[PATCH v2] makedumpfile: fix max_mapnr issue on system has over 44-bit addressing

Jingbai Ma jingbai.ma at hp.com
Fri Oct 11 05:46:51 EDT 2013


This patch will fix a bug of makedumpfile doesn't work correctly on system
has over 44-bit addressing in compression dump mode.
This bug was posted here:
http://lists.infradead.org/pipermail/kexec/2013-September/009587.html

This patch will add 3 new fields in struct kdump_sub_header.
unsigned long long start_pfn_64;  /* header_version 6 and later */
unsigned long long end_pfn_64;    /* header_version 6 and later */
unsigned long long max_mapnr_64;  /* header_version 6 and later */

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

The max_mapnr_64 only exists in strcut kdump_sub_header, and that only
for compressed kdump format, so for ELF format kdump files (non-compressed),
only the max_mapnr is available, so it still may be truncated for addresses
exceed 44bit (above 16TB).

This patch will change the header_version to 6.

The corresponding patch for crash utility will be sent out separately.

This patch doesn't change sadump_header.

Changelog:
v2:
- Rename max_mapnr in struct kdump_sub_header to max_mapnr_64.
- Change type of max_mapnr_64 from unsigned long to unsigned long long.
  In x86 PAE mode on x86_32 kernel, the address may exceeds 44bit limit.
- Add start_pfn_64, end_pfn_64 for struct kdump_sub_header.
- Only print 64bit start_pfn_64, end_pfn_64 and max_mapnr_64
  debug messages for disk dump header version >= 6.
- Change type of bitmap_len in struct DumpInfo, from unsigned long to
  unsigned long long.
- Enhance bitmap writting function in reassemble_kdump_header().
  Prevent bitmap writting failure if the size of bitmap is too large to
  fit a sigle write.

v1:
- http://lists.infradead.org/pipermail/kexec/2013-September/009662.html


Signed-off-by: Jingbai Ma <jingbai.ma at hp.com>
Tested-by: Lisa Mitchell <lisa.mitchell at hp.com>
---
 IMPLEMENTATION |   17 +++++++-
 diskdump_mod.h |   17 +++++++-
 makedumpfile.c |  116 +++++++++++++++++++++++++++++++++++++++++---------------
 makedumpfile.h |    2 -
 4 files changed, 113 insertions(+), 39 deletions(-)

diff --git a/IMPLEMENTATION b/IMPLEMENTATION
index f0f3135..4feda02 100644
--- a/IMPLEMENTATION
+++ b/IMPLEMENTATION
@@ -48,7 +48,9 @@
                                                    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
@@ -69,14 +71,23 @@
         unsigned long   phys_base;
         int             dump_level;     /* header_version 1 and later */
 	int		split;		/* header_version 2 and later */
-	unsigned long	start_pfn;	/* header_version 2 and later */
-	unsigned long	end_pfn;	/* header_version 2 and later */
+	unsigned long	start_pfn;	/* header_version 2 and later,
+					   32bit only, full 64bit in
+					   start_pfn_64.
+					   Do not use this anymore! */
+	unsigned long	end_pfn;	/* header_version 2 and later,
+					   32bit only, full 64bit in
+					   end_pfn_64.
+					   Do not use this anymore! */
 	off_t		offset_vmcoreinfo;/* header_version 3 and later */
 	unsigned long	size_vmcoreinfo;  /* header_version 3 and later */
 	off_t		offset_note;      /* header_version 4 and later */
 	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 long start_pfn_64;  /* header_version 6 and later */
+	unsigned long long end_pfn_64;	  /* header_version 6 and later */
+	unsigned long long max_mapnr_64;  /* header_version 6 and later */
     };
 
   - 1st-bitmap
diff --git a/diskdump_mod.h b/diskdump_mod.h
index af060b6..d907775 100644
--- a/diskdump_mod.h
+++ b/diskdump_mod.h
@@ -48,7 +48,9 @@ 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
@@ -67,14 +69,23 @@ struct kdump_sub_header {
 	unsigned long	phys_base;
 	int		dump_level;	/* header_version 1 and later */
 	int		split;		/* header_version 2 and later */
-	unsigned long	start_pfn;	/* header_version 2 and later */
-	unsigned long	end_pfn;	/* header_version 2 and later */
+	unsigned long	start_pfn;	/* header_version 2 and later,
+					   32bit only, full 64bit in
+					   start_pfn_64.
+					   Do not use this anymore! */
+	unsigned long	end_pfn;	/* header_version 2 and later,
+					   32bit only, full 64bit in
+					   end_pfn_64.
+					   Do not use this anymore! */
 	off_t		offset_vmcoreinfo;/* header_version 3 and later */
 	unsigned long	size_vmcoreinfo;  /* header_version 3 and later */
 	off_t		offset_note;      /* header_version 4 and later */
 	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 long start_pfn_64;  /* header_version 6 and later */
+	unsigned long long end_pfn_64;	  /* header_version 6 and later */
+	unsigned long long max_mapnr_64;  /* header_version 6 and later */
 };
 
 /* page flags */
diff --git a/makedumpfile.c b/makedumpfile.c
index b42565c..3ac3ad0 100644
--- a/makedumpfile.c
+++ b/makedumpfile.c
@@ -23,6 +23,7 @@
 #include <stddef.h>
 #include <ctype.h>
 #include <sys/time.h>
+#include <limits.h>
 
 struct symbol_table	symbol_table;
 struct size_table	size_table;
@@ -125,7 +126,7 @@ get_max_mapnr(void)
 	unsigned long long max_paddr;
 
 	if (info->flag_refiltering) {
-		info->max_mapnr = info->dh_memory->max_mapnr;
+		info->max_mapnr = info->kh_memory->max_mapnr_64;
 		return TRUE;
 	}
 
@@ -783,6 +784,10 @@ get_kdump_compressed_header_info(char *filename)
 		ERRMSG("header does not have dump_level member\n");
 		return FALSE;
 	}
+
+	if (dh.header_version < 6)
+		kh.max_mapnr_64 = dh.max_mapnr;
+
 	DEBUG_MSG("diskdump main header\n");
 	DEBUG_MSG("  signature        : %s\n", dh.signature);
 	DEBUG_MSG("  header_version   : %d\n", dh.header_version);
@@ -790,7 +795,7 @@ get_kdump_compressed_header_info(char *filename)
 	DEBUG_MSG("  block_size       : %d\n", dh.block_size);
 	DEBUG_MSG("  sub_hdr_size     : %d\n", dh.sub_hdr_size);
 	DEBUG_MSG("  bitmap_blocks    : %d\n", dh.bitmap_blocks);
-	DEBUG_MSG("  max_mapnr        : 0x%x\n", dh.max_mapnr);
+	DEBUG_MSG("  max_mapnr(32bit) : 0x%x\n", dh.max_mapnr);
 	DEBUG_MSG("  total_ram_blocks : %d\n", dh.total_ram_blocks);
 	DEBUG_MSG("  device_blocks    : %d\n", dh.device_blocks);
 	DEBUG_MSG("  written_blocks   : %d\n", dh.written_blocks);
@@ -800,8 +805,14 @@ get_kdump_compressed_header_info(char *filename)
 	DEBUG_MSG("  phys_base        : 0x%lx\n", kh.phys_base);
 	DEBUG_MSG("  dump_level       : %d\n", kh.dump_level);
 	DEBUG_MSG("  split            : %d\n", kh.split);
-	DEBUG_MSG("  start_pfn        : 0x%lx\n", kh.start_pfn);
-	DEBUG_MSG("  end_pfn          : 0x%lx\n", kh.end_pfn);
+	DEBUG_MSG("  start_pfn(32bit) : 0x%lx\n", kh.start_pfn);
+	DEBUG_MSG("  end_pfn(32bit)   : 0x%lx\n", kh.end_pfn);
+	if (dh.header_version >= 6) {
+		/* A dumpfile contains full 64bit values. */
+		DEBUG_MSG("  start_pfn_64 : 0x%llx\n", kh.start_pfn_64);
+		DEBUG_MSG("  end_pfn_64 : 0x%llx\n", kh.end_pfn_64);
+		DEBUG_MSG("  max_mapnr_64 : 0x%llx\n", kh.max_mapnr_64);
+	}
 
 	info->dh_memory = malloc(sizeof(dh));
 	if (info->dh_memory == NULL) {
@@ -2766,14 +2777,16 @@ int
 initialize_bitmap_memory(void)
 {
 	struct disk_dump_header	*dh;
+	struct kdump_sub_header *kh;
 	struct dump_bitmap *bmp;
 	off_t bitmap_offset;
-	int bitmap_len, max_sect_len;
+	off_t bitmap_len, max_sect_len;
 	unsigned long pfn;
 	int i, j;
 	long block_size;
 
 	dh = info->dh_memory;
+	kh = info->kh_memory;
 	block_size = dh->block_size;
 
 	bitmap_offset
@@ -2793,7 +2806,7 @@ initialize_bitmap_memory(void)
 	bmp->offset = bitmap_offset + bitmap_len / 2;
 	info->bitmap_memory = bmp;
 
-	max_sect_len = divideup(dh->max_mapnr, BITMAP_SECT_LEN);
+	max_sect_len = divideup(kh->max_mapnr_64, BITMAP_SECT_LEN);
 	info->valid_pages = calloc(sizeof(ulong), max_sect_len);
 	if (info->valid_pages == NULL) {
 		ERRMSG("Can't allocate memory for the valid_pages. %s\n",
@@ -4705,7 +4718,7 @@ create_2nd_bitmap(void)
 int
 prepare_bitmap_buffer(void)
 {
-	unsigned long tmp;
+	unsigned long long tmp;
 
 	/*
 	 * Create 2 bitmaps (1st-bitmap & 2nd-bitmap) on block_size boundary.
@@ -4737,7 +4750,7 @@ prepare_bitmap_buffer(void)
 int
 prepare_bitmap_buffer_cyclic(void)
 {
-	unsigned long tmp;
+	unsigned long long tmp;
 
 	/*
 	 * Create 2 bitmaps (1st-bitmap & 2nd-bitmap) on block_size boundary.
@@ -5153,11 +5166,12 @@ write_kdump_header(void)
 	 * Write common header
 	 */
 	strncpy(dh->signature, KDUMP_SIGNATURE, strlen(KDUMP_SIGNATURE));
-	dh->header_version = 5;
+	dh->header_version = 6;
 	dh->block_size     = info->page_size;
 	dh->sub_hdr_size   = sizeof(kh) + size_note;
 	dh->sub_hdr_size   = divideup(dh->sub_hdr_size, dh->block_size);
-	dh->max_mapnr      = info->max_mapnr;
+	/* dh->max_mapnr may be truncated, full 64bit in kh.max_mapnr_64 */
+	dh->max_mapnr      = MIN(info->max_mapnr, UINT_MAX);
 	dh->nr_cpus        = get_nr_cpus();
 	dh->bitmap_blocks  = divideup(info->len_bitmap, dh->block_size);
 	memcpy(&dh->timestamp, &info->timestamp, sizeof(dh->timestamp));
@@ -5172,12 +5186,21 @@ write_kdump_header(void)
 	 */
 	size = sizeof(struct kdump_sub_header);
 	memset(&kh, 0, size);
+	/* 64bit max_mapnr_64 */
+	kh.max_mapnr_64 = info->max_mapnr;
 	kh.phys_base  = info->phys_base;
 	kh.dump_level = info->dump_level;
 	if (info->flag_split) {
 		kh.split = 1;
+		/* start_pfn and end_pfn may be truncated,
+		 * only for compatibility purpose
+		 */
 		kh.start_pfn = info->split_start_pfn;
 		kh.end_pfn   = info->split_end_pfn;
+
+		/* 64bit start_pfn_64 and end_pfn_64 */
+		kh.start_pfn_64 = info->split_start_pfn;
+		kh.end_pfn_64   = info->split_end_pfn;
 	}
 	if (has_pt_note()) {
 		/*
@@ -6421,7 +6444,7 @@ int
 write_kdump_bitmap(void)
 {
 	struct cache_data bm;
-	long buf_size;
+	long long buf_size;
 	off_t offset;
 
 	int ret = FALSE;
@@ -7796,10 +7819,8 @@ store_splitting_info(void)
 
 		if (i == 0) {
 			memcpy(&dh, &tmp_dh, sizeof(tmp_dh));
-			info->max_mapnr = dh.max_mapnr;
 			if (!set_page_size(dh.block_size))
 				return FALSE;
-			DEBUG_MSG("max_mapnr    : %llx\n", info->max_mapnr);
 			DEBUG_MSG("page_size    : %ld\n", info->page_size);
 		}
 
@@ -7816,11 +7837,26 @@ store_splitting_info(void)
 			return FALSE;
 
 		if (i == 0) {
+			if (dh.header_version >= 6)
+				info->max_mapnr = kh.max_mapnr_64;
+			else
+				info->max_mapnr = dh.max_mapnr;
+
+			DEBUG_MSG("max_mapnr    : %llx\n", info->max_mapnr);
+		}
+
+		if (i == 0) {
 			info->dump_level = kh.dump_level;
 			DEBUG_MSG("dump_level   : %d\n", info->dump_level);
 		}
-		SPLITTING_START_PFN(i) = kh.start_pfn;
-		SPLITTING_END_PFN(i)   = kh.end_pfn;
+
+		if (dh.header_version >= 6) {
+			SPLITTING_START_PFN(i) = kh.start_pfn_64;
+			SPLITTING_END_PFN(i)   = kh.end_pfn_64;
+		} else {
+			SPLITTING_START_PFN(i) = kh.start_pfn;
+			SPLITTING_END_PFN(i)   = kh.end_pfn;
+		}
 		SPLITTING_OFFSET_EI(i) = kh.offset_eraseinfo;
 		SPLITTING_SIZE_EI(i)   = kh.size_eraseinfo;
 	}
@@ -7954,6 +7990,7 @@ reassemble_kdump_header(void)
 	struct disk_dump_header dh;
 	struct kdump_sub_header kh;
 	char *buf_bitmap = NULL;
+	ssize_t status, read_size, written_size;
 
 	/*
 	 * Write common header.
@@ -7981,6 +8018,8 @@ reassemble_kdump_header(void)
 	kh.split = 0;
 	kh.start_pfn = 0;
 	kh.end_pfn   = 0;
+	kh.start_pfn_64 = 0;
+	kh.end_pfn_64 = 0;
 
 	if (lseek(info->fd_dumpfile, info->page_size, SEEK_SET) < 0) {
 		ERRMSG("Can't seek a file(%s). %s\n",
@@ -8030,36 +8069,49 @@ reassemble_kdump_header(void)
 		    SPLITTING_DUMPFILE(0), strerror(errno));
 		goto out;
 	}
-	if (read(fd, buf_bitmap, info->len_bitmap) != info->len_bitmap) {
-		ERRMSG("Can't read a file(%s). %s\n",
-		    SPLITTING_DUMPFILE(0), strerror(errno));
-		goto out;
+	read_size = 0;
+	while (read_size < info->len_bitmap) {
+		status = read(fd, buf_bitmap + read_size, info->len_bitmap
+			- read_size);
+		if (status < 0) {
+			ERRMSG("Can't read a file(%s). %s\n",
+				SPLITTING_DUMPFILE(0), strerror(errno));
+			goto out;
+		}
+		read_size += status;
 	}
-
 	if (lseek(info->fd_dumpfile, offset, SEEK_SET) < 0) {
 		ERRMSG("Can't seek a file(%s). %s\n",
 		    info->name_dumpfile, strerror(errno));
 		goto out;
 	}
-	if (write(info->fd_dumpfile, buf_bitmap, info->len_bitmap)
-	    != info->len_bitmap) {
-		ERRMSG("Can't write a file(%s). %s\n",
-		    info->name_dumpfile, strerror(errno));
-		goto out;
+	written_size = 0;
+	while (written_size < info->len_bitmap) {
+		status = write(info->fd_dumpfile, buf_bitmap + written_size,
+			info->len_bitmap - written_size);
+		if (status < 0) {
+			ERRMSG("Can't write a file(%s). %s\n",
+			    info->name_dumpfile, strerror(errno));
+			goto out;
+		}
+		written_size += status;
 	}
-
 	if (lseek(info->fd_bitmap, 0x0, SEEK_SET) < 0) {
 		ERRMSG("Can't seek a file(%s). %s\n",
 		    info->name_bitmap, strerror(errno));
 		goto out;
 	}
-	if (write(info->fd_bitmap, buf_bitmap, info->len_bitmap)
-	    != info->len_bitmap) {
-		ERRMSG("Can't write a file(%s). %s\n",
-		    info->name_bitmap, strerror(errno));
-		goto out;
+	written_size = 0;
+	while (written_size < info->len_bitmap) {
+		status = write(info->fd_bitmap, buf_bitmap + written_size,
+			info->len_bitmap - written_size);
+		if (status < 0) {
+			ERRMSG("Can't write a file(%s). %s\n",
+			    info->name_bitmap, strerror(errno));
+			goto out;
+		}
+		written_size += status;
 	}
-
 	ret = TRUE;
 out:
 	if (fd > 0)
diff --git a/makedumpfile.h b/makedumpfile.h
index a5826e0..4056fa0 100644
--- a/makedumpfile.h
+++ b/makedumpfile.h
@@ -927,7 +927,7 @@ struct DumpInfo {
 	 */
 	int		block_order;
 	off_t		offset_bitmap1;
-	unsigned long	len_bitmap;          /* size of bitmap(1st and 2nd) */
+	unsigned long long	len_bitmap; /* size of bitmap(1st and 2nd) */
 	struct dump_bitmap 		*bitmap1;
 	struct dump_bitmap 		*bitmap2;
 	struct disk_dump_header		*dump_header;




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