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authorUlrich Drepper <drepper@gmail.com>2011-09-12 16:20:40 -0400
committerUlrich Drepper <drepper@gmail.com>2011-09-12 16:20:40 -0400
commit037e9fe21c92216ef7032ea2796781ec27ca182a (patch)
tree00942e9c064de8760a4b39e2c45acada37a7989e /elf/rtld.c
parenta7c8e6a1478de9f990b11e5e853318ccbe4330f2 (diff)
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Revert "Remove last use of USE___THREAD"
This reverts commit de82006d43e198fd162807c9adc720c7ebd728a3.

Conflicts:

	ChangeLog
Diffstat (limited to 'elf/rtld.c')
-rw-r--r--elf/rtld.c138
1 files changed, 135 insertions, 3 deletions
diff --git a/elf/rtld.c b/elf/rtld.c
index 0af932579a..b3959a34d0 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -306,9 +306,21 @@ _dl_start_final (void *arg, struct dl_start_final_info *info)
   GL(dl_rtld_map).l_text_end = (ElfW(Addr)) _etext;
   /* Copy the TLS related data if necessary.  */
 #ifndef DONT_USE_BOOTSTRAP_MAP
-# if NO_TLS_OFFSET != 0
+# if USE___THREAD
+  assert (info->l.l_tls_modid != 0);
+  GL(dl_rtld_map).l_tls_blocksize = info->l.l_tls_blocksize;
+  GL(dl_rtld_map).l_tls_align = info->l.l_tls_align;
+  GL(dl_rtld_map).l_tls_firstbyte_offset = info->l.l_tls_firstbyte_offset;
+  GL(dl_rtld_map).l_tls_initimage_size = info->l.l_tls_initimage_size;
+  GL(dl_rtld_map).l_tls_initimage = info->l.l_tls_initimage;
+  GL(dl_rtld_map).l_tls_offset = info->l.l_tls_offset;
+  GL(dl_rtld_map).l_tls_modid = 1;
+# else
+#  if NO_TLS_OFFSET != 0
   GL(dl_rtld_map).l_tls_offset = NO_TLS_OFFSET;
+#  endif
 # endif
+
 #endif
 
 #if HP_TIMING_AVAIL
@@ -390,6 +402,9 @@ _dl_start (void *arg)
        ++cnt)
     bootstrap_map.l_info[cnt] = 0;
 # endif
+# if USE___THREAD
+  bootstrap_map.l_tls_modid = 0;
+# endif
 #endif
 
   /* Figure out the run-time load address of the dynamic linker itself.  */
@@ -403,6 +418,123 @@ _dl_start (void *arg)
   bootstrap_map.l_tls_offset = NO_TLS_OFFSET;
 #endif
 
+  /* Get the dynamic linker's own program header.  First we need the ELF
+     file header.  The `_begin' symbol created by the linker script points
+     to it.  When we have something like GOTOFF relocs, we can use a plain
+     reference to find the runtime address.  Without that, we have to rely
+     on the `l_addr' value, which is not the value we want when prelinked.  */
+#if USE___THREAD
+  dtv_t initdtv[3];
+  ElfW(Ehdr) *ehdr
+# ifdef DONT_USE_BOOTSTRAP_MAP
+    = (ElfW(Ehdr) *) &_begin;
+# else
+#  error This will not work with prelink.
+    = (ElfW(Ehdr) *) bootstrap_map.l_addr;
+# endif
+  ElfW(Phdr) *phdr = (ElfW(Phdr) *) ((void *) ehdr + ehdr->e_phoff);
+  size_t cnt = ehdr->e_phnum;	/* PT_TLS is usually the last phdr.  */
+  while (cnt-- > 0)
+    if (phdr[cnt].p_type == PT_TLS)
+      {
+	void *tlsblock;
+	size_t max_align = MAX (TLS_INIT_TCB_ALIGN, phdr[cnt].p_align);
+	char *p;
+
+	bootstrap_map.l_tls_blocksize = phdr[cnt].p_memsz;
+	bootstrap_map.l_tls_align = phdr[cnt].p_align;
+	if (phdr[cnt].p_align == 0)
+	  bootstrap_map.l_tls_firstbyte_offset = 0;
+	else
+	  bootstrap_map.l_tls_firstbyte_offset = (phdr[cnt].p_vaddr
+						  & (phdr[cnt].p_align - 1));
+	assert (bootstrap_map.l_tls_blocksize != 0);
+	bootstrap_map.l_tls_initimage_size = phdr[cnt].p_filesz;
+	bootstrap_map.l_tls_initimage = (void *) (bootstrap_map.l_addr
+						  + phdr[cnt].p_vaddr);
+
+	/* We can now allocate the initial TLS block.  This can happen
+	   on the stack.  We'll get the final memory later when we
+	   know all about the various objects loaded at startup
+	   time.  */
+# if TLS_TCB_AT_TP
+	tlsblock = alloca (roundup (bootstrap_map.l_tls_blocksize,
+				    TLS_INIT_TCB_ALIGN)
+			   + TLS_INIT_TCB_SIZE
+			   + max_align);
+# elif TLS_DTV_AT_TP
+	tlsblock = alloca (roundup (TLS_INIT_TCB_SIZE,
+				    bootstrap_map.l_tls_align)
+			   + bootstrap_map.l_tls_blocksize
+			   + max_align);
+# else
+	/* In case a model with a different layout for the TCB and DTV
+	   is defined add another #elif here and in the following #ifs.  */
+#  error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+	/* Align the TLS block.  */
+	tlsblock = (void *) (((uintptr_t) tlsblock + max_align - 1)
+			     & ~(max_align - 1));
+
+	/* Initialize the dtv.  [0] is the length, [1] the generation
+	   counter.  */
+	initdtv[0].counter = 1;
+	initdtv[1].counter = 0;
+
+	/* Initialize the TLS block.  */
+# if TLS_TCB_AT_TP
+	initdtv[2].pointer = tlsblock;
+# elif TLS_DTV_AT_TP
+	bootstrap_map.l_tls_offset = roundup (TLS_INIT_TCB_SIZE,
+					      bootstrap_map.l_tls_align);
+	initdtv[2].pointer = (char *) tlsblock + bootstrap_map.l_tls_offset;
+# else
+#  error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+	p = __mempcpy (initdtv[2].pointer, bootstrap_map.l_tls_initimage,
+		       bootstrap_map.l_tls_initimage_size);
+# ifdef HAVE_BUILTIN_MEMSET
+	__builtin_memset (p, '\0', (bootstrap_map.l_tls_blocksize
+				    - bootstrap_map.l_tls_initimage_size));
+# else
+	{
+	  size_t remaining = (bootstrap_map.l_tls_blocksize
+			      - bootstrap_map.l_tls_initimage_size);
+	  while (remaining-- > 0)
+	    *p++ = '\0';
+	}
+# endif
+
+	/* Install the pointer to the dtv.  */
+
+	/* Initialize the thread pointer.  */
+# if TLS_TCB_AT_TP
+	bootstrap_map.l_tls_offset
+	  = roundup (bootstrap_map.l_tls_blocksize, TLS_INIT_TCB_ALIGN);
+
+	INSTALL_DTV ((char *) tlsblock + bootstrap_map.l_tls_offset,
+		     initdtv);
+
+	const char *lossage = TLS_INIT_TP ((char *) tlsblock
+					   + bootstrap_map.l_tls_offset, 0);
+# elif TLS_DTV_AT_TP
+	INSTALL_DTV (tlsblock, initdtv);
+	const char *lossage = TLS_INIT_TP (tlsblock, 0);
+# else
+#  error "Either TLS_TCB_AT_TP or TLS_DTV_AT_TP must be defined"
+# endif
+	if (__builtin_expect (lossage != NULL, 0))
+	  _dl_fatal_printf ("cannot set up thread-local storage: %s\n",
+			    lossage);
+
+	/* So far this is module number one.  */
+	bootstrap_map.l_tls_modid = 1;
+
+	/* There can only be one PT_TLS entry.  */
+	break;
+      }
+#endif	/* USE___THREAD */
+
 #ifdef ELF_MACHINE_BEFORE_RTLD_RELOC
   ELF_MACHINE_BEFORE_RTLD_RELOC (bootstrap_map.l_info);
 #endif
@@ -647,7 +779,7 @@ cannot allocate TLS data structures for initial thread");
 
   /* And finally install it for the main thread.  If ld.so itself uses
      TLS we know the thread pointer was initialized earlier.  */
-  const char *lossage = TLS_INIT_TP (tcbp, 0);
+  const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
   if (__builtin_expect (lossage != NULL, 0))
     _dl_fatal_printf ("cannot set up thread-local storage: %s\n", lossage);
   tls_init_tp_called = true;
@@ -2178,7 +2310,7 @@ ERROR: ld.so: object '%s' cannot be loaded as audit interface: %s; ignored.\n",
      TLS we know the thread pointer was initialized earlier.  */
   if (! tls_init_tp_called)
     {
-      const char *lossage = TLS_INIT_TP (tcbp, 0);
+      const char *lossage = TLS_INIT_TP (tcbp, USE___THREAD);
       if (__builtin_expect (lossage != NULL, 0))
 	_dl_fatal_printf ("cannot set up thread-local storage: %s\n",
 			  lossage);