[PATCH] GFP_KERNEL malloc with lock held in net/wireless/mwifiex

From: Thomas Meyer
Date: Thu Aug 04 2011 - 18:06:37 EST


From: Thomas Meyer <thomas@xxxxxxxx>

Find functions that refer to GFP_KERNEL but are called with locks held.
The proposed change of converting the GFP_KERNEL is not necessarily the
correct one. It may be desired to unlock the lock, or to not call the
function under the lock in the first place.

The semantic patch that makes this output is available
in scripts/coccinelle/locks/call_kern.cocci.

More information about semantic patching is available at
http://coccinelle.lip6.fr/

Signed-off-by: Thomas Meyer <thomas@xxxxxxxx>
---
the function mwifiex_save_curr_bcn() is guarded by:

spin_lock_irqsave(&priv->curr_bcn_buf_lock, flags);
mwifiex_save_curr_bcn(priv);
spin_unlock_irqrestore(&priv->curr_bcn_buf_lock, flags);

Is it okay to allocate memory with a spin lock held and interrupts
disabled in this case?

diff -u -p a/drivers/net/wireless/mwifiex/scan.c b/drivers/net/wireless/mwifiex/scan.c
--- a/drivers/net/wireless/mwifiex/scan.c 2011-07-26 00:46:08.483511656 +0200
+++ b/drivers/net/wireless/mwifiex/scan.c 2011-08-02 09:36:50.174808818 +0200
@@ -2998,7 +2998,7 @@ mwifiex_save_curr_bcn(struct mwifiex_pri

kfree(priv->curr_bcn_buf);
priv->curr_bcn_buf = kzalloc(curr_bss->beacon_buf_size,
- GFP_KERNEL);
+ GFP_ATOMIC);
if (!priv->curr_bcn_buf) {
dev_err(priv->adapter->dev,
"failed to alloc curr_bcn_buf\n");


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