diff options
| -rw-r--r-- | gdb/ChangeLog | 6 | ||||
| -rw-r--r-- | gdb/gdbsupport/alt-stack.h | 70 | ||||
| -rw-r--r-- | gdb/main.c | 26 |
3 files changed, 78 insertions, 24 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 9d4fe36..7535016 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,11 @@ 2019-11-26 Tom Tromey <tom@tromey.com> + * main.c (setup_alternate_signal_stack): Remove. + (captured_main_1): Use gdb::alternate_signal_stack. + * gdbsupport/alt-stack.h: New file. + +2019-11-26 Tom Tromey <tom@tromey.com> + * gdbsupport/signals-state-save-restore.c (original_signal_mask): Remove comment. (save_original_signals_state, restore_original_signals_state): Use diff --git a/gdb/gdbsupport/alt-stack.h b/gdb/gdbsupport/alt-stack.h new file mode 100644 index 0000000..1708fb4 --- /dev/null +++ b/gdb/gdbsupport/alt-stack.h @@ -0,0 +1,70 @@ +/* Temporarily install an alternate signal stack + + Copyright (C) 2019 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 <http://www.gnu.org/licenses/>. */ + +#ifndef GDBSUPPORT_ALT_STACK_H +#define GDBSUPPORT_ALT_STACK_H + +#include <signal.h> + +namespace gdb +{ + +/* Try to set up an alternate signal stack for SIGSEGV handlers. + This allows us to handle SIGSEGV signals generated when the + normal process stack is exhausted. If this stack is not set + up (sigaltstack is unavailable or fails) and a SIGSEGV is + generated when the normal stack is exhausted then the program + will behave as though no SIGSEGV handler was installed. */ +class alternate_signal_stack +{ +public: + alternate_signal_stack () + { +#ifdef HAVE_SIGALTSTACK + m_stack.reset ((char *) xmalloc (SIGSTKSZ)); + + stack_t stack; + stack.ss_sp = m_stack.get (); + stack.ss_size = SIGSTKSZ; + stack.ss_flags = 0; + + sigaltstack (&stack, &m_old_stack); +#endif + } + + ~alternate_signal_stack () + { +#ifdef HAVE_SIGALTSTACK + sigaltstack (&m_old_stack, nullptr); +#endif + } + + DISABLE_COPY_AND_ASSIGN (alternate_signal_stack); + +private: + +#ifdef HAVE_SIGALTSTACK + gdb::unique_xmalloc_ptr<char> m_stack; + stack_t m_old_stack; +#endif +}; + +} + +#endif /* GDBSUPPORT_ALT_STACK_H */ @@ -52,6 +52,7 @@ #ifdef GDBTK #include "gdbtk/generic/gdbtk.h" #endif +#include "gdbsupport/alt-stack.h" /* The selected interpreter. This will be used as a set command variable, so it should always be malloc'ed - since @@ -334,29 +335,6 @@ get_init_files (std::vector<std::string> *system_gdbinit, *local_gdbinit = localinit; } -/* Try to set up an alternate signal stack for SIGSEGV handlers. - This allows us to handle SIGSEGV signals generated when the - normal process stack is exhausted. If this stack is not set - up (sigaltstack is unavailable or fails) and a SIGSEGV is - generated when the normal stack is exhausted then the program - will behave as though no SIGSEGV handler was installed. */ - -static void -setup_alternate_signal_stack (void) -{ -#ifdef HAVE_SIGALTSTACK - stack_t ss; - - /* FreeBSD versions older than 11.0 use char * for ss_sp instead of - void *. This cast works with both types. */ - ss.ss_sp = (char *) xmalloc (SIGSTKSZ); - ss.ss_size = SIGSTKSZ; - ss.ss_flags = 0; - - sigaltstack(&ss, NULL); -#endif -} - /* Call command_loop. */ /* Prevent inlining this function for the benefit of GDB's selftests @@ -898,7 +876,7 @@ captured_main_1 (struct captured_main_args *context) save_original_signals_state (quiet); /* Try to set up an alternate signal stack for SIGSEGV handlers. */ - setup_alternate_signal_stack (); + gdb::alternate_signal_stack signal_stack; /* Initialize all files. */ gdb_init (gdb_program_name); |