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authorDan Carpenter <dan.carpenter@oracle.com>2022-08-04 10:11:33 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-08-25 12:18:26 +0300
commit2f14656fe1a8998b781a0bf20911170f61873b65 (patch)
tree0e9b881c6fc16e2ff1db4d4ed40d972bc0188ca8
parentc61d3b92f56a784b0e59e0542c06ddb8f3e16f71 (diff)
downloadlinux-2f14656fe1a8998b781a0bf20911170f61873b65.tar.xz
xen/xenbus: fix return type in xenbus_file_read()
commit 32ad11127b95236dfc52375f3707853194a7f4b4 upstream. This code tries to store -EFAULT in an unsigned int. The xenbus_file_read() function returns type ssize_t so the negative value is returned as a positive value to the user. This change forces another change to the min() macro. Originally, the min() macro used "unsigned" type which checkpatch complains about. Also unsigned type would break if "len" were not capped at MAX_RW_COUNT. Use size_t for the min(). (No effect on runtime for the min_t() change). Fixes: 2fb3683e7b16 ("xen: Add xenbus device driver") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Link: https://lore.kernel.org/r/YutxJUaUYRG/VLVc@kili Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/xen/xenbus/xenbus_dev_frontend.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/xen/xenbus/xenbus_dev_frontend.c b/drivers/xen/xenbus/xenbus_dev_frontend.c
index 597af455a522..0792fda49a15 100644
--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -128,7 +128,7 @@ static ssize_t xenbus_file_read(struct file *filp,
{
struct xenbus_file_priv *u = filp->private_data;
struct read_buffer *rb;
- unsigned i;
+ ssize_t i;
int ret;
mutex_lock(&u->reply_mutex);
@@ -148,7 +148,7 @@ again:
rb = list_entry(u->read_buffers.next, struct read_buffer, list);
i = 0;
while (i < len) {
- unsigned sz = min((unsigned)len - i, rb->len - rb->cons);
+ size_t sz = min_t(size_t, len - i, rb->len - rb->cons);
ret = copy_to_user(ubuf + i, &rb->msg[rb->cons], sz);