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.
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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
This commit is contained in:
Linus Torvalds 2014-06-12 21:07:25 -07:00
Родитель b7c8c1945c da9c3413a2
Коммит 8841c8b3c4
4 изменённых файлов: 37 добавлений и 21 удалений

Просмотреть файл

@ -97,7 +97,7 @@ __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *k
__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);

Просмотреть файл

@ -543,7 +543,7 @@ static void rb_wake_up_waiters(struct irq_work *work)
* 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 @@ void ring_buffer_wait(struct ring_buffer *buffer, int cpu)
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 @@ void ring_buffer_wait(struct ring_buffer *buffer, int cpu)
schedule();
finish_wait(&work->waiters, &wait);
return 0;
}
/**

Просмотреть файл

@ -1085,13 +1085,13 @@ update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu)
}
#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 @@ static int trace_create_savedcmd(void)
{
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 @@ tracing_saved_cmdlines_size_read(struct file *filp, char __user *ubuf,
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 @@ static int tracing_resize_saved_cmdlines(unsigned int val)
{
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 @@ tracing_poll_pipe(struct file *filp, poll_table *poll_table)
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 @@ static int tracing_wait_pipe(struct file *filp)
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 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
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 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
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 @@ static int allocate_trace_buffers(struct trace_array *tr, int size)
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
}

Просмотреть файл

@ -252,7 +252,7 @@ static inline struct trace_array *top_trace_array(void)
{
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,