From: Jan Kratochvil Date: Thu, 26 Feb 2015 13:08:01 +0000 (+0100) Subject: SEGV in ppc64_elf_get_synthetic_symtab reading a separate debug file X-Git-Tag: gdb-7.10-release~1492 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=80c570537e380c1b8e48754c0ddbce2abcde2d00;p=platform%2Fupstream%2Fbinutils.git SEGV in ppc64_elf_get_synthetic_symtab reading a separate debug file The attached patch fixes the SEGV and lets GDB successfully load all kernel modules installed by default on RHEL 7. Valgrind on F-21 x86_64 host has shown me more clear what is the problem: Reading symbols from /home/jkratoch/t/cordic.ko...Reading symbols from /home/jkratoch/t/cordic.ko.debug...================================================================= ==22763==ERROR: AddressSanitizer: heap-use-after-free on address 0x6120000461c8 at pc 0x150cdbd bp 0x7fffffffc7e0 sp 0x7fffffffc7d0 READ of size 8 at 0x6120000461c8 thread T0 #0 0x150cdbc in ppc64_elf_get_synthetic_symtab /home/jkratoch/redhat/gdb-test-asan/bfd/elf64-ppc.c:3282 #1 0x8c5274 in elf_read_minimal_symbols /home/jkratoch/redhat/gdb-test-asan/gdb/elfread.c:1205 #2 0x8c55e7 in elf_symfile_read /home/jkratoch/redhat/gdb-test-asan/gdb/elfread.c:1268 [...] 0x6120000461c8 is located 264 bytes inside of 288-byte region [0x6120000460c0,0x6120000461e0) freed by thread T0 here: #0 0x7ffff715454f in __interceptor_free (/lib64/libasan.so.1+0x5754f) #1 0xde9cde in xfree common/common-utils.c:98 #2 0x9a04f7 in do_my_cleanups common/cleanups.c:155 #3 0x9a05d3 in do_cleanups common/cleanups.c:177 #4 0x8c538a in elf_read_minimal_symbols /home/jkratoch/redhat/gdb-test-asan/gdb/elfread.c:1229 #5 0x8c55e7 in elf_symfile_read /home/jkratoch/redhat/gdb-test-asan/gdb/elfread.c:1268 [...] previously allocated by thread T0 here: #0 0x7ffff71547c7 in malloc (/lib64/libasan.so.1+0x577c7) #1 0xde9b95 in xmalloc common/common-utils.c:41 #2 0x8c4da2 in elf_read_minimal_symbols /home/jkratoch/redhat/gdb-test-asan/gdb/elfread.c:1147 #3 0x8c55e7 in elf_symfile_read /home/jkratoch/redhat/gdb-test-asan/gdb/elfread.c:1268 [...] SUMMARY: AddressSanitizer: heap-use-after-free /home/jkratoch/redhat/gdb-test-asan/bfd/elf64-ppc.c:3282 ppc64_elf_get_synthetic_symtab [...] ==22763==ABORTING A similar case a few lines later I have fixed in 2010 by: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=3f1eff0a2c7f0e7078f011f55b8e7f710aae0cc2 My testcase does not always reproduce it but at least a bit: * GDB without ppc64 target (even as a secondary one) is reported as "untested" * ASAN-built GDB with ppc64 target always crashes (and PASSes with this fix) * unpatched non-ASAN-built GDB with ppc64 target crashes from commandline * unpatched non-ASAN-built GDB with ppc64 target PASSes from runtest (?) gdb/ChangeLog 2015-02-26 Jan Kratochvil * elfread.c (elf_read_minimal_symbols): Use bfd_alloc for bfd_canonicalize_symtab. gdb/testsuite/ChangeLog 2015-02-26 Jan Kratochvil * gdb.arch/cordic.ko.bz2: New file. * gdb.arch/cordic.ko.debug.bz2: New file. * gdb.arch/ppc64-symtab-cordic.exp: New file. --- diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 9934346..2a2dadd 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2015-02-26 Jan Kratochvil + + * elfread.c (elf_read_minimal_symbols): Use bfd_alloc for + bfd_canonicalize_symtab. + 2015-02-25 John Baldwin * amd64fbsd-nat.c: Include sys/user.h. diff --git a/gdb/elfread.c b/gdb/elfread.c index 65c63f0..4a6576f 100644 --- a/gdb/elfread.c +++ b/gdb/elfread.c @@ -1144,8 +1144,10 @@ elf_read_minimal_symbols (struct objfile *objfile, int symfile_flags, if (storage_needed > 0) { - symbol_table = (asymbol **) xmalloc (storage_needed); - make_cleanup (xfree, symbol_table); + /* Memory gets permanently referenced from ABFD after + bfd_canonicalize_symtab so it must not get freed before ABFD gets. */ + + symbol_table = bfd_alloc (abfd, storage_needed); symcount = bfd_canonicalize_symtab (objfile->obfd, symbol_table); if (symcount < 0) diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index c7b1c15..504e2f0 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,9 @@ +2015-02-26 Jan Kratochvil + + * gdb.arch/cordic.ko.bz2: New file. + * gdb.arch/cordic.ko.debug.bz2: New file. + * gdb.arch/ppc64-symtab-cordic.exp: New file. + 2015-02-25 Yao Qi * gdb.xml/tdesc-regs.exp: Set core-regs to aarch64-core.xml for diff --git a/gdb/testsuite/gdb.arch/cordic.ko.bz2 b/gdb/testsuite/gdb.arch/cordic.ko.bz2 new file mode 100644 index 0000000..8cb5d66 Binary files /dev/null and b/gdb/testsuite/gdb.arch/cordic.ko.bz2 differ diff --git a/gdb/testsuite/gdb.arch/cordic.ko.debug.bz2 b/gdb/testsuite/gdb.arch/cordic.ko.debug.bz2 new file mode 100644 index 0000000..8685f82 Binary files /dev/null and b/gdb/testsuite/gdb.arch/cordic.ko.debug.bz2 differ diff --git a/gdb/testsuite/gdb.arch/ppc64-symtab-cordic.exp b/gdb/testsuite/gdb.arch/ppc64-symtab-cordic.exp new file mode 100644 index 0000000..d9a3f13 --- /dev/null +++ b/gdb/testsuite/gdb.arch/ppc64-symtab-cordic.exp @@ -0,0 +1,51 @@ +# Copyright 2015 Free Software Foundation, Inc. + +# This program 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. +# +# This program 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 . + +standard_testfile + +set kobz2file ${srcdir}/${subdir}/cordic.ko.bz2 +set kofile ${objdir}/${subdir}/cordic.ko +set kodebugbz2file ${srcdir}/${subdir}/cordic.ko.debug.bz2 +set kodebugfile ${objdir}/${subdir}/cordic.ko.debug + +if {[catch "system \"bzip2 -dc ${kobz2file} >${kofile}\""] != 0} { + untested "failed bzip2 for ${kobz2file}" + return -1 +} +if {[catch "system \"bzip2 -dc ${kodebugbz2file} >${kodebugfile}\""] != 0} { + untested "failed bzip2 for ${kodebugbz2file}" + return -1 +} + +gdb_exit +gdb_start +gdb_reinitialize_dir $srcdir/$subdir + +# This test won't work properly if system debuginfo is installed. +# Test message is suppressed by "" as otherwise we could print PASS+UNTESTED +# result to gdb.sum making a false feeling the issue has been tested. +gdb_test_no_output "set debug-file-directory" "" + +gdb_load ${kofile} + +set test "show architecture" +gdb_test_multiple $test $test { + -re "\r\nThe target architecture is set automatically \\(currently powerpc:common64\\)\r\n$gdb_prompt $" { + pass $test + } + -re "\r\nThe target architecture is set automatically \\(currently .*\\)\r\n$gdb_prompt $" { + untested "powerpc:common64 is not supported" + } +}