Messages in this thread | | | Subject | Re: [PATCH 5/9] perf util: Handle failure case in trace_report() | From | Steven Rostedt <> | Date | Tue, 19 Mar 2013 21:54:34 -0400 |
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On Wed, 2013-03-20 at 10:12 +0900, Namhyung Kim wrote:
> >> +++ b/tools/perf/util/trace-event-read.c > >> @@ -293,7 +293,10 @@ ssize_t trace_report(int fd, struct pevent **ppevent, bool __repipe) > >> int show_version = 0; > >> int show_funcs = 0; > >> int show_printk = 0; > >> - ssize_t size; > >> + ssize_t size = -1; > >> + struct pevent *pevent; > >> + > >> + *ppevent = NULL; > >> > >> calc_data_size = 1; > >> repipe = __repipe; > >> @@ -317,34 +320,38 @@ ssize_t trace_report(int fd, struct pevent **ppevent, bool __repipe) > >> file_bigendian = buf[0]; > >> host_bigendian = bigendian(); > >> > >> - *ppevent = read_trace_init(file_bigendian, host_bigendian); > >> - if (*ppevent == NULL) > >> - die("read_trace_init failed"); > >> + pevent = read_trace_init(file_bigendian, host_bigendian); > >> + if (pevent == NULL) { > > > > Shouldn't we still set *ppevent to NULL? Or will the user now need to > > make sure that its pevent is NULL and always check for error? > > I thought it's impossible to check return value for error since we don't > know how large a tracing data is, so I decided to init *ppevent to NULL > at the beginning and set it to a valid pevent right before return. Thus > user need to check NULL before using it. > > In the above case of perf_event__process_tracing_data(), it's a pipe > mode and we can know its size since it's saved in a temp file. >
My fault, I missed the addition of *ppevent = NULL at the beginning. Ignore this comment.
-- Steve
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