[U-Boot] [PATCH] part_dos: allocate sector buffer dynamically

[Sergei Shtylyov]

Apple iPod nanos have sector sizes of 2 or 4 KiB, which crashes U-Boot when it
tries to read the MBR into 512-byte buffer situated on stack. Instead allocate
this buffer dynamically to be safe with any large sector size.

Signed-off-by: Sergei Shtylyov <sshtylyov at ru.mvista.com>

---
The same change is probably needed for disk/part_amiga.c but I'm not really
sure if Amiga supports USB... :-)

 disk/part_dos.c |   59 +++++++++++++++++++++++++++++++++++++++-----------------
 disk/part_dos.h |    7 ------
 2 files changed, 42 insertions(+), 24 deletions(-)

Index: u-boot/disk/part_dos.c
===================================================================
--- u-boot.orig/disk/part_dos.c
+++ u-boot/disk/part_dos.c
@@ -32,6 +32,7 @@
 
 #include <common.h>
 #include <command.h>
+#include <exports.h>
 #include <ide.h>
 #include "part_dos.h"
 
@@ -87,14 +88,20 @@ static int test_block_type(unsigned char
 
 int test_part_dos (block_dev_desc_t *dev_desc)
 {
-	unsigned char buffer[DEFAULT_SECTOR_SIZE];
+	unsigned char *buffer;
+
+	buffer = malloc(dev_desc->blksz);
+	if (!buffer)
+		return -1;
 
 	if ((dev_desc->block_read(dev_desc->dev, 0, 1, (ulong *) buffer) != 1) ||
 	    (buffer[DOS_PART_MAGIC_OFFSET + 0] != 0x55) ||
 	    (buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) ) {
-		return (-1);
+		free(buffer);
+		return -1;
 	}
-	return (0);
+	free(buffer);
+	return 0;
 }
 
 /*  Print a partition that is relative to its Extended partition table
@@ -102,26 +109,32 @@ int test_part_dos (block_dev_desc_t *dev
 static void print_partition_extended (block_dev_desc_t *dev_desc, int ext_part_sector, int relative,
 							   int part_num)
 {
-	unsigned char buffer[DEFAULT_SECTOR_SIZE];
+	unsigned char *buffer;
 	dos_partition_t *pt;
 	int i;
 
+	buffer = malloc(dev_desc->blksz);
+	if (!buffer) {
+		printf ("** Can't allocate buffer **\n");
+		return;
+	}
+
 	if (dev_desc->block_read(dev_desc->dev, ext_part_sector, 1, (ulong *) buffer) != 1) {
 		printf ("** Can't read partition table on %d:%d **\n",
 			dev_desc->dev, ext_part_sector);
-		return;
+		goto exit;
 	}
 	i=test_block_type(buffer);
 	if(i==-1) {
 		printf ("bad MBR sector signature 0x%02x%02x\n",
 			buffer[DOS_PART_MAGIC_OFFSET],
 			buffer[DOS_PART_MAGIC_OFFSET + 1]);
-		return;
+		goto exit;
 	}
 	if(i==DOS_PBR) {
 		printf ("    1\t\t         0\t%10ld\t%2x\n",
 			dev_desc->lba, buffer[DOS_PBR_MEDIA_TYPE_OFFSET]);
-		return;
+		goto exit;
 	}
 	/* Print all primary/logical partitions */
 	pt = (dos_partition_t *) (buffer + DOS_PART_TBL_OFFSET);
@@ -156,7 +169,8 @@ static void print_partition_extended (bl
 		}
 	}
 
-	return;
+exit:
+	free(buffer);
 }
 
 
@@ -166,21 +180,27 @@ static int get_partition_info_extended (
 				 int relative, int part_num,
 				 int which_part, disk_partition_t *info)
 {
-	unsigned char buffer[DEFAULT_SECTOR_SIZE];
+	unsigned char *buffer;
 	dos_partition_t *pt;
-	int i;
+	int i, result = -1;
+
+	buffer = malloc(dev_desc->blksz);
+	if (!buffer) {
+		printf ("** Can't allocate buffer **\n");
+		return -1;
+	}
 
 	if (dev_desc->block_read (dev_desc->dev, ext_part_sector, 1, (ulong *) buffer) != 1) {
 		printf ("** Can't read partition table on %d:%d **\n",
 			dev_desc->dev, ext_part_sector);
-		return -1;
+		goto exit;
 	}
 	if (buffer[DOS_PART_MAGIC_OFFSET] != 0x55 ||
 		buffer[DOS_PART_MAGIC_OFFSET + 1] != 0xaa) {
 		printf ("bad MBR sector signature 0x%02x%02x\n",
 			buffer[DOS_PART_MAGIC_OFFSET],
 			buffer[DOS_PART_MAGIC_OFFSET + 1]);
-		return -1;
+		goto exit;
 	}
 
 	/* Print all primary/logical partitions */
@@ -223,7 +243,8 @@ static int get_partition_info_extended (
 			}
 			/* sprintf(info->type, "%d, pt->sys_ind); */
 			sprintf ((char *)info->type, "U-Boot");
-			return 0;
+			result = 0;
+			goto exit;
 		}
 
 		/* Reverse engr the fdisk part# assignment rule! */
@@ -239,12 +260,16 @@ static int get_partition_info_extended (
 		if (is_extended (pt->sys_ind)) {
 			int lba_start = le32_to_int (pt->start4) + relative;
 
-			return get_partition_info_extended (dev_desc, lba_start,
-				 ext_part_sector == 0 ? lba_start : relative,
-				 part_num, which_part, info);
+			result = get_partition_info_extended(dev_desc,
+					lba_start, ext_part_sector == 0 ?
+						lba_start : relative,
+					part_num, which_part, info);
+			goto exit;
 		}
 	}
-	return -1;
+exit:
+	free(buffer);
+	return result;
 }
 
 void print_part_dos (block_dev_desc_t *dev_desc)
Index: u-boot/disk/part_dos.h
===================================================================
--- u-boot.orig/disk/part_dos.h
+++ u-boot/disk/part_dos.h
@@ -25,13 +25,6 @@
 #define _DISK_PART_DOS_H
 
 
-#ifdef CONFIG_ISO_PARTITION
-/* Make the buffers bigger if ISO partition support is enabled -- CD-ROMS
-   have 2048 byte blocks */
-#define DEFAULT_SECTOR_SIZE	2048
-#else
-#define DEFAULT_SECTOR_SIZE	512
-#endif
 #define DOS_PART_TBL_OFFSET	0x1be
 #define DOS_PART_MAGIC_OFFSET	0x1fe
 #define DOS_PBR_FSTYPE_OFFSET	0x36