/* Target-dependent code for GNU/Linux running on i386's, for GDB.
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/* Target-dependent code for GNU/Linux running on i386's, for GDB.
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|
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Copyright 2000, 2001, 2002 Free Software Foundation, Inc.
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Copyright 2000, 2001, 2002 Free Software Foundation, Inc.
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|
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This file is part of GDB.
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This file is part of GDB.
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|
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This program is free software; you can redistribute it and/or modify
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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(at your option) any later version.
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|
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This program is distributed in the hope that it will be useful,
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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GNU General Public License for more details.
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|
|
You should have received a copy of the GNU General Public License
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You should have received a copy of the GNU General Public License
|
along with this program; if not, write to the Free Software
|
along with this program; if not, write to the Free Software
|
Foundation, Inc., 59 Temple Place - Suite 330,
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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Boston, MA 02111-1307, USA. */
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|
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#include "defs.h"
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#include "defs.h"
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#include "gdbcore.h"
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#include "gdbcore.h"
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#include "frame.h"
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#include "frame.h"
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#include "value.h"
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#include "value.h"
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#include "regcache.h"
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#include "regcache.h"
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#include "inferior.h"
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#include "inferior.h"
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/* For i386_linux_skip_solib_resolver. */
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/* For i386_linux_skip_solib_resolver. */
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#include "symtab.h"
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#include "symtab.h"
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#include "symfile.h"
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#include "symfile.h"
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#include "objfiles.h"
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#include "objfiles.h"
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|
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#include "solib-svr4.h" /* For struct link_map_offsets. */
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#include "solib-svr4.h" /* For struct link_map_offsets. */
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|
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#include "i386-tdep.h"
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#include "i386-tdep.h"
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#include "i386-linux-tdep.h"
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#include "i386-linux-tdep.h"
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|
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/* Return the name of register REG. */
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/* Return the name of register REG. */
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static const char *
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static const char *
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i386_linux_register_name (int reg)
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i386_linux_register_name (int reg)
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{
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{
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/* Deal with the extra "orig_eax" pseudo register. */
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/* Deal with the extra "orig_eax" pseudo register. */
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if (reg == I386_LINUX_ORIG_EAX_REGNUM)
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if (reg == I386_LINUX_ORIG_EAX_REGNUM)
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return "orig_eax";
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return "orig_eax";
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return i386_register_name (reg);
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return i386_register_name (reg);
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}
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}
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/* Recognizing signal handler frames. */
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/* Recognizing signal handler frames. */
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|
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/* GNU/Linux has two flavors of signals. Normal signal handlers, and
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/* GNU/Linux has two flavors of signals. Normal signal handlers, and
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"realtime" (RT) signals. The RT signals can provide additional
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"realtime" (RT) signals. The RT signals can provide additional
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information to the signal handler if the SA_SIGINFO flag is set
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information to the signal handler if the SA_SIGINFO flag is set
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when establishing a signal handler using `sigaction'. It is not
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when establishing a signal handler using `sigaction'. It is not
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unlikely that future versions of GNU/Linux will support SA_SIGINFO
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unlikely that future versions of GNU/Linux will support SA_SIGINFO
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for normal signals too. */
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for normal signals too. */
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|
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/* When the i386 Linux kernel calls a signal handler and the
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/* When the i386 Linux kernel calls a signal handler and the
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SA_RESTORER flag isn't set, the return address points to a bit of
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SA_RESTORER flag isn't set, the return address points to a bit of
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code on the stack. This function returns whether the PC appears to
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code on the stack. This function returns whether the PC appears to
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be within this bit of code.
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be within this bit of code.
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The instruction sequence for normal signals is
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The instruction sequence for normal signals is
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pop %eax
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pop %eax
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mov $0x77,%eax
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mov $0x77,%eax
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int $0x80
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int $0x80
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or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
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or 0x58 0xb8 0x77 0x00 0x00 0x00 0xcd 0x80.
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|
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Checking for the code sequence should be somewhat reliable, because
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Checking for the code sequence should be somewhat reliable, because
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the effect is to call the system call sigreturn. This is unlikely
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the effect is to call the system call sigreturn. This is unlikely
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to occur anywhere other than a signal trampoline.
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to occur anywhere other than a signal trampoline.
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It kind of sucks that we have to read memory from the process in
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It kind of sucks that we have to read memory from the process in
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order to identify a signal trampoline, but there doesn't seem to be
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order to identify a signal trampoline, but there doesn't seem to be
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any other way. The PC_IN_SIGTRAMP macro in tm-linux.h arranges to
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any other way. The PC_IN_SIGTRAMP macro in tm-linux.h arranges to
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only call us if no function name could be identified, which should
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only call us if no function name could be identified, which should
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be the case since the code is on the stack.
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be the case since the code is on the stack.
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Detection of signal trampolines for handlers that set the
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Detection of signal trampolines for handlers that set the
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SA_RESTORER flag is in general not possible. Unfortunately this is
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SA_RESTORER flag is in general not possible. Unfortunately this is
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what the GNU C Library has been doing for quite some time now.
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what the GNU C Library has been doing for quite some time now.
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However, as of version 2.1.2, the GNU C Library uses signal
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However, as of version 2.1.2, the GNU C Library uses signal
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trampolines (named __restore and __restore_rt) that are identical
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trampolines (named __restore and __restore_rt) that are identical
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to the ones used by the kernel. Therefore, these trampolines are
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to the ones used by the kernel. Therefore, these trampolines are
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supported too. */
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supported too. */
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#define LINUX_SIGTRAMP_INSN0 (0x58) /* pop %eax */
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#define LINUX_SIGTRAMP_INSN0 (0x58) /* pop %eax */
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#define LINUX_SIGTRAMP_OFFSET0 (0)
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#define LINUX_SIGTRAMP_OFFSET0 (0)
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#define LINUX_SIGTRAMP_INSN1 (0xb8) /* mov $NNNN,%eax */
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#define LINUX_SIGTRAMP_INSN1 (0xb8) /* mov $NNNN,%eax */
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#define LINUX_SIGTRAMP_OFFSET1 (1)
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#define LINUX_SIGTRAMP_OFFSET1 (1)
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#define LINUX_SIGTRAMP_INSN2 (0xcd) /* int */
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#define LINUX_SIGTRAMP_INSN2 (0xcd) /* int */
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#define LINUX_SIGTRAMP_OFFSET2 (6)
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#define LINUX_SIGTRAMP_OFFSET2 (6)
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static const unsigned char linux_sigtramp_code[] =
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static const unsigned char linux_sigtramp_code[] =
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{
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{
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LINUX_SIGTRAMP_INSN0, /* pop %eax */
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LINUX_SIGTRAMP_INSN0, /* pop %eax */
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LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77,%eax */
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LINUX_SIGTRAMP_INSN1, 0x77, 0x00, 0x00, 0x00, /* mov $0x77,%eax */
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LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */
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LINUX_SIGTRAMP_INSN2, 0x80 /* int $0x80 */
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};
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};
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#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
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#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code)
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/* If PC is in a sigtramp routine, return the address of the start of
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/* If PC is in a sigtramp routine, return the address of the start of
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the routine. Otherwise, return 0. */
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the routine. Otherwise, return 0. */
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static CORE_ADDR
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static CORE_ADDR
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i386_linux_sigtramp_start (CORE_ADDR pc)
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i386_linux_sigtramp_start (CORE_ADDR pc)
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{
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{
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unsigned char buf[LINUX_SIGTRAMP_LEN];
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unsigned char buf[LINUX_SIGTRAMP_LEN];
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|
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/* We only recognize a signal trampoline if PC is at the start of
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/* We only recognize a signal trampoline if PC is at the start of
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one of the three instructions. We optimize for finding the PC at
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one of the three instructions. We optimize for finding the PC at
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the start, as will be the case when the trampoline is not the
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the start, as will be the case when the trampoline is not the
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first frame on the stack. We assume that in the case where the
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first frame on the stack. We assume that in the case where the
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PC is not at the start of the instruction sequence, there will be
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PC is not at the start of the instruction sequence, there will be
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a few trailing readable bytes on the stack. */
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a few trailing readable bytes on the stack. */
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if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
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if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
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return 0;
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return 0;
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if (buf[0] != LINUX_SIGTRAMP_INSN0)
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if (buf[0] != LINUX_SIGTRAMP_INSN0)
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{
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{
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int adjust;
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int adjust;
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switch (buf[0])
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switch (buf[0])
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{
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{
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case LINUX_SIGTRAMP_INSN1:
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case LINUX_SIGTRAMP_INSN1:
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adjust = LINUX_SIGTRAMP_OFFSET1;
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adjust = LINUX_SIGTRAMP_OFFSET1;
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break;
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break;
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case LINUX_SIGTRAMP_INSN2:
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case LINUX_SIGTRAMP_INSN2:
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adjust = LINUX_SIGTRAMP_OFFSET2;
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adjust = LINUX_SIGTRAMP_OFFSET2;
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break;
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break;
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default:
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default:
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return 0;
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return 0;
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}
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}
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pc -= adjust;
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pc -= adjust;
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if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
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if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0)
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return 0;
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return 0;
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}
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}
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if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
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if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0)
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return 0;
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return 0;
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return pc;
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return pc;
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}
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}
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/* This function does the same for RT signals. Here the instruction
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/* This function does the same for RT signals. Here the instruction
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sequence is
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sequence is
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mov $0xad,%eax
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mov $0xad,%eax
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int $0x80
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int $0x80
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or 0xb8 0xad 0x00 0x00 0x00 0xcd 0x80.
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or 0xb8 0xad 0x00 0x00 0x00 0xcd 0x80.
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The effect is to call the system call rt_sigreturn. */
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The effect is to call the system call rt_sigreturn. */
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#define LINUX_RT_SIGTRAMP_INSN0 (0xb8) /* mov $NNNN,%eax */
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#define LINUX_RT_SIGTRAMP_INSN0 (0xb8) /* mov $NNNN,%eax */
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#define LINUX_RT_SIGTRAMP_OFFSET0 (0)
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#define LINUX_RT_SIGTRAMP_OFFSET0 (0)
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#define LINUX_RT_SIGTRAMP_INSN1 (0xcd) /* int */
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#define LINUX_RT_SIGTRAMP_INSN1 (0xcd) /* int */
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#define LINUX_RT_SIGTRAMP_OFFSET1 (5)
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#define LINUX_RT_SIGTRAMP_OFFSET1 (5)
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|
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static const unsigned char linux_rt_sigtramp_code[] =
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static const unsigned char linux_rt_sigtramp_code[] =
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{
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{
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LINUX_RT_SIGTRAMP_INSN0, 0xad, 0x00, 0x00, 0x00, /* mov $0xad,%eax */
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LINUX_RT_SIGTRAMP_INSN0, 0xad, 0x00, 0x00, 0x00, /* mov $0xad,%eax */
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LINUX_RT_SIGTRAMP_INSN1, 0x80 /* int $0x80 */
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LINUX_RT_SIGTRAMP_INSN1, 0x80 /* int $0x80 */
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};
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};
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#define LINUX_RT_SIGTRAMP_LEN (sizeof linux_rt_sigtramp_code)
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#define LINUX_RT_SIGTRAMP_LEN (sizeof linux_rt_sigtramp_code)
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/* If PC is in a RT sigtramp routine, return the address of the start
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/* If PC is in a RT sigtramp routine, return the address of the start
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of the routine. Otherwise, return 0. */
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of the routine. Otherwise, return 0. */
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static CORE_ADDR
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static CORE_ADDR
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i386_linux_rt_sigtramp_start (CORE_ADDR pc)
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i386_linux_rt_sigtramp_start (CORE_ADDR pc)
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{
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{
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unsigned char buf[LINUX_RT_SIGTRAMP_LEN];
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unsigned char buf[LINUX_RT_SIGTRAMP_LEN];
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|
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/* We only recognize a signal trampoline if PC is at the start of
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/* We only recognize a signal trampoline if PC is at the start of
|
one of the two instructions. We optimize for finding the PC at
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one of the two instructions. We optimize for finding the PC at
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the start, as will be the case when the trampoline is not the
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the start, as will be the case when the trampoline is not the
|
first frame on the stack. We assume that in the case where the
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first frame on the stack. We assume that in the case where the
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PC is not at the start of the instruction sequence, there will be
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PC is not at the start of the instruction sequence, there will be
|
a few trailing readable bytes on the stack. */
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a few trailing readable bytes on the stack. */
|
|
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if (read_memory_nobpt (pc, (char *) buf, LINUX_RT_SIGTRAMP_LEN) != 0)
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if (read_memory_nobpt (pc, (char *) buf, LINUX_RT_SIGTRAMP_LEN) != 0)
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return 0;
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return 0;
|
|
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if (buf[0] != LINUX_RT_SIGTRAMP_INSN0)
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if (buf[0] != LINUX_RT_SIGTRAMP_INSN0)
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{
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{
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if (buf[0] != LINUX_RT_SIGTRAMP_INSN1)
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if (buf[0] != LINUX_RT_SIGTRAMP_INSN1)
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return 0;
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return 0;
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|
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pc -= LINUX_RT_SIGTRAMP_OFFSET1;
|
pc -= LINUX_RT_SIGTRAMP_OFFSET1;
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|
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if (read_memory_nobpt (pc, (char *) buf, LINUX_RT_SIGTRAMP_LEN) != 0)
|
if (read_memory_nobpt (pc, (char *) buf, LINUX_RT_SIGTRAMP_LEN) != 0)
|
return 0;
|
return 0;
|
}
|
}
|
|
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if (memcmp (buf, linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN) != 0)
|
if (memcmp (buf, linux_rt_sigtramp_code, LINUX_RT_SIGTRAMP_LEN) != 0)
|
return 0;
|
return 0;
|
|
|
return pc;
|
return pc;
|
}
|
}
|
|
|
/* Return whether PC is in a GNU/Linux sigtramp routine. */
|
/* Return whether PC is in a GNU/Linux sigtramp routine. */
|
|
|
static int
|
static int
|
i386_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
|
i386_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
|
{
|
{
|
if (name)
|
if (name)
|
return STREQ ("__restore", name) || STREQ ("__restore_rt", name);
|
return STREQ ("__restore", name) || STREQ ("__restore_rt", name);
|
|
|
return (i386_linux_sigtramp_start (pc) != 0
|
return (i386_linux_sigtramp_start (pc) != 0
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|| i386_linux_rt_sigtramp_start (pc) != 0);
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|| i386_linux_rt_sigtramp_start (pc) != 0);
|
}
|
}
|
|
|
/* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
|
/* Assuming FRAME is for a GNU/Linux sigtramp routine, return the
|
address of the associated sigcontext structure. */
|
address of the associated sigcontext structure. */
|
|
|
static CORE_ADDR
|
static CORE_ADDR
|
i386_linux_sigcontext_addr (struct frame_info *frame)
|
i386_linux_sigcontext_addr (struct frame_info *frame)
|
{
|
{
|
CORE_ADDR pc;
|
CORE_ADDR pc;
|
|
|
pc = i386_linux_sigtramp_start (frame->pc);
|
pc = i386_linux_sigtramp_start (frame->pc);
|
if (pc)
|
if (pc)
|
{
|
{
|
CORE_ADDR sp;
|
CORE_ADDR sp;
|
|
|
if (frame->next)
|
if (frame->next)
|
/* If this isn't the top frame, the next frame must be for the
|
/* If this isn't the top frame, the next frame must be for the
|
signal handler itself. The sigcontext structure lives on
|
signal handler itself. The sigcontext structure lives on
|
the stack, right after the signum argument. */
|
the stack, right after the signum argument. */
|
return frame->next->frame + 12;
|
return frame->next->frame + 12;
|
|
|
/* This is the top frame. We'll have to find the address of the
|
/* This is the top frame. We'll have to find the address of the
|
sigcontext structure by looking at the stack pointer. Keep
|
sigcontext structure by looking at the stack pointer. Keep
|
in mind that the first instruction of the sigtramp code is
|
in mind that the first instruction of the sigtramp code is
|
"pop %eax". If the PC is at this instruction, adjust the
|
"pop %eax". If the PC is at this instruction, adjust the
|
returned value accordingly. */
|
returned value accordingly. */
|
sp = read_register (SP_REGNUM);
|
sp = read_register (SP_REGNUM);
|
if (pc == frame->pc)
|
if (pc == frame->pc)
|
return sp + 4;
|
return sp + 4;
|
return sp;
|
return sp;
|
}
|
}
|
|
|
pc = i386_linux_rt_sigtramp_start (frame->pc);
|
pc = i386_linux_rt_sigtramp_start (frame->pc);
|
if (pc)
|
if (pc)
|
{
|
{
|
if (frame->next)
|
if (frame->next)
|
/* If this isn't the top frame, the next frame must be for the
|
/* If this isn't the top frame, the next frame must be for the
|
signal handler itself. The sigcontext structure is part of
|
signal handler itself. The sigcontext structure is part of
|
the user context. A pointer to the user context is passed
|
the user context. A pointer to the user context is passed
|
as the third argument to the signal handler. */
|
as the third argument to the signal handler. */
|
return read_memory_integer (frame->next->frame + 16, 4) + 20;
|
return read_memory_integer (frame->next->frame + 16, 4) + 20;
|
|
|
/* This is the top frame. Again, use the stack pointer to find
|
/* This is the top frame. Again, use the stack pointer to find
|
the address of the sigcontext structure. */
|
the address of the sigcontext structure. */
|
return read_memory_integer (read_register (SP_REGNUM) + 8, 4) + 20;
|
return read_memory_integer (read_register (SP_REGNUM) + 8, 4) + 20;
|
}
|
}
|
|
|
error ("Couldn't recognize signal trampoline.");
|
error ("Couldn't recognize signal trampoline.");
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* Set the program counter for process PTID to PC. */
|
/* Set the program counter for process PTID to PC. */
|
|
|
static void
|
static void
|
i386_linux_write_pc (CORE_ADDR pc, ptid_t ptid)
|
i386_linux_write_pc (CORE_ADDR pc, ptid_t ptid)
|
{
|
{
|
write_register_pid (PC_REGNUM, pc, ptid);
|
write_register_pid (PC_REGNUM, pc, ptid);
|
|
|
/* We must be careful with modifying the program counter. If we
|
/* We must be careful with modifying the program counter. If we
|
just interrupted a system call, the kernel might try to restart
|
just interrupted a system call, the kernel might try to restart
|
it when we resume the inferior. On restarting the system call,
|
it when we resume the inferior. On restarting the system call,
|
the kernel will try backing up the program counter even though it
|
the kernel will try backing up the program counter even though it
|
no longer points at the system call. This typically results in a
|
no longer points at the system call. This typically results in a
|
SIGSEGV or SIGILL. We can prevent this by writing `-1' in the
|
SIGSEGV or SIGILL. We can prevent this by writing `-1' in the
|
"orig_eax" pseudo-register.
|
"orig_eax" pseudo-register.
|
|
|
Note that "orig_eax" is saved when setting up a dummy call frame.
|
Note that "orig_eax" is saved when setting up a dummy call frame.
|
This means that it is properly restored when that frame is
|
This means that it is properly restored when that frame is
|
popped, and that the interrupted system call will be restarted
|
popped, and that the interrupted system call will be restarted
|
when we resume the inferior on return from a function call from
|
when we resume the inferior on return from a function call from
|
within GDB. In all other cases the system call will not be
|
within GDB. In all other cases the system call will not be
|
restarted. */
|
restarted. */
|
write_register_pid (I386_LINUX_ORIG_EAX_REGNUM, -1, ptid);
|
write_register_pid (I386_LINUX_ORIG_EAX_REGNUM, -1, ptid);
|
}
|
}
|
|
|
/* Calling functions in shared libraries. */
|
/* Calling functions in shared libraries. */
|
|
|
/* Find the minimal symbol named NAME, and return both the minsym
|
/* Find the minimal symbol named NAME, and return both the minsym
|
struct and its objfile. This probably ought to be in minsym.c, but
|
struct and its objfile. This probably ought to be in minsym.c, but
|
everything there is trying to deal with things like C++ and
|
everything there is trying to deal with things like C++ and
|
SOFUN_ADDRESS_MAYBE_TURQUOISE, ... Since this is so simple, it may
|
SOFUN_ADDRESS_MAYBE_TURQUOISE, ... Since this is so simple, it may
|
be considered too special-purpose for general consumption. */
|
be considered too special-purpose for general consumption. */
|
|
|
static struct minimal_symbol *
|
static struct minimal_symbol *
|
find_minsym_and_objfile (char *name, struct objfile **objfile_p)
|
find_minsym_and_objfile (char *name, struct objfile **objfile_p)
|
{
|
{
|
struct objfile *objfile;
|
struct objfile *objfile;
|
|
|
ALL_OBJFILES (objfile)
|
ALL_OBJFILES (objfile)
|
{
|
{
|
struct minimal_symbol *msym;
|
struct minimal_symbol *msym;
|
|
|
ALL_OBJFILE_MSYMBOLS (objfile, msym)
|
ALL_OBJFILE_MSYMBOLS (objfile, msym)
|
{
|
{
|
if (SYMBOL_NAME (msym)
|
if (SYMBOL_NAME (msym)
|
&& STREQ (SYMBOL_NAME (msym), name))
|
&& STREQ (SYMBOL_NAME (msym), name))
|
{
|
{
|
*objfile_p = objfile;
|
*objfile_p = objfile;
|
return msym;
|
return msym;
|
}
|
}
|
}
|
}
|
}
|
}
|
|
|
return 0;
|
return 0;
|
}
|
}
|
|
|
static CORE_ADDR
|
static CORE_ADDR
|
skip_hurd_resolver (CORE_ADDR pc)
|
skip_hurd_resolver (CORE_ADDR pc)
|
{
|
{
|
/* The HURD dynamic linker is part of the GNU C library, so many
|
/* The HURD dynamic linker is part of the GNU C library, so many
|
GNU/Linux distributions use it. (All ELF versions, as far as I
|
GNU/Linux distributions use it. (All ELF versions, as far as I
|
know.) An unresolved PLT entry points to "_dl_runtime_resolve",
|
know.) An unresolved PLT entry points to "_dl_runtime_resolve",
|
which calls "fixup" to patch the PLT, and then passes control to
|
which calls "fixup" to patch the PLT, and then passes control to
|
the function.
|
the function.
|
|
|
We look for the symbol `_dl_runtime_resolve', and find `fixup' in
|
We look for the symbol `_dl_runtime_resolve', and find `fixup' in
|
the same objfile. If we are at the entry point of `fixup', then
|
the same objfile. If we are at the entry point of `fixup', then
|
we set a breakpoint at the return address (at the top of the
|
we set a breakpoint at the return address (at the top of the
|
stack), and continue.
|
stack), and continue.
|
|
|
It's kind of gross to do all these checks every time we're
|
It's kind of gross to do all these checks every time we're
|
called, since they don't change once the executable has gotten
|
called, since they don't change once the executable has gotten
|
started. But this is only a temporary hack --- upcoming versions
|
started. But this is only a temporary hack --- upcoming versions
|
of GNU/Linux will provide a portable, efficient interface for
|
of GNU/Linux will provide a portable, efficient interface for
|
debugging programs that use shared libraries. */
|
debugging programs that use shared libraries. */
|
|
|
struct objfile *objfile;
|
struct objfile *objfile;
|
struct minimal_symbol *resolver
|
struct minimal_symbol *resolver
|
= find_minsym_and_objfile ("_dl_runtime_resolve", &objfile);
|
= find_minsym_and_objfile ("_dl_runtime_resolve", &objfile);
|
|
|
if (resolver)
|
if (resolver)
|
{
|
{
|
struct minimal_symbol *fixup
|
struct minimal_symbol *fixup
|
= lookup_minimal_symbol ("fixup", NULL, objfile);
|
= lookup_minimal_symbol ("fixup", NULL, objfile);
|
|
|
if (fixup && SYMBOL_VALUE_ADDRESS (fixup) == pc)
|
if (fixup && SYMBOL_VALUE_ADDRESS (fixup) == pc)
|
return (SAVED_PC_AFTER_CALL (get_current_frame ()));
|
return (SAVED_PC_AFTER_CALL (get_current_frame ()));
|
}
|
}
|
|
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* See the comments for SKIP_SOLIB_RESOLVER at the top of infrun.c.
|
/* See the comments for SKIP_SOLIB_RESOLVER at the top of infrun.c.
|
This function:
|
This function:
|
1) decides whether a PLT has sent us into the linker to resolve
|
1) decides whether a PLT has sent us into the linker to resolve
|
a function reference, and
|
a function reference, and
|
2) if so, tells us where to set a temporary breakpoint that will
|
2) if so, tells us where to set a temporary breakpoint that will
|
trigger when the dynamic linker is done. */
|
trigger when the dynamic linker is done. */
|
|
|
CORE_ADDR
|
CORE_ADDR
|
i386_linux_skip_solib_resolver (CORE_ADDR pc)
|
i386_linux_skip_solib_resolver (CORE_ADDR pc)
|
{
|
{
|
CORE_ADDR result;
|
CORE_ADDR result;
|
|
|
/* Plug in functions for other kinds of resolvers here. */
|
/* Plug in functions for other kinds of resolvers here. */
|
result = skip_hurd_resolver (pc);
|
result = skip_hurd_resolver (pc);
|
if (result)
|
if (result)
|
return result;
|
return result;
|
|
|
return 0;
|
return 0;
|
}
|
}
|
|
|
/* Fetch (and possibly build) an appropriate link_map_offsets
|
/* Fetch (and possibly build) an appropriate link_map_offsets
|
structure for native GNU/Linux x86 targets using the struct offsets
|
structure for native GNU/Linux x86 targets using the struct offsets
|
defined in link.h (but without actual reference to that file).
|
defined in link.h (but without actual reference to that file).
|
|
|
This makes it possible to access GNU/Linux x86 shared libraries
|
This makes it possible to access GNU/Linux x86 shared libraries
|
from a GDB that was not built on an GNU/Linux x86 host (for cross
|
from a GDB that was not built on an GNU/Linux x86 host (for cross
|
debugging). */
|
debugging). */
|
|
|
static struct link_map_offsets *
|
static struct link_map_offsets *
|
i386_linux_svr4_fetch_link_map_offsets (void)
|
i386_linux_svr4_fetch_link_map_offsets (void)
|
{
|
{
|
static struct link_map_offsets lmo;
|
static struct link_map_offsets lmo;
|
static struct link_map_offsets *lmp = NULL;
|
static struct link_map_offsets *lmp = NULL;
|
|
|
if (lmp == NULL)
|
if (lmp == NULL)
|
{
|
{
|
lmp = &lmo;
|
lmp = &lmo;
|
|
|
lmo.r_debug_size = 8; /* The actual size is 20 bytes, but
|
lmo.r_debug_size = 8; /* The actual size is 20 bytes, but
|
this is all we need. */
|
this is all we need. */
|
lmo.r_map_offset = 4;
|
lmo.r_map_offset = 4;
|
lmo.r_map_size = 4;
|
lmo.r_map_size = 4;
|
|
|
lmo.link_map_size = 20; /* The actual size is 552 bytes, but
|
lmo.link_map_size = 20; /* The actual size is 552 bytes, but
|
this is all we need. */
|
this is all we need. */
|
lmo.l_addr_offset = 0;
|
lmo.l_addr_offset = 0;
|
lmo.l_addr_size = 4;
|
lmo.l_addr_size = 4;
|
|
|
lmo.l_name_offset = 4;
|
lmo.l_name_offset = 4;
|
lmo.l_name_size = 4;
|
lmo.l_name_size = 4;
|
|
|
lmo.l_next_offset = 12;
|
lmo.l_next_offset = 12;
|
lmo.l_next_size = 4;
|
lmo.l_next_size = 4;
|
|
|
lmo.l_prev_offset = 16;
|
lmo.l_prev_offset = 16;
|
lmo.l_prev_size = 4;
|
lmo.l_prev_size = 4;
|
}
|
}
|
|
|
return lmp;
|
return lmp;
|
}
|
}
|
|
|
|
|
static void
|
static void
|
i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
|
i386_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
|
{
|
{
|
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
|
|
|
/* GNU/Linux uses ELF. */
|
/* GNU/Linux uses ELF. */
|
i386_elf_init_abi (info, gdbarch);
|
i386_elf_init_abi (info, gdbarch);
|
|
|
/* We support the SSE registers on GNU/Linux. */
|
/* We support the SSE registers on GNU/Linux. */
|
tdep->num_xmm_regs = I386_NUM_XREGS - 1;
|
tdep->num_xmm_regs = I386_NUM_XREGS - 1;
|
/* set_gdbarch_num_regs (gdbarch, I386_SSE_NUM_REGS); */
|
/* set_gdbarch_num_regs (gdbarch, I386_SSE_NUM_REGS); */
|
|
|
/* Since we have the extra "orig_eax" register on GNU/Linux, we have
|
/* Since we have the extra "orig_eax" register on GNU/Linux, we have
|
to adjust a few things. */
|
to adjust a few things. */
|
|
|
set_gdbarch_write_pc (gdbarch, i386_linux_write_pc);
|
set_gdbarch_write_pc (gdbarch, i386_linux_write_pc);
|
set_gdbarch_num_regs (gdbarch, I386_SSE_NUM_REGS + 1);
|
set_gdbarch_num_regs (gdbarch, I386_SSE_NUM_REGS + 1);
|
set_gdbarch_register_name (gdbarch, i386_linux_register_name);
|
set_gdbarch_register_name (gdbarch, i386_linux_register_name);
|
set_gdbarch_register_bytes (gdbarch, I386_SSE_SIZEOF_REGS + 4);
|
set_gdbarch_register_bytes (gdbarch, I386_SSE_SIZEOF_REGS + 4);
|
|
|
tdep->jb_pc_offset = 20; /* From <bits/setjmp.h>. */
|
tdep->jb_pc_offset = 20; /* From <bits/setjmp.h>. */
|
|
|
tdep->sigcontext_addr = i386_linux_sigcontext_addr;
|
tdep->sigcontext_addr = i386_linux_sigcontext_addr;
|
tdep->sc_pc_offset = 14 * 4; /* From <asm/sigcontext.h>. */
|
tdep->sc_pc_offset = 14 * 4; /* From <asm/sigcontext.h>. */
|
tdep->sc_sp_offset = 7 * 4;
|
tdep->sc_sp_offset = 7 * 4;
|
|
|
/* When the i386 Linux kernel calls a signal handler, the return
|
/* When the i386 Linux kernel calls a signal handler, the return
|
address points to a bit of code on the stack. This function is
|
address points to a bit of code on the stack. This function is
|
used to identify this bit of code as a signal trampoline in order
|
used to identify this bit of code as a signal trampoline in order
|
to support backtracing through calls to signal handlers. */
|
to support backtracing through calls to signal handlers. */
|
set_gdbarch_pc_in_sigtramp (gdbarch, i386_linux_pc_in_sigtramp);
|
set_gdbarch_pc_in_sigtramp (gdbarch, i386_linux_pc_in_sigtramp);
|
|
|
set_solib_svr4_fetch_link_map_offsets (gdbarch,
|
set_solib_svr4_fetch_link_map_offsets (gdbarch,
|
i386_linux_svr4_fetch_link_map_offsets);
|
i386_linux_svr4_fetch_link_map_offsets);
|
}
|
}
|
|
|
/* Provide a prototype to silence -Wmissing-prototypes. */
|
/* Provide a prototype to silence -Wmissing-prototypes. */
|
extern void _initialize_i386_linux_tdep (void);
|
extern void _initialize_i386_linux_tdep (void);
|
|
|
void
|
void
|
_initialize_i386_linux_tdep (void)
|
_initialize_i386_linux_tdep (void)
|
{
|
{
|
gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_LINUX,
|
gdbarch_register_osabi (bfd_arch_i386, GDB_OSABI_LINUX,
|
i386_linux_init_abi);
|
i386_linux_init_abi);
|
}
|
}
|
|
|
