[COMMITTED 2.34,2.35] hppa: Remove _dl_skip_args usage (BZ# 29165)

[COMMITTED 2.34,2.35] hppa: Remove _dl_skip_args usage (BZ# 29165)

[Adhemerval Zanella]

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>
(cherry picked from commit 6242602273feb8d68cd51cff0ad21b3c8ee11fc6)
---
 NEWS                      |  1 +
 sysdeps/hppa/dl-machine.h | 36 ++++++++++++++----------------------
 2 files changed, 15 insertions(+), 22 deletions(-)

diff --git a/NEWS b/NEWS
index fe37985bc2..fdd46be860 100644
--- a/NEWS
+++ b/NEWS
@@ -101,6 +101,7 @@ The following bugs are resolved with this release:
   [29078] <dlfcn.h> functions unusable during early auditing
   [29097] time: fchmodat does not handle 64 bit time_t for
     AT_SYMLINK_NOFOLLOW
+  [29165] libc: [Regression] broken argv adjustment
   [29203] libc: daemon is not y2038 aware
   [29204] libc: getusershell is not 2038 aware
   [29207] libc: posix_fallocate fallback implementation is not y2038
diff --git a/sysdeps/hppa/dl-machine.h b/sysdeps/hppa/dl-machine.h
index ac66f04418..df6269209f 100644
--- a/sysdeps/hppa/dl-machine.h
+++ b/sysdeps/hppa/dl-machine.h
@@ -374,10 +374,6 @@ 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,	\
@@ -435,12 +431,7 @@ 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"					\
 									\
@@ -450,22 +441,23 @@ 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"				\
-- 
2.34.1