some arm patches

[Philip Blundell <Philip dot Blundell at pobox dot com>]

Could someone please check these in?

Thanks

p.

2002-12-21  Philip Blundell  <philb@gnu.org>

	* sysdeps/arm/elf/start.S (_start): Optimise a little.  Push stack
	top as seventh arg to __libc_start_main.  
	(Reported by paulnash@wildseed.com.)

	* sysdeps/unix/sysv/linux/arm/clone.S: Small optimisation.

	* sysdeps/unix/sysv/linux/arm/sigcontextinfo.h: Elide
	compatibility cruft when new enough kernel is assumed.

Index: sysdeps/arm/elf/start.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/arm/elf/start.S,v
retrieving revision 1.6
diff -u -p -r1.6 start.S
--- sysdeps/arm/elf/start.S	9 Dec 2002 20:37:20 -0000	1.6
+++ sysdeps/arm/elf/start.S	21 Dec 2002 17:06:05 -0000
@@ -45,26 +45,34 @@
 	.globl _start
 	.type _start,#function
 _start:
+	/* Fetch address of fini */
+	ldr ip, =__libc_csu_fini
+
 	/* Clear the frame pointer since this is the outermost frame.  */
 	mov fp, #0
 
 	/* Pop argc off the stack and save a pointer to argv */
-	ldmfd sp!, {a2}
+	ldr a2, [sp], #4
 	mov a3, sp
 
-	/* Push the last arguments to main() onto the stack */
-	stmfd sp!, {a1}
-	ldr a1, =__libc_csu_fini
-	stmfd sp!, {a1}
+	/* Push stack limit */
+	str a3, [sp, #-4]!
+
+	/* Push rtld_fini */
+	str a1, [sp, #-4]!
 
-	/* Set up the other arguments for main() that go in registers */
+	/* Set up the other arguments in registers */
 	ldr a1, =main
 	ldr a4, =__libc_csu_init
 
-	/* __libc_start_main (main, argc, argv, init, fini, rtld_fini) */
+	/* Push fini */
+	str ip, [sp, #-4]!
+
+	/* __libc_start_main (main, argc, argv, init, fini, rtld_fini, stack_end) */
 
 	/* Let the libc call main and exit with its return code.  */
 	bl __libc_start_main
+
 	/* should never get here....*/
 	bl abort
 
Index: sysdeps/unix/sysv/linux/arm/clone.S
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/unix/sysv/linux/arm/clone.S,v
retrieving revision 1.6
diff -u -p -r1.6 clone.S
--- sysdeps/unix/sysv/linux/arm/clone.S	6 Jul 2001 04:56:13 -0000	1.6
+++ sysdeps/unix/sysv/linux/arm/clone.S	21 Dec 2002 17:06:17 -0000
@@ -1,4 +1,4 @@
-/* Copyright (C) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1996, 1997, 1998, 1999, 2002 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Pat Beirne <patb@corelcomputer.com>
 
@@ -35,10 +35,8 @@ ENTRY(__clone)
 	beq	PLTJMP(syscall_error)
 
 	@ insert the args onto the new stack
-	sub	r1, r1, #8
-	str	r3, [r1, #4]
-	@ save the function pointer as the 0th element
-	str	r0, [r1]
+	str	r3, [r1, #-4]!
+	str	r0, [r1, #-4]!
 
 	@ do the system call
 	@ get flags
Index: sysdeps/unix/sysv/linux/arm/sigcontextinfo.h
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/unix/sysv/linux/arm/sigcontextinfo.h,v
retrieving revision 1.7
diff -u -p -r1.7 sigcontextinfo.h
--- sysdeps/unix/sysv/linux/arm/sigcontextinfo.h	6 Jul 2001 04:56:13 -0000	1.7
+++ sysdeps/unix/sysv/linux/arm/sigcontextinfo.h	21 Dec 2002 17:06:18 -0000
@@ -1,4 +1,4 @@
-/* Copyright (C) 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1999, 2002 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Philip Blundell <philb@gnu.org>, 1999.
 
@@ -18,10 +18,22 @@
    02111-1307 USA.  */
 
 #include <bits/armsigctx.h>
+#include "kernel-features.h"
 
 #define SIGCONTEXT int _a2, int _a3, int _a4, union k_sigcontext
 #define SIGCONTEXT_EXTRA_ARGS _a2, _a3, _a4,
 
+/* The sigcontext structure changed between 2.0 and 2.1 kernels.  On any
+   modern system we should be able to assume that the "new" format will be
+   in use.  */
+#if __LINUX_KERNEL_VERSION > 131328
+
+#define GET_PC(ctx)	((void *) ctx.v21.arm_pc)
+#define GET_FRAME(ctx)	ADVANCE_STACK_FRAME ((void *) ctx.v21.arm_fp)
+#define GET_STACK(ctx)	((void *) ctx.v21.arm_sp)
+
+#else
+
 #define GET_PC(ctx)	((void *)((ctx.v20.magic == SIGCONTEXT_2_0_MAGIC) ? \
 			 ctx.v20.reg.ARM_pc : ctx.v21.arm_pc))
 #define GET_FRAME(ctx)	\
@@ -29,7 +41,11 @@
 			 ctx.v20.reg.ARM_fp : ctx.v21.arm_fp))
 #define GET_STACK(ctx)	((void *)((ctx.v20.magic == SIGCONTEXT_2_0_MAGIC) ? \
 			 ctx.v20.reg.ARM_sp : ctx.v21.arm_sp))
+
+#endif
+
 #define ADVANCE_STACK_FRAME(frm)	\
 			((struct layout *)frm - 1)
+
 #define CALL_SIGHANDLER(handler, signo, ctx) \
   (handler)((signo), SIGCONTEXT_EXTRA_ARGS (ctx))