166 lines
4.5 KiB
C
166 lines
4.5 KiB
C
/* Target-dependent code for OpenBSD/sparc.
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Copyright 2004 Free Software Foundation, Inc.
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This file is part of GDB.
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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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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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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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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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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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along with this program; if not, write to the Free Software
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Foundation, Inc., 59 Temple Place - Suite 330,
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Boston, MA 02111-1307, USA. */
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#include "defs.h"
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#include "floatformat.h"
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#include "frame.h"
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#include "frame-unwind.h"
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#include "osabi.h"
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#include "solib-svr4.h"
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#include "symtab.h"
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#include "trad-frame.h"
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#include "gdb_assert.h"
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#include "sparc-tdep.h"
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/* Signal trampolines. */
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/* The OpenBSD kernel maps the signal trampoline at some random
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location in user space, which means that the traditional BSD way of
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detecting it won't work.
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The signal trampoline will be mapped at an address that is page
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aligned. We recognize the signal trampoline by the looking for the
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sigreturn system call. */
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static const int sparc32obsd_page_size = 4096;
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static int
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sparc32obsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
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{
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CORE_ADDR start_pc = (pc & ~(sparc32obsd_page_size - 1));
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unsigned long insn;
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if (name)
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return 0;
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/* Check for "restore %g0, SYS_sigreturn, %g1". */
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insn = sparc_fetch_instruction (start_pc + 0xec);
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if (insn != 0x83e82067)
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return 0;
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/* Check for "t ST_SYSCALL". */
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insn = sparc_fetch_instruction (start_pc + 0xf4);
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if (insn != 0x91d02000)
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return 0;
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return 1;
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}
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static struct sparc_frame_cache *
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sparc32obsd_frame_cache (struct frame_info *next_frame, void **this_cache)
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{
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struct sparc_frame_cache *cache;
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CORE_ADDR addr;
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if (*this_cache)
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return *this_cache;
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cache = sparc_frame_cache (next_frame, this_cache);
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gdb_assert (cache == *this_cache);
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/* If we couldn't find the frame's function, we're probably dealing
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with an on-stack signal trampoline. */
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if (cache->pc == 0)
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{
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cache->pc = frame_pc_unwind (next_frame);
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cache->pc &= ~(sparc32obsd_page_size - 1);
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/* Since we couldn't find the frame's function, the cache was
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initialized under the assumption that we're frameless. */
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cache->frameless_p = 0;
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addr = frame_unwind_register_unsigned (next_frame, SPARC_FP_REGNUM);
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cache->base = addr;
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}
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cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (next_frame);
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return cache;
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}
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static void
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sparc32obsd_frame_this_id (struct frame_info *next_frame, void **this_cache,
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struct frame_id *this_id)
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{
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struct sparc_frame_cache *cache =
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sparc32obsd_frame_cache (next_frame, this_cache);
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(*this_id) = frame_id_build (cache->base, cache->pc);
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}
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static void
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sparc32obsd_frame_prev_register (struct frame_info *next_frame,
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void **this_cache,
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int regnum, int *optimizedp,
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enum lval_type *lvalp, CORE_ADDR *addrp,
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int *realnump, gdb_byte *valuep)
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{
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struct sparc_frame_cache *cache =
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sparc32obsd_frame_cache (next_frame, this_cache);
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trad_frame_get_prev_register (next_frame, cache->saved_regs, regnum,
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optimizedp, lvalp, addrp, realnump, valuep);
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}
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static const struct frame_unwind sparc32obsd_frame_unwind =
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{
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SIGTRAMP_FRAME,
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sparc32obsd_frame_this_id,
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sparc32obsd_frame_prev_register
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};
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static const struct frame_unwind *
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sparc32obsd_sigtramp_frame_sniffer (struct frame_info *next_frame)
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{
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CORE_ADDR pc = frame_pc_unwind (next_frame);
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char *name;
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find_pc_partial_function (pc, &name, NULL, NULL);
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if (sparc32obsd_pc_in_sigtramp (pc, name))
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return &sparc32obsd_frame_unwind;
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return NULL;
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}
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static void
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sparc32obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
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{
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struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
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/* OpenBSD/sparc is very similar to NetBSD/sparc ELF. */
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sparc32nbsd_elf_init_abi (info, gdbarch);
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frame_unwind_append_sniffer (gdbarch, sparc32obsd_sigtramp_frame_sniffer);
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}
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/* Provide a prototype to silence -Wmissing-prototypes. */
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void _initialize_sparc32obsd_tdep (void);
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void
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_initialize_sparc32obsd_tdep (void)
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{
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gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_OPENBSD_ELF,
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sparc32obsd_init_abi);
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}
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