9cf12d57c5
Building an x32 gdb trips on a static assertion:
In file included from .../src/gdb/common/common-defs.h:71:0,
from .../src/gdb/nat/amd64-linux-siginfo.c:21:
.../src/gdb/common/gdb_assert.h:26:66: error: size of array ‘never_defined_just_used_for_checking’ is negative
extern int never_defined_just_used_for_checking[(expr) ? 1 : -1]
^
.../src/gdb/nat/amd64-linux-siginfo.c:113:1: note: in expansion of macro ‘gdb_static_assert’
gdb_static_assert (sizeof (nat_siginfo_t) == sizeof (siginfo_t));
^
The problem is that the way nat_siginfo_t is defined, it can only
match the host's siginfo_t object when gdb is built as a 64-bit
program.
Several bits of nat_siginfo_t are off:
- nat_siginfo_t's _pad field's definition is:
int _pad[((128 / sizeof (int)) - 4)];
while /usr/include/bits/siginfo.h has:
# define __SI_MAX_SIZE 128
# if __WORDSIZE == 64
# define __SI_PAD_SIZE ((__SI_MAX_SIZE / sizeof (int)) - 4)
# else
# define __SI_PAD_SIZE ((__SI_MAX_SIZE / sizeof (int)) - 3)
# endif
and __WORDSIZE == 32 for x32. This is what causes the size of
nat_siginfo_t to be wrong and the assertion to fail.
- the nat_clock_t type is incorrect for 64-bit. We have this:
/* For native 64-bit, clock_t in _sigchld is 64bit aligned at 4 bytes. */
typedef long __attribute__ ((__aligned__ (4))) nat_clock_t;
however, /usr/include/bits/siginfo.h has:
# if defined __x86_64__ && __WORDSIZE == 32
/* si_utime and si_stime must be 4 byte aligned for x32 to match the
kernel. We align siginfo_t to 8 bytes so that si_utime and si_stime
are actually aligned to 8 bytes since their offsets are multiple of
8 bytes. */
typedef __clock_t __attribute__ ((__aligned__ (4))) __sigchld_clock_t;
# define __SI_ALIGNMENT __attribute__ ((__aligned__ (8)))
# else
typedef __clock_t __sigchld_clock_t;
# define __SI_ALIGNMENT
# endif
So we're currently forcing 4-byte alignment on clock_t, when it
should only be so for x32, not 64-bit.
The fix:
- Leaves nat_siginfo_t strictly for the 64-bit ABI.
- Adds a new typedef for the siginfo type that ptrace uses
(ptrace_siginfo_t). An x32 gdb always gets/sets an x32 siginfo_t
type with PTRACE_GETSIGINFO/PTRACE_SETSIGINFO.
- Uses this new ptrace_siginfo_t type instead of nat_siginfo_t as the
intermediate conversion type.
gdb/ChangeLog:
2016-07-26 Pedro Alves <palves@redhat.com>
* amd64-linux-nat.c (amd64_linux_siginfo_fixup): Rename 'native'
parameter to 'ptrace'.
* nat/amd64-linux-siginfo.c (GDB_SI_SIZE): New define.
(nat_uptr_t): New an unsigned long.
(nat_clock_t): Remove attribute __aligned__.
(struct nat_timeval): Delete.
(nat_siginfo_t): Remove attribute __aligned__.
(ptrace_siginfo_t): Define.
(compat_siginfo_from_siginfo, siginfo_from_compat_siginfo)
(compat_x32_siginfo_from_siginfo)
(siginfo_from_compat_x32_siginfo): Make 'from' parameter const.
Convert through a ptrace_siginfo_t instead of a nat_siginfo_t.
Remove casts.
(amd64_linux_siginfo_fixup_common): Rename 'native' parameter to
'ptrace'. Remove static assertions.
(top level): New static assertions.
gdb/gdbserver/ChangeLog:
2016-07-26 Pedro Alves <palves@redhat.com>
* linux-x86-low.c (x86_siginfo_fixup): Rename 'native' parameter
to 'ptrace'.
376 lines
11 KiB
C
376 lines
11 KiB
C
/* Native-dependent code for GNU/Linux x86-64.
|
||
|
||
Copyright (C) 2001-2016 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 <http://www.gnu.org/licenses/>. */
|
||
|
||
#include "defs.h"
|
||
#include "inferior.h"
|
||
#include "regcache.h"
|
||
#include "elf/common.h"
|
||
#include <sys/uio.h>
|
||
#include "nat/gdb_ptrace.h"
|
||
#include <asm/prctl.h>
|
||
#include <sys/reg.h>
|
||
#include "gregset.h"
|
||
#include "gdb_proc_service.h"
|
||
|
||
#include "amd64-nat.h"
|
||
#include "linux-nat.h"
|
||
#include "amd64-tdep.h"
|
||
#include "amd64-linux-tdep.h"
|
||
#include "i386-linux-tdep.h"
|
||
#include "x86-xstate.h"
|
||
|
||
#include "x86-linux-nat.h"
|
||
#include "nat/linux-ptrace.h"
|
||
#include "nat/amd64-linux-siginfo.h"
|
||
|
||
/* 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 <sys/reg.h> 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,
|
||
-1, -1, -1, -1, /* MPX registers BND0 ... BND3. */
|
||
-1, -1, /* MPX registers BNDCFGU, BNDSTATUS. */
|
||
-1, -1, -1, -1, -1, -1, -1, -1, /* k0 ... k7 (AVX512) */
|
||
-1, -1, -1, -1, -1, -1, -1, -1, /* zmm0 ... zmm7 (AVX512) */
|
||
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 = ptid_get_lwp (inferior_ptid);
|
||
if (tid == 0)
|
||
tid = ptid_get_pid (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 == TRIBOOL_TRUE)
|
||
{
|
||
char xstateregs[X86_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 = ptid_get_lwp (inferior_ptid);
|
||
if (tid == 0)
|
||
tid = ptid_get_pid (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 == TRIBOOL_TRUE)
|
||
{
|
||
char xstateregs[X86_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"));
|
||
}
|
||
}
|
||
}
|
||
|
||
|
||
/* 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_bfd_arch_info (target_gdbarch ())->bits_per_word == 32)
|
||
{
|
||
unsigned int base_addr;
|
||
ps_err_e result;
|
||
|
||
result = x86_linux_get_thread_area (lwpid, (void *) (long) idx,
|
||
&base_addr);
|
||
if (result == PS_OK)
|
||
{
|
||
/* Extend the value to 64 bits. Here it's assumed that
|
||
a "long" and a "void *" are the same. */
|
||
(*base) = (void *) (long) base_addr;
|
||
}
|
||
return result;
|
||
}
|
||
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:
|
||
#ifdef HAVE_STRUCT_USER_REGS_STRUCT_FS_BASE
|
||
{
|
||
/* PTRACE_ARCH_PRCTL is obsolete since 2.6.25, where the
|
||
fs_base and gs_base fields of user_regs_struct can be
|
||
used directly. */
|
||
unsigned long fs;
|
||
errno = 0;
|
||
fs = ptrace (PTRACE_PEEKUSER, lwpid,
|
||
offsetof (struct user_regs_struct, fs_base), 0);
|
||
if (errno == 0)
|
||
{
|
||
*base = (void *) fs;
|
||
return PS_OK;
|
||
}
|
||
}
|
||
#endif
|
||
if (ptrace (PTRACE_ARCH_PRCTL, lwpid, base, ARCH_GET_FS) == 0)
|
||
return PS_OK;
|
||
break;
|
||
case GS:
|
||
#ifdef HAVE_STRUCT_USER_REGS_STRUCT_GS_BASE
|
||
{
|
||
unsigned long gs;
|
||
errno = 0;
|
||
gs = ptrace (PTRACE_PEEKUSER, lwpid,
|
||
offsetof (struct user_regs_struct, gs_base), 0);
|
||
if (errno == 0)
|
||
{
|
||
*base = (void *) gs;
|
||
return PS_OK;
|
||
}
|
||
}
|
||
#endif
|
||
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. */
|
||
}
|
||
|
||
|
||
/* Convert a ptrace/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 PTRACE. If DIRECTION is 0, copy from PTRACE to
|
||
INF. */
|
||
|
||
static int
|
||
amd64_linux_siginfo_fixup (siginfo_t *ptrace, gdb_byte *inf, int direction)
|
||
{
|
||
struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
|
||
|
||
/* Is the inferior 32-bit? If so, then do fixup the siginfo
|
||
object. */
|
||
if (gdbarch_bfd_arch_info (gdbarch)->bits_per_word == 32)
|
||
return amd64_linux_siginfo_fixup_common (ptrace, inf, direction,
|
||
FIXUP_32);
|
||
/* No fixup for native x32 GDB. */
|
||
else if (gdbarch_addr_bit (gdbarch) == 32 && sizeof (void *) == 8)
|
||
return amd64_linux_siginfo_fixup_common (ptrace, inf, direction,
|
||
FIXUP_X32);
|
||
else
|
||
return 0;
|
||
}
|
||
|
||
/* 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);
|
||
|
||
/* Create a generic x86 GNU/Linux target. */
|
||
t = x86_linux_create_target ();
|
||
|
||
/* Add our register access methods. */
|
||
t->to_fetch_registers = amd64_linux_fetch_inferior_registers;
|
||
t->to_store_registers = amd64_linux_store_inferior_registers;
|
||
|
||
/* Add the target. */
|
||
x86_linux_add_target (t);
|
||
|
||
/* Add our siginfo layout converter. */
|
||
linux_nat_set_siginfo_fixup (t, amd64_linux_siginfo_fixup);
|
||
}
|