Merge tag 'trace-3.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing cleanups and bugfixes from Steven Rostedt:
"One bug fix that goes back to 3.10. Accessing a non existent buffer
if "possible cpus" is greater than actual CPUs (including offline
CPUs).
Namhyung Kim did some reviews of the patches I sent this merge window
and found a memory leak and had a few clean ups"
* tag 'trace-3.16-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix check of ftrace_trace_arrays list_empty() check
tracing: Fix leak of per cpu max data in instances
tracing: Cleanup saved_cmdlines_size changes
ring-buffer: Check if buffer exists before polling
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h
index d69cf63..49a4d6f 100644
--- a/include/linux/ring_buffer.h
+++ b/include/linux/ring_buffer.h
@@ -97,7 +97,7 @@
__ring_buffer_alloc((size), (flags), &__key); \
})
-void ring_buffer_wait(struct ring_buffer *buffer, int cpu);
+int ring_buffer_wait(struct ring_buffer *buffer, int cpu);
int ring_buffer_poll_wait(struct ring_buffer *buffer, int cpu,
struct file *filp, poll_table *poll_table);
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index c634868..7c56c3d 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -543,7 +543,7 @@
* as data is added to any of the @buffer's cpu buffers. Otherwise
* it will wait for data to be added to a specific cpu buffer.
*/
-void ring_buffer_wait(struct ring_buffer *buffer, int cpu)
+int ring_buffer_wait(struct ring_buffer *buffer, int cpu)
{
struct ring_buffer_per_cpu *cpu_buffer;
DEFINE_WAIT(wait);
@@ -557,6 +557,8 @@
if (cpu == RING_BUFFER_ALL_CPUS)
work = &buffer->irq_work;
else {
+ if (!cpumask_test_cpu(cpu, buffer->cpumask))
+ return -ENODEV;
cpu_buffer = buffer->buffers[cpu];
work = &cpu_buffer->irq_work;
}
@@ -591,6 +593,7 @@
schedule();
finish_wait(&work->waiters, &wait);
+ return 0;
}
/**
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 16f7038..384ede3 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1085,13 +1085,13 @@
}
#endif /* CONFIG_TRACER_MAX_TRACE */
-static void wait_on_pipe(struct trace_iterator *iter)
+static int wait_on_pipe(struct trace_iterator *iter)
{
/* Iterators are static, they should be filled or empty */
if (trace_buffer_iter(iter, iter->cpu_file))
- return;
+ return 0;
- ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file);
+ return ring_buffer_wait(iter->trace_buffer->buffer, iter->cpu_file);
}
#ifdef CONFIG_FTRACE_STARTUP_TEST
@@ -1338,7 +1338,7 @@
{
int ret;
- savedcmd = kmalloc(sizeof(struct saved_cmdlines_buffer), GFP_KERNEL);
+ savedcmd = kmalloc(sizeof(*savedcmd), GFP_KERNEL);
if (!savedcmd)
return -ENOMEM;
@@ -3840,7 +3840,7 @@
int r;
arch_spin_lock(&trace_cmdline_lock);
- r = sprintf(buf, "%u\n", savedcmd->cmdline_num);
+ r = scnprintf(buf, sizeof(buf), "%u\n", savedcmd->cmdline_num);
arch_spin_unlock(&trace_cmdline_lock);
return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
@@ -3857,7 +3857,7 @@
{
struct saved_cmdlines_buffer *s, *savedcmd_temp;
- s = kmalloc(sizeof(struct saved_cmdlines_buffer), GFP_KERNEL);
+ s = kmalloc(sizeof(*s), GFP_KERNEL);
if (!s)
return -ENOMEM;
@@ -4378,6 +4378,7 @@
static int tracing_wait_pipe(struct file *filp)
{
struct trace_iterator *iter = filp->private_data;
+ int ret;
while (trace_empty(iter)) {
@@ -4399,10 +4400,13 @@
mutex_unlock(&iter->mutex);
- wait_on_pipe(iter);
+ ret = wait_on_pipe(iter);
mutex_lock(&iter->mutex);
+ if (ret)
+ return ret;
+
if (signal_pending(current))
return -EINTR;
}
@@ -5327,8 +5331,12 @@
goto out_unlock;
}
mutex_unlock(&trace_types_lock);
- wait_on_pipe(iter);
+ ret = wait_on_pipe(iter);
mutex_lock(&trace_types_lock);
+ if (ret) {
+ size = ret;
+ goto out_unlock;
+ }
if (signal_pending(current)) {
size = -EINTR;
goto out_unlock;
@@ -5538,8 +5546,10 @@
goto out;
}
mutex_unlock(&trace_types_lock);
- wait_on_pipe(iter);
+ ret = wait_on_pipe(iter);
mutex_lock(&trace_types_lock);
+ if (ret)
+ goto out;
if (signal_pending(current)) {
ret = -EINTR;
goto out;
@@ -6232,22 +6242,25 @@
return 0;
}
+static void free_trace_buffer(struct trace_buffer *buf)
+{
+ if (buf->buffer) {
+ ring_buffer_free(buf->buffer);
+ buf->buffer = NULL;
+ free_percpu(buf->data);
+ buf->data = NULL;
+ }
+}
+
static void free_trace_buffers(struct trace_array *tr)
{
if (!tr)
return;
- if (tr->trace_buffer.buffer) {
- ring_buffer_free(tr->trace_buffer.buffer);
- tr->trace_buffer.buffer = NULL;
- free_percpu(tr->trace_buffer.data);
- }
+ free_trace_buffer(&tr->trace_buffer);
#ifdef CONFIG_TRACER_MAX_TRACE
- if (tr->max_buffer.buffer) {
- ring_buffer_free(tr->max_buffer.buffer);
- tr->max_buffer.buffer = NULL;
- }
+ free_trace_buffer(&tr->max_buffer);
#endif
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 9e82551..9258f5a 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -252,7 +252,7 @@
{
struct trace_array *tr;
- if (list_empty(ftrace_trace_arrays.prev))
+ if (list_empty(&ftrace_trace_arrays))
return NULL;
tr = list_entry(ftrace_trace_arrays.prev,