summaryrefslogtreecommitdiffstats
path: root/arch/um/drivers/line.h
diff options
context:
space:
mode:
authorAl Viro <viro@zeniv.linux.org.uk>2011-09-09 17:36:37 -0400
committerRichard Weinberger <richard@nod.at>2012-03-25 00:29:53 +0100
commitd8c215adbf3901aa7d00a0f17f08d77be689f838 (patch)
tree88f7f49abb5944725f3b60d8f28a41580e7f915f /arch/um/drivers/line.h
parent43574c1afea4f798592c03cf4d4ecea4fd0a8416 (diff)
um: convert count_lock to mutex, fix a race in line_open()
If two processes are opening the same line, the second to get into line_open() will decide that it doesn't need to do anything (correctly) or wait for anything. The latter, unfortunately, is incorrect - the first opener might not be through yet. We need to have exclusion covering the entire line_init(), including the blocking parts. Moreover, the next patch will need to widen the exclusion on mconsole side of things, also including the blocking bits, so let's just convert that sucker to mutex... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um/drivers/line.h')
-rw-r--r--arch/um/drivers/line.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/um/drivers/line.h b/arch/um/drivers/line.h
index 0c4dadf5e03..471f477b271 100644
--- a/arch/um/drivers/line.h
+++ b/arch/um/drivers/line.h
@@ -32,7 +32,7 @@ struct line_driver {
struct line {
struct tty_struct *tty;
- spinlock_t count_lock;
+ struct mutex count_lock;
unsigned long count;
int valid;