From FEDORA_PATCHES Mon Sep 17 00:00:00 2001 From: Fedora GDB patches Date: Fri, 27 Oct 2017 21:07:50 +0200 Subject: gdb-6.6-buildid-locate-solib-missing-ids.patch ;; Fix loading of core files without build-ids but with build-ids in executables. ;; Load strictly build-id-checked core files only if no executable is specified ;; (Jan Kratochvil, RH BZ 1339862). ;;=push+jan gdb returns an incorrect back trace when applying a debuginfo https://bugzilla.redhat.com/show_bug.cgi?id=1339862 diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c --- a/gdb/solib-svr4.c +++ b/gdb/solib-svr4.c @@ -1340,14 +1340,27 @@ struct svr4_library_list } { - struct bfd_build_id *build_id; + struct bfd_build_id *build_id = NULL; strncpy (newobj->so_original_name, buffer.get (), SO_NAME_MAX_PATH_SIZE - 1); newobj->so_original_name[SO_NAME_MAX_PATH_SIZE - 1] = '\0'; /* May get overwritten below. */ strcpy (newobj->so_name, newobj->so_original_name); - build_id = build_id_addr_get (((lm_info_svr4 *) newobj->lm_info)->l_ld); + /* In the case the main executable was found according to its build-id + (from a core file) prevent loading a different build of a library + with accidentally the same SO_NAME. + + It suppresses bogus backtraces (and prints "??" there instead) if + the on-disk files no longer match the running program version. + + If the main executable was not loaded according to its build-id do + not do any build-id checking of the libraries. There may be missing + build-ids dumped in the core file and we would map all the libraries + to the only existing file loaded that time - the executable. */ + if (symfile_objfile != NULL + && (symfile_objfile->flags & OBJF_BUILD_ID_CORE_LOADED) != 0) + build_id = build_id_addr_get (li->l_ld); if (build_id != NULL) { char *name, *build_id_filename; @@ -1362,23 +1375,7 @@ struct svr4_library_list xfree (name); } else - { - debug_print_missing (newobj->so_name, build_id_filename); - - /* In the case the main executable was found according to - its build-id (from a core file) prevent loading - a different build of a library with accidentally the - same SO_NAME. - - It suppresses bogus backtraces (and prints "??" there - instead) if the on-disk files no longer match the - running program version. */ - - if (symfile_objfile != NULL - && (symfile_objfile->flags - & OBJF_BUILD_ID_CORE_LOADED) != 0) - newobj->so_name[0] = 0; - } + debug_print_missing (newobj->so_name, build_id_filename); xfree (build_id_filename); xfree (build_id); diff --git a/gdb/testsuite/gdb.base/gcore-buildid-exec-but-not-solib-lib.c b/gdb/testsuite/gdb.base/gcore-buildid-exec-but-not-solib-lib.c new file mode 100644 --- /dev/null +++ b/gdb/testsuite/gdb.base/gcore-buildid-exec-but-not-solib-lib.c @@ -0,0 +1,21 @@ +/* Copyright 2010 Free Software Foundation, Inc. + + This file is part of GDB. + + 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 . */ + +void +lib (void) +{ +} diff --git a/gdb/testsuite/gdb.base/gcore-buildid-exec-but-not-solib-main.c b/gdb/testsuite/gdb.base/gcore-buildid-exec-but-not-solib-main.c new file mode 100644 --- /dev/null +++ b/gdb/testsuite/gdb.base/gcore-buildid-exec-but-not-solib-main.c @@ -0,0 +1,25 @@ +/* Copyright 2010 Free Software Foundation, Inc. + + This file is part of GDB. + + 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 . */ + +extern void lib (void); + +int +main (void) +{ + lib (); + return 0; +} diff --git a/gdb/testsuite/gdb.base/gcore-buildid-exec-but-not-solib.exp b/gdb/testsuite/gdb.base/gcore-buildid-exec-but-not-solib.exp new file mode 100644 --- /dev/null +++ b/gdb/testsuite/gdb.base/gcore-buildid-exec-but-not-solib.exp @@ -0,0 +1,105 @@ +# Copyright 2016 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 . + +if {[skip_shlib_tests]} { + return 0 +} + +set testfile "gcore-buildid-exec-but-not-solib" +set srcmainfile ${testfile}-main.c +set srclibfile ${testfile}-lib.c +set libfile [standard_output_file ${testfile}-lib.so] +set objfile [standard_output_file ${testfile}-main.o] +set executable ${testfile}-main +set binfile [standard_output_file ${executable}] +set gcorefile [standard_output_file ${executable}.gcore] +set outdir [file dirname $binfile] + +if { [gdb_compile_shlib ${srcdir}/${subdir}/${srclibfile} ${libfile} "debug additional_flags=-Wl,--build-id"] != "" + || [gdb_compile ${srcdir}/${subdir}/${srcmainfile} ${objfile} object {debug}] != "" } { + unsupported "-Wl,--build-id compilation failed" + return -1 +} +set opts [list debug shlib=${libfile} "additional_flags=-Wl,--build-id"] +if { [gdb_compile ${objfile} ${binfile} executable $opts] != "" } { + unsupported "-Wl,--build-id compilation failed" + return -1 +} + +clean_restart $executable +gdb_load_shlib $libfile + +# Does this gdb support gcore? +set test "help gcore" +gdb_test_multiple $test $test { + -re "Undefined command: .gcore.*\r\n$gdb_prompt $" { + # gcore command not supported -- nothing to test here. + unsupported "gdb does not support gcore on this target" + return -1; + } + -re "Save a core file .*\r\n$gdb_prompt $" { + pass $test + } +} + +if { ![runto lib] } then { + return -1 +} + +set escapedfilename [string_to_regexp ${gcorefile}] + +set test "save a corefile" +gdb_test_multiple "gcore ${gcorefile}" $test { + -re "Saved corefile ${escapedfilename}\r\n$gdb_prompt $" { + pass $test + } + -re "Can't create a corefile\r\n$gdb_prompt $" { + unsupported $test + return -1 + } +} + +# Now restart gdb and load the corefile. + +clean_restart $executable +gdb_load_shlib $libfile + +set buildid [build_id_debug_filename_get $libfile] + +regsub {\.debug$} $buildid {} buildid + +set debugdir [standard_output_file ${testfile}-debugdir] +file delete -force -- $debugdir + +file mkdir $debugdir/[file dirname $libfile] +file copy $libfile $debugdir/${libfile} + +file mkdir $debugdir/[file dirname $buildid] +file copy $libfile $debugdir/${buildid} + +remote_exec build "ln -s /lib ${debugdir}/" +remote_exec build "ln -s /lib64 ${debugdir}/" +# /usr is not needed, all the libs are in /lib64: libm.so.6 libc.so.6 ld-linux-x86-64.so.2 + +gdb_test "set solib-absolute-prefix $debugdir" + +gdb_test_no_output "set debug-file-directory $debugdir" "set debug-file-directory" + +gdb_test "core ${gcorefile}" "Core was generated by .*" "re-load generated corefile" + +gdb_test "frame" "#0 \[^\r\n\]* lib .*" "library got loaded" + +gdb_test "bt" +gdb_test "info shared"