From: Elias Oltmanns Date: Mon, 3 Nov 2008 10:01:08 +0000 (+0900) Subject: libata: Fix a potential race condition in ata_scsi_park_show() X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=a464189de350b050aa8f334bd4cc53ed406e56dd;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git libata: Fix a potential race condition in ata_scsi_park_show() Peter Moulder has pointed out that there is a slight chance that a negative value might be passed to jiffies_to_msecs() in ata_scsi_park_show(). This is fixed by saving the value of jiffies in a local variable, thus also reducing code since the volatile variable jiffies is accessed only once. Signed-off-by: Elias Oltmanns Signed-off-by: Tejun Heo Signed-off-by: Jeff Garzik --- diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index bbb30d882f05..3fa75eac135d 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -190,7 +190,7 @@ static ssize_t ata_scsi_park_show(struct device *device, struct ata_port *ap; struct ata_link *link; struct ata_device *dev; - unsigned long flags; + unsigned long flags, now; unsigned int uninitialized_var(msecs); int rc = 0; @@ -208,10 +208,11 @@ static ssize_t ata_scsi_park_show(struct device *device, } link = dev->link; + now = jiffies; if (ap->pflags & ATA_PFLAG_EH_IN_PROGRESS && link->eh_context.unloaded_mask & (1 << dev->devno) && - time_after(dev->unpark_deadline, jiffies)) - msecs = jiffies_to_msecs(dev->unpark_deadline - jiffies); + time_after(dev->unpark_deadline, now)) + msecs = jiffies_to_msecs(dev->unpark_deadline - now); else msecs = 0;