tracing: user local buffer variable for trace branch tracer

Just using the tr->buffer for the API to trace_buffer_lock_reserve
is not good enough. This is because the tr->buffer may change, and we
do not want to commit with a different buffer that we reserved from.

This patch uses a local variable to hold the buffer that was used to
reserve and commit with.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt 2009-10-07 21:53:41 -04:00 committed by Steven Rostedt
parent c8647b2872
commit 8f6e8a314a

View file

@ -34,6 +34,7 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
struct trace_array *tr = branch_tracer;
struct ring_buffer_event *event;
struct trace_branch *entry;
struct ring_buffer *buffer;
unsigned long flags;
int cpu, pc;
const char *p;
@ -54,7 +55,8 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
goto out;
pc = preempt_count();
event = trace_buffer_lock_reserve(tr->buffer, TRACE_BRANCH,
buffer = tr->buffer;
event = trace_buffer_lock_reserve(buffer, TRACE_BRANCH,
sizeof(*entry), flags, pc);
if (!event)
goto out;
@ -74,8 +76,8 @@ probe_likely_condition(struct ftrace_branch_data *f, int val, int expect)
entry->line = f->line;
entry->correct = val == expect;
if (!filter_check_discard(call, entry, tr->buffer, event))
ring_buffer_unlock_commit(tr->buffer, event);
if (!filter_check_discard(call, entry, buffer, event))
ring_buffer_unlock_commit(buffer, event);
out:
atomic_dec(&tr->data[cpu]->disabled);