commit 2cac9559e06044ba520e785c151fbbd25011865f
Author: Florian Weimer <fweimer@redhat.com>
Date:   Fri Aug 1 10:20:23 2025 +0200

    elf: Extract rtld_setup_phdr function from dl_main
    
    Remove historic binutils reference from comment and update
    how this data is used by applications.
    
    Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

Conflicts:
	elf/rtld.
	  (missing __ehdr_start cleanup downstream)

diff --git a/elf/rtld.c b/elf/rtld.c
index 667880e18ae816d8..a9073d4e14b07410 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -1306,6 +1306,45 @@ rtld_setup_main_map (struct link_map *main_map)
   return has_interp;
 }
 
+/* Set up the program header information for the dynamic linker
+   itself.  It can be accessed via _r_debug and dl_iterate_phdr
+   callbacks.  */
+static void
+rtld_setup_phdr (void)
+{
+  const ElfW(Ehdr) *rtld_ehdr;
+
+  /* Starting from binutils-2.23, the linker will define the magic symbol
+     __ehdr_start to point to our own ELF header if it is visible in a
+     segment that also includes the phdrs.  If that's not available, we use
+     the old method that assumes the beginning of the file is part of the
+     lowest-addressed PT_LOAD segment.  */
+#ifdef HAVE_EHDR_START
+  extern const ElfW(Ehdr) __ehdr_start __attribute__ ((visibility ("hidden")));
+  rtld_ehdr = &__ehdr_start;
+#else
+  rtld_ehdr = (void *) GL(dl_rtld_map).l_map_start;
+#endif
+  assert (rtld_ehdr->e_ehsize == sizeof *rtld_ehdr);
+  assert (rtld_ehdr->e_phentsize == sizeof (ElfW(Phdr)));
+
+  const ElfW(Phdr) *rtld_phdr = (const void *) rtld_ehdr + rtld_ehdr->e_phoff;
+
+  GL(dl_rtld_map).l_phdr = rtld_phdr;
+  GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
+
+
+  /* PT_GNU_RELRO is usually the last phdr.  */
+  size_t cnt = rtld_ehdr->e_phnum;
+  while (cnt-- > 0)
+    if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
+      {
+	GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
+	GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
+	break;
+      }
+}
+
 /* Adjusts the contents of the stack and related globals for the user
    entry point.  The ld.so processed skip_args arguments and bumped
    _dl_argv and _dl_argc accordingly.  Those arguments are removed from
@@ -1790,39 +1829,7 @@ dl_main (const ElfW(Phdr) *phdr,
   if (GLRO(dl_use_load_bias) == (ElfW(Addr)) -2)
     GLRO(dl_use_load_bias) = main_map->l_addr == 0 ? -1 : 0;
 
-  /* Set up the program header information for the dynamic linker
-     itself.  It is needed in the dl_iterate_phdr callbacks.  */
-  const ElfW(Ehdr) *rtld_ehdr;
-
-  /* Starting from binutils-2.23, the linker will define the magic symbol
-     __ehdr_start to point to our own ELF header if it is visible in a
-     segment that also includes the phdrs.  If that's not available, we use
-     the old method that assumes the beginning of the file is part of the
-     lowest-addressed PT_LOAD segment.  */
-#ifdef HAVE_EHDR_START
-  extern const ElfW(Ehdr) __ehdr_start __attribute__ ((visibility ("hidden")));
-  rtld_ehdr = &__ehdr_start;
-#else
-  rtld_ehdr = (void *) GL(dl_rtld_map).l_map_start;
-#endif
-  assert (rtld_ehdr->e_ehsize == sizeof *rtld_ehdr);
-  assert (rtld_ehdr->e_phentsize == sizeof (ElfW(Phdr)));
-
-  const ElfW(Phdr) *rtld_phdr = (const void *) rtld_ehdr + rtld_ehdr->e_phoff;
-
-  GL(dl_rtld_map).l_phdr = rtld_phdr;
-  GL(dl_rtld_map).l_phnum = rtld_ehdr->e_phnum;
-
-
-  /* PT_GNU_RELRO is usually the last phdr.  */
-  size_t cnt = rtld_ehdr->e_phnum;
-  while (cnt-- > 0)
-    if (rtld_phdr[cnt].p_type == PT_GNU_RELRO)
-      {
-	GL(dl_rtld_map).l_relro_addr = rtld_phdr[cnt].p_vaddr;
-	GL(dl_rtld_map).l_relro_size = rtld_phdr[cnt].p_memsz;
-	break;
-      }
+  rtld_setup_phdr ();
 
   /* Add the dynamic linker to the TLS list if it also uses TLS.  */
   if (GL(dl_rtld_map).l_tls_blocksize != 0)