cheri: change __libc_start_main prototype

The prototype of __libc_start_main is changed to

  void
  __libc_start_main (int main (int, char **, char **, void *),
                     int argc, char **argv, char **envp, void *auxv,
                     void rtld_fini (void), void *sp);

so envp is passed down separately and the unused init, fini args are
dropped.

csu/libc-start.c

@@ -210,11 +210,16 @@ STATIC int LIBC_START_MAIN (int (*main) (int, char **, char **
 					 MAIN_AUXVEC_DECL),
 			    int argc,
 			    char **argv,
+#ifdef LIBC_START_MAIN_ENVP_ARG
+			    char **envp,
+#endif
 #ifdef LIBC_START_MAIN_AUXVEC_ARG
 			    ElfW(auxv_t) *auxvec,
 #endif
+#ifndef LIBC_START_MAIN_NO_INITFINI_ARG
 			    __typeof (main) init,
 			    void (*fini) (void),
+#endif
 			    void (*rtld_fini) (void),
 			    void *stack_end)
      __attribute__ ((noreturn));
@@ -233,15 +238,24 @@ STATIC int LIBC_START_MAIN (int (*main) (int, char **, char **
 STATIC int
 LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
 		 int argc, char **argv,
+#ifdef LIBC_START_MAIN_ENVP_ARG
+		 char **envp,
+#endif
 #ifdef LIBC_START_MAIN_AUXVEC_ARG
 		 ElfW(auxv_t) *auxvec,
 #endif
+#ifndef LIBC_START_MAIN_NO_INITFINI_ARG
 		 __typeof (main) init,
 		 void (*fini) (void),
+#endif
 		 void (*rtld_fini) (void), void *stack_end)
 {
 #ifndef SHARED
+#ifdef LIBC_START_MAIN_ENVP_ARG
+  char **ev = envp;
+#else
   char **ev = &argv[argc + 1];
+#endif
 
   __environ = ev;
 
@@ -358,11 +372,13 @@ LIBC_START_MAIN (int (*main) (int, char **, char ** MAIN_AUXVEC_DECL),
   if (__builtin_expect (GLRO(dl_debug_mask) & DL_DEBUG_IMPCALLS, 0))
     GLRO(dl_debug_printf) ("\ninitialize program: %s\n\n", argv[0]);
 
+#ifndef LIBC_START_MAIN_NO_INITFINI_ARG
   if (init != NULL)
     /* This is a legacy program which supplied its own init
        routine.  */
     (*init) (argc, argv, __environ MAIN_AUXVEC_PARAM);
   else
+#endif
     /* This is a current program.  Use the dynamic segment to find
        constructors.  */
     call_init (argc, argv, __environ);

sysdeps/aarch64/morello/start.c

@@ -136,11 +136,10 @@ apply_rel (uintptr_t base, uintptr_t start, uintptr_t end)
 }
 #endif /* !SHARED */
 
-int main (int argc, char **argv);
+int main (int argc, char **argv, char **envp, void *auxv);
 
-void __libc_start_main (int main (int, char **),
+void __libc_start_main (int main (int, char **, char **, void *),
-			int argc, char **argv,
+			int argc, char **argv, char **envp, void *auxv,
-			void *init, void *fini,
 			void rtld_fini (void), void *sp);
 
 void
@@ -161,7 +160,11 @@ __real_start (void rtld_fini (void), uintptr_t *sp)
 
   int argc = *sp;
   char **argv = (char **) (sp + 1);
-  __libc_start_main (main, argc, argv, 0, 0, rtld_fini, sp);
+  char **envp = argv + argc + 1;
+  char **p = envp;
+  while (*p) p++;
+  void *auxv = p + 1;
+  __libc_start_main (main, argc, argv, envp, auxv, rtld_fini, sp);
   __builtin_trap ();
 }
 

sysdeps/unix/sysv/linux/aarch64/morello/libc-start.c

@@ -0,0 +1,32 @@
+/* Override csu/libc-start.c on Morello.
+   Copyright (C) 2017-2022 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, see
+   <https://www.gnu.org/licenses/>.  */
+
+#ifndef SHARED
+# include <ldsodefs.h>
+# include <cpu-features.c>
+
+extern struct cpu_features _dl_aarch64_cpu_features;
+
+# define ARCH_INIT_CPU_FEATURES() init_cpu_features (&_dl_aarch64_cpu_features)
+#endif
+
+#define LIBC_START_MAIN_ENVP_ARG
+#define LIBC_START_MAIN_AUXVEC_ARG
+#define LIBC_START_MAIN_NO_INITFINI_ARG
+#define MAIN_AUXVEC_ARG
+#include <csu/libc-start.c>