This is a note to let you know that I've just added the patch titled
ata: libata-core: Fix ata_port_request_pm() locking
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ata-libata-core-fix-ata_port_request_pm-locking.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 3b8e0af4a7a331d1510e963b8fd77e2fca0a77f1 Mon Sep 17 00:00:00 2001
From: Damien Le Moal <dlemoal@xxxxxxxxxx>
Date: Mon, 4 Sep 2023 20:38:13 +0900
Subject: ata: libata-core: Fix ata_port_request_pm() locking
From: Damien Le Moal <dlemoal@xxxxxxxxxx>
commit 3b8e0af4a7a331d1510e963b8fd77e2fca0a77f1 upstream.
The function ata_port_request_pm() checks the port flag
ATA_PFLAG_PM_PENDING and calls ata_port_wait_eh() if this flag is set to
ensure that power management operations for a port are not scheduled
simultaneously. However, this flag check is done without holding the
port lock.
Fix this by taking the port lock on entry to the function and checking
the flag under this lock. The lock is released and re-taken if
ata_port_wait_eh() needs to be called. The two WARN_ON() macros checking
that the ATA_PFLAG_PM_PENDING flag was cleared are removed as the first
call is racy and the second one done without holding the port lock.
Fixes: 5ef41082912b ("ata: add ata port system PM callbacks")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
Tested-by: Chia-Lin Kao (AceLan) <acelan.kao@xxxxxxxxxxxxx>
Reviewed-by: Niklas Cassel <niklas.cassel@xxxxxxx>
Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
Reviewed-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Reviewed-by: Bart Van Assche <bvanassche@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/ata/libata-core.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5756,17 +5756,19 @@ static void ata_port_request_pm(struct a
struct ata_link *link;
unsigned long flags;
- /* Previous resume operation might still be in
- * progress. Wait for PM_PENDING to clear.
+ spin_lock_irqsave(ap->lock, flags);
+
+ /*
+ * A previous PM operation might still be in progress. Wait for
+ * ATA_PFLAG_PM_PENDING to clear.
*/
if (ap->pflags & ATA_PFLAG_PM_PENDING) {
+ spin_unlock_irqrestore(ap->lock, flags);
ata_port_wait_eh(ap);
- WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
+ spin_lock_irqsave(ap->lock, flags);
}
- /* request PM ops to EH */
- spin_lock_irqsave(ap->lock, flags);
-
+ /* Request PM operation to EH */
ap->pm_mesg = mesg;
ap->pflags |= ATA_PFLAG_PM_PENDING;
ata_for_each_link(link, ap, HOST_FIRST) {
@@ -5778,10 +5780,8 @@ static void ata_port_request_pm(struct a
spin_unlock_irqrestore(ap->lock, flags);
- if (!async) {
+ if (!async)
ata_port_wait_eh(ap);
- WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
- }
}
/*
Patches currently in stable-queue which might be from dlemoal@xxxxxxxxxx are
queue-4.19/ata-libata-core-do-not-register-pm-operations-for-sas-ports.patch
queue-4.19/ata-libata-sata-increase-pmp-srst-timeout-to-10s.patch
queue-4.19/ata-libata-scsi-ignore-reserved-bits-for-report-supported-operation-codes.patch
queue-4.19/ata-libata-core-fix-ata_port_request_pm-locking.patch
queue-4.19/ata-libahci-clear-pending-interrupt-status.patch
queue-4.19/ata-libata-eh-do-not-clear-ata_pflag_eh_pending-in-a.patch
queue-4.19/ata-libata-core-fix-port-and-device-removal.patch
