Revert "Linux: Consolidate auxiliary vector parsing"

This reverts commit 8c8510ab2790039e58995ef3a22309582413d3ff.  The
revert is not perfect because the commit included a bug fix for
_dl_sysdep_start with an empty argv, introduced in commit
2d47fa68628e831a692cba8fc9050cef435afc5e ("Linux: Remove
DL_FIND_ARG_COMPONENTS"), and this bug fix is kept.

The revert is necessary because the reverted commit introduced an
early memset call on aarch64, which leads to crash due to lack of TCB
initialization.

1 files changed, 79 insertions, 30 deletions

diff --git a/sysdeps/unix/sysv/linux/dl-sysdep.c b/sysdeps/unix/sysv/linux/dl-sysdep.c
index 71cf196..5e71704 100644
--- a/sysdeps/unix/sysv/linux/dl-sysdep.c
+++ b/sysdeps/unix/sysv/linux/dl-sysdep.c
@@ -21,12 +21,13 @@
 #include <dl-auxv.h>
 #include <dl-hwcap-check.h>
 #include <dl-osinfo.h>
-#include <dl-parse_auxv.h>
 #include <dl-procinfo.h>
 #include <dl-tunables.h>
 #include <elf.h>
+#include <entry.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <fpu_control.h>
 #include <ldsodefs.h>
 #include <libc-internal.h>
 #include <libintl.h>
@@ -62,20 +63,20 @@ void *_dl_random attribute_relro = NULL;
 # define DL_STACK_END(cookie) ((void *) (cookie))
 #endif
 
-/* Arguments passed to dl_main.  */
-struct dl_main_arguments
+ElfW(Addr)
+_dl_sysdep_start (void **start_argptr,
+		  void (*dl_main) (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
+				   ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv))
 {
-  const ElfW(Phdr) *phdr;
-  ElfW(Word) phnum;
+  const ElfW(Phdr) *phdr = NULL;
+  ElfW(Word) phnum = 0;
   ElfW(Addr) user_entry;
-};
+  ElfW(auxv_t) *av;
+#ifdef NEED_DL_SYSINFO
+  uintptr_t new_sysinfo = 0;
+#endif
 
-/* Separate function, so that dl_main can be called without the large
-   array on the stack.  */
-static void
-_dl_sysdep_parse_arguments (void **start_argptr,
-			    struct dl_main_arguments *args)
-{
+  __libc_stack_end = DL_STACK_END (start_argptr);
   _dl_argc = (intptr_t) *start_argptr;
   _dl_argv = (char **) (start_argptr + 1); /* Necessary aliasing violation.  */
   _environ = _dl_argv + _dl_argc + 1;
@@ -87,26 +88,75 @@ _dl_sysdep_parse_arguments (void **start_argptr,
 	break;
       }
 
-  dl_parse_auxv_t auxv_values = { 0, };
-  _dl_parse_auxv (GLRO(dl_auxv), auxv_values);
+  user_entry = (ElfW(Addr)) ENTRY_POINT;
+  GLRO(dl_platform) = NULL; /* Default to nothing known about the platform.  */
 
-  args->phdr = (const ElfW(Phdr) *) auxv_values[AT_PHDR];
-  args->phnum = auxv_values[AT_PHNUM];
-  args->user_entry = auxv_values[AT_ENTRY];
-}
+  /* NB: Default to a constant CONSTANT_MINSIGSTKSZ.  */
+  _Static_assert (__builtin_constant_p (CONSTANT_MINSIGSTKSZ),
+		  "CONSTANT_MINSIGSTKSZ is constant");
+  GLRO(dl_minsigstacksize) = CONSTANT_MINSIGSTKSZ;
 
-ElfW(Addr)
-_dl_sysdep_start (void **start_argptr,
-		  void (*dl_main) (const ElfW(Phdr) *phdr, ElfW(Word) phnum,
-				   ElfW(Addr) *user_entry, ElfW(auxv_t) *auxv))
-{
-  __libc_stack_end = DL_STACK_END (start_argptr);
-
-  struct dl_main_arguments dl_main_args;
-  _dl_sysdep_parse_arguments (start_argptr, &dl_main_args);
+  for (av = GLRO(dl_auxv); av->a_type != AT_NULL; 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;
+      case AT_SECURE:
+	__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_HWCAP2:
+	GLRO(dl_hwcap2) = (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
+      case AT_SYSINFO_EHDR:
+	GLRO(dl_sysinfo_dso) = (void *) av->a_un.a_val;
+	break;
+      case AT_RANDOM:
+	_dl_random = (void *) av->a_un.a_val;
+	break;
+      case AT_MINSIGSTKSZ:
+	GLRO(dl_minsigstacksize) = av->a_un.a_val;
+	break;
+      DL_PLATFORM_AUXV
+      }
 
   dl_hwcap_check ();
 
+#ifdef NEED_DL_SYSINFO
+  if (new_sysinfo != 0)
+    {
+      /* Only set the sysinfo value if we also have the vsyscall DSO.  */
+      if (GLRO(dl_sysinfo_dso) != 0)
+        GLRO(dl_sysinfo) = new_sysinfo;
+    }
+#endif
+
   __tunables_init (_environ);
 
   /* Initialize DSO sorting algorithm after tunables.  */
@@ -137,9 +187,8 @@ _dl_sysdep_start (void **start_argptr,
   if (__builtin_expect (__libc_enable_secure, 0))
     __libc_check_standard_fds ();
 
-  (*dl_main) (dl_main_args.phdr, dl_main_args.phnum,
-              &dl_main_args.user_entry, GLRO(dl_auxv));
-  return dl_main_args.user_entry;
+  (*dl_main) (phdr, phnum, &user_entry, GLRO(dl_auxv));
+  return user_entry;
 }
 
 void