From c9960e48543799f168c4c9486f9790fb686ce5a8 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 5 Mar 2013 10:53:02 -0500 Subject: [PATCH] tracing: Do not return EINVAL in snapshot when not allocated To use the tracing snapshot feature, writing a '1' into the snapshot file causes the snapshot buffer to be allocated if it has not already been allocated and dose a 'swap' with the main buffer, so that the snapshot now contains what was in the main buffer, and the main buffer now writes to what was the snapshot buffer. To free the snapshot buffer, a '0' is written into the snapshot file. To clear the snapshot buffer, any number but a '0' or '1' is written into the snapshot file. But if the file is not allocated it returns -EINVAL error code. This is rather pointless. It is better just to do nothing and return success. Acked-by: Hiraku Toyooka Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 2 -- 1 file changed, 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 9e3120b8a2ad..1f835a83cb2c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -4167,8 +4167,6 @@ tracing_snapshot_write(struct file *filp, const char __user *ubuf, size_t cnt, default: if (current_trace->allocated_snapshot) tracing_reset_online_cpus(&max_tr); - else - ret = -EINVAL; break; } -- 2.20.1