Date: Tue, 03 Sep 2019 14:07:42 -0000 From: Ed Maste <emaste@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r346582 - head/usr.bin/ar Message-ID: <201904221955.x3MJtmAm016884@repo.freebsd.org>
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Author: emaste Date: Mon Apr 22 19:55:47 2019 New Revision: 346582 URL: https://svnweb.freebsd.org/changeset/base/346582 Log: ar: shuffle symbol offsets during conversion for 32-bit ar archives During processing we maintain symbol offsets in the 64-bit s_so array, and when writing the archive convert to 32-bit if no offsets are greater than 4GB. However, this was somewhat inefficient as we looped over the array twice: first, converting to big endian and second, writing each 32-bit value one at a time (and incorrectly so on big-endian platforms). Instead, when writing a 32-bit archive shuffle convert symbol data to big endian (as required by the ar format) and shuffle to the beginning of the allocation at the same time. Also correct emission of the symbol count on big endian platforms. Further changes are planned, but this should fix powerpc64. Reported by: jhibbits, mlinimon Reviewed by: jhibbits, Gerald Aryeetey (earlier) Tested by: jhibbits MFC after: 10 days MFC with: r346079 Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D20007 Modified: head/usr.bin/ar/write.c Modified: head/usr.bin/ar/write.c ============================================================================== --- head/usr.bin/ar/write.c Mon Apr 22 19:36:19 2019 (r346581) +++ head/usr.bin/ar/write.c Mon Apr 22 19:55:47 2019 (r346582) @@ -616,6 +616,7 @@ write_objs(struct bsdar *bsdar) size_t pm_sz; /* size of pseudo members */ size_t w_sz; /* size of words in symbol table */ uint64_t nr; + uint32_t nr32; int i; if (elf_version(EV_CURRENT) == EV_NONE) @@ -669,15 +670,18 @@ write_objs(struct bsdar *bsdar) s_sz = (bsdar->s_cnt + 1) * sizeof(uint64_t) + bsdar->s_sn_sz; pm_sz += s_sz; - } - - for (i = 0; (size_t)i < bsdar->s_cnt; i++) { - if (w_sz == sizeof(uint32_t)) + /* Convert to big-endian. */ + for (i = 0; (size_t)i < bsdar->s_cnt; i++) bsdar->s_so[i] = - htobe32(bsdar->s_so[i] + pm_sz); - else - bsdar->s_so[i] = htobe64(bsdar->s_so[i] + pm_sz); + } else { + /* + * Convert to big-endian and shuffle in-place to + * the front of the allocation. XXX UB + */ + for (i = 0; (size_t)i < bsdar->s_cnt; i++) + ((uint32_t *)(bsdar->s_so))[i] = + htobe32(bsdar->s_so[i] + pm_sz); } } @@ -708,19 +712,14 @@ write_objs(struct bsdar *bsdar) archive_entry_set_size(entry, (bsdar->s_cnt + 1) * w_sz + bsdar->s_sn_sz); AC(archive_write_header(a, entry)); - if (w_sz == sizeof(uint32_t)) - nr = (uint64_t)htobe32((uint32_t)bsdar->s_cnt); - else + if (w_sz == sizeof(uint64_t)) { nr = htobe64(bsdar->s_cnt); - write_data(bsdar, a, &nr, w_sz); - if (w_sz == sizeof(uint64_t)) - write_data(bsdar, a, bsdar->s_so, sizeof(uint64_t) * - bsdar->s_cnt); - else - for (i = 0; (size_t)i < bsdar->s_cnt; i++) - write_data(bsdar, a, - (uint32_t *)&bsdar->s_so[i], - sizeof(uint32_t)); + write_data(bsdar, a, &nr, sizeof(nr)); + } else { + nr32 = htobe32((uint32_t)bsdar->s_cnt); + write_data(bsdar, a, &nr32, sizeof(nr32)); + } + write_data(bsdar, a, bsdar->s_so, w_sz * bsdar->s_cnt); write_data(bsdar, a, bsdar->s_sn, bsdar->s_sn_sz); archive_entry_free(entry); }
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