[thirdparty/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"

#include "elf/common.h"
#include "arm-tdep.h"
#include "arm-fbsd-tdep.h"
#include "auxv.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
4de283e4	22	#include "elf/common.h"
d55e5aa6	23	#include "arm-tdep.h"
4de283e4	24	#include "arm-fbsd-tdep.h"
7176dfd2 JB	25	#include "auxv.h"
	26	#include "fbsd-tdep.h"
	27	#include "gdbcore.h"
	28	#include "osabi.h"
	29	#include "solib-svr4.h"
	30	#include "trad-frame.h"
	31	#include "tramp-frame.h"
	32
7054e2ff JB	33	/* Register maps. */
	34
	35	static const struct regcache_map_entry arm_fbsd_gregmap[] =
	36	{
	37	{ 13, ARM_A1_REGNUM, 4 }, /* r0 ... r12 */
	38	{ 1, ARM_SP_REGNUM, 4 },
	39	{ 1, ARM_LR_REGNUM, 4 },
	40	{ 1, ARM_PC_REGNUM, 4 },
	41	{ 1, ARM_PS_REGNUM, 4 },
	42	{ 0 }
	43	};
	44
	45	static const struct regcache_map_entry arm_fbsd_vfpregmap[] =
	46	{
	47	{ 32, ARM_D0_REGNUM, 8 }, /* d0 ... d31 */
	48	{ 1, ARM_FPSCR_REGNUM, 4 },
	49	{ 0 }
	50	};
	51
7176dfd2 JB	52	/* In a signal frame, sp points to a 'struct sigframe' which is
	53	defined as:
	54
	55	struct sigframe {
	56	siginfo_t sf_si;
	57	ucontext_t sf_uc;
	58	mcontext_vfp_t sf_vfp;
	59	};
	60
	61	ucontext_t is defined as:
	62
	63	struct __ucontext {
	64	sigset_t uc_sigmask;
	65	mcontext_t uc_mcontext;
	66	...
	67	};
	68
	69	mcontext_t is defined as:
	70
	71	struct {
	72	unsigned int __gregs[17];
	73	size_t mc_vfp_size;
	74	void *mc_vfp_ptr;
	75	...
	76	};
	77
	78	mcontext_vfp_t is defined as:
	79
	80	struct {
	81	uint64_t mcv_reg[32];
	82	uint32_t mcv_fpscr;
	83	};
	84
	85	If the VFP state is valid, then mc_vfp_ptr will point to sf_vfp in
	86	the sigframe, otherwise it is NULL. There is no non-VFP floating
	87	point register state saved in the signal frame. */
	88
7176dfd2 JB	89	#define ARM_SIGFRAME_UCONTEXT_OFFSET 64
	90	#define ARM_UCONTEXT_MCONTEXT_OFFSET 16
	91	#define ARM_MCONTEXT_VFP_PTR_OFFSET 72
	92
	93	/* Implement the "init" method of struct tramp_frame. */
	94
	95	static void
	96	arm_fbsd_sigframe_init (const struct tramp_frame *self,
	97	struct frame_info *this_frame,
	98	struct trad_frame_cache *this_cache,
	99	CORE_ADDR func)
	100	{
	101	struct gdbarch *gdbarch = get_frame_arch (this_frame);
	102	enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
	103	CORE_ADDR sp = get_frame_register_unsigned (this_frame, ARM_SP_REGNUM);
	104	CORE_ADDR mcontext_addr = (sp
	105	+ ARM_SIGFRAME_UCONTEXT_OFFSET
	106	+ ARM_UCONTEXT_MCONTEXT_OFFSET);
	107	ULONGEST mcontext_vfp_addr;
	108
7054e2ff JB	109	trad_frame_set_reg_regmap (this_cache, arm_fbsd_gregmap, mcontext_addr,
7054e2ff JB	110	regcache_map_entry_size (arm_fbsd_gregmap));
7176dfd2 JB	111
	112	if (safe_read_memory_unsigned_integer (mcontext_addr
	113	+ ARM_MCONTEXT_VFP_PTR_OFFSET, 4,
	114	byte_order,
	115	&mcontext_vfp_addr)
	116	&& mcontext_vfp_addr != 0)
7054e2ff JB	117	trad_frame_set_reg_regmap (this_cache, arm_fbsd_vfpregmap, mcontext_vfp_addr,
7054e2ff JB	118	regcache_map_entry_size (arm_fbsd_vfpregmap));
7176dfd2 JB	119
	120	trad_frame_set_id (this_cache, frame_id_build (sp, func));
	121	}
	122
	123	static const struct tramp_frame arm_fbsd_sigframe =
	124	{
	125	SIGTRAMP_FRAME,
	126	4,
	127	{
7bc02706 TT	128	{0xe1a0000d, ULONGEST_MAX}, /* mov r0, sp */
	129	{0xe2800040, ULONGEST_MAX}, /* add r0, r0, #SIGF_UC */
	130	{0xe59f700c, ULONGEST_MAX}, /* ldr r7, [pc, #12] */
	131	{0xef0001a1, ULONGEST_MAX}, /* swi SYS_sigreturn */
	132	{TRAMP_SENTINEL_INSN, ULONGEST_MAX}
7176dfd2 JB	133	},
	134	arm_fbsd_sigframe_init
	135	};
	136
7176dfd2 JB	137	/* Register set definitions. */
	138
	139	const struct regset arm_fbsd_gregset =
	140	{
	141	arm_fbsd_gregmap,
	142	regcache_supply_regset, regcache_collect_regset
	143	};
	144
	145	const struct regset arm_fbsd_vfpregset =
	146	{
	147	arm_fbsd_vfpregmap,
	148	regcache_supply_regset, regcache_collect_regset
	149	};
	150
	151	/* Implement the "regset_from_core_section" gdbarch method. */
	152
	153	static void
	154	arm_fbsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
	155	iterate_over_regset_sections_cb *cb,
	156	void *cb_data,
	157	const struct regcache *regcache)
	158	{
	159	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	160
a616bb94 AH	161	cb (".reg", ARM_FBSD_SIZEOF_GREGSET, ARM_FBSD_SIZEOF_GREGSET,
a616bb94 AH	162	&arm_fbsd_gregset, NULL, cb_data);
7176dfd2 JB	163
	164	/* While FreeBSD/arm cores do contain a NT_FPREGSET / ".reg2"
	165	register set, it is not populated with register values by the
	166	kernel but just contains all zeroes. */
	167	if (tdep->vfp_register_count > 0)
a616bb94 AH	168	cb (".reg-arm-vfp", ARM_FBSD_SIZEOF_VFPREGSET, ARM_FBSD_SIZEOF_VFPREGSET,
a616bb94 AH	169	&arm_fbsd_vfpregset, "VFP floating-point", cb_data);
7176dfd2 JB	170	}
	171
	172	/* Lookup a target description from a target's AT_HWCAP auxiliary
	173	vector. */
	174
	175	const struct target_desc *
	176	arm_fbsd_read_description_auxv (struct target_ops *target)
	177	{
	178	CORE_ADDR arm_hwcap = 0;
	179
	180	if (target_auxv_search (target, AT_FREEBSD_HWCAP, &arm_hwcap) != 1)
	181	return NULL;
	182
	183	if (arm_hwcap & HWCAP_VFP)
	184	{
	185	if (arm_hwcap & HWCAP_NEON)
	186	return tdesc_arm_with_neon;
	187	else if ((arm_hwcap & (HWCAP_VFPv3 \| HWCAP_VFPD32))
	188	== (HWCAP_VFPv3 \| HWCAP_VFPD32))
	189	return tdesc_arm_with_vfpv3;
	190	else
	191	return tdesc_arm_with_vfpv2;
	192	}
	193
	194	return NULL;
	195	}
	196
	197	/* Implement the "core_read_description" gdbarch method. */
	198
	199	static const struct target_desc *
	200	arm_fbsd_core_read_description (struct gdbarch *gdbarch,
	201	struct target_ops *target,
	202	bfd *abfd)
	203	{
	204	return arm_fbsd_read_description_auxv (target);
	205	}
	206
	207	/* Implement the 'init_osabi' method of struct gdb_osabi_handler. */
	208
	209	static void
	210	arm_fbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	211	{
	212	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
	213
	214	/* Generic FreeBSD support. */
	215	fbsd_init_abi (info, gdbarch);
	216
	217	if (tdep->fp_model == ARM_FLOAT_AUTO)
	218	tdep->fp_model = ARM_FLOAT_SOFT_VFP;
	219
	220	tramp_frame_prepend_unwinder (gdbarch, &arm_fbsd_sigframe);
	221
	222	set_solib_svr4_fetch_link_map_offsets
	223	(gdbarch, svr4_ilp32_fetch_link_map_offsets);
	224
	225	tdep->jb_pc = 24;
	226	tdep->jb_elt_size = 4;
	227
	228	set_gdbarch_iterate_over_regset_sections
	229	(gdbarch, arm_fbsd_iterate_over_regset_sections);
	230	set_gdbarch_core_read_description (gdbarch, arm_fbsd_core_read_description);
	231
	232	/* Single stepping. */
	233	set_gdbarch_software_single_step (gdbarch, arm_software_single_step);
234	}
235
236	void
237	_initialize_arm_fbsd_tdep (void)
238	{
239	gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_FREEBSD,
240	arm_fbsd_init_abi);
241	}