lkml.org 
[lkml]   [2013]   [Apr]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2 6/7] staging: android: binder: fix alignment issues
Date
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>
---
drivers/staging/android/binder.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index a2cdd9e..b5c2b59 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -658,8 +658,8 @@ static struct binder_buffer *binder_alloc_buf(struct binder_proc *proc,
return NULL;
}

- size = ALIGN(data_size, sizeof(void *)) +
- ALIGN(offsets_size, sizeof(void *));
+ size = ALIGN(data_size, sizeof(u32)) +
+ ALIGN(offsets_size, sizeof(u32));

if (size < data_size || size < offsets_size) {
binder_user_error("%d: got transaction with invalid size %zd-%zd\n",
@@ -807,8 +807,8 @@ static void binder_free_buf(struct binder_proc *proc,

buffer_size = binder_buffer_size(proc, buffer);

- size = ALIGN(buffer->data_size, sizeof(void *)) +
- ALIGN(buffer->offsets_size, sizeof(void *));
+ size = ALIGN(buffer->data_size, sizeof(u32)) +
+ ALIGN(buffer->offsets_size, sizeof(u32));

binder_debug(BINDER_DEBUG_BUFFER_ALLOC,
"%d: binder_free_buf %p size %zd buffer_size %zd\n",
@@ -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


\
 
 \ /
  Last update: 2013-04-09 12:41    [W:0.106 / U:0.832 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site