Re: [Crash-utility] [PATCH v3] crash utility: fix max_mapnr issue on system has over 44-bit addressing

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&lt;jingbai.ma(a)hp.com&gt; > Tested-by: Lisa Mitchell&lt;lisa.mitchell(a)hp.com&gt; > --- > 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