From 794e43b56c18b95fc9776c914a2659e7d558a352 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Wed, 5 May 2010 00:27:40 -0500 Subject: [PATCH] perf/live-mode: Handle payload-less events Some events, such as the PERF_RECORD_FINISHED_ROUND event consist of only an event header and no data. In this case, a 0-length payload will be read, and the 0 return value will be wrongly interpreted as an 'unexpected end of event stream'. This patch allows for proper handling of data-less events by skipping 0-length reads. Signed-off-by: Tom Zanussi Cc: Arnaldo Carvalho de Melo Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Masami Hiramatsu LKML-Reference: <1273038527.6383.51.camel@tropicana> Signed-off-by: Frederic Weisbecker --- tools/perf/util/session.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-) diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c index 9401909fa28..00ab298bbb4 100644 --- a/tools/perf/util/session.c +++ b/tools/perf/util/session.c @@ -696,15 +696,18 @@ more: p = &event; p += sizeof(struct perf_event_header); - err = do_read(self->fd, p, size - sizeof(struct perf_event_header)); - if (err <= 0) { - if (err == 0) { - pr_err("unexpected end of event stream\n"); - goto done; - } + if (size - sizeof(struct perf_event_header)) { + err = do_read(self->fd, p, + size - sizeof(struct perf_event_header)); + if (err <= 0) { + if (err == 0) { + pr_err("unexpected end of event stream\n"); + goto done; + } - pr_err("failed to read event data\n"); - goto out_err; + pr_err("failed to read event data\n"); + goto out_err; + } } if (size == 0 || -- 2.41.0