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-rw-r--r--gdb/sparcobsd-tdep.c171
1 files changed, 171 insertions, 0 deletions
diff --git a/gdb/sparcobsd-tdep.c b/gdb/sparcobsd-tdep.c
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+++ b/gdb/sparcobsd-tdep.c
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+/* Target-dependent code for OpenBSD/sparc.
+
+ Copyright 2004 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 "floatformat.h"
+#include "frame.h"
+#include "frame-unwind.h"
+#include "osabi.h"
+#include "solib-svr4.h"
+#include "symtab.h"
+#include "trad-frame.h"
+
+#include "gdb_assert.h"
+
+#include "sparc-tdep.h"
+#include "nbsd-tdep.h"
+
+/* Signal trampolines. */
+
+/* The OpenBSD kernel maps the signal trampoline at some random
+ location in user space, which means that the traditional BSD way of
+ detecting it won't work.
+
+ The signal trampoline will be mapped at an address that is page
+ aligned. We recognize the signal trampoline by the looking for the
+ sigreturn system call. */
+
+static const int sparc32obsd_page_size = 4096;
+
+static int
+sparc32obsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
+{
+ CORE_ADDR start_pc = (pc & ~(sparc32obsd_page_size - 1));
+ unsigned long insn;
+
+ if (name)
+ return 0;
+
+ /* Check for "restore %g0, SYS_sigreturn, %g1". */
+ insn = sparc_fetch_instruction (start_pc + 0xec);
+ if (insn != 0x83e82067)
+ return 0;
+
+ /* Check for "t ST_SYSCALL". */
+ insn = sparc_fetch_instruction (start_pc + 0xf4);
+ if (insn != 0x91d02000)
+ return 0;
+
+ return 1;
+}
+
+static struct sparc_frame_cache *
+sparc32obsd_frame_cache (struct frame_info *next_frame, void **this_cache)
+{
+ struct sparc_frame_cache *cache;
+ CORE_ADDR addr;
+
+ if (*this_cache)
+ return *this_cache;
+
+ cache = sparc_frame_cache (next_frame, this_cache);
+ gdb_assert (cache == *this_cache);
+
+ /* If we couldn't find the frame's function, we're probably dealing
+ with an on-stack signal trampoline. */
+ if (cache->pc == 0)
+ {
+ cache->pc = frame_pc_unwind (next_frame);
+ cache->pc &= ~(sparc32obsd_page_size - 1);
+
+ /* Since we couldn't find the frame's function, the cache was
+ initialized under the assumption that we're frameless. */
+ cache->frameless_p = 0;
+ addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM);
+ cache->base = addr;
+ }
+
+ cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (next_frame);
+
+ return cache;
+}
+
+static void
+sparc32obsd_frame_this_id (struct frame_info *next_frame, void **this_cache,
+ struct frame_id *this_id)
+{
+ struct sparc_frame_cache *cache =
+ sparc32obsd_frame_cache (next_frame, this_cache);
+
+ (*this_id) = frame_id_build (cache->base, cache->pc);
+}
+
+static void
+sparc32obsd_frame_prev_register (struct frame_info *next_frame,
+ void **this_cache,
+ int regnum, int *optimizedp,
+ enum lval_type *lvalp, CORE_ADDR *addrp,
+ int *realnump, void *valuep)
+{
+ struct sparc_frame_cache *cache =
+ sparc32obsd_frame_cache (next_frame, this_cache);
+
+ trad_frame_prev_register (next_frame, cache->saved_regs, regnum,
+ optimizedp, lvalp, addrp, realnump, valuep);
+}
+
+static const struct frame_unwind sparc32obsd_frame_unwind =
+{
+ SIGTRAMP_FRAME,
+ sparc32obsd_frame_this_id,
+ sparc32obsd_frame_prev_register
+};
+
+static const struct frame_unwind *
+sparc32obsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
+{
+ CORE_ADDR pc = frame_pc_unwind (next_frame);
+ char *name;
+
+ find_pc_partial_function (pc, &name, NULL, NULL);
+ if (sparc32obsd_pc_in_sigtramp (pc, name))
+ return &sparc32obsd_frame_unwind;
+
+ return NULL;
+}
+
+
+static void
+sparc32obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ /* OpenBSD doesn't support the 128-bit `long double' from the psABI. */
+ set_gdbarch_long_double_bit (gdbarch, 64);
+ set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big);
+
+ set_gdbarch_pc_in_sigtramp (gdbarch, sparc32obsd_pc_in_sigtramp);
+ frame_unwind_append_sniffer (gdbarch, sparc32obsd_sigtramp_frame_sniffer);
+
+ set_solib_svr4_fetch_link_map_offsets
+ (gdbarch, nbsd_ilp32_solib_svr4_fetch_link_map_offsets);
+}
+
+
+/* Provide a prototype to silence -Wmissing-prototypes. */
+void _initialize_sparc32obsd_tdep (void);
+
+void
+_initialize_sparc32obsd_tdep (void)
+{
+ gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_OPENBSD_ELF,
+ sparc32obsd_init_abi);
+}