/gdb-linaro-dev/gdb/gdbserver/linux-x86-low.c
C | 3217 lines | 2567 code | 398 blank | 252 comment | 216 complexity | 1246ff3f5ff83516c045e12523599d66 MD5 | raw file
Possible License(s): BSD-3-Clause, GPL-2.0, LGPL-2.0, GPL-3.0, LGPL-2.1
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- /* GNU/Linux/x86-64 specific low level interface, for the remote server
- for GDB.
- Copyright (C) 2002-2013 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 <stddef.h>
- #include <signal.h>
- #include <limits.h>
- #include <inttypes.h>
- #include "server.h"
- #include "linux-low.h"
- #include "i387-fp.h"
- #include "i386-low.h"
- #include "i386-xstate.h"
- #include "elf/common.h"
- #include "gdb_proc_service.h"
- #include "agent.h"
- /* Defined in auto-generated file i386-linux.c. */
- void init_registers_i386_linux (void);
- /* Defined in auto-generated file amd64-linux.c. */
- void init_registers_amd64_linux (void);
- /* Defined in auto-generated file i386-avx-linux.c. */
- void init_registers_i386_avx_linux (void);
- /* Defined in auto-generated file amd64-avx-linux.c. */
- void init_registers_amd64_avx_linux (void);
- /* Defined in auto-generated file i386-mmx-linux.c. */
- void init_registers_i386_mmx_linux (void);
- /* Defined in auto-generated file x32-linux.c. */
- void init_registers_x32_linux (void);
- /* Defined in auto-generated file x32-avx-linux.c. */
- void init_registers_x32_avx_linux (void);
- static unsigned char jump_insn[] = { 0xe9, 0, 0, 0, 0 };
- static unsigned char small_jump_insn[] = { 0x66, 0xe9, 0, 0 };
- /* Backward compatibility for gdb without XML support. */
- static const char *xmltarget_i386_linux_no_xml = "@<target>\
- <architecture>i386</architecture>\
- <osabi>GNU/Linux</osabi>\
- </target>";
- #ifdef __x86_64__
- static const char *xmltarget_amd64_linux_no_xml = "@<target>\
- <architecture>i386:x86-64</architecture>\
- <osabi>GNU/Linux</osabi>\
- </target>";
- #endif
- #include <sys/reg.h>
- #include <sys/procfs.h>
- #include <sys/ptrace.h>
- #include <sys/uio.h>
- #ifndef PTRACE_GETREGSET
- #define PTRACE_GETREGSET 0x4204
- #endif
- #ifndef PTRACE_SETREGSET
- #define PTRACE_SETREGSET 0x4205
- #endif
- #ifndef PTRACE_GET_THREAD_AREA
- #define PTRACE_GET_THREAD_AREA 25
- #endif
- /* This definition comes from prctl.h, but some kernels may not have it. */
- #ifndef PTRACE_ARCH_PRCTL
- #define PTRACE_ARCH_PRCTL 30
- #endif
- /* The following definitions come from prctl.h, but may be absent
- for certain configurations. */
- #ifndef ARCH_GET_FS
- #define ARCH_SET_GS 0x1001
- #define ARCH_SET_FS 0x1002
- #define ARCH_GET_FS 0x1003
- #define ARCH_GET_GS 0x1004
- #endif
- /* Per-process arch-specific data we want to keep. */
- struct arch_process_info
- {
- struct i386_debug_reg_state debug_reg_state;
- };
- /* 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;
- };
- #ifdef __x86_64__
- /* Mapping between the general-purpose registers in `struct user'
- format and GDB's register array layout.
- Note that the transfer layout uses 64-bit regs. */
- static /*const*/ int i386_regmap[] =
- {
- RAX * 8, RCX * 8, RDX * 8, RBX * 8,
- RSP * 8, RBP * 8, RSI * 8, RDI * 8,
- RIP * 8, EFLAGS * 8, CS * 8, SS * 8,
- DS * 8, ES * 8, FS * 8, GS * 8
- };
- #define I386_NUM_REGS (sizeof (i386_regmap) / sizeof (i386_regmap[0]))
- /* So code below doesn't have to care, i386 or amd64. */
- #define ORIG_EAX ORIG_RAX
- static const int x86_64_regmap[] =
- {
- RAX * 8, RBX * 8, RCX * 8, RDX * 8,
- RSI * 8, RDI * 8, RBP * 8, RSP * 8,
- R8 * 8, R9 * 8, R10 * 8, R11 * 8,
- R12 * 8, R13 * 8, R14 * 8, R15 * 8,
- RIP * 8, EFLAGS * 8, CS * 8, SS * 8,
- DS * 8, ES * 8, FS * 8, GS * 8,
- -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
- };
- #define X86_64_NUM_REGS (sizeof (x86_64_regmap) / sizeof (x86_64_regmap[0]))
- #else /* ! __x86_64__ */
- /* Mapping between the general-purpose registers in `struct user'
- format and GDB's register array layout. */
- static /*const*/ int i386_regmap[] =
- {
- EAX * 4, ECX * 4, EDX * 4, EBX * 4,
- UESP * 4, EBP * 4, ESI * 4, EDI * 4,
- EIP * 4, EFL * 4, CS * 4, SS * 4,
- DS * 4, ES * 4, FS * 4, GS * 4
- };
- #define I386_NUM_REGS (sizeof (i386_regmap) / sizeof (i386_regmap[0]))
- #endif
- /* Called by libthread_db. */
- ps_err_e
- ps_get_thread_area (const struct ps_prochandle *ph,
- lwpid_t lwpid, int idx, void **base)
- {
- #ifdef __x86_64__
- int use_64bit = register_size (0) == 8;
- if (use_64bit)
- {
- 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:
- return PS_BADADDR;
- }
- return PS_ERR;
- }
- #endif
- {
- unsigned int desc[4];
- if (ptrace (PTRACE_GET_THREAD_AREA, lwpid,
- (void *) (intptr_t) idx, (unsigned long) &desc) < 0)
- return PS_ERR;
- *(int *)base = desc[1];
- return PS_OK;
- }
- }
- /* Get the thread area address. This is used to recognize which
- thread is which when tracing with the in-process agent library. We
- don't read anything from the address, and treat it as opaque; it's
- the address itself that we assume is unique per-thread. */
- static int
- x86_get_thread_area (int lwpid, CORE_ADDR *addr)
- {
- #ifdef __x86_64__
- int use_64bit = register_size (0) == 8;
- if (use_64bit)
- {
- void *base;
- if (ptrace (PTRACE_ARCH_PRCTL, lwpid, &base, ARCH_GET_FS) == 0)
- {
- *addr = (CORE_ADDR) (uintptr_t) base;
- return 0;
- }
- return -1;
- }
- #endif
- {
- struct lwp_info *lwp = find_lwp_pid (pid_to_ptid (lwpid));
- struct regcache *regcache = get_thread_regcache (get_lwp_thread (lwp), 1);
- unsigned int desc[4];
- ULONGEST gs = 0;
- const int reg_thread_area = 3; /* bits to scale down register value. */
- int idx;
- collect_register_by_name (regcache, "gs", &gs);
- idx = gs >> reg_thread_area;
- if (ptrace (PTRACE_GET_THREAD_AREA,
- lwpid_of (lwp),
- (void *) (long) idx, (unsigned long) &desc) < 0)
- return -1;
- *addr = desc[1];
- return 0;
- }
- }
- static int
- i386_cannot_store_register (int regno)
- {
- return regno >= I386_NUM_REGS;
- }
- static int
- i386_cannot_fetch_register (int regno)
- {
- return regno >= I386_NUM_REGS;
- }
- static void
- x86_fill_gregset (struct regcache *regcache, void *buf)
- {
- int i;
- #ifdef __x86_64__
- if (register_size (0) == 8)
- {
- for (i = 0; i < X86_64_NUM_REGS; i++)
- if (x86_64_regmap[i] != -1)
- collect_register (regcache, i, ((char *) buf) + x86_64_regmap[i]);
- return;
- }
- #endif
- for (i = 0; i < I386_NUM_REGS; i++)
- collect_register (regcache, i, ((char *) buf) + i386_regmap[i]);
- collect_register_by_name (regcache, "orig_eax",
- ((char *) buf) + ORIG_EAX * 4);
- }
- static void
- x86_store_gregset (struct regcache *regcache, const void *buf)
- {
- int i;
- #ifdef __x86_64__
- if (register_size (0) == 8)
- {
- for (i = 0; i < X86_64_NUM_REGS; i++)
- if (x86_64_regmap[i] != -1)
- supply_register (regcache, i, ((char *) buf) + x86_64_regmap[i]);
- return;
- }
- #endif
- for (i = 0; i < I386_NUM_REGS; i++)
- supply_register (regcache, i, ((char *) buf) + i386_regmap[i]);
- supply_register_by_name (regcache, "orig_eax",
- ((char *) buf) + ORIG_EAX * 4);
- }
- static void
- x86_fill_fpregset (struct regcache *regcache, void *buf)
- {
- #ifdef __x86_64__
- i387_cache_to_fxsave (regcache, buf);
- #else
- i387_cache_to_fsave (regcache, buf);
- #endif
- }
- static void
- x86_store_fpregset (struct regcache *regcache, const void *buf)
- {
- #ifdef __x86_64__
- i387_fxsave_to_cache (regcache, buf);
- #else
- i387_fsave_to_cache (regcache, buf);
- #endif
- }
- #ifndef __x86_64__
- static void
- x86_fill_fpxregset (struct regcache *regcache, void *buf)
- {
- i387_cache_to_fxsave (regcache, buf);
- }
- static void
- x86_store_fpxregset (struct regcache *regcache, const void *buf)
- {
- i387_fxsave_to_cache (regcache, buf);
- }
- #endif
- static void
- x86_fill_xstateregset (struct regcache *regcache, void *buf)
- {
- i387_cache_to_xsave (regcache, buf);
- }
- static void
- x86_store_xstateregset (struct regcache *regcache, const void *buf)
- {
- i387_xsave_to_cache (regcache, buf);
- }
- /* ??? The non-biarch i386 case stores all the i387 regs twice.
- Once in i387_.*fsave.* and once in i387_.*fxsave.*.
- This is, presumably, to handle the case where PTRACE_[GS]ETFPXREGS
- doesn't work. IWBN to avoid the duplication in the case where it
- does work. Maybe the arch_setup routine could check whether it works
- and update target_regsets accordingly, maybe by moving target_regsets
- to linux_target_ops and set the right one there, rather than having to
- modify the target_regsets global. */
- struct regset_info target_regsets[] =
- {
- #ifdef HAVE_PTRACE_GETREGS
- { PTRACE_GETREGS, PTRACE_SETREGS, 0, sizeof (elf_gregset_t),
- GENERAL_REGS,
- x86_fill_gregset, x86_store_gregset },
- { PTRACE_GETREGSET, PTRACE_SETREGSET, NT_X86_XSTATE, 0,
- EXTENDED_REGS, x86_fill_xstateregset, x86_store_xstateregset },
- # ifndef __x86_64__
- # ifdef HAVE_PTRACE_GETFPXREGS
- { PTRACE_GETFPXREGS, PTRACE_SETFPXREGS, 0, sizeof (elf_fpxregset_t),
- EXTENDED_REGS,
- x86_fill_fpxregset, x86_store_fpxregset },
- # endif
- # endif
- { PTRACE_GETFPREGS, PTRACE_SETFPREGS, 0, sizeof (elf_fpregset_t),
- FP_REGS,
- x86_fill_fpregset, x86_store_fpregset },
- #endif /* HAVE_PTRACE_GETREGS */
- { 0, 0, 0, -1, -1, NULL, NULL }
- };
- static CORE_ADDR
- x86_get_pc (struct regcache *regcache)
- {
- int use_64bit = register_size (0) == 8;
- if (use_64bit)
- {
- unsigned long pc;
- collect_register_by_name (regcache, "rip", &pc);
- return (CORE_ADDR) pc;
- }
- else
- {
- unsigned int pc;
- collect_register_by_name (regcache, "eip", &pc);
- return (CORE_ADDR) pc;
- }
- }
- static void
- x86_set_pc (struct regcache *regcache, CORE_ADDR pc)
- {
- int use_64bit = register_size (0) == 8;
- if (use_64bit)
- {
- unsigned long newpc = pc;
- supply_register_by_name (regcache, "rip", &newpc);
- }
- else
- {
- unsigned int newpc = pc;
- supply_register_by_name (regcache, "eip", &newpc);
- }
- }
- static const unsigned char x86_breakpoint[] = { 0xCC };
- #define x86_breakpoint_len 1
- static int
- x86_breakpoint_at (CORE_ADDR pc)
- {
- unsigned char c;
- (*the_target->read_memory) (pc, &c, 1);
- if (c == 0xCC)
- return 1;
- return 0;
- }
- /* Support for debug registers. */
- static unsigned long
- x86_linux_dr_get (ptid_t ptid, int regnum)
- {
- int tid;
- unsigned long value;
- tid = ptid_get_lwp (ptid);
- errno = 0;
- value = ptrace (PTRACE_PEEKUSER, tid,
- offsetof (struct user, u_debugreg[regnum]), 0);
- if (errno != 0)
- error ("Couldn't read debug register");
- return value;
- }
- static void
- x86_linux_dr_set (ptid_t ptid, int regnum, unsigned long value)
- {
- int tid;
- tid = ptid_get_lwp (ptid);
- errno = 0;
- ptrace (PTRACE_POKEUSER, tid,
- offsetof (struct user, u_debugreg[regnum]), value);
- if (errno != 0)
- error ("Couldn't write debug register");
- }
- static int
- update_debug_registers_callback (struct inferior_list_entry *entry,
- void *pid_p)
- {
- struct lwp_info *lwp = (struct lwp_info *) entry;
- int pid = *(int *) pid_p;
- /* Only update the threads of this process. */
- if (pid_of (lwp) == pid)
- {
- /* 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);
- }
- return 0;
- }
- /* Update the inferior's debug register REGNUM from STATE. */
- void
- i386_dr_low_set_addr (const struct i386_debug_reg_state *state, int regnum)
- {
- /* Only update the threads of this process. */
- int pid = pid_of (get_thread_lwp (current_inferior));
- if (! (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR))
- fatal ("Invalid debug register %d", regnum);
- find_inferior (&all_lwps, update_debug_registers_callback, &pid);
- }
- /* Return the inferior's debug register REGNUM. */
- CORE_ADDR
- i386_dr_low_get_addr (int regnum)
- {
- struct lwp_info *lwp = get_thread_lwp (current_inferior);
- ptid_t ptid = ptid_of (lwp);
- /* DR6 and DR7 are retrieved with some other way. */
- gdb_assert (DR_FIRSTADDR <= regnum && regnum <= DR_LASTADDR);
- return x86_linux_dr_get (ptid, regnum);
- }
- /* Update the inferior's DR7 debug control register from STATE. */
- void
- i386_dr_low_set_control (const struct i386_debug_reg_state *state)
- {
- /* Only update the threads of this process. */
- int pid = pid_of (get_thread_lwp (current_inferior));
- find_inferior (&all_lwps, update_debug_registers_callback, &pid);
- }
- /* Return the inferior's DR7 debug control register. */
- unsigned
- i386_dr_low_get_control (void)
- {
- struct lwp_info *lwp = get_thread_lwp (current_inferior);
- ptid_t ptid = ptid_of (lwp);
- return x86_linux_dr_get (ptid, DR_CONTROL);
- }
- /* Get the value of the DR6 debug status register from the inferior
- and record it in STATE. */
- unsigned
- i386_dr_low_get_status (void)
- {
- struct lwp_info *lwp = get_thread_lwp (current_inferior);
- ptid_t ptid = ptid_of (lwp);
- return x86_linux_dr_get (ptid, DR_STATUS);
- }
- /* Breakpoint/Watchpoint support. */
- static int
- x86_insert_point (char type, CORE_ADDR addr, int len)
- {
- struct process_info *proc = current_process ();
- switch (type)
- {
- case '0': /* software-breakpoint */
- {
- int ret;
- ret = prepare_to_access_memory ();
- if (ret)
- return -1;
- ret = set_gdb_breakpoint_at (addr);
- done_accessing_memory ();
- return ret;
- }
- case '1': /* hardware-breakpoint */
- case '2': /* write watchpoint */
- case '3': /* read watchpoint */
- case '4': /* access watchpoint */
- return i386_low_insert_watchpoint (&proc->private->arch_private->debug_reg_state,
- type, addr, len);
- default:
- /* Unsupported. */
- return 1;
- }
- }
- static int
- x86_remove_point (char type, CORE_ADDR addr, int len)
- {
- struct process_info *proc = current_process ();
- switch (type)
- {
- case '0': /* software-breakpoint */
- {
- int ret;
- ret = prepare_to_access_memory ();
- if (ret)
- return -1;
- ret = delete_gdb_breakpoint_at (addr);
- done_accessing_memory ();
- return ret;
- }
- case '1': /* hardware-breakpoint */
- case '2': /* write watchpoint */
- case '3': /* read watchpoint */
- case '4': /* access watchpoint */
- return i386_low_remove_watchpoint (&proc->private->arch_private->debug_reg_state,
- type, addr, len);
- default:
- /* Unsupported. */
- return 1;
- }
- }
- static int
- x86_stopped_by_watchpoint (void)
- {
- struct process_info *proc = current_process ();
- return i386_low_stopped_by_watchpoint (&proc->private->arch_private->debug_reg_state);
- }
- static CORE_ADDR
- x86_stopped_data_address (void)
- {
- struct process_info *proc = current_process ();
- CORE_ADDR addr;
- if (i386_low_stopped_data_address (&proc->private->arch_private->debug_reg_state,
- &addr))
- return addr;
- return 0;
- }
- /* Called when a new process is created. */
- static struct arch_process_info *
- x86_linux_new_process (void)
- {
- struct arch_process_info *info = xcalloc (1, sizeof (*info));
- i386_low_init_dregs (&info->debug_reg_state);
- return info;
- }
- /* Called when a new thread is detected. */
- static struct arch_lwp_info *
- x86_linux_new_thread (void)
- {
- struct arch_lwp_info *info = xcalloc (1, sizeof (*info));
- info->debug_registers_changed = 1;
- return info;
- }
- /* Called when resuming a thread.
- If the debug regs have changed, update the thread's copies. */
- static void
- x86_linux_prepare_to_resume (struct lwp_info *lwp)
- {
- ptid_t ptid = ptid_of (lwp);
- int clear_status = 0;
- if (lwp->arch_private->debug_registers_changed)
- {
- int i;
- int pid = ptid_get_pid (ptid);
- struct process_info *proc = find_process_pid (pid);
- struct i386_debug_reg_state *state
- = &proc->private->arch_private->debug_reg_state;
- for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
- if (state->dr_ref_count[i] > 0)
- {
- x86_linux_dr_set (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_low_stopped_data_address can
- get confused. */
- clear_status = 1;
- }
- x86_linux_dr_set (ptid, DR_CONTROL, state->dr_control_mirror);
- lwp->arch_private->debug_registers_changed = 0;
- }
- if (clear_status || lwp->stopped_by_watchpoint)
- x86_linux_dr_set (ptid, DR_STATUS, 0);
- }
- /* When GDBSERVER 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 GDBSERVER should look the same
- as debugging it with a 32-bit GDBSERVER, 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. */
- #ifdef __x86_64__
- 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;
- /* For x32, clock_t in _sigchld is 64bit aligned at 4 bytes. */
- typedef long __attribute__ ((__aligned__ (4))) compat_x32_clock_t;
- typedef struct compat_x32_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_x32_clock_t _utime;
- compat_x32_clock_t _stime;
- } _sigchld;
- /* SIGILL, SIGFPE, SIGSEGV, SIGBUS */
- struct
- {
- unsigned int _addr;
- } _sigfault;
- /* SIGPOLL */
- struct
- {
- int _band;
- int _fd;
- } _sigpoll;
- } _sifields;
- } compat_x32_siginfo_t __attribute__ ((__aligned__ (8)));
- #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;
- }
- else 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;
- }
- }
- }
- static void
- compat_x32_siginfo_from_siginfo (compat_x32_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_x32_siginfo (siginfo_t *to,
- compat_x32_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;
- }
- else 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;
- }
- }
- }
- /* Is this process 64-bit? */
- static int linux_is_elf64;
- #endif /* __x86_64__ */
- /* 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
- x86_siginfo_fixup (siginfo_t *native, void *inf, int direction)
- {
- #ifdef __x86_64__
- /* Is the inferior 32-bit? If so, then fixup the siginfo object. */
- if (register_size (0) == 4)
- {
- if (sizeof (siginfo_t) != sizeof (compat_siginfo_t))
- fatal ("unexpected difference in siginfo");
- if (direction == 0)
- compat_siginfo_from_siginfo ((struct compat_siginfo *) inf, native);
- else
- siginfo_from_compat_siginfo (native, (struct compat_siginfo *) inf);
- return 1;
- }
- /* No fixup for native x32 GDB. */
- else if (!linux_is_elf64 && sizeof (void *) == 8)
- {
- if (sizeof (siginfo_t) != sizeof (compat_x32_siginfo_t))
- fatal ("unexpected difference in siginfo");
- if (direction == 0)
- compat_x32_siginfo_from_siginfo ((struct compat_x32_siginfo *) inf,
- native);
- else
- siginfo_from_compat_x32_siginfo (native,
- (struct compat_x32_siginfo *) inf);
- return 1;
- }
- #endif
- return 0;
- }
- static int use_xml;
- /* Update gdbserver_xmltarget. */
- static void
- x86_linux_update_xmltarget (void)
- {
- int pid;
- struct regset_info *regset;
- static unsigned long long xcr0;
- static int have_ptrace_getregset = -1;
- #if !defined(__x86_64__) && defined(HAVE_PTRACE_GETFPXREGS)
- static int have_ptrace_getfpxregs = -1;
- #endif
- if (!current_inferior)
- return;
- /* Before changing the register cache internal layout or the target
- regsets, flush the contents of the current valid caches back to
- the threads. */
- regcache_invalidate ();
- pid = pid_of (get_thread_lwp (current_inferior));
- #ifdef __x86_64__
- if (num_xmm_registers == 8)
- init_registers_i386_linux ();
- else if (linux_is_elf64)
- init_registers_amd64_linux ();
- else
- init_registers_x32_linux ();
- #else
- {
- # ifdef HAVE_PTRACE_GETFPXREGS
- if (have_ptrace_getfpxregs == -1)
- {
- elf_fpxregset_t fpxregs;
- if (ptrace (PTRACE_GETFPXREGS, pid, 0, (int) &fpxregs) < 0)
- {
- have_ptrace_getfpxregs = 0;
- x86_xcr0 = I386_XSTATE_X87_MASK;
- /* Disable PTRACE_GETFPXREGS. */
- for (regset = target_regsets;
- regset->fill_function != NULL; regset++)
- if (regset->get_request == PTRACE_GETFPXREGS)
- {
- regset->size = 0;
- break;
- }
- }
- else
- have_ptrace_getfpxregs = 1;
- }
- if (!have_ptrace_getfpxregs)
- {
- init_registers_i386_mmx_linux ();
- return;
- }
- # endif
- init_registers_i386_linux ();
- }
- #endif
- if (!use_xml)
- {
- /* Don't use XML. */
- #ifdef __x86_64__
- if (num_xmm_registers == 8)
- gdbserver_xmltarget = xmltarget_i386_linux_no_xml;
- else
- gdbserver_xmltarget = xmltarget_amd64_linux_no_xml;
- #else
- gdbserver_xmltarget = xmltarget_i386_linux_no_xml;
- #endif
- x86_xcr0 = I386_XSTATE_SSE_MASK;
- return;
- }
- /* Check if XSAVE extended state is supported. */
- if (have_ptrace_getregset == -1)
- {
- unsigned long long xstateregs[I386_XSTATE_SSE_SIZE / sizeof (long long)];
- struct iovec iov;
- iov.iov_base = xstateregs;
- iov.iov_len = sizeof (xstateregs);
- /* Check if PTRACE_GETREGSET works. */
- if (ptrace (PTRACE_GETREGSET, pid, (unsigned int) NT_X86_XSTATE,
- &iov) < 0)
- {
- have_ptrace_getregset = 0;
- return;
- }
- else
- have_ptrace_getregset = 1;
- /* Get XCR0 from XSAVE extended state at byte 464. */
- xcr0 = xstateregs[464 / sizeof (long long)];
- /* Use PTRACE_GETREGSET if it is available. */
- for (regset = target_regsets;
- regset->fill_function != NULL; regset++)
- if (regset->get_request == PTRACE_GETREGSET)
- regset->size = I386_XSTATE_SIZE (xcr0);
- else if (regset->type != GENERAL_REGS)
- regset->size = 0;
- }
- if (have_ptrace_getregset)
- {
- /* AVX is the highest feature we support. */
- if ((xcr0 & I386_XSTATE_AVX_MASK) == I386_XSTATE_AVX_MASK)
- {
- x86_xcr0 = xcr0;
- #ifdef __x86_64__
- /* I386 has 8 xmm regs. */
- if (num_xmm_registers == 8)
- init_registers_i386_avx_linux ();
- else if (linux_is_elf64)
- init_registers_amd64_avx_linux ();
- else
- init_registers_x32_avx_linux ();
- #else
- init_registers_i386_avx_linux ();
- #endif
- }
- }
- }
- /* Process qSupported query, "xmlRegisters=". Update the buffer size for
- PTRACE_GETREGSET. */
- static void
- x86_linux_process_qsupported (const char *query)
- {
- /* Return if gdb doesn't support XML. If gdb sends "xmlRegisters="
- with "i386" in qSupported query, it supports x86 XML target
- descriptions. */
- use_xml = 0;
- if (query != NULL && strncmp (query, "xmlRegisters=", 13) == 0)
- {
- char *copy = xstrdup (query + 13);
- char *p;
- for (p = strtok (copy, ","); p != NULL; p = strtok (NULL, ","))
- {
- if (strcmp (p, "i386") == 0)
- {
- use_xml = 1;
- break;
- }
- }
- free (copy);
- }
- x86_linux_update_xmltarget ();
- }
- /* Initialize gdbserver for the architecture of the inferior. */
- static void
- x86_arch_setup (void)
- {
- int pid = pid_of (get_thread_lwp (current_inferior));
- unsigned int machine;
- int is_elf64 = linux_pid_exe_is_elf_64_file (pid, &machine);
- if (sizeof (void *) == 4)
- {
- if (is_elf64 > 0)
- error (_("Can't debug 64-bit process with 32-bit GDBserver"));
- #ifndef __x86_64__
- else if (machine == EM_X86_64)
- error (_("Can't debug x86-64 process with 32-bit GDBserver"));
- #endif
- }
- #ifdef __x86_64__
- if (is_elf64 < 0)
- {
- /* This can only happen if /proc/<pid>/exe is unreadable,
- but "that can't happen" if we've gotten this far.
- Fall through and assume this is a 32-bit program. */
- }
- else if (machine == EM_X86_64)
- {
- /* Amd64 doesn't have HAVE_LINUX_USRREGS. */
- the_low_target.num_regs = -1;
- the_low_target.regmap = NULL;
- the_low_target.cannot_fetch_register = NULL;
- the_low_target.cannot_store_register = NULL;
- /* Amd64 has 16 xmm regs. */
- num_xmm_registers = 16;
- linux_is_elf64 = is_elf64;
- x86_linux_update_xmltarget ();
- return;
- }
- linux_is_elf64 = 0;
- #endif
- /* Ok we have a 32-bit inferior. */
- the_low_target.num_regs = I386_NUM_REGS;
- the_low_target.regmap = i386_regmap;
- the_low_target.cannot_fetch_register = i386_cannot_fetch_register;
- the_low_target.cannot_store_register = i386_cannot_store_register;
- /* I386 has 8 xmm regs. */
- num_xmm_registers = 8;
- x86_linux_update_xmltarget ();
- }
- static int
- x86_supports_tracepoints (void)
- {
- return 1;
- }
- static void
- append_insns (CORE_ADDR *to, size_t len, const unsigned char *buf)
- {
- write_inferior_memory (*to, buf, len);
- *to += len;
- }
- static int
- push_opcode (unsigned char *buf, char *op)
- {
- unsigned char *buf_org = buf;
- while (1)
- {
- char *endptr;
- unsigned long ul = strtoul (op, &endptr, 16);
- if (endptr == op)
- break;
- *buf++ = ul;
- op = endptr;
- }
- return buf - buf_org;
- }
- #ifdef __x86_64__
- /* Build a jump pad that saves registers and calls a collection
- function. Writes a jump instruction to the jump pad to
- JJUMPAD_INSN. The caller is responsible to write it in at the
- tracepoint address. */
- static int
- amd64_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
- CORE_ADDR collector,
- CORE_ADDR lockaddr,
- ULONGEST orig_size,
- CORE_ADDR *jump_entry,
- CORE_ADDR *trampoline,
- ULONGEST *trampoline_size,
- unsigned char *jjump_pad_insn,
- ULONGEST *jjump_pad_insn_size,
- CORE_ADDR *adjusted_insn_addr,
- CORE_ADDR *adjusted_insn_addr_end,
- char *err)
- {
- unsigned char buf[40];
- int i, offset;
- int64_t loffset;
- CORE_ADDR buildaddr = *jump_entry;
- /* Build the jump pad. */
- /* First, do tracepoint data collection. Save registers. */
- i = 0;
- /* Need to ensure stack pointer saved first. */
- buf[i++] = 0x54; /* push %rsp */
- buf[i++] = 0x55; /* push %rbp */
- buf[i++] = 0x57; /* push %rdi */
- buf[i++] = 0x56; /* push %rsi */
- buf[i++] = 0x52; /* push %rdx */
- buf[i++] = 0x51; /* push %rcx */
- buf[i++] = 0x53; /* push %rbx */
- buf[i++] = 0x50; /* push %rax */
- buf[i++] = 0x41; buf[i++] = 0x57; /* push %r15 */
- buf[i++] = 0x41; buf[i++] = 0x56; /* push %r14 */
- buf[i++] = 0x41; buf[i++] = 0x55; /* push %r13 */
- buf[i++] = 0x41; buf[i++] = 0x54; /* push %r12 */
- buf[i++] = 0x41; buf[i++] = 0x53; /* push %r11 */
- buf[i++] = 0x41; buf[i++] = 0x52; /* push %r10 */
- buf[i++] = 0x41; buf[i++] = 0x51; /* push %r9 */
- buf[i++] = 0x41; buf[i++] = 0x50; /* push %r8 */
- buf[i++] = 0x9c; /* pushfq */
- buf[i++] = 0x48; /* movl <addr>,%rdi */
- buf[i++] = 0xbf;
- *((unsigned long *)(buf + i)) = (unsigned long) tpaddr;
- i += sizeof (unsigned long);
- buf[i++] = 0x57; /* push %rdi */
- append_insns (&buildaddr, i, buf);
- /* Stack space for the collecting_t object. */
- i = 0;
- i += push_opcode (&buf[i], "48 83 ec 18"); /* sub $0x18,%rsp */
- i += push_opcode (&buf[i], "48 b8"); /* mov <tpoint>,%rax */
- memcpy (buf + i, &tpoint, 8);
- i += 8;
- i += push_opcode (&buf[i], "48 89 04 24"); /* mov %rax,(%rsp) */
- i += push_opcode (&buf[i],
- "64 48 8b 04 25 00 00 00 00"); /* mov %fs:0x0,%rax */
- i += push_opcode (&buf[i], "48 89 44 24 08"); /* mov %rax,0x8(%rsp) */
- append_insns (&buildaddr, i, buf);
- /* spin-lock. */
- i = 0;
- i += push_opcode (&buf[i], "48 be"); /* movl <lockaddr>,%rsi */
- memcpy (&buf[i], (void *) &lockaddr, 8);
- i += 8;
- i += push_opcode (&buf[i], "48 89 e1"); /* mov %rsp,%rcx */
- i += push_opcode (&buf[i], "31 c0"); /* xor %eax,%eax */
- i += push_opcode (&buf[i], "f0 48 0f b1 0e"); /* lock cmpxchg %rcx,(%rsi) */
- i += push_opcode (&buf[i], "48 85 c0"); /* test %rax,%rax */
- i += push_opcode (&buf[i], "75 f4"); /* jne <again> */
- append_insns (&buildaddr, i, buf);
- /* Set up the gdb_collect call. */
- /* At this point, (stack pointer + 0x18) is the base of our saved
- register block. */
- i = 0;
- i += push_opcode (&buf[i], "48 89 e6"); /* mov %rsp,%rsi */
- i += push_opcode (&buf[i], "48 83 c6 18"); /* add $0x18,%rsi */
- /* tpoint address may be 64-bit wide. */
- i += push_opcode (&buf[i], "48 bf"); /* movl <addr>,%rdi */
- memcpy (buf + i, &tpoint, 8);
- i += 8;
- append_insns (&buildaddr, i, buf);
- /* The collector function being in the shared library, may be
- >31-bits away off the jump pad. */
- i = 0;
- i += push_opcode (&buf[i], "48 b8"); /* mov $collector,%rax */
- memcpy (buf + i, &collector, 8);
- i += 8;
- i += push_opcode (&buf[i], "ff d0"); /* callq *%rax */
- append_insns (&buildaddr, i, buf);
- /* Clear the spin-lock. */
- i = 0;
- i += push_opcode (&buf[i], "31 c0"); /* xor %eax,%eax */
- i += push_opcode (&buf[i], "48 a3"); /* mov %rax, lockaddr */
- memcpy (buf + i, &lockaddr, 8);
- i += 8;
- append_insns (&buildaddr, i, buf);
- /* Remove stack that had been used for the collect_t object. */
- i = 0;
- i += push_opcode (&buf[i], "48 83 c4 18"); /* add $0x18,%rsp */
- append_insns (&buildaddr, i, buf);
- /* Restore register state. */
- i = 0;
- buf[i++] = 0x48; /* add $0x8,%rsp */
- buf[i++] = 0x83;
- buf[i++] = 0xc4;
- buf[i++] = 0x08;
- buf[i++] = 0x9d; /* popfq */
- buf[i++] = 0x41; buf[i++] = 0x58; /* pop %r8 */
- buf[i++] = 0x41; buf[i++] = 0x59; /* pop %r9 */
- buf[i++] = 0x41; buf[i++] = 0x5a; /* pop %r10 */
- buf[i++] = 0x41; buf[i++] = 0x5b; /* pop %r11 */
- buf[i++] = 0x41; buf[i++] = 0x5c; /* pop %r12 */
- buf[i++] = 0x41; buf[i++] = 0x5d; /* pop %r13 */
- buf[i++] = 0x41; buf[i++] = 0x5e; /* pop %r14 */
- buf[i++] = 0x41; buf[i++] = 0x5f; /* pop %r15 */
- buf[i++] = 0x58; /* pop %rax */
- buf[i++] = 0x5b; /* pop %rbx */
- buf[i++] = 0x59; /* pop %rcx */
- buf[i++] = 0x5a; /* pop %rdx */
- buf[i++] = 0x5e; /* pop %rsi */
- buf[i++] = 0x5f; /* pop %rdi */
- buf[i++] = 0x5d; /* pop %rbp */
- buf[i++] = 0x5c; /* pop %rsp */
- append_insns (&buildaddr, i, buf);
- /* Now, adjust the original instruction to execute in the jump
- pad. */
- *adjusted_insn_addr = buildaddr;
- relocate_instruction (&buildaddr, tpaddr);
- *adjusted_insn_addr_end = buildaddr;
- /* Finally, write a jump back to the program. */
- loffset = (tpaddr + orig_size) - (buildaddr + sizeof (jump_insn));
- if (loffset > INT_MAX || loffset < INT_MIN)
- {
- sprintf (err,
- "E.Jump back from jump pad too far from tracepoint "
- "(offset 0x%" PRIx64 " > int32).", loffset);
- return 1;
- }
- offset = (int) loffset;
- memcpy (buf, jump_insn, sizeof (jump_insn));
- memcpy (buf + 1, &offset, 4);
- append_insns (&buildaddr, sizeof (jump_insn), buf);
- /* The jump pad is now built. Wire in a jump to our jump pad. This
- is always done last (by our caller actually), so that we can
- install fast tracepoints with threads running. This relies on
- the agent's atomic write support. */
- loffset = *jump_entry - (tpaddr + sizeof (jump_insn));
- if (loffset > INT_MAX || loffset < INT_MIN)
- {
- sprintf (err,
- "E.Jump pad too far from tracepoint "
- "(offset 0x%" PRIx64 " > int32).", loffset);
- return 1;
- }
- offset = (int) loffset;
- memcpy (buf, jump_insn, sizeof (jump_insn));
- memcpy (buf + 1, &offset, 4);
- memcpy (jjump_pad_insn, buf, sizeof (jump_insn));
- *jjump_pad_insn_size = sizeof (jump_insn);
- /* Return the end address of our pad. */
- *jump_entry = buildaddr;
- return 0;
- }
- #endif /* __x86_64__ */
- /* Build a jump pad that saves registers and calls a collection
- function. Writes a jump instruction to the jump pad to
- JJUMPAD_INSN. The caller is responsible to write it in at the
- tracepoint address. */
- static int
- i386_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
- CORE_ADDR collector,
- CORE_ADDR lockaddr,
- ULONGEST orig_size,
- CORE_ADDR *jump_entry,
- CORE_ADDR *trampoline,
- ULONGEST *trampoline_size,
- unsigned char *jjump_pad_insn,
- ULONGEST *jjump_pad_insn_size,
- CORE_ADDR *adjusted_insn_addr,
- CORE_ADDR *adjusted_insn_addr_end,
- char *err)
- {
- unsigned char buf[0x100];
- int i, offset;
- CORE_ADDR buildaddr = *jump_entry;
- /* Build the jump pad. */
- /* First, do tracepoint data collection. Save registers. */
- i = 0;
- buf[i++] = 0x60; /* pushad */
- buf[i++] = 0x68; /* push tpaddr aka $pc */
- *((int *)(buf + i)) = (int) tpaddr;
- i += 4;
- buf[i++] = 0x9c; /* pushf */
- buf[i++] = 0x1e; /* push %ds */
- buf[i++] = 0x06; /* push %es */
- buf[i++] = 0x0f; /* push %fs */
- buf[i++] = 0xa0;
- buf[i++] = 0x0f; /* push %gs */
- buf[i++] = 0xa8;
- buf[i++] = 0x16; /* push %ss */
- buf[i++] = 0x0e; /* push %cs */
- append_insns (&buildaddr, i, buf);
- /* Stack space for the collecting_t object. */
- i = 0;
- i += push_opcode (&buf[i], "83 ec 08"); /* sub $0x8,%esp */
- /* Build the object. */
- i += push_opcode (&buf[i], "b8"); /* mov <tpoint>,%eax */
- memcpy (buf + i, &tpoint, 4);
- i += 4;
- i += push_opcode (&buf[i], "89 04 24"); /* mov %eax,(%esp) */
- i += push_opcode (&buf[i], "65 a1 00 00 00 00"); /* mov %gs:0x0,%eax */
- i += push_opcode (&buf[i], "89 44 24 04"); /* mov %eax,0x4(%esp) */
- append_insns (&buildaddr, i, buf);
- /* spin-lock. Note this is using cmpxchg, which leaves i386 behind.
- If we cared for it, this could be using xchg alternatively. */
- i = 0;
- i += push_opcode (&buf[i], "31 c0"); /* xor %eax,%eax */
- i += push_opcode (&buf[i], "f0 0f b1 25"); /* lock cmpxchg
- %esp,<lockaddr> */
- memcpy (&buf[i], (void *) &lockaddr, 4);
- i += 4;
- i += push_opcode (&buf[i], "85 c0"); /* test %eax,%eax */
- i += push_opcode (&buf[i], "75 f2"); /* jne <again> */
- append_insns (&buildaddr, i, buf);
- /* Set up arguments to the gdb_collect call. */
- i = 0;
- i += push_opcode (&buf[i], "89 e0"); /* mov %esp,%eax */
- i += push_opcode (&buf[i], "83 c0 08"); /* add $0x08,%eax */
- i += push_opcode (&buf[i], "89 44 24 fc"); /* mov %eax,-0x4(%esp) */
- append_insns (&buildaddr, i, buf);
- i = 0;
- i += push_opcode (&buf[i], "83 ec 08"); /* sub $0x8,%esp */
- append_insns (&buildaddr, i, buf);
- i = 0;
- i += push_opcode (&buf[i], "c7 04 24"); /* movl <addr>,(%esp) */
- memcpy (&buf[i], (void *) &tpoint, 4);
- i += 4;
- append_insns (&buildaddr, i, buf);
- buf[0] = 0xe8; /* call <reladdr> */
- offset = collector - (buildaddr + sizeof (jump_insn));
- memcpy (buf + 1, &offset, 4);
- append_insns (&buildaddr, 5, buf);
- /* Clean up after the call. */
- buf[0] = 0x83; /* add $0x8,%esp */
- buf[1] = 0xc4;
- buf[2] = 0x08;
- append_insns (&buildaddr, 3, buf);
- /* Clear the spin-lock. This would need the LOCK prefix on older
- broken archs. */
- i = 0;
- i += push_opcode (&buf[i], "31 c0"); /* xor %eax,%eax */
- i += push_opcode (&buf[i], "a3"); /* mov %eax, lockaddr */
- memcpy (buf + i, &lockaddr, 4);
- i += 4;
- append_insns (&buildaddr, i, buf);
- /* Remove stack that had been used for the collect_t object. */
- i = 0;
- i += push_opcode (&buf[i], "83 c4 08"); /* add $0x08,%esp */
- append_insns (&buildaddr, i, buf);
- i = 0;
- buf[i++] = 0x83; /* add $0x4,%esp (no pop of %cs, assume unchanged) */
- buf[i++] = 0xc4;
- buf[i++] = 0x04;
- buf[i++] = 0x17; /* pop %ss */
- buf[i++] = 0x0f; /* pop %gs */
- buf[i++] = 0xa9;
- buf[i++] = 0x0f; /* pop %fs */
- buf[i++] = 0xa1;
- buf[i++] = 0x07; /* pop %es */
- buf[i++] = 0x1f; /* pop %ds */
- buf[i++] = 0x9d; /* popf */
- buf[i++] = 0x83; /* add $0x4,%esp (pop of tpaddr aka $pc) */
- buf[i++] = 0xc4;
- buf[i++] = 0x04;
- buf[i++] = 0x61; /* popad */
- append_insns (&buildaddr, i, buf);
- /* Now, adjust the original instruction to execute in the jump
- pad. */
- *adjusted_insn_addr = buildaddr;
- relocate_instruction (&buildaddr, tpaddr);
- *adjusted_insn_addr_end = buildaddr;
- /* Write the jump back to the program. */
- offset = (tpaddr + orig_size) - (buildaddr + sizeof (jump_insn));
- memcpy (buf, jump_insn, sizeof (jump_insn));
- memcpy (buf + 1, &offset, 4);
- append_insns (&buildaddr, sizeof (jump_insn), buf);
- /* The jump pad is now built. Wire in a jump to our jump pad. This
- is always done last (by our caller actually), so that we can
- install fast tracepoints with threads running. This relies on
- the agent's atomic write support. */
- if (orig_size == 4)
- {
- /* Create a trampoline. */
- *trampoline_size = sizeof (jump_insn);
- if (!claim_trampoline_space (*trampoline_size, trampoline))
- {
- /* No trampoline space available. */
- strcpy (err,
- "E.Cannot allocate trampoline space needed for fast "
- "tracepoints on 4-byte instructions.");
- return 1;
- }
- offset = *jump_entry - (*trampoline + sizeof (jump_insn));
- memcpy (buf, jump_insn, sizeof (jump_insn));
- memcpy (buf + 1, &offset, 4);
- write_inferior_memory (*trampoline, buf, sizeof (jump_insn));
- /* Use a 16-bit relative jump instruction to jump to the trampoline. */
- offset = (*trampoline - (tpaddr + sizeof (small_jump_insn))) & 0xffff;
- memcpy (buf, small_jump_insn, sizeof (small_jump_insn));
- memcpy (buf + 2, &offset, 2);
- memcpy (jjump_pad_insn, buf, sizeof (small_jump_insn));
- *jjump_pad_insn_size = sizeof (small_jump_insn);
- }
- else
- {
- /* Else use a 32-bit relative jump instruction. */
- offset = *jump_entry - (tpaddr + sizeof (jump_insn));
- memcpy (buf, jump_insn, sizeof (jump_insn));
- memcpy (buf + 1, &offset, 4);
- memcpy (jjump_pad_insn, buf, sizeof (jump_insn));
- *jjump_pad_insn_size = sizeof (jump_insn);
- }
- /* Return the end address of our pad. */
- *jump_entry = buildaddr;
- return 0;
- }
- static int
- x86_install_fast_tracepoint_jump_pad (CORE_ADDR tpoint, CORE_ADDR tpaddr,
- CORE_ADDR collector,
- CORE_ADDR lockaddr,
- ULONGEST orig_size,
- CORE_ADDR *jump_entry,
- CORE_ADDR *trampoline,
- ULONGEST *trampoline_size,
- unsigned char *jjump_pad_insn,
- ULONGEST *jjump_pad_insn_size,
- CORE_ADDR *adjusted_insn_addr,
- CORE_ADDR *adjusted_insn_addr_end,
- char *err)
- {
- #ifdef __x86_64__
- if (register_size (0) == 8)
- return amd64_install_fast_tracepoint_jump_pad (tpoint, tpaddr,
- collector, lockaddr,
- orig_size, jump_entry,
- trampoline, trampoline_size,
- jjump_pad_insn,
- jjump_pad_insn_size,
- adjusted_insn_addr,
- adjusted_insn_addr_end,
- err);
- #endif
- return i386_install_fast_tracepoint_jump_pad (tpoint, tpaddr,
- collector, lockaddr,
- orig_size, jump_entry,
- trampoline, trampoline_size,
- jjump_pad_insn,
- jjump_pad_insn_size,
- adjusted_insn_addr,
- adjusted_insn_addr_end,
- err);
- }
- /* Return the minimum instruction length for fast tracepoints on x86/x86-64
- architectures. */
- static int
- x86_get_min_fast_tracepoint_insn_len (void)
- {
- static int warned_about_fast_tracepoints = 0;
- #ifdef __x86_64__
- /* On x86-64, 5-byte jump instructions with a 4-byte offset are always
- used for fast tracepoints. */
- if (register_size (0) == 8)
- return 5;
- #endif
- if (agent_loaded_p ())
- {
- char errbuf[IPA_BUFSIZ];
- errbuf[0] = '\0';
- /* On x86, if trampolines are available, then 4-byte jump instructions
- with a 2-byte offset may be used, otherwise 5-byte jump instructions
- with a 4-byte offset are used instead. */
- if (have_fast_tracepoint_trampoline_buffer (errbuf))
- return 4;
- else
- {
- /* GDB has no channel to explain to user why a shorter fast
- tracepoint is not possible, but at least make GDBserver
- mention that something has gone awry. */
- if (!warned_about_fast_tracepoints)
- {
- warning ("4-byte fast tracepoints not available; %s\n", errbuf);
- warned_about_fast_tracepoints = 1;
- }
- return 5;
- }
- }
- else
- {
- /* Indicate that the minimum length is currently unknown since the IPA
- has not loaded yet. */
- return 0;
- }
- }
- static void
- add_insns (unsigned char *start, int len)
- {
- CORE_ADDR buildaddr = current_insn_ptr;
- if (debug_threads)
- fprintf (stderr, "Adding %d bytes of insn at %s\n",
- len, paddress (buildaddr));
- append_insns (&buildaddr, len, start);
- current_insn_ptr = buildaddr;
- }
- /* Our general strategy for emitting code is to avoid specifying raw
- bytes whenever possible, and instead copy a block of inline asm
- that is embedded in the function. This is a little messy, because
- we need to keep the compiler from discarding what looks like dead
- code, plus suppress various warnings. */
- #define EMIT_ASM(NAME, INSNS) \
- do \
- { \
- extern unsigned char start_ ## NAME, end_ ## NAME; \
- add_insns (&start_ ## NAME, &end_ ## NAME - &start_ ## NAME); \
- __asm__ ("jmp end_" #NAME "\n" \
- "\t" "start_" #NAME ":" \
- "\t" INSNS "\n" \
- "\t" "end_" #NAME ":"); \
- } while (0)
- #ifdef __x86_64__
- #define EMIT_ASM32(NAME,INSNS) \
- do \
- { \
- extern unsigned char start_ ## NAME, end_ ## NAME; \
- add_insns (&start_ ## NAME, &end_ ## NAME - &start_ ## NAME); \
- __asm__ (".code32\n" \
- "\t" "jmp end_" #NAME "\n" \
- "\t" "start_" #NAME ":\n" \
- "\t" INSNS "\n" \
- "\t" "end_" #NAME ":\n" \
- ".code64\n"); \
- } while (0)
- #else
- #define EMIT_ASM32(NAME,INSNS) EMIT_ASM(NAME,INSNS)
- #endif
- #ifdef __x86_64__
- static void
- amd64_emit_prologue (void)
- {
- EMIT_ASM (amd64_prologue,
- "pushq %rbp\n\t"
- "movq %rsp,%rbp\n\t"
- "sub $0x20,%rsp\n\t"
- "movq %rdi,-8(%rbp)\n\t"
- "movq %rsi,-16(%rbp)");
- }
- static void
- amd64_emit_epilogue (void)
- {
- EMIT_ASM (amd64_epilogue,
- "…
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