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

diff --git a/libc/sysdeps/linux/i386/Makefile b/libc/sysdeps/linux/i386/Makefile
index e29707f..fc13e6f 100644 (file)
--- a/libc/sysdeps/linux/i386/Makefile
+++ b/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)

diff --git a/libc/sysdeps/linux/i386/__syscall_error.c b/libc/sysdeps/linux/i386/__syscall_error.c
new file mode 100644 (file)
index 0000000..de65a1f
--- /dev/null
+++ b/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;
+}

diff --git a/libc/sysdeps/linux/i386/mmap64.S b/libc/sysdeps/linux/i386/mmap64.S
index 42d1bb6..dde3b9a 100644 (file)
--- a/libc/sysdeps/linux/i386/mmap64.S
+++ b/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

diff --git a/libc/sysdeps/linux/i386/syscall.S b/libc/sysdeps/linux/i386/syscall.S
index b65950f..7c49625 100644 (file)
--- a/libc/sysdeps/linux/i386/syscall.S
+++ b/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

diff --git a/libc/sysdeps/linux/i386/vfork.S b/libc/sysdeps/linux/i386/vfork.S
index d9b8ab7..00a2954 100644 (file)
--- a/libc/sysdeps/linux/i386/vfork.S
+++ b/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