hppa: Remove _dl_skip_args usage (BZ# 29165)

Different than other architectures, hppa creates an unrelated stack
frame where ld.so argc/argv adjustments done by ad43cac44a6860eaefc
is not done on the argc/argv saved/restore by _dl_start_user.

Instead load _dl_argc and _dl_argv directlty instead of adjust them
using _dl_skip_args value.

Checked on hppa-linux-gnu.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

diff --git a/sysdeps/hppa/dl-machine.h b/sysdeps/hppa/dl-machine.h
index 8c0ca32fc6031bce8da4760b82fe17dc016a1dc4..c865713be1e3f8e0430bbb35c8db7ebe3e7a6abf 100644 (file)
--- a/sysdeps/hppa/dl-machine.h
+++ b/sysdeps/hppa/dl-machine.h
@@ -354,10 +354,6 @@ asm (                                                                      \
 "_start:\n"                                                            \
        /* The kernel does not give us an initial stack frame. */       \
 "      ldo     64(%sp),%sp\n"                                          \
-       /* Save the relevant arguments (yes, those are the correct      \
-          registers, the kernel is weird) in their stack slots. */     \
-"      stw     %r25,-40(%sp)\n" /* argc */                             \
-"      stw     %r24,-44(%sp)\n" /* argv */                             \
                                                                        \
        /* We need the LTP, and we need it now.                         \
           $PIC_pcrel$0 points 8 bytes past the current instruction,    \
@@ -415,12 +411,7 @@ asm (                                                                      \
          So, obviously, we can't just pass %sp to _dl_start.  That's   \
          okay, argv-4 will do just fine.                               \
                                                                        \
-         The pleasant part of this is that if we need to skip          \
-         arguments we can just decrement argc and move argv, because   \
-         the stack pointer is utterly unrelated to the location of     \
-         the environment and argument vectors. */                      \
-                                                                       \
-       /* This is always within range so we'll be okay. */             \
+         This is always within range so we'll be okay. */              \
 "      bl      _dl_start,%rp\n"                                        \
 "      ldo     -4(%r24),%r26\n"                                        \
                                                                        \
@@ -430,22 +421,23 @@ asm (                                                                     \
        /* Save the entry point in %r3. */                              \
 "      copy    %ret0,%r3\n"                                            \
                                                                        \
-       /* See if we were called as a command with the executable file  \
-          name as an extra leading argument. */                        \
-"      addil   LT'_dl_skip_args,%r19\n"                                \
-"      ldw     RT'_dl_skip_args(%r1),%r20\n"                           \
-"      ldw     0(%r20),%r20\n"                                         \
-                                                                       \
-"      ldw     -40(%sp),%r25\n"        /* argc */                      \
-"      comib,= 0,%r20,.Lnofix\n"       /* FIXME: Mispredicted branch */\
-"      ldw     -44(%sp),%r24\n"        /* argv (delay slot) */         \
+       /* The loader adjusts argc, argv, env, and the aux vectors      \
+          directly on the stack to remove any arguments used for       \
+          direct loader invocation.  Thus, argc and argv must be       \
+          reloaded from from _dl_argc and _dl_argv.  */                \
                                                                        \
-"      sub     %r25,%r20,%r25\n"                                       \
+       /* Load argc from _dl_argc.  */                                 \
+"      addil   LT'_dl_argc,%r19\n"                                     \
+"      ldw     RT'_dl_argc(%r1),%r20\n"                                \
+"      ldw     0(%r20),%r25\n"                                         \
 "      stw     %r25,-40(%sp)\n"                                        \
-"      sh2add  %r20,%r24,%r24\n"                                       \
+                                                                       \
+       /* Same for argv with _dl_argv.  */                             \
+"      addil   LT'_dl_argv,%r19\n"                                     \
+"      ldw     RT'_dl_argv(%r1),%r20\n"                                \
+"      ldw     0(%r20),%r24\n"                                         \
 "      stw     %r24,-44(%sp)\n"                                        \
                                                                        \
-".Lnofix:\n"                                                           \
        /* Call _dl_init(main_map, argc, argv, envp). */                \
 "      addil   LT'_rtld_local,%r19\n"                                  \
 "      ldw     RT'_rtld_local(%r1),%r26\n"                             \