gdb/arm-fbsd-tdep.c - binutils-gdb - Git at Google

 /* Target-dependent code for FreeBSD/arm.

    Copyright (C) 2017-2022 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 "target-descriptions.h"
 #include "aarch32-tdep.h"
 #include "arm-tdep.h"
 #include "arm-fbsd-tdep.h"
 #include "auxv.h"
 #include "fbsd-tdep.h"
 #include "gdbcore.h"
 #include "inferior.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 "iterate_over_regset_sections" 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)
 {
   arm_gdbarch_tdep *tdep = (arm_gdbarch_tdep *) gdbarch_tdep (gdbarch);

   cb (".reg", ARM_FBSD_SIZEOF_GREGSET, ARM_FBSD_SIZEOF_GREGSET,
       &arm_fbsd_gregset, NULL, cb_data);

   if (tdep->tls_regnum > 0)
     {
       const struct regcache_map_entry arm_fbsd_tlsregmap[] =
 	{
 	  { 1, tdep->tls_regnum, 4 },
 	  { 0 }
 	};

       const struct regset arm_fbsd_tlsregset =
 	{
 	  arm_fbsd_tlsregmap,
 	  regcache_supply_regset, regcache_collect_regset
 	};

       cb (".reg-aarch-tls", ARM_FBSD_SIZEOF_TLSREGSET, ARM_FBSD_SIZEOF_TLSREGSET,
 	  &arm_fbsd_tlsregset, 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, bool tls)
 {
   CORE_ADDR arm_hwcap = 0;

   if (target_auxv_search (target, AT_FREEBSD_HWCAP, &arm_hwcap) != 1)
     return arm_read_description (ARM_FP_TYPE_NONE, tls);

   if (arm_hwcap & HWCAP_VFP)
     {
       if (arm_hwcap & HWCAP_NEON)
 	return aarch32_read_description ();
       else if ((arm_hwcap & (HWCAP_VFPv3 | HWCAP_VFPD32))
 	       == (HWCAP_VFPv3 | HWCAP_VFPD32))
 	return arm_read_description (ARM_FP_TYPE_VFPV3, tls);
       else
 	return arm_read_description (ARM_FP_TYPE_VFPV2, tls);
     }

   return arm_read_description (ARM_FP_TYPE_NONE, tls);
 }

 /* 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)
 {
   asection *tls = bfd_get_section_by_name (abfd, ".reg-aarch-tls");

   return arm_fbsd_read_description_auxv (target, tls != nullptr);
 }

 /* Implement the get_thread_local_address gdbarch method.  */

 static CORE_ADDR
 arm_fbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
 				   CORE_ADDR lm_addr, CORE_ADDR offset)
 {
   arm_gdbarch_tdep *tdep = (arm_gdbarch_tdep *) gdbarch_tdep (gdbarch);
   struct regcache *regcache;

   regcache = get_thread_arch_regcache (current_inferior ()->process_target (),
 				       ptid, gdbarch);

   target_fetch_registers (regcache, tdep->tls_regnum);

   ULONGEST tpidruro;
   if (regcache->cooked_read (tdep->tls_regnum, &tpidruro) != REG_VALID)
     error (_("Unable to fetch %%tpidruro"));

   /* %tpidruro points to the TCB whose first member is the dtv
       pointer.  */
   CORE_ADDR dtv_addr = tpidruro;
   return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
 }

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

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

   if (tdep->tls_regnum > 0)
     {
       set_gdbarch_fetch_tls_load_module_address (gdbarch,
 						 svr4_fetch_objfile_link_map);
       set_gdbarch_get_thread_local_address (gdbarch,
 					    arm_fbsd_get_thread_local_address);
     }

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

 void _initialize_arm_fbsd_tdep ();
 void
 _initialize_arm_fbsd_tdep ()
 {
   gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_FREEBSD,
 			  arm_fbsd_init_abi);
 }
	/* Target-dependent code for FreeBSD/arm.

	Copyright (C) 2017-2022 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 "target-descriptions.h"
	#include "aarch32-tdep.h"
	#include "arm-tdep.h"
	#include "arm-fbsd-tdep.h"
	#include "auxv.h"
	#include "fbsd-tdep.h"
	#include "gdbcore.h"
	#include "inferior.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 "iterate_over_regset_sections" 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)
	{
	arm_gdbarch_tdep tdep = (arm_gdbarch_tdep ) gdbarch_tdep (gdbarch);

	cb (".reg", ARM_FBSD_SIZEOF_GREGSET, ARM_FBSD_SIZEOF_GREGSET,
	&arm_fbsd_gregset, NULL, cb_data);

	if (tdep->tls_regnum > 0)
	{
	const struct regcache_map_entry arm_fbsd_tlsregmap[] =
	{
	{ 1, tdep->tls_regnum, 4 },
	{ 0 }
	};

	const struct regset arm_fbsd_tlsregset =
	{
	arm_fbsd_tlsregmap,
	regcache_supply_regset, regcache_collect_regset
	};

	cb (".reg-aarch-tls", ARM_FBSD_SIZEOF_TLSREGSET, ARM_FBSD_SIZEOF_TLSREGSET,
	&arm_fbsd_tlsregset, 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, bool tls)
	{
	CORE_ADDR arm_hwcap = 0;

	if (target_auxv_search (target, AT_FREEBSD_HWCAP, &arm_hwcap) != 1)
	return arm_read_description (ARM_FP_TYPE_NONE, tls);

	if (arm_hwcap & HWCAP_VFP)
	{
	if (arm_hwcap & HWCAP_NEON)
	return aarch32_read_description ();
	else if ((arm_hwcap & (HWCAP_VFPv3 \| HWCAP_VFPD32))
	== (HWCAP_VFPv3 \| HWCAP_VFPD32))
	return arm_read_description (ARM_FP_TYPE_VFPV3, tls);
	else
	return arm_read_description (ARM_FP_TYPE_VFPV2, tls);
	}

	return arm_read_description (ARM_FP_TYPE_NONE, tls);
	}

	/* 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)
	{
	asection *tls = bfd_get_section_by_name (abfd, ".reg-aarch-tls");

	return arm_fbsd_read_description_auxv (target, tls != nullptr);
	}

	/* Implement the get_thread_local_address gdbarch method. */

	static CORE_ADDR
	arm_fbsd_get_thread_local_address (struct gdbarch *gdbarch, ptid_t ptid,
	CORE_ADDR lm_addr, CORE_ADDR offset)
	{
	arm_gdbarch_tdep tdep = (arm_gdbarch_tdep ) gdbarch_tdep (gdbarch);
	struct regcache *regcache;

	regcache = get_thread_arch_regcache (current_inferior ()->process_target (),
	ptid, gdbarch);

	target_fetch_registers (regcache, tdep->tls_regnum);

	ULONGEST tpidruro;
	if (regcache->cooked_read (tdep->tls_regnum, &tpidruro) != REG_VALID)
	error (_("Unable to fetch %%tpidruro"));

	/* %tpidruro points to the TCB whose first member is the dtv
	pointer. */
	CORE_ADDR dtv_addr = tpidruro;
	return fbsd_get_thread_local_address (gdbarch, dtv_addr, lm_addr, offset);
	}

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

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

	if (tdep->tls_regnum > 0)
	{
	set_gdbarch_fetch_tls_load_module_address (gdbarch,
	svr4_fetch_objfile_link_map);
	set_gdbarch_get_thread_local_address (gdbarch,
	arm_fbsd_get_thread_local_address);
	}

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

	void _initialize_arm_fbsd_tdep ();
	void
	_initialize_arm_fbsd_tdep ()
	{
	gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_FREEBSD,
	arm_fbsd_init_abi);
	}