[glibc] s390: Remove _dl_skip_args usage

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=22d8935d1d80c73b564cccde1bcb10cba05bc8d3

commit 22d8935d1d80c73b564cccde1bcb10cba05bc8d3
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Thu May 26 13:13:05 2022 -0300

    s390: Remove _dl_skip_args usage
    
    Since ad43cac44a the generic code already shuffles the argv/envp/auxv
    on the stack to remove the ld.so own arguments and thus _dl_skip_args
    is always 0.   So there is no need to adjust the argc or argv.
    
    Checked on s390x-linux-gnu and s390-linux-gnu.
    
    Reviewed-by: Carlos O'Donell <carlos@redhat.com>

Diff:
---
 sysdeps/s390/s390-32/dl-machine.h | 46 ---------------------------------------
 sysdeps/s390/s390-64/dl-machine.h | 16 --------------
 2 files changed, 62 deletions(-)

diff --git a/sysdeps/s390/s390-32/dl-machine.h b/sysdeps/s390/s390-32/dl-machine.h
index 4392abb355..b69787b0ad 100644
--- a/sysdeps/s390/s390-32/dl-machine.h
+++ b/sysdeps/s390/s390-32/dl-machine.h
@@ -186,52 +186,6 @@ _dl_start_user:\n\
 	# Point %r12 at the GOT.\n\
 	l     %r12,.Ladr0-.Llit(%r13)\n\
 	ar    %r12,%r13\n\
-	# See if we were run as a command with the executable file\n\
-	# name as an extra leading argument.\n\
-	l     %r1,_dl_skip_args@GOT(%r12)\n\
-	l     %r1,0(%r1)	# load _dl_skip_args\n\
-	ltr   %r1,%r1\n\
-	je    4f		# Skip the arg adjustment if there were none.\n\
-	# Get the original argument count.\n\
-	l     %r0,96(%r15)\n\
-	# Subtract _dl_skip_args from it.\n\
-	sr    %r0,%r1\n\
-	# Store back the modified argument count.\n\
-	st    %r0,96(%r15)\n\
-	# Copy argv and envp forward to account for skipped argv entries.\n\
-	# We skipped at least one argument or we would not get here.\n\
-	la    %r6,100(%r15)	# Destination pointer i.e. &argv[0]\n\
-	lr    %r5,%r6\n\
-	lr    %r0,%r1\n\
-	sll   %r0,2\n		# Number of skipped bytes.\n\
-	ar    %r5,%r0		# Source pointer = Dest + Skipped args.\n\
-	# argv copy loop:\n\
-1:	l     %r7,0(%r5)	# Load a word from the source.\n\
-	st    %r7,0(%r6)	# Store the word in the destination.\n\
-	ahi   %r5,4\n\
-	ahi   %r6,4\n\
-	ltr   %r7,%r7\n\
-	jne   1b		# Stop after copying the NULL.\n\
-	# envp copy loop:\n\
-2:	l     %r7,0(%r5)	# Load a word from the source.\n\
-	st    %r7,0(%r6)	# Store the word in the destination.\n\
-	ahi   %r5,4\n\
-	ahi   %r6,4\n\
-	ltr   %r7,%r7\n\
-	jne   2b		# Stop after copying the NULL.\n\
-	# Now we have to zero out the envp entries after NULL to allow\n\
-	# start.S to properly find auxv by skipping zeroes.\n\
-	# zero out loop:\n\
-	lhi   %r7,0\n\
-3:	st    %r7,0(%r6)	# Store zero.\n\
-	ahi   %r6,4		# Advance dest pointer.\n\
-	ahi   %r1,-1		# Subtract one from the word count.\n\
-	ltr   %r1,%r1\n\
-	jne    3b		# Keep copying if the word count is non-zero.\n\
-	# Adjust _dl_argv\n\
-	la    %r6,100(%r15)\n\
-	l     %r1,_dl_argv@GOT(%r12)\n\
-	st    %r6,0(%r1)\n\
 	# The special initializer gets called with the stack just\n\
 	# as the application's entry point will see it; it can\n\
 	# switch stacks if it moves these contents over.\n\
diff --git a/sysdeps/s390/s390-64/dl-machine.h b/sysdeps/s390/s390-64/dl-machine.h
index 7a94b3a7a6..74be0552dc 100644
--- a/sysdeps/s390/s390-64/dl-machine.h
+++ b/sysdeps/s390/s390-64/dl-machine.h
@@ -167,22 +167,6 @@ _dl_start_user:\n\
 	lgr   %r8,%r2\n\
 	# Point %r12 at the GOT.\n\
 	larl  %r12,_GLOBAL_OFFSET_TABLE_\n\
-	# See if we were run as a command with the executable file\n\
-	# name as an extra leading argument.\n\
-	lghi  %r1,_dl_skip_args@GOT\n\
-	lg    %r1,0(%r1,%r12)\n\
-	lgf   %r1,0(%r1)	  # load _dl_skip_args\n\
-	# Get the original argument count.\n\
-	lg    %r0,160(%r15)\n\
-	# Subtract _dl_skip_args from it.\n\
-	sgr   %r0,%r1\n\
-	# Adjust the stack pointer to skip _dl_skip_args words.\n\
-	sllg  %r1,%r1,3\n\
-	agr   %r15,%r1\n\
-	# Set the back chain to zero again\n\
-	xc    0(8,%r15),0(%r15)\n\
-	# Store back the modified argument count.\n\
-	stg   %r0,160(%r15)\n\
 	# The special initializer gets called with the stack just\n\
 	# as the application's entry point will see it; it can\n\
 	# switch stacks if it moves these contents over.\n\