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| author | Pedro Alves <palves@redhat.com> | 2016-08-09 20:16:20 +0100 |
|---|---|---|
| committer | Pedro Alves <palves@redhat.com> | 2016-08-09 20:16:20 +0100 |
| commit | f348d89aeccaf3eb613e2f31a823baa64300bf88 (patch) | |
| tree | 66f0119540539603832d1b3170848b1f9711b43a /gdb/fork-child.c | |
| parent | 7cfee229f1eb6e3ee98b63918a5189a330284751 (diff) | |
| download | gdb-f348d89aeccaf3eb613e2f31a823baa64300bf88.zip gdb-f348d89aeccaf3eb613e2f31a823baa64300bf88.tar.gz gdb-f348d89aeccaf3eb613e2f31a823baa64300bf88.tar.bz2 | |
Fix PR gdb/18653: gdb disturbs inferior's inherited signal dispositions
gdb's (or gdbserver's) own signal handling should not interfere with
the signal dispositions their spawned children inherit. However, it
currently does. For example, some paths in gdb cause SIGPIPE to be
set to SIG_IGN, and as consequence, the child starts with SIGPIPE to
set to SIG_IGN too, even though gdb was started with SIGPIPE set to
SIG_DFL.
This is because the exec family of functions does not reset the signal
disposition of signals that are set to SIG_IGN:
http://pubs.opengroup.org/onlinepubs/7908799/xsh/execve.html
Signals set to the default action (SIG_DFL) in the calling process
image are set to the default action in the new process
image. Signals set to be ignored (SIG_IGN) by the calling process
image are set to be ignored by the new process image. Signals set to
be caught by the calling process image are set to the default action
in the new process image (see <signal.h>).
And neither does it reset signal masks or flags.
In order to be transparent, when spawning new child processes to debug
(with "run", etc.), reset signal actions and mask back to what was
originally inherited from gdb/gdbserver's parent, just before execing
the target program to debug.
gdb/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
PR gdb/18653
* Makefile.in (SFILES): Add
common/signals-state-save-restore.c.
(HFILES_NO_SRCDIR): Add common/signals-state-save-restore.h.
(COMMON_OBS): Add signals-state-save-restore.o.
(signals-state-save-restore.o): New rule.
* configure: Regenerate.
* fork-child.c: Include "signals-state-save-restore.h".
(fork_inferior): Call restore_original_signals_state.
* main.c: Include "signals-state-save-restore.h".
(captured_main): Call save_original_signals_state.
* common/common.m4: Add sigaction to AC_CHECK_FUNCS checks.
* common/signals-state-save-restore.c: New file.
* common/signals-state-save-restore.h: New file.
gdb/gdbserver/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
PR gdb/18653
* Makefile.in (OBS): Add signals-state-save-restore.o.
(signals-state-save-restore.o): New rule.
* config.in: Regenerate.
* configure: Regenerate.
* linux-low.c: Include "signals-state-save-restore.h".
(linux_create_inferior): Call
restore_original_signals_state.
* server.c: Include "dispositions-save-restore.h".
(captured_main): Call save_original_signals_state.
gdb/testsuite/ChangeLog:
2016-08-09 Pedro Alves <palves@redhat.com>
PR gdb/18653
* gdb.base/signals-state-child.c: New file.
* gdb.base/signals-state-child.exp: New file.
* gdb.gdb/selftest.exp (do_steps_and_nexts): Add new pattern.
Diffstat (limited to 'gdb/fork-child.c')
| -rw-r--r-- | gdb/fork-child.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/gdb/fork-child.c b/gdb/fork-child.c index 8ac3bef..6856cf6 100644 --- a/gdb/fork-child.c +++ b/gdb/fork-child.c @@ -32,7 +32,7 @@ #include "solib.h" #include "filestuff.h" #include "top.h" - +#include "signals-state-save-restore.h" #include <signal.h> /* This just gets used as a default if we can't find SHELL. */ @@ -366,6 +366,8 @@ fork_inferior (char *exec_file_arg, char *allargs, char **env, saying "not parent". Sorry; you'll have to use print statements! */ + restore_original_signals_state (); + /* There is no execlpe call, so we have to set the environment for our child in the global variable. If we've vforked, this clobbers the parent, but environ is restored a few lines down |