trace-cmd: Don't SIGSEGV when event field format cannot be parsed.
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From: Steven Rostedt on 22 Jul 2010 16:10 On Tue, 2010-07-13 at 11:44 -0700, David Daney wrote: > >From the MIPS kernel we get things like: > > print fmt: "page=%p pfn=%lu order=%d migratetype=%d", REC->page, ({ struct page *__pg = (REC->page); int __sec = page_to_section(__pg); (unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec))); }), REC->order, REC->migratetype > > This cannot be parsed, leading to a NULL struct event_format* being > passed to pevent_get_common_field_val, which produces a SIGSEGV. It > would be good to get a parsable format from the kernel, but to > remediate the problem for legacy kernels, we can just return an error > indicator in this case. This allows some output from trace-cmd > report, although perhaps with some missing data. But this is better > than crashing. > > Signed-off-by: David Daney <ddaney(a)caviumnetworks.com> > --- > parse-events.c | 3 +++ > 1 files changed, 3 insertions(+), 0 deletions(-) > > diff --git a/parse-events.c b/parse-events.c > index 9d5a3fa..16fff12 100644 > --- a/parse-events.c > +++ b/parse-events.c > @@ -4481,6 +4481,9 @@ int pevent_get_common_field_val(struct trace_seq *s, struct event_format *event, > { To be consistent, probably all the pevent_get_*field* should test for null event. Did you want to resend a patch that does that? -- Steve > struct format_field *field; > > + if (!event) > + return -1; > + > field = pevent_find_common_field(event, name); > > return get_field_val(s, field, name, record, val, err); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |