The patch titled
slub: update cpu after new_slab()
has been removed from the -mm tree. Its filename was
slub-core-update-cpu-after-new_slab.patch
This patch was dropped because it was folded into slub-core.patch
------------------------------------------------------
Subject: slub: update cpu after new_slab()
From: Hugh Dickins <hugh@xxxxxxxxxxx>
SLUB gave me a NULL pointer dereference in slab_alloc(), in the
slab_lock(page) of its "Current cpuslab is acceptable" block: cpu 1 had
been looking at cpu_slab[2], which then went NULL beneath it. Since
new_slab() may reenable interrupts and sleep (when __GFP_WAIT), we may get
rescheduled on a different cpu: so need to reevaluate it.
Signed-off-by: Hugh Dickins <hugh@xxxxxxxxxxx>
Acked-by: Christoph Lameter <clameter@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slub.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
diff -puN mm/slub.c~slub-core-update-cpu-after-new_slab mm/slub.c
--- a/mm/slub.c~slub-core-update-cpu-after-new_slab
+++ a/mm/slub.c
@@ -1234,11 +1234,12 @@ have_slab:
page = new_slab(s, gfpflags, node);
if (page) {
+ cpu = smp_processor_id();
if (s->cpu_slab[cpu]) {
/*
- * Someone else populated the cpu_slab while
- * we enabled interrupts. The page may not
- * be on the requested node.
+ * Someone else populated the cpu_slab while we enabled
+ * interrupts, or we have got scheduled on another cpu.
+ * The page may not be on the requested node.
*/
if (node == -1 ||
page_to_nid(s->cpu_slab[cpu]) == node) {
_
Patches currently in -mm which might be from hugh@xxxxxxxxxxx are
ia64-race-flushing-icache-in-do_no_page-path.patch
git-drm.patch
scsi-fix-config_scsi_wait_scan=m.patch
i386-make-compat_vdso-runtime-selectable-fix.patch
mm-more-rmap-checking.patch
mm-make-read_cache_page-synchronous.patch
fs-buffer-dont-pageuptodate-without-page-locked.patch
add-__gfp_movable-for-callers-to-flag-allocations-from-high-memory-that-may-be-migrated.patch
i386-add-ptep_test_and_clear_dirtyyoung.patch
i386-use-pte_update_defer-in-ptep_test_and_clear_dirtyyoung.patch
smaps-extract-pmd-walker-from-smaps-code.patch
smaps-add-pages-referenced-count-to-smaps.patch
smaps-add-clear_refs-file-to-clear-reference.patch
slub-core.patch
slub-core-update-cpu-after-new_slab.patch
mm-madvise-avoid-exclusive-mmap_sem.patch
lazy-freeing-of-memory-through-madv_free.patch
lazy-freeing-of-memory-through-madv_free-fix.patch
madv_free-lazytlb-fix.patch
lazy-freeing-of-memory-through-madv_free-vs-mm-madvise-avoid-exclusive-mmap_sem.patch
restore-madv_dontneed-to-its-original-linux-behaviour.patch
tty-in-tiocsctty-when-we-steal-a-tty-hang-it-up-fix.patch
ext2-reservations.patch
ext2-balloc-use-io_error-label.patch
add-__gfp_movable-for-callers-to-flag-allocations-from-high-memory-that-may-be-migrated-swap-prefetch.patch
-
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