linux-kernel - [PATCH 228/241] sata_svw: check DMA start bit before reset

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1355407206-17100-229-git-send-email-herton.krzesinski@canonical.com>
Date:	Thu, 13 Dec 2012 11:59:53 -0200
From:	Herton Ronaldo Krzesinski <herton.krzesinski@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	David Milburn <dmilburn@...hat.com>,
	Jeff Garzik <jgarzik@...hat.com>,
	Herton Ronaldo Krzesinski <herton.krzesinski@...onical.com>
Subject: [PATCH 228/241] sata_svw: check DMA start bit before reset

3.5.7.2 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Milburn <dmilburn@...hat.com>

commit b03e66a6be91f8389fcd902ab6c1563db1c9c06b upstream.

If kdump is triggered with pending IO, controller may not respond causing
kdump to fail.

http://marc.info/?l=linux-ide&m=133032255424658&w=2

During error recovery ata_do_dev_read_id never completes due hang
in mmio_insw.

ata_do_dev_read_id
 ata_sff_data_xfer
  ioread16_rep
   mmio_insw

if DMA start bit is cleared before reset, PIO command is successful
and kdump succeeds.

Signed-off-by: David Milburn <dmilburn@...hat.com>
Signed-off-by: Jeff Garzik <jgarzik@...hat.com>
Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@...onical.com>
---
 drivers/ata/sata_svw.c |   35 +++++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/ata/sata_svw.c b/drivers/ata/sata_svw.c
index c646118..833607f 100644
--- a/drivers/ata/sata_svw.c
+++ b/drivers/ata/sata_svw.c
@@ -142,6 +142,39 @@ static int k2_sata_scr_write(struct ata_link *link,
 	return 0;
 }
 
+static int k2_sata_softreset(struct ata_link *link,
+			     unsigned int *class, unsigned long deadline)
+{
+	u8 dmactl;
+	void __iomem *mmio = link->ap->ioaddr.bmdma_addr;
+
+	dmactl = readb(mmio + ATA_DMA_CMD);
+
+	/* Clear the start bit */
+	if (dmactl & ATA_DMA_START) {
+		dmactl &= ~ATA_DMA_START;
+		writeb(dmactl, mmio + ATA_DMA_CMD);
+	}
+
+	return ata_sff_softreset(link, class, deadline);
+}
+
+static int k2_sata_hardreset(struct ata_link *link,
+			     unsigned int *class, unsigned long deadline)
+{
+	u8 dmactl;
+	void __iomem *mmio = link->ap->ioaddr.bmdma_addr;
+
+	dmactl = readb(mmio + ATA_DMA_CMD);
+
+	/* Clear the start bit */
+	if (dmactl & ATA_DMA_START) {
+		dmactl &= ~ATA_DMA_START;
+		writeb(dmactl, mmio + ATA_DMA_CMD);
+	}
+
+	return sata_sff_hardreset(link, class, deadline);
+}
 
 static void k2_sata_tf_load(struct ata_port *ap, const struct ata_taskfile *tf)
 {
@@ -346,6 +379,8 @@ static struct scsi_host_template k2_sata_sht = {
 
 static struct ata_port_operations k2_sata_ops = {
 	.inherits		= &ata_bmdma_port_ops,
+	.softreset              = k2_sata_softreset,
+	.hardreset              = k2_sata_hardreset,
 	.sff_tf_load		= k2_sata_tf_load,
 	.sff_tf_read		= k2_sata_tf_read,
 	.sff_check_status	= k2_stat_check_status,
-- 
1.7.9.5

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/