/* Target-dependent code for OpenBSD/sparc64. Copyright (C) 2004-2016 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 "regset.h" #include "symtab.h" #include "objfiles.h" #include "trad-frame.h" #include "obsd-tdep.h" #include "sparc64-tdep.h" #include "solib-svr4.h" #include "bsd-uthread.h" /* Older OpenBSD versions used the traditional NetBSD core file format, even for ports that use ELF. These core files don't use multiple register sets. Instead, the general-purpose and floating-point registers are lumped together in a single section. Unlike on NetBSD, OpenBSD uses a different layout for its general-purpose registers than the layout used for ptrace(2). Newer OpenBSD versions use ELF core files. Here the register sets match the ptrace(2) layout. */ /* From <machine/reg.h>. */ const struct sparc_gregmap sparc64obsd_gregmap = { 0 * 8, /* "tstate" */ 1 * 8, /* %pc */ 2 * 8, /* %npc */ 3 * 8, /* %y */ -1, /* %fprs */ -1, 5 * 8, /* %g1 */ 20 * 8, /* %l0 */ 4 /* sizeof (%y) */ }; const struct sparc_gregmap sparc64obsd_core_gregmap = { 0 * 8, /* "tstate" */ 1 * 8, /* %pc */ 2 * 8, /* %npc */ 3 * 8, /* %y */ -1, /* %fprs */ -1, 7 * 8, /* %g1 */ 22 * 8, /* %l0 */ 4 /* sizeof (%y) */ }; static void sparc64obsd_supply_gregset (const struct regset *regset, struct regcache *regcache, int regnum, const void *gregs, size_t len) { const void *fpregs = (char *)gregs + 288; if (len < 832) { sparc64_supply_gregset (&sparc64obsd_gregmap, regcache, regnum, gregs); return; } sparc64_supply_gregset (&sparc64obsd_core_gregmap, regcache, regnum, gregs); sparc64_supply_fpregset (&sparc64_bsd_fpregmap, regcache, regnum, fpregs); } static void sparc64obsd_supply_fpregset (const struct regset *regset, struct regcache *regcache, int regnum, const void *fpregs, size_t len) { sparc64_supply_fpregset (&sparc64_bsd_fpregmap, regcache, regnum, fpregs); } /* 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 sparc64obsd_page_size = 8192; /* Offset for sigreturn(2). */ static const int sparc64obsd_sigreturn_offset[] = { 0xf0, /* OpenBSD 3.8 */ 0xec, /* OpenBSD 3.6 */ 0xe8, /* OpenBSD 3.2 */ -1 }; static int sparc64obsd_pc_in_sigtramp (CORE_ADDR pc, const char *name) { CORE_ADDR start_pc = (pc & ~(sparc64obsd_page_size - 1)); unsigned long insn; const int *offset; if (name) return 0; for (offset = sparc64obsd_sigreturn_offset; *offset != -1; offset++) { /* Check for "restore %g0, SYS_sigreturn, %g1". */ insn = sparc_fetch_instruction (start_pc + *offset); if (insn != 0x83e82067) continue; /* Check for "t ST_SYSCALL". */ insn = sparc_fetch_instruction (start_pc + *offset + 8); if (insn != 0x91d02000) continue; return 1; } return 0; } static struct sparc_frame_cache * sparc64obsd_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 &= ~(sparc64obsd_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); if (addr & 1) addr += BIAS; cache->base = addr; } /* We find the appropriate instance of `struct sigcontext' at a fixed offset in the signal frame. */ addr = cache->base + 128 + 16; cache->saved_regs = sparc64nbsd_sigcontext_saved_regs (addr, this_frame); return cache; } static void sparc64obsd_frame_this_id (struct frame_info *this_frame, void **this_cache, struct frame_id *this_id) { struct sparc_frame_cache *cache = sparc64obsd_frame_cache (this_frame, this_cache); (*this_id) = frame_id_build (cache->base, cache->pc); } static struct value * sparc64obsd_frame_prev_register (struct frame_info *this_frame, void **this_cache, int regnum) { struct sparc_frame_cache *cache = sparc64obsd_frame_cache (this_frame, this_cache); return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum); } static int sparc64obsd_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 (sparc64obsd_pc_in_sigtramp (pc, name)) return 1; return 0; } static const struct frame_unwind sparc64obsd_frame_unwind = { SIGTRAMP_FRAME, default_frame_unwind_stop_reason, sparc64obsd_frame_this_id, sparc64obsd_frame_prev_register, NULL, sparc64obsd_sigtramp_frame_sniffer }; /* Kernel debugging support. */ static struct sparc_frame_cache * sparc64obsd_trapframe_cache (struct frame_info *this_frame, void **this_cache) { struct sparc_frame_cache *cache; CORE_ADDR sp, trapframe_addr; int regnum; if (*this_cache) return (struct sparc_frame_cache *) *this_cache; cache = sparc_frame_cache (this_frame, this_cache); gdb_assert (cache == *this_cache); sp = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM); trapframe_addr = sp + BIAS + 176; cache->saved_regs = trad_frame_alloc_saved_regs (this_frame); cache->saved_regs[SPARC64_STATE_REGNUM].addr = trapframe_addr; cache->saved_regs[SPARC64_PC_REGNUM].addr = trapframe_addr + 8; cache->saved_regs[SPARC64_NPC_REGNUM].addr = trapframe_addr + 16; for (regnum = SPARC_G0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++) cache->saved_regs[regnum].addr = trapframe_addr + 48 + (regnum - SPARC_G0_REGNUM) * 8; return cache; } static void sparc64obsd_trapframe_this_id (struct frame_info *this_frame, void **this_cache, struct frame_id *this_id) { struct sparc_frame_cache *cache = sparc64obsd_trapframe_cache (this_frame, this_cache); (*this_id) = frame_id_build (cache->base, cache->pc); } static struct value * sparc64obsd_trapframe_prev_register (struct frame_info *this_frame, void **this_cache, int regnum) { struct sparc_frame_cache *cache = sparc64obsd_trapframe_cache (this_frame, this_cache); return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum); } static int sparc64obsd_trapframe_sniffer (const struct frame_unwind *self, struct frame_info *this_frame, void **this_cache) { CORE_ADDR pc; ULONGEST pstate; const char *name; /* Check whether we are in privileged mode, and bail out if we're not. */ pstate = get_frame_register_unsigned (this_frame, SPARC64_PSTATE_REGNUM); if ((pstate & SPARC64_PSTATE_PRIV) == 0) return 0; pc = get_frame_address_in_block (this_frame); find_pc_partial_function (pc, &name, NULL, NULL); if (name && strcmp (name, "Lslowtrap_reenter") == 0) return 1; return 0; } static const struct frame_unwind sparc64obsd_trapframe_unwind = { NORMAL_FRAME, default_frame_unwind_stop_reason, sparc64obsd_trapframe_this_id, sparc64obsd_trapframe_prev_register, NULL, sparc64obsd_trapframe_sniffer }; /* Threads support. */ /* Offset wthin the thread structure where we can find %fp and %i7. */ #define SPARC64OBSD_UTHREAD_FP_OFFSET 232 #define SPARC64OBSD_UTHREAD_PC_OFFSET 240 static void sparc64obsd_supply_uthread (struct regcache *regcache, int regnum, CORE_ADDR addr) { struct gdbarch *gdbarch = get_regcache_arch (regcache); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); CORE_ADDR fp, fp_addr = addr + SPARC64OBSD_UTHREAD_FP_OFFSET; gdb_byte buf[8]; gdb_assert (regnum >= -1); fp = read_memory_unsigned_integer (fp_addr, 8, byte_order); if (regnum == SPARC_SP_REGNUM || regnum == -1) { store_unsigned_integer (buf, 8, byte_order, fp); regcache_raw_supply (regcache, SPARC_SP_REGNUM, buf); if (regnum == SPARC_SP_REGNUM) return; } if (regnum == SPARC64_PC_REGNUM || regnum == SPARC64_NPC_REGNUM || regnum == -1) { CORE_ADDR i7, i7_addr = addr + SPARC64OBSD_UTHREAD_PC_OFFSET; i7 = read_memory_unsigned_integer (i7_addr, 8, byte_order); if (regnum == SPARC64_PC_REGNUM || regnum == -1) { store_unsigned_integer (buf, 8, byte_order, i7 + 8); regcache_raw_supply (regcache, SPARC64_PC_REGNUM, buf); } if (regnum == SPARC64_NPC_REGNUM || regnum == -1) { store_unsigned_integer (buf, 8, byte_order, i7 + 12); regcache_raw_supply (regcache, SPARC64_NPC_REGNUM, buf); } if (regnum == SPARC64_PC_REGNUM || regnum == SPARC64_NPC_REGNUM) return; } sparc_supply_rwindow (regcache, fp, regnum); } static void sparc64obsd_collect_uthread(const struct regcache *regcache, int regnum, CORE_ADDR addr) { struct gdbarch *gdbarch = get_regcache_arch (regcache); enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); CORE_ADDR sp; gdb_byte buf[8]; gdb_assert (regnum >= -1); if (regnum == SPARC_SP_REGNUM || regnum == -1) { CORE_ADDR fp_addr = addr + SPARC64OBSD_UTHREAD_FP_OFFSET; regcache_raw_collect (regcache, SPARC_SP_REGNUM, buf); write_memory (fp_addr,buf, 8); } if (regnum == SPARC64_PC_REGNUM || regnum == -1) { CORE_ADDR i7, i7_addr = addr + SPARC64OBSD_UTHREAD_PC_OFFSET; regcache_raw_collect (regcache, SPARC64_PC_REGNUM, buf); i7 = extract_unsigned_integer (buf, 8, byte_order) - 8; write_memory_unsigned_integer (i7_addr, 8, byte_order, i7); if (regnum == SPARC64_PC_REGNUM) return; } regcache_raw_collect (regcache, SPARC_SP_REGNUM, buf); sp = extract_unsigned_integer (buf, 8, byte_order); sparc_collect_rwindow (regcache, sp, regnum); } static const struct regset sparc64obsd_gregset = { NULL, sparc64obsd_supply_gregset, NULL }; static const struct regset sparc64obsd_fpregset = { NULL, sparc64obsd_supply_fpregset, NULL }; static void sparc64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); tdep->gregset = &sparc64obsd_gregset; tdep->sizeof_gregset = 288; tdep->fpregset = &sparc64obsd_fpregset; tdep->sizeof_fpregset = 272; /* Make sure we can single-step "new" syscalls. */ tdep->step_trap = sparcnbsd_step_trap; frame_unwind_append_unwinder (gdbarch, &sparc64obsd_frame_unwind); frame_unwind_append_unwinder (gdbarch, &sparc64obsd_trapframe_unwind); sparc64_init_abi (info, gdbarch); obsd_init_abi (info, gdbarch); /* OpenBSD/sparc64 has SVR4-style shared libraries. */ set_solib_svr4_fetch_link_map_offsets (gdbarch, svr4_lp64_fetch_link_map_offsets); set_gdbarch_skip_solib_resolver (gdbarch, obsd_skip_solib_resolver); /* OpenBSD provides a user-level threads implementation. */ bsd_uthread_set_supply_uthread (gdbarch, sparc64obsd_supply_uthread); bsd_uthread_set_collect_uthread (gdbarch, sparc64obsd_collect_uthread); } /* Provide a prototype to silence -Wmissing-prototypes. */ void _initialize_sparc64obsd_tdep (void); void _initialize_sparc64obsd_tdep (void) { gdbarch_register_osabi (bfd_arch_sparc, bfd_mach_sparc_v9, GDB_OSABI_OPENBSD_ELF, sparc64obsd_init_abi); }