binutils-gdb/gdb/mips-fbsd-tdep.c
John Baldwin 7755ddb77d Look for FIR in the last FreeBSD/mips floating-point register.
FreeBSD/mips kernels were recently changed to include the floating
point implementation revision register in the floating point register
set exported in process cores and via ptrace() (r318067).  This change
will first ship in FreeBSD 12.0 when it is eventually released.  The
space used to hold FIR was previously reserved in 'struct fpreg' as a
zero-filled dummy for padding, so 'struct fpreg' has not changed in
size.  Since FIR should be non-zero on all MIPS processors supported
by FreeBSD, ignore a value of 0 from 'struct fpreg' and only report
non-zero values as a valid FIR register.

gdb/ChangeLog:

	* mips-fbsd-nat.c (getfpregs_supplies): Return true for FIR.
	* mips-fbsd-tdep.c (mips_fbsd_supply_fpregs): Split supply of FSR
	out of loop and add supply of FIR.
	(mips_fbsd_collect_fpregs): Split collect of FSR out of loop and
	add collect of FIR.
2017-08-29 15:04:09 -07:00

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/* Target-dependent code for FreeBSD/mips.
Copyright (C) 2017 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 "osabi.h"
#include "regset.h"
#include "trad-frame.h"
#include "tramp-frame.h"
#include "fbsd-tdep.h"
#include "mips-tdep.h"
#include "mips-fbsd-tdep.h"
#include "solib-svr4.h"
/* Core file support. */
/* Number of registers in `struct reg' from <machine/reg.h>. The
first 38 follow the standard MIPS layout. The 39th holds
IC_INT_REG on RM7K and RM9K processors. The 40th is a dummy for
padding. */
#define MIPS_FBSD_NUM_GREGS 40
/* Number of registers in `struct fpreg' from <machine/reg.h>. The
first 32 hold floating point registers. 33 holds the FSR. The
34th holds FIR on FreeBSD 12.0 and newer kernels. On older kernels
it was a zero-filled dummy for padding. */
#define MIPS_FBSD_NUM_FPREGS 34
/* Supply a single register. The register size might not match, so use
regcache->raw_supply_integer (). */
static void
mips_fbsd_supply_reg (struct regcache *regcache, int regnum, const void *addr,
size_t len)
{
regcache->raw_supply_integer (regnum, (const gdb_byte *) addr, len, true);
}
/* Collect a single register. The register size might not match, so use
regcache->raw_collect_integer (). */
static void
mips_fbsd_collect_reg (const struct regcache *regcache, int regnum, void *addr,
size_t len)
{
regcache->raw_collect_integer (regnum, (gdb_byte *) addr, len, true);
}
/* Supply the floating-point registers stored in FPREGS to REGCACHE.
Each floating-point register in FPREGS is REGSIZE bytes in
length. */
void
mips_fbsd_supply_fpregs (struct regcache *regcache, int regnum,
const void *fpregs, size_t regsize)
{
struct gdbarch *gdbarch = get_regcache_arch (regcache);
const gdb_byte *regs = (const gdb_byte *) fpregs;
int i, fp0num;
fp0num = mips_regnum (gdbarch)->fp0;
for (i = 0; i <= 32; i++)
if (regnum == fp0num + i || regnum == -1)
mips_fbsd_supply_reg (regcache, fp0num + i,
regs + i * regsize, regsize);
if (regnum == mips_regnum (gdbarch)->fp_control_status || regnum == -1)
mips_fbsd_supply_reg (regcache, mips_regnum (gdbarch)->fp_control_status,
regs + 32 * regsize, regsize);
if ((regnum == mips_regnum (gdbarch)->fp_implementation_revision
|| regnum == -1)
&& extract_unsigned_integer (regs + 33 * regsize, regsize,
gdbarch_byte_order (gdbarch)) != 0)
mips_fbsd_supply_reg (regcache,
mips_regnum (gdbarch)->fp_implementation_revision,
regs + 33 * regsize, regsize);
}
/* Supply the general-purpose registers stored in GREGS to REGCACHE.
Each general-purpose register in GREGS is REGSIZE bytes in
length. */
void
mips_fbsd_supply_gregs (struct regcache *regcache, int regnum,
const void *gregs, size_t regsize)
{
struct gdbarch *gdbarch = get_regcache_arch (regcache);
const gdb_byte *regs = (const gdb_byte *) gregs;
int i;
for (i = 0; i <= mips_regnum (gdbarch)->pc; i++)
if (regnum == i || regnum == -1)
mips_fbsd_supply_reg (regcache, i, regs + i * regsize, regsize);
}
/* Collect the floating-point registers from REGCACHE and store them
in FPREGS. Each floating-point register in FPREGS is REGSIZE bytes
in length. */
void
mips_fbsd_collect_fpregs (const struct regcache *regcache, int regnum,
void *fpregs, size_t regsize)
{
struct gdbarch *gdbarch = get_regcache_arch (regcache);
gdb_byte *regs = (gdb_byte *) fpregs;
int i, fp0num;
fp0num = mips_regnum (gdbarch)->fp0;
for (i = 0; i < 32; i++)
if (regnum == fp0num + i || regnum == -1)
mips_fbsd_collect_reg (regcache, fp0num + i,
regs + i * regsize, regsize);
if (regnum == mips_regnum (gdbarch)->fp_control_status || regnum == -1)
mips_fbsd_collect_reg (regcache, mips_regnum (gdbarch)->fp_control_status,
regs + 32 * regsize, regsize);
if (regnum == mips_regnum (gdbarch)->fp_implementation_revision
|| regnum == -1)
mips_fbsd_collect_reg (regcache,
mips_regnum (gdbarch)->fp_implementation_revision,
regs + 33 * regsize, regsize);
}
/* Collect the general-purpose registers from REGCACHE and store them
in GREGS. Each general-purpose register in GREGS is REGSIZE bytes
in length. */
void
mips_fbsd_collect_gregs (const struct regcache *regcache, int regnum,
void *gregs, size_t regsize)
{
struct gdbarch *gdbarch = get_regcache_arch (regcache);
gdb_byte *regs = (gdb_byte *) gregs;
int i;
for (i = 0; i <= mips_regnum (gdbarch)->pc; i++)
if (regnum == i || regnum == -1)
mips_fbsd_collect_reg (regcache, i, regs + i * regsize, regsize);
}
/* Supply register REGNUM from the buffer specified by FPREGS and LEN
in the floating-point register set REGSET to register cache
REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
static void
mips_fbsd_supply_fpregset (const struct regset *regset,
struct regcache *regcache,
int regnum, const void *fpregs, size_t len)
{
size_t regsize = mips_abi_regsize (get_regcache_arch (regcache));
gdb_assert (len >= MIPS_FBSD_NUM_FPREGS * regsize);
mips_fbsd_supply_fpregs (regcache, regnum, fpregs, regsize);
}
/* Collect register REGNUM from the register cache REGCACHE and store
it in the buffer specified by FPREGS and LEN in the floating-point
register set REGSET. If REGNUM is -1, do this for all registers in
REGSET. */
static void
mips_fbsd_collect_fpregset (const struct regset *regset,
const struct regcache *regcache,
int regnum, void *fpregs, size_t len)
{
size_t regsize = mips_abi_regsize (get_regcache_arch (regcache));
gdb_assert (len >= MIPS_FBSD_NUM_FPREGS * regsize);
mips_fbsd_collect_fpregs (regcache, regnum, fpregs, regsize);
}
/* Supply register REGNUM from the buffer specified by GREGS and LEN
in the general-purpose register set REGSET to register cache
REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */
static void
mips_fbsd_supply_gregset (const struct regset *regset,
struct regcache *regcache, int regnum,
const void *gregs, size_t len)
{
size_t regsize = mips_abi_regsize (get_regcache_arch (regcache));
gdb_assert (len >= MIPS_FBSD_NUM_GREGS * regsize);
mips_fbsd_supply_gregs (regcache, regnum, gregs, regsize);
}
/* Collect register REGNUM from the register cache REGCACHE and store
it in the buffer specified by GREGS and LEN in the general-purpose
register set REGSET. If REGNUM is -1, do this for all registers in
REGSET. */
static void
mips_fbsd_collect_gregset (const struct regset *regset,
const struct regcache *regcache,
int regnum, void *gregs, size_t len)
{
size_t regsize = mips_abi_regsize (get_regcache_arch (regcache));
gdb_assert (len >= MIPS_FBSD_NUM_GREGS * regsize);
mips_fbsd_collect_gregs (regcache, regnum, gregs, regsize);
}
/* FreeBSD/mips register sets. */
static const struct regset mips_fbsd_gregset =
{
NULL,
mips_fbsd_supply_gregset,
mips_fbsd_collect_gregset,
};
static const struct regset mips_fbsd_fpregset =
{
NULL,
mips_fbsd_supply_fpregset,
mips_fbsd_collect_fpregset,
};
/* Iterate over core file register note sections. */
static void
mips_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
iterate_over_regset_sections_cb *cb,
void *cb_data,
const struct regcache *regcache)
{
size_t regsize = mips_abi_regsize (gdbarch);
cb (".reg", MIPS_FBSD_NUM_GREGS * regsize, &mips_fbsd_gregset,
NULL, cb_data);
cb (".reg2", MIPS_FBSD_NUM_FPREGS * regsize, &mips_fbsd_fpregset,
NULL, cb_data);
}
/* Signal trampoline support. */
#define FBSD_SYS_sigreturn 417
#define MIPS_INST_LI_V0_SIGRETURN 0x24020000 + FBSD_SYS_sigreturn
#define MIPS_INST_SYSCALL 0x0000000c
#define MIPS_INST_BREAK 0x0000000d
#define O32_SIGFRAME_UCONTEXT_OFFSET (16)
#define O32_SIGSET_T_SIZE (16)
#define O32_UCONTEXT_ONSTACK (O32_SIGSET_T_SIZE)
#define O32_UCONTEXT_PC (O32_UCONTEXT_ONSTACK + 4)
#define O32_UCONTEXT_REGS (O32_UCONTEXT_PC + 4)
#define O32_UCONTEXT_SR (O32_UCONTEXT_REGS + 4 * 32)
#define O32_UCONTEXT_LO (O32_UCONTEXT_SR + 4)
#define O32_UCONTEXT_HI (O32_UCONTEXT_LO + 4)
#define O32_UCONTEXT_FPUSED (O32_UCONTEXT_HI + 4)
#define O32_UCONTEXT_FPREGS (O32_UCONTEXT_FPUSED + 4)
#define O32_UCONTEXT_REG_SIZE 4
static void
mips_fbsd_sigframe_init (const struct tramp_frame *self,
struct frame_info *this_frame,
struct trad_frame_cache *cache,
CORE_ADDR func)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
CORE_ADDR sp, ucontext_addr, addr;
int regnum;
gdb_byte buf[4];
/* We find the appropriate instance of `ucontext_t' at a
fixed offset in the signal frame. */
sp = get_frame_register_signed (this_frame,
MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
ucontext_addr = sp + O32_SIGFRAME_UCONTEXT_OFFSET;
/* PC. */
regnum = mips_regnum (gdbarch)->pc;
trad_frame_set_reg_addr (cache,
regnum + gdbarch_num_regs (gdbarch),
ucontext_addr + O32_UCONTEXT_PC);
/* GPRs. */
for (regnum = MIPS_ZERO_REGNUM, addr = ucontext_addr + O32_UCONTEXT_REGS;
regnum <= MIPS_RA_REGNUM; regnum++, addr += O32_UCONTEXT_REG_SIZE)
trad_frame_set_reg_addr (cache,
regnum + gdbarch_num_regs (gdbarch),
addr);
regnum = MIPS_PS_REGNUM;
trad_frame_set_reg_addr (cache,
regnum + gdbarch_num_regs (gdbarch),
ucontext_addr + O32_UCONTEXT_SR);
/* HI and LO. */
regnum = mips_regnum (gdbarch)->lo;
trad_frame_set_reg_addr (cache,
regnum + gdbarch_num_regs (gdbarch),
ucontext_addr + O32_UCONTEXT_LO);
regnum = mips_regnum (gdbarch)->hi;
trad_frame_set_reg_addr (cache,
regnum + gdbarch_num_regs (gdbarch),
ucontext_addr + O32_UCONTEXT_HI);
if (target_read_memory (ucontext_addr + O32_UCONTEXT_FPUSED, buf, 4) == 0
&& extract_unsigned_integer (buf, 4, byte_order) != 0)
{
for (regnum = 0, addr = ucontext_addr + O32_UCONTEXT_FPREGS;
regnum < 32; regnum++, addr += O32_UCONTEXT_REG_SIZE)
trad_frame_set_reg_addr (cache,
regnum + gdbarch_fp0_regnum (gdbarch),
addr);
trad_frame_set_reg_addr (cache, mips_regnum (gdbarch)->fp_control_status,
addr);
}
trad_frame_set_id (cache, frame_id_build (sp, func));
}
#define MIPS_INST_ADDIU_A0_SP_O32 (0x27a40000 \
+ O32_SIGFRAME_UCONTEXT_OFFSET)
static const struct tramp_frame mips_fbsd_sigframe =
{
SIGTRAMP_FRAME,
MIPS_INSN32_SIZE,
{
{ MIPS_INST_ADDIU_A0_SP_O32, -1 }, /* addiu a0, sp, SIGF_UC */
{ MIPS_INST_LI_V0_SIGRETURN, -1 }, /* li v0, SYS_sigreturn */
{ MIPS_INST_SYSCALL, -1 }, /* syscall */
{ MIPS_INST_BREAK, -1 }, /* break */
{ TRAMP_SENTINEL_INSN, -1 }
},
mips_fbsd_sigframe_init
};
#define N64_SIGFRAME_UCONTEXT_OFFSET (32)
#define N64_SIGSET_T_SIZE (16)
#define N64_UCONTEXT_ONSTACK (N64_SIGSET_T_SIZE)
#define N64_UCONTEXT_PC (N64_UCONTEXT_ONSTACK + 8)
#define N64_UCONTEXT_REGS (N64_UCONTEXT_PC + 8)
#define N64_UCONTEXT_SR (N64_UCONTEXT_REGS + 8 * 32)
#define N64_UCONTEXT_LO (N64_UCONTEXT_SR + 8)
#define N64_UCONTEXT_HI (N64_UCONTEXT_LO + 8)
#define N64_UCONTEXT_FPUSED (N64_UCONTEXT_HI + 8)
#define N64_UCONTEXT_FPREGS (N64_UCONTEXT_FPUSED + 8)
#define N64_UCONTEXT_REG_SIZE 8
static void
mips64_fbsd_sigframe_init (const struct tramp_frame *self,
struct frame_info *this_frame,
struct trad_frame_cache *cache,
CORE_ADDR func)
{
struct gdbarch *gdbarch = get_frame_arch (this_frame);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
CORE_ADDR sp, ucontext_addr, addr;
int regnum;
gdb_byte buf[4];
/* We find the appropriate instance of `ucontext_t' at a
fixed offset in the signal frame. */
sp = get_frame_register_signed (this_frame,
MIPS_SP_REGNUM + gdbarch_num_regs (gdbarch));
ucontext_addr = sp + N64_SIGFRAME_UCONTEXT_OFFSET;
/* PC. */
regnum = mips_regnum (gdbarch)->pc;
trad_frame_set_reg_addr (cache,
regnum + gdbarch_num_regs (gdbarch),
ucontext_addr + N64_UCONTEXT_PC);
/* GPRs. */
for (regnum = MIPS_ZERO_REGNUM, addr = ucontext_addr + N64_UCONTEXT_REGS;
regnum <= MIPS_RA_REGNUM; regnum++, addr += N64_UCONTEXT_REG_SIZE)
trad_frame_set_reg_addr (cache,
regnum + gdbarch_num_regs (gdbarch),
addr);
regnum = MIPS_PS_REGNUM;
trad_frame_set_reg_addr (cache,
regnum + gdbarch_num_regs (gdbarch),
ucontext_addr + N64_UCONTEXT_SR);
/* HI and LO. */
regnum = mips_regnum (gdbarch)->lo;
trad_frame_set_reg_addr (cache,
regnum + gdbarch_num_regs (gdbarch),
ucontext_addr + N64_UCONTEXT_LO);
regnum = mips_regnum (gdbarch)->hi;
trad_frame_set_reg_addr (cache,
regnum + gdbarch_num_regs (gdbarch),
ucontext_addr + N64_UCONTEXT_HI);
if (target_read_memory (ucontext_addr + N64_UCONTEXT_FPUSED, buf, 4) == 0
&& extract_unsigned_integer (buf, 4, byte_order) != 0)
{
for (regnum = 0, addr = ucontext_addr + N64_UCONTEXT_FPREGS;
regnum < 32; regnum++, addr += N64_UCONTEXT_REG_SIZE)
trad_frame_set_reg_addr (cache,
regnum + gdbarch_fp0_regnum (gdbarch),
addr);
trad_frame_set_reg_addr (cache, mips_regnum (gdbarch)->fp_control_status,
addr);
}
trad_frame_set_id (cache, frame_id_build (sp, func));
}
#define MIPS_INST_DADDIU_A0_SP_N64 (0x67a40000 \
+ N64_SIGFRAME_UCONTEXT_OFFSET)
static const struct tramp_frame mips64_fbsd_sigframe =
{
SIGTRAMP_FRAME,
MIPS_INSN32_SIZE,
{
{ MIPS_INST_DADDIU_A0_SP_N64, -1 }, /* daddiu a0, sp, SIGF_UC */
{ MIPS_INST_LI_V0_SIGRETURN, -1 }, /* li v0, SYS_sigreturn */
{ MIPS_INST_SYSCALL, -1 }, /* syscall */
{ MIPS_INST_BREAK, -1 }, /* break */
{ TRAMP_SENTINEL_INSN, -1 }
},
mips64_fbsd_sigframe_init
};
/* Shared library support. */
/* FreeBSD/mips uses a slightly different `struct link_map' than the
other FreeBSD platforms as it includes an additional `l_off'
member. */
static struct link_map_offsets *
mips_fbsd_ilp32_fetch_link_map_offsets (void)
{
static struct link_map_offsets lmo;
static struct link_map_offsets *lmp = NULL;
if (lmp == NULL)
{
lmp = &lmo;
lmo.r_version_offset = 0;
lmo.r_version_size = 4;
lmo.r_map_offset = 4;
lmo.r_brk_offset = 8;
lmo.r_ldsomap_offset = -1;
lmo.link_map_size = 24;
lmo.l_addr_offset = 0;
lmo.l_name_offset = 8;
lmo.l_ld_offset = 12;
lmo.l_next_offset = 16;
lmo.l_prev_offset = 20;
}
return lmp;
}
static struct link_map_offsets *
mips_fbsd_lp64_fetch_link_map_offsets (void)
{
static struct link_map_offsets lmo;
static struct link_map_offsets *lmp = NULL;
if (lmp == NULL)
{
lmp = &lmo;
lmo.r_version_offset = 0;
lmo.r_version_size = 4;
lmo.r_map_offset = 8;
lmo.r_brk_offset = 16;
lmo.r_ldsomap_offset = -1;
lmo.link_map_size = 48;
lmo.l_addr_offset = 0;
lmo.l_name_offset = 16;
lmo.l_ld_offset = 24;
lmo.l_next_offset = 32;
lmo.l_prev_offset = 40;
}
return lmp;
}
static void
mips_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
enum mips_abi abi = mips_abi (gdbarch);
/* Generic FreeBSD support. */
fbsd_init_abi (info, gdbarch);
set_gdbarch_software_single_step (gdbarch, mips_software_single_step);
switch (abi)
{
case MIPS_ABI_O32:
tramp_frame_prepend_unwinder (gdbarch, &mips_fbsd_sigframe);
break;
case MIPS_ABI_N32:
break;
case MIPS_ABI_N64:
tramp_frame_prepend_unwinder (gdbarch, &mips64_fbsd_sigframe);
break;
}
set_gdbarch_iterate_over_regset_sections
(gdbarch, mips_fbsd_iterate_over_regset_sections);
/* FreeBSD/mips has SVR4-style shared libraries. */
set_solib_svr4_fetch_link_map_offsets
(gdbarch, (gdbarch_ptr_bit (gdbarch) == 32 ?
mips_fbsd_ilp32_fetch_link_map_offsets :
mips_fbsd_lp64_fetch_link_map_offsets));
}
/* Provide a prototype to silence -Wmissing-prototypes. */
void _initialize_mips_fbsd_tdep (void);
void
_initialize_mips_fbsd_tdep (void)
{
gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_FREEBSD,
mips_fbsd_init_abi);
}