[PATCH 3/7] Don't use a sector buffer on stack

[Juergen Beisert]

Using a temp. buffer for a disk sector on the stack, seems not work. Doing so
lets the system run crazy (the stack seems to be destroyd). Don't know the
correct stack handling on ARM, but (IMHO) I also can exclude any writing across
the buffer boundaries.

Using a temp. buffer via malloc() runs also on ARM.

Note: This patch was required to add MCI card support, which can be handled
like a disk drive.

Signed-off-by: Juergen Beisert <jbe at pengutronix.de>
---
 drivers/ata/disk_drive.c |   17 ++++++++++++-----
 1 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/ata/disk_drive.c b/drivers/ata/disk_drive.c
index a54a283..e9d855b 100644
--- a/drivers/ata/disk_drive.c
+++ b/drivers/ata/disk_drive.c
@@ -34,6 +34,7 @@
 #include <errno.h>
 #include <string.h>
 #include <linux/kernel.h>
+#include <malloc.h>
 
 /**
  * Description of one partition table entry (D*S type)
@@ -268,15 +269,18 @@ static struct file_operations disk_ops = {
  */
 static int disk_probe(struct device_d *dev)
 {
-	uint8_t sector[512];
+	uint8_t *sector;
 	int rc;
 	struct ata_interface *intf = dev->platform_data;
 	struct cdev *disk_cdev;
 
+	sector = xmalloc(SECTOR_SIZE);
+
 	rc = intf->read(dev, 0, 1, sector);
 	if (rc != 0) {
 		dev_err(dev, "Cannot read MBR of this device\n");
-		return -1;
+		rc = -ENODEV;
+		goto on_error;
 	}
 
 	/* It seems a valuable disk. Register it */
@@ -305,7 +309,8 @@ static int disk_probe(struct device_d *dev)
 
 	if ((sector[510] != 0x55) || (sector[511] != 0xAA)) {
 		dev_info(dev, "No partition table found\n");
-		return 0;
+		rc = 0;
+		goto on_error;
 	}
 
 	/* guess the size of this drive */
@@ -313,9 +318,11 @@ static int disk_probe(struct device_d *dev)
 	dev_info(dev, "Drive size guessed to %u kiB\n", dev->size / 1024);
 	disk_cdev->size = dev->size;
 
-	disk_register_partitions(dev, (struct partition_entry*)&sector[446]);
+	rc = disk_register_partitions(dev, (struct partition_entry*)&sector[446]);
 
-	return 0;
+on_error:
+	free(sector);
+	return rc;
 }
 
 #ifdef CONFIG_ATA_BIOS
-- 
1.7.2.3