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 Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ 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 -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html