Messages in this thread Patch in this message | | | From | Serban Constantinescu <> | Subject | [PATCH v6 4/6] staging: android: binder: fix alignment issues | Date | Thu, 4 Jul 2013 10:54:46 +0100 |
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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.constantinescu@arm.com> Acked-by: Arve Hjønnevåg <arve@android.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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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