binutils-gdb/gdb/amd64-fbsd-tdep.c
John Baldwin f5424cfa7e Support TLS variables on FreeBSD/amd64.
Use the fs_base register to fetch the address of a thread's tcb and
calculate the address of the DTV array.  This value is then passed to
fbsd_get_thread_local_address to compute the final variable address.

Note that fs_base is currently only available via the native target as
core dumps on FreeBSD do not store the value of fs_base.

gdb/ChangeLog:

	* amd64-fbsd-tdep.c (amd64fbsd_get_thread_local_address): New.
	(amd64fbsd_init_abi): Install gdbarch
	"fetch_tls_load_module_address" and "get_thread_local_address"
	methods.
2019-03-12 13:45:48 -07:00

277 lines
7.7 KiB
C
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/* Target-dependent code for FreeBSD/amd64.
Copyright (C) 2003-2019 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 "arch-utils.h"
#include "frame.h"
#include "gdbcore.h"
#include "regcache.h"
#include "osabi.h"
#include "regset.h"
#include "i386-fbsd-tdep.h"
#include "common/x86-xstate.h"
#include "amd64-tdep.h"
#include "fbsd-tdep.h"
#include "solib-svr4.h"
/* Support for signal handlers. */
/* Return whether THIS_FRAME corresponds to a FreeBSD sigtramp
routine. */
static const gdb_byte amd64fbsd_sigtramp_code[] =
{
0x48, 0x8d, 0x7c, 0x24, 0x10, /* lea SIGF_UC(%rsp),%rdi */
0x6a, 0x00, /* pushq $0 */
0x48, 0xc7, 0xc0, 0xa1, 0x01, 0x00, 0x00,
/* movq $SYS_sigreturn,%rax */
0x0f, 0x05 /* syscall */
};
static int
amd64fbsd_sigtramp_p (struct frame_info *this_frame)
{
CORE_ADDR pc = get_frame_pc (this_frame);
gdb_byte buf[sizeof amd64fbsd_sigtramp_code];
if (!safe_frame_unwind_memory (this_frame, pc, buf, sizeof buf))
return 0;
if (memcmp (buf, amd64fbsd_sigtramp_code, sizeof amd64fbsd_sigtramp_code)
!= 0)
return 0;
return 1;
}
/* Assuming THIS_FRAME is for a BSD sigtramp routine, return the
address of the associated sigcontext structure. */
static CORE_ADDR
amd64fbsd_sigcontext_addr (struct frame_info *this_frame)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
CORE_ADDR sp;
gdb_byte buf[8];
/* The `struct sigcontext' (which really is an `ucontext_t' on
FreeBSD/amd64) lives at a fixed offset in the signal frame. See
<machine/sigframe.h>. */
get_frame_register (this_frame, AMD64_RSP_REGNUM, buf);
sp = extract_unsigned_integer (buf, 8, byte_order);
return sp + 16;
}
/* FreeBSD 5.1-RELEASE or later. */
/* Mapping between the general-purpose registers in `struct reg'
format and GDB's register cache layout.
Note that some registers are 32-bit, but since we're little-endian
we get away with that. */
/* From <machine/reg.h>. */
static int amd64fbsd_r_reg_offset[] =
{
14 * 8, /* %rax */
11 * 8, /* %rbx */
13 * 8, /* %rcx */
12 * 8, /* %rdx */
9 * 8, /* %rsi */
8 * 8, /* %rdi */
10 * 8, /* %rbp */
20 * 8, /* %rsp */
7 * 8, /* %r8 ... */
6 * 8,
5 * 8,
4 * 8,
3 * 8,
2 * 8,
1 * 8,
0 * 8, /* ... %r15 */
17 * 8, /* %rip */
19 * 8, /* %eflags */
18 * 8, /* %cs */
21 * 8, /* %ss */
-1, /* %ds */
-1, /* %es */
-1, /* %fs */
-1 /* %gs */
};
/* Location of the signal trampoline. */
CORE_ADDR amd64fbsd_sigtramp_start_addr;
CORE_ADDR amd64fbsd_sigtramp_end_addr;
/* From <machine/signal.h>. */
int amd64fbsd_sc_reg_offset[] =
{
24 + 6 * 8, /* %rax */
24 + 7 * 8, /* %rbx */
24 + 3 * 8, /* %rcx */
24 + 2 * 8, /* %rdx */
24 + 1 * 8, /* %rsi */
24 + 0 * 8, /* %rdi */
24 + 8 * 8, /* %rbp */
24 + 22 * 8, /* %rsp */
24 + 4 * 8, /* %r8 ... */
24 + 5 * 8,
24 + 9 * 8,
24 + 10 * 8,
24 + 11 * 8,
24 + 12 * 8,
24 + 13 * 8,
24 + 14 * 8, /* ... %r15 */
24 + 19 * 8, /* %rip */
24 + 21 * 8, /* %eflags */
24 + 20 * 8, /* %cs */
24 + 23 * 8, /* %ss */
-1, /* %ds */
-1, /* %es */
-1, /* %fs */
-1 /* %gs */
};
/* Implement the core_read_description gdbarch method. */
static const struct target_desc *
amd64fbsd_core_read_description (struct gdbarch *gdbarch,
struct target_ops *target,
bfd *abfd)
{
return amd64_target_description (i386fbsd_core_read_xcr0 (abfd), true);
}
/* Similar to amd64_supply_fpregset, but use XSAVE extended state. */
static void
amd64fbsd_supply_xstateregset (const struct regset *regset,
struct regcache *regcache, int regnum,
const void *xstateregs, size_t len)
{
amd64_supply_xsave (regcache, regnum, xstateregs);
}
/* Similar to amd64_collect_fpregset, but use XSAVE extended state. */
static void
amd64fbsd_collect_xstateregset (const struct regset *regset,
const struct regcache *regcache,
int regnum, void *xstateregs, size_t len)
{
amd64_collect_xsave (regcache, regnum, xstateregs, 1);
}
static const struct regset amd64fbsd_xstateregset =
{
NULL,
amd64fbsd_supply_xstateregset,
amd64fbsd_collect_xstateregset
};
/* Iterate over core file register note sections. */
static void
amd64fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
iterate_over_regset_sections_cb *cb,
void *cb_data,
const struct regcache *regcache)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
cb (".reg", tdep->sizeof_gregset, tdep->sizeof_gregset, &i386_gregset, NULL,
cb_data);
cb (".reg2", tdep->sizeof_fpregset, tdep->sizeof_fpregset, &amd64_fpregset,
NULL, cb_data);
cb (".reg-xstate", X86_XSTATE_SIZE (tdep->xcr0), X86_XSTATE_SIZE (tdep->xcr0),
&amd64fbsd_xstateregset, "XSAVE extended state", cb_data);
}
/* Implement the get_thread_local_address gdbarch method. */
static CORE_ADDR
amd64fbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
CORE_ADDR lm_addr, CORE_ADDR offset)
{
struct regcache *regcache;
regcache = get_thread_arch_regcache (ptid, gdbarch);
target_fetch_registers (regcache, AMD64_FSBASE_REGNUM);
ULONGEST fsbase;
if (regcache->cooked_read (AMD64_FSBASE_REGNUM, &fsbase) != REG_VALID)
error (_("Unable to fetch %%fsbase"));
CORE_ADDR dtv_addr = fsbase + gdbarch_ptr_bit (gdbarch) / 8;
return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
}
static void
amd64fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* Generic FreeBSD support. */
fbsd_init_abi (info, gdbarch);
/* Obviously FreeBSD is BSD-based. */
i386bsd_init_abi (info, gdbarch);
tdep->gregset_reg_offset = amd64fbsd_r_reg_offset;
tdep->gregset_num_regs = ARRAY_SIZE (amd64fbsd_r_reg_offset);
tdep->sizeof_gregset = 22 * 8;
amd64_init_abi (info, gdbarch,
amd64_target_description (X86_XSTATE_SSE_MASK, true));
tdep->sigtramp_p = amd64fbsd_sigtramp_p;
tdep->sigtramp_start = amd64fbsd_sigtramp_start_addr;
tdep->sigtramp_end = amd64fbsd_sigtramp_end_addr;
tdep->sigcontext_addr = amd64fbsd_sigcontext_addr;
tdep->sc_reg_offset = amd64fbsd_sc_reg_offset;
tdep->sc_num_regs = ARRAY_SIZE (amd64fbsd_sc_reg_offset);
tdep->xsave_xcr0_offset = I386_FBSD_XSAVE_XCR0_OFFSET;
/* Iterate over core file register note sections. */
set_gdbarch_iterate_over_regset_sections
(gdbarch, amd64fbsd_iterate_over_regset_sections);
set_gdbarch_core_read_description (gdbarch,
amd64fbsd_core_read_description);
/* FreeBSD uses SVR4-style shared libraries. */
set_solib_svr4_fetch_link_map_offsets
(gdbarch, svr4_lp64_fetch_link_map_offsets);
set_gdbarch_fetch_tls_load_module_address (gdbarch,
svr4_fetch_objfile_link_map);
set_gdbarch_get_thread_local_address (gdbarch,
amd64fbsd_get_thread_local_address);
}
void
_initialize_amd64fbsd_tdep (void)
{
gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
GDB_OSABI_FREEBSD, amd64fbsd_init_abi);
}