mirror of
https://sourceware.org/git/binutils-gdb.git
synced 2024-11-28 04:25:10 +08:00
400 lines
11 KiB
C
400 lines
11 KiB
C
/* Native-dependent code for GNU/Linux x86 (i386 and x86-64).
|
||
|
||
Copyright (C) 1999-2016 Free Software Foundation, Inc.
|
||
|
||
This file is part of GDB.
|
||
|
||
This program is free software; you can redistribute it and/or modify
|
||
it under the terms of the GNU General Public License as published by
|
||
the Free Software Foundation; either version 3 of the License, or
|
||
(at your option) any later version.
|
||
|
||
This program is distributed in the hope that it will be useful,
|
||
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||
GNU General Public License for more details.
|
||
|
||
You should have received a copy of the GNU General Public License
|
||
along with this program. If not, see <http://www.gnu.org/licenses/>. */
|
||
|
||
#include "defs.h"
|
||
#include "inferior.h"
|
||
#include "elf/common.h"
|
||
#include "gdb_proc_service.h"
|
||
#include "nat/gdb_ptrace.h"
|
||
#include <sys/user.h>
|
||
#include <sys/procfs.h>
|
||
#include <sys/uio.h>
|
||
|
||
#include "x86-nat.h"
|
||
#include "linux-nat.h"
|
||
#ifndef __x86_64__
|
||
#include "i386-linux-nat.h"
|
||
#endif
|
||
#include "x86-linux-nat.h"
|
||
#include "i386-linux-tdep.h"
|
||
#ifdef __x86_64__
|
||
#include "amd64-linux-tdep.h"
|
||
#endif
|
||
#include "x86-xstate.h"
|
||
#include "nat/linux-btrace.h"
|
||
#include "nat/linux-nat.h"
|
||
#include "nat/x86-linux.h"
|
||
#include "nat/x86-linux-dregs.h"
|
||
#include "nat/linux-ptrace.h"
|
||
|
||
/* 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;
|
||
};
|
||
|
||
|
||
|
||
/* linux_nat_new_fork hook. */
|
||
|
||
static void
|
||
x86_linux_new_fork (struct lwp_info *parent, pid_t child_pid)
|
||
{
|
||
pid_t parent_pid;
|
||
struct x86_debug_reg_state *parent_state;
|
||
struct x86_debug_reg_state *child_state;
|
||
|
||
/* NULL means no watchpoint has ever been set in the parent. In
|
||
that case, there's nothing to do. */
|
||
if (parent->arch_private == NULL)
|
||
return;
|
||
|
||
/* Linux kernel before 2.6.33 commit
|
||
72f674d203cd230426437cdcf7dd6f681dad8b0d
|
||
will inherit hardware debug registers from parent
|
||
on fork/vfork/clone. Newer Linux kernels create such tasks with
|
||
zeroed debug registers.
|
||
|
||
GDB core assumes the child inherits the watchpoints/hw
|
||
breakpoints of the parent, and will remove them all from the
|
||
forked off process. Copy the debug registers mirrors into the
|
||
new process so that all breakpoints and watchpoints can be
|
||
removed together. The debug registers mirror will become zeroed
|
||
in the end before detaching the forked off process, thus making
|
||
this compatible with older Linux kernels too. */
|
||
|
||
parent_pid = ptid_get_pid (parent->ptid);
|
||
parent_state = x86_debug_reg_state (parent_pid);
|
||
child_state = x86_debug_reg_state (child_pid);
|
||
*child_state = *parent_state;
|
||
}
|
||
|
||
|
||
static void (*super_post_startup_inferior) (struct target_ops *self,
|
||
ptid_t ptid);
|
||
|
||
static void
|
||
x86_linux_child_post_startup_inferior (struct target_ops *self, ptid_t ptid)
|
||
{
|
||
x86_cleanup_dregs ();
|
||
super_post_startup_inferior (self, ptid);
|
||
}
|
||
|
||
#ifdef __x86_64__
|
||
/* Value of CS segment register:
|
||
64bit process: 0x33
|
||
32bit process: 0x23 */
|
||
#define AMD64_LINUX_USER64_CS 0x33
|
||
|
||
/* Value of DS segment register:
|
||
LP64 process: 0x0
|
||
X32 process: 0x2b */
|
||
#define AMD64_LINUX_X32_DS 0x2b
|
||
#endif
|
||
|
||
/* Get Linux/x86 target description from running target. */
|
||
|
||
static const struct target_desc *
|
||
x86_linux_read_description (struct target_ops *ops)
|
||
{
|
||
int tid;
|
||
int is_64bit = 0;
|
||
#ifdef __x86_64__
|
||
int is_x32;
|
||
#endif
|
||
static uint64_t xcr0;
|
||
uint64_t xcr0_features_bits;
|
||
|
||
/* GNU/Linux LWP ID's are process ID's. */
|
||
tid = ptid_get_lwp (inferior_ptid);
|
||
if (tid == 0)
|
||
tid = ptid_get_pid (inferior_ptid); /* Not a threaded program. */
|
||
|
||
#ifdef __x86_64__
|
||
{
|
||
unsigned long cs;
|
||
unsigned long ds;
|
||
|
||
/* 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;
|
||
|
||
/* Get DS register. */
|
||
errno = 0;
|
||
ds = ptrace (PTRACE_PEEKUSER, tid,
|
||
offsetof (struct user_regs_struct, ds), 0);
|
||
if (errno != 0)
|
||
perror_with_name (_("Couldn't get DS register"));
|
||
|
||
is_x32 = ds == AMD64_LINUX_X32_DS;
|
||
|
||
if (sizeof (void *) == 4 && is_64bit && !is_x32)
|
||
error (_("Can't debug 64-bit process with 32-bit GDB"));
|
||
}
|
||
#elif HAVE_PTRACE_GETFPXREGS
|
||
if (have_ptrace_getfpxregs == -1)
|
||
{
|
||
elf_fpxregset_t fpxregs;
|
||
|
||
if (ptrace (PTRACE_GETFPXREGS, tid, 0, (int) &fpxregs) < 0)
|
||
{
|
||
have_ptrace_getfpxregs = 0;
|
||
have_ptrace_getregset = TRIBOOL_FALSE;
|
||
return tdesc_i386_mmx_linux;
|
||
}
|
||
}
|
||
#endif
|
||
|
||
if (have_ptrace_getregset == TRIBOOL_UNKNOWN)
|
||
{
|
||
uint64_t xstateregs[(X86_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, &iov) < 0)
|
||
have_ptrace_getregset = TRIBOOL_FALSE;
|
||
else
|
||
{
|
||
have_ptrace_getregset = TRIBOOL_TRUE;
|
||
|
||
/* 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
|
||
PTRACE_GETREGSET is not available then set xcr0_features_bits to
|
||
zero so that the "no-features" descriptions are returned by the
|
||
switches below. */
|
||
if (have_ptrace_getregset == TRIBOOL_TRUE)
|
||
xcr0_features_bits = xcr0 & X86_XSTATE_ALL_MASK;
|
||
else
|
||
xcr0_features_bits = 0;
|
||
|
||
if (is_64bit)
|
||
{
|
||
#ifdef __x86_64__
|
||
switch (xcr0_features_bits)
|
||
{
|
||
case X86_XSTATE_MPX_AVX512_MASK:
|
||
case X86_XSTATE_AVX512_MASK:
|
||
if (is_x32)
|
||
return tdesc_x32_avx512_linux;
|
||
else
|
||
return tdesc_amd64_avx512_linux;
|
||
case X86_XSTATE_MPX_MASK:
|
||
if (is_x32)
|
||
return tdesc_x32_avx_linux; /* No MPX on x32 using AVX. */
|
||
else
|
||
return tdesc_amd64_mpx_linux;
|
||
case X86_XSTATE_AVX_MASK:
|
||
if (is_x32)
|
||
return tdesc_x32_avx_linux;
|
||
else
|
||
return tdesc_amd64_avx_linux;
|
||
default:
|
||
if (is_x32)
|
||
return tdesc_x32_linux;
|
||
else
|
||
return tdesc_amd64_linux;
|
||
}
|
||
#endif
|
||
}
|
||
else
|
||
{
|
||
switch (xcr0_features_bits)
|
||
{
|
||
case X86_XSTATE_MPX_AVX512_MASK:
|
||
case X86_XSTATE_AVX512_MASK:
|
||
return tdesc_i386_avx512_linux;
|
||
case X86_XSTATE_MPX_MASK:
|
||
return tdesc_i386_mpx_linux;
|
||
case X86_XSTATE_AVX_MASK:
|
||
return tdesc_i386_avx_linux;
|
||
default:
|
||
return tdesc_i386_linux;
|
||
}
|
||
}
|
||
|
||
gdb_assert_not_reached ("failed to return tdesc");
|
||
}
|
||
|
||
|
||
/* Enable branch tracing. */
|
||
|
||
static struct btrace_target_info *
|
||
x86_linux_enable_btrace (struct target_ops *self, ptid_t ptid,
|
||
const struct btrace_config *conf)
|
||
{
|
||
struct btrace_target_info *tinfo;
|
||
struct gdbarch *gdbarch;
|
||
|
||
errno = 0;
|
||
tinfo = linux_enable_btrace (ptid, conf);
|
||
|
||
if (tinfo == NULL)
|
||
error (_("Could not enable branch tracing for %s: %s."),
|
||
target_pid_to_str (ptid), safe_strerror (errno));
|
||
|
||
return tinfo;
|
||
}
|
||
|
||
/* Disable branch tracing. */
|
||
|
||
static void
|
||
x86_linux_disable_btrace (struct target_ops *self,
|
||
struct btrace_target_info *tinfo)
|
||
{
|
||
enum btrace_error errcode = linux_disable_btrace (tinfo);
|
||
|
||
if (errcode != BTRACE_ERR_NONE)
|
||
error (_("Could not disable branch tracing."));
|
||
}
|
||
|
||
/* Teardown branch tracing. */
|
||
|
||
static void
|
||
x86_linux_teardown_btrace (struct target_ops *self,
|
||
struct btrace_target_info *tinfo)
|
||
{
|
||
/* Ignore errors. */
|
||
linux_disable_btrace (tinfo);
|
||
}
|
||
|
||
static enum btrace_error
|
||
x86_linux_read_btrace (struct target_ops *self,
|
||
struct btrace_data *data,
|
||
struct btrace_target_info *btinfo,
|
||
enum btrace_read_type type)
|
||
{
|
||
return linux_read_btrace (data, btinfo, type);
|
||
}
|
||
|
||
/* See to_btrace_conf in target.h. */
|
||
|
||
static const struct btrace_config *
|
||
x86_linux_btrace_conf (struct target_ops *self,
|
||
const struct btrace_target_info *btinfo)
|
||
{
|
||
return linux_btrace_conf (btinfo);
|
||
}
|
||
|
||
|
||
|
||
/* Helper for ps_get_thread_area. Sets BASE_ADDR to a pointer to
|
||
the thread local storage (or its descriptor) and returns PS_OK
|
||
on success. Returns PS_ERR on failure. */
|
||
|
||
ps_err_e
|
||
x86_linux_get_thread_area (pid_t pid, void *addr, unsigned int *base_addr)
|
||
{
|
||
/* NOTE: cagney/2003-08-26: The definition of this buffer is found
|
||
in the kernel header <asm-i386/ldt.h>. It, after padding, is 4 x
|
||
4 byte integers in size: `entry_number', `base_addr', `limit',
|
||
and a bunch of status bits.
|
||
|
||
The values returned by this ptrace call should be part of the
|
||
regcache buffer, and ps_get_thread_area should channel its
|
||
request through the regcache. That way remote targets could
|
||
provide the value using the remote protocol and not this direct
|
||
call.
|
||
|
||
Is this function needed? I'm guessing that the `base' is the
|
||
address of a descriptor that libthread_db uses to find the
|
||
thread local address base that GDB needs. Perhaps that
|
||
descriptor is defined by the ABI. Anyway, given that
|
||
libthread_db calls this function without prompting (gdb
|
||
requesting tls base) I guess it needs info in there anyway. */
|
||
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, pid, addr, &desc) < 0)
|
||
return PS_ERR;
|
||
|
||
*base_addr = desc[1];
|
||
return PS_OK;
|
||
}
|
||
|
||
|
||
/* Create an x86 GNU/Linux target. */
|
||
|
||
struct target_ops *
|
||
x86_linux_create_target (void)
|
||
{
|
||
/* Fill in the generic GNU/Linux methods. */
|
||
struct target_ops *t = linux_target ();
|
||
|
||
/* Initialize the debug register function vectors. */
|
||
x86_use_watchpoints (t);
|
||
x86_dr_low.set_control = x86_linux_dr_set_control;
|
||
x86_dr_low.set_addr = x86_linux_dr_set_addr;
|
||
x86_dr_low.get_addr = x86_linux_dr_get_addr;
|
||
x86_dr_low.get_status = x86_linux_dr_get_status;
|
||
x86_dr_low.get_control = x86_linux_dr_get_control;
|
||
x86_set_debug_register_length (sizeof (void *));
|
||
|
||
/* Override the GNU/Linux inferior startup hook. */
|
||
super_post_startup_inferior = t->to_post_startup_inferior;
|
||
t->to_post_startup_inferior = x86_linux_child_post_startup_inferior;
|
||
|
||
/* Add the description reader. */
|
||
t->to_read_description = x86_linux_read_description;
|
||
|
||
/* Add btrace methods. */
|
||
t->to_supports_btrace = linux_supports_btrace;
|
||
t->to_enable_btrace = x86_linux_enable_btrace;
|
||
t->to_disable_btrace = x86_linux_disable_btrace;
|
||
t->to_teardown_btrace = x86_linux_teardown_btrace;
|
||
t->to_read_btrace = x86_linux_read_btrace;
|
||
t->to_btrace_conf = x86_linux_btrace_conf;
|
||
|
||
return t;
|
||
}
|
||
|
||
/* Add an x86 GNU/Linux target. */
|
||
|
||
void
|
||
x86_linux_add_target (struct target_ops *t)
|
||
{
|
||
linux_nat_add_target (t);
|
||
linux_nat_set_new_thread (t, x86_linux_new_thread);
|
||
linux_nat_set_new_fork (t, x86_linux_new_fork);
|
||
linux_nat_set_forget_process (t, x86_forget_process);
|
||
linux_nat_set_prepare_to_resume (t, x86_linux_prepare_to_resume);
|
||
}
|