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

 /* Target-dependent code for GNU/Linux SPARC.

    Copyright (C) 2003, 2004, 2005, 2007 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 "dwarf2-frame.h"
 #include "frame.h"
 #include "frame-unwind.h"
 #include "gdbtypes.h"
 #include "regset.h"
 #include "gdbarch.h"
 #include "gdbcore.h"
 #include "osabi.h"
 #include "regcache.h"
 #include "solib-svr4.h"
 #include "symtab.h"
 #include "trad-frame.h"
 #include "tramp-frame.h"

 #include "sparc-tdep.h"

 /* Signal trampoline support.  */

 static void sparc32_linux_sigframe_init (const struct tramp_frame *self,
 					 struct frame_info *next_frame,
 					 struct trad_frame_cache *this_cache,
 					 CORE_ADDR func);

 /* GNU/Linux has two flavors of signals.  Normal signal handlers, and
    "realtime" (RT) signals.  The RT signals can provide additional
    information to the signal handler if the SA_SIGINFO flag is set
    when establishing a signal handler using `sigaction'.  It is not
    unlikely that future versions of GNU/Linux will support SA_SIGINFO
    for normal signals too.  */

 /* When the sparc Linux kernel calls a signal handler and the
    SA_RESTORER flag isn't set, the return address points to a bit of
    code on the stack.  This code checks whether the PC appears to be
    within this bit of code.

    The instruction sequence for normal signals is encoded below.
    Checking for the code sequence should be somewhat reliable, because
    the effect is to call the system call sigreturn.  This is unlikely
    to occur anywhere other than a signal trampoline.  */

 static const struct tramp_frame sparc32_linux_sigframe =
 {
   SIGTRAMP_FRAME,
   4,
   {
     { 0x821020d8, -1 },		/* mov __NR_sugreturn, %g1 */
     { 0x91d02010, -1 },		/* ta  0x10 */
     { TRAMP_SENTINEL_INSN, -1 }
   },
   sparc32_linux_sigframe_init
 };

 /* The instruction sequence for RT signals is slightly different.  The
    effect is to call the system call rt_sigreturn.  */

 static const struct tramp_frame sparc32_linux_rt_sigframe =
 {
   SIGTRAMP_FRAME,
   4,
   {
     { 0x82102065, -1 },		/* mov __NR_rt_sigreturn, %g1 */
     { 0x91d02010, -1 },		/* ta  0x10 */
     { TRAMP_SENTINEL_INSN, -1 }
   },
   sparc32_linux_sigframe_init
 };

 static void
 sparc32_linux_sigframe_init (const struct tramp_frame *self,
 			     struct frame_info *next_frame,
 			     struct trad_frame_cache *this_cache,
 			     CORE_ADDR func)
 {
   CORE_ADDR base, addr, sp_addr;
   int regnum;

   base = frame_unwind_register_unsigned (next_frame, SPARC_O1_REGNUM);
   if (self == &sparc32_linux_rt_sigframe)
     base += 128;

   /* Offsets from <bits/sigcontext.h>.  */

   trad_frame_set_reg_addr (this_cache, SPARC32_PSR_REGNUM, base + 0);
   trad_frame_set_reg_addr (this_cache, SPARC32_PC_REGNUM, base + 4);
   trad_frame_set_reg_addr (this_cache, SPARC32_NPC_REGNUM, base + 8);
   trad_frame_set_reg_addr (this_cache, SPARC32_Y_REGNUM, base + 12);

   /* Since %g0 is always zero, keep the identity encoding.  */
   addr = base + 20;
   sp_addr = base + 16 + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 4);
   for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
     {
       trad_frame_set_reg_addr (this_cache, regnum, addr);
       addr += 4;
     }

   base = frame_unwind_register_unsigned (next_frame, SPARC_SP_REGNUM);
   addr = get_frame_memory_unsigned (next_frame, sp_addr, 4);

   for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
     {
       trad_frame_set_reg_addr (this_cache, regnum, addr);
       addr += 4;
     }
   trad_frame_set_id (this_cache, frame_id_build (base, func));
 }

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

 static CORE_ADDR
 sparc32_linux_step_trap (struct frame_info *frame, unsigned long insn)
 {
   if (insn == 0x91d02010)
     {
       ULONGEST sc_num = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);

       /* __NR_rt_sigreturn is 101 and __NR_sigreturn is 216  */
       if (sc_num == 101 || sc_num == 216)
 	{
 	  ULONGEST sp, pc_offset;

 	  sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM);

 	  /* The kernel puts the sigreturn registers on the stack,
 	     and this is where the signal unwinding state is take from
 	     when returning from a signal.

 	     For __NR_sigreturn, this register area sits 96 bytes from
 	     the base of the stack.  The saved PC sits 4 bytes into the
 	     sigreturn register save area.

 	     For __NR_rt_sigreturn a siginfo_t, which is 128 bytes, sits
 	     right before the sigreturn register save area.  */

 	  pc_offset = 96 + 4;
 	  if (sc_num == 101)
 	    pc_offset += 128;

 	  return read_memory_unsigned_integer (sp + pc_offset, 4);
 	}
     }

   return 0;
 }


 const struct sparc_gregset sparc32_linux_core_gregset =
 {
   32 * 4,			/* %psr */
   33 * 4,			/* %pc */
   34 * 4,			/* %npc */
   35 * 4,			/* %y */
   -1,				/* %wim */
   -1,				/* %tbr */
   1 * 4,			/* %g1 */
   16 * 4,			/* %l0 */
   4,				/* y size */
 };


 static void
 sparc32_linux_supply_core_gregset (const struct regset *regset,
 				   struct regcache *regcache,
 				   int regnum, const void *gregs, size_t len)
 {
   sparc32_supply_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
 }

 static void
 sparc32_linux_collect_core_gregset (const struct regset *regset,
 				    const struct regcache *regcache,
 				    int regnum, void *gregs, size_t len)
 {
   sparc32_collect_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
 }

 static void
 sparc32_linux_supply_core_fpregset (const struct regset *regset,
 				    struct regcache *regcache,
 				    int regnum, const void *fpregs, size_t len)
 {
   sparc32_supply_fpregset (regcache, regnum, fpregs);
 }

 static void
 sparc32_linux_collect_core_fpregset (const struct regset *regset,
 				     const struct regcache *regcache,
 				     int regnum, void *fpregs, size_t len)
 {
   sparc32_collect_fpregset (regcache, regnum, fpregs);
 }


 static void
 sparc32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

   tdep->gregset = regset_alloc (gdbarch, sparc32_linux_supply_core_gregset,
 				sparc32_linux_collect_core_gregset);
   tdep->sizeof_gregset = 152;

   tdep->fpregset = regset_alloc (gdbarch, sparc32_linux_supply_core_fpregset,
 				 sparc32_linux_collect_core_fpregset);
   tdep->sizeof_fpregset = 396;

   tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_sigframe);
   tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_rt_sigframe);

   /* GNU/Linux has SVR4-style shared libraries...  */
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
   set_solib_svr4_fetch_link_map_offsets
     (gdbarch, svr4_ilp32_fetch_link_map_offsets);

   /* ...which means that we need some special handling when doing
      prologue analysis.  */
   tdep->plt_entry_size = 12;

   /* GNU/Linux 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);

   /* Enable TLS support.  */
   set_gdbarch_fetch_tls_load_module_address (gdbarch,
                                              svr4_fetch_objfile_link_map);

   /* Make sure we can single-step over signal return system calls.  */
   tdep->step_trap = sparc32_linux_step_trap;

   /* Hook in the DWARF CFI frame unwinder.  */
   frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer);
 }

 /* Provide a prototype to silence -Wmissing-prototypes.  */
 extern void _initialize_sparc_linux_tdep (void);

 void
 _initialize_sparc_linux_tdep (void)
 {
   gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_LINUX,
 			  sparc32_linux_init_abi);
 }
	/* Target-dependent code for GNU/Linux SPARC.

	Copyright (C) 2003, 2004, 2005, 2007 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 "dwarf2-frame.h"
	#include "frame.h"
	#include "frame-unwind.h"
	#include "gdbtypes.h"
	#include "regset.h"
	#include "gdbarch.h"
	#include "gdbcore.h"
	#include "osabi.h"
	#include "regcache.h"
	#include "solib-svr4.h"
	#include "symtab.h"
	#include "trad-frame.h"
	#include "tramp-frame.h"

	#include "sparc-tdep.h"

	/* Signal trampoline support. */

	static void sparc32_linux_sigframe_init (const struct tramp_frame *self,
	struct frame_info *next_frame,
	struct trad_frame_cache *this_cache,
	CORE_ADDR func);

	/* GNU/Linux has two flavors of signals. Normal signal handlers, and
	"realtime" (RT) signals. The RT signals can provide additional
	information to the signal handler if the SA_SIGINFO flag is set
	when establishing a signal handler using `sigaction'. It is not
	unlikely that future versions of GNU/Linux will support SA_SIGINFO
	for normal signals too. */

	/* When the sparc Linux kernel calls a signal handler and the
	SA_RESTORER flag isn't set, the return address points to a bit of
	code on the stack. This code checks whether the PC appears to be
	within this bit of code.

	The instruction sequence for normal signals is encoded below.
	Checking for the code sequence should be somewhat reliable, because
	the effect is to call the system call sigreturn. This is unlikely
	to occur anywhere other than a signal trampoline. */

	static const struct tramp_frame sparc32_linux_sigframe =
	{
	SIGTRAMP_FRAME,
	4,
	{
	{ 0x821020d8, -1 }, /* mov __NR_sugreturn, %g1 */
	{ 0x91d02010, -1 }, /* ta 0x10 */
	{ TRAMP_SENTINEL_INSN, -1 }
	},
	sparc32_linux_sigframe_init
	};

	/* The instruction sequence for RT signals is slightly different. The
	effect is to call the system call rt_sigreturn. */

	static const struct tramp_frame sparc32_linux_rt_sigframe =
	{
	SIGTRAMP_FRAME,
	4,
	{
	{ 0x82102065, -1 }, /* mov __NR_rt_sigreturn, %g1 */
	{ 0x91d02010, -1 }, /* ta 0x10 */
	{ TRAMP_SENTINEL_INSN, -1 }
	},
	sparc32_linux_sigframe_init
	};

	static void
	sparc32_linux_sigframe_init (const struct tramp_frame *self,
	struct frame_info *next_frame,
	struct trad_frame_cache *this_cache,
	CORE_ADDR func)
	{
	CORE_ADDR base, addr, sp_addr;
	int regnum;

	base = frame_unwind_register_unsigned (next_frame, SPARC_O1_REGNUM);
	if (self == &sparc32_linux_rt_sigframe)
	base += 128;

	/* Offsets from <bits/sigcontext.h>. */

	trad_frame_set_reg_addr (this_cache, SPARC32_PSR_REGNUM, base + 0);
	trad_frame_set_reg_addr (this_cache, SPARC32_PC_REGNUM, base + 4);
	trad_frame_set_reg_addr (this_cache, SPARC32_NPC_REGNUM, base + 8);
	trad_frame_set_reg_addr (this_cache, SPARC32_Y_REGNUM, base + 12);

	/* Since %g0 is always zero, keep the identity encoding. */
	addr = base + 20;
	sp_addr = base + 16 + ((SPARC_SP_REGNUM - SPARC_G0_REGNUM) * 4);
	for (regnum = SPARC_G1_REGNUM; regnum <= SPARC_O7_REGNUM; regnum++)
	{
	trad_frame_set_reg_addr (this_cache, regnum, addr);
	addr += 4;
	}

	base = frame_unwind_register_unsigned (next_frame, SPARC_SP_REGNUM);
	addr = get_frame_memory_unsigned (next_frame, sp_addr, 4);

	for (regnum = SPARC_L0_REGNUM; regnum <= SPARC_I7_REGNUM; regnum++)
	{
	trad_frame_set_reg_addr (this_cache, regnum, addr);
	addr += 4;
	}
	trad_frame_set_id (this_cache, frame_id_build (base, func));
	}

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

	static CORE_ADDR
	sparc32_linux_step_trap (struct frame_info *frame, unsigned long insn)
	{
	if (insn == 0x91d02010)
	{
	ULONGEST sc_num = get_frame_register_unsigned (frame, SPARC_G1_REGNUM);

	/* __NR_rt_sigreturn is 101 and __NR_sigreturn is 216 */
	if (sc_num == 101 \|\| sc_num == 216)
	{
	ULONGEST sp, pc_offset;

	sp = get_frame_register_unsigned (frame, SPARC_SP_REGNUM);

	/* The kernel puts the sigreturn registers on the stack,
	and this is where the signal unwinding state is take from
	when returning from a signal.

	For __NR_sigreturn, this register area sits 96 bytes from
	the base of the stack. The saved PC sits 4 bytes into the
	sigreturn register save area.

	For __NR_rt_sigreturn a siginfo_t, which is 128 bytes, sits
	right before the sigreturn register save area. */

	pc_offset = 96 + 4;
	if (sc_num == 101)
	pc_offset += 128;

	return read_memory_unsigned_integer (sp + pc_offset, 4);
	}
	}

	return 0;
	}


	const struct sparc_gregset sparc32_linux_core_gregset =
	{
	32 * 4, /* %psr */
	33 * 4, /* %pc */
	34 * 4, /* %npc */
	35 * 4, /* %y */
	-1, /* %wim */
	-1, /* %tbr */
	1 * 4, /* %g1 */
	16 * 4, /* %l0 */
	4, /* y size */
	};


	static void
	sparc32_linux_supply_core_gregset (const struct regset *regset,
	struct regcache *regcache,
	int regnum, const void *gregs, size_t len)
	{
	sparc32_supply_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
	}

	static void
	sparc32_linux_collect_core_gregset (const struct regset *regset,
	const struct regcache *regcache,
	int regnum, void *gregs, size_t len)
	{
	sparc32_collect_gregset (&sparc32_linux_core_gregset, regcache, regnum, gregs);
	}

	static void
	sparc32_linux_supply_core_fpregset (const struct regset *regset,
	struct regcache *regcache,
	int regnum, const void *fpregs, size_t len)
	{
	sparc32_supply_fpregset (regcache, regnum, fpregs);
	}

	static void
	sparc32_linux_collect_core_fpregset (const struct regset *regset,
	const struct regcache *regcache,
	int regnum, void *fpregs, size_t len)
	{
	sparc32_collect_fpregset (regcache, regnum, fpregs);
	}



	static void
	sparc32_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	{
	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

	tdep->gregset = regset_alloc (gdbarch, sparc32_linux_supply_core_gregset,
	sparc32_linux_collect_core_gregset);
	tdep->sizeof_gregset = 152;

	tdep->fpregset = regset_alloc (gdbarch, sparc32_linux_supply_core_fpregset,
	sparc32_linux_collect_core_fpregset);
	tdep->sizeof_fpregset = 396;

	tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_sigframe);
	tramp_frame_prepend_unwinder (gdbarch, &sparc32_linux_rt_sigframe);

	/* GNU/Linux has SVR4-style shared libraries... */
	set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);
	set_solib_svr4_fetch_link_map_offsets
	(gdbarch, svr4_ilp32_fetch_link_map_offsets);

	/* ...which means that we need some special handling when doing
	prologue analysis. */
	tdep->plt_entry_size = 12;

	/* GNU/Linux 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);

	/* Enable TLS support. */
	set_gdbarch_fetch_tls_load_module_address (gdbarch,
	svr4_fetch_objfile_link_map);

	/* Make sure we can single-step over signal return system calls. */
	tdep->step_trap = sparc32_linux_step_trap;

	/* Hook in the DWARF CFI frame unwinder. */
	frame_unwind_append_sniffer (gdbarch, dwarf2_frame_sniffer);
	}

	/* Provide a prototype to silence -Wmissing-prototypes. */
	extern void _initialize_sparc_linux_tdep (void);

	void
	_initialize_sparc_linux_tdep (void)
	{
	gdbarch_register_osabi (bfd_arch_sparc, 0, GDB_OSABI_LINUX,
	sparc32_linux_init_abi);
	}