The mkl_memory_patched.o object inside the libmkl_core.a library from
the Intel Math Kernel Library version 2018.2.199 has this section
with an alignment of 4096 and offset of 0xb68:
[ 2] .data PROGBITS
0000000000000000 000b68 011000 00 WA 0 0 4096
Reading this file with libelf and trying to write it back to disk triggers
the following sequence of events:
1) code in elf_getdata.c clamps d_align for this section's data buffer
to the section's offset
2) code in elf32_updatenull.c checks if the alignment is a power of two
and incorrectly returns an error
This commit fixes this corner case by increasing the alignment to the
next power of two after the clamping, so the check passes.
A test that reproduces this bug using strip is also included.
Signed-off-by: Andrei Homescu <ah@immunant.com>
+2021-06-09 Andrei Homescu <ah@immunant.com>
+
+ * elf_getdata.c: Fix d_align for sections where alignment is larger
+ than offset.
+
2020-12-12 Mark Wielaard <mark@klomp.org>
* elf.h: Update from glibc.
which should be uncommon. */
align = align ?: 1;
if (type != SHT_NOBITS && align > offset)
- align = offset;
+ {
+ /* Align the offset to the next power of two. Uses algorithm from
+ https://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2 */
+ align = offset - 1;
+ align |= align >> 1;
+ align |= align >> 2;
+ align |= align >> 4;
+ align |= align >> 8;
+ align |= align >> 16;
+ align |= align >> 32;
+ align++;
+ }
scn->rawdata.d.d_align = align;
if (elf->class == ELFCLASS32
|| (offsetof (struct Elf, state.elf32.ehdr)
+2021-06-09 Andrei Homescu <ah@immunant.com>
+
+ * testfile-largealign.o.bz2: New test file.
+ * run-strip-largealign.sh: New test.
+ * Makefile.am (TESTS): Add run-strip-largealign.sh.
+ (EXTRA_DIST): Add run-strip-largealign.sh and
+ testfile-largealign.o.bz2
+
2021-07-02 Mark Wielaard <mark@klomp.org>
- * run-debuginfo-find.sh: unset VALGRIND_CMD before testing debuginfod
- client cache.
+ * run-debuginfo-find.sh: unset VALGRIND_CMD before testing debuginfod
+ client cache.
2021-06-16 Frank Ch. Eigler <fche@redhat.com>
leb128 read_unaligned \
msg_tst system-elf-libelf-test \
$(asm_TESTS) run-disasm-bpf.sh run-low_high_pc-dw-form-indirect.sh \
- run-readelf-dw-form-indirect.sh
+ run-readelf-dw-form-indirect.sh run-strip-largealign.sh
if !BIARCH
export ELFUTILS_DISABLE_BIARCH = 1
testfile_pt_gnu_prop.bz2 testfile_pt_gnu_prop32.bz2 \
run-getphdrnum.sh testfile-phdrs.elf.bz2 \
run-test-includes.sh run-low_high_pc-dw-form-indirect.sh \
- run-readelf-dw-form-indirect.sh testfile-dw-form-indirect.bz2
+ run-readelf-dw-form-indirect.sh testfile-dw-form-indirect.bz2 \
+ testfile-largealign.bz2 run-strip-largealign.sh
if USE_VALGRIND
--- /dev/null
+#! /bin/sh
+# Copyright (C) 2021 Runsafe Security, Inc.
+# This file is part of elfutils.
+#
+# This file is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# elfutils is distributed in the hope that it will be useful, but
+# WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+
+. $srcdir/test-subr.sh
+
+# = testfile-largealign.S =
+# section .data
+# align 4096
+# dd 0x12345678
+#
+# nasm -f elf64 -o testfile-largealign.o testfile-largealign.S
+
+infile=testfile-largealign.o
+outfile=$infile.stripped
+
+testfiles $infile
+tempfiles $outfile
+
+testrun ${abs_top_builddir}/src/strip -o $outfile $infile
+testrun ${abs_top_builddir}/src/elflint --gnu $outfile