Update.

2003-04-22  Roland McGrath  <roland@redhat.com>

	* elf/elf.h (AT_SYSINFO_EHDR): New macro, replaces AT_SYSINFO_EH_FRAME.
	* sysdeps/generic/ldsodefs.h (struct rtld_global): Remove
	dl_sysinfo_eh_frame member, add dl_sysinfo_dso member instead.
	* elf/dl-support.c: Update defn.
	* sysdeps/generic/libc-start.c: Don't call __register_frame_info_bases.
	* sysdeps/generic/dl-sysdep.c (_dl_sysdep_start) [NEED_DL_SYSINFO]:
	Set GL(dl_sysinfo_dso) from AT_SYSINFO_EHDR.
	(_dl_show_auxv): Grok AT_SYSINFO_EHDR, not AT_SYSINFO_EH_FRAME.
	* elf/rtld.c (dl_main) [NEED_DL_SYSINFO]: If GL(dl_sysinfo_dso) is
	set, set up a link_map for the preloaded, prelinked object.

ChangeLog

@@ -1,3 +1,16 @@
+2003-04-22  Roland McGrath  <roland@redhat.com>
+
+	* elf/elf.h (AT_SYSINFO_EHDR): New macro, replaces AT_SYSINFO_EH_FRAME.
+	* sysdeps/generic/ldsodefs.h (struct rtld_global): Remove
+	dl_sysinfo_eh_frame member, add dl_sysinfo_dso member instead.
+	* elf/dl-support.c: Update defn.
+	* sysdeps/generic/libc-start.c: Don't call __register_frame_info_bases.
+	* sysdeps/generic/dl-sysdep.c (_dl_sysdep_start) [NEED_DL_SYSINFO]:
+	Set GL(dl_sysinfo_dso) from AT_SYSINFO_EHDR.
+	(_dl_show_auxv): Grok AT_SYSINFO_EHDR, not AT_SYSINFO_EH_FRAME.
+	* elf/rtld.c (dl_main) [NEED_DL_SYSINFO]: If GL(dl_sysinfo_dso) is
+	set, set up a link_map for the preloaded, prelinked object.
+
 2003-05-03  Roland McGrath  <roland@redhat.com>
 
 	* sysdeps/gnu/Makefile (generated): Append errlist-compat.c here, ...

elf/dl-support.c

@@ -127,8 +127,8 @@ size_t _dl_phnum;
 #ifdef NEED_DL_SYSINFO
 /* Needed for improved syscall handling on at least x86/Linux.  */
 uintptr_t _dl_sysinfo = DL_SYSINFO_DEFAULT;
-/* Address of the unwind info for the vsyscall page.  */
+/* Address of the ELF headers in the vsyscall page.  */
-uintptr_t _dl_sysinfo_eh_frame;
+const ElfW(Ehdr) *_dl_sysinfo_dso;
 #endif
 
 /* During the program run we must not modify the global data of

elf/rtld.c

@@ -1069,6 +1069,48 @@ of this helper program; chances are you did not intend to run this program.\n\
       assert (i == npreloads);
     }
 
+#ifdef NEED_DL_SYSINFO
+  if (GL(dl_sysinfo_dso) != NULL)
+    {
+      /* We have a prelinked DSO preloaded by the system.  */
+      GL(dl_sysinfo) = GL(dl_sysinfo_dso)->e_entry;
+
+      /* Do an abridged version of the work _dl_map_object_from_fd would do
+	 to map in the object.  It's already mapped and prelinked (and
+	 better be, since it's read-only and so we couldn't relocate it).
+	 We just want our data structures to describe it as if we had just
+	 mapped and relocated it normally.  */
+      struct link_map *l = _dl_new_object ((char *) "", "", lt_library, NULL);
+      if (__builtin_expect (l != NULL, 1))
+	{
+	  l->l_phdr = ((const void *) GL(dl_sysinfo_dso)
+		       + GL(dl_sysinfo_dso)->e_phoff);
+	  l->l_phnum = GL(dl_sysinfo_dso)->e_phnum;
+	  for (uint_fast16_t i = 0; i < l->l_phnum; ++i)
+	    {
+	      const ElfW(Phdr) *const ph = &l->l_phdr[i];
+	      if (ph->p_type == PT_DYNAMIC)
+		{
+		  l->l_ld = (void *) ph->p_vaddr;
+		  l->l_ldnum = ph->p_memsz / sizeof (ElfW(Dyn));
+		  break;
+		}
+	      if (ph->p_type == PT_LOAD)
+		assert ((void *) ph->p_vaddr == GL(dl_sysinfo_dso));
+	    }
+	  elf_get_dynamic_info (l);
+	  _dl_setup_hash (l);
+	  l->l_relocated = 1;
+
+	  /* Now that we have the info handy, use the DSO image's soname
+	     so this object can be looked up by name.  */
+	  if (l->l_info[DT_SONAME] != NULL)
+	    l->l_libname->name = ((char *) D_PTR (l, l_info[DT_STRTAB])
+				  + l->l_info[DT_SONAME]->d_un.d_val);
+	}
+    }
+#endif
+
   /* Load all the libraries specified by DT_NEEDED entries.  If LD_PRELOAD
      specified some libraries to load, these are inserted before the actual
      dependencies in the executable's searchlist for symbol resolution.  */

sysdeps/generic/dl-sysdep.c

@@ -139,8 +139,8 @@ _dl_sysdep_start (void **start_argptr,
       case AT_SYSINFO:
 	GL(dl_sysinfo) = av->a_un.a_val;
 	break;
-      case AT_SYSINFO_EH_FRAME:
+      case AT_SYSINFO_EHDR:
-	GL(dl_sysinfo_eh_frame) = av->a_un.a_val;
+	GL(dl_sysinfo_dso) = av->a_un.a_ptr;
 	break;
 #endif
 #ifdef DL_PLATFORM_AUXV
@@ -227,7 +227,7 @@ _dl_show_auxv (void)
     {
       static const struct
       {
-	const char label[23];
+	const char label[20];
 	enum { dec, hex, str } form;
       } auxvars[] =
 	{
@@ -251,8 +251,10 @@ _dl_show_auxv (void)
 	  [AT_DCACHEBSIZE - 2] =	{ "AT_DCACHEBSIZE:  0x", hex },
 	  [AT_ICACHEBSIZE - 2] =	{ "AT_ICACHEBSIZE:  0x", hex },
 	  [AT_UCACHEBSIZE - 2] =	{ "AT_UCACHEBSIZE:  0x", hex },
+#ifdef DL_NEED_SYSINFO
 	  [AT_SYSINFO - 2] =		{ "AT_SYSINFO:      0x", hex },
-	  [AT_SYSINFO_EH_FRAME - 2] =	{ "AT_SYSINFO_EH_FRAME: 0x", hex }
+	  [AT_SYSINFO_EHDR - 2] =	{ "AT_SYSINFO_EHDR: 0x", hex }
+#endif
 	};
       unsigned int idx = (unsigned int) (av->a_type - 2);
 

sysdeps/generic/ldsodefs.h

@@ -395,8 +395,9 @@ struct rtld_global
   /* Syscall handling improvements.  This is very specific to x86.  */
   EXTERN uintptr_t _dl_sysinfo;
 
-  /* Address of the unwind info for the vsyscall page.  */
+  /* The vsyscall page is a virtual DSO pre-mapped by the kernel.
-  EXTERN uintptr_t _dl_sysinfo_eh_frame;
+     This points to its ELF header.  */
+  EXTERN const ElfW(Ehdr) *_dl_sysinfo_dso;
 #endif
 
 #ifdef SHARED

sysdeps/generic/libc-start.c

@@ -28,13 +28,6 @@ extern void __libc_init_first (int argc, char **argv, char **envp);
 extern int __libc_multiple_libcs;
 extern void *__libc_stack_end;
 
-#ifdef NEED_DL_SYSINFO
-# include "unwind-dw2-fde.h"
-extern __typeof (__register_frame_info_bases)
-     INTUSE(__register_frame_info_bases);
-static struct object eh_obj;
-#endif
-
 #include <tls.h>
 #ifndef SHARED
 # include <dl-osinfo.h>
@@ -157,13 +150,6 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
     __libc_check_standard_fds ();
 #endif
 
-#ifdef NEED_DL_SYSINFO
-  /* Register the kernel's unwind table.  */
-  if (GL(dl_sysinfo_eh_frame) != 0)
-    INTUSE(__register_frame_info_bases) ((void *) GL(dl_sysinfo_eh_frame),
-					 &eh_obj, 0, 0);
-#endif
-
   /* Register the destructor of the dynamic linker if there is any.  */
   if (__builtin_expect (rtld_fini != NULL, 1))
     __cxa_atexit ((void (*) (void *)) rtld_fini, NULL, NULL);