[PATCH] Fix pointer arithmetic in hpt3xx driver code (3rd try)

Masoud Sharbiani
2008-09-06T17:19:37Z

git commit 74811f355f4f69a187fa74892dcf2a684b84ce99 causes crash at
module load (or boot) time on my machine with a hpt374 controller.
The reason for this is that for initializing second controller which sets
(hwif->dev == host->dev[1]) to true (1), adds 1 to a void ptr, which
advances it by one byte instead of advancing it by sizeof(hpt_info) bytes.
Because of this, all initialization functions get corrupted data in info
variable which causes a crash at boot time.

This patch fixes that and makes my machine boot again.

The card itself is a HPT374 raid conroller: Here is the lspci -v output:
03:06.0 RAID bus controller: HighPoint Technologies, Inc. HPT374 (rev
07)
Subsystem: HighPoint Technologies, Inc. Unknown device 0001
Flags: bus master, 66MHz, medium devsel, latency 120, IRQ 28
I/O ports at 8000 [size=8]
I/O ports at 7800 [size=4]
I/O ports at 7400 [size=8]
I/O ports at 7000 [size=4]
I/O ports at 6800 [size=256]
Expansion ROM at fe8e0000 [disabled] [size=128K]
Capabilities: [60] Power Management version 2

03:06.1 RAID bus controller: HighPoint Technologies, Inc. HPT374 (rev
07)
Subsystem: HighPoint Technologies, Inc. Unknown device 0001
Flags: bus master, 66MHz, medium devsel, latency 120, IRQ 28
I/O ports at 9800 [size=8]
I/O ports at 9400 [size=4]
I/O ports at 9000 [size=8]
I/O ports at 8800 [size=4]
I/O ports at 8400 [size=256]
Capabilities: [60] Power Management version 2

Signed-Off-By: Masoud Sharbiani <masouds@google.com>

diff --git a/drivers/ide/pci/hpt366.c b/drivers/ide/pci/hpt366.c
index eb107ee..4eae284 100644
--- a/drivers/ide/pci/hpt366.c
+++ b/drivers/ide/pci/hpt366.c
@@ -613,6 +613,14 @@ static int check_in_drive_list(ide_drive_t *drive, const char **list)
return 0;
}

+static struct hpt_info *hpt3xx_get_info(struct device *dev)
+{
+ struct ide_host *host = pci_get_drvdata(to_pci_dev(pci_dev));
+ struct hpt_info *info = (struct hpt_info *)host->host_priv;
+
+ return dev == host->dev[1] ? info + 1 : info;
+}
+
/*
* The Marvell bridge chips used on the HighPoint SATA cards do not seem
* to support the UltraDMA modes 1, 2, and 3 as well as any MWDMA modes...
@@ -621,9 +629,7 @@ static int check_in_drive_list(ide_drive_t *drive, const char **list)
static u8 hpt3xx_udma_filter(ide_drive_t *drive)
{
ide_hwif_t *hwif = HWIF(drive);
- struct pci_dev *dev = to_pci_dev(hwif->dev);
- struct ide_host *host = pci_get_drvdata(dev);
- struct hpt_info *info = host->host_priv + (hwif->dev == host->dev[1]);
+ struct hpt_info *info = hpt3xx_get_info(hwif->dev);
u8 mask = hwif->ultra_mask;

switch (info->chip_type) {
@@ -662,9 +668,7 @@ static u8 hpt3xx_udma_filter(ide_drive_t *drive)
static u8 hpt3xx_mdma_filter(ide_drive_t *drive)
{
ide_hwif_t *hwif = HWIF(drive);
- struct pci_dev *dev = to_pci_dev(hwif->dev);
- struct ide_host *host = pci_get_drvdata(dev);
- struct hpt_info *info = host->host_priv + (hwif->dev == host->dev[1]);
+ struct hpt_info *info = hpt3xx_get_info(hwif->dev);

switch (info->chip_type) {
case HPT372 :
@@ -700,8 +704,7 @@ static void hpt3xx_set_mode(ide_drive_t *drive, const u8 speed)
{
ide_hwif_t *hwif = drive->hwif;
struct pci_dev *dev = to_pci_dev(hwif->dev);
- struct ide_host *host = pci_get_drvdata(dev);
- struct hpt_info *info = host->host_priv + (hwif->dev == host->dev[1]);
+ struct hpt_info *info = hpt3xx_get_info(hwif->dev);
struct hpt_timings *t = info->timings;
u8 itr_addr = 0x40 + (drive->dn * 4);
u32 old_itr = 0;
@@ -744,8 +747,7 @@ static void hpt3xx_maskproc(ide_drive_t *drive, int mask)
{
ide_hwif_t *hwif = HWIF(drive);
struct pci_dev *dev = to_pci_dev(hwif->dev);
- struct ide_host *host = pci_get_drvdata(dev);
- struct hpt_info *info = host->host_priv + (hwif->dev == host->dev[1]);
+ struct hpt_info *info = hpt3xx_get_info(hwif->dev);

if (drive->quirk_list) {
if (info->chip_type >= HPT370) {
@@ -973,8 +975,7 @@ static int __devinit hpt37x_calibrate_dpll(struct pci_dev *dev, u16 f_low, u16 f
static unsigned int __devinit init_chipset_hpt366(struct pci_dev *dev)
{
unsigned long io_base = pci_resource_start(dev, 4);
- struct ide_host *host = pci_get_drvdata(dev);
- struct hpt_info *info = host->host_priv + (&dev->dev == host->dev[1]);
+ struct hpt_info *info = hpt3xx_get_info(&dev->dev);
const char *name = DRV_NAME;
u8 pci_clk, dpll_clk = 0; /* PCI and DPLL clock in MHz */
u8 chip_type;
@@ -1217,8 +1218,7 @@ static unsigned int __devinit init_chipset_hpt366(struct pci_dev *dev)
static u8 hpt3xx_cable_detect(ide_hwif_t *hwif)
{
struct pci_dev *dev = to_pci_dev(hwif->dev);
- struct ide_host *host = pci_get_drvdata(dev);
- struct hpt_info *info = host->host_priv + (hwif->dev == host->dev[1]);
+ struct hpt_info *info = hpt3xx_get_info(hwif->dev);
u8 chip_type = info->chip_type;
u8 scr1 = 0, ata66 = hwif->channel ? 0x01 : 0x02;

@@ -1262,8 +1262,7 @@ static u8 hpt3xx_cable_detect(ide_hwif_t *hwif)
static void __devinit init_hwif_hpt366(ide_hwif_t *hwif)
{
struct pci_dev *dev = to_pci_dev(hwif->dev);
- struct ide_host *host = pci_get_drvdata(dev);
- struct hpt_info *info = host->host_priv + (hwif->dev == host->dev[1]);
+ struct hpt_info *info = hpt3xx_get_info(hwif->dev);
int serialize = HPT_SERIALIZE_IO;
u8 chip_type = info->chip_type;
u8 new_mcr, old_mcr = 0;