gdb/auxv.c - binutils-gdb - Git at Google

 /* Auxiliary vector support for GDB, the GNU debugger.

    Copyright (C) 2004, 2005, 2006, 2007, 2008 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 "target.h"
 #include "gdbtypes.h"
 #include "command.h"
 #include "inferior.h"
 #include "valprint.h"
 #include "gdb_assert.h"

 #include "auxv.h"
 #include "elf/common.h"

 #include <unistd.h>
 #include <fcntl.h>


 /* This function is called like a to_xfer_partial hook,
    but must be called with TARGET_OBJECT_AUXV.
    It handles access via /proc/PID/auxv, which is the common method.
    This function is appropriate for doing:
 	   #define NATIVE_XFER_AUXV	procfs_xfer_auxv
    for a native target that uses inftarg.c's child_xfer_partial hook.  */

 LONGEST
 procfs_xfer_auxv (struct target_ops *ops,
 		  int /* enum target_object */ object,
 		  const char *annex,
 		  gdb_byte *readbuf,
 		  const gdb_byte *writebuf,
 		  ULONGEST offset,
 		  LONGEST len)
 {
   char *pathname;
   int fd;
   LONGEST n;

   gdb_assert (object == TARGET_OBJECT_AUXV);
   gdb_assert (readbuf || writebuf);

   pathname = xstrprintf ("/proc/%d/auxv", PIDGET (inferior_ptid));
   fd = open (pathname, writebuf != NULL ? O_WRONLY : O_RDONLY);
   xfree (pathname);
   if (fd < 0)
     return -1;

   if (offset != (ULONGEST) 0
       && lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
     n = -1;
   else if (readbuf != NULL)
     n = read (fd, readbuf, len);
   else
     n = write (fd, writebuf, len);

   (void) close (fd);

   return n;
 }

 /* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
    Return 0 if *READPTR is already at the end of the buffer.
    Return -1 if there is insufficient buffer for a whole entry.
    Return 1 if an entry was read into *TYPEP and *VALP.  */
 int
 default_auxv_parse (struct target_ops *ops, gdb_byte **readptr,
 		   gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
 {
   const int sizeof_auxv_field = gdbarch_ptr_bit (target_gdbarch)
 				/ TARGET_CHAR_BIT;
   gdb_byte *ptr = *readptr;

   if (endptr == ptr)
     return 0;

   if (endptr - ptr < sizeof_auxv_field * 2)
     return -1;

   *typep = extract_unsigned_integer (ptr, sizeof_auxv_field);
   ptr += sizeof_auxv_field;
   *valp = extract_unsigned_integer (ptr, sizeof_auxv_field);
   ptr += sizeof_auxv_field;

   *readptr = ptr;
   return 1;
 }

 /* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
    Return 0 if *READPTR is already at the end of the buffer.
    Return -1 if there is insufficient buffer for a whole entry.
    Return 1 if an entry was read into *TYPEP and *VALP.  */
 int
 target_auxv_parse (struct target_ops *ops, gdb_byte **readptr,
                   gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
 {
   struct target_ops *t;
   for (t = ops; t != NULL; t = t->beneath)
     if (t->to_auxv_parse != NULL)
       return t->to_auxv_parse (t, readptr, endptr, typep, valp);

   return default_auxv_parse (ops, readptr, endptr, typep, valp);
 }

 /* Extract the auxiliary vector entry with a_type matching MATCH.
    Return zero if no such entry was found, or -1 if there was
    an error getting the information.  On success, return 1 after
    storing the entry's value field in *VALP.  */
 int
 target_auxv_search (struct target_ops *ops, CORE_ADDR match, CORE_ADDR *valp)
 {
   CORE_ADDR type, val;
   gdb_byte *data;
   LONGEST n = target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL, &data);
   gdb_byte *ptr = data;
   int ents = 0;

   if (n <= 0)
     return n;

   while (1)
     switch (target_auxv_parse (ops, &ptr, data + n, &type, &val))
       {
       case 1:			/* Here's an entry, check it.  */
 	if (type == match)
 	  {
 	    xfree (data);
 	    *valp = val;
 	    return 1;
 	  }
 	break;
       case 0:			/* End of the vector.  */
 	xfree (data);
 	return 0;
       default:			/* Bogosity.  */
 	xfree (data);
 	return -1;
       }

   /*NOTREACHED*/
 }


 /* Print the contents of the target's AUXV on the specified file. */
 int
 fprint_target_auxv (struct ui_file *file, struct target_ops *ops)
 {
   CORE_ADDR type, val;
   gdb_byte *data;
   LONGEST len = target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL,
 				   &data);
   gdb_byte *ptr = data;
   int ents = 0;

   if (len <= 0)
     return len;

   while (target_auxv_parse (ops, &ptr, data + len, &type, &val) > 0)
     {
       const char *name = "???";
       const char *description = "";
       enum { dec, hex, str } flavor = hex;

       switch (type)
 	{
 #define TAG(tag, text, kind) \
 	case tag: name = #tag; description = text; flavor = kind; break
 	  TAG (AT_NULL, _("End of vector"), hex);
 	  TAG (AT_IGNORE, _("Entry should be ignored"), hex);
 	  TAG (AT_EXECFD, _("File descriptor of program"), dec);
 	  TAG (AT_PHDR, _("Program headers for program"), hex);
 	  TAG (AT_PHENT, _("Size of program header entry"), dec);
 	  TAG (AT_PHNUM, _("Number of program headers"), dec);
 	  TAG (AT_PAGESZ, _("System page size"), dec);
 	  TAG (AT_BASE, _("Base address of interpreter"), hex);
 	  TAG (AT_FLAGS, _("Flags"), hex);
 	  TAG (AT_ENTRY, _("Entry point of program"), hex);
 	  TAG (AT_NOTELF, _("Program is not ELF"), dec);
 	  TAG (AT_UID, _("Real user ID"), dec);
 	  TAG (AT_EUID, _("Effective user ID"), dec);
 	  TAG (AT_GID, _("Real group ID"), dec);
 	  TAG (AT_EGID, _("Effective group ID"), dec);
 	  TAG (AT_CLKTCK, _("Frequency of times()"), dec);
 	  TAG (AT_PLATFORM, _("String identifying platform"), str);
 	  TAG (AT_HWCAP, _("Machine-dependent CPU capability hints"), hex);
 	  TAG (AT_FPUCW, _("Used FPU control word"), dec);
 	  TAG (AT_DCACHEBSIZE, _("Data cache block size"), dec);
 	  TAG (AT_ICACHEBSIZE, _("Instruction cache block size"), dec);
 	  TAG (AT_UCACHEBSIZE, _("Unified cache block size"), dec);
 	  TAG (AT_IGNOREPPC, _("Entry should be ignored"), dec);
 	  TAG (AT_BASE_PLATFORM, _("String identifying base platform"), str);
 	  TAG (AT_EXECFN, _("File name of executable"), str);
 	  TAG (AT_SECURE, _("Boolean, was exec setuid-like?"), dec);
 	  TAG (AT_SYSINFO, _("Special system info/entry points"), hex);
 	  TAG (AT_SYSINFO_EHDR, _("System-supplied DSO's ELF header"), hex);
 	  TAG (AT_SUN_UID, _("Effective user ID"), dec);
 	  TAG (AT_SUN_RUID, _("Real user ID"), dec);
 	  TAG (AT_SUN_GID, _("Effective group ID"), dec);
 	  TAG (AT_SUN_RGID, _("Real group ID"), dec);
 	  TAG (AT_SUN_LDELF, _("Dynamic linker's ELF header"), hex);
 	  TAG (AT_SUN_LDSHDR, _("Dynamic linker's section headers"), hex);
 	  TAG (AT_SUN_LDNAME, _("String giving name of dynamic linker"), str);
 	  TAG (AT_SUN_LPAGESZ, _("Large pagesize"), dec);
 	  TAG (AT_SUN_PLATFORM, _("Platform name string"), str);
 	  TAG (AT_SUN_HWCAP, _("Machine-dependent CPU capability hints"), hex);
 	  TAG (AT_SUN_IFLUSH, _("Should flush icache?"), dec);
 	  TAG (AT_SUN_CPU, _("CPU name string"), str);
 	  TAG (AT_SUN_EMUL_ENTRY, _("COFF entry point address"), hex);
 	  TAG (AT_SUN_EMUL_EXECFD, _("COFF executable file descriptor"), dec);
 	  TAG (AT_SUN_EXECNAME,
 	       _("Canonicalized file name given to execve"), str);
 	  TAG (AT_SUN_MMU, _("String for name of MMU module"), str);
 	  TAG (AT_SUN_LDDATA, _("Dynamic linker's data segment address"), hex);
 	  TAG (AT_SUN_AUXFLAGS,
 	       _("AF_SUN_ flags passed from the kernel"), hex);
 	}

       fprintf_filtered (file, "%-4s %-20s %-30s ",
 			plongest (type), name, description);
       switch (flavor)
 	{
 	case dec:
 	  fprintf_filtered (file, "%s\n", plongest (val));
 	  break;
 	case hex:
 	  fprintf_filtered (file, "0x%s\n", paddr_nz (val));
 	  break;
 	case str:
 	  {
 	    struct value_print_options opts;
 	    get_user_print_options (&opts);
 	    if (opts.addressprint)
 	      fprintf_filtered (file, "0x%s", paddr_nz (val));
 	    val_print_string (val, -1, 1, file, &opts);
 	    fprintf_filtered (file, "\n");
 	  }
 	  break;
 	}
       ++ents;
       if (type == AT_NULL)
 	break;
     }

   xfree (data);

   return ents;
 }

 static void
 info_auxv_command (char *cmd, int from_tty)
 {
   if (! target_has_stack)
     error (_("The program has no auxiliary information now."));
   else
     {
       int ents = fprint_target_auxv (gdb_stdout, &current_target);
       if (ents < 0)
 	error (_("No auxiliary vector found, or failed reading it."));
       else if (ents == 0)
 	error (_("Auxiliary vector is empty."));
     }
 }


 extern initialize_file_ftype _initialize_auxv; /* -Wmissing-prototypes; */

 void
 _initialize_auxv (void)
 {
   add_info ("auxv", info_auxv_command,
 	    _("Display the inferior's auxiliary vector.\n\
 This is information provided by the operating system at program startup."));
 }
	/* Auxiliary vector support for GDB, the GNU debugger.

	Copyright (C) 2004, 2005, 2006, 2007, 2008 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 "target.h"
	#include "gdbtypes.h"
	#include "command.h"
	#include "inferior.h"
	#include "valprint.h"
	#include "gdb_assert.h"

	#include "auxv.h"
	#include "elf/common.h"

	#include <unistd.h>
	#include <fcntl.h>


	/* This function is called like a to_xfer_partial hook,
	but must be called with TARGET_OBJECT_AUXV.
	It handles access via /proc/PID/auxv, which is the common method.
	This function is appropriate for doing:
	#define NATIVE_XFER_AUXV procfs_xfer_auxv
	for a native target that uses inftarg.c's child_xfer_partial hook. */

	LONGEST
	procfs_xfer_auxv (struct target_ops *ops,
	int /* enum target_object */ object,
	const char *annex,
	gdb_byte *readbuf,
	const gdb_byte *writebuf,
	ULONGEST offset,
	LONGEST len)
	{
	char *pathname;
	int fd;
	LONGEST n;

	gdb_assert (object == TARGET_OBJECT_AUXV);
	gdb_assert (readbuf \|\| writebuf);

	pathname = xstrprintf ("/proc/%d/auxv", PIDGET (inferior_ptid));
	fd = open (pathname, writebuf != NULL ? O_WRONLY : O_RDONLY);
	xfree (pathname);
	if (fd < 0)
	return -1;

	if (offset != (ULONGEST) 0
	&& lseek (fd, (off_t) offset, SEEK_SET) != (off_t) offset)
	n = -1;
	else if (readbuf != NULL)
	n = read (fd, readbuf, len);
	else
	n = write (fd, writebuf, len);

	(void) close (fd);

	return n;
	}

	/* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
	Return 0 if *READPTR is already at the end of the buffer.
	Return -1 if there is insufficient buffer for a whole entry.
	Return 1 if an entry was read into TYPEP and VALP. */
	int
	default_auxv_parse (struct target_ops ops, gdb_byte *readptr,
	gdb_byte endptr, CORE_ADDR typep, CORE_ADDR *valp)
	{
	const int sizeof_auxv_field = gdbarch_ptr_bit (target_gdbarch)
	/ TARGET_CHAR_BIT;
	gdb_byte ptr = readptr;

	if (endptr == ptr)
	return 0;

	if (endptr - ptr < sizeof_auxv_field * 2)
	return -1;

	*typep = extract_unsigned_integer (ptr, sizeof_auxv_field);
	ptr += sizeof_auxv_field;
	*valp = extract_unsigned_integer (ptr, sizeof_auxv_field);
	ptr += sizeof_auxv_field;

	*readptr = ptr;
	return 1;
	}

	/* Read one auxv entry from *READPTR, not reading locations >= ENDPTR.
	Return 0 if *READPTR is already at the end of the buffer.
	Return -1 if there is insufficient buffer for a whole entry.
	Return 1 if an entry was read into TYPEP and VALP. */
	int
	target_auxv_parse (struct target_ops ops, gdb_byte *readptr,
	gdb_byte endptr, CORE_ADDR typep, CORE_ADDR *valp)
	{
	struct target_ops *t;
	for (t = ops; t != NULL; t = t->beneath)
	if (t->to_auxv_parse != NULL)
	return t->to_auxv_parse (t, readptr, endptr, typep, valp);

	return default_auxv_parse (ops, readptr, endptr, typep, valp);
	}

	/* Extract the auxiliary vector entry with a_type matching MATCH.
	Return zero if no such entry was found, or -1 if there was
	an error getting the information. On success, return 1 after
	storing the entry's value field in VALP. /
	int
	target_auxv_search (struct target_ops ops, CORE_ADDR match, CORE_ADDR valp)
	{
	CORE_ADDR type, val;
	gdb_byte *data;
	LONGEST n = target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL, &data);
	gdb_byte *ptr = data;
	int ents = 0;

	if (n <= 0)
	return n;

	while (1)
	switch (target_auxv_parse (ops, &ptr, data + n, &type, &val))
	{
	case 1: /* Here's an entry, check it. */
	if (type == match)
	{
	xfree (data);
	*valp = val;
	return 1;
	}
	break;
	case 0: /* End of the vector. */
	xfree (data);
	return 0;
	default: /* Bogosity. */
	xfree (data);
	return -1;
	}

	/NOTREACHED/
	}


	/* Print the contents of the target's AUXV on the specified file. */
	int
	fprint_target_auxv (struct ui_file file, struct target_ops ops)
	{
	CORE_ADDR type, val;
	gdb_byte *data;
	LONGEST len = target_read_alloc (ops, TARGET_OBJECT_AUXV, NULL,
	&data);
	gdb_byte *ptr = data;
	int ents = 0;

	if (len <= 0)
	return len;

	while (target_auxv_parse (ops, &ptr, data + len, &type, &val) > 0)
	{
	const char *name = "???";
	const char *description = "";
	enum { dec, hex, str } flavor = hex;

	switch (type)
	{
	#define TAG(tag, text, kind) \
	case tag: name = #tag; description = text; flavor = kind; break
	TAG (AT_NULL, _("End of vector"), hex);
	TAG (AT_IGNORE, _("Entry should be ignored"), hex);
	TAG (AT_EXECFD, _("File descriptor of program"), dec);
	TAG (AT_PHDR, _("Program headers for program"), hex);
	TAG (AT_PHENT, _("Size of program header entry"), dec);
	TAG (AT_PHNUM, _("Number of program headers"), dec);
	TAG (AT_PAGESZ, _("System page size"), dec);
	TAG (AT_BASE, _("Base address of interpreter"), hex);
	TAG (AT_FLAGS, _("Flags"), hex);
	TAG (AT_ENTRY, _("Entry point of program"), hex);
	TAG (AT_NOTELF, _("Program is not ELF"), dec);
	TAG (AT_UID, _("Real user ID"), dec);
	TAG (AT_EUID, _("Effective user ID"), dec);
	TAG (AT_GID, _("Real group ID"), dec);
	TAG (AT_EGID, _("Effective group ID"), dec);
	TAG (AT_CLKTCK, _("Frequency of times()"), dec);
	TAG (AT_PLATFORM, _("String identifying platform"), str);
	TAG (AT_HWCAP, _("Machine-dependent CPU capability hints"), hex);
	TAG (AT_FPUCW, _("Used FPU control word"), dec);
	TAG (AT_DCACHEBSIZE, _("Data cache block size"), dec);
	TAG (AT_ICACHEBSIZE, _("Instruction cache block size"), dec);
	TAG (AT_UCACHEBSIZE, _("Unified cache block size"), dec);
	TAG (AT_IGNOREPPC, _("Entry should be ignored"), dec);
	TAG (AT_BASE_PLATFORM, _("String identifying base platform"), str);
	TAG (AT_EXECFN, _("File name of executable"), str);
	TAG (AT_SECURE, _("Boolean, was exec setuid-like?"), dec);
	TAG (AT_SYSINFO, _("Special system info/entry points"), hex);
	TAG (AT_SYSINFO_EHDR, _("System-supplied DSO's ELF header"), hex);
	TAG (AT_SUN_UID, _("Effective user ID"), dec);
	TAG (AT_SUN_RUID, _("Real user ID"), dec);
	TAG (AT_SUN_GID, _("Effective group ID"), dec);
	TAG (AT_SUN_RGID, _("Real group ID"), dec);
	TAG (AT_SUN_LDELF, _("Dynamic linker's ELF header"), hex);
	TAG (AT_SUN_LDSHDR, _("Dynamic linker's section headers"), hex);
	TAG (AT_SUN_LDNAME, _("String giving name of dynamic linker"), str);
	TAG (AT_SUN_LPAGESZ, _("Large pagesize"), dec);
	TAG (AT_SUN_PLATFORM, _("Platform name string"), str);
	TAG (AT_SUN_HWCAP, _("Machine-dependent CPU capability hints"), hex);
	TAG (AT_SUN_IFLUSH, _("Should flush icache?"), dec);
	TAG (AT_SUN_CPU, _("CPU name string"), str);
	TAG (AT_SUN_EMUL_ENTRY, _("COFF entry point address"), hex);
	TAG (AT_SUN_EMUL_EXECFD, _("COFF executable file descriptor"), dec);
	TAG (AT_SUN_EXECNAME,
	_("Canonicalized file name given to execve"), str);
	TAG (AT_SUN_MMU, _("String for name of MMU module"), str);
	TAG (AT_SUN_LDDATA, _("Dynamic linker's data segment address"), hex);
	TAG (AT_SUN_AUXFLAGS,
	_("AF_SUN_ flags passed from the kernel"), hex);
	}

	fprintf_filtered (file, "%-4s %-20s %-30s ",
	plongest (type), name, description);
	switch (flavor)
	{
	case dec:
	fprintf_filtered (file, "%s\n", plongest (val));
	break;
	case hex:
	fprintf_filtered (file, "0x%s\n", paddr_nz (val));
	break;
	case str:
	{
	struct value_print_options opts;
	get_user_print_options (&opts);
	if (opts.addressprint)
	fprintf_filtered (file, "0x%s", paddr_nz (val));
	val_print_string (val, -1, 1, file, &opts);
	fprintf_filtered (file, "\n");
	}
	break;
	}
	++ents;
	if (type == AT_NULL)
	break;
	}

	xfree (data);

	return ents;
	}

	static void
	info_auxv_command (char *cmd, int from_tty)
	{
	if (! target_has_stack)
	error (_("The program has no auxiliary information now."));
	else
	{
	int ents = fprint_target_auxv (gdb_stdout, &current_target);
	if (ents < 0)
	error (_("No auxiliary vector found, or failed reading it."));
	else if (ents == 0)
	error (_("Auxiliary vector is empty."));
	}
	}


	extern initialize_file_ftype _initialize_auxv; /* -Wmissing-prototypes; */

	void
	_initialize_auxv (void)
	{
	add_info ("auxv", info_auxv_command,
	_("Display the inferior's auxiliary vector.\n\
	This is information provided by the operating system at program startup."));
	}