The patch titled
drivers/char/mmtimer.c: eliminate useless code
has been added to the -mm tree. Its filename is
drivers-char-mmtimerc-eliminate-useless-code.patch
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------------------------------------------------------
Subject: drivers/char/mmtimer.c: eliminate useless code
From: Julia Lawall <julia@xxxxxxx>
The variable x is initialized twice to the same (side effect-free)
expression. Drop one initialization.
A simplified version of the semantic match that finds this problem is:
(http://coccinelle.lip6.fr/)
// <smpl>
@forall@
idexpression *x;
identifier f!=ERR_PTR;
@@
x = f(...)
... when != x
(
x = f(...,<+...x...+>,...)
|
* x = f(...)
)
// </smpl>
Stefan observed:
The next x = rb_entry(mn->next, struct mmtimer, list); is preceded by a
test whether mn->next is NULL.
Unless that test is redundant too, your patch fixes a potential NULL
pointer dereference, introduced by commit cbacdd95 "SGI Altix mmtimer:
allow larger number of timers per node" in 2.6.26.
Signed-off-by: Julia Lawall <julia@xxxxxxx>
Cc: Stefan Richter <stefanr@xxxxxxxxxxxxxxxxx>
Cc: Dimitri Sivanich <sivanich@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/char/mmtimer.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff -puN drivers/char/mmtimer.c~drivers-char-mmtimerc-eliminate-useless-code drivers/char/mmtimer.c
--- a/drivers/char/mmtimer.c~drivers-char-mmtimerc-eliminate-useless-code
+++ a/drivers/char/mmtimer.c
@@ -546,7 +546,7 @@ static void mmtimer_tasklet(unsigned lon
{
int nodeid = data;
struct mmtimer_node *mn = &timers[nodeid];
- struct mmtimer *x = rb_entry(mn->next, struct mmtimer, list);
+ struct mmtimer *x;
struct k_itimer *t;
unsigned long flags;
_
Patches currently in -mm which might be from julia@xxxxxxx are
linux-next.patch
drivers-scsi-sesc-eliminate-double-free.patch
kernel-credc-use-kmem_cache_free.patch
arch-arm-plat-pxa-dmac-correct-null-test.patch
drivers-gpu-drm-nouveau-nouveau_grctxc-correct-null-test.patch
drivers-media-video-move-dereference-after-null-test.patch
net-ipv4-correct-the-size-argument-to-kzalloc.patch
drivers-scsi-libsas-use-sam_good.patch
drivers-scsi-remove-unnecessary-null-test.patch
drivers-message-move-dereference-after-null-test.patch
drivers-scsi-correct-the-size-argument-to-kmalloc.patch
drivers-staging-tm6000-tm6000-videoc-correct-null-test.patch
drivers-edac-introduce-missing-kfree.patch
drivers-char-mmtimerc-eliminate-useless-code.patch
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