diff options
| -rw-r--r-- | gdb/ChangeLog | 12 | ||||
| -rw-r--r-- | gdb/common/signals-state-save-restore.c | 32 | ||||
| -rw-r--r-- | gdb/common/signals-state-save-restore.h | 5 | ||||
| -rw-r--r-- | gdb/gdbserver/ChangeLog | 6 | ||||
| -rw-r--r-- | gdb/gdbserver/server.c | 2 | ||||
| -rw-r--r-- | gdb/main.c | 3 | ||||
| -rw-r--r-- | gdb/testsuite/ChangeLog | 5 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.base/libsegfault.exp | 84 |
8 files changed, 141 insertions, 8 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 0eeff94..24ccfe6 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,17 @@ 2018-01-05 Pedro Alves <palves@redhat.com> + PR gdb/18653 + * common/signals-state-save-restore.c + (save_original_signals_state): New parameter 'quiet'. Warn if we + find a custom handler preinstalled, instead of internal erroring. + But only warn if !quiet. + * common/signals-state-save-restore.h + (save_original_signals_state): New parameter 'quiet'. + * main.c (captured_main_1): Move save_original_signals_state call + after option handling, and pass QUIET. + +2018-01-05 Pedro Alves <palves@redhat.com> + * spu-tdep.c (spu_catch_start): Pass symbol_name_match_type::SEARCH_NAME to block_lookup_symbol. diff --git a/gdb/common/signals-state-save-restore.c b/gdb/common/signals-state-save-restore.c index 7c7afd3..eb281dd 100644 --- a/gdb/common/signals-state-save-restore.c +++ b/gdb/common/signals-state-save-restore.c @@ -35,7 +35,7 @@ static sigset_t original_signal_mask; /* See signals-state-save-restore.h. */ void -save_original_signals_state (void) +save_original_signals_state (bool quiet) { #ifdef HAVE_SIGACTION int i; @@ -45,6 +45,8 @@ save_original_signals_state (void) if (res == -1) perror_with_name (("sigprocmask")); + bool found_preinstalled = false; + for (i = 1; i < NSIG; i++) { struct sigaction *oldact = &original_signal_actions[i]; @@ -59,9 +61,31 @@ save_original_signals_state (void) perror_with_name (("sigaction")); /* If we find a custom signal handler already installed, then - this function was called too late. */ - if (oldact->sa_handler != SIG_DFL && oldact->sa_handler != SIG_IGN) - internal_error (__FILE__, __LINE__, _("unexpected signal handler")); + this function was called too late. This is a warning instead + of an internal error because this can also happen if you + LD_PRELOAD a library that installs a signal handler early via + __attribute__((constructor)), like libSegFault.so. */ + if (!quiet + && oldact->sa_handler != SIG_DFL + && oldact->sa_handler != SIG_IGN) + { + found_preinstalled = true; + + /* Use raw fprintf here because we're being called in early + startup, because GDB's filtered streams are are + created. */ + fprintf (stderr, + _("warning: Found custom handler for signal " + "%d (%s) preinstalled.\n"), i, + strsignal (i)); + } + } + + if (found_preinstalled) + { + fprintf (stderr, _("\ +Some signal dispositions inherited from the environment (SIG_DFL/SIG_IGN)\n\ +won't be propagated to spawned programs.\n")); } #endif } diff --git a/gdb/common/signals-state-save-restore.h b/gdb/common/signals-state-save-restore.h index 71ec08e..276ddc4 100644 --- a/gdb/common/signals-state-save-restore.h +++ b/gdb/common/signals-state-save-restore.h @@ -28,9 +28,10 @@ back to what was originally inherited from gdb/gdbserver's parent, just before execing the target program to debug. */ -/* Save the signal state of all signals. */ +/* Save the signal state of all signals. If !QUIET, warn if we detect + a custom signal handler preinstalled. */ -extern void save_original_signals_state (void); +extern void save_original_signals_state (bool quiet); /* Restore the signal state of all signals. */ diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog index 1170a06..2299c8e 100644 --- a/gdb/gdbserver/ChangeLog +++ b/gdb/gdbserver/ChangeLog @@ -1,3 +1,9 @@ +2018-01-05 Pedro Alves <palves@redhat.com> + + PR gdb/18653 + * server.c (captured_main): Pass quiet=false to + save_original_signals_state. + 2018-01-01 Joel Brobecker <brobecker@adacore.com> * gdbreplay.c (gdbreplay_version): Update copyright year in diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c index 3367555..1a72123 100644 --- a/gdb/gdbserver/server.c +++ b/gdb/gdbserver/server.c @@ -3712,7 +3712,7 @@ captured_main (int argc, char *argv[]) opened by remote_prepare. */ notice_open_fds (); - save_original_signals_state (); + save_original_signals_state (false); /* We need to know whether the remote connection is stdio before starting the inferior. Inferiors created in this scenario have @@ -506,7 +506,6 @@ captured_main_1 (struct captured_main_args *context) bfd_init (); notice_open_fds (); - save_original_signals_state (); saved_command_line = (char *) xstrdup (""); @@ -849,6 +848,8 @@ captured_main_1 (struct captured_main_args *context) quiet = 1; } + save_original_signals_state (quiet); + /* Try to set up an alternate signal stack for SIGSEGV handlers. */ setup_alternate_signal_stack (); diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 18ad740..e87099b 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2018-01-05 Pedro Alves <palves@redhat.com> + + PR gdb/18653 + * gdb.base/libsegfault.exp: New. + 2018-01-05 Joel Brobecker <brobecker@adacore.com> PR gdb/22670 diff --git a/gdb/testsuite/gdb.base/libsegfault.exp b/gdb/testsuite/gdb.base/libsegfault.exp new file mode 100644 index 0000000..e1de253 --- /dev/null +++ b/gdb/testsuite/gdb.base/libsegfault.exp @@ -0,0 +1,84 @@ +# Copyright 2017-2018 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 <http://www.gnu.org/licenses/>. + +# This file is part of the gdb testsuite. + +# Test that GDB tolerates being started with libSegFault.so preloaded +# with LD_PRELOAD, and that GDB warns about a custom SIGSEGV custom +# handler. See PR gdb/18653 +# <https://sourceware.org/bugzilla/show_bug.cgi?id=18653#c7>. + +# We cannot expect remote hosts to see environment variables set on +# the local machine. +if { [is_remote host] } { + unsupported "can't set environment variables on remote host" + return -1 +} + +# Spawn GDB with LIB preloaded with LD_PRELOAD. CMDLINE_OPTS are +# command line options passed to GDB. + +proc gdb_spawn_with_ld_preload {lib cmdline_opts} { + global env + + save_vars { env(LD_PRELOAD) } { + if { ![info exists env(LD_PRELOAD) ] + || $env(LD_PRELOAD) == "" } { + set env(LD_PRELOAD) "$lib" + } else { + append env(LD_PRELOAD) ":$lib" + } + + gdb_spawn_with_cmdline_opts $cmdline_opts + } +} + +proc test_libsegfault {} { + global gdb_prompt + + set libsegfault "libSegFault.so" + + # When started normally, if libSegFault.so is preloaded, GDB + # should warn about not being able to propagate the signal + # disposition of SIGSEGV. + gdb_exit + gdb_spawn_with_ld_preload $libsegfault "" + + set test "gdb emits custom handler warning" + gdb_test_multiple "" $test { + -re "cannot be preloaded.*\r\n$gdb_prompt $" { + # Glibc 2.22 outputs: + # ERROR: ld.so: object 'libSegFault.so' from LD_PRELOAD cannot be preloaded (cannot open shared object file): ignored. + untested "cannot preload libSegFault.so" + return + } + -re "Found custom handler.*won't be propagated.*\r\n$gdb_prompt $" { + pass $test + } + } + + # "-q" should disable the warning, though. + gdb_exit + gdb_spawn_with_ld_preload $libsegfault "-q" + + set test "quiet suppresses custom handler warning" + gdb_test_multiple "" $test { + -re "^$gdb_prompt $" { + pass $test + } + } +} + +test_libsegfault |