gdb/aarch64-linux-tdep.c - native_client/nacl-gdb - Git at Google

 /* Target-dependent code for GNU/Linux AArch64.

    Copyright (C) 2009-2013 Free Software Foundation, Inc.
    Contributed by ARM Ltd.

    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 "gdbarch.h"
 #include "glibc-tdep.h"
 #include "linux-tdep.h"
 #include "aarch64-tdep.h"
 #include "aarch64-linux-tdep.h"
 #include "osabi.h"
 #include "solib-svr4.h"
 #include "symtab.h"
 #include "tramp-frame.h"
 #include "trad-frame.h"

 #include "inferior.h"
 #include "regcache.h"
 #include "regset.h"

 /* The general-purpose regset consists of 31 X registers, plus SP, PC,
    and PSTATE registers, as defined in the AArch64 port of the Linux
    kernel.  */
 #define AARCH64_LINUX_SIZEOF_GREGSET  (34 * X_REGISTER_SIZE)

 /* The fp regset consists of 32 V registers, plus FPCR and FPSR which
    are 4 bytes wide each, and the whole structure is padded to 128 bit
    alignment.  */
 #define AARCH64_LINUX_SIZEOF_FPREGSET (33 * V_REGISTER_SIZE)

 /* Signal frame handling.

       +----------+  ^
       | saved lr |  |
    +->| saved fp |--+
    |  |          |
    |  |          |
    |  +----------+
    |  | saved lr |
    +--| saved fp |
    ^  |          |
    |  |          |
    |  +----------+
    ^  |          |
    |  | signal   |
    |  |          |
    |  | saved lr |-->interrupted_function_pc
    +--| saved fp |
    |  +----------+
    |  | saved lr |--> default_restorer (movz x8, NR_sys_rt_sigreturn; svc 0)
    +--| saved fp |<- FP
       |          |
       |          |<- SP
       +----------+

   On signal delivery, the kernel will create a signal handler stack
   frame and setup the return address in LR to point at restorer stub.
   The signal stack frame is defined by:

   struct rt_sigframe
   {
     siginfo_t info;
     struct ucontext uc;
   };

   typedef struct
   {
     ...                                    128 bytes
   } siginfo_t;

   The ucontext has the following form:
   struct ucontext
   {
     unsigned long uc_flags;
     struct ucontext *uc_link;
     stack_t uc_stack;
     sigset_t uc_sigmask;
     struct sigcontext uc_mcontext;
   };

   typedef struct sigaltstack
   {
     void *ss_sp;
     int ss_flags;
     size_t ss_size;
   } stack_t;

   struct sigcontext
   {
     unsigned long fault_address;
     unsigned long regs[31];
     unsigned long sp;		/ * 31 * /
     unsigned long pc;		/ * 32 * /
     unsigned long pstate;	/ * 33 * /
     __u8 __reserved[4096]
   };

   The restorer stub will always have the form:

   d28015a8        movz    x8, #0xad
   d4000001        svc     #0x0

   We detect signal frames by snooping the return code for the restorer
   instruction sequence.

   The handler then needs to recover the saved register set from
   ucontext.uc_mcontext.  */

 /* These magic numbers need to reflect the layout of the kernel
    defined struct rt_sigframe and ucontext.  */
 #define AARCH64_SIGCONTEXT_REG_SIZE             8
 #define AARCH64_RT_SIGFRAME_UCONTEXT_OFFSET     128
 #define AARCH64_UCONTEXT_SIGCONTEXT_OFFSET      176
 #define AARCH64_SIGCONTEXT_XO_OFFSET            8

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

 static void
 aarch64_linux_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);
   CORE_ADDR sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM);
   CORE_ADDR fp = get_frame_register_unsigned (this_frame, AARCH64_FP_REGNUM);
   CORE_ADDR sigcontext_addr =
     sp
     + AARCH64_RT_SIGFRAME_UCONTEXT_OFFSET
     + AARCH64_UCONTEXT_SIGCONTEXT_OFFSET;
   int i;

   for (i = 0; i < 31; i++)
     {
       trad_frame_set_reg_addr (this_cache,
 			       AARCH64_X0_REGNUM + i,
 			       sigcontext_addr + AARCH64_SIGCONTEXT_XO_OFFSET
 			       + i * AARCH64_SIGCONTEXT_REG_SIZE);
     }

   trad_frame_set_reg_addr (this_cache, AARCH64_FP_REGNUM, fp);
   trad_frame_set_reg_addr (this_cache, AARCH64_LR_REGNUM, fp + 8);
   trad_frame_set_reg_addr (this_cache, AARCH64_PC_REGNUM, fp + 8);

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

 static const struct tramp_frame aarch64_linux_rt_sigframe =
 {
   SIGTRAMP_FRAME,
   4,
   {
     /* movz x8, 0x8b (S=1,o=10,h=0,i=0x8b,r=8)
        Soo1 0010 1hhi iiii iiii iiii iiir rrrr  */
     {0xd2801168, -1},

     /* svc  0x0      (o=0, l=1)
        1101 0100 oooi iiii iiii iiii iii0 00ll  */
     {0xd4000001, -1},
     {TRAMP_SENTINEL_INSN, -1}
   },
   aarch64_linux_sigframe_init
 };

 /* Fill GDB's register array with the general-purpose register values
    in the buffer pointed by GREGS_BUF.  */

 void
 aarch64_linux_supply_gregset (struct regcache *regcache,
 			      const gdb_byte *gregs_buf)
 {
   int regno;

   for (regno = AARCH64_X0_REGNUM; regno <= AARCH64_CPSR_REGNUM; regno++)
     regcache_raw_supply (regcache, regno,
 			 gregs_buf + X_REGISTER_SIZE
 			 * (regno - AARCH64_X0_REGNUM));
 }

 /* The "supply_regset" function for the general-purpose register set.  */

 static void
 supply_gregset_from_core (const struct regset *regset,
 			  struct regcache *regcache,
 			  int regnum, const void *regbuf, size_t len)
 {
   aarch64_linux_supply_gregset (regcache, (const gdb_byte *) regbuf);
 }

 /* Fill GDB's register array with the floating-point register values
    in the buffer pointed by FPREGS_BUF.  */

 void
 aarch64_linux_supply_fpregset (struct regcache *regcache,
 			       const gdb_byte *fpregs_buf)
 {
   int regno;

   for (regno = AARCH64_V0_REGNUM; regno <= AARCH64_V31_REGNUM; regno++)
     regcache_raw_supply (regcache, regno,
 			 fpregs_buf + V_REGISTER_SIZE
 			 * (regno - AARCH64_V0_REGNUM));

   regcache_raw_supply (regcache, AARCH64_FPSR_REGNUM,
 		       fpregs_buf + V_REGISTER_SIZE * 32);
   regcache_raw_supply (regcache, AARCH64_FPCR_REGNUM,
 		       fpregs_buf + V_REGISTER_SIZE * 32 + 4);
 }

 /* The "supply_regset" function for the floating-point register set.  */

 static void
 supply_fpregset_from_core (const struct regset *regset,
 			   struct regcache *regcache,
 			   int regnum, const void *regbuf, size_t len)
 {
   aarch64_linux_supply_fpregset (regcache, (const gdb_byte *) regbuf);
 }

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

 static const struct regset *
 aarch64_linux_regset_from_core_section (struct gdbarch *gdbarch,
 					const char *sect_name,
 					size_t sect_size)
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

   if (strcmp (sect_name, ".reg") == 0
       && sect_size == AARCH64_LINUX_SIZEOF_GREGSET)
     {
       if (tdep->gregset == NULL)
 	tdep->gregset = regset_alloc (gdbarch, supply_gregset_from_core,
 				      NULL);
       return tdep->gregset;
     }

   if (strcmp (sect_name, ".reg2") == 0
       && sect_size == AARCH64_LINUX_SIZEOF_FPREGSET)
     {
       if (tdep->fpregset == NULL)
 	tdep->fpregset = regset_alloc (gdbarch, supply_fpregset_from_core,
 				       NULL);
       return tdep->fpregset;
     }
   return NULL;
 }

 static void
 aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 {
   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

   tdep->lowest_pc = 0x8000;

   linux_init_abi (info, gdbarch);

   set_solib_svr4_fetch_link_map_offsets (gdbarch,
 					 svr4_lp64_fetch_link_map_offsets);

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

   /* Shared library handling.  */
   set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);

   set_gdbarch_get_siginfo_type (gdbarch, linux_get_siginfo_type);
   tramp_frame_prepend_unwinder (gdbarch, &aarch64_linux_rt_sigframe);

   /* Enable longjmp.  */
   tdep->jb_pc = 11;

   set_gdbarch_regset_from_core_section (gdbarch,
 					aarch64_linux_regset_from_core_section);
 }

 /* Provide a prototype to silence -Wmissing-prototypes.  */
 extern initialize_file_ftype _initialize_aarch64_linux_tdep;

 void
 _initialize_aarch64_linux_tdep (void)
 {
   gdbarch_register_osabi (bfd_arch_aarch64, 0, GDB_OSABI_LINUX,
 			  aarch64_linux_init_abi);
 }
	/* Target-dependent code for GNU/Linux AArch64.

	Copyright (C) 2009-2013 Free Software Foundation, Inc.
	Contributed by ARM Ltd.

	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 "gdbarch.h"
	#include "glibc-tdep.h"
	#include "linux-tdep.h"
	#include "aarch64-tdep.h"
	#include "aarch64-linux-tdep.h"
	#include "osabi.h"
	#include "solib-svr4.h"
	#include "symtab.h"
	#include "tramp-frame.h"
	#include "trad-frame.h"

	#include "inferior.h"
	#include "regcache.h"
	#include "regset.h"

	/* The general-purpose regset consists of 31 X registers, plus SP, PC,
	and PSTATE registers, as defined in the AArch64 port of the Linux
	kernel. */
	#define AARCH64_LINUX_SIZEOF_GREGSET (34 * X_REGISTER_SIZE)

	/* The fp regset consists of 32 V registers, plus FPCR and FPSR which
	are 4 bytes wide each, and the whole structure is padded to 128 bit
	alignment. */
	#define AARCH64_LINUX_SIZEOF_FPREGSET (33 * V_REGISTER_SIZE)

	/* Signal frame handling.

	+----------+ ^
	\| saved lr \| \|
	+->\| saved fp \|--+
	\| \| \|
	\| \| \|
	\| +----------+
	\| \| saved lr \|
	+--\| saved fp \|
	^ \| \|
	\| \| \|
	\| +----------+
	^ \| \|
	\| \| signal \|
	\| \| \|
	\| \| saved lr \|-->interrupted_function_pc
	+--\| saved fp \|
	\| +----------+
	\| \| saved lr \|--> default_restorer (movz x8, NR_sys_rt_sigreturn; svc 0)
	+--\| saved fp \|<- FP
	\| \|
	\| \|<- SP
	+----------+

	On signal delivery, the kernel will create a signal handler stack
	frame and setup the return address in LR to point at restorer stub.
	The signal stack frame is defined by:

	struct rt_sigframe
	{
	siginfo_t info;
	struct ucontext uc;
	};

	typedef struct
	{
	... 128 bytes
	} siginfo_t;

	The ucontext has the following form:
	struct ucontext
	{
	unsigned long uc_flags;
	struct ucontext *uc_link;
	stack_t uc_stack;
	sigset_t uc_sigmask;
	struct sigcontext uc_mcontext;
	};

	typedef struct sigaltstack
	{
	void *ss_sp;
	int ss_flags;
	size_t ss_size;
	} stack_t;

	struct sigcontext
	{
	unsigned long fault_address;
	unsigned long regs[31];
	unsigned long sp; / * 31 * /
	unsigned long pc; / * 32 * /
	unsigned long pstate; / * 33 * /
	__u8 __reserved[4096]
	};

	The restorer stub will always have the form:

	d28015a8 movz x8, #0xad
	d4000001 svc #0x0

	We detect signal frames by snooping the return code for the restorer
	instruction sequence.

	The handler then needs to recover the saved register set from
	ucontext.uc_mcontext. */

	/* These magic numbers need to reflect the layout of the kernel
	defined struct rt_sigframe and ucontext. */
	#define AARCH64_SIGCONTEXT_REG_SIZE 8
	#define AARCH64_RT_SIGFRAME_UCONTEXT_OFFSET 128
	#define AARCH64_UCONTEXT_SIGCONTEXT_OFFSET 176
	#define AARCH64_SIGCONTEXT_XO_OFFSET 8

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

	static void
	aarch64_linux_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);
	CORE_ADDR sp = get_frame_register_unsigned (this_frame, AARCH64_SP_REGNUM);
	CORE_ADDR fp = get_frame_register_unsigned (this_frame, AARCH64_FP_REGNUM);
	CORE_ADDR sigcontext_addr =
	sp
	+ AARCH64_RT_SIGFRAME_UCONTEXT_OFFSET
	+ AARCH64_UCONTEXT_SIGCONTEXT_OFFSET;
	int i;

	for (i = 0; i < 31; i++)
	{
	trad_frame_set_reg_addr (this_cache,
	AARCH64_X0_REGNUM + i,
	sigcontext_addr + AARCH64_SIGCONTEXT_XO_OFFSET
	+ i * AARCH64_SIGCONTEXT_REG_SIZE);
	}

	trad_frame_set_reg_addr (this_cache, AARCH64_FP_REGNUM, fp);
	trad_frame_set_reg_addr (this_cache, AARCH64_LR_REGNUM, fp + 8);
	trad_frame_set_reg_addr (this_cache, AARCH64_PC_REGNUM, fp + 8);

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

	static const struct tramp_frame aarch64_linux_rt_sigframe =
	{
	SIGTRAMP_FRAME,
	4,
	{
	/* movz x8, 0x8b (S=1,o=10,h=0,i=0x8b,r=8)
	Soo1 0010 1hhi iiii iiii iiii iiir rrrr */
	{0xd2801168, -1},

	/* svc 0x0 (o=0, l=1)
	1101 0100 oooi iiii iiii iiii iii0 00ll */
	{0xd4000001, -1},
	{TRAMP_SENTINEL_INSN, -1}
	},
	aarch64_linux_sigframe_init
	};

	/* Fill GDB's register array with the general-purpose register values
	in the buffer pointed by GREGS_BUF. */

	void
	aarch64_linux_supply_gregset (struct regcache *regcache,
	const gdb_byte *gregs_buf)
	{
	int regno;

	for (regno = AARCH64_X0_REGNUM; regno <= AARCH64_CPSR_REGNUM; regno++)
	regcache_raw_supply (regcache, regno,
	gregs_buf + X_REGISTER_SIZE
	* (regno - AARCH64_X0_REGNUM));
	}

	/* The "supply_regset" function for the general-purpose register set. */

	static void
	supply_gregset_from_core (const struct regset *regset,
	struct regcache *regcache,
	int regnum, const void *regbuf, size_t len)
	{
	aarch64_linux_supply_gregset (regcache, (const gdb_byte *) regbuf);
	}

	/* Fill GDB's register array with the floating-point register values
	in the buffer pointed by FPREGS_BUF. */

	void
	aarch64_linux_supply_fpregset (struct regcache *regcache,
	const gdb_byte *fpregs_buf)
	{
	int regno;

	for (regno = AARCH64_V0_REGNUM; regno <= AARCH64_V31_REGNUM; regno++)
	regcache_raw_supply (regcache, regno,
	fpregs_buf + V_REGISTER_SIZE
	* (regno - AARCH64_V0_REGNUM));

	regcache_raw_supply (regcache, AARCH64_FPSR_REGNUM,
	fpregs_buf + V_REGISTER_SIZE * 32);
	regcache_raw_supply (regcache, AARCH64_FPCR_REGNUM,
	fpregs_buf + V_REGISTER_SIZE * 32 + 4);
	}

	/* The "supply_regset" function for the floating-point register set. */

	static void
	supply_fpregset_from_core (const struct regset *regset,
	struct regcache *regcache,
	int regnum, const void *regbuf, size_t len)
	{
	aarch64_linux_supply_fpregset (regcache, (const gdb_byte *) regbuf);
	}

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

	static const struct regset *
	aarch64_linux_regset_from_core_section (struct gdbarch *gdbarch,
	const char *sect_name,
	size_t sect_size)
	{
	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

	if (strcmp (sect_name, ".reg") == 0
	&& sect_size == AARCH64_LINUX_SIZEOF_GREGSET)
	{
	if (tdep->gregset == NULL)
	tdep->gregset = regset_alloc (gdbarch, supply_gregset_from_core,
	NULL);
	return tdep->gregset;
	}

	if (strcmp (sect_name, ".reg2") == 0
	&& sect_size == AARCH64_LINUX_SIZEOF_FPREGSET)
	{
	if (tdep->fpregset == NULL)
	tdep->fpregset = regset_alloc (gdbarch, supply_fpregset_from_core,
	NULL);
	return tdep->fpregset;
	}
	return NULL;
	}

	static void
	aarch64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
	{
	struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);

	tdep->lowest_pc = 0x8000;

	linux_init_abi (info, gdbarch);

	set_solib_svr4_fetch_link_map_offsets (gdbarch,
	svr4_lp64_fetch_link_map_offsets);

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

	/* Shared library handling. */
	set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target);

	set_gdbarch_get_siginfo_type (gdbarch, linux_get_siginfo_type);
	tramp_frame_prepend_unwinder (gdbarch, &aarch64_linux_rt_sigframe);

	/* Enable longjmp. */
	tdep->jb_pc = 11;

	set_gdbarch_regset_from_core_section (gdbarch,
	aarch64_linux_regset_from_core_section);
	}

	/* Provide a prototype to silence -Wmissing-prototypes. */
	extern initialize_file_ftype _initialize_aarch64_linux_tdep;

	void
	_initialize_aarch64_linux_tdep (void)
	{
	gdbarch_register_osabi (bfd_arch_aarch64, 0, GDB_OSABI_LINUX,
	aarch64_linux_init_abi);
	}