| /* Target-dependent code for OpenBSD/sparc. |
| |
| Copyright (C) 2004-2021 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 3 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, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| #include "frame.h" |
| #include "frame-unwind.h" |
| #include "gdbcore.h" |
| #include "osabi.h" |
| #include "regcache.h" |
| #include "symtab.h" |
| #include "trad-frame.h" |
| #include "inferior.h" |
| |
| #include "obsd-tdep.h" |
| #include "sparc-tdep.h" |
| #include "solib-svr4.h" |
| #include "bsd-uthread.h" |
| #include "gdbarch.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 looking for the |
| sigreturn system call. */ |
| |
| static const int sparc32obsd_page_size = 4096; |
| |
| static int |
| sparc32obsd_pc_in_sigtramp (CORE_ADDR pc, const 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_sigtramp_frame_cache (struct frame_info *this_frame, |
| void **this_cache) |
| { |
| struct sparc_frame_cache *cache; |
| CORE_ADDR addr; |
| |
| if (*this_cache) |
| return (struct sparc_frame_cache *) *this_cache; |
| |
| cache = sparc_frame_cache (this_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 = get_frame_pc (this_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. */ |
| sparc_record_save_insn (cache); |
| addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM); |
| cache->base = addr; |
| } |
| |
| cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (this_frame); |
| |
| return cache; |
| } |
| |
| static void |
| sparc32obsd_sigtramp_frame_this_id (struct frame_info *this_frame, |
| void **this_cache, |
| struct frame_id *this_id) |
| { |
| struct sparc_frame_cache *cache = |
| sparc32obsd_sigtramp_frame_cache (this_frame, this_cache); |
| |
| (*this_id) = frame_id_build (cache->base, cache->pc); |
| } |
| |
| static struct value * |
| sparc32obsd_sigtramp_frame_prev_register (struct frame_info *this_frame, |
| void **this_cache, int regnum) |
| { |
| struct sparc_frame_cache *cache = |
| sparc32obsd_sigtramp_frame_cache (this_frame, this_cache); |
| |
| return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum); |
| } |
| |
| static int |
| sparc32obsd_sigtramp_frame_sniffer (const struct frame_unwind *self, |
| struct frame_info *this_frame, |
| void **this_cache) |
| { |
| CORE_ADDR pc = get_frame_pc (this_frame); |
| const char *name; |
| |
| find_pc_partial_function (pc, &name, NULL, NULL); |
| if (sparc32obsd_pc_in_sigtramp (pc, name)) |
| return 1; |
| |
| return 0; |
| } |
| static const struct frame_unwind sparc32obsd_sigtramp_frame_unwind = |
| { |
| "sparc32 openbsd sigtramp", |
| SIGTRAMP_FRAME, |
| default_frame_unwind_stop_reason, |
| sparc32obsd_sigtramp_frame_this_id, |
| sparc32obsd_sigtramp_frame_prev_register, |
| NULL, |
| sparc32obsd_sigtramp_frame_sniffer |
| }; |
| |
| |
| |
| /* Offset wthin the thread structure where we can find %fp and %i7. */ |
| #define SPARC32OBSD_UTHREAD_FP_OFFSET 128 |
| #define SPARC32OBSD_UTHREAD_PC_OFFSET 132 |
| |
| static void |
| sparc32obsd_supply_uthread (struct regcache *regcache, |
| int regnum, CORE_ADDR addr) |
| { |
| struct gdbarch *gdbarch = regcache->arch (); |
| enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| CORE_ADDR fp, fp_addr = addr + SPARC32OBSD_UTHREAD_FP_OFFSET; |
| gdb_byte buf[4]; |
| |
| /* This function calls functions that depend on the global current thread. */ |
| gdb_assert (regcache->ptid () == inferior_ptid); |
| |
| gdb_assert (regnum >= -1); |
| |
| fp = read_memory_unsigned_integer (fp_addr, 4, byte_order); |
| if (regnum == SPARC_SP_REGNUM || regnum == -1) |
| { |
| store_unsigned_integer (buf, 4, byte_order, fp); |
| regcache->raw_supply (SPARC_SP_REGNUM, buf); |
| |
| if (regnum == SPARC_SP_REGNUM) |
| return; |
| } |
| |
| if (regnum == SPARC32_PC_REGNUM || regnum == SPARC32_NPC_REGNUM |
| || regnum == -1) |
| { |
| CORE_ADDR i7, i7_addr = addr + SPARC32OBSD_UTHREAD_PC_OFFSET; |
| |
| i7 = read_memory_unsigned_integer (i7_addr, 4, byte_order); |
| if (regnum == SPARC32_PC_REGNUM || regnum == -1) |
| { |
| store_unsigned_integer (buf, 4, byte_order, i7 + 8); |
| regcache->raw_supply (SPARC32_PC_REGNUM, buf); |
| } |
| if (regnum == SPARC32_NPC_REGNUM || regnum == -1) |
| { |
| store_unsigned_integer (buf, 4, byte_order, i7 + 12); |
| regcache->raw_supply (SPARC32_NPC_REGNUM, buf); |
| } |
| |
| if (regnum == SPARC32_PC_REGNUM || regnum == SPARC32_NPC_REGNUM) |
| return; |
| } |
| |
| sparc_supply_rwindow (regcache, fp, regnum); |
| } |
| |
| static void |
| sparc32obsd_collect_uthread(const struct regcache *regcache, |
| int regnum, CORE_ADDR addr) |
| { |
| struct gdbarch *gdbarch = regcache->arch (); |
| enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| CORE_ADDR sp; |
| gdb_byte buf[4]; |
| |
| /* This function calls functions that depend on the global current thread. */ |
| gdb_assert (regcache->ptid () == inferior_ptid); |
| |
| gdb_assert (regnum >= -1); |
| |
| if (regnum == SPARC_SP_REGNUM || regnum == -1) |
| { |
| CORE_ADDR fp_addr = addr + SPARC32OBSD_UTHREAD_FP_OFFSET; |
| |
| regcache->raw_collect (SPARC_SP_REGNUM, buf); |
| write_memory (fp_addr,buf, 4); |
| } |
| |
| if (regnum == SPARC32_PC_REGNUM || regnum == -1) |
| { |
| CORE_ADDR i7, i7_addr = addr + SPARC32OBSD_UTHREAD_PC_OFFSET; |
| |
| regcache->raw_collect (SPARC32_PC_REGNUM, buf); |
| i7 = extract_unsigned_integer (buf, 4, byte_order) - 8; |
| write_memory_unsigned_integer (i7_addr, 4, byte_order, i7); |
| |
| if (regnum == SPARC32_PC_REGNUM) |
| return; |
| } |
| |
| regcache->raw_collect (SPARC_SP_REGNUM, buf); |
| sp = extract_unsigned_integer (buf, 4, byte_order); |
| sparc_collect_rwindow (regcache, sp, regnum); |
| } |
| |
| |
| static void |
| sparc32obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| { |
| /* OpenBSD/sparc is very similar to NetBSD/sparc ELF. */ |
| sparc32nbsd_init_abi (info, gdbarch); |
| |
| set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver); |
| |
| frame_unwind_append_unwinder (gdbarch, &sparc32obsd_sigtramp_frame_unwind); |
| |
| /* OpenBSD provides a user-level threads implementation. */ |
| bsd_uthread_set_supply_uthread (gdbarch, sparc32obsd_supply_uthread); |
| bsd_uthread_set_collect_uthread (gdbarch, sparc32obsd_collect_uthread); |
| } |
| |
| void _initialize_sparc32obsd_tdep (); |
| void |
| _initialize_sparc32obsd_tdep () |
| { |
| gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_OPENBSD, |
| sparc32obsd_init_abi); |
| } |