Peter S. Mazinger writes: use the __syscall_error.c trick to handle setting errno

libc/sysdeps/linux/i386/Makefile

@@ -28,7 +28,7 @@ SSRC=__longjmp.S vfork.S clone.S setjmp.S bsd-setjmp.S \
 	bsd-_setjmp.S syscall.S mmap64.S
 SOBJS=$(patsubst %.S,%.o, $(SSRC))
 
-CSRC=brk.c sigaction.c
+CSRC=brk.c sigaction.c __syscall_error.c
 COBJS=$(patsubst %.c,%.o, $(CSRC))
 
 OBJS=$(SOBJS) $(COBJS)

libc/sysdeps/linux/i386/__syscall_error.c

@@ -0,0 +1,29 @@
+/* Wrapper for setting errno.
+   Copyright (C) 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <errno.h>
+#include <features.h>
+
+/* This routine is jumped to by all the syscall handlers, to stash
+ * an error number into errno.  */
+int attribute_hidden __syscall_error(int err_no)
+{
+	__set_errno(err_no);
+	return -1;
+}

libc/sysdeps/linux/i386/mmap64.S

@@ -65,6 +65,7 @@ mmap64:
 	movl FD(%esp), %edi
 
 	movl $__NR_mmap2, %eax	/* System call number in %eax.  */
+	/* Do the system call trap.  */
 	int $0x80
 
 	/* Restore registers.  */
@@ -75,7 +76,8 @@ mmap64:
 
 	/* If 0 > %eax > -4096 there was an error.  */
 	cmpl $-4095,%eax
-	jae __syscall_error
+	ja __error
+	/* Successful; return the syscall's value.  */
 	ret
 
 	/* This means the offset value is too large.  */
@@ -85,27 +87,11 @@ L_einval:
 	popl %ebx
 	popl %ebp
 	movl $-EINVAL, %eax
-	jmp __syscall_error
-
-
-__syscall_error:
-	negl    %eax
-	pushl   %eax
-#ifdef __PIC__
-	call .Lthere
-.Lthere:
-	popl	%ebx
-	addl	$_GLOBAL_OFFSET_TABLE_+[.- .Lthere  ], %ebx
-	call    __errno_location@PLT
-#else
-	call	__errno_location
-#endif
-	popl	%ecx
-	movl	%ecx, (%eax)
-	xorl	%eax, %eax
-	decl	%eax
+	jmp __error
+
+__error:
+	call	__syscall_error
 
-.Lsize:
-.size mmap64,.Lsize-mmap64
+.size mmap64,.-mmap64
 
 #endif

libc/sysdeps/linux/i386/syscall.S

@@ -20,8 +20,6 @@
  * and things will just work.
  */
 
-#include <features.h>
-	
 .text
 .global syscall
 .type   syscall,%function
@@ -30,49 +28,22 @@ syscall:
 	pushl %edi
 	pushl %esi
 	pushl %ebx
-	movl  36(%esp),%edi;	/* Load the 5 syscall argument registers */
-	movl  32(%esp),%esi;
-	movl  28(%esp),%edx;
-	movl  24(%esp),%ecx;
-	movl  20(%esp),%ebx;
+	movl  36(%esp),%edi	/* Load the 5 syscall argument registers */
+	movl  32(%esp),%esi
+	movl  28(%esp),%edx
+	movl  24(%esp),%ecx
+	movl  20(%esp),%ebx
 	movl  16(%esp),%eax	/* Load syscall number into %eax.  */
-#APP
 	int $0x80
-#NO_APP
-	cmpl $-4095,%eax
-	jbe .Ldone
-
-#ifdef __PIC__
-	call Lhere
-Lhere:
-	popl %ebx
-	addl $_GLOBAL_OFFSET_TABLE_+[.-Lhere],%ebx
-	negl %eax
-	movl %eax,%ecx
-#ifdef __UCLIBC_HAS_THREADS__
-	call __errno_location@PLT
-#else
-	movl errno@GOT(%ebx),%eax
-#endif /* __UCLIBC_HAS_THREADS__ */
-	movl %ecx,(%eax)
-#else
-	negl %eax
-#ifdef __UCLIBC_HAS_THREADS__
-	movl %eax,%ecx
-	call __errno_location
-	movl %ecx,(%eax)
-#else
-	movl %eax,errno
-#endif /* __UCLIBC_HAS_THREADS__ */
-
-#endif /* __PIC__ */
 
-	movl $-1,%eax
-	.p2align 4,,7
-.Ldone:
 	popl %ebx
 	popl %esi
 	popl %edi
-	ret
-.Lsize:
-.size syscall,.Lsize-syscall
+	cmpl $-4095,%eax
+	jae  __error
+	ret			/* Return to caller.  */
+
+__error:
+	call	__syscall_error
+
+.size syscall,.-syscall

libc/sysdeps/linux/i386/vfork.S

@@ -25,28 +25,13 @@ __vfork:
 	int $0x80
 	pushl %ecx
 	cmpl $-4095,%eax
-	jae __syscall_error
+	jae __error
 	ret
 
-__syscall_error:
-	negl    %eax
-	pushl   %eax
-#ifdef __PIC__
-	call .Lthere
-.Lthere:
-	popl	%ebx
-	addl	$_GLOBAL_OFFSET_TABLE_+[.- .Lthere  ], %ebx
-	call    __errno_location@PLT
-#else
-	call	__errno_location
-#endif
-	popl	%ecx
-	movl	%ecx, (%eax)
-	xorl	%eax, %eax
-	decl	%eax
+__error:
+	call	__syscall_error
 
-.Lsize:
-.size __vfork,.Lsize-__vfork
+.size __vfork,.-__vfork
 
 
 .weak vfork ; vfork = __vfork