The patch titled
dma_alloc_from_coherent(): fix fallback to generic memory
has been removed from the -mm tree. Its filename was
dma_alloc_from_coherent-fix-fallback-to-generic-memory.patch
This patch was dropped because it was merged into mainline or a subsystem tree
The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/
------------------------------------------------------
Subject: dma_alloc_from_coherent(): fix fallback to generic memory
From: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
If bitmap_find_free_region() fails and DMA_MEMORY_EXCLUSIVE is not set,
the function will fail to write anything to *ret and will return 1. This will cause dma_alloc_coherent() to return an uninitialised value,
crashing the kernel, perhaps via DMA to a random address.
Fix that by changing it to return zero in this case, so the caller will
proceed to allocate the memory from the generic memory allocator.
Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
Cc: Dmitry Baryshkov <dbaryshkov@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
kernel/dma-coherent.c | 16 +++++++++++++++-
1 file changed, 15 insertions(+), 1 deletion(-)
diff -puN kernel/dma-coherent.c~dma_alloc_from_coherent-fix-fallback-to-generic-memory kernel/dma-coherent.c
--- a/kernel/dma-coherent.c~dma_alloc_from_coherent-fix-fallback-to-generic-memory
+++ a/kernel/dma-coherent.c
@@ -116,11 +116,25 @@ int dma_alloc_from_coherent(struct devic
int page = bitmap_find_free_region(mem->bitmap, mem->size,
order);
if (page >= 0) {
+ /*
+ * Memory was found in the per-device arena.
+ */
*dma_handle = mem->device_base + (page << PAGE_SHIFT);
*ret = mem->virt_base + (page << PAGE_SHIFT);
memset(*ret, 0, size);
- } else if (mem->flags & DMA_MEMORY_EXCLUSIVE)
+ } else if (mem->flags & DMA_MEMORY_EXCLUSIVE) {
+ /*
+ * The per-device arena is exhausted and we are not
+ * permitted to fall back to generic memory.
+ */
*ret = NULL;
+ } else {
+ /*
+ * The per-device arena is exhausted and we are
+ * permitted to fall back to generic memory.
+ */
+ return 0;
+ }
}
return (mem != NULL);
}
_
Patches currently in -mm which might be from akpm@xxxxxxxxxxxxxxxxxxxx are
origin.patch
i-need-old-gcc.patch
mm-remove-the-might_sleep-from-lock_page.patch
linux-next.patch
next-remove-localversion.patch
linux-next-git-rejects.patch
clocksource-pass-clocksource-to-read-callback-sparc-cleanup.patch
drivers-input-touchscreen-ucb1400_tsc-needs-gpio.patch
video-mbp_nvidia_bl-add-support-for-macbook-5-macbook-air-2-and-macbook-pro-5-fix.patch
pci-quirks-unhide-overflow-device-on-i828675p-pe-chipsets.patch
raw-fix-rawctl-compat-ioctls-breakage-on-amd64-and-itanic-checkpatch-fixes.patch
scsi-dpt_i2o-is-bust-on-ia64.patch
page_fault-retry-with-nopage_retry-fix.patch
page_fault-retry-with-nopage_retry-fix-fix.patch
mm-add-proc-controls-for-pdflush-threads-fix.patch
mm-add-proc-controls-for-pdflush-threads-fix-fix.patch
smp_call_function_single-be-slightly-less-stupid.patch
cgroups-skip-processes-from-other-namespaces-when-listing-a-cgroup-checkpatch-fixes.patch
memcg-introduce-charge-commit-cancel-style-of-functions-fix.patch
memcg-new-force_empty-to-free-pages-under-group-fix-fix.patch
memcg-swap-cgroup-for-remembering-usage.patch
memory-cgroup-resource-counters-for-hierarchy-v4-checkpatch-fixes.patch
memory-cgroup-hierarchical-reclaim-v4-checkpatch-fixes.patch
memcg-avoid-unnecessary-system-wide-oom-killer-fix.patch
w1-allow-master-io-commands-fix.patch
romfs-romfs_iget-unsigned-ino-=-0-is-always-true-checkpatch-fixes.patch
filesystem-freeze-implement-generic-freeze-feature-fix.patch
nilfs2-inode-operations-fix.patch
nilfs2-pathname-operations-fix.patch
nilfs2-super-block-operations-fix.patch
kmemleak-add-the-base-support-fix.patch
reiser4.patch
reiser4-remove-simple_prepare_write-usage-checkpatch-fixes.patch
nr_blockdev_pages-in_interrupt-warning.patch
slab-leaks3-default-y.patch
put_bh-debug.patch
shrink_slab-handle-bad-shrinkers.patch
getblk-handle-2tb-devices.patch
getblk-handle-2tb-devices-fix.patch
undeprecate-pci_find_device.patch
notify_change-callers-must-hold-i_mutex.patch
drivers-net-bonding-bond_sysfsc-suppress-uninitialized-var-warning.patch
w1-build-fix.patch
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