gdb/sparc-netbsd-tdep.c - binutils-gdb - Git at Google

 /* Target-dependent code for NetBSD/sparc.

    Copyright (C) 2002-2021 Free Software Foundation, Inc.
    Contributed by Wasabi Systems, 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 "frame.h"
 #include "frame-unwind.h"
 #include "gdbcore.h"
 #include "gdbtypes.h"
 #include "osabi.h"
 #include "regcache.h"
 #include "regset.h"
 #include "solib-svr4.h"
 #include "symtab.h"
 #include "trad-frame.h"
 #include "gdbarch.h"

 #include "sparc-tdep.h"
 #include "netbsd-tdep.h"

 /* Macros to extract fields from SPARC instructions.  */
 #define X_RS1(i) (((i) >> 14) & 0x1f)
 #define X_RS2(i) ((i) & 0x1f)
 #define X_I(i) (((i) >> 13) & 1)

 const struct sparc_gregmap sparc32nbsd_gregmap =
 {
   0 * 4,			/* %psr */
   1 * 4,			/* %pc */
   2 * 4,			/* %npc */
   3 * 4,			/* %y */
   -1,				/* %wim */
   -1,				/* %tbr */
   5 * 4,			/* %g1 */
   -1				/* %l0 */
 };

 static void
 sparc32nbsd_supply_gregset (const struct regset *regset,
 			    struct regcache *regcache,
 			    int regnum, const void *gregs, size_t len)
 {
   sparc32_supply_gregset (&sparc32nbsd_gregmap, regcache, regnum, gregs);

   /* Traditional NetBSD core files don't use multiple register sets.
      Instead, the general-purpose and floating-point registers are
      lumped together in a single section.  */
   if (len >= 212)
     sparc32_supply_fpregset (&sparc32_bsd_fpregmap, regcache, regnum,
 			     (const char *) gregs + 80);
 }

 static void
 sparc32nbsd_supply_fpregset (const struct regset *regset,
 			     struct regcache *regcache,
 			     int regnum, const void *fpregs, size_t len)
 {
   sparc32_supply_fpregset (&sparc32_bsd_fpregmap, regcache, regnum, fpregs);
 }


 /* Signal trampolines.  */

 /* The following variables describe the location of an on-stack signal
    trampoline.  The current values correspond to the memory layout for
    NetBSD 1.3 and up.  These shouldn't be necessary for NetBSD 2.0 and
    up, since NetBSD uses signal trampolines provided by libc now.  */

 static const CORE_ADDR sparc32nbsd_sigtramp_start = 0xeffffef0;
 static const CORE_ADDR sparc32nbsd_sigtramp_end = 0xeffffff0;

 static int
 sparc32nbsd_pc_in_sigtramp (CORE_ADDR pc, const char *name)
 {
   if (pc >= sparc32nbsd_sigtramp_start && pc < sparc32nbsd_sigtramp_end)
     return 1;

   return nbsd_pc_in_sigtramp (pc, name);
 }

 trad_frame_saved_reg *
 sparc32nbsd_sigcontext_saved_regs (struct frame_info *this_frame)
 {
   struct gdbarch *gdbarch = get_frame_arch (this_frame);
   trad_frame_saved_reg *saved_regs;
   CORE_ADDR addr, sigcontext_addr;
   int regnum, delta;
   ULONGEST psr;

   saved_regs = trad_frame_alloc_saved_regs (this_frame);

   /* We find the appropriate instance of `struct sigcontext' at a
      fixed offset in the signal frame.  */
   addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
   sigcontext_addr = addr + 64 + 16;

   /* The registers are saved in bits and pieces scattered all over the
      place.  The code below records their location on the assumption
      that the part of the signal trampoline that saves the state has
      been executed.  */

   saved_regs[SPARC_SP_REGNUM].set_addr (sigcontext_addr + 8);
   saved_regs[SPARC32_PC_REGNUM].set_addr (sigcontext_addr + 12);
   saved_regs[SPARC32_NPC_REGNUM].set_addr (sigcontext_addr + 16);
   saved_regs[SPARC32_PSR_REGNUM].set_addr (sigcontext_addr + 20);
   saved_regs[SPARC_G1_REGNUM].set_addr (sigcontext_addr + 24);
   saved_regs[SPARC_O0_REGNUM].set_addr (sigcontext_addr + 28);

   /* The remaining `global' registers and %y are saved in the `local'
      registers.  */
   delta = SPARC_L0_REGNUM - SPARC_G0_REGNUM;
   for (regnum = SPARC_G2_REGNUM; regnum <= SPARC_G7_REGNUM; regnum++)
     saved_regs[regnum].set_realreg (regnum + delta);
   saved_regs[SPARC32_Y_REGNUM].set_realreg (SPARC_L1_REGNUM);

   /* The remaining `out' registers can be found in the current frame's
      `in' registers.  */
   delta = SPARC_I0_REGNUM - SPARC_O0_REGNUM;
   for (regnum = SPARC_O1_REGNUM; regnum <= SPARC_O5_REGNUM; regnum++)
     saved_regs[regnum].set_realreg (regnum + delta);
   saved_regs[SPARC_O7_REGNUM].set_realreg (SPARC_I7_REGNUM);

   /* The `local' and `in' registers have been saved in the register
      save area.  */
   addr = saved_regs[SPARC_SP_REGNUM].addr ();
   addr = get_frame_memory_unsigned (this_frame, addr, 4);
   for (regnum = SPARC_L0_REGNUM;
        regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
     saved_regs[regnum].set_addr (addr);

   /* Handle StackGhost.  */
   {
     ULONGEST wcookie = sparc_fetch_wcookie (gdbarch);

     if (wcookie != 0)
       {
 	ULONGEST i7;

 	addr = saved_regs[SPARC_I7_REGNUM].addr ();
 	i7 = get_frame_memory_unsigned (this_frame, addr, 4);
 	saved_regs[SPARC_I7_REGNUM].set_value (i7 ^ wcookie);
       }
   }

   /* The floating-point registers are only saved if the EF bit in %prs
      has been set.  */

 #define PSR_EF	0x00001000

   addr = saved_regs[SPARC32_PSR_REGNUM].addr ();
   psr = get_frame_memory_unsigned (this_frame, addr, 4);
   if (psr & PSR_EF)
     {
       CORE_ADDR sp;

       sp = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
       saved_regs[SPARC32_FSR_REGNUM].set_addr (sp + 96);
       for (regnum = SPARC_F0_REGNUM, addr = sp + 96 + 8;
 	   regnum <= SPARC_F31_REGNUM; regnum++, addr += 4)
 	saved_regs[regnum].set_addr (addr);
     }

   return saved_regs;
 }

 static struct sparc_frame_cache *
 sparc32nbsd_sigcontext_frame_cache (struct frame_info *this_frame,
 				    void **this_cache)
 {
   struct sparc_frame_cache *cache;
   CORE_ADDR addr;

   if (*this_cache)
     return (struct sparc_frame_cache *) *this_cache;

   cache = sparc_frame_cache (this_frame, this_cache);
   gdb_assert (cache == *this_cache);

   /* If we couldn't find the frame's function, we're probably dealing
      with an on-stack signal trampoline.  */
   if (cache->pc == 0)
     {
       cache->pc = sparc32nbsd_sigtramp_start;

       /* Since we couldn't find the frame's function, the cache was
 	 initialized under the assumption that we're frameless.  */
       sparc_record_save_insn (cache);
       addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
       cache->base = addr;
     }

   cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (this_frame);

   return cache;
 }

 static void
 sparc32nbsd_sigcontext_frame_this_id (struct frame_info *this_frame,
 				      void **this_cache,
 				      struct frame_id *this_id)
 {
   struct sparc_frame_cache *cache =
     sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);

   (*this_id) = frame_id_build (cache->base, cache->pc);
 }

 static struct value *
 sparc32nbsd_sigcontext_frame_prev_register (struct frame_info *this_frame,
 					    void **this_cache, int regnum)
 {
   struct sparc_frame_cache *cache =
     sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);

   return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
 }

 static int
 sparc32nbsd_sigcontext_frame_sniffer (const struct frame_unwind *self,
 				      struct frame_info *this_frame,
 				      void **this_cache)
 {
   CORE_ADDR pc = get_frame_pc (this_frame);
   const char *name;

   find_pc_partial_function (pc, &name, NULL, NULL);
   if (sparc32nbsd_pc_in_sigtramp (pc, name))
     {
       if (name == NULL || !startswith (name, "__sigtramp_sigcontext"))
 	return 1;
     }

   return 0;
 }

 static const struct frame_unwind sparc32nbsd_sigcontext_frame_unwind =
 {
   "sparc32 netbsd sigcontext",
   SIGTRAMP_FRAME,
   default_frame_unwind_stop_reason,
   sparc32nbsd_sigcontext_frame_this_id,
   sparc32nbsd_sigcontext_frame_prev_register,
   NULL,
   sparc32nbsd_sigcontext_frame_sniffer
 };

 /* Return the address of a system call's alternative return
    address.  */

 CORE_ADDR
 sparcnbsd_step_trap (struct frame_info *frame, unsigned long insn)
 {
   if ((X_I (insn) == 0 && X_RS1 (insn) == 0 && X_RS2 (insn) == 0)
       || (X_I (insn) == 1 && X_RS1 (insn) == 0 && (insn & 0x7f) == 0))
     {
       /* "New" system call.  */
       ULONGEST number = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);

       if (number & 0x400)
 	return get_frame_register_unsigned (frame, SPARC_G2_REGNUM);
       if (number & 0x800)
 	return get_frame_register_unsigned (frame, SPARC_G7_REGNUM);
     }

   return 0;
 }


 static const struct regset sparc32nbsd_gregset =
   {
     NULL, sparc32nbsd_supply_gregset, NULL
   };

 static const struct regset sparc32nbsd_fpregset =
   {
     NULL, sparc32nbsd_supply_fpregset, NULL
   };

 void
 sparc32nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

   nbsd_init_abi (info, gdbarch);

   /* NetBSD doesn't support the 128-bit `long double' from the psABI.  */
   set_gdbarch_long_double_bit (gdbarch, 64);
   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);

   tdep->gregset = &sparc32nbsd_gregset;
   tdep->sizeof_gregset = 20 * 4;

   tdep->fpregset = &sparc32nbsd_fpregset;
   tdep->sizeof_fpregset = 33 * 4;

   /* Make sure we can single-step "new" syscalls.  */
   tdep->step_trap = sparcnbsd_step_trap;

   frame_unwind_append_unwinder (gdbarch, &sparc32nbsd_sigcontext_frame_unwind);

   set_solib_svr4_fetch_link_map_offsets
     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 }

 void _initialize_sparcnbsd_tdep ();
 void
 _initialize_sparcnbsd_tdep ()
 {
   gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD,
 			  sparc32nbsd_init_abi);
 }
	/* Target-dependent code for NetBSD/sparc.

	Copyright (C) 2002-2021 Free Software Foundation, Inc.
	Contributed by Wasabi Systems, 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 "frame.h"
	#include "frame-unwind.h"
	#include "gdbcore.h"
	#include "gdbtypes.h"
	#include "osabi.h"
	#include "regcache.h"
	#include "regset.h"
	#include "solib-svr4.h"
	#include "symtab.h"
	#include "trad-frame.h"
	#include "gdbarch.h"

	#include "sparc-tdep.h"
	#include "netbsd-tdep.h"

	/* Macros to extract fields from SPARC instructions. */
	#define X_RS1(i) (((i) >> 14) & 0x1f)
	#define X_RS2(i) ((i) & 0x1f)
	#define X_I(i) (((i) >> 13) & 1)

	const struct sparc_gregmap sparc32nbsd_gregmap =
	{
	0 * 4, /* %psr */
	1 * 4, /* %pc */
	2 * 4, /* %npc */
	3 * 4, /* %y */
	-1, /* %wim */
	-1, /* %tbr */
	5 * 4, /* %g1 */
	-1 /* %l0 */
	};

	static void
	sparc32nbsd_supply_gregset (const struct regset *regset,
	struct regcache *regcache,
	int regnum, const void *gregs, size_t len)
	{
	sparc32_supply_gregset (&sparc32nbsd_gregmap, regcache, regnum, gregs);

	/* Traditional NetBSD core files don't use multiple register sets.
	Instead, the general-purpose and floating-point registers are
	lumped together in a single section. */
	if (len >= 212)
	sparc32_supply_fpregset (&sparc32_bsd_fpregmap, regcache, regnum,
	(const char *) gregs + 80);
	}

	static void
	sparc32nbsd_supply_fpregset (const struct regset *regset,
	struct regcache *regcache,
	int regnum, const void *fpregs, size_t len)
	{
	sparc32_supply_fpregset (&sparc32_bsd_fpregmap, regcache, regnum, fpregs);
	}


	/* Signal trampolines. */

	/* The following variables describe the location of an on-stack signal
	trampoline. The current values correspond to the memory layout for
	NetBSD 1.3 and up. These shouldn't be necessary for NetBSD 2.0 and
	up, since NetBSD uses signal trampolines provided by libc now. */

	static const CORE_ADDR sparc32nbsd_sigtramp_start = 0xeffffef0;
	static const CORE_ADDR sparc32nbsd_sigtramp_end = 0xeffffff0;

	static int
	sparc32nbsd_pc_in_sigtramp (CORE_ADDR pc, const char *name)
	{
	if (pc >= sparc32nbsd_sigtramp_start && pc < sparc32nbsd_sigtramp_end)
	return 1;

	return nbsd_pc_in_sigtramp (pc, name);
	}

	trad_frame_saved_reg *
	sparc32nbsd_sigcontext_saved_regs (struct frame_info *this_frame)
	{
	struct gdbarch *gdbarch = get_frame_arch (this_frame);
	trad_frame_saved_reg *saved_regs;
	CORE_ADDR addr, sigcontext_addr;
	int regnum, delta;
	ULONGEST psr;

	saved_regs = trad_frame_alloc_saved_regs (this_frame);

	/* We find the appropriate instance of `struct sigcontext' at a
	fixed offset in the signal frame. */
	addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
	sigcontext_addr = addr + 64 + 16;

	/* The registers are saved in bits and pieces scattered all over the
	place. The code below records their location on the assumption
	that the part of the signal trampoline that saves the state has
	been executed. */

	saved_regs[SPARC_SP_REGNUM].set_addr (sigcontext_addr + 8);
	saved_regs[SPARC32_PC_REGNUM].set_addr (sigcontext_addr + 12);
	saved_regs[SPARC32_NPC_REGNUM].set_addr (sigcontext_addr + 16);
	saved_regs[SPARC32_PSR_REGNUM].set_addr (sigcontext_addr + 20);
	saved_regs[SPARC_G1_REGNUM].set_addr (sigcontext_addr + 24);
	saved_regs[SPARC_O0_REGNUM].set_addr (sigcontext_addr + 28);

	/* The remaining `global' registers and %y are saved in the `local'
	registers. */
	delta = SPARC_L0_REGNUM - SPARC_G0_REGNUM;
	for (regnum = SPARC_G2_REGNUM; regnum <= SPARC_G7_REGNUM; regnum++)
	saved_regs[regnum].set_realreg (regnum + delta);
	saved_regs[SPARC32_Y_REGNUM].set_realreg (SPARC_L1_REGNUM);

	/* The remaining `out' registers can be found in the current frame's
	`in' registers. */
	delta = SPARC_I0_REGNUM - SPARC_O0_REGNUM;
	for (regnum = SPARC_O1_REGNUM; regnum <= SPARC_O5_REGNUM; regnum++)
	saved_regs[regnum].set_realreg (regnum + delta);
	saved_regs[SPARC_O7_REGNUM].set_realreg (SPARC_I7_REGNUM);

	/* The `local' and `in' registers have been saved in the register
	save area. */
	addr = saved_regs[SPARC_SP_REGNUM].addr ();
	addr = get_frame_memory_unsigned (this_frame, addr, 4);
	for (regnum = SPARC_L0_REGNUM;
	regnum <= SPARC_I7_REGNUM; regnum++, addr += 4)
	saved_regs[regnum].set_addr (addr);

	/* Handle StackGhost. */
	{
	ULONGEST wcookie = sparc_fetch_wcookie (gdbarch);

	if (wcookie != 0)
	{
	ULONGEST i7;

	addr = saved_regs[SPARC_I7_REGNUM].addr ();
	i7 = get_frame_memory_unsigned (this_frame, addr, 4);
	saved_regs[SPARC_I7_REGNUM].set_value (i7 ^ wcookie);
	}
	}

	/* The floating-point registers are only saved if the EF bit in %prs
	has been set. */

	#define PSR_EF 0x00001000

	addr = saved_regs[SPARC32_PSR_REGNUM].addr ();
	psr = get_frame_memory_unsigned (this_frame, addr, 4);
	if (psr & PSR_EF)
	{
	CORE_ADDR sp;

	sp = get_frame_register_unsigned (this_frame, SPARC_SP_REGNUM);
	saved_regs[SPARC32_FSR_REGNUM].set_addr (sp + 96);
	for (regnum = SPARC_F0_REGNUM, addr = sp + 96 + 8;
	regnum <= SPARC_F31_REGNUM; regnum++, addr += 4)
	saved_regs[regnum].set_addr (addr);
	}

	return saved_regs;
	}

	static struct sparc_frame_cache *
	sparc32nbsd_sigcontext_frame_cache (struct frame_info *this_frame,
	void **this_cache)
	{
	struct sparc_frame_cache *cache;
	CORE_ADDR addr;

	if (*this_cache)
	return (struct sparc_frame_cache ) this_cache;

	cache = sparc_frame_cache (this_frame, this_cache);
	gdb_assert (cache == *this_cache);

	/* If we couldn't find the frame's function, we're probably dealing
	with an on-stack signal trampoline. */
	if (cache->pc == 0)
	{
	cache->pc = sparc32nbsd_sigtramp_start;

	/* Since we couldn't find the frame's function, the cache was
	initialized under the assumption that we're frameless. */
	sparc_record_save_insn (cache);
	addr = get_frame_register_unsigned (this_frame, SPARC_FP_REGNUM);
	cache->base = addr;
	}

	cache->saved_regs = sparc32nbsd_sigcontext_saved_regs (this_frame);

	return cache;
	}

	static void
	sparc32nbsd_sigcontext_frame_this_id (struct frame_info *this_frame,
	void **this_cache,
	struct frame_id *this_id)
	{
	struct sparc_frame_cache *cache =
	sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);

	(*this_id) = frame_id_build (cache->base, cache->pc);
	}

	static struct value *
	sparc32nbsd_sigcontext_frame_prev_register (struct frame_info *this_frame,
	void **this_cache, int regnum)
	{
	struct sparc_frame_cache *cache =
	sparc32nbsd_sigcontext_frame_cache (this_frame, this_cache);

	return trad_frame_get_prev_register (this_frame, cache->saved_regs, regnum);
	}

	static int
	sparc32nbsd_sigcontext_frame_sniffer (const struct frame_unwind *self,
	struct frame_info *this_frame,
	void **this_cache)
	{
	CORE_ADDR pc = get_frame_pc (this_frame);
	const char *name;

	find_pc_partial_function (pc, &name, NULL, NULL);
	if (sparc32nbsd_pc_in_sigtramp (pc, name))
	{
	if (name == NULL \|\| !startswith (name, "__sigtramp_sigcontext"))
	return 1;
	}

	return 0;
	}

	static const struct frame_unwind sparc32nbsd_sigcontext_frame_unwind =
	{
	"sparc32 netbsd sigcontext",
	SIGTRAMP_FRAME,
	default_frame_unwind_stop_reason,
	sparc32nbsd_sigcontext_frame_this_id,
	sparc32nbsd_sigcontext_frame_prev_register,
	NULL,
	sparc32nbsd_sigcontext_frame_sniffer
	};

	/* Return the address of a system call's alternative return
	address. */

	CORE_ADDR
	sparcnbsd_step_trap (struct frame_info *frame, unsigned long insn)
	{
	if ((X_I (insn) == 0 && X_RS1 (insn) == 0 && X_RS2 (insn) == 0)
	\|\| (X_I (insn) == 1 && X_RS1 (insn) == 0 && (insn & 0x7f) == 0))
	{
	/* "New" system call. */
	ULONGEST number = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);

	if (number & 0x400)
	return get_frame_register_unsigned (frame, SPARC_G2_REGNUM);
	if (number & 0x800)
	return get_frame_register_unsigned (frame, SPARC_G7_REGNUM);
	}

	return 0;
	}


	static const struct regset sparc32nbsd_gregset =
	{
	NULL, sparc32nbsd_supply_gregset, NULL
	};

	static const struct regset sparc32nbsd_fpregset =
	{
	NULL, sparc32nbsd_supply_fpregset, NULL
	};

	void
	sparc32nbsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	{
	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

	nbsd_init_abi (info, gdbarch);

	/* NetBSD doesn't support the 128-bit `long double' from the psABI. */
	set_gdbarch_long_double_bit (gdbarch, 64);
	set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);

	tdep->gregset = &sparc32nbsd_gregset;
	tdep->sizeof_gregset = 20 * 4;

	tdep->fpregset = &sparc32nbsd_fpregset;
	tdep->sizeof_fpregset = 33 * 4;

	/* Make sure we can single-step "new" syscalls. */
	tdep->step_trap = sparcnbsd_step_trap;

	frame_unwind_append_unwinder (gdbarch, &sparc32nbsd_sigcontext_frame_unwind);

	set_solib_svr4_fetch_link_map_offsets
	(gdbarch, svr4_ilp32_fetch_link_map_offsets);
	}

	void _initialize_sparcnbsd_tdep ();
	void
	_initialize_sparcnbsd_tdep ()
	{
	gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_NETBSD,
	sparc32nbsd_init_abi);
	}