[PATCH][RFC] Always unlock 'tasklist_lock' inkernel/exit.c::do_wait()

From: Jesper Juhl
Date: Mon Dec 20 2010 - 17:39:34 EST


Hi,

The Coverity checker spotted this. I think it has a point, but I'm not
intimate with this code so there could be somethingI'm missing.

It seems that kernel/exit.c::do_wait() does not always release
'tasklist_lock'. There are multiple ways the code could be changed to make
sure it's always released, I just picked the most straight forward one.

Does this look right to everyone else or is it just me?
I've only compile tested the patch so far.


Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
---
exit.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/exit.c b/kernel/exit.c
index 676149a..456b13d 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1647,12 +1647,16 @@ repeat:
tsk = current;
do {
retval = do_wait_thread(wo, tsk);
- if (retval)
+ if (retval) {
+ read_unlock(&tasklist_lock);
goto end;
+ }

retval = ptrace_do_wait(wo, tsk);
- if (retval)
+ if (retval) {
+ read_unlock(&tasklist_lock);
goto end;
+ }

if (wo->wo_flags & __WNOTHREAD)
break;



--
Jesper Juhl <jj@xxxxxxxxxxxxx> http://www.chaosbits.net/
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
Plain text mails only, please.

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