lkml.org 
[lkml]   [2010]   [Jul]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH] trace-cmd: Don't SIGSEGV when event field format cannot be parsed.
    From
    Date
    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@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);




    \
     
     \ /
      Last update: 2010-07-22 22:11    [W:0.021 / U:125.084 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site