Normal free:212600kB min:7664kB low:57100kB high:106536kB
reserved_highatomic:4096KB active_anon:276kB inactive_anon:180kB
active_file:1200kB inactive_file:0kB unevictable:2932kB
writepending:0kB present:4109312kB managed:3689488kB mlocked:2932kB
pagetables:13600kB bounce:0kB free_pcp:0kB local_pcp:0kB
free_cma:200844kB
Out of memory and no killable processes...
Kernel panic - not syncing: System is deadlocked on memory
An OoM panic was reported. The log shows there were only native
processes which are non-killable as OOM_SCORE_ADJ_MIN. After looking
into the dump, I've found the dma-buf system heap was trying to allocate
a huge size. It seems to be a signed negative value.
dma_heap_ioctl_allocate(inline)
| heap_allocation = 0xFFFFFFC02247BD38 -> (
| len = 0xFFFFFFFFE7225100,
To avoid this invalid request, check if the requested size is bigger
than system total memory. Actually the old ion system heap had similar
policy with commit c9e8440eca61 ("staging: ion: Fix overflow and list
bugs in system heap").
Even with this sanity check, there is still risk of too much allocations
from the system_heap. Allocating multiple big size buffers may cause
oom. Add __GFP_RETRY_MAYFAIL. With this gfp, the allocation may fail,
but we can avoid oom panic.
Signed-off-by: Jaewon Kim <jaewon31.kim@xxxxxxxxxxx>
Acked-by: John Stultz <jstultz@xxxxxxxxxx>
Reviewed-by: T.J. Mercier <tjmercier@xxxxxxxxxx>
---
drivers/dma-buf/heaps/system_heap.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c
index 920db302a273..583da8948679 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -41,7 +41,7 @@ struct dma_heap_attachment {
bool mapped;
};
-#define LOW_ORDER_GFP (GFP_HIGHUSER | __GFP_ZERO)
+#define LOW_ORDER_GFP (GFP_HIGHUSER | __GFP_ZERO | __GFP_RETRY_MAYFAIL)
#define HIGH_ORDER_GFP (((GFP_HIGHUSER | __GFP_ZERO | __GFP_NOWARN \
| __GFP_NORETRY) & ~__GFP_RECLAIM) \
| __GFP_COMP)
@@ -350,6 +350,9 @@ static struct dma_buf *system_heap_allocate(struct dma_heap *heap,
struct page *page, *tmp_page;
int i, ret = -ENOMEM;
+ if (len / PAGE_SIZE > totalram_pages())
+ return ERR_PTR(-ENOMEM);
+
buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
if (!buffer)
return ERR_PTR(-ENOMEM);
--
2.17.1
