On Mon, 18 Mar 2013 16:46:03 +0100, Mark Wielaard wrote:
Yeah, it seems good to fix this. I was just wondering if there was some other way to trigger it. BTW dwfl_report_segment is a public function.
Normally one cannot trigger this bug using standard elfutils src/ binaries.
./src/addr2line -p PID -> dwfl_standard_argp -> dwfl_linux_proc_report -> -> /proc/PID/maps -> dwfl_report_module
./src/addr2line --core=CORE -> dwfl_standard_argp -> dwfl_core_file_report -> -> dwfl_report_segment
For core files this happens as build-ids are present there. One needs to disable build-ids from the core file. I tried it the official way of bit 4 in coredump_filter but this does not work, filed kernel Bug: https://bugzilla.redhat.com/show_bug.cgi?id=923827
So I rather patched out the first build-id page of libc.so.6 from the core file and reproduced the elfutils bug:
(echo -e '#include<unistd.h>\nint main(void){return pause();}'|gcc -Wall -x c -;ulimit -c unlimited;./a.out&p=$!;sleep 1;cat /proc/$p/maps >a.out.maps;kill -SEGV $p)
a.out.maps: 7f9c4f6dc000-7f9c4f889000 r-xp 00000000 fd:01 75366917 /usr/lib64/libc-2.16.so + readelf -Wl a.out.core Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align LOAD 0x004000 0x00007f9c4f6dc000 0x0000000000000000 0x001000 0x1ad000 R E 0x1000 -> dd if=/dev/zero of=a.out.core conv=notrunc seek=$[0x4000] count=$[0x1000] bs=1
This really finally invoked dwfl_report_elf: #0 __libdwfl_report_elf at dwfl_report_elf.c:46 #1 in dwfl_report_elf at dwfl_report_elf.c:274 #2 in report_r_debug at link_map.c:397 #3 in dwfl_link_map_report at link_map.c:875 #4 in dwfl_core_file_report at core-file.c:454 #5 in parse_opt at argp-std.c:317
$ gdb ./a.out ./a.out.core Program terminated with signal 11, Segmentation fault. #0 0x00007f9c4f7973d0 in __pause_nocancel () at ../sysdeps/unix/syscall-template.S:81
Unpatched elfutils: $ ../src/addr2line -S -e ./a.out --core=./a.out.core.orig 0x00007f9c4f7973d0 pause+0x10 ../sysdeps/unix/syscall-template.S:81 $ ../src/addr2line -S -e ./a.out --core=./a.out.core 0x00007f9c4f7973d0 ?? ??:0
Patched elfutils: $ ../src/addr2line -S -e ./a.out --core=./a.out.core.orig 0x00007f9c4f7973d0 pause+0x10 ../sysdeps/unix/syscall-template.S:81 $ ../src/addr2line -S -e ./a.out --core=./a.out.core 0x00007f9c4f7973d0 pause+0x10 ../sysdeps/unix/syscall-template.S:81
FYI one needs to be on unprelinked system, otherwise libc.so.6 l_addr will be always 0 so no alignment bug can be reproduced with 0.
But I find this reproducer from src/addr2line a bit too complicated, relying on r_debug may make dependencies on system paths etc. so I find the artificial testcase of mine to be a safer/easier way.
BTW. For the git commit message it is nice if the first line (< 78 chars) is a short summary of the fix. That way a git shortlog looks a little easier to read.
done.
Checked in.
Thanks, Jan
commit a1d44825ffc756ed6c0dca3a836c1ff9f0ec151f Author: Jan Kratochvil jan.kratochvil@redhat.com Date: Tue Mar 19 13:40:13 2013 +0100
Fix dwfl_report_elf BASE alignment
libdwfl/ * dwfl_report_elf.c (__libdwfl_report_elf): Remove BASE aligning.
tests/ * Makefile.am (check_PROGRAMS): Add dwfl-report-elf-align. (TESTS): Add run-dwfl-report-elf-align.sh. (EXTRA_DIST): Add run-dwfl-report-elf-align.sh and testfile-dwfl-report-elf-align-shlib.so.bz2 . (dwfl_report_elf_align_LDADD): New. * dwfl-report-elf-align.c: New file. * run-dwfl-report-elf-align.sh: New file. * testfile-dwfl-report-elf-align-shlib.so.bz2: New file.
Signed-off-by: Jan Kratochvil jan.kratochvil@redhat.com
diff --git a/libdwfl/ChangeLog b/libdwfl/ChangeLog index 15a6c9c..41fc84b 100644 --- a/libdwfl/ChangeLog +++ b/libdwfl/ChangeLog @@ -1,3 +1,7 @@ +2013-03-20 Jan Kratochvil jan.kratochvil@redhat.com + + * dwfl_report_elf.c (__libdwfl_report_elf): Remove BASE aligning. + 2013-03-12 Mark Wielaard mjw@redhat.com
* dwfl_getsrclines.c (dwfl_getsrclines): Return 0 on success. diff --git a/libdwfl/dwfl_report_elf.c b/libdwfl/dwfl_report_elf.c index 174ce7c..d706170 100644 --- a/libdwfl/dwfl_report_elf.c +++ b/libdwfl/dwfl_report_elf.c @@ -181,8 +181,6 @@ __libdwfl_report_elf (Dwfl *dwfl, const char *name, const char *file_name, { vaddr = ph->p_vaddr & -ph->p_align; address_sync = ph->p_vaddr + ph->p_memsz; - if ((base & (ph->p_align - 1)) != 0) - base = (base + ph->p_align - 1) & -ph->p_align; start = base + vaddr; break; } diff --git a/tests/ChangeLog b/tests/ChangeLog index ca06a55..62b589d 100644 --- a/tests/ChangeLog +++ b/tests/ChangeLog @@ -1,3 +1,14 @@ +2013-03-20 Jan Kratochvil jan.kratochvil@redhat.com + + * Makefile.am (check_PROGRAMS): Add dwfl-report-elf-align. + (TESTS): Add run-dwfl-report-elf-align.sh. + (EXTRA_DIST): Add run-dwfl-report-elf-align.sh and + testfile-dwfl-report-elf-align-shlib.so.bz2 . + (dwfl_report_elf_align_LDADD): New. + * dwfl-report-elf-align.c: New file. + * run-dwfl-report-elf-align.sh: New file. + * testfile-dwfl-report-elf-align-shlib.so.bz2: New file. + 2013-03-12 Mark Wielaard mjw@redhat.com
* run-dwfllines.sh: New test. diff --git a/tests/Makefile.am b/tests/Makefile.am index a5f7a8c..9b0bbf1 100644 --- a/tests/Makefile.am +++ b/tests/Makefile.am @@ -51,7 +51,8 @@ check_PROGRAMS = arextract arsymtest newfile saridx scnnames sectiondump \ dwfl-bug-getmodules dwarf-getmacros addrcfi \ test-flag-nobits dwarf-getstring rerequest_tag \ alldts md5-sha1-test typeiter low_high_pc \ - test-elf_cntl_gelf_getshdr dwflsyms dwfllines + test-elf_cntl_gelf_getshdr dwflsyms dwfllines \ + dwfl-report-elf-align asm_TESTS = asm-tst1 asm-tst2 asm-tst3 asm-tst4 asm-tst5 \ asm-tst6 asm-tst7 asm-tst8 asm-tst9
@@ -85,7 +86,8 @@ TESTS = run-arextract.sh run-arsymtest.sh newfile test-nlist \ run-readelf-d.sh run-readelf-gdb_index.sh run-unstrip-n.sh \ run-low_high_pc.sh run-macro-test.sh run-elf_cntl_gelf_getshdr.sh \ run-test-archive64.sh run-readelf-vmcoreinfo.sh \ - run-readelf-mixed-corenote.sh run-dwfllines.sh + run-readelf-mixed-corenote.sh run-dwfllines.sh \ + run-dwfl-report-elf-align.sh
if !STANDALONE check_PROGRAMS += msg_tst md5-sha1-test @@ -193,7 +195,8 @@ EXTRA_DIST = run-arextract.sh run-arsymtest.sh \ testfile65.bz2 testfile67.bz2 testfile68.bz2 \ testfile69.core.bz2 testfile69.so.bz2 \ testfile70.core.bz2 testfile70.exec.bz2 \ - run-dwfllines.sh + run-dwfllines.sh run-dwfl-report-elf-align.sh \ + testfile-dwfl-report-elf-align-shlib.so.bz2
if USE_VALGRIND valgrind_cmd="valgrind -q --trace-children=yes --error-exitcode=1 --run-libc-freeres=no" @@ -302,6 +305,7 @@ low_high_pc_LDADD = $(libdw) $(libelf) $(libmudflap) test_elf_cntl_gelf_getshdr_LDADD = $(libelf) $(libmudflap) dwflsyms_LDADD = $(libdw) $(libelf) $(libmudflap) dwfllines_LDADD = $(libdw) $(libelf) $(libmudflap) +dwfl_report_elf_align_LDADD = $(libdw) $(libmudflap)
if GCOV check: check-am coverage diff --git a/tests/dwfl-report-elf-align.c b/tests/dwfl-report-elf-align.c new file mode 100644 index 0000000..0e8bfe3 --- /dev/null +++ b/tests/dwfl-report-elf-align.c @@ -0,0 +1,72 @@ +/* Test program for dwfl_report_elf incorrect BASE alignment. + Copyright (C) 2013 Red Hat, 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/. */ + +#include <config.h> +#include <assert.h> +#include <inttypes.h> +#include <stdio.h> +#include <stdio_ext.h> +#include <error.h> +#include <locale.h> +#include <string.h> +#include <stdlib.h> +#include ELFUTILS_HEADER(dwfl) + + +static const Dwfl_Callbacks offline_callbacks = + { + .find_debuginfo = INTUSE(dwfl_standard_find_debuginfo), + .section_address = INTUSE(dwfl_offline_section_address), + }; + + +int +main (int argc, char **argv) +{ + /* We use no threads here which can interfere with handling a stream. */ + (void) __fsetlocking (stdout, FSETLOCKING_BYCALLER); + + /* Set locale. */ + (void) setlocale (LC_ALL, ""); + + if (argc != 5) + error (1, 0, "dwfl-report-elf-align shlib.so base funcaddr funcname"); + + Dwfl *dwfl = dwfl_begin (&offline_callbacks); + assert (dwfl != NULL); + + char *endptr; + uintptr_t base = strtoull (argv[2], &endptr, 0); + assert (endptr && !*endptr); + + Dwfl_Module *mod = dwfl_report_elf (dwfl, argv[1], argv[1], -1, base); + assert (mod != NULL); + + uintptr_t funcaddr = strtoull (argv[3], &endptr, 0); + assert (endptr && !*endptr); + + Dwfl_Module *mod_found = dwfl_addrmodule (dwfl, funcaddr); + assert (mod_found == mod); + + const char *symname = dwfl_module_addrname (mod, funcaddr); + assert (symname != NULL); + assert (strcmp (symname, argv[4]) == 0); + + dwfl_end (dwfl); + + return 0; +} diff --git a/tests/run-dwfl-report-elf-align.sh b/tests/run-dwfl-report-elf-align.sh new file mode 100755 index 0000000..d032aba --- /dev/null +++ b/tests/run-dwfl-report-elf-align.sh @@ -0,0 +1,44 @@ +#! /bin/sh +# Copyright (C) 2013 Red Hat, 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/. + +. $srcdir/test-subr.sh + +testfiles testfile-dwfl-report-elf-align-shlib.so + +# /proc/PID/maps when the process was running: +# 7f3560c92000-7f3560c93000 r-xp 00000000 fd:02 25037063 testfile-dwfl-report-elf-align-shlib.so +# 7f3560c93000-7f3560e92000 ---p 00001000 fd:02 25037063 testfile-dwfl-report-elf-align-shlib.so +# 7f3560e92000-7f3560e93000 rw-p 00000000 fd:02 25037063 testfile-dwfl-report-elf-align-shlib.so +# testfile-dwfl-report-elf-align-shlib.so: +# Program Headers: +# Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align +# LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x00065c 0x00065c R E 0x200000 +# LOAD 0x000660 0x0000000000200660 0x0000000000200660 0x0001f0 0x000200 RW 0x200000 +# Symbol table '.dynsym' contains 12 entries: +# Num: Value Size Type Bind Vis Ndx Name +# 8: 000000000000057c 11 FUNC GLOBAL DEFAULT 11 shlib +# GDB output showing proper relocation: +# #1 0x00007f3560c92585 in shlib () from ./testfile-dwfl-report-elf-align-shlib.so +# +# 0x7f3560c92000 is VMA address of first byte of testfile-dwfl-report-elf-align-shlib.so. +# 0x7f3560c92585 = 0x7f3560c92000 + 0x585 +# where 0x585 is any address inside the shlib function: 0x57c .. 0x57c + 11 -1 + +testrun ./dwfl-report-elf-align ./testfile-dwfl-report-elf-align-shlib.so \ + 0x7f3560c92000 0x7f3560c92585 shlib + +exit 0 diff --git a/tests/testfile-dwfl-report-elf-align-shlib.so.bz2 b/tests/testfile-dwfl-report-elf-align-shlib.so.bz2 new file mode 100755 index 0000000000000000000000000000000000000000..1f35df98ffa1dc5883acce9f3b567891f024e43e GIT binary patch literal 1546 zcmV+l2KD(uT4*^jL0KkKSx!>Q^#BDofB*mg{r}ege}Dh~eqaCp|NPHtQJ_~;*l2BG zOTgc3=V{OczV0wl*EV&Ux+Vsvq$!GRDYVLH^%)OH03K67(?N)OnE)Q9ho}GpKma{J zG-zq+01c!70L1-B^#-ZvAeo?;L8609(E*?ypa1{^Mw$Q`01X2`05oXOG5`S3003%Y z5t3q))DKNZqyPqiqts{vMnEzE8Vv@G0LTo000000G|8X<5E>Z<nKaNangc^jnl!+S zjG7FFOoJm#jT&ScGyuUGXfX`{44N4*5unkaNRXo`qHPUElW7}MWi-*XHiJosX`s_a zfYIt17>odeMt}_gpazW|Q$s^cKpHg2H-+9dek8nF7>Hhj5mLIf5qL%9+>6>y987dm zCZK~BX2dnDlxT!Vv|)gRf)rHrl_+cSr#B6QmN68Q5ERR81@S3MbLS;$5km9x0pP$G zM2H4i#vG?TgiSG1LH7(9!XScO2fmsVhf-lP9&_G4yl6aXCgoWS7A{{z_p4}|6SR;h z6*mr}ndBsrNDCEX_!6&#%_Zr^;5J~l6PI^+((2q?*zY)Mc0VJ)3gom7|3vJ|J&RBP zP{LtisOagWU?fw4y0tV;s-(j6=YsBehA7d`?5>KYx@&L(GCXbfMLnj6Wv#hGs(roo z6r*VdYIpb%IIYG`3|8sO@h3fn{Zc|&rjj*GLIAM)rj@yAi6+nx#C2^i4ncb40Y<mX zNhC?6tu!nROdxFlHmnULu<T(Oc@TfkABX1f<G9!8C+M-5JzR1FTx6xhmJ$O;)Tnt0 zWf6#3nPU|a24*XHyEjF>Xl0?5Vcg8m8KCajWvw!0?1;G>c<3BbQiT$)H)s0IL+U6= z1sW#KxtMobSt7>13yc-^v)K2z-Q|vJ#$vR@-M0@!m_zF)0m5J`b|Z?=mMhKv8yMtD zB`HK&RAov8*xH~0LWXiZ8)?~|l^;o_Qmv2s(0~OA+wmPG6r#pmPeX!htFmK+r!tU6 zwTmm2`5K6X;>`&&mwm`)K+EmzCx*P*90W_1F=Rrhz;dAubJk&G&HdhDJZ8a#b?RzP z_Xi$$d?ZVH4Y~tc0*E>I>a6cgY>-VaxVQ7lYC)NoyIV*kDvUsb8siyqLV~B20eaN3 zmtePOALR=M_uh676G!aHx<D~4!^|w59M@^nmNmy7h~rF*D&;GvLm|NNDxLqB{`<3= zU1nB#wTp-NnVKValj$~yZH)!gD#=>BWSVZ0hQSdUZpuqryJ+&fcPc5sc40LjNQ%A& zMPTb)*?4Kn+wa{%)PS}*W(IwSkj3M)Nv!0^H;>D7GnVjN;D>fw@OHjVRu)`kxJ(HR z^kE4ll5GX<dM}<cn9rD+i>@s>USO4$W%soO*><0^q@LJ$NdHJu;?1v#OeV)n)nT5y zGg-)rwfmmhv7|g})b71@SfdZC@7rHU*Ww;*Twl$XFq>k#pofB4mL0|{>%B@Mc2hZf zbo~T*t6Z|(;ngECShMRf1xrE+hqM=FzU0$T{6dAJ0#R#Y`cP*VYk@%#wmPA{g4aY@ z$ci)7J?SPCyzrdyF!?Mla8wvSWx`xWvCx@A2JNN-RcymRsuU|6jSOnS?!zZENfhe^ zJ?|F}4rEsGs|7l9C{qJ^P9~M3vKb^AGiCut2V4$ia>9`<4WmI+gCaWjpm=hoRBD72 zLjXh$BMY?zAtyYfx|(1Wa6^JAv<OtEVF8zHy6P%5RLceg_&`CQojBrq;AY}&&D6mS zoh4Co2J65w#CK9;I<2Dd2}EU}$SF$G-59QP8TeHl@&yG}5c)=@woKr964`XXD1rnd zTOiQfUs^fTYoJ@MQJbw<{#zSNjv8$e*v{Eo6D&Sreh^xKSO>zk8^QZ@rz|pqAnI(b z+yTe2-;sHuejQXC-^9z6TwZ8bxsg#+K_aMZ$PhtWBaf+dR~2Z~B)k#}{ayWAj-VT~ w3CkdHfdqj_tI8j#a!WvjqM=LVwVFt(S=+gGkst7LqkqNRkxmpO6O^*OK%{@Z*#H0l
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