/* Native-dependent code for GNU/Linux x86-64. Copyright (C) 2001-2012 Free Software Foundation, Inc. Contributed by Jiri Smid, SuSE Labs. 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 "inferior.h" #include "gdbcore.h" #include "regcache.h" #include "regset.h" #include "linux-nat.h" #include "amd64-linux-tdep.h" #include "gdb_assert.h" #include "gdb_string.h" #include "elf/common.h" #include #include #include #include #include #include /* FIXME ezannoni-2003-07-09: we need to be included after because the latter redefines FS and GS for no apparent reason, and those definitions don't match the ones that libpthread_db uses, which come from . */ /* ezannoni-2003-07-09: I think this is fixed. The extraneous defs have been removed from ptrace.h in the kernel. However, better safe than sorry. */ #include #include #include "gdb_proc_service.h" /* Prototypes for supply_gregset etc. */ #include "gregset.h" #include "amd64-tdep.h" #include "i386-linux-tdep.h" #include "amd64-nat.h" #include "i386-nat.h" #include "i386-xstate.h" #ifndef PTRACE_GETREGSET #define PTRACE_GETREGSET 0x4204 #endif #ifndef PTRACE_SETREGSET #define PTRACE_SETREGSET 0x4205 #endif /* Per-thread arch-specific data we want to keep. */ struct arch_lwp_info { /* Non-zero if our copy differs from what's recorded in the thread. */ int debug_registers_changed; }; /* Does the current host support PTRACE_GETREGSET? */ static int have_ptrace_getregset = -1; /* Mapping between the general-purpose registers in GNU/Linux x86-64 `struct user' format and GDB's register cache layout for GNU/Linux i386. Note that most GNU/Linux x86-64 registers are 64-bit, while the GNU/Linux i386 registers are all 32-bit, but since we're little-endian we get away with that. */ /* From on GNU/Linux i386. */ static int amd64_linux_gregset32_reg_offset[] = { RAX * 8, RCX * 8, /* %eax, %ecx */ RDX * 8, RBX * 8, /* %edx, %ebx */ RSP * 8, RBP * 8, /* %esp, %ebp */ RSI * 8, RDI * 8, /* %esi, %edi */ RIP * 8, EFLAGS * 8, /* %eip, %eflags */ CS * 8, SS * 8, /* %cs, %ss */ DS * 8, ES * 8, /* %ds, %es */ FS * 8, GS * 8, /* %fs, %gs */ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, ORIG_RAX * 8 /* "orig_eax" */ }; /* Transfering the general-purpose registers between GDB, inferiors and core files. */ /* Fill GDB's register cache with the general-purpose register values in *GREGSETP. */ void supply_gregset (struct regcache *regcache, const elf_gregset_t *gregsetp) { amd64_supply_native_gregset (regcache, gregsetp, -1); } /* Fill register REGNUM (if it is a general-purpose register) in *GREGSETP with the value in GDB's register cache. If REGNUM is -1, do this for all registers. */ void fill_gregset (const struct regcache *regcache, elf_gregset_t *gregsetp, int regnum) { amd64_collect_native_gregset (regcache, gregsetp, regnum); } /* Transfering floating-point registers between GDB, inferiors and cores. */ /* Fill GDB's register cache with the floating-point and SSE register values in *FPREGSETP. */ void supply_fpregset (struct regcache *regcache, const elf_fpregset_t *fpregsetp) { amd64_supply_fxsave (regcache, -1, fpregsetp); } /* Fill register REGNUM (if it is a floating-point or SSE register) in *FPREGSETP with the value in GDB's register cache. If REGNUM is -1, do this for all registers. */ void fill_fpregset (const struct regcache *regcache, elf_fpregset_t *fpregsetp, int regnum) { amd64_collect_fxsave (regcache, regnum, fpregsetp); } /* Transferring arbitrary registers between GDB and inferior. */ /* Fetch register REGNUM from the child process. If REGNUM is -1, do this for all registers (including the floating point and SSE registers). */ static void amd64_linux_fetch_inferior_registers (struct target_ops *ops, struct regcache *regcache, int regnum) { struct gdbarch *gdbarch = get_regcache_arch (regcache); int tid; /* GNU/Linux LWP ID's are process ID's. */ tid = TIDGET (inferior_ptid); if (tid == 0) tid = PIDGET (inferior_ptid); /* Not a threaded program. */ if (regnum == -1 || amd64_native_gregset_supplies_p (gdbarch, regnum)) { elf_gregset_t regs; if (ptrace (PTRACE_GETREGS, tid, 0, (long) ®s) < 0) perror_with_name (_("Couldn't get registers")); amd64_supply_native_gregset (regcache, ®s, -1); if (regnum != -1) return; } if (regnum == -1 || !amd64_native_gregset_supplies_p (gdbarch, regnum)) { elf_fpregset_t fpregs; if (have_ptrace_getregset) { char xstateregs[I386_XSTATE_MAX_SIZE]; struct iovec iov; iov.iov_base = xstateregs; iov.iov_len = sizeof (xstateregs); if (ptrace (PTRACE_GETREGSET, tid, (unsigned int) NT_X86_XSTATE, (long) &iov) < 0) perror_with_name (_("Couldn't get extended state status")); amd64_supply_xsave (regcache, -1, xstateregs); } else { if (ptrace (PTRACE_GETFPREGS, tid, 0, (long) &fpregs) < 0) perror_with_name (_("Couldn't get floating point status")); amd64_supply_fxsave (regcache, -1, &fpregs); } } } /* Store register REGNUM back into the child process. If REGNUM is -1, do this for all registers (including the floating-point and SSE registers). */ static void amd64_linux_store_inferior_registers (struct target_ops *ops, struct regcache *regcache, int regnum) { struct gdbarch *gdbarch = get_regcache_arch (regcache); int tid; /* GNU/Linux LWP ID's are process ID's. */ tid = TIDGET (inferior_ptid); if (tid == 0) tid = PIDGET (inferior_ptid); /* Not a threaded program. */ if (regnum == -1 || amd64_native_gregset_supplies_p (gdbarch, regnum)) { elf_gregset_t regs; if (ptrace (PTRACE_GETREGS, tid, 0, (long) ®s) < 0) perror_with_name (_("Couldn't get registers")); amd64_collect_native_gregset (regcache, ®s, regnum); if (ptrace (PTRACE_SETREGS, tid, 0, (long) ®s) < 0) perror_with_name (_("Couldn't write registers")); if (regnum != -1) return; } if (regnum == -1 || !amd64_native_gregset_supplies_p (gdbarch, regnum)) { elf_fpregset_t fpregs; if (have_ptrace_getregset) { char xstateregs[I386_XSTATE_MAX_SIZE]; struct iovec iov; iov.iov_base = xstateregs; iov.iov_len = sizeof (xstateregs); if (ptrace (PTRACE_GETREGSET, tid, (unsigned int) NT_X86_XSTATE, (long) &iov) < 0) perror_with_name (_("Couldn't get extended state status")); amd64_collect_xsave (regcache, regnum, xstateregs, 0); if (ptrace (PTRACE_SETREGSET, tid, (unsigned int) NT_X86_XSTATE, (long) &iov) < 0) perror_with_name (_("Couldn't write extended state status")); } else { if (ptrace (PTRACE_GETFPREGS, tid, 0, (long) &fpregs) < 0) perror_with_name (_("Couldn't get floating point status")); amd64_collect_fxsave (regcache, regnum, &fpregs); if (ptrace (PTRACE_SETFPREGS, tid, 0, (long) &fpregs) < 0) perror_with_name (_("Couldn't write floating point status")); } } } /* Support for debug registers. */ static unsigned long amd64_linux_dr_get (ptid_t ptid, int regnum) { int tid; unsigned long value; tid = TIDGET (ptid); if (tid == 0) tid = PIDGET (ptid); errno = 0; value = ptrace (PTRACE_PEEKUSER, tid, offsetof (struct user, u_debugreg[regnum]), 0); if (errno != 0) perror_with_name (_("Couldn't read debug register")); return value; } /* Set debug register REGNUM to VALUE in only the one LWP of PTID. */ static void amd64_linux_dr_set (ptid_t ptid, int regnum, unsigned long value) { int tid; tid = TIDGET (ptid); if (tid == 0) tid = PIDGET (ptid); errno = 0; ptrace (PTRACE_POKEUSER, tid, offsetof (struct user, u_debugreg[regnum]), value); if (errno != 0) perror_with_name (_("Couldn't write debug register")); } /* Return the inferior's debug register REGNUM. */ static CORE_ADDR amd64_linux_dr_get_addr (int regnum) { /* DR6 and DR7 are retrieved with some other way. */ gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR); return amd64_linux_dr_get (inferior_ptid, regnum); } /* Return the inferior's DR7 debug control register. */ static unsigned long amd64_linux_dr_get_control (void) { return amd64_linux_dr_get (inferior_ptid, DR_CONTROL); } /* Get DR_STATUS from only the one LWP of INFERIOR_PTID. */ static unsigned long amd64_linux_dr_get_status (void) { return amd64_linux_dr_get (inferior_ptid, DR_STATUS); } /* Callback for linux_nat_iterate_watchpoint_lwps. Update the debug registers of LWP. */ static int update_debug_registers_callback (struct lwp_info *lwp, void *arg) { if (lwp->arch_private == NULL) lwp->arch_private = XCNEW (struct arch_lwp_info); /* The actual update is done later just before resuming the lwp, we just mark that the registers need updating. */ lwp->arch_private->debug_registers_changed = 1; /* If the lwp isn't stopped, force it to momentarily pause, so we can update its debug registers. */ if (!lwp->stopped) linux_stop_lwp (lwp); /* Continue the iteration. */ return 0; } /* Set DR_CONTROL to CONTROL in all LWPs of the current inferior. */ static void amd64_linux_dr_set_control (unsigned long control) { linux_nat_iterate_watchpoint_lwps (update_debug_registers_callback, NULL); } /* Set address REGNUM (zero based) to ADDR in all LWPs of the current inferior. */ static void amd64_linux_dr_set_addr (int regnum, CORE_ADDR addr) { gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR); linux_nat_iterate_watchpoint_lwps (update_debug_registers_callback, NULL); } /* Called when resuming a thread. If the debug regs have changed, update the thread's copies. */ static void amd64_linux_prepare_to_resume (struct lwp_info *lwp) { int clear_status = 0; /* NULL means this is the main thread still going through the shell, or, no watchpoint has been set yet. In that case, there's nothing to do. */ if (lwp->arch_private == NULL) return; if (lwp->arch_private->debug_registers_changed) { struct i386_debug_reg_state *state = i386_debug_reg_state (); int i; /* On Linux kernel before 2.6.33 commit 72f674d203cd230426437cdcf7dd6f681dad8b0d if you enable a breakpoint by the DR_CONTROL bits you need to have already written the corresponding DR_FIRSTADDR...DR_LASTADDR registers. Ensure DR_CONTROL gets written as the very last register here. */ for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++) if (state->dr_ref_count[i] > 0) { amd64_linux_dr_set (lwp->ptid, i, state->dr_mirror[i]); /* If we're setting a watchpoint, any change the inferior had done itself to the debug registers needs to be discarded, otherwise, i386_stopped_data_address can get confused. */ clear_status = 1; } amd64_linux_dr_set (lwp->ptid, DR_CONTROL, state->dr_control_mirror); lwp->arch_private->debug_registers_changed = 0; } if (clear_status || lwp->stopped_by_watchpoint) amd64_linux_dr_set (lwp->ptid, DR_STATUS, 0); } static void amd64_linux_new_thread (struct lwp_info *lp) { struct arch_lwp_info *info = XCNEW (struct arch_lwp_info); info->debug_registers_changed = 1; lp->arch_private = info; } /* This function is called by libthread_db as part of its handling of a request for a thread's local storage address. */ ps_err_e ps_get_thread_area (const struct ps_prochandle *ph, lwpid_t lwpid, int idx, void **base) { if (gdbarch_ptr_bit (target_gdbarch) == 32) { /* The full structure is found in . The second integer is the LDT's base_address and that is used to locate the thread's local storage. See i386-linux-nat.c more info. */ unsigned int desc[4]; /* This code assumes that "int" is 32 bits and that GET_THREAD_AREA returns no more than 4 int values. */ gdb_assert (sizeof (int) == 4); #ifndef PTRACE_GET_THREAD_AREA #define PTRACE_GET_THREAD_AREA 25 #endif if (ptrace (PTRACE_GET_THREAD_AREA, lwpid, (void *) (long) idx, (unsigned long) &desc) < 0) return PS_ERR; /* Extend the value to 64 bits. Here it's assumed that a "long" and a "void *" are the same. */ (*base) = (void *) (long) desc[1]; return PS_OK; } else { /* This definition comes from prctl.h, but some kernels may not have it. */ #ifndef PTRACE_ARCH_PRCTL #define PTRACE_ARCH_PRCTL 30 #endif /* FIXME: ezannoni-2003-07-09 see comment above about include file order. We could be getting bogus values for these two. */ gdb_assert (FS < ELF_NGREG); gdb_assert (GS < ELF_NGREG); switch (idx) { case FS: if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_FS) == 0) return PS_OK; break; case GS: if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_GS) == 0) return PS_OK; break; default: /* Should not happen. */ return PS_BADADDR; } } return PS_ERR; /* ptrace failed. */ } static void (*super_post_startup_inferior) (ptid_t ptid); static void amd64_linux_child_post_startup_inferior (ptid_t ptid) { i386_cleanup_dregs (); super_post_startup_inferior (ptid); } /* When GDB is built as a 64-bit application on linux, the PTRACE_GETSIGINFO data is always presented in 64-bit layout. Since debugging a 32-bit inferior with a 64-bit GDB should look the same as debugging it with a 32-bit GDB, we do the 32-bit <-> 64-bit conversion in-place ourselves. */ /* These types below (compat_*) define a siginfo type that is layout compatible with the siginfo type exported by the 32-bit userspace support. */ typedef int compat_int_t; typedef unsigned int compat_uptr_t; typedef int compat_time_t; typedef int compat_timer_t; typedef int compat_clock_t; struct compat_timeval { compat_time_t tv_sec; int tv_usec; }; typedef union compat_sigval { compat_int_t sival_int; compat_uptr_t sival_ptr; } compat_sigval_t; typedef struct compat_siginfo { int si_signo; int si_errno; int si_code; union { int _pad[((128 / sizeof (int)) - 3)]; /* kill() */ struct { unsigned int _pid; unsigned int _uid; } _kill; /* POSIX.1b timers */ struct { compat_timer_t _tid; int _overrun; compat_sigval_t _sigval; } _timer; /* POSIX.1b signals */ struct { unsigned int _pid; unsigned int _uid; compat_sigval_t _sigval; } _rt; /* SIGCHLD */ struct { unsigned int _pid; unsigned int _uid; int _status; compat_clock_t _utime; compat_clock_t _stime; } _sigchld; /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */ struct { unsigned int _addr; } _sigfault; /* SIGPOLL */ struct { int _band; int _fd; } _sigpoll; } _sifields; } compat_siginfo_t; #define cpt_si_pid _sifields._kill._pid #define cpt_si_uid _sifields._kill._uid #define cpt_si_timerid _sifields._timer._tid #define cpt_si_overrun _sifields._timer._overrun #define cpt_si_status _sifields._sigchld._status #define cpt_si_utime _sifields._sigchld._utime #define cpt_si_stime _sifields._sigchld._stime #define cpt_si_ptr _sifields._rt._sigval.sival_ptr #define cpt_si_addr _sifields._sigfault._addr #define cpt_si_band _sifields._sigpoll._band #define cpt_si_fd _sifields._sigpoll._fd /* glibc at least up to 2.3.2 doesn't have si_timerid, si_overrun. In their place is si_timer1,si_timer2. */ #ifndef si_timerid #define si_timerid si_timer1 #endif #ifndef si_overrun #define si_overrun si_timer2 #endif static void compat_siginfo_from_siginfo (compat_siginfo_t *to, siginfo_t *from) { memset (to, 0, sizeof (*to)); to->si_signo = from->si_signo; to->si_errno = from->si_errno; to->si_code = from->si_code; if (to->si_code == SI_TIMER) { to->cpt_si_timerid = from->si_timerid; to->cpt_si_overrun = from->si_overrun; to->cpt_si_ptr = (intptr_t) from->si_ptr; } else if (to->si_code == SI_USER) { to->cpt_si_pid = from->si_pid; to->cpt_si_uid = from->si_uid; } else if (to->si_code < 0) { to->cpt_si_pid = from->si_pid; to->cpt_si_uid = from->si_uid; to->cpt_si_ptr = (intptr_t) from->si_ptr; } else { switch (to->si_signo) { case SIGCHLD: to->cpt_si_pid = from->si_pid; to->cpt_si_uid = from->si_uid; to->cpt_si_status = from->si_status; to->cpt_si_utime = from->si_utime; to->cpt_si_stime = from->si_stime; break; case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: to->cpt_si_addr = (intptr_t) from->si_addr; break; case SIGPOLL: to->cpt_si_band = from->si_band; to->cpt_si_fd = from->si_fd; break; default: to->cpt_si_pid = from->si_pid; to->cpt_si_uid = from->si_uid; to->cpt_si_ptr = (intptr_t) from->si_ptr; break; } } } static void siginfo_from_compat_siginfo (siginfo_t *to, compat_siginfo_t *from) { memset (to, 0, sizeof (*to)); to->si_signo = from->si_signo; to->si_errno = from->si_errno; to->si_code = from->si_code; if (to->si_code == SI_TIMER) { to->si_timerid = from->cpt_si_timerid; to->si_overrun = from->cpt_si_overrun; to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr; } else if (to->si_code == SI_USER) { to->si_pid = from->cpt_si_pid; to->si_uid = from->cpt_si_uid; } if (to->si_code < 0) { to->si_pid = from->cpt_si_pid; to->si_uid = from->cpt_si_uid; to->si_ptr = (void *) (intptr_t) from->cpt_si_ptr; } else { switch (to->si_signo) { case SIGCHLD: to->si_pid = from->cpt_si_pid; to->si_uid = from->cpt_si_uid; to->si_status = from->cpt_si_status; to->si_utime = from->cpt_si_utime; to->si_stime = from->cpt_si_stime; break; case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: to->si_addr = (void *) (intptr_t) from->cpt_si_addr; break; case SIGPOLL: to->si_band = from->cpt_si_band; to->si_fd = from->cpt_si_fd; break; default: to->si_pid = from->cpt_si_pid; to->si_uid = from->cpt_si_uid; to->si_ptr = (void* ) (intptr_t) from->cpt_si_ptr; break; } } } /* Convert a native/host siginfo object, into/from the siginfo in the layout of the inferiors' architecture. Returns true if any conversion was done; false otherwise. If DIRECTION is 1, then copy from INF to NATIVE. If DIRECTION is 0, copy from NATIVE to INF. */ static int amd64_linux_siginfo_fixup (struct siginfo *native, gdb_byte *inf, int direction) { /* Is the inferior 32-bit? If so, then do fixup the siginfo object. */ if (gdbarch_addr_bit (get_frame_arch (get_current_frame ())) == 32) { gdb_assert (sizeof (struct siginfo) == sizeof (compat_siginfo_t)); if (direction == 0) compat_siginfo_from_siginfo ((struct compat_siginfo *) inf, native); else siginfo_from_compat_siginfo (native, (struct compat_siginfo *) inf); return 1; } else return 0; } /* Get Linux/x86 target description from running target. Value of CS segment register: 1. 64bit process: 0x33. 2. 32bit process: 0x23. */ #define AMD64_LINUX_USER64_CS 0x33 static const struct target_desc * amd64_linux_read_description (struct target_ops *ops) { unsigned long cs; int tid; int is_64bit; static uint64_t xcr0; /* GNU/Linux LWP ID's are process ID's. */ tid = TIDGET (inferior_ptid); if (tid == 0) tid = PIDGET (inferior_ptid); /* Not a threaded program. */ /* Get CS register. */ errno = 0; cs = ptrace (PTRACE_PEEKUSER, tid, offsetof (struct user_regs_struct, cs), 0); if (errno != 0) perror_with_name (_("Couldn't get CS register")); is_64bit = cs == AMD64_LINUX_USER64_CS; if (have_ptrace_getregset == -1) { uint64_t xstateregs[(I386_XSTATE_SSE_SIZE / sizeof (uint64_t))]; struct iovec iov; iov.iov_base = xstateregs; iov.iov_len = sizeof (xstateregs); /* Check if PTRACE_GETREGSET works. */ if (ptrace (PTRACE_GETREGSET, tid, (unsigned int) NT_X86_XSTATE, (long) &iov) < 0) have_ptrace_getregset = 0; else { have_ptrace_getregset = 1; /* Get XCR0 from XSAVE extended state. */ xcr0 = xstateregs[(I386_LINUX_XSAVE_XCR0_OFFSET / sizeof (uint64_t))]; } } /* Check the native XCR0 only if PTRACE_GETREGSET is available. */ if (have_ptrace_getregset && (xcr0 & I386_XSTATE_AVX_MASK) == I386_XSTATE_AVX_MASK) { if (is_64bit) return tdesc_amd64_avx_linux; else return tdesc_i386_avx_linux; } else { if (is_64bit) return tdesc_amd64_linux; else return tdesc_i386_linux; } } /* Provide a prototype to silence -Wmissing-prototypes. */ void _initialize_amd64_linux_nat (void); void _initialize_amd64_linux_nat (void) { struct target_ops *t; amd64_native_gregset32_reg_offset = amd64_linux_gregset32_reg_offset; amd64_native_gregset32_num_regs = I386_LINUX_NUM_REGS; amd64_native_gregset64_reg_offset = amd64_linux_gregset_reg_offset; amd64_native_gregset64_num_regs = AMD64_LINUX_NUM_REGS; gdb_assert (ARRAY_SIZE (amd64_linux_gregset32_reg_offset) == amd64_native_gregset32_num_regs); /* Fill in the generic GNU/Linux methods. */ t = linux_target (); i386_use_watchpoints (t); i386_dr_low.set_control = amd64_linux_dr_set_control; i386_dr_low.set_addr = amd64_linux_dr_set_addr; i386_dr_low.get_addr = amd64_linux_dr_get_addr; i386_dr_low.get_status = amd64_linux_dr_get_status; i386_dr_low.get_control = amd64_linux_dr_get_control; i386_set_debug_register_length (8); /* Override the GNU/Linux inferior startup hook. */ super_post_startup_inferior = t->to_post_startup_inferior; t->to_post_startup_inferior = amd64_linux_child_post_startup_inferior; /* Add our register access methods. */ t->to_fetch_registers = amd64_linux_fetch_inferior_registers; t->to_store_registers = amd64_linux_store_inferior_registers; t->to_read_description = amd64_linux_read_description; /* Register the target. */ linux_nat_add_target (t); linux_nat_set_new_thread (t, amd64_linux_new_thread); linux_nat_set_siginfo_fixup (t, amd64_linux_siginfo_fixup); linux_nat_set_prepare_to_resume (t, amd64_linux_prepare_to_resume); }