old-cross-binutils/gdb/nat/linux-ptrace.h
Antoine Tremblay c9587f8823 Fix non executable stack handling when calling functions in the inferior.
When gdb creates a dummy frame to execute a function in the inferior,
the process may generate a SIGSEGV, SIGTRAP or SIGILL because the stack
is non executable. If the signal handler set in gdb has option print
or stop enabled for these signals gdb handles this correctly.

However, in the case of noprint and nostop the signal is short-circuited
and the inferior process is sent the signal directly. This causes the
inferior to crash because of gdb.

This patch adds a check for SIGSEGV, SIGTRAP or SIGILL so that these
signals are sent to gdb rather than short-circuited in the inferior.
gdb then handles them properly and the inferior process does not
crash.

This patch also fixes the same behavior in gdbserver.

Also added a small testcase to test the issue called catch-gdb-caused-signals.

This applies to Linux only, tested on Linux.

gdb/ChangeLog:
	PR breakpoints/16812
	* linux-nat.c (linux_nat_filter_event): Report SIGTRAP,SIGILL,SIGSEGV.
	* nat/linux-ptrace.c (linux_wstatus_maybe_breakpoint): Add.
	* nat/linux-ptrace.h: Add linux_wstatus_maybe_breakpoint.

gdb/gdbserver/ChangeLog:
	PR breakpoints/16812
	* linux-low.c (wstatus_maybe_breakpoint): Remove.
	(linux_low_filter_event): Update wstatus_maybe_breakpoint name.
	(linux_wait_1): Report SIGTRAP,SIGILL,SIGSEGV.

gdb/testsuite/ChangeLog:
	PR breakpoints/16812
	* gdb.base/catch-gdb-caused-signals.c: New file.
	* gdb.base/catch-gdb-caused-signals.exp: New file.
2015-02-19 11:04:21 -05:00

112 lines
3.6 KiB
C

/* Copyright (C) 2011-2015 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 COMMON_LINUX_PTRACE_H
#define COMMON_LINUX_PTRACE_H
struct buffer;
#include <sys/ptrace.h>
#ifdef __UCLIBC__
#if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
/* PTRACE_TEXT_ADDR and friends. */
#include <asm/ptrace.h>
#define HAS_NOMMU
#endif
#endif
#if !defined(PTRACE_TYPE_ARG3)
#define PTRACE_TYPE_ARG3 void *
#endif
#if !defined(PTRACE_TYPE_ARG4)
#define PTRACE_TYPE_ARG4 void *
#endif
#ifndef PTRACE_GETSIGINFO
# define PTRACE_GETSIGINFO 0x4202
# define PTRACE_SETSIGINFO 0x4203
#endif /* PTRACE_GETSIGINF */
/* If the system headers did not provide the constants, hard-code the normal
values. */
#ifndef PTRACE_EVENT_FORK
#define PTRACE_SETOPTIONS 0x4200
#define PTRACE_GETEVENTMSG 0x4201
/* options set using PTRACE_SETOPTIONS */
#define PTRACE_O_TRACESYSGOOD 0x00000001
#define PTRACE_O_TRACEFORK 0x00000002
#define PTRACE_O_TRACEVFORK 0x00000004
#define PTRACE_O_TRACECLONE 0x00000008
#define PTRACE_O_TRACEEXEC 0x00000010
#define PTRACE_O_TRACEVFORKDONE 0x00000020
#define PTRACE_O_TRACEEXIT 0x00000040
/* Wait extended result codes for the above trace options. */
#define PTRACE_EVENT_FORK 1
#define PTRACE_EVENT_VFORK 2
#define PTRACE_EVENT_CLONE 3
#define PTRACE_EVENT_EXEC 4
#define PTRACE_EVENT_VFORK_DONE 5
#define PTRACE_EVENT_EXIT 6
#endif /* PTRACE_EVENT_FORK */
#ifndef PTRACE_O_EXITKILL
/* Only defined in Linux Kernel 3.8 or later. */
#define PTRACE_O_EXITKILL 0x00100000
#endif
#if (defined __bfin__ || defined __frv__ || defined __sh__) \
&& !defined PTRACE_GETFDPIC
#define PTRACE_GETFDPIC 31
#define PTRACE_GETFDPIC_EXEC 0
#define PTRACE_GETFDPIC_INTERP 1
#endif
/* We can't always assume that this flag is available, but all systems
with the ptrace event handlers also have __WALL, so it's safe to use
in some contexts. */
#ifndef __WALL
#define __WALL 0x40000000 /* Wait for any child. */
#endif
extern void linux_ptrace_attach_fail_reason (pid_t pid, struct buffer *buffer);
/* Find all possible reasons we could have failed to attach to PTID
and return them as a string. ERR is the error PTRACE_ATTACH failed
with (an errno). The result is stored in a static buffer. This
string should be copied into a buffer by the client if the string
will not be immediately used, or if it must persist. */
extern char *linux_ptrace_attach_fail_reason_string (ptid_t ptid, int err);
extern void linux_ptrace_init_warnings (void);
extern void linux_enable_event_reporting (pid_t pid, int attached);
extern void linux_disable_event_reporting (pid_t pid);
extern int linux_supports_tracefork (void);
extern int linux_supports_traceclone (void);
extern int linux_supports_tracevforkdone (void);
extern int linux_supports_tracesysgood (void);
extern void linux_ptrace_set_additional_flags (int);
extern int linux_ptrace_get_extended_event (int wstat);
extern int linux_is_extended_waitstatus (int wstat);
extern int linux_wstatus_maybe_breakpoint (int wstat);
#endif /* COMMON_LINUX_PTRACE_H */