From: Serban Constantinescu <serban.constantinescu@arm.com>
Date: Wed, 4 Dec 2013 18:09:37 +0000 (+0000)
Subject: staging: android: binder: Add deref_helper() macro
X-Git-Tag: firefly_0821_release~3680^2~4^2~33^2~5
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=98e77a8deabe744d3754f28f54e435d72407b8a9;p=firefly-linux-kernel-4.4.55.git

staging: android: binder: Add deref_helper() macro

This patch adds a deref_helper() macro that will be used to dereference
the binder offsets on 64bit systems where the offset is either a 32bit
or a 64bit value, depending on the userpace used (32bit /64bit)

This patch is a temporary patch that will be extended with 32bit compat
handling.

Signed-off-by: Serban Constantinescu <serban.constantinescu@arm.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
---

diff --git a/drivers/staging/android/binder.c b/drivers/staging/android/binder.c
index 8a4e252ece9e..38d47f1fee37 100644
--- a/drivers/staging/android/binder.c
+++ b/drivers/staging/android/binder.c
@@ -142,6 +142,7 @@ module_param_call(stop_on_user_error, binder_set_stop_on_user_error,
 	} while (0)
 
 #define align_helper(ptr)	    ALIGN(ptr, sizeof(void *))
+#define deref_helper(ptr)	    (*(typeof(size_t *))ptr)
 
 enum binder_stat_types {
 	BINDER_STAT_PROC,
@@ -1231,7 +1232,7 @@ static void binder_transaction_buffer_release(struct binder_proc *proc,
 					      struct binder_buffer *buffer,
 					      size_t *failed_at)
 {
-	size_t *offp, *off_end;
+	void *offp, *off_end;
 	int debug_id = buffer->debug_id;
 
 	binder_debug(BINDER_DEBUG_TRANSACTION,
@@ -1247,16 +1248,16 @@ static void binder_transaction_buffer_release(struct binder_proc *proc,
 		off_end = failed_at;
 	else
 		off_end = (void *)offp + buffer->offsets_size;
-	for (; offp < off_end; offp++) {
+	for (; offp < off_end; offp += sizeof(size_t)) {
 		struct flat_binder_object *fp;
-		if (*offp > buffer->data_size - sizeof(*fp) ||
+		if (deref_helper(offp) > buffer->data_size - sizeof(*fp) ||
 		    buffer->data_size < sizeof(*fp) ||
-		    !IS_ALIGNED(*offp, sizeof(u32))) {
+		    !IS_ALIGNED(deref_helper(offp), sizeof(u32))) {
 			pr_err("transaction release %d bad offset %zd, size %zd\n",
-			 debug_id, *offp, buffer->data_size);
+			 debug_id, deref_helper(offp), buffer->data_size);
 			continue;
 		}
-		fp = (struct flat_binder_object *)(buffer->data + *offp);
+		fp = (struct flat_binder_object *)(buffer->data + deref_helper(offp));
 		switch (fp->type) {
 		case BINDER_TYPE_BINDER:
 		case BINDER_TYPE_WEAK_BINDER: {
@@ -1306,7 +1307,7 @@ static void binder_transaction(struct binder_proc *proc,
 {
 	struct binder_transaction *t;
 	struct binder_work *tcomplete;
-	size_t *offp, *off_end;
+	void *offp, *off_end;
 	struct binder_proc *target_proc;
 	struct binder_thread *target_thread = NULL;
 	struct binder_node *target_node = NULL;
@@ -1500,17 +1501,17 @@ static void binder_transaction(struct binder_proc *proc,
 		goto err_bad_offset;
 	}
 	off_end = (void *)offp + tr->offsets_size;
-	for (; offp < off_end; offp++) {
+	for (; offp < off_end; offp += sizeof(size_t)) {
 		struct flat_binder_object *fp;
-		if (*offp > t->buffer->data_size - sizeof(*fp) ||
+		if (deref_helper(offp) > t->buffer->data_size - sizeof(*fp) ||
 		    t->buffer->data_size < sizeof(*fp) ||
-		    !IS_ALIGNED(*offp, sizeof(u32))) {
+		    !IS_ALIGNED(deref_helper(offp), sizeof(u32))) {
 			binder_user_error("%d:%d got transaction with invalid offset, %zd\n",
-					proc->pid, thread->pid, *offp);
+					proc->pid, thread->pid, deref_helper(offp));
 			return_error = BR_FAILED_REPLY;
 			goto err_bad_offset;
 		}
-		fp = (struct flat_binder_object *)(t->buffer->data + *offp);
+		fp = (struct flat_binder_object *)(t->buffer->data + deref_helper(offp));
 		switch (fp->type) {
 		case BINDER_TYPE_BINDER:
 		case BINDER_TYPE_WEAK_BINDER: {