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authorSteven Rostedt <srostedt@redhat.com>2012-03-27 10:43:28 -0400
committerSteven Rostedt <rostedt@goodmis.org>2012-03-27 12:05:44 -0400
commit12b5da349a8b94c9dbc3430a6bc42eabd9eaf50b (patch)
treea785d2b0757cacc15cd02e9eb6da3210c79a8aea
parent2c86bf172e550b4bf089ac7f0de3f6370e243842 (diff)
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tracing: Fix ent_size in trace output
When reading the trace file, the records of each of the per_cpu buffers are examined to find the next event to print out. At the point of looking at the event, the size of the event is recorded. But if the first event is chosen, the other events in the other CPU buffers will reset the event size that is stored in the iterator descriptor, causing the event size passed to the output functions to be incorrect. In most cases this is not a problem, but for the case of stack traces, it is. With the change to the stack tracing to record a dynamic number of back traces, the output depends on the size of the entry instead of the fixed 8 back traces. When the entry size is not correct, the back traces would not be fully printed. Note, reading from the per-cpu trace files were not affected. Reported-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Thomas Gleixner <tglx@linutronix.de> Cc: stable@vger.kernel.org Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
-rw-r--r--kernel/trace/trace.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 3a19c354edd6..ed7b5d1e12f4 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1698,6 +1698,7 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu,
int cpu_file = iter->cpu_file;
u64 next_ts = 0, ts;
int next_cpu = -1;
+ int next_size = 0;
int cpu;
/*
@@ -1729,9 +1730,12 @@ __find_next_entry(struct trace_iterator *iter, int *ent_cpu,
next_cpu = cpu;
next_ts = ts;
next_lost = lost_events;
+ next_size = iter->ent_size;
}
}
+ iter->ent_size = next_size;
+
if (ent_cpu)
*ent_cpu = next_cpu;