Messages in this thread | | | Subject | Re: [PATCH v2] tools lib traceevent: add checks for returned EVENT_ERROR type | From | Dean Nelson <> | Date | Thu, 20 Aug 2015 10:23:25 -0500 |
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On 08/10/2015 07:22 AM, Dean Nelson wrote: > Running the following perf-stat command on an arm64 system produces the > following result... > > [root@aarch64 ~]# perf stat -e kmem:mm_page_alloc -a sleep 1 > Warning: [kmem:mm_page_alloc] function sizeof not defined > Warning: Error: expected type 4 but read 0 > Segmentation fault > [root@aarch64 ~]# > > The second warning message and SIGSEGV stem from the issue expressed in the > first warning message, and are the result of ignoring the EVENT_ERROR type > returned back through the call chain. > > Dealing with the first warning message is beyond the scope of this patch. But > the second warning is addressed by this patch's first hunk. And the SIGSEGV is > eliminated by its second hunk. > > Signed-off-by: Dean Nelson <dnelson@redhat.com> > --- > Changes in v2: > - Moved the second hunk's check for EVENT_ERROR to a separate line.
I misunderstood what Namhyung meant by his request that I put the check on separate lines.
I've posted a v3 that hopefully corrects this misunderstanding. So consider v2 NAK'd.
> tools/lib/traceevent/event-parse.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > > diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c > index cc25f05..dafddc6 100644 > --- a/tools/lib/traceevent/event-parse.c > +++ b/tools/lib/traceevent/event-parse.c > @@ -1680,6 +1680,9 @@ process_cond(struct event_format *event, struct print_arg *top, char **tok) > type = process_arg(event, left, &token); > > again: > + if (type == EVENT_ERROR) > + goto out_free; > + > /* Handle other operations in the arguments */ > if (type == EVENT_OP && strcmp(token, ":") != 0) { > type = process_op(event, left, &token); > @@ -1940,7 +1943,8 @@ process_op(struct event_format *event, struct print_arg *arg, char **tok) > > type = process_arg_token(event, right, tok, type); > > - if (right->type == PRINT_OP && > + if (type != EVENT_ERROR && > + right->type == PRINT_OP && > get_op_prio(arg->op.op) < get_op_prio(right->op.op)) { > struct print_arg tmp; > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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