There are sleep in atomic context bugs when dm_fsync_timer_callback is
executing. The root cause is that the memory allocation functions with
GFP_KERNEL parameter are called in dm_fsync_timer_callback which is a
timer handler. The call paths that could trigger bugs are shown below:
(interrupt context)
dm_fsync_timer_callback
write_nic_byte
kzalloc(sizeof(data), GFP_KERNEL); //may sleep
write_nic_dword
kzalloc(sizeof(data), GFP_KERNEL); //may sleep
This patch changes allocation mode from GFP_KERNEL to GFP_ATOMIC
in order to prevent atomic context sleeping. The GFP_ATOMIC flag
makes memory allocation operation could be used in atomic context.
Signed-off-by: Duoming Zhou <duoming@xxxxxxxxxx>
---
drivers/staging/rtl8192u/r8192U_core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/rtl8192u/r8192U_core.c b/drivers/staging/rtl8192u/r8192U_core.c
index ce807c9d421..679c362baad 100644
--- a/drivers/staging/rtl8192u/r8192U_core.c
+++ b/drivers/staging/rtl8192u/r8192U_core.c
@@ -267,7 +267,7 @@ int write_nic_byte(struct net_device *dev, int indx, u8 data)
struct r8192_priv *priv = (struct r8192_priv *)ieee80211_priv(dev);
struct usb_device *udev = priv->udev;
- u8 *usbdata = kzalloc(sizeof(data), GFP_KERNEL);
+ u8 *usbdata = kzalloc(sizeof(data), GFP_ATOMIC);
if (!usbdata)
return -ENOMEM;
@@ -319,7 +319,7 @@ int write_nic_dword(struct net_device *dev, int indx, u32 data)
struct r8192_priv *priv = (struct r8192_priv *)ieee80211_priv(dev);
struct usb_device *udev = priv->udev;
- u32 *usbdata = kzalloc(sizeof(data), GFP_KERNEL);
+ u32 *usbdata = kzalloc(sizeof(data), GFP_ATOMIC);
if (!usbdata)
return -ENOMEM;
--
2.17.1
