156 lines
4.2 KiB
C
156 lines
4.2 KiB
C
/* Target-dependent code for GNU/Linux on Alpha.
|
|
Copyright 2002, 2003 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 2 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, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place - Suite 330,
|
|
Boston, MA 02111-1307, USA. */
|
|
|
|
#include "defs.h"
|
|
#include "frame.h"
|
|
#include "gdb_assert.h"
|
|
#include "osabi.h"
|
|
#include "solib-svr4.h"
|
|
|
|
#include "alpha-tdep.h"
|
|
|
|
/* Under GNU/Linux, signal handler invocations can be identified by
|
|
the designated code sequence that is used to return from a signal
|
|
handler. In particular, the return address of a signal handler
|
|
points to a sequence that copies $sp to $16, loads $0 with the
|
|
appropriate syscall number, and finally enters the kernel.
|
|
|
|
This is somewhat complicated in that:
|
|
(1) the expansion of the "mov" assembler macro has changed over
|
|
time, from "bis src,src,dst" to "bis zero,src,dst",
|
|
(2) the kernel has changed from using "addq" to "lda" to load the
|
|
syscall number,
|
|
(3) there is a "normal" sigreturn and an "rt" sigreturn which
|
|
has a different stack layout.
|
|
*/
|
|
|
|
static long
|
|
alpha_linux_sigtramp_offset_1 (CORE_ADDR pc)
|
|
{
|
|
switch (alpha_read_insn (pc))
|
|
{
|
|
case 0x47de0410: /* bis $30,$30,$16 */
|
|
case 0x47fe0410: /* bis $31,$30,$16 */
|
|
return 0;
|
|
|
|
case 0x43ecf400: /* addq $31,103,$0 */
|
|
case 0x201f0067: /* lda $0,103($31) */
|
|
case 0x201f015f: /* lda $0,351($31) */
|
|
return 4;
|
|
|
|
case 0x00000083: /* call_pal callsys */
|
|
return 8;
|
|
|
|
default:
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
static LONGEST
|
|
alpha_linux_sigtramp_offset (CORE_ADDR pc)
|
|
{
|
|
long i, off;
|
|
|
|
if (pc & 3)
|
|
return -1;
|
|
|
|
/* Guess where we might be in the sequence. */
|
|
off = alpha_linux_sigtramp_offset_1 (pc);
|
|
if (off < 0)
|
|
return -1;
|
|
|
|
/* Verify that the other two insns of the sequence are as we expect. */
|
|
pc -= off;
|
|
for (i = 0; i < 12; i += 4)
|
|
{
|
|
if (i == off)
|
|
continue;
|
|
if (alpha_linux_sigtramp_offset_1 (pc + i) != i)
|
|
return -1;
|
|
}
|
|
|
|
return off;
|
|
}
|
|
|
|
static int
|
|
alpha_linux_pc_in_sigtramp (CORE_ADDR pc, char *func_name)
|
|
{
|
|
return alpha_linux_sigtramp_offset (pc) >= 0;
|
|
}
|
|
|
|
static CORE_ADDR
|
|
alpha_linux_sigcontext_addr (struct frame_info *next_frame)
|
|
{
|
|
CORE_ADDR pc;
|
|
ULONGEST sp;
|
|
long off;
|
|
|
|
pc = frame_pc_unwind (next_frame);
|
|
frame_unwind_unsigned_register (next_frame, ALPHA_SP_REGNUM, &sp);
|
|
|
|
off = alpha_linux_sigtramp_offset (pc);
|
|
gdb_assert (off >= 0);
|
|
|
|
/* __NR_rt_sigreturn has a couple of structures on the stack. This is:
|
|
|
|
struct rt_sigframe {
|
|
struct siginfo info;
|
|
struct ucontext uc;
|
|
};
|
|
|
|
offsetof (struct rt_sigframe, uc.uc_mcontext);
|
|
*/
|
|
if (alpha_read_insn (pc - off + 4) == 0x201f015f)
|
|
return sp + 176;
|
|
|
|
/* __NR_sigreturn has the sigcontext structure at the top of the stack. */
|
|
return sp;
|
|
}
|
|
|
|
static void
|
|
alpha_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
|
|
{
|
|
struct gdbarch_tdep *tdep;
|
|
|
|
/* Hook into the DWARF CFI frame unwinder. */
|
|
alpha_dwarf2_init_abi (info, gdbarch);
|
|
|
|
/* Hook into the MDEBUG frame unwinder. */
|
|
alpha_mdebug_init_abi (info, gdbarch);
|
|
|
|
tdep = gdbarch_tdep (gdbarch);
|
|
tdep->dynamic_sigtramp_offset = alpha_linux_sigtramp_offset;
|
|
tdep->sigcontext_addr = alpha_linux_sigcontext_addr;
|
|
tdep->pc_in_sigtramp = alpha_linux_pc_in_sigtramp;
|
|
tdep->jb_pc = 2;
|
|
tdep->jb_elt_size = 8;
|
|
|
|
/* Enable TLS support. */
|
|
set_gdbarch_fetch_tls_load_module_address (gdbarch,
|
|
svr4_fetch_objfile_link_map);
|
|
}
|
|
|
|
void
|
|
_initialize_alpha_linux_tdep (void)
|
|
{
|
|
gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_LINUX,
|
|
alpha_linux_init_abi);
|
|
}
|