To move the list iterator variable into the list_for_each_entry_*()
macro in the future it should be avoided to use the list iterator
variable after the loop body.
To *never* use the list iterator variable after the loop it was
concluded to use a separate iterator variable [1].
Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1]
Signed-off-by: Jakob Koschel <[email protected]>
---
v1: https://lore.kernel.org/lkml/[email protected]/
Changelog:
v1->v2:
* remove possible NULL ptr dereference bug in bcm_vk_read (Dan Carpenter)
drivers/misc/bcm-vk/bcm_vk_msg.c | 25 ++++++++++++-------------
1 file changed, 12 insertions(+), 13 deletions(-)
diff --git a/drivers/misc/bcm-vk/bcm_vk_msg.c b/drivers/misc/bcm-vk/bcm_vk_msg.c
index 066b9ef7fcd7..923fbcb73f2a 100644
--- a/drivers/misc/bcm-vk/bcm_vk_msg.c
+++ b/drivers/misc/bcm-vk/bcm_vk_msg.c
@@ -757,20 +757,19 @@ static struct bcm_vk_wkent *bcm_vk_dequeue_pending(struct bcm_vk *vk,
u16 q_num,
u16 msg_id)
{
- bool found = false;
- struct bcm_vk_wkent *entry;
+ struct bcm_vk_wkent *entry = NULL, *iter;
spin_lock(&chan->pendq_lock);
- list_for_each_entry(entry, &chan->pendq[q_num], node) {
- if (get_msg_id(&entry->to_v_msg[0]) == msg_id) {
- list_del(&entry->node);
- found = true;
+ list_for_each_entry(iter, &chan->pendq[q_num], node) {
+ if (get_msg_id(&iter->to_v_msg[0]) == msg_id) {
+ list_del(&iter->node);
+ entry = iter;
bcm_vk_msgid_bitmap_clear(vk, msg_id, 1);
break;
}
}
spin_unlock(&chan->pendq_lock);
- return ((found) ? entry : NULL);
+ return entry;
}
s32 bcm_to_h_msg_dequeue(struct bcm_vk *vk)
@@ -1010,7 +1009,7 @@ ssize_t bcm_vk_read(struct file *p_file,
miscdev);
struct device *dev = &vk->pdev->dev;
struct bcm_vk_msg_chan *chan = &vk->to_h_msg_chan;
- struct bcm_vk_wkent *entry = NULL;
+ struct bcm_vk_wkent *entry = NULL, *iter;
u32 q_num;
u32 rsp_length;
bool found = false;
@@ -1019,7 +1018,6 @@ ssize_t bcm_vk_read(struct file *p_file,
return -EPERM;
dev_dbg(dev, "Buf count %zu\n", count);
- found = false;
/*
* search through the pendq on the to_h chan, and return only those
@@ -1028,17 +1026,18 @@ ssize_t bcm_vk_read(struct file *p_file,
*/
spin_lock(&chan->pendq_lock);
for (q_num = 0; q_num < chan->q_nr; q_num++) {
- list_for_each_entry(entry, &chan->pendq[q_num], node) {
- if (entry->ctx->idx == ctx->idx) {
+ list_for_each_entry(iter, &chan->pendq[q_num], node) {
+ if (iter->ctx->idx == ctx->idx) {
if (count >=
- (entry->to_h_blks * VK_MSGQ_BLK_SIZE)) {
- list_del(&entry->node);
+ (iter->to_h_blks * VK_MSGQ_BLK_SIZE)) {
+ list_del(&iter->node);
atomic_dec(&ctx->pend_cnt);
found = true;
} else {
/* buffer not big enough */
rc = -EMSGSIZE;
}
+ entry = iter;
goto read_loop_exit;
}
}
base-commit: 46cf2c613f4b10eb12f749207b0fd2c1bfae3088
--
2.25.1