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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH] fix read size in xendump.c
Hi. Recently I twisted the xen xm dump-core format so that the section order was changed for optimization. Although it shouldn't affect analysis tools, it revealed a bug. The crash utility tries to read the file beyond EOF. So far it wasn't issue because of section ordering. This patch fixes it by calculating read size correctly Dave, Although I don't think that it causes serious issues, Could you check whether the minor update of the format affects the crash utility? http://article.gmane.org/gmane.comp.emulators.xen.ia64/7531 http://article.gmane.org/gmane.comp.emulators.xen.devel/42996 --- crash-4.0-4.6-ORIG/xendump.c 2007-08-28 00:51:11.000000000 +0900 +++ ./crash-4.0-4.6/xendump.c 2007-08-29 18:14:05.000000000 +0900 @@ -1289,9 +1289,8 @@ xc_core_mfn_to_page(ulong mfn, char *pgb for (b = 0, idx = -1, done = FALSE; !done && (b < nr_pages); b += MAX_BATCH_SIZE) { - - if (read(xd->xfd, tmp, sizeof(ulong) * MAX_BATCH_SIZE) != - (MAX_BATCH_SIZE * sizeof(ulong))) { + size_t size = sizeof(ulong) * MIN(MAX_BATCH_SIZE, nr_pages - b); + if (read(xd->xfd, tmp, size) != size) { error(INFO, "cannot read index page %d\n", b); return NULL; } @@ -1348,13 +1347,11 @@ xc_core_elf_mfn_to_page(ulong mfn, char { int i, b, idx, done; off_t offset; - size_t size; uint nr_pages; ulong tmp; struct xen_dumpcore_p2m p2m_batch[MAX_BATCH_SIZE]; offset = xd->xc_core.header.xch_index_offset; - size = sizeof(struct xen_dumpcore_p2m) * MAX_BATCH_SIZE; nr_pages = xd->xc_core.header.xch_nr_pages; if (lseek(xd->xfd, offset, SEEK_SET) == -1) @@ -1362,7 +1359,8 @@ xc_core_elf_mfn_to_page(ulong mfn, char for (b = 0, idx = -1, done = FALSE; !done && (b < nr_pages); b += MAX_BATCH_SIZE) { - + size_t size = sizeof(struct xen_dumpcore_p2m) * + MIN(MAX_BATCH_SIZE, nr_pages - b); if (read(xd->xfd, &p2m_batch[0], size) != size) { error(INFO, "cannot read index page %d\n", b); return NULL; @@ -1437,9 +1435,9 @@ xc_core_mfn_to_page_index(ulong mfn) nr_pages *= 2; for (b = 0; b < nr_pages; b += MAX_BATCH_SIZE) { - - if (read(xd->xfd, tmp, sizeof(ulong) * MAX_BATCH_SIZE) != - (MAX_BATCH_SIZE * sizeof(ulong))) { + size_t size = + sizeof(ulong) * MIN(MAX_BATCH_SIZE, nr_pages - b); + if (read(xd->xfd, tmp, size) != size) { error(INFO, "cannot read index page %d\n", b); return MFN_NOT_FOUND; } @@ -1469,20 +1467,19 @@ xc_core_elf_mfn_to_page_index(ulong mfn) { int i, b; off_t offset; - size_t size; uint nr_pages; ulong tmp; struct xen_dumpcore_p2m p2m_batch[MAX_BATCH_SIZE]; offset = xd->xc_core.header.xch_index_offset; - size = sizeof(struct xen_dumpcore_p2m) * MAX_BATCH_SIZE; nr_pages = xd->xc_core.header.xch_nr_pages; if (lseek(xd->xfd, offset, SEEK_SET) == -1) error(FATAL, "cannot lseek to page index\n"); for (b = 0; b < nr_pages; b += MAX_BATCH_SIZE) { - + size_t size = sizeof(struct xen_dumpcore_p2m) * + MIN(MAX_BATCH_SIZE, nr_pages - b); if (read(xd->xfd, &p2m_batch[0], size) != size) { error(INFO, "cannot read index page %d\n", b); return MFN_NOT_FOUND; @@ -1563,8 +1560,9 @@ check_next_4: nr_pages = xd->xc_core.header.xch_nr_pages; for (b = 0; b < nr_pages; b += MAX_BATCH_SIZE) { - if (read(xd->xfd, tmp, sizeof(ulong) * MAX_BATCH_SIZE) != - (MAX_BATCH_SIZE * sizeof(ulong))) { + size_t size = sizeof(ulong) * + MIN(MAX_BATCH_SIZE, nr_pages - b); + if (read(xd->xfd, tmp, size) != size) { error(INFO, "cannot read index page %d\n", b); return FALSE; } @@ -1595,8 +1593,9 @@ show_64bit_mfns: nr_pages = xd->xc_core.header.xch_nr_pages; for (b = 0; b < nr_pages; b += MAX_BATCH_SIZE) { - if (read(xd->xfd, tmp64, sizeof(ulonglong) * MAX_BATCH_SIZE) != - (MAX_BATCH_SIZE * sizeof(ulonglong))) { + size_t size = sizeof(ulonglong) * + MIN(MAX_BATCH_SIZE, nr_pages - b); + if (read(xd->xfd, tmp64, size) != size) { error(INFO, "cannot read index page %d\n", b); return FALSE; } @@ -1709,13 +1708,11 @@ xc_core_elf_pfn_to_page_index(ulong pfn) { int i, b, start_index; off_t offset; - size_t size; uint nr_pages; ulong tmp; struct xen_dumpcore_p2m p2m_batch[MAX_BATCH_SIZE]; offset = xd->xc_core.header.xch_index_offset; - size = sizeof(struct xen_dumpcore_p2m) * MAX_BATCH_SIZE; nr_pages = xd->xc_core.header.xch_nr_pages; /* @@ -1744,7 +1741,8 @@ xc_core_elf_pfn_to_page_index(ulong pfn) error(FATAL, "cannot lseek to page index\n"); for (b = start_index; b < nr_pages; b += MAX_BATCH_SIZE) { - + size_t size = sizeof(struct xen_dumpcore_p2m) * + MIN(MAX_BATCH_SIZE, nr_pages - b); if (read(xd->xfd, &p2m_batch[0], size) != size) { error(INFO, "cannot read index page %d\n", b); return PFN_NOT_FOUND; @@ -1838,13 +1836,11 @@ xc_core_elf_pfn_valid(ulong pfn) { int i, b, start_index; off_t offset; - size_t size; uint nr_pages; ulong tmp; uint64_t pfn_batch[MAX_BATCH_SIZE]; offset = xd->xc_core.header.xch_index_offset; - size = sizeof(uint64_t) * MAX_BATCH_SIZE; nr_pages = xd->xc_core.header.xch_nr_pages; /* @@ -1873,7 +1869,8 @@ xc_core_elf_pfn_valid(ulong pfn) error(FATAL, "cannot lseek to page index\n"); for (b = start_index; b < nr_pages; b += MAX_BATCH_SIZE) { - + size_t size = sizeof(uint64_t) * + MIN(MAX_BATCH_SIZE, nr_pages - b); if (read(xd->xfd, &pfn_batch[0], size) != size) { error(INFO, "cannot read index page %d\n", b); return PFN_NOT_FOUND; -- yamahata _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxxxxxxxx http://lists.xensource.com/xen-devel
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