On 05/31/2017 06:18 PM, Sumit Saxena wrote:
-----Original Message-----
From: Jia-Ju Bai [mailto:baijiaju1990@xxxxxxx]
Sent: Wednesday, May 31, 2017 8:27 AM
To: kashyap.desai@xxxxxxxxxxxx; sumit.saxena@xxxxxxxxxxxx;
shivasharan.srikanteshwara@xxxxxxxxxxxx; jejb@xxxxxxxxxxxxxxxxxx;
martin.petersen@xxxxxxxxxx
Cc: megaraidlinux.pdl@xxxxxxxxxxxx; linux-scsi@xxxxxxxxxxxxxxx; linux-
kernel@xxxxxxxxxxxxxxx; Jia-Ju Bai
Subject: [PATCH] megaraid: Fix a sleep-in-atomic bug
The driver may sleep under a spin lock, and the function call path is:
mraid_mm_attach_buf (acquire the lock by spin_lock_irqsave)
pci_pool_alloc(GFP_KERNEL) --> may sleep
To fix it, the "GFP_KERNEL" is replaced with "GFP_ATOMIC".
Signed-off-by: Jia-Ju Bai<baijiaju1990@xxxxxxx>
---
drivers/scsi/megaraid/megaraid_mm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/scsi/megaraid/megaraid_mm.c
b/drivers/scsi/megaraid/megaraid_mm.c
index 4cf9ed9..c43afb8 100644
--- a/drivers/scsi/megaraid/megaraid_mm.c
+++ b/drivers/scsi/megaraid/megaraid_mm.c
@@ -574,7 +574,7 @@
kioc->pool_index = right_pool;
kioc->free_buf = 1;
- kioc->buf_vaddr = pci_pool_alloc(pool->handle, GFP_KERNEL,
+ kioc->buf_vaddr = pci_pool_alloc(pool->handle, GFP_ATOMIC,
&kioc->buf_paddr);
spin_unlock_irqrestore(&pool->lock, flags);
This is very old driver and reached EOL. Did you face any issue because of
this bug or discover this through code review?
Anyways patch looks good to me.
Acked-by: Sumit Saxena<sumit.saxena@xxxxxxxxxxxx>
--
1.7.9.5
Hi,
This bug is found by a static analysis tool and my code review.
Jia-Ju Bai
