From ff078d8fc644722f7b163d79e8a03b00b9dc2385 Mon Sep 17 00:00:00 2001 From: Jerry Snitselaar Date: Mon, 16 Nov 2015 12:57:28 -0700 Subject: [PATCH] tracing: Use seq_buf_used() in seq_buf_to_user() instead of len commit 5ac48378414d ("tracing: Use trace_seq_used() and seq_buf_used() instead of len") changed the tracing code to use trace_seq_used() and seq_buf_used() instead of using the seq_buf len directly to avoid overflow issues, but missed a spot in seq_buf_to_user() that makes use of s->len. Cleaned up the code a bit as well per suggestion of Steve Rostedt. Link: http://lkml.kernel.org/r/1447703848-2951-1-git-send-email-jsnitsel@redhat.com Signed-off-by: Jerry Snitselaar Signed-off-by: Steven Rostedt --- lib/seq_buf.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/lib/seq_buf.c b/lib/seq_buf.c index 5c94e1012a91..cb18469e1f49 100644 --- a/lib/seq_buf.c +++ b/lib/seq_buf.c @@ -306,10 +306,12 @@ int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, int cnt) if (!cnt) return 0; - if (s->len <= s->readpos) + len = seq_buf_used(s); + + if (len <= s->readpos) return -EBUSY; - len = seq_buf_used(s) - s->readpos; + len -= s->readpos; if (cnt > len) cnt = len; ret = copy_to_user(ubuf, s->buffer + s->readpos, cnt);