[PATCH v3] crash utility: fix max_mapnr issue on system has over 44-bit addressing
Dave Anderson
anderson at redhat.com
Tue Oct 15 15:22:55 EDT 2013
Hello Jingbai,
I have a few additional comments below:
----- Original Message -----
> 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 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 corresponding patch for makedumpfile can be found here:
> http://lists.infradead.org/pipermail/kexec/2013-October/009727.html
>
> Changelog:
> v3:
> - Fix a bug that failed to work with old split format kdumps.
>
> 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.
> - Add a 64bit max_mapnr in struct diskdump_data. The max_mapnr_64 in
> the sub-header only exists in compressed kdump file format, so can't
> be used in diskdump file format.
> - Merge a patch from Dave Anderson that fixed bitmap_len issue.
>
> v1:
> - http://lists.infradead.org/pipermail/kexec/2013-September/009663.html
>
> Signed-off-by: Jingbai Ma <jingbai.ma at hp.com>
> Tested-by: Lisa Mitchell <lisa.mitchell at hp.com>
> ---
> diskdump.c | 122
> ++++++++++++++++++++++++++++++++++++++++++++++++------------
> diskdump.h | 17 +++++++-
> 2 files changed, 112 insertions(+), 27 deletions(-)
>
> diff --git a/diskdump.c b/diskdump.c
> index 0819a3f..bb7a33e 100644
> --- a/diskdump.c
> +++ b/diskdump.c
> @@ -40,11 +40,13 @@ struct diskdump_data {
> struct disk_dump_sub_header *sub_header;
> struct kdump_sub_header *sub_header_kdump;
>
> + unsigned long long max_mapnr; /* 64bit max_mapnr */
> +
> size_t data_offset;
> int block_size;
> int block_shift;
> char *bitmap;
> - int bitmap_len;
> + off_t bitmap_len;
> char *dumpable_bitmap;
> int byte, bit;
> char *compressed_page; /* copy of compressed page data */
> @@ -170,9 +172,9 @@ add_diskdump_data(char* name)
> dd->filename = name;
>
> if (CRASHDEBUG(1))
> - fprintf(fp, "%s: start_pfn=%lu, end_pfn=%lu\n", name,
> - dd->sub_header_kdump->start_pfn,
> - dd->sub_header_kdump->end_pfn);
> + fprintf(fp, "%s: start_pfn=%llu, end_pfn=%llu\n", name,
> + dd->sub_header_kdump->start_pfn_64,
> + dd->sub_header_kdump->end_pfn_64);
> }
>
> static void
> @@ -199,13 +201,13 @@ 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));
> }
> @@ -214,7 +216,7 @@ static inline int
> dump_is_partial(const struct disk_dump_header *header)
> {
> return header->bitmap_blocks >=
> - divideup(divideup(header->max_mapnr, 8), dd->block_size) * 2;
> + divideup(divideup(dd->max_mapnr, 8), dd->block_size) * 2;
> }
>
> static int
> @@ -321,6 +323,9 @@ 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 long start_pfn_64; / header_version 6 and later
> /
> + * [64] unsigned long long end_pfn_64; / header_version 6 and later
> /
> + * [72] unsigned long long max_mapnr_64; / header_version 6 and later
> /
> * };
> *
> * But when compiled on an ARM processor, each 64-bit "off_t" would be
> pushed
> @@ -337,7 +342,10 @@ x86_process_elf_notes(void *note_ptr, unsigned long
> size_note)
> * [40] off_t offset_note; / header_version 4 and later
> /
> * [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
> /
> + * [64] unsigned long size_eraseinfo; / header_version 5 and later
> /
> + * [72] unsigned long long start_pfn_64; / header_version 6 and later
> /
> + * [80] unsigned long long end_pfn_64; / header_version 6 and later
> /
> + * [88] unsigned long long max_mapnr_64; / header_version 6 and later
> /
> * };
> *
> */
> @@ -357,6 +365,10 @@ 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 */
> + int pad4;
> + 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 */
> };
>
> static void
> @@ -380,6 +392,15 @@ 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->start_pfn_64 = kdsh_ARM_target->start_pfn_64;
> + kdsh->end_pfn_64 = kdsh_ARM_target->end_pfn_64;
> + kdsh->max_mapnr_64 = kdsh_ARM_target->map_mapnr_64;
> + } else {
> + kdsh->start_pfn_64 = kdsh_ARM_target->start_pfn;
> + kdsh->end_pfn_64 = kdsh_ARM_target->end_pfn;
> + kdsh->max_mapnr_64 = dd->map_mapnr;
> + }
> }
> #endif /* __i386__ && ARM */
>
> @@ -390,7 +411,10 @@ read_dump_header(char *file)
> struct disk_dump_sub_header *sub_header = NULL;
> struct kdump_sub_header *sub_header_kdump = NULL;
> size_t size;
> - int bitmap_len;
> + off_t bitmap_len;
> + char *bufptr;
> + size_t len;
> + size_t bytes_read;
> int block_size = (int)sysconf(_SC_PAGESIZE);
> off_t offset;
> const off_t failed = (off_t)-1;
> @@ -540,8 +564,27 @@ restart:
> #if defined(__i386__) && defined(ARM)
> arm_kdump_header_adjust(header->header_version);
> #endif
> + /* use 64bit max_mapnr in compressed kdump file sub-header */
> + if (header->header_version >= 6)
> + dd->max_mapnr = dd->sub_header_kdump->max_mapnr_64;
> + else {
> + dd->sub_header_kdump->start_pfn_64
> + = dd->sub_header_kdump->start_pfn;
> + dd->sub_header_kdump->end_pfn_64
> + = dd->sub_header_kdump->end_pfn;
> + }
> + } else {
> + /* the 64bit max_mapnr only exists in sub-header of compressed
> + * kdump file, if it's not a compressed kdump file, we have to
> + * use the old 32bit max_mapnr in dumpfile header.
> + * max_mapnr may be truncated here.
> + */
> + dd->max_mapnr = header->max_mapnr;
> }
The additional "} else {" segment above doesn't make sense because either
DISKDUMP_VALID() or KDUMP_CMPRS_VALID() are true, so the "else" part will
never be executed.
The patch works because you follow the above section with this piece:
> + if (header->header_version < 6)
> + dd->max_mapnr = header->max_mapnr;
> +
> /* read memory bitmap */
> bitmap_len = block_size * header->bitmap_blocks;
> dd->bitmap_len = bitmap_len;
> @@ -571,11 +614,27 @@ restart:
> DISKDUMP_VALID() ? "diskdump" : "compressed kdump");
> goto err;
> }
> +#ifdef OLDWAY
> if (read(dd->dfd, dd->bitmap, bitmap_len) < bitmap_len) {
> error(INFO, "%s: cannot read memory bitmap\n",
> DISKDUMP_VALID() ? "diskdump" : "compressed kdump");
> goto err;
> }
> +#else
> + bufptr = dd->bitmap;
> + len = bitmap_len;
> + while (len) {
> + bytes_read = read(dd->dfd, bufptr, len);
> + if (bytes_read < 0) {
> + error(INFO, "%s: cannot read memory bitmap\n",
> + DISKDUMP_VALID() ? "diskdump"
> + : "compressed kdump");
> + goto err;
> + }
> + len -= bytes_read;
> + bufptr += bytes_read;
> + }
> +#endif
You can get rid of the "#ifdef OLDWAY" section -- I left that there when
I gave Lisa my debug version of the function so that the difference would
be obvious.
> }
>
> if (dump_is_partial(header))
> @@ -679,13 +738,13 @@ restart:
> }
>
> if (!is_split) {
> - max_sect_len = divideup(header->max_mapnr, BITMAP_SECT_LEN);
> + max_sect_len = divideup(dd->max_mapnr, BITMAP_SECT_LEN);
> pfn = 0;
> dd->filename = file;
> }
> else {
> - ulong start = sub_header_kdump->start_pfn;
> - ulong end = sub_header_kdump->end_pfn;
> + unsigned long long start = sub_header_kdump->start_pfn_64;
> + unsigned long long end = sub_header_kdump->end_pfn_64;
> max_sect_len = divideup(end - start + 1, BITMAP_SECT_LEN);
> pfn = start;
> }
> @@ -727,8 +786,9 @@ pfn_to_pos(ulong pfn)
> ulong p1, p2;
>
> if (KDUMP_SPLIT()) {
> - p1 = pfn - dd->sub_header_kdump->start_pfn;
> - p2 = round(p1, BITMAP_SECT_LEN) + dd->sub_header_kdump->start_pfn;
> + p1 = pfn - dd->sub_header_kdump->start_pfn_64;
> + p2 = round(p1, BITMAP_SECT_LEN)
> + + dd->sub_header_kdump->start_pfn_64;
> }
> else {
> p1 = pfn;
> @@ -1034,12 +1094,12 @@ read_diskdump(int fd, void *bufptr, int cnt, ulong
> addr, physaddr_t paddr)
> if (KDUMP_SPLIT()) {
> /* Find proper dd */
> int i;
> - unsigned long start_pfn;
> - unsigned long end_pfn;
> + unsigned long long start_pfn;
> + unsigned long long end_pfn;
>
> for (i=0; i<num_dumpfiles; i++) {
> - start_pfn = dd_list[i]->sub_header_kdump->start_pfn;
> - end_pfn = dd_list[i]->sub_header_kdump->end_pfn;
> + start_pfn = dd_list[i]->sub_header_kdump->start_pfn_64;
> + end_pfn = dd_list[i]->sub_header_kdump->end_pfn_64;
> if ((pfn >= start_pfn) && (pfn <= end_pfn)) {
> dd = dd_list[i];
> break;
> @@ -1058,14 +1118,14 @@ 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->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->max_mapnr)
> + fprintf(fp, "max_mapnr: %llx\n",
> + dd->max_mapnr);
> else
> fprintf(fp, "!page_is_ram\n");
> }
> @@ -1517,7 +1577,7 @@ __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);
> + fprintf(fp, " max_mapnr: %llu\n", dd->max_mapnr);
Please display the original dh->max_mapnr as it exists in the dumpfile
header, regardless whether it is the obsolete version or not.
Your new "dd->max_mapnr" should be displayed further down in the function
where the other diskdump_data fields are shown.
> 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);
> @@ -1662,6 +1722,20 @@ __diskdump_memory_dump(FILE *fp)
> dump_eraseinfo(fp);
> }
> }
> + if (dh->header_version >= 6) {
> + fprintf(fp, " start_pfn_64: ");
> + if (KDUMP_SPLIT())
> + fprintf(fp, "%lld (0x%llx)\n",
> + kdsh->start_pfn_64, kdsh->start_pfn_64);
> + else
> + fprintf(fp, "(unused)\n");
> + fprintf(fp, " end_pfn_64: ");
> + if (KDUMP_SPLIT())
> + fprintf(fp, "%lld (0x%llx)\n",
> + kdsh->end_pfn_64, kdsh->end_pfn_64);
> + else
> + fprintf(fp, "(unused)\n");
> + }
> fprintf(fp, "\n");
> } else
> fprintf(fp, "(n/a)\n\n");
> @@ -1670,7 +1744,7 @@ __diskdump_memory_dump(FILE *fp)
> fprintf(fp, " block_size: %d\n", dd->block_size);
> fprintf(fp, " block_shift: %d\n", dd->block_shift);
> fprintf(fp, " bitmap: %lx\n", (ulong)dd->bitmap);
> - fprintf(fp, " bitmap_len: %d\n", dd->bitmap_len);
> + fprintf(fp, " bitmap_len: %ld\n", dd->bitmap_len);
> fprintf(fp, " dumpable_bitmap: %lx\n", (ulong)dd->dumpable_bitmap);
> fprintf(fp, " byte: %d\n", dd->byte);
> fprintf(fp, " bit: %d\n", dd->bit);
> diff --git a/diskdump.h b/diskdump.h
> index 9ab10b6..0492351 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! */
You can change this comment to read "obsolete" so that it is similar to Daisuke's
suggestion for makedumpfile.
> unsigned int total_ram_blocks;/* Number of blocks should be
> written */
> unsigned int device_blocks; /* Number of total blocks in
> @@ -61,14 +63,23 @@ 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.
Same here...
> + 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 */
Thanks,
Dave
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