ion: fix overflow and list bugs in system heap

Fix a few bugs in ion_system_heap:

Initialize the list node in the info block.

Don't store size_remaining in a signed long, allocating >2GB
could overflow, resulting in a call to sg_alloc_table with
nents=0 which panics.  alloc_largest_available will never
return a block larger than size_remanining, so it can never
go negative.

Limit a single allocation to half of all memory.  Prevents a
large allocation from taking down the whole system.

Change-Id: I7fcbd7e1d5b4d482d7612d80b6c9e8e24466f1d8
Signed-off-by: Colin Cross <ccross@android.com>
This commit is contained in:
Colin Cross
2013-12-19 18:37:49 -08:00
committed by Mitchel Humpherys
parent 14f162cb64
commit c69de844c8

View File

@@ -124,6 +124,7 @@ static struct page_info *alloc_largest_available(struct ion_system_heap *heap,
info->page = page;
info->order = orders[i];
INIT_LIST_HEAD(&info->list);
return info;
}
kfree(info);
@@ -145,12 +146,15 @@ static int ion_system_heap_allocate(struct ion_heap *heap,
struct list_head pages;
struct page_info *info, *tmp_info;
int i = 0;
long size_remaining = PAGE_ALIGN(size);
unsigned long size_remaining = PAGE_ALIGN(size);
unsigned int max_order = orders[0];
if (align > PAGE_SIZE)
return -EINVAL;
if (size / PAGE_SIZE > totalram_pages / 2)
return -ENOMEM;
INIT_LIST_HEAD(&pages);
while (size_remaining > 0) {
info = alloc_largest_available(sys_heap, buffer, size_remaining,