20230128-list-entry-null-check-37778efda18c Best regards,