X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=kernel%2Fkfifo.c;h=5d1d907378a299ad6c6aab16b15d55d1248f296e;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=179baafcdd96dccfa03a1511967012ddb99a7060;hpb=f7f1b0f1e2fbadeab12d24236000e778aa9b1ead;p=linux-2.6.git

diff --git a/kernel/kfifo.c b/kernel/kfifo.c
index 179baafcd..5d1d90737 100644
--- a/kernel/kfifo.c
+++ b/kernel/kfifo.c
@@ -36,7 +36,7 @@
  * struct kfifo with kfree().
  */
 struct kfifo *kfifo_init(unsigned char *buffer, unsigned int size,
-			 unsigned int __nocast gfp_mask, spinlock_t *lock)
+			 gfp_t gfp_mask, spinlock_t *lock)
 {
 	struct kfifo *fifo;
 
@@ -64,7 +64,7 @@ EXPORT_SYMBOL(kfifo_init);
  *
  * The size will be rounded-up to a power of 2.
  */
-struct kfifo *kfifo_alloc(unsigned int size, unsigned int __nocast gfp_mask, spinlock_t *lock)
+struct kfifo *kfifo_alloc(unsigned int size, gfp_t gfp_mask, spinlock_t *lock)
 {
 	unsigned char *buffer;
 	struct kfifo *ret;
@@ -122,6 +122,13 @@ unsigned int __kfifo_put(struct kfifo *fifo,
 
 	len = min(len, fifo->size - fifo->in + fifo->out);
 
+	/*
+	 * Ensure that we sample the fifo->out index -before- we
+	 * start putting bytes into the kfifo.
+	 */
+
+	smp_mb();
+
 	/* first put the data starting from fifo->in to buffer end */
 	l = min(len, fifo->size - (fifo->in & (fifo->size - 1)));
 	memcpy(fifo->buffer + (fifo->in & (fifo->size - 1)), buffer, l);
@@ -129,6 +136,13 @@ unsigned int __kfifo_put(struct kfifo *fifo,
 	/* then put the rest (if any) at the beginning of the buffer */
 	memcpy(fifo->buffer, buffer + l, len - l);
 
+	/*
+	 * Ensure that we add the bytes to the kfifo -before-
+	 * we update the fifo->in index.
+	 */
+
+	smp_wmb();
+
 	fifo->in += len;
 
 	return len;
@@ -154,6 +168,13 @@ unsigned int __kfifo_get(struct kfifo *fifo,
 
 	len = min(len, fifo->in - fifo->out);
 
+	/*
+	 * Ensure that we sample the fifo->in index -before- we
+	 * start removing bytes from the kfifo.
+	 */
+
+	smp_rmb();
+
 	/* first get the data from fifo->out until the end of the buffer */
 	l = min(len, fifo->size - (fifo->out & (fifo->size - 1)));
 	memcpy(buffer, fifo->buffer + (fifo->out & (fifo->size - 1)), l);
@@ -161,6 +182,13 @@ unsigned int __kfifo_get(struct kfifo *fifo,
 	/* then get the rest (if any) from the beginning of the buffer */
 	memcpy(buffer + l, fifo->buffer, len - l);
 
+	/*
+	 * Ensure that we remove the bytes from the kfifo -before-
+	 * we update the fifo->out index.
+	 */
+
+	smp_mb();
+
 	fifo->out += len;
 
 	return len;