[PATCH] crash utility: fix max_mapnr issue on system has over 44-bit addressing

[Jingbai Ma]

The patch will add support for new compressed dumpfile header_version 6.

This bug was posted here:
http://lists.infradead.org/pipermail/kexec/2013-September/009587.html

This patch will add a new field in struct kdump_sub_header.
unsigned long   max_mapnr;

And the old "unsigned int max_mapnr" in struct disk_dump_header will
not be used anymore. But still be there for compatibility purpose.

Signed-off-by: Jingbai Ma <jingbai.ma at hp.com>
---
 diskdump.c |   36 +++++++++++++++++++++++++-----------
 diskdump.h |    5 ++++-
 2 files changed, 29 insertions(+), 12 deletions(-)

diff --git a/diskdump.c b/diskdump.c
index 0819a3f..8a2928b 100644
--- a/diskdump.c
+++ b/diskdump.c
@@ -199,22 +199,23 @@ get_bit(char *map, int byte, int bit)
 }
 
 static inline int 
-page_is_ram(unsigned int nr)
+page_is_ram(unsigned long nr)
 {
 	return get_bit(dd->bitmap, nr >> 3, nr & 7);
 }
 
 static inline int 
-page_is_dumpable(unsigned int nr)
+page_is_dumpable(unsigned long nr)
 {
 	return dd->dumpable_bitmap[nr>>3] & (1 << (nr & 7));
 }
 
 static inline int 
-dump_is_partial(const struct disk_dump_header *header)
+dump_is_partial(const struct disk_dump_header *header,
+	const struct kdump_sub_header *sub_header)
 {
 	return header->bitmap_blocks >=
-	    divideup(divideup(header->max_mapnr, 8), dd->block_size) * 2;
+	    divideup(divideup(sub_header->max_mapnr, 8), dd->block_size) * 2;
 }
 
 static int 
@@ -321,6 +322,7 @@ x86_process_elf_notes(void *note_ptr, unsigned long size_note)
  * [40]    unsigned long   size_note;          /  header_version 4 and later  /
  * [44]    off_t           offset_eraseinfo;   /  header_version 5 and later  /
  * [52]    unsigned long   size_eraseinfo;     /  header_version 5 and later  /
+ * [56]    unsigned long   max_mapnr;          /  header_version 6 and later  /
  * };
  * 
  * But when compiled on an ARM processor, each 64-bit "off_t" would be pushed
@@ -338,6 +340,7 @@ x86_process_elf_notes(void *note_ptr, unsigned long size_note)
  * [48]    unsigned long   size_note;          /  header_version 4 and later  /
  * [56]    off_t           offset_eraseinfo;   /  header_version 5 and later  /
  * [62]    unsigned long   size_eraseinfo;     /  header_version 5 and later  /
+ * [66]    unsigned long   max_mapnr;          /  header_version 6 and later  /
  * };
  * 
  */
@@ -357,6 +360,7 @@ struct kdump_sub_header_ARM_target {
 	int 		pad3;	
         off_t           offset_eraseinfo;   /* header_version 5 and later */
         unsigned long   size_eraseinfo;     /* header_version 5 and later */
+	unsigned long	max_mapnr;	    /* header_version 6 and later */
 };
 
 static void
@@ -380,6 +384,8 @@ arm_kdump_header_adjust(int header_version)
 		kdsh->offset_eraseinfo = kdsh_ARM_target->offset_eraseinfo;
 		kdsh->size_eraseinfo = kdsh_ARM_target->size_eraseinfo;
 	}
+	if (header_version >= 6)
+		kdsh->max_mapnr = kdsh_ARM_target->map_mapnr;
 }
 #endif  /* __i386__ && ARM */
 
@@ -578,7 +584,10 @@ restart:
 		}
 	}
 
-	if (dump_is_partial(header))
+	if (header->header_version < 6)
+		sub_header_kdump->max_mapnr = header->max_mapnr;
+
+	if (dump_is_partial(header, sub_header_kdump))
 		memcpy(dd->dumpable_bitmap, dd->bitmap + bitmap_len/2,
 		       bitmap_len/2);
 	else
@@ -679,7 +688,8 @@ restart:
 	}
 
 	if (!is_split) {
-		max_sect_len = divideup(header->max_mapnr, BITMAP_SECT_LEN);
+		max_sect_len = divideup(sub_header_kdump->max_mapnr,
+			BITMAP_SECT_LEN);
 		pfn = 0;
 		dd->filename = file;
 	}
@@ -1058,14 +1068,14 @@ read_diskdump(int fd, void *bufptr, int cnt, ulong addr, physaddr_t paddr)
 	curpaddr = paddr & ~((physaddr_t)(dd->block_size-1));
 	page_offset = paddr & ((physaddr_t)(dd->block_size-1));
 
-	if ((pfn >= dd->header->max_mapnr) || !page_is_ram(pfn)) {
+	if ((pfn >= dd->sub_header_kdump->max_mapnr) || !page_is_ram(pfn)) {
 		if (CRASHDEBUG(8)) {
 			fprintf(fp, "read_diskdump: SEEK_ERROR: "
 			    "paddr/pfn: %llx/%lx ",
 				(ulonglong)paddr, pfn);
-			if (pfn >= dd->header->max_mapnr)
-				fprintf(fp, "max_mapnr: %x\n",
-					dd->header->max_mapnr);
+			if (pfn >= dd->sub_header_kdump->max_mapnr)
+				fprintf(fp, "max_mapnr: %lx\n",
+					dd->sub_header_kdump->max_mapnr);
 			else
 				fprintf(fp, "!page_is_ram\n");
 		}
@@ -1517,7 +1527,11 @@ __diskdump_memory_dump(FILE *fp)
 	fprintf(fp, "          block_size: %d\n", dh->block_size);
 	fprintf(fp, "        sub_hdr_size: %d\n", dh->sub_hdr_size);
 	fprintf(fp, "       bitmap_blocks: %u\n", dh->bitmap_blocks);
-	fprintf(fp, "           max_mapnr: %u\n", dh->max_mapnr);
+	if (dh->header_version >= 6)
+		fprintf(fp, "           max_mapnr: %lu\n",
+			dd->sub_header_kdump->max_mapnr);
+	else
+		fprintf(fp, "           max_mapnr: %u\n", dh->max_mapnr);
 	fprintf(fp, "    total_ram_blocks: %u\n", dh->total_ram_blocks);
 	fprintf(fp, "       device_blocks: %u\n", dh->device_blocks);
 	fprintf(fp, "      written_blocks: %u\n", dh->written_blocks);
diff --git a/diskdump.h b/diskdump.h
index 9ab10b6..17642b6 100644
--- a/diskdump.h
+++ b/diskdump.h
@@ -42,7 +42,9 @@ struct disk_dump_header {
 						   header in blocks */
 	unsigned int		bitmap_blocks;	/* Size of Memory bitmap in
 						   block */
-	unsigned int		max_mapnr;	/* = max_mapnr */
+	unsigned int		max_mapnr;	/* = max_mapnr, 32bit only,
+						   full 64bit in sub header.
+						   Do NOT use this anymore! */
 	unsigned int		total_ram_blocks;/* Number of blocks should be
 						   written */
 	unsigned int		device_blocks;	/* Number of total blocks in
@@ -69,6 +71,7 @@ struct kdump_sub_header {
 	unsigned long	size_note;          /* header_version 4 and later */
 	off_t		offset_eraseinfo;   /* header_version 5 and later */
 	unsigned long	size_eraseinfo;     /* header_version 5 and later */
+	unsigned long	max_mapnr;          /* header_version 6 and later */
 };
 
 /* page flags */