[deliverable/binutils-gdb.git] / gdb / arm-fbsd-tdep.c

/* Target-dependent code for FreeBSD/arm.

   Copyright (C) 2017-2019 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"

/* Local non-gdb includes.  */
#include "arm-fbsd-tdep.h"
#include "arm-tdep.h"
#include "auxv.h"
#include "elf/common.h"
#include "fbsd-tdep.h"
#include "gdbcore.h"
#include "osabi.h"
#include "solib-svr4.h"
#include "trad-frame.h"
#include "tramp-frame.h"

/* Register maps.  */

static const struct regcache_map_entry arm_fbsd_gregmap[] =
  {
    { 13, ARM_A1_REGNUM, 4 }, /* r0 ... r12 */
    { 1, ARM_SP_REGNUM, 4 },
    { 1, ARM_LR_REGNUM, 4 },
    { 1, ARM_PC_REGNUM, 4 },
    { 1, ARM_PS_REGNUM, 4 },
    { 0 }
  };

static const struct regcache_map_entry arm_fbsd_vfpregmap[] =
  {
    { 32, ARM_D0_REGNUM, 8 }, /* d0 ... d31 */
    { 1, ARM_FPSCR_REGNUM, 4 },
    { 0 }
  };

/* In a signal frame, sp points to a 'struct sigframe' which is
   defined as:

   struct sigframe {
	   siginfo_t	sf_si;
	   ucontext_t	sf_uc;
	   mcontext_vfp_t sf_vfp;
   };

   ucontext_t is defined as:

   struct __ucontext {
	   sigset_t	uc_sigmask;
	   mcontext_t	uc_mcontext;
	   ...
   };

   mcontext_t is defined as:

   struct {
	   unsigned int __gregs[17];
	   size_t       mc_vfp_size;
	   void         *mc_vfp_ptr;
	   ...
   };

   mcontext_vfp_t is defined as:

   struct {
	  uint64_t      mcv_reg[32];
	  uint32_t      mcv_fpscr;
   };

   If the VFP state is valid, then mc_vfp_ptr will point to sf_vfp in
   the sigframe, otherwise it is NULL.  There is no non-VFP floating
   point register state saved in the signal frame.  */

#define ARM_SIGFRAME_UCONTEXT_OFFSET	64
#define ARM_UCONTEXT_MCONTEXT_OFFSET	16
#define ARM_MCONTEXT_VFP_PTR_OFFSET	72

/* Implement the "init" method of struct tramp_frame.  */

static void
arm_fbsd_sigframe_init (const struct tramp_frame *self,
			struct frame_info *this_frame,
			struct trad_frame_cache *this_cache,
			CORE_ADDR func)
{
  struct gdbarch *gdbarch = get_frame_arch (this_frame);
  enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM);
  CORE_ADDR mcontext_addr = (sp
			     + ARM_SIGFRAME_UCONTEXT_OFFSET
			     + ARM_UCONTEXT_MCONTEXT_OFFSET);
  ULONGEST mcontext_vfp_addr;

  trad_frame_set_reg_regmap (this_cache, arm_fbsd_gregmap, mcontext_addr,
			     regcache_map_entry_size (arm_fbsd_gregmap));

  if (safe_read_memory_unsigned_integer (mcontext_addr
					 + ARM_MCONTEXT_VFP_PTR_OFFSET, 4,
					 byte_order,
					 &mcontext_vfp_addr)
      && mcontext_vfp_addr != 0)
    trad_frame_set_reg_regmap (this_cache, arm_fbsd_vfpregmap, mcontext_vfp_addr,
			       regcache_map_entry_size (arm_fbsd_vfpregmap));

  trad_frame_set_id (this_cache, frame_id_build (sp, func));
}

static const struct tramp_frame arm_fbsd_sigframe =
{
  SIGTRAMP_FRAME,
  4,
  {
    {0xe1a0000d, ULONGEST_MAX},		/* mov  r0, sp  */
    {0xe2800040, ULONGEST_MAX},		/* add  r0, r0, #SIGF_UC  */
    {0xe59f700c, ULONGEST_MAX},		/* ldr  r7, [pc, #12]  */
    {0xef0001a1, ULONGEST_MAX},		/* swi  SYS_sigreturn  */
    {TRAMP_SENTINEL_INSN, ULONGEST_MAX}
  },
  arm_fbsd_sigframe_init
};

/* Register set definitions.  */

const struct regset arm_fbsd_gregset =
  {
    arm_fbsd_gregmap,
    regcache_supply_regset, regcache_collect_regset
  };

const struct regset arm_fbsd_vfpregset =
  {
    arm_fbsd_vfpregmap,
    regcache_supply_regset, regcache_collect_regset
  };

/* Implement the "regset_from_core_section" gdbarch method.  */

static void
arm_fbsd_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", ARM_FBSD_SIZEOF_GREGSET, ARM_FBSD_SIZEOF_GREGSET,
      &arm_fbsd_gregset, NULL, cb_data);

  /* While FreeBSD/arm cores do contain a NT_FPREGSET / ".reg2"
     register set, it is not populated with register values by the
     kernel but just contains all zeroes.  */
  if (tdep->vfp_register_count > 0)
    cb (".reg-arm-vfp", ARM_FBSD_SIZEOF_VFPREGSET, ARM_FBSD_SIZEOF_VFPREGSET,
	&arm_fbsd_vfpregset, "VFP floating-point", cb_data);
}

/* Lookup a target description from a target's AT_HWCAP auxiliary
   vector.  */

const struct target_desc *
arm_fbsd_read_description_auxv (struct target_ops *target)
{
  CORE_ADDR arm_hwcap = 0;

  if (target_auxv_search (target, AT_FREEBSD_HWCAP, &arm_hwcap) != 1)
    return NULL;

  if (arm_hwcap & HWCAP_VFP)
    {
      if (arm_hwcap & HWCAP_NEON)
	return tdesc_arm_with_neon;
      else if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPD32))
	  == (HWCAP_VFPv3 | HWCAP_VFPD32))
	return tdesc_arm_with_vfpv3;
      else
	return tdesc_arm_with_vfpv2;
    }

  return NULL;
}

/* Implement the "core_read_description" gdbarch method.  */

static const struct target_desc *
arm_fbsd_core_read_description (struct gdbarch *gdbarch,
				struct target_ops *target,
				bfd *abfd)
{
  return arm_fbsd_read_description_auxv (target);
}

/* Implement the 'init_osabi' method of struct gdb_osabi_handler.  */

static void
arm_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
  struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

  /* Generic FreeBSD support.  */
  fbsd_init_abi (info, gdbarch);

  if (tdep->fp_model == ARM_FLOAT_AUTO)
    tdep->fp_model = ARM_FLOAT_SOFT_VFP;

  tramp_frame_prepend_unwinder (gdbarch, &arm_fbsd_sigframe);

  set_solib_svr4_fetch_link_map_offsets
    (gdbarch, svr4_ilp32_fetch_link_map_offsets);

  tdep->jb_pc = 24;
  tdep->jb_elt_size = 4;

  set_gdbarch_iterate_over_regset_sections
    (gdbarch, arm_fbsd_iterate_over_regset_sections);
  set_gdbarch_core_read_description (gdbarch, arm_fbsd_core_read_description);

  /* Single stepping.  */
  set_gdbarch_software_single_step (gdbarch, arm_software_single_step);
}

void
_initialize_arm_fbsd_tdep (void)
{
  gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_FREEBSD,
			  arm_fbsd_init_abi);
}
Commit	Line	Data
7176dfd2 JB	1	/* Target-dependent code for FreeBSD/arm.
7176dfd2 JB	2
42a4f53d	3	Copyright (C) 2017-2019 Free Software Foundation, Inc.
7176dfd2 JB	4
	5	This file is part of GDB.
	6
	7	This program is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 3 of the License, or
	10	(at your option) any later version.
	11
	12	This program is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with this program. If not, see <http://www.gnu.org/licenses/>. */
	19
	20	#include "defs.h"
	21
d55e5aa6	22	/* Local non-gdb includes. */
7176dfd2	23	#include "arm-fbsd-tdep.h"
d55e5aa6	24	#include "arm-tdep.h"
7176dfd2	25	#include "auxv.h"
d55e5aa6	26	#include "elf/common.h"
7176dfd2 JB	27	#include "fbsd-tdep.h"
	28	#include "gdbcore.h"
	29	#include "osabi.h"
	30	#include "solib-svr4.h"
	31	#include "trad-frame.h"
	32	#include "tramp-frame.h"
	33
7054e2ff JB	34	/* Register maps. */
	35
	36	static const struct regcache_map_entry arm_fbsd_gregmap[] =
	37	{
	38	{ 13, ARM_A1_REGNUM, 4 }, /* r0 ... r12 */
	39	{ 1, ARM_SP_REGNUM, 4 },
	40	{ 1, ARM_LR_REGNUM, 4 },
	41	{ 1, ARM_PC_REGNUM, 4 },
	42	{ 1, ARM_PS_REGNUM, 4 },
	43	{ 0 }
	44	};
	45
	46	static const struct regcache_map_entry arm_fbsd_vfpregmap[] =
	47	{
	48	{ 32, ARM_D0_REGNUM, 8 }, /* d0 ... d31 */
	49	{ 1, ARM_FPSCR_REGNUM, 4 },
	50	{ 0 }
	51	};
	52
7176dfd2 JB	53	/* In a signal frame, sp points to a 'struct sigframe' which is
	54	defined as:
	55
	56	struct sigframe {
	57	siginfo_t sf_si;
	58	ucontext_t sf_uc;
	59	mcontext_vfp_t sf_vfp;
	60	};
	61
	62	ucontext_t is defined as:
	63
	64	struct __ucontext {
	65	sigset_t uc_sigmask;
	66	mcontext_t uc_mcontext;
	67	...
	68	};
	69
	70	mcontext_t is defined as:
	71
	72	struct {
	73	unsigned int __gregs[17];
	74	size_t mc_vfp_size;
	75	void *mc_vfp_ptr;
	76	...
	77	};
	78
	79	mcontext_vfp_t is defined as:
	80
	81	struct {
	82	uint64_t mcv_reg[32];
	83	uint32_t mcv_fpscr;
	84	};
	85
	86	If the VFP state is valid, then mc_vfp_ptr will point to sf_vfp in
	87	the sigframe, otherwise it is NULL. There is no non-VFP floating
	88	point register state saved in the signal frame. */
	89
7176dfd2 JB	90	#define ARM_SIGFRAME_UCONTEXT_OFFSET 64
	91	#define ARM_UCONTEXT_MCONTEXT_OFFSET 16
	92	#define ARM_MCONTEXT_VFP_PTR_OFFSET 72
	93
	94	/* Implement the "init" method of struct tramp_frame. */
	95
	96	static void
	97	arm_fbsd_sigframe_init (const struct tramp_frame *self,
	98	struct frame_info *this_frame,
	99	struct trad_frame_cache *this_cache,
	100	CORE_ADDR func)
	101	{
	102	struct gdbarch *gdbarch = get_frame_arch (this_frame);
	103	enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
	104	CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM);
	105	CORE_ADDR mcontext_addr = (sp
	106	+ ARM_SIGFRAME_UCONTEXT_OFFSET
	107	+ ARM_UCONTEXT_MCONTEXT_OFFSET);
	108	ULONGEST mcontext_vfp_addr;
	109
7054e2ff JB	110	trad_frame_set_reg_regmap (this_cache, arm_fbsd_gregmap, mcontext_addr,
7054e2ff JB	111	regcache_map_entry_size (arm_fbsd_gregmap));
7176dfd2 JB	112
	113	if (safe_read_memory_unsigned_integer (mcontext_addr
	114	+ ARM_MCONTEXT_VFP_PTR_OFFSET, 4,
	115	byte_order,
	116	&mcontext_vfp_addr)
	117	&& mcontext_vfp_addr != 0)
7054e2ff JB	118	trad_frame_set_reg_regmap (this_cache, arm_fbsd_vfpregmap, mcontext_vfp_addr,
7054e2ff JB	119	regcache_map_entry_size (arm_fbsd_vfpregmap));
7176dfd2 JB	120
	121	trad_frame_set_id (this_cache, frame_id_build (sp, func));
	122	}
	123
	124	static const struct tramp_frame arm_fbsd_sigframe =
	125	{
	126	SIGTRAMP_FRAME,
	127	4,
	128	{
7bc02706 TT	129	{0xe1a0000d, ULONGEST_MAX}, /* mov r0, sp */
	130	{0xe2800040, ULONGEST_MAX}, /* add r0, r0, #SIGF_UC */
	131	{0xe59f700c, ULONGEST_MAX}, /* ldr r7, [pc, #12] */
	132	{0xef0001a1, ULONGEST_MAX}, /* swi SYS_sigreturn */
	133	{TRAMP_SENTINEL_INSN, ULONGEST_MAX}
7176dfd2 JB	134	},
	135	arm_fbsd_sigframe_init
	136	};
	137
7176dfd2 JB	138	/* Register set definitions. */
	139
	140	const struct regset arm_fbsd_gregset =
	141	{
	142	arm_fbsd_gregmap,
	143	regcache_supply_regset, regcache_collect_regset
	144	};
	145
	146	const struct regset arm_fbsd_vfpregset =
	147	{
	148	arm_fbsd_vfpregmap,
	149	regcache_supply_regset, regcache_collect_regset
	150	};
	151
	152	/* Implement the "regset_from_core_section" gdbarch method. */
	153
	154	static void
	155	arm_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
	156	iterate_over_regset_sections_cb *cb,
	157	void *cb_data,
	158	const struct regcache *regcache)
	159	{
	160	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	161
a616bb94 AH	162	cb (".reg", ARM_FBSD_SIZEOF_GREGSET, ARM_FBSD_SIZEOF_GREGSET,
a616bb94 AH	163	&arm_fbsd_gregset, NULL, cb_data);
7176dfd2 JB	164
	165	/* While FreeBSD/arm cores do contain a NT_FPREGSET / ".reg2"
	166	register set, it is not populated with register values by the
	167	kernel but just contains all zeroes. */
	168	if (tdep->vfp_register_count > 0)
a616bb94 AH	169	cb (".reg-arm-vfp", ARM_FBSD_SIZEOF_VFPREGSET, ARM_FBSD_SIZEOF_VFPREGSET,
a616bb94 AH	170	&arm_fbsd_vfpregset, "VFP floating-point", cb_data);
7176dfd2 JB	171	}
	172
	173	/* Lookup a target description from a target's AT_HWCAP auxiliary
	174	vector. */
	175
	176	const struct target_desc *
	177	arm_fbsd_read_description_auxv (struct target_ops *target)
	178	{
	179	CORE_ADDR arm_hwcap = 0;
	180
	181	if (target_auxv_search (target, AT_FREEBSD_HWCAP, &arm_hwcap) != 1)
	182	return NULL;
	183
	184	if (arm_hwcap & HWCAP_VFP)
	185	{
	186	if (arm_hwcap & HWCAP_NEON)
	187	return tdesc_arm_with_neon;
	188	else if ((arm_hwcap & (HWCAP_VFPv3 \| HWCAP_VFPD32))
	189	== (HWCAP_VFPv3 \| HWCAP_VFPD32))
	190	return tdesc_arm_with_vfpv3;
	191	else
	192	return tdesc_arm_with_vfpv2;
	193	}
	194
	195	return NULL;
	196	}
	197
	198	/* Implement the "core_read_description" gdbarch method. */
	199
	200	static const struct target_desc *
	201	arm_fbsd_core_read_description (struct gdbarch *gdbarch,
	202	struct target_ops *target,
	203	bfd *abfd)
	204	{
	205	return arm_fbsd_read_description_auxv (target);
	206	}
	207
	208	/* Implement the 'init_osabi' method of struct gdb_osabi_handler. */
	209
	210	static void
	211	arm_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	212	{
	213	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	214
	215	/* Generic FreeBSD support. */
	216	fbsd_init_abi (info, gdbarch);
	217
	218	if (tdep->fp_model == ARM_FLOAT_AUTO)
	219	tdep->fp_model = ARM_FLOAT_SOFT_VFP;
	220
	221	tramp_frame_prepend_unwinder (gdbarch, &arm_fbsd_sigframe);
	222
	223	set_solib_svr4_fetch_link_map_offsets
	224	(gdbarch, svr4_ilp32_fetch_link_map_offsets);
	225
	226	tdep->jb_pc = 24;
	227	tdep->jb_elt_size = 4;
	228
	229	set_gdbarch_iterate_over_regset_sections
	230	(gdbarch, arm_fbsd_iterate_over_regset_sections);
	231	set_gdbarch_core_read_description (gdbarch, arm_fbsd_core_read_description);
	232
	233	/* Single stepping. */
	234	set_gdbarch_software_single_step (gdbarch, arm_software_single_step);
235	}
236
237	void
238	_initialize_arm_fbsd_tdep (void)
239	{
240	gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_FREEBSD,
241	arm_fbsd_init_abi);
242	}