From: Christophe JAILLET <christophe.jaillet@wanadoo.fr> To: JBottomley@odin.com Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Christophe JAILLET <christophe.jaillet@wanadoo.fr> Subject: [PATCH] arcmsr: Fix a potential data corruption issue Date: Fri, 10 Jul 2015 07:18:10 +0200 [thread overview] Message-ID: <1436505490-9640-1-git-send-email-christophe.jaillet@wanadoo.fr> (raw) Resetting rqbuffer or wqbuffer must be done within a critial section in order to avoir potential data corruption. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- This change is *untested* because I don't have the corresponding hardware. However, it should'nt have any evil side effect (just a few lines of code moved from outside to within a spin_lock) This just a "guess" based on the other uses of the 2 buffers within the code. It is also inspired on how things are done in arcmsr_hba.c (see line #2390) So please ignore if not relevant. --- drivers/scsi/arcmsr/arcmsr_attr.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/arcmsr/arcmsr_attr.c b/drivers/scsi/arcmsr/arcmsr_attr.c index 9c86481..2ad970d 100644 --- a/drivers/scsi/arcmsr/arcmsr_attr.c +++ b/drivers/scsi/arcmsr/arcmsr_attr.c @@ -171,22 +171,21 @@ static ssize_t arcmsr_sysfs_iop_message_clear(struct file *filp, return -EACCES; arcmsr_clear_iop2drv_rqueue_buffer(acb); - acb->acb_flags |= - (ACB_F_MESSAGE_WQBUFFER_CLEARED - | ACB_F_MESSAGE_RQBUFFER_CLEARED - | ACB_F_MESSAGE_WQBUFFER_READED); spin_lock_irqsave(&acb->rqbuffer_lock, flags); + acb->acb_flags |= ACB_F_MESSAGE_RQBUFFER_CLEARED; acb->rqbuf_getIndex = 0; acb->rqbuf_putIndex = 0; + pQbuffer = acb->rqbuffer; + memset(pQbuffer, 0, sizeof (struct QBUFFER)); spin_unlock_irqrestore(&acb->rqbuffer_lock, flags); spin_lock_irqsave(&acb->wqbuffer_lock, flags); + acb->acb_flags |= (ACB_F_MESSAGE_WQBUFFER_CLEARED | + ACB_F_MESSAGE_WQBUFFER_READED); acb->wqbuf_getIndex = 0; acb->wqbuf_putIndex = 0; - spin_unlock_irqrestore(&acb->wqbuffer_lock, flags); - pQbuffer = acb->rqbuffer; - memset(pQbuffer, 0, sizeof (struct QBUFFER)); pQbuffer = acb->wqbuffer; memset(pQbuffer, 0, sizeof (struct QBUFFER)); + spin_unlock_irqrestore(&acb->wqbuffer_lock, flags); return 1; } -- 2.1.4
WARNING: multiple messages have this Message-ID (diff)
From: Christophe JAILLET <christophe.jaillet@wanadoo.fr> To: JBottomley@odin.com Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org, Christophe JAILLET <christophe.jaillet@wanadoo.fr> Subject: [PATCH] arcmsr: Fix a potential data corruption issue Date: Fri, 10 Jul 2015 05:18:10 +0000 [thread overview] Message-ID: <1436505490-9640-1-git-send-email-christophe.jaillet@wanadoo.fr> (raw) Resetting rqbuffer or wqbuffer must be done within a critial section in order to avoir potential data corruption. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> --- This change is *untested* because I don't have the corresponding hardware. However, it should'nt have any evil side effect (just a few lines of code moved from outside to within a spin_lock) This just a "guess" based on the other uses of the 2 buffers within the code. It is also inspired on how things are done in arcmsr_hba.c (see line #2390) So please ignore if not relevant. --- drivers/scsi/arcmsr/arcmsr_attr.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/arcmsr/arcmsr_attr.c b/drivers/scsi/arcmsr/arcmsr_attr.c index 9c86481..2ad970d 100644 --- a/drivers/scsi/arcmsr/arcmsr_attr.c +++ b/drivers/scsi/arcmsr/arcmsr_attr.c @@ -171,22 +171,21 @@ static ssize_t arcmsr_sysfs_iop_message_clear(struct file *filp, return -EACCES; arcmsr_clear_iop2drv_rqueue_buffer(acb); - acb->acb_flags |- (ACB_F_MESSAGE_WQBUFFER_CLEARED - | ACB_F_MESSAGE_RQBUFFER_CLEARED - | ACB_F_MESSAGE_WQBUFFER_READED); spin_lock_irqsave(&acb->rqbuffer_lock, flags); + acb->acb_flags |= ACB_F_MESSAGE_RQBUFFER_CLEARED; acb->rqbuf_getIndex = 0; acb->rqbuf_putIndex = 0; + pQbuffer = acb->rqbuffer; + memset(pQbuffer, 0, sizeof (struct QBUFFER)); spin_unlock_irqrestore(&acb->rqbuffer_lock, flags); spin_lock_irqsave(&acb->wqbuffer_lock, flags); + acb->acb_flags |= (ACB_F_MESSAGE_WQBUFFER_CLEARED | + ACB_F_MESSAGE_WQBUFFER_READED); acb->wqbuf_getIndex = 0; acb->wqbuf_putIndex = 0; - spin_unlock_irqrestore(&acb->wqbuffer_lock, flags); - pQbuffer = acb->rqbuffer; - memset(pQbuffer, 0, sizeof (struct QBUFFER)); pQbuffer = acb->wqbuffer; memset(pQbuffer, 0, sizeof (struct QBUFFER)); + spin_unlock_irqrestore(&acb->wqbuffer_lock, flags); return 1; } -- 2.1.4
next reply other threads:[~2015-07-10 5:18 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2015-07-10 5:18 Christophe JAILLET [this message] 2015-07-10 5:18 ` [PATCH] arcmsr: Fix a potential data corruption issue Christophe JAILLET 2015-07-10 9:25 ` Dan Carpenter 2015-07-10 9:25 ` Dan Carpenter
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