--- /dev/null
+/* Target-dependent code for OpenBSD/vax.
+
+ Copyright 2005 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 "arch-utils.h"
+#include "frame.h"
+#include "frame-unwind.h"
+#include "osabi.h"
+#include "symtab.h"
+#include "trad-frame.h"
+
+#include "vax-tdep.h"
+
+#include "gdb_string.h"
+
+/* Signal trampolines. */
+
+/* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page
+ in virtual memory. The randomness makes it somewhat tricky to
+ detect it, but fortunately we can rely on the fact that the start
+ of the sigtramp routine is page-aligned. We recognize the
+ trampoline by looking for the code that invokes the sigreturn
+ system call. The offset where we can find that code varies from
+ release to release.
+
+ By the way, the mapping mentioned above is read-only, so you cannot
+ place a breakpoint in the signal trampoline. */
+
+/* Default page size. */
+static const int vaxobsd_page_size = 4096;
+
+/* Offset for sigreturn(2). */
+static const int vaxobsd_sigreturn_offset = 0x11;
+
+/* Instruction sequence for sigreturn(2). VAX doesn't have
+ fixed-length instructions so we include the ensuing exit(2) to
+ reduce the chance of spurious matches. */
+static const gdb_byte vaxobsd_sigreturn[] = {
+ 0xbc, 0x8f, 0x67, 0x00, /* chmk $SYS_sigreturn */
+ 0xbc, 0x01 /* chmk $SYS_exit */
+};
+
+static int
+vaxobsd_sigtramp_p (struct frame_info *next_frame)
+{
+ CORE_ADDR pc = frame_pc_unwind (next_frame);
+ CORE_ADDR start_pc = (pc & ~(vaxobsd_page_size - 1));
+ CORE_ADDR sigreturn_addr = start_pc + vaxobsd_sigreturn_offset;
+ gdb_byte *buf;
+ char *name;
+
+ find_pc_partial_function (pc, &name, NULL, NULL);
+ if (name)
+ return 0;
+
+ buf = alloca(sizeof vaxobsd_sigreturn);
+ if (!safe_frame_unwind_memory (next_frame, sigreturn_addr,
+ buf, sizeof vaxobsd_sigreturn))
+ return 0;
+
+ if (memcmp(buf, vaxobsd_sigreturn, sizeof vaxobsd_sigreturn) == 0)
+ return 1;
+
+ return 0;
+}
+
+static struct trad_frame_cache *
+vaxobsd_sigtramp_frame_cache (struct frame_info *next_frame, void **this_cache)
+{
+ struct trad_frame_cache *cache;
+ CORE_ADDR addr, base, func;
+
+ if (*this_cache)
+ return *this_cache;
+
+ cache = trad_frame_cache_zalloc (next_frame);
+ *this_cache = cache;
+
+ func = frame_pc_unwind (next_frame);
+ func &= ~(vaxobsd_page_size - 1);
+
+ base = frame_unwind_register_unsigned (next_frame, VAX_SP_REGNUM);
+ addr = get_frame_memory_unsigned (next_frame, base - 4, 4);
+
+ trad_frame_set_reg_addr (cache, VAX_SP_REGNUM, addr + 8);
+ trad_frame_set_reg_addr (cache, VAX_FP_REGNUM, addr + 12);
+ trad_frame_set_reg_addr (cache, VAX_AP_REGNUM, addr + 16);
+ trad_frame_set_reg_addr (cache, VAX_PC_REGNUM, addr + 20);
+ trad_frame_set_reg_addr (cache, VAX_PS_REGNUM, addr + 24);
+
+ /* Construct the frame ID using the function start. */
+ trad_frame_set_id (cache, frame_id_build (base, func));
+
+ return cache;
+}
+
+static void
+vaxobsd_sigtramp_frame_this_id (struct frame_info *next_frame,
+ void **this_cache, struct frame_id *this_id)
+{
+ struct trad_frame_cache *cache =
+ vaxobsd_sigtramp_frame_cache (next_frame, this_cache);
+
+ trad_frame_get_id (cache, this_id);
+}
+
+static void
+vaxobsd_sigtramp_frame_prev_register (struct frame_info *next_frame,
+ void **this_cache, int regnum,
+ int *optimizedp, enum lval_type *lvalp,
+ CORE_ADDR *addrp, int *realnump,
+ gdb_byte *valuep)
+{
+ struct trad_frame_cache *cache =
+ vaxobsd_sigtramp_frame_cache (next_frame, this_cache);
+
+ trad_frame_get_register (cache, next_frame, regnum,
+ optimizedp, lvalp, addrp, realnump, valuep);
+}
+
+static const struct frame_unwind vaxobsd_sigtramp_frame_unwind = {
+ SIGTRAMP_FRAME,
+ vaxobsd_sigtramp_frame_this_id,
+ vaxobsd_sigtramp_frame_prev_register
+};
+
+static const struct frame_unwind *
+vaxobsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
+{
+ if (vaxobsd_sigtramp_p (next_frame))
+ return &vaxobsd_sigtramp_frame_unwind;
+
+ return NULL;
+}
+\f
+
+/* OpenBSD a.out. */
+
+static void
+vaxobsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+ frame_unwind_append_sniffer (gdbarch, vaxobsd_sigtramp_frame_sniffer);
+}
+
+/* FIXME: kettenis/20050821: Since OpenBSD/vax binaries are
+ indistingushable from NetBSD/vax a.out binaries, building a GDB
+ that should support both these targets will probably not work as
+ expected. */
+#define GDB_OSABI_OPENBSD_AOUT GDB_OSABI_NETBSD_AOUT
+
+static enum gdb_osabi
+vaxobsd_aout_osabi_sniffer (bfd *abfd)
+{
+ if (strcmp (bfd_get_target (abfd), "a.out-vax-netbsd") == 0)
+ return GDB_OSABI_OPENBSD_AOUT;
+
+ return GDB_OSABI_UNKNOWN;
+}
+\f
+
+/* Provide a prototype to silence -Wmissing-prototypes. */
+void _initialize_vaxobsd_tdep (void);
+
+void
+_initialize_vaxobsd_tdep (void)
+{
+ gdbarch_register_osabi_sniffer (bfd_arch_vax, bfd_target_aout_flavour,
+ vaxobsd_aout_osabi_sniffer);
+
+ gdbarch_register_osabi (bfd_arch_vax, 0, GDB_OSABI_OPENBSD_AOUT,
+ vaxobsd_init_abi);
+}
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