Replace AT_EXECFN in auxiliary vectors of programs executed on Android

* exec/exec.c (insert_args, exec_0): On non-MIPS systems, copy
NAME and its length to the loader area.  State that MIPS support
is not yet available (though it will be pending the availability
of a functioning emulator).

* exec/loader-aarch64.s (_start):

* exec/loader-armeabi.s (_start):

* exec/loader-x86.s (_start):

* exec/loader-x86_64.s (_start): Displace auxv, environ, and
argv to create sufficient space for the provided file name, and
copy the file name there.  Replace AT_EXECFN to refer to this
space.

1 files changed, 24 insertions, 1 deletions

diff --git a/exec/exec.c b/exec/exec.c
index b1c9825daff..7a8ef2c3a1a 100644
--- a/exec/exec.c
+++ b/exec/exec.c
@@ -831,7 +831,7 @@ insert_args (struct exec_tracee *tracee, USER_REGS_STRUCT *regs,
   assert (new3 == new + effective_size);
 
   /* And that it is properly aligned.  */
-  assert (!(new3 & (sizeof new3 - 2)));
+  assert (!(new3 & (sizeof new3 - 1)));
 
   /* Now modify the system call argument to point to new +
      text_size.  */
@@ -916,6 +916,9 @@ exec_0 (char *name, struct exec_tracee *tracee,
   program_header program;
   USER_WORD entry, program_entry, offset;
   USER_WORD header_offset;
+#ifndef __mips__
+  USER_WORD name_len, aligned_len;
+#endif /* !__mips__ */
   struct exec_jump_command jump;
 #if defined __mips__ && !defined MIPS_NABI
   int fpu_mode;
@@ -1146,6 +1149,26 @@ exec_0 (char *name, struct exec_tracee *tracee,
           sizeof jump);
   loader_area_used += sizeof jump;
 
+  /* TODO: MIPS support.  */
+#ifndef __mips__
+  /* Copy the length of NAME and NAME itself to the loader area.  */
+  name_len = strlen (name);
+  aligned_len = ((name_len + 1 + sizeof name_len - 1)
+                 & -sizeof name_len);
+  if (sizeof loader_area - loader_area_used
+      < aligned_len + sizeof name_len)
+    goto fail1;
+  memcpy (loader_area + loader_area_used, &name_len, sizeof name_len);
+  loader_area_used += sizeof name_len;
+  memcpy (loader_area + loader_area_used, name, name_len + 1);
+  loader_area_used += name_len + 1;
+
+  /* Properly align the loader area.  */
+  offset = aligned_len - (name_len + 1);
+  while (offset--)
+    loader_area[loader_area_used++] = '\0';
+#endif /* !__mips__ */
+
   /* Close the file descriptor and return the number of bytes
      used.  */