The Android userspace aligns the data written to the binder buffers to
4bytes. Thus for 32bit platforms or 64bit platforms running an 32bit
Android userspace we can have a buffer looking like this:
platform buffer(binder_cmd pointer) size
32/32 32b 32b 8B
64/32 32b 64b 12B
64/64 32b 64b 12B
Thus the kernel needs to check that the buffer size is aligned to 4bytes
not to (void *) that will be 8bytes on 64bit machines.
The change does not affect existing 32bit ABI.
Signed-off-by: Serban Constantinescu <serban.constantine...@arm.com>
---
drivers/staging/android/binder.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index ce70909..7450d56 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -1247,7 +1247,7 @@ static void binder_transaction_buffer_release(struct
binder_proc *proc,
struct flat_binder_object *fp;
if (*offp > buffer->data_size - sizeof(*fp) ||
buffer->data_size < sizeof(*fp) ||
- !IS_ALIGNED(*offp, sizeof(void *))) {
+ !IS_ALIGNED(*offp, sizeof(u32))) {
pr_err("transaction release %d bad offset %zd, size
%zd\n",
debug_id, *offp, buffer->data_size);
continue;
@@ -1496,7 +1496,7 @@ static void binder_transaction(struct binder_proc *proc,
struct flat_binder_object *fp;
if (*offp > t->buffer->data_size - sizeof(*fp) ||
t->buffer->data_size < sizeof(*fp) ||
- !IS_ALIGNED(*offp, sizeof(void *))) {
+ !IS_ALIGNED(*offp, sizeof(u32))) {
binder_user_error("%d:%d got transaction with invalid
offset, %zd\n",
proc->pid, thread->pid, *offp);
return_error = BR_FAILED_REPLY;
--
1.7.9.5
--
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