--- /dev/null
+/* Target-dependent code for GNU/Linux on Alpha.
+ Copyright 2002 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 "value.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 the following sequence (the first instruction is quadword
+ aligned):
+
+ bis $30,$30,$16
+ addq $31,0x67,$0
+ call_pal callsys
+
+ Each instruction has a unique encoding, so we simply attempt to
+ match the instruction the pc is pointing to with any of the above
+ instructions. If there is a hit, we know the offset to the start
+ of the designated sequence and can then check whether we really are
+ executing in a designated sequence. If not, -1 is returned,
+ otherwise the offset from the start of the desingated sequence is
+ returned.
+
+ There is a slight chance of false hits: code could jump into the
+ middle of the designated sequence, in which case there is no
+ guarantee that we are in the middle of a sigreturn syscall. Don't
+ think this will be a problem in praxis, though. */
+long
+alpha_linux_sigtramp_offset (CORE_ADDR pc)
+{
+ unsigned int i[3], w;
+ long off;
+
+ if (read_memory_nobpt (pc, (char *) &w, 4) != 0)
+ return -1;
+
+ off = -1;
+ switch (w)
+ {
+ case 0x47de0410:
+ off = 0;
+ break; /* bis $30,$30,$16 */
+ case 0x43ecf400:
+ off = 4;
+ break; /* addq $31,0x67,$0 */
+ case 0x00000083:
+ off = 8;
+ break; /* call_pal callsys */
+ default:
+ return -1;
+ }
+ pc -= off;
+ if (pc & 0x7)
+ {
+ /* designated sequence is not quadword aligned */
+ return -1;
+ }
+ if (read_memory_nobpt (pc, (char *) i, sizeof (i)) != 0)
+ return -1;
+
+ if (i[0] == 0x47de0410 && i[1] == 0x43ecf400 && i[2] == 0x00000083)
+ return off;
+
+ return -1;
+}
+
+static void
+alpha_linux_init_abi (struct gdbarch_info info,
+ struct gdbarch *gdbarch)
+{
+ /* Place holder. */
+}
+
+void
+_initialize_alpha_linux_tdep (void)
+{
+ alpha_gdbarch_register_os_abi (ALPHA_ABI_LINUX, alpha_linux_init_abi);
+}
return (func_name != NULL && STREQ ("__sigtramp", func_name));
}
-/* 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 the following sequence (the first instruction is quadword
- aligned):
-
- bis $30,$30,$16
- addq $31,0x67,$0
- call_pal callsys
-
- Each instruction has a unique encoding, so we simply attempt to
- match the instruction the pc is pointing to with any of the above
- instructions. If there is a hit, we know the offset to the start
- of the designated sequence and can then check whether we really are
- executing in a designated sequence. If not, -1 is returned,
- otherwise the offset from the start of the desingated sequence is
- returned.
-
- There is a slight chance of false hits: code could jump into the
- middle of the designated sequence, in which case there is no
- guarantee that we are in the middle of a sigreturn syscall. Don't
- think this will be a problem in praxis, though.
- */
-
-#ifndef TM_LINUXALPHA_H
-/* HACK: Provide a prototype when compiling this file for non
- linuxalpha targets. */
-long alpha_linux_sigtramp_offset (CORE_ADDR pc);
-#endif
-long
-alpha_linux_sigtramp_offset (CORE_ADDR pc)
-{
- unsigned int i[3], w;
- long off;
-
- if (read_memory_nobpt (pc, (char *) &w, 4) != 0)
- return -1;
-
- off = -1;
- switch (w)
- {
- case 0x47de0410:
- off = 0;
- break; /* bis $30,$30,$16 */
- case 0x43ecf400:
- off = 4;
- break; /* addq $31,0x67,$0 */
- case 0x00000083:
- off = 8;
- break; /* call_pal callsys */
- default:
- return -1;
- }
- pc -= off;
- if (pc & 0x7)
- {
- /* designated sequence is not quadword aligned */
- return -1;
- }
-
- if (read_memory_nobpt (pc, (char *) i, sizeof (i)) != 0)
- return -1;
-
- if (i[0] == 0x47de0410 && i[1] == 0x43ecf400 && i[2] == 0x00000083)
- return off;
-
- return -1;
-}
-\f
-
/* Under OSF/1, the __sigtramp routine is frameless and has a frame
size of zero, but we are able to backtrace through it. */
CORE_ADDR
projects / deliverable / binutils-gdb.git / commitdiff
