From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sumit Saxena Subject: RE: [PATCH] megaraid: Fix a sleep-in-atomic bug Date: Wed, 31 May 2017 15:48:03 +0530 Message-ID: References: <1496199416-2556-1-git-send-email-baijiaju1990@163.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Return-path: In-Reply-To: <1496199416-2556-1-git-send-email-baijiaju1990@163.com> Sender: linux-kernel-owner@vger.kernel.org To: Jia-Ju Bai , Kashyap Desai , Shivasharan Srikanteshwara , jejb@linux.vnet.ibm.com, martin.petersen@oracle.com Cc: "PDL,MEGARAIDLINUX" , linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-scsi@vger.kernel.org >-----Original Message----- >From: Jia-Ju Bai [mailto:baijiaju1990@163.com] >Sent: Wednesday, May 31, 2017 8:27 AM >To: kashyap.desai@broadcom.com; sumit.saxena@broadcom.com; >shivasharan.srikanteshwara@broadcom.com; jejb@linux.vnet.ibm.com; >martin.petersen@oracle.com >Cc: megaraidlinux.pdl@broadcom.com; linux-scsi@vger.kernel.org; linux- >kernel@vger.kernel.org; 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 >--- > 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 > >-- >1.7.9.5 >