/* Darwin support for GDB, the GNU debugger. Copyright (C) 1997-2018 Free Software Foundation, Inc. Contributed by Apple Computer, 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 . */ #include "defs.h" #include "frame.h" #include "inferior.h" #include "target.h" #include "symfile.h" #include "symtab.h" #include "objfiles.h" #include "gdbcmd.h" #include "regcache.h" #include "i386-tdep.h" #include "i387-tdep.h" #include "gdbarch.h" #include "arch-utils.h" #include "gdbcore.h" #include "x86-nat.h" #include "darwin-nat.h" #include "i386-darwin-tdep.h" #ifdef BFD64 #include "amd64-nat.h" #include "amd64-tdep.h" #include "amd64-darwin-tdep.h" #endif /* Read register values from the inferior process. If REGNO is -1, do this for all registers. Otherwise, REGNO specifies which register (so we can save time). */ static void i386_darwin_fetch_inferior_registers (struct target_ops *ops, struct regcache *regcache, int regno) { thread_t current_thread = ptid_get_tid (regcache_get_ptid (regcache)); int fetched = 0; struct gdbarch *gdbarch = regcache->arch (); #ifdef BFD64 if (gdbarch_ptr_bit (gdbarch) == 64) { if (regno == -1 || amd64_native_gregset_supplies_p (gdbarch, regno)) { x86_thread_state_t gp_regs; unsigned int gp_count = x86_THREAD_STATE_COUNT; kern_return_t ret; ret = thread_get_state (current_thread, x86_THREAD_STATE, (thread_state_t) & gp_regs, &gp_count); if (ret != KERN_SUCCESS) { printf_unfiltered (_("Error calling thread_get_state for " "GP registers for thread 0x%lx\n"), (unsigned long) current_thread); MACH_CHECK_ERROR (ret); } /* Some kernels don't sanitize the values. */ gp_regs.uts.ts64.__fs &= 0xffff; gp_regs.uts.ts64.__gs &= 0xffff; amd64_supply_native_gregset (regcache, &gp_regs.uts, -1); fetched++; } if (regno == -1 || !amd64_native_gregset_supplies_p (gdbarch, regno)) { x86_float_state_t fp_regs; unsigned int fp_count = x86_FLOAT_STATE_COUNT; kern_return_t ret; ret = thread_get_state (current_thread, x86_FLOAT_STATE, (thread_state_t) & fp_regs, &fp_count); if (ret != KERN_SUCCESS) { printf_unfiltered (_("Error calling thread_get_state for " "float registers for thread 0x%lx\n"), (unsigned long) current_thread); MACH_CHECK_ERROR (ret); } amd64_supply_fxsave (regcache, -1, &fp_regs.ufs.fs64.__fpu_fcw); fetched++; } } else #endif { if (regno == -1 || regno < I386_NUM_GREGS) { x86_thread_state32_t gp_regs; unsigned int gp_count = x86_THREAD_STATE32_COUNT; kern_return_t ret; int i; ret = thread_get_state (current_thread, x86_THREAD_STATE32, (thread_state_t) &gp_regs, &gp_count); if (ret != KERN_SUCCESS) { printf_unfiltered (_("Error calling thread_get_state for " "GP registers for thread 0x%lx\n"), (unsigned long) current_thread); MACH_CHECK_ERROR (ret); } for (i = 0; i < I386_NUM_GREGS; i++) regcache_raw_supply (regcache, i, (char *)&gp_regs + i386_darwin_thread_state_reg_offset[i]); fetched++; } if (regno == -1 || (regno >= I386_ST0_REGNUM && regno < I386_SSE_NUM_REGS)) { x86_float_state32_t fp_regs; unsigned int fp_count = x86_FLOAT_STATE32_COUNT; kern_return_t ret; ret = thread_get_state (current_thread, x86_FLOAT_STATE32, (thread_state_t) &fp_regs, &fp_count); if (ret != KERN_SUCCESS) { printf_unfiltered (_("Error calling thread_get_state for " "float registers for thread 0x%lx\n"), (unsigned long) current_thread); MACH_CHECK_ERROR (ret); } i387_supply_fxsave (regcache, -1, &fp_regs.__fpu_fcw); fetched++; } } if (! fetched) { warning (_("unknown register %d"), regno); regcache_raw_supply (regcache, regno, NULL); } } /* Store our register values back into the inferior. If REGNO is -1, do this for all registers. Otherwise, REGNO specifies which register (so we can save time). */ static void i386_darwin_store_inferior_registers (struct target_ops *ops, struct regcache *regcache, int regno) { thread_t current_thread = ptid_get_tid (regcache_get_ptid (regcache)); struct gdbarch *gdbarch = regcache->arch (); #ifdef BFD64 if (gdbarch_ptr_bit (gdbarch) == 64) { if (regno == -1 || amd64_native_gregset_supplies_p (gdbarch, regno)) { x86_thread_state_t gp_regs; kern_return_t ret; unsigned int gp_count = x86_THREAD_STATE_COUNT; ret = thread_get_state (current_thread, x86_THREAD_STATE, (thread_state_t) &gp_regs, &gp_count); MACH_CHECK_ERROR (ret); gdb_assert (gp_regs.tsh.flavor == x86_THREAD_STATE64); gdb_assert (gp_regs.tsh.count == x86_THREAD_STATE64_COUNT); amd64_collect_native_gregset (regcache, &gp_regs.uts, regno); /* Some kernels don't sanitize the values. */ gp_regs.uts.ts64.__fs &= 0xffff; gp_regs.uts.ts64.__gs &= 0xffff; ret = thread_set_state (current_thread, x86_THREAD_STATE, (thread_state_t) &gp_regs, x86_THREAD_STATE_COUNT); MACH_CHECK_ERROR (ret); } if (regno == -1 || !amd64_native_gregset_supplies_p (gdbarch, regno)) { x86_float_state_t fp_regs; kern_return_t ret; unsigned int fp_count = x86_FLOAT_STATE_COUNT; ret = thread_get_state (current_thread, x86_FLOAT_STATE, (thread_state_t) & fp_regs, &fp_count); MACH_CHECK_ERROR (ret); gdb_assert (fp_regs.fsh.flavor == x86_FLOAT_STATE64); gdb_assert (fp_regs.fsh.count == x86_FLOAT_STATE64_COUNT); amd64_collect_fxsave (regcache, regno, &fp_regs.ufs.fs64.__fpu_fcw); ret = thread_set_state (current_thread, x86_FLOAT_STATE, (thread_state_t) & fp_regs, x86_FLOAT_STATE_COUNT); MACH_CHECK_ERROR (ret); } } else #endif { if (regno == -1 || regno < I386_NUM_GREGS) { x86_thread_state32_t gp_regs; kern_return_t ret; unsigned int gp_count = x86_THREAD_STATE32_COUNT; int i; ret = thread_get_state (current_thread, x86_THREAD_STATE32, (thread_state_t) &gp_regs, &gp_count); MACH_CHECK_ERROR (ret); for (i = 0; i < I386_NUM_GREGS; i++) if (regno == -1 || regno == i) regcache_raw_collect (regcache, i, (char *)&gp_regs + i386_darwin_thread_state_reg_offset[i]); ret = thread_set_state (current_thread, x86_THREAD_STATE32, (thread_state_t) &gp_regs, x86_THREAD_STATE32_COUNT); MACH_CHECK_ERROR (ret); } if (regno == -1 || (regno >= I386_ST0_REGNUM && regno < I386_SSE_NUM_REGS)) { x86_float_state32_t fp_regs; unsigned int fp_count = x86_FLOAT_STATE32_COUNT; kern_return_t ret; ret = thread_get_state (current_thread, x86_FLOAT_STATE32, (thread_state_t) & fp_regs, &fp_count); MACH_CHECK_ERROR (ret); i387_collect_fxsave (regcache, regno, &fp_regs.__fpu_fcw); ret = thread_set_state (current_thread, x86_FLOAT_STATE32, (thread_state_t) &fp_regs, x86_FLOAT_STATE32_COUNT); MACH_CHECK_ERROR (ret); } } } /* Support for debug registers, boosted mostly from i386-linux-nat.c. */ static void i386_darwin_dr_set (int regnum, CORE_ADDR value) { int current_pid; thread_t current_thread; x86_debug_state_t dr_regs; kern_return_t ret; unsigned int dr_count; gdb_assert (regnum >= 0 && regnum <= DR_CONTROL); current_thread = ptid_get_tid (inferior_ptid); dr_regs.dsh.flavor = x86_DEBUG_STATE; dr_regs.dsh.count = x86_DEBUG_STATE_COUNT; dr_count = x86_DEBUG_STATE_COUNT; ret = thread_get_state (current_thread, x86_DEBUG_STATE, (thread_state_t) &dr_regs, &dr_count); MACH_CHECK_ERROR (ret); switch (dr_regs.dsh.flavor) { case x86_DEBUG_STATE32: switch (regnum) { case 0: dr_regs.uds.ds32.__dr0 = value; break; case 1: dr_regs.uds.ds32.__dr1 = value; break; case 2: dr_regs.uds.ds32.__dr2 = value; break; case 3: dr_regs.uds.ds32.__dr3 = value; break; case 4: dr_regs.uds.ds32.__dr4 = value; break; case 5: dr_regs.uds.ds32.__dr5 = value; break; case 6: dr_regs.uds.ds32.__dr6 = value; break; case 7: dr_regs.uds.ds32.__dr7 = value; break; } break; #ifdef BFD64 case x86_DEBUG_STATE64: switch (regnum) { case 0: dr_regs.uds.ds64.__dr0 = value; break; case 1: dr_regs.uds.ds64.__dr1 = value; break; case 2: dr_regs.uds.ds64.__dr2 = value; break; case 3: dr_regs.uds.ds64.__dr3 = value; break; case 4: dr_regs.uds.ds64.__dr4 = value; break; case 5: dr_regs.uds.ds64.__dr5 = value; break; case 6: dr_regs.uds.ds64.__dr6 = value; break; case 7: dr_regs.uds.ds64.__dr7 = value; break; } break; #endif } ret = thread_set_state (current_thread, dr_regs.dsh.flavor, (thread_state_t) &dr_regs.uds, dr_count); MACH_CHECK_ERROR (ret); } static CORE_ADDR i386_darwin_dr_get (int regnum) { thread_t current_thread; x86_debug_state_t dr_regs; kern_return_t ret; unsigned int dr_count; gdb_assert (regnum >= 0 && regnum <= DR_CONTROL); current_thread = ptid_get_tid (inferior_ptid); dr_regs.dsh.flavor = x86_DEBUG_STATE; dr_regs.dsh.count = x86_DEBUG_STATE_COUNT; dr_count = x86_DEBUG_STATE_COUNT; ret = thread_get_state (current_thread, x86_DEBUG_STATE, (thread_state_t) &dr_regs, &dr_count); MACH_CHECK_ERROR (ret); switch (dr_regs.dsh.flavor) { case x86_DEBUG_STATE32: switch (regnum) { case 0: return dr_regs.uds.ds32.__dr0; case 1: return dr_regs.uds.ds32.__dr1; case 2: return dr_regs.uds.ds32.__dr2; case 3: return dr_regs.uds.ds32.__dr3; case 4: return dr_regs.uds.ds32.__dr4; case 5: return dr_regs.uds.ds32.__dr5; case 6: return dr_regs.uds.ds32.__dr6; case 7: return dr_regs.uds.ds32.__dr7; default: return -1; } break; #ifdef BFD64 case x86_DEBUG_STATE64: switch (regnum) { case 0: return dr_regs.uds.ds64.__dr0; case 1: return dr_regs.uds.ds64.__dr1; case 2: return dr_regs.uds.ds64.__dr2; case 3: return dr_regs.uds.ds64.__dr3; case 4: return dr_regs.uds.ds64.__dr4; case 5: return dr_regs.uds.ds64.__dr5; case 6: return dr_regs.uds.ds64.__dr6; case 7: return dr_regs.uds.ds64.__dr7; default: return -1; } break; #endif default: return -1; } } static void i386_darwin_dr_set_control (unsigned long control) { i386_darwin_dr_set (DR_CONTROL, control); } static void i386_darwin_dr_set_addr (int regnum, CORE_ADDR addr) { gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR); i386_darwin_dr_set (DR_FIRSTADDR + regnum, addr); } static CORE_ADDR i386_darwin_dr_get_addr (int regnum) { return i386_darwin_dr_get (regnum); } static unsigned long i386_darwin_dr_get_status (void) { return i386_darwin_dr_get (DR_STATUS); } static unsigned long i386_darwin_dr_get_control (void) { return i386_darwin_dr_get (DR_CONTROL); } void darwin_check_osabi (darwin_inferior *inf, thread_t thread) { if (gdbarch_osabi (target_gdbarch ()) == GDB_OSABI_UNKNOWN) { /* Attaching to a process. Let's figure out what kind it is. */ x86_thread_state_t gp_regs; struct gdbarch_info info; unsigned int gp_count = x86_THREAD_STATE_COUNT; kern_return_t ret; ret = thread_get_state (thread, x86_THREAD_STATE, (thread_state_t) &gp_regs, &gp_count); if (ret != KERN_SUCCESS) { MACH_CHECK_ERROR (ret); return; } gdbarch_info_init (&info); gdbarch_info_fill (&info); info.byte_order = gdbarch_byte_order (target_gdbarch ()); info.osabi = GDB_OSABI_DARWIN; if (gp_regs.tsh.flavor == x86_THREAD_STATE64) info.bfd_arch_info = bfd_lookup_arch (bfd_arch_i386, bfd_mach_x86_64); else info.bfd_arch_info = bfd_lookup_arch (bfd_arch_i386, bfd_mach_i386_i386); gdbarch_update_p (info); } } #define X86_EFLAGS_T 0x100UL /* Returning from a signal trampoline is done by calling a special system call (sigreturn). This system call restores the registers that were saved when the signal was raised, including %eflags/%rflags. That means that single-stepping won't work. Instead, we'll have to modify the signal context that's about to be restored, and set the trace flag there. */ static int i386_darwin_sstep_at_sigreturn (x86_thread_state_t *regs) { enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); static const gdb_byte darwin_syscall[] = { 0xcd, 0x80 }; /* int 0x80 */ gdb_byte buf[sizeof (darwin_syscall)]; /* Check if PC is at a sigreturn system call. */ if (target_read_memory (regs->uts.ts32.__eip, buf, sizeof (buf)) == 0 && memcmp (buf, darwin_syscall, sizeof (darwin_syscall)) == 0 && regs->uts.ts32.__eax == 0xb8 /* SYS_sigreturn */) { ULONGEST uctx_addr; ULONGEST mctx_addr; ULONGEST flags_addr; unsigned int eflags; uctx_addr = read_memory_unsigned_integer (regs->uts.ts32.__esp + 4, 4, byte_order); mctx_addr = read_memory_unsigned_integer (uctx_addr + 28, 4, byte_order); flags_addr = mctx_addr + 12 + 9 * 4; read_memory (flags_addr, (gdb_byte *) &eflags, 4); eflags |= X86_EFLAGS_T; write_memory (flags_addr, (gdb_byte *) &eflags, 4); return 1; } return 0; } #ifdef BFD64 static int amd64_darwin_sstep_at_sigreturn (x86_thread_state_t *regs) { enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ()); static const gdb_byte darwin_syscall[] = { 0x0f, 0x05 }; /* syscall */ gdb_byte buf[sizeof (darwin_syscall)]; /* Check if PC is at a sigreturn system call. */ if (target_read_memory (regs->uts.ts64.__rip, buf, sizeof (buf)) == 0 && memcmp (buf, darwin_syscall, sizeof (darwin_syscall)) == 0 && (regs->uts.ts64.__rax & 0xffffffff) == 0x20000b8 /* SYS_sigreturn */) { ULONGEST mctx_addr; ULONGEST flags_addr; unsigned int rflags; mctx_addr = read_memory_unsigned_integer (regs->uts.ts64.__rdi + 48, 8, byte_order); flags_addr = mctx_addr + 16 + 17 * 8; /* AMD64 is little endian. */ read_memory (flags_addr, (gdb_byte *) &rflags, 4); rflags |= X86_EFLAGS_T; write_memory (flags_addr, (gdb_byte *) &rflags, 4); return 1; } return 0; } #endif void darwin_set_sstep (thread_t thread, int enable) { x86_thread_state_t regs; unsigned int count = x86_THREAD_STATE_COUNT; kern_return_t kret; kret = thread_get_state (thread, x86_THREAD_STATE, (thread_state_t) ®s, &count); if (kret != KERN_SUCCESS) { printf_unfiltered (_("darwin_set_sstep: error %x, thread=%x\n"), kret, thread); return; } switch (regs.tsh.flavor) { case x86_THREAD_STATE32: { __uint32_t bit = enable ? X86_EFLAGS_T : 0; if (enable && i386_darwin_sstep_at_sigreturn (®s)) return; if ((regs.uts.ts32.__eflags & X86_EFLAGS_T) == bit) return; regs.uts.ts32.__eflags = (regs.uts.ts32.__eflags & ~X86_EFLAGS_T) | bit; kret = thread_set_state (thread, x86_THREAD_STATE, (thread_state_t) ®s, count); MACH_CHECK_ERROR (kret); } break; #ifdef BFD64 case x86_THREAD_STATE64: { __uint64_t bit = enable ? X86_EFLAGS_T : 0; if (enable && amd64_darwin_sstep_at_sigreturn (®s)) return; if ((regs.uts.ts64.__rflags & X86_EFLAGS_T) == bit) return; regs.uts.ts64.__rflags = (regs.uts.ts64.__rflags & ~X86_EFLAGS_T) | bit; kret = thread_set_state (thread, x86_THREAD_STATE, (thread_state_t) ®s, count); MACH_CHECK_ERROR (kret); } break; #endif default: error (_("darwin_set_sstep: unknown flavour: %d"), regs.tsh.flavor); } } void darwin_complete_target (struct target_ops *target) { #ifdef BFD64 amd64_native_gregset64_reg_offset = amd64_darwin_thread_state_reg_offset; amd64_native_gregset64_num_regs = amd64_darwin_thread_state_num_regs; amd64_native_gregset32_reg_offset = i386_darwin_thread_state_reg_offset; amd64_native_gregset32_num_regs = i386_darwin_thread_state_num_regs; #endif x86_use_watchpoints (target); x86_dr_low.set_control = i386_darwin_dr_set_control; x86_dr_low.set_addr = i386_darwin_dr_set_addr; x86_dr_low.get_addr = i386_darwin_dr_get_addr; x86_dr_low.get_status = i386_darwin_dr_get_status; x86_dr_low.get_control = i386_darwin_dr_get_control; /* Let's assume that the kernel is 64 bits iff the executable is. */ #ifdef __x86_64__ x86_set_debug_register_length (8); #else x86_set_debug_register_length (4); #endif target->to_fetch_registers = i386_darwin_fetch_inferior_registers; target->to_store_registers = i386_darwin_store_inferior_registers; }