/* GNU/Linux/x86-64 specific low level interface, for the remote server
for GDB.
- Copyright (C) 2002, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
- Free Software Foundation, Inc.
+ Copyright (C) 2002-2013 Free Software Foundation, Inc.
This file is part of GDB.
#include <stddef.h>
#include <signal.h>
#include <limits.h>
+#include <inttypes.h>
#include "server.h"
#include "linux-low.h"
#include "i387-fp.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);
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. */
struct process_info *proc = current_process ();
switch (type)
{
- case '0':
+ case '0': /* software-breakpoint */
{
int ret;
done_accessing_memory ();
return ret;
}
- case '2':
- case '3':
- case '4':
+ 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;
struct process_info *proc = current_process ();
switch (type)
{
- case '0':
+ case '0': /* software-breakpoint */
{
int ret;
done_accessing_memory ();
return ret;
}
- case '2':
- case '3':
- case '4':
+ 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:
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)
{
= &proc->private->arch_private->debug_reg_state;
for (i = DR_FIRSTADDR; i <= DR_LASTADDR; i++)
- x86_linux_dr_set (ptid, i, state->dr_mirror[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 (lwp->stopped_by_watchpoint)
+ if (clear_status || lwp->stopped_by_watchpoint)
x86_linux_dr_set (ptid, DR_STATUS, 0);
}
\f
} _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
}
}
+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
INF. */
static int
-x86_siginfo_fixup (struct siginfo *native, void *inf, int direction)
+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 (struct siginfo) != sizeof (compat_siginfo_t))
+ if (sizeof (siginfo_t) != sizeof (compat_siginfo_t))
fatal ("unexpected difference in siginfo");
if (direction == 0)
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
#ifdef __x86_64__
if (num_xmm_registers == 8)
init_registers_i386_linux ();
- else
+ else if (linux_is_elf64)
init_registers_amd64_linux ();
+ else
+ init_registers_x32_linux ();
#else
{
# ifdef HAVE_PTRACE_GETFPXREGS
/* I386 has 8 xmm regs. */
if (num_xmm_registers == 8)
init_registers_i386_avx_linux ();
- else
+ else if (linux_is_elf64)
init_registers_amd64_avx_linux ();
+ else
+ init_registers_x32_avx_linux ();
#else
init_registers_i386_avx_linux ();
#endif
static void
x86_arch_setup (void)
{
-#ifdef __x86_64__
int pid = pid_of (get_thread_lwp (current_inferior));
- char *file = linux_child_pid_to_exec_file (pid);
- int use_64bit = elf_64_file_p (file);
+ unsigned int machine;
+ int is_elf64 = linux_pid_exe_is_elf_64_file (pid, &machine);
- free (file);
+ 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
+ }
- if (use_64bit < 0)
+#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 (use_64bit)
+ else if (machine == EM_X86_64)
{
/* Amd64 doesn't have HAVE_LINUX_USRREGS. */
the_low_target.num_regs = -1;
/* 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. */
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)
+ 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. */
*adjusted_insn_addr_end = buildaddr;
/* Finally, write a jump back to the program. */
- offset = (tpaddr + orig_size) - (buildaddr + sizeof (jump_insn));
+
+ 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);
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. */
- offset = *jump_entry - (tpaddr + sizeof (jump_insn));
+ 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));
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)
+ CORE_ADDR *adjusted_insn_addr_end,
+ char *err)
{
unsigned char buf[0x100];
int i, offset;
buf[i++] = 0x0f; /* pop %fs */
buf[i++] = 0xa1;
buf[i++] = 0x07; /* pop %es */
- buf[i++] = 0x1f; /* pop %de */
+ buf[i++] = 0x1f; /* pop %ds */
buf[i++] = 0x9d; /* popf */
buf[i++] = 0x83; /* add $0x4,%esp (pop of tpaddr aka $pc) */
buf[i++] = 0xc4;
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. */
- 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);
+ 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;
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)
+ 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);
+ 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);
+ 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
NULL,
NULL,
NULL,
+ NULL,
+ NULL, /* fetch_register */
x86_get_pc,
x86_set_pc,
x86_breakpoint,
x86_supports_tracepoints,
x86_get_thread_area,
x86_install_fast_tracepoint_jump_pad,
- x86_emit_ops
+ x86_emit_ops,
+ x86_get_min_fast_tracepoint_insn_len,
};