[deliverable/binutils-gdb.git] / gdb / gdbserver / linux-i386-ipa.c

/* GNU/Linux/x86 specific low level interface, for the in-process
   agent library for GDB.

   Copyright (C) 2010, 2011 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 "server.h"
#include <stdint.h>
#include <sys/mman.h>

/* GDB register numbers.  */

enum i386_gdb_regnum
{
  I386_EAX_REGNUM,		/* %eax */
  I386_ECX_REGNUM,		/* %ecx */
  I386_EDX_REGNUM,		/* %edx */
  I386_EBX_REGNUM,		/* %ebx */
  I386_ESP_REGNUM,		/* %esp */
  I386_EBP_REGNUM,		/* %ebp */
  I386_ESI_REGNUM,		/* %esi */
  I386_EDI_REGNUM,		/* %edi */
  I386_EIP_REGNUM,		/* %eip */
  I386_EFLAGS_REGNUM,		/* %eflags */
  I386_CS_REGNUM,		/* %cs */
  I386_SS_REGNUM,		/* %ss */
  I386_DS_REGNUM,		/* %ds */
  I386_ES_REGNUM,		/* %es */
  I386_FS_REGNUM,		/* %fs */
  I386_GS_REGNUM,		/* %gs */
  I386_ST0_REGNUM		/* %st(0) */
};

#define i386_num_regs 16

/* Defined in auto-generated file i386-linux.c.  */
void init_registers_i386_linux (void);

#define FT_CR_EAX 15
#define FT_CR_ECX 14
#define FT_CR_EDX 13
#define FT_CR_EBX 12
#define FT_CR_UESP 11
#define FT_CR_EBP 10
#define FT_CR_ESI 9
#define FT_CR_EDI 8
#define FT_CR_EIP 7
#define FT_CR_EFL 6
#define FT_CR_DS 5
#define FT_CR_ES 4
#define FT_CR_FS 3
#define FT_CR_GS 2
#define FT_CR_SS 1
#define FT_CR_CS 0

/* Mapping between the general-purpose registers in jump tracepoint
   format and GDB's register array layout.  */

static const int i386_ft_collect_regmap[] =
{
  FT_CR_EAX * 4, FT_CR_ECX * 4, FT_CR_EDX * 4, FT_CR_EBX * 4,
  FT_CR_UESP * 4, FT_CR_EBP * 4, FT_CR_ESI * 4, FT_CR_EDI * 4,
  FT_CR_EIP * 4, FT_CR_EFL * 4, FT_CR_CS * 4, FT_CR_SS * 4,
  FT_CR_DS * 4, FT_CR_ES * 4, FT_CR_FS * 4, FT_CR_GS * 4
};

void
supply_fast_tracepoint_registers (struct regcache *regcache,
				  const unsigned char *buf)
{
  int i;

  for (i = 0; i < i386_num_regs; i++)
    {
      int regval;

      if (i >= I386_CS_REGNUM && i <= I386_GS_REGNUM)
	regval = *(short *) (((char *) buf) + i386_ft_collect_regmap[i]);
      else
	regval = *(int *) (((char *) buf) + i386_ft_collect_regmap[i]);

      supply_register (regcache, i, &regval);
    }
}

ULONGEST __attribute__ ((visibility("default"), used))
gdb_agent_get_raw_reg (unsigned char *raw_regs, int regnum)
{
  /* This should maybe be allowed to return an error code, or perhaps
     better, have the emit_reg detect this, and emit a constant zero,
     or something.  */

  if (regnum > i386_num_regs)
    return 0;
  else if (regnum >= I386_CS_REGNUM && regnum <= I386_GS_REGNUM)
    return *(short *) (raw_regs + i386_ft_collect_regmap[regnum]);
  else
    return *(int *) (raw_regs + i386_ft_collect_regmap[regnum]);
}

#ifdef HAVE_UST

#include <ust/processor.h>

/* "struct registers" is the UST object type holding the registers at
   the time of the static tracepoint marker call.  This doesn't
   contain EIP, but we know what it must have been (the marker
   address).  */

#define ST_REGENTRY(REG)			\
  {						\
    offsetof (struct registers, REG),		\
    sizeof (((struct registers *) NULL)->REG)	\
  }

static struct
{
  int offset;
  int size;
} i386_st_collect_regmap[] =
  {
    ST_REGENTRY(eax),
    ST_REGENTRY(ecx),
    ST_REGENTRY(edx),
    ST_REGENTRY(ebx),
    ST_REGENTRY(esp),
    ST_REGENTRY(ebp),
    ST_REGENTRY(esi),
    ST_REGENTRY(edi),
    { -1, 0 }, /* eip */
    ST_REGENTRY(eflags),
    ST_REGENTRY(cs),
    ST_REGENTRY(ss),
  };

#define i386_NUM_ST_COLLECT_GREGS \
  (sizeof (i386_st_collect_regmap) / sizeof (i386_st_collect_regmap[0]))

void
supply_static_tracepoint_registers (struct regcache *regcache,
				    const unsigned char *buf,
				    CORE_ADDR pc)
{
  int i;
  unsigned int newpc = pc;

  supply_register (regcache, I386_EIP_REGNUM, &newpc);

  for (i = 0; i < i386_NUM_ST_COLLECT_GREGS; i++)
    if (i386_st_collect_regmap[i].offset != -1)
      {
	switch (i386_st_collect_regmap[i].size)
	  {
	  case 4:
	    supply_register (regcache, i,
			     ((char *) buf)
			     + i386_st_collect_regmap[i].offset);
	    break;
	  case 2:
	    {
	      unsigned long reg
		= * (short *) (((char *) buf)
			       + i386_st_collect_regmap[i].offset);
	      reg &= 0xffff;
	      supply_register (regcache, i, &reg);
	    }
	    break;
	  default:
	    internal_error (__FILE__, __LINE__, "unhandled register size: %d",
			    i386_st_collect_regmap[i].size);
	  }
      }
}

#endif /* HAVE_UST */


/* This is only needed because reg-i386-linux-lib.o references it.  We
   may use it proper at some point.  */
const char *gdbserver_xmltarget;

/* Attempt to allocate memory for trampolines in the first 64 KiB of
   memory to enable smaller jump patches.  */

static void
initialize_fast_tracepoint_trampoline_buffer (void)
{
  const CORE_ADDR buffer_end = 64 * 1024;
  /* Ensure that the buffer will be at least 1 KiB in size, which is
     enough space for over 200 fast tracepoints.  */
  const int min_buffer_size = 1024;
  char buf[IPA_BUFSIZ];
  CORE_ADDR mmap_min_addr = buffer_end + 1;
  ULONGEST buffer_size;
  FILE *f = fopen ("/proc/sys/vm/mmap_min_addr", "r");

  if (!f)
    {    
      snprintf (buf, sizeof (buf), "mmap_min_addr open failed: %s",
		strerror (errno));
      set_trampoline_buffer_space (0, 0, buf);
      return;
    }

  if (fgets (buf, IPA_BUFSIZ, f))
    sscanf (buf, "%llu", &mmap_min_addr);
      
  fclose (f);
      
  buffer_size = buffer_end - mmap_min_addr;

  if (buffer_size >= min_buffer_size)
    {
      if (mmap ((void *) (uintptr_t) mmap_min_addr, buffer_size,
		PROT_READ | PROT_EXEC | PROT_WRITE,
		MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS,
		-1, 0)
	  != MAP_FAILED)
	set_trampoline_buffer_space (mmap_min_addr, buffer_end, NULL);
      else
	{
	  snprintf (buf, IPA_BUFSIZ, "low-64K-buffer mmap() failed: %s",
		    strerror (errno));
	  set_trampoline_buffer_space (0, 0, buf);
	}
    }
  else
    {
      snprintf (buf, IPA_BUFSIZ, "mmap_min_addr is %d, must be %d or less",
		(int) mmap_min_addr, (int) buffer_end - min_buffer_size);
      set_trampoline_buffer_space (0, 0, buf);
    }
}

void
initialize_low_tracepoint (void)
{
  init_registers_i386_linux ();
  initialize_fast_tracepoint_trampoline_buffer ();
}
Commit	Line	Data
fa593d66 PA	1	/* GNU/Linux/x86 specific low level interface, for the in-process
	2	agent library for GDB.
	3
7b6bb8da	4	Copyright (C) 2010, 2011 Free Software Foundation, Inc.
fa593d66 PA	5
	6	This file is part of GDB.
	7
	8	This program is free software; you can redistribute it and/or modify
	9	it under the terms of the GNU General Public License as published by
	10	the Free Software Foundation; either version 3 of the License, or
	11	(at your option) any later version.
	12
	13	This program is distributed in the hope that it will be useful,
	14	but WITHOUT ANY WARRANTY; without even the implied warranty of
	15	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	16	GNU General Public License for more details.
	17
	18	You should have received a copy of the GNU General Public License
	19	along with this program. If not, see <http://www.gnu.org/licenses/>. */
	20
	21	#include "server.h"
405f8e94 SS	22	#include <stdint.h>
405f8e94 SS	23	#include <sys/mman.h>
fa593d66 PA	24
	25	/* GDB register numbers. */
	26
	27	enum i386_gdb_regnum
	28	{
	29	I386_EAX_REGNUM, /* %eax */
	30	I386_ECX_REGNUM, /* %ecx */
	31	I386_EDX_REGNUM, /* %edx */
	32	I386_EBX_REGNUM, /* %ebx */
	33	I386_ESP_REGNUM, /* %esp */
	34	I386_EBP_REGNUM, /* %ebp */
	35	I386_ESI_REGNUM, /* %esi */
	36	I386_EDI_REGNUM, /* %edi */
	37	I386_EIP_REGNUM, /* %eip */
	38	I386_EFLAGS_REGNUM, /* %eflags */
	39	I386_CS_REGNUM, /* %cs */
	40	I386_SS_REGNUM, /* %ss */
	41	I386_DS_REGNUM, /* %ds */
	42	I386_ES_REGNUM, /* %es */
	43	I386_FS_REGNUM, /* %fs */
	44	I386_GS_REGNUM, /* %gs */
	45	I386_ST0_REGNUM /* %st(0) */
	46	};
	47
	48	#define i386_num_regs 16
	49
	50	/* Defined in auto-generated file i386-linux.c. */
	51	void init_registers_i386_linux (void);
	52
	53	#define FT_CR_EAX 15
	54	#define FT_CR_ECX 14
	55	#define FT_CR_EDX 13
	56	#define FT_CR_EBX 12
	57	#define FT_CR_UESP 11
	58	#define FT_CR_EBP 10
	59	#define FT_CR_ESI 9
	60	#define FT_CR_EDI 8
	61	#define FT_CR_EIP 7
	62	#define FT_CR_EFL 6
	63	#define FT_CR_DS 5
	64	#define FT_CR_ES 4
	65	#define FT_CR_FS 3
	66	#define FT_CR_GS 2
	67	#define FT_CR_SS 1
	68	#define FT_CR_CS 0
	69
	70	/* Mapping between the general-purpose registers in jump tracepoint
	71	format and GDB's register array layout. */
	72
	73	static const int i386_ft_collect_regmap[] =
	74	{
	75	FT_CR_EAX * 4, FT_CR_ECX * 4, FT_CR_EDX * 4, FT_CR_EBX * 4,
	76	FT_CR_UESP * 4, FT_CR_EBP * 4, FT_CR_ESI * 4, FT_CR_EDI * 4,
	77	FT_CR_EIP * 4, FT_CR_EFL * 4, FT_CR_CS * 4, FT_CR_SS * 4,
	78	FT_CR_DS * 4, FT_CR_ES * 4, FT_CR_FS * 4, FT_CR_GS * 4
	79	};
	80
	81	void
	82	supply_fast_tracepoint_registers (struct regcache *regcache,
	83	const unsigned char *buf)
	84	{
	85	int i;
	86
	87	for (i = 0; i < i386_num_regs; i++)
88	{
89	int regval;
90
91	if (i >= I386_CS_REGNUM && i <= I386_GS_REGNUM)
92	regval = (short ) (((char *) buf) + i386_ft_collect_regmap[i]);
93	else
94	regval = (int ) (((char *) buf) + i386_ft_collect_regmap[i]);
95
96	supply_register (regcache, i, &regval);
97	}
98	}
99
6a271cae PA	100	ULONGEST __attribute__ ((visibility("default"), used))
	101	gdb_agent_get_raw_reg (unsigned char *raw_regs, int regnum)
	102	{
	103	/* This should maybe be allowed to return an error code, or perhaps
	104	better, have the emit_reg detect this, and emit a constant zero,
	105	or something. */
	106
	107	if (regnum > i386_num_regs)
	108	return 0;
	109	else if (regnum >= I386_CS_REGNUM && regnum <= I386_GS_REGNUM)
	110	return (short ) (raw_regs + i386_ft_collect_regmap[regnum]);
	111	else
	112	return (int ) (raw_regs + i386_ft_collect_regmap[regnum]);
	113	}
	114
0fb4aa4b PA	115	#ifdef HAVE_UST
	116
	117	#include <ust/processor.h>
	118
	119	/* "struct registers" is the UST object type holding the registers at
	120	the time of the static tracepoint marker call. This doesn't
	121	contain EIP, but we know what it must have been (the marker
	122	address). */
	123
	124	#define ST_REGENTRY(REG) \
	125	{ \
	126	offsetof (struct registers, REG), \
	127	sizeof (((struct registers *) NULL)->REG) \
	128	}
	129
	130	static struct
	131	{
	132	int offset;
	133	int size;
	134	} i386_st_collect_regmap[] =
	135	{
	136	ST_REGENTRY(eax),
	137	ST_REGENTRY(ecx),
	138	ST_REGENTRY(edx),
	139	ST_REGENTRY(ebx),
	140	ST_REGENTRY(esp),
	141	ST_REGENTRY(ebp),
	142	ST_REGENTRY(esi),
	143	ST_REGENTRY(edi),
	144	{ -1, 0 }, /* eip */
	145	ST_REGENTRY(eflags),
	146	ST_REGENTRY(cs),
	147	ST_REGENTRY(ss),
	148	};
	149
	150	#define i386_NUM_ST_COLLECT_GREGS \
	151	(sizeof (i386_st_collect_regmap) / sizeof (i386_st_collect_regmap[0]))
	152
	153	void
	154	supply_static_tracepoint_registers (struct regcache *regcache,
	155	const unsigned char *buf,
	156	CORE_ADDR pc)
	157	{
	158	int i;
	159	unsigned int newpc = pc;
	160
	161	supply_register (regcache, I386_EIP_REGNUM, &newpc);
	162
	163	for (i = 0; i < i386_NUM_ST_COLLECT_GREGS; i++)
	164	if (i386_st_collect_regmap[i].offset != -1)
	165	{
	166	switch (i386_st_collect_regmap[i].size)
	167	{
	168	case 4:
	169	supply_register (regcache, i,
	170	((char *) buf)
	171	+ i386_st_collect_regmap[i].offset);
	172	break;
	173	case 2:
	174	{
	175	unsigned long reg
	176	= * (short ) (((char ) buf)
	177	+ i386_st_collect_regmap[i].offset);
	178	reg &= 0xffff;
179	supply_register (regcache, i, &reg);
180	}
181	break;
182	default:
b481f9e0	183	internal_error (__FILE__, __LINE__, "unhandled register size: %d",
0fb4aa4b PA	184	i386_st_collect_regmap[i].size);
	185	}
	186	}
	187	}
	188
	189	#endif /* HAVE_UST */
	190
	191
fa593d66 PA	192	/* This is only needed because reg-i386-linux-lib.o references it. We
	193	may use it proper at some point. */
	194	const char *gdbserver_xmltarget;
	195
405f8e94 SS	196	/* Attempt to allocate memory for trampolines in the first 64 KiB of
	197	memory to enable smaller jump patches. */
	198
	199	static void
	200	initialize_fast_tracepoint_trampoline_buffer (void)
	201	{
	202	const CORE_ADDR buffer_end = 64 * 1024;
	203	/* Ensure that the buffer will be at least 1 KiB in size, which is
	204	enough space for over 200 fast tracepoints. */
	205	const int min_buffer_size = 1024;
	206	char buf[IPA_BUFSIZ];
	207	CORE_ADDR mmap_min_addr = buffer_end + 1;
	208	ULONGEST buffer_size;
	209	FILE *f = fopen ("/proc/sys/vm/mmap_min_addr", "r");
	210
	211	if (!f)
	212	{
	213	snprintf (buf, sizeof (buf), "mmap_min_addr open failed: %s",
	214	strerror (errno));
	215	set_trampoline_buffer_space (0, 0, buf);
	216	return;
	217	}
	218
	219	if (fgets (buf, IPA_BUFSIZ, f))
	220	sscanf (buf, "%llu", &mmap_min_addr);
	221
	222	fclose (f);
	223
	224	buffer_size = buffer_end - mmap_min_addr;
	225
	226	if (buffer_size >= min_buffer_size)
	227	{
	228	if (mmap ((void *) (uintptr_t) mmap_min_addr, buffer_size,
	229	PROT_READ \| PROT_EXEC \| PROT_WRITE,
	230	MAP_FIXED \| MAP_PRIVATE \| MAP_ANONYMOUS,
	231	-1, 0)
	232	!= MAP_FAILED)
	233	set_trampoline_buffer_space (mmap_min_addr, buffer_end, NULL);
	234	else
	235	{
	236	snprintf (buf, IPA_BUFSIZ, "low-64K-buffer mmap() failed: %s",
	237	strerror (errno));
	238	set_trampoline_buffer_space (0, 0, buf);
	239	}
	240	}
	241	else
	242	{
	243	snprintf (buf, IPA_BUFSIZ, "mmap_min_addr is %d, must be %d or less",
	244	(int) mmap_min_addr, (int) buffer_end - min_buffer_size);
	245	set_trampoline_buffer_space (0, 0, buf);
	246	}
	247	}
	248
fa593d66 PA	249	void
	250	initialize_low_tracepoint (void)
	251	{
	252	init_registers_i386_linux ();
405f8e94	253	initialize_fast_tracepoint_trampoline_buffer ();
fa593d66	254	}