2005-12-13 Ulrich Drepper <drepper@redhat.com>

1 files changed, 590 insertions, 0 deletions

diff --git a/elf/dl-sysdep.c b/elf/dl-sysdep.c
new file mode 100644
index 0000000000..985e2b8f77
--- /dev/null
+++ b/elf/dl-sysdep.c
@@ -0,0 +1,590 @@
+/* Operating system support for run-time dynamic linker.  Generic Unix version.
+   Copyright (C) 1995-1998, 2000-2003, 2004, 2005 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <assert.h>
+#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <libintl.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <ldsodefs.h>
+#include <stdio-common/_itoa.h>
+#include <fpu_control.h>
+
+#include <entry.h>
+#include <dl-machine.h>
+#include <dl-procinfo.h>
+#include <dl-osinfo.h>
+#include <hp-timing.h>
+#include <tls.h>
+
+#ifdef _DL_FIRST_PLATFORM
+# define _DL_FIRST_EXTRA (_DL_FIRST_PLATFORM + _DL_PLATFORMS_COUNT)
+#else
+# define _DL_FIRST_EXTRA _DL_HWCAP_COUNT
+#endif
+
+extern char **_environ attribute_hidden;
+extern void _end attribute_hidden;
+
+/* Protect SUID program against misuse of file descriptors.  */
+extern void __libc_check_standard_fds (void);
+
+#ifdef NEED_DL_BASE_ADDR
+ElfW(Addr) _dl_base_addr;
+#endif
+int __libc_enable_secure attribute_relro = 0;
+INTVARDEF(__libc_enable_secure)
+int __libc_multiple_libcs = 0;	/* Defining this here avoids the inclusion
+				   of init-first.  */
+/* This variable contains the lowest stack address ever used.  */
+void *__libc_stack_end attribute_relro = NULL;
+rtld_hidden_data_def(__libc_stack_end)
+static ElfW(auxv_t) *_dl_auxv attribute_relro;
+
+#ifndef DL_FIND_ARG_COMPONENTS
+# define DL_FIND_ARG_COMPONENTS(cookie, argc, argv, envp, auxp)	\
+  do {									      \
+    void **_tmp;							      \
+    (argc) = *(long int *) cookie;					      \
+    (argv) = (char **) ((long int *) cookie + 1);			      \
+    (envp) = (argv) + (argc) + 1;					      \
+    for (_tmp = (void **) (envp); *_tmp; ++_tmp)			      \
+      continue;								      \
+    (auxp) = (void *) ++_tmp;						      \
+  } while (0)
+#endif
+
+#ifndef DL_STACK_END
+# define DL_STACK_END(cookie) ((void *) (cookie))
+#endif
+
+ElfW(Addr)
+_dl_sysdep_start (void **start_argptr,
+		  void (*dl_main) (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
+				   ElfW(Addr) *user_entry))
+{
+  const ElfW(Phdr) *phdr = NULL;
+  ElfW(Word) phnum = 0;
+  ElfW(Addr) user_entry;
+  ElfW(auxv_t) *av;
+#ifdef HAVE_AUX_SECURE
+# define set_seen(tag) (tag)	/* Evaluate for the side effects.  */
+# define set_seen_secure() ((void) 0)
+#else
+  uid_t uid = 0;
+  gid_t gid = 0;
+  unsigned int seen = 0;
+# define set_seen_secure() (seen = -1)
+# ifdef HAVE_AUX_XID
+#  define set_seen(tag) (tag)	/* Evaluate for the side effects.  */
+# else
+#  define M(type) (1 << (type))
+#  define set_seen(tag) seen |= M ((tag)->a_type)
+# endif
+#endif
+#ifdef NEED_DL_SYSINFO
+  uintptr_t new_sysinfo = 0;
+#endif
+
+  __libc_stack_end = DL_STACK_END (start_argptr);
+  DL_FIND_ARG_COMPONENTS (start_argptr, _dl_argc, INTUSE(_dl_argv), _environ,
+			  _dl_auxv);
+
+  user_entry = (ElfW(Addr)) ENTRY_POINT;
+  GLRO(dl_platform) = NULL; /* Default to nothing known about the platform.  */
+
+  for (av = _dl_auxv; av->a_type != AT_NULL; set_seen (av++))
+    switch (av->a_type)
+      {
+      case AT_PHDR:
+	phdr = (void *) av->a_un.a_val;
+	break;
+      case AT_PHNUM:
+	phnum = av->a_un.a_val;
+	break;
+      case AT_PAGESZ:
+	GLRO(dl_pagesize) = av->a_un.a_val;
+	break;
+      case AT_ENTRY:
+	user_entry = av->a_un.a_val;
+	break;
+#ifdef NEED_DL_BASE_ADDR
+      case AT_BASE:
+	_dl_base_addr = av->a_un.a_val;
+	break;
+#endif
+#ifndef HAVE_AUX_SECURE
+      case AT_UID:
+      case AT_EUID:
+	uid ^= av->a_un.a_val;
+	break;
+      case AT_GID:
+      case AT_EGID:
+	gid ^= av->a_un.a_val;
+	break;
+#endif
+      case AT_SECURE:
+#ifndef HAVE_AUX_SECURE
+	seen = -1;
+#endif
+	INTUSE(__libc_enable_secure) = av->a_un.a_val;
+	break;
+      case AT_PLATFORM:
+	GLRO(dl_platform) = (void *) av->a_un.a_val;
+	break;
+      case AT_HWCAP:
+	GLRO(dl_hwcap) = (unsigned long int) av->a_un.a_val;
+	break;
+      case AT_CLKTCK:
+	GLRO(dl_clktck) = av->a_un.a_val;
+	break;
+      case AT_FPUCW:
+	GLRO(dl_fpu_control) = av->a_un.a_val;
+	break;
+#ifdef NEED_DL_SYSINFO
+      case AT_SYSINFO:
+	new_sysinfo = av->a_un.a_val;
+	break;
+#endif
+#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
+      case AT_SYSINFO_EHDR:
+	GLRO(dl_sysinfo_dso) = (void *) av->a_un.a_val;
+	break;
+#endif
+#ifdef DL_PLATFORM_AUXV
+      DL_PLATFORM_AUXV
+#endif
+      }
+
+#ifndef HAVE_AUX_SECURE
+  if (seen != -1)
+    {
+      /* Fill in the values we have not gotten from the kernel through the
+	 auxiliary vector.  */
+# ifndef HAVE_AUX_XID
+#  define SEE(UID, var, uid) \
+   if ((seen & M (AT_##UID)) == 0) var ^= __get##uid ()
+      SEE (UID, uid, uid);
+      SEE (EUID, uid, euid);
+      SEE (GID, gid, gid);
+      SEE (EGID, gid, egid);
+# endif
+
+      /* If one of the two pairs of IDs does not match this is a setuid
+	 or setgid run.  */
+      INTUSE(__libc_enable_secure) = uid | gid;
+    }
+#endif
+
+#ifndef HAVE_AUX_PAGESIZE
+  if (GLRO(dl_pagesize) == 0)
+    GLRO(dl_pagesize) = __getpagesize ();
+#endif
+
+#if defined NEED_DL_SYSINFO
+  /* Only set the sysinfo value if we also have the vsyscall DSO.  */
+  if (GLRO(dl_sysinfo_dso) != 0 && new_sysinfo)
+    GLRO(dl_sysinfo) = new_sysinfo;
+#endif
+
+#ifdef DL_SYSDEP_INIT
+  DL_SYSDEP_INIT;
+#endif
+
+#ifdef DL_PLATFORM_INIT
+  DL_PLATFORM_INIT;
+#endif
+
+  /* Determine the length of the platform name.  */
+  if (GLRO(dl_platform) != NULL)
+    GLRO(dl_platformlen) = strlen (GLRO(dl_platform));
+
+  if (__sbrk (0) == &_end)
+    /* The dynamic linker was run as a program, and so the initial break
+       starts just after our bss, at &_end.  The malloc in dl-minimal.c
+       will consume the rest of this page, so tell the kernel to move the
+       break up that far.  When the user program examines its break, it
+       will see this new value and not clobber our data.  */
+    __sbrk (GLRO(dl_pagesize)
+	    - ((&_end - (void *) 0) & (GLRO(dl_pagesize) - 1)));
+
+  /* If this is a SUID program we make sure that FDs 0, 1, and 2 are
+     allocated.  If necessary we are doing it ourself.  If it is not
+     possible we stop the program.  */
+  if (__builtin_expect (INTUSE(__libc_enable_secure), 0))
+    __libc_check_standard_fds ();
+
+  (*dl_main) (phdr, phnum, &user_entry);
+  return user_entry;
+}
+
+void
+internal_function
+_dl_sysdep_start_cleanup (void)
+{
+}
+
+void
+internal_function
+_dl_show_auxv (void)
+{
+  char buf[64];
+  ElfW(auxv_t) *av;
+
+  /* Terminate string.  */
+  buf[63] = '\0';
+
+  /* The following code assumes that the AT_* values are encoded
+     starting from 0 with AT_NULL, 1 for AT_IGNORE, and all other values
+     close by (otherwise the array will be too large).  In case we have
+     to support a platform where these requirements are not fulfilled
+     some alternative implementation has to be used.  */
+  for (av = _dl_auxv; av->a_type != AT_NULL; ++av)
+    {
+      static const struct
+      {
+	const char label[20];
+	enum { unknown = 0, dec, hex, str, ignore } form;
+      } auxvars[] =
+	{
+	  [AT_EXECFD - 2] =		{ "AT_EXECFD:       ", dec },
+	  [AT_PHDR - 2] =		{ "AT_PHDR:         0x", hex },
+	  [AT_PHENT - 2] =		{ "AT_PHENT:        ", dec },
+	  [AT_PHNUM - 2] =		{ "AT_PHNUM:        ", dec },
+	  [AT_PAGESZ - 2] =		{ "AT_PAGESZ:       ", dec },
+	  [AT_BASE - 2] =		{ "AT_BASE:         0x", hex },
+	  [AT_FLAGS - 2] =		{ "AT_FLAGS:        0x", hex },
+	  [AT_ENTRY - 2] =		{ "AT_ENTRY:        0x", hex },
+	  [AT_NOTELF - 2] =		{ "AT_NOTELF:       ", hex },
+	  [AT_UID - 2] =		{ "AT_UID:          ", dec },
+	  [AT_EUID - 2] =		{ "AT_EUID:         ", dec },
+	  [AT_GID - 2] =		{ "AT_GID:          ", dec },
+	  [AT_EGID - 2] =		{ "AT_EGID:         ", dec },
+	  [AT_PLATFORM - 2] =		{ "AT_PLATFORM:     ", str },
+	  [AT_HWCAP - 2] =		{ "AT_HWCAP:        ", hex },
+	  [AT_CLKTCK - 2] =		{ "AT_CLKTCK:       ", dec },
+	  [AT_FPUCW - 2] =		{ "AT_FPUCW:        ", hex },
+	  [AT_DCACHEBSIZE - 2] =	{ "AT_DCACHEBSIZE:  0x", hex },
+	  [AT_ICACHEBSIZE - 2] =	{ "AT_ICACHEBSIZE:  0x", hex },
+	  [AT_UCACHEBSIZE - 2] =	{ "AT_UCACHEBSIZE:  0x", hex },
+	  [AT_IGNOREPPC - 2] =		{ "AT_IGNOREPPC", ignore },
+	  [AT_SECURE - 2] =		{ "AT_SECURE:       ", dec },
+	  [AT_SYSINFO - 2] =		{ "AT_SYSINFO:      0x", hex },
+	  [AT_SYSINFO_EHDR - 2] =	{ "AT_SYSINFO_EHDR: 0x", hex },
+	};
+      unsigned int idx = (unsigned int) (av->a_type - 2);
+
+      if ((unsigned int) av->a_type < 2u || auxvars[idx].form == ignore)
+	continue;
+
+      assert (AT_NULL == 0);
+      assert (AT_IGNORE == 1);
+
+      if (av->a_type == AT_HWCAP)
+	{
+	  /* This is handled special.  */
+	  if (_dl_procinfo (av->a_un.a_val) == 0)
+	    continue;
+	}
+
+      if (idx < sizeof (auxvars) / sizeof (auxvars[0])
+	  && auxvars[idx].form != unknown)
+	{
+	  const char *val = (char *) av->a_un.a_val;
+
+	  if (__builtin_expect (auxvars[idx].form, dec) == dec)
+	    val = _itoa ((unsigned long int) av->a_un.a_val,
+			 buf + sizeof buf - 1, 10, 0);
+	  else if (__builtin_expect (auxvars[idx].form, hex) == hex)
+	    val = _itoa ((unsigned long int) av->a_un.a_val,
+			 buf + sizeof buf - 1, 16, 0);
+
+	  _dl_printf ("%s%s\n", auxvars[idx].label, val);
+
+	  continue;
+	}
+
+      /* Unknown value: print a generic line.  */
+      char buf2[17];
+      buf[sizeof (buf2) - 1] = '\0';
+      const char *val2 = _itoa ((unsigned long int) av->a_un.a_val,
+				buf2 + sizeof buf2 - 1, 16, 0);
+      const char *val =  _itoa ((unsigned long int) av->a_type,
+				buf + sizeof buf - 1, 16, 0);
+      _dl_printf ("AT_??? (0x%s): 0x%s\n", val, val2);
+    }
+}
+
+
+/* Return an array of useful/necessary hardware capability names.  */
+const struct r_strlenpair *
+internal_function
+_dl_important_hwcaps (const char *platform, size_t platform_len, size_t *sz,
+		      size_t *max_capstrlen)
+{
+  /* Determine how many important bits are set.  */
+  uint64_t masked = GLRO(dl_hwcap) & GLRO(dl_hwcap_mask);
+  size_t cnt = platform != NULL;
+  size_t n, m;
+  size_t total;
+  struct r_strlenpair *temp;
+  struct r_strlenpair *result;
+  struct r_strlenpair *rp;
+  char *cp;
+
+  /* Count the number of bits set in the masked value.  */
+  for (n = 0; (~((1ULL << n) - 1) & masked) != 0; ++n)
+    if ((masked & (1ULL << n)) != 0)
+      ++cnt;
+
+#if (defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO) && defined SHARED
+  /* The system-supplied DSO can contain a note of type 2, vendor "GNU".
+     This gives us a list of names to treat as fake hwcap bits.  */
+
+  const char *dsocaps = NULL;
+  size_t dsocapslen = 0;
+  if (GLRO(dl_sysinfo_map) != NULL)
+    {
+      const ElfW(Phdr) *const phdr = GLRO(dl_sysinfo_map)->l_phdr;
+      const ElfW(Word) phnum = GLRO(dl_sysinfo_map)->l_phnum;
+      for (uint_fast16_t i = 0; i < phnum; ++i)
+	if (phdr[i].p_type == PT_NOTE)
+	  {
+	    const ElfW(Addr) start = (phdr[i].p_vaddr
+				      + GLRO(dl_sysinfo_map)->l_addr);
+	    const struct
+	    {
+	      ElfW(Word) vendorlen;
+	      ElfW(Word) datalen;
+	      ElfW(Word) type;
+	    } *note = (const void *) start;
+	    while ((ElfW(Addr)) (note + 1) - start < phdr[i].p_memsz)
+	      {
+#define ROUND(len) (((len) + sizeof (ElfW(Word)) - 1) & -sizeof (ElfW(Word)))
+		if (note->type == 2
+		    && note->vendorlen == sizeof "GNU"
+		    && !memcmp ((note + 1), "GNU", sizeof "GNU")
+		    && note->datalen > 2 * sizeof (ElfW(Word)) + 2)
+		  {
+		    const ElfW(Word) *p = ((const void *) (note + 1)
+					   + ROUND (sizeof "GNU"));
+		    cnt += *p++;
+		    ++p;	/* Skip mask word.  */
+		    dsocaps = (const char *) p;
+		    dsocapslen = note->datalen - sizeof *p * 2;
+		    break;
+		  }
+		note = ((const void *) (note + 1)
+			+ ROUND (note->vendorlen) + ROUND (note->datalen));
+	      }
+	    if (dsocaps != NULL)
+	      break;
+	  }
+    }
+#endif
+
+#ifdef USE_TLS
+  /* For TLS enabled builds always add 'tls'.  */
+  ++cnt;
+#else
+  if (cnt == 0)
+    {
+      /* If we no have platform name and no important capability we only
+	 have the base directory to search.  */
+      result = (struct r_strlenpair *) malloc (sizeof (*result));
+      if (result == NULL)
+	goto no_memory;
+
+      result[0].str = (char *) result;	/* Does not really matter.  */
+      result[0].len = 0;
+
+      *sz = 1;
+      return result;
+    }
+#endif
+
+  /* Create temporary data structure to generate result table.  */
+  temp = (struct r_strlenpair *) alloca (cnt * sizeof (*temp));
+  m = 0;
+#if defined NEED_DL_SYSINFO || defined NEED_DL_SYSINFO_DSO
+  if (dsocaps != NULL)
+    {
+      const ElfW(Word) mask = ((const ElfW(Word) *) dsocaps)[-1];
+      GLRO(dl_hwcap) |= (uint64_t) mask << _DL_FIRST_EXTRA;
+      size_t len;
+      for (const char *p = dsocaps; p < dsocaps + dsocapslen; p += len + 1)
+	{
+	  uint_fast8_t bit = *p++;
+	  len = strlen (p);
+
+	  /* Skip entries that are not enabled in the mask word.  */
+	  if (__builtin_expect (mask & ((ElfW(Word)) 1 << bit), 1))
+	    {
+	      temp[m].str = p;
+	      temp[m].len = len;
+	      ++m;
+	    }
+	  else
+	    --cnt;
+	}
+    }
+#endif
+  for (n = 0; masked != 0; ++n)
+    if ((masked & (1ULL << n)) != 0)
+      {
+	temp[m].str = _dl_hwcap_string (n);
+	temp[m].len = strlen (temp[m].str);
+	masked ^= 1ULL << n;
+	++m;
+      }
+  if (platform != NULL)
+    {
+      temp[m].str = platform;
+      temp[m].len = platform_len;
+      ++m;
+    }
+#ifdef USE_TLS
+  temp[m].str = "tls";
+  temp[m].len = 3;
+  ++m;
+#endif
+  assert (m == cnt);
+
+  /* Determine the total size of all strings together.  */
+  if (cnt == 1)
+    total = temp[0].len + 1;
+  else
+    {
+      total = (1UL << (cnt - 2)) * (temp[0].len + temp[cnt - 1].len + 2);
+      for (n = 1; n + 1 < cnt; ++n)
+	total += (1UL << (cnt - 3)) * (temp[n].len + 1);
+    }
+
+  /* The result structure: we use a very compressed way to store the
+     various combinations of capability names.  */
+  *sz = 1 << cnt;
+  result = (struct r_strlenpair *) malloc (*sz * sizeof (*result) + total);
+  if (result == NULL)
+    {
+#ifndef USE_TLS
+    no_memory:
+#endif
+      _dl_signal_error (ENOMEM, NULL, NULL,
+			N_("cannot create capability list"));
+    }
+
+  if (cnt == 1)
+    {
+      result[0].str = (char *) (result + *sz);
+      result[0].len = temp[0].len + 1;
+      result[1].str = (char *) (result + *sz);
+      result[1].len = 0;
+      cp = __mempcpy ((char *) (result + *sz), temp[0].str, temp[0].len);
+      *cp = '/';
+      *sz = 2;
+      *max_capstrlen = result[0].len;
+
+      return result;
+    }
+
+  /* Fill in the information.  This follows the following scheme
+     (indeces from TEMP for four strings):
+	entry #0: 0, 1, 2, 3	binary: 1111
+	      #1: 0, 1, 3	        1101
+	      #2: 0, 2, 3	        1011
+	      #3: 0, 3		        1001
+     This allows the representation of all possible combinations of
+     capability names in the string.  First generate the strings.  */
+  result[1].str = result[0].str = cp = (char *) (result + *sz);
+#define add(idx) \
+      cp = __mempcpy (__mempcpy (cp, temp[idx].str, temp[idx].len), "/", 1);
+  if (cnt == 2)
+    {
+      add (1);
+      add (0);
+    }
+  else
+    {
+      n = 1 << (cnt - 1);
+      do
+	{
+	  n -= 2;
+
+	  /* We always add the last string.  */
+	  add (cnt - 1);
+
+	  /* Add the strings which have the bit set in N.  */
+	  for (m = cnt - 2; m > 0; --m)
+	    if ((n & (1 << m)) != 0)
+	      add (m);
+
+	  /* Always add the first string.  */
+	  add (0);
+	}
+      while (n != 0);
+    }
+#undef add
+
+  /* Now we are ready to install the string pointers and length.  */
+  for (n = 0; n < (1UL << cnt); ++n)
+    result[n].len = 0;
+  n = cnt;
+  do
+    {
+      size_t mask = 1 << --n;
+
+      rp = result;
+      for (m = 1 << cnt; m > 0; ++rp)
+	if ((--m & mask) != 0)
+	  rp->len += temp[n].len + 1;
+    }
+  while (n != 0);
+
+  /* The first half of the strings all include the first string.  */
+  n = (1 << cnt) - 2;
+  rp = &result[2];
+  while (n != (1UL << (cnt - 1)))
+    {
+      if ((--n & 1) != 0)
+	rp[0].str = rp[-2].str + rp[-2].len;
+      else
+	rp[0].str = rp[-1].str;
+      ++rp;
+    }
+
+  /* The second half starts right after the first part of the string of
+     the corresponding entry in the first half.  */
+  do
+    {
+      rp[0].str = rp[-(1 << (cnt - 1))].str + temp[cnt - 1].len + 1;
+      ++rp;
+    }
+  while (--n != 0);
+
+  /* The maximum string length.  */
+  *max_capstrlen = result[0].len;
+
+  return result;
+}