aboutsummaryrefslogtreecommitdiff
path: root/kernel
diff options
context:
space:
mode:
authorSteven Rostedt (Red Hat) <rostedt@goodmis.org>2013-05-23 14:21:36 -0400
committerSteven Rostedt <rostedt@rostedt.homelinux.com>2013-05-28 10:53:20 -0400
commit6721cb60022629ae76365551f05d9658b8d14c55 (patch)
tree00d16ebb628161995b02939460d3f7b8d0f5ac53 /kernel
parentca1643186d3dce6171d8f171e516b02496360a9e (diff)
downloadlinux-6721cb60022629ae76365551f05d9658b8d14c55.tar.gz
ring-buffer: Do not poll non allocated cpu buffers
The tracing infrastructure sets up for possible CPUs, but it uses the ring buffer polling, it is possible to call the ring buffer polling code with a CPU that hasn't been allocated. This will cause a kernel oops when it access a ring buffer cpu buffer that is part of the possible cpus but hasn't been allocated yet as the CPU has never been online. Reported-by: Mauro Carvalho Chehab <mchehab@redhat.com> Tested-by: Mauro Carvalho Chehab <mchehab@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/trace/ring_buffer.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c
index b59aea2c48c..e444ff88f0a 100644
--- a/kernel/trace/ring_buffer.c
+++ b/kernel/trace/ring_buffer.c
@@ -620,6 +620,9 @@ int ring_buffer_poll_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 -EINVAL;
+
cpu_buffer = buffer->buffers[cpu];
work = &cpu_buffer->irq_work;
}