vm86 system call update

vm86 system call update

[Roland McGrath]

Linux/i386 deprecated the old vm86 system call number and added a new one
that takes different parameters, a good while ago now I gather.  This adds
a new stub for it with the right prototype, while preserving binary
compatibility with the old stub.

Ok?


2003-12-02  Roland McGrath  <roland@redhat.com>

	* sysdeps/unix/sysv/linux/i386/syscalls.list: Turn vm86 into vm86old
	for vm86@GLIBC_2.0 version.  Add new vm86@GLIBC_2.3.3.
	* sysdeps/unix/sysv/linux/i386/Versions (libc: GLIBC_2.3.3): Add vm86.
	* sysdeps/unix/sysv/linux/i386/sys/vm86.h: Update vm86 prototype.

Index: sysdeps/unix/sysv/linux/i386/Versions
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/unix/sysv/linux/i386/Versions,v
retrieving revision 1.15
diff -b -p -u -r1.15 Versions
--- sysdeps/unix/sysv/linux/i386/Versions	22 Aug 2003 18:10:45 -0000	1.15
+++ sysdeps/unix/sysv/linux/i386/Versions	2 Dec 2003 23:48:05 -0000
@@ -34,7 +34,11 @@ libc {
     versionsort64;
   }
   GLIBC_2.3.3 {
+    # p*
     posix_fadvise64; posix_fallocate64;
+
+    # v*
+    vm86;
   }
   GLIBC_PRIVATE {
     __modify_ldt;
Index: sysdeps/unix/sysv/linux/i386/syscalls.list
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/unix/sysv/linux/i386/syscalls.list,v
retrieving revision 1.17
diff -b -p -u -r1.17 syscalls.list
--- sysdeps/unix/sysv/linux/i386/syscalls.list	2 Sep 2003 08:41:12 -0000	1.17
+++ sysdeps/unix/sysv/linux/i386/syscalls.list	2 Dec 2003 23:48:05 -0000
@@ -1,7 +1,8 @@
 # File name	Caller	Syscall name	Args	Strong name	Weak names
 
 modify_ldt	EXTRA	modify_ldt	i:ipi	__modify_ldt	modify_ldt
-vm86		-	vm86		i:p	__vm86		vm86
+vm86old		EXTRA	vm86old		i:p	__vm86old	vm86@GLIBC_2.0
+vm86		-	vm86		i:ip	__vm86		vm86@GLIBC_2.3.3
 oldgetrlimit	EXTRA	getrlimit	i:ip	__old_getrlimit	getrlimit@GLIBC_2.0
 oldsetrlimit	EXTRA	setrlimit	i:ip	__old_setrlimit	setrlimit@GLIBC_2.0
 time		-	time		Ei:p	time
Index: sysdeps/unix/sysv/linux/i386/sys/vm86.h
===================================================================
RCS file: /cvs/glibc/libc/sysdeps/unix/sysv/linux/i386/sys/vm86.h,v
retrieving revision 1.5
diff -b -p -u -r1.5 vm86.h
--- sysdeps/unix/sysv/linux/i386/sys/vm86.h	6 Jul 2001 04:56:17 -0000	1.5
+++ sysdeps/unix/sysv/linux/i386/sys/vm86.h	2 Dec 2003 23:48:05 -0000
@@ -1,4 +1,4 @@
-/* Copyright (C) 1996, 1999 Free Software Foundation, Inc.
+/* Copyright (C) 1996, 1999, 2003 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
@@ -27,7 +27,8 @@
 __BEGIN_DECLS
 
 /* Enter virtual 8086 mode.  */
-extern int vm86 (struct vm86_struct *__info) __THROW;
+extern int vm86 (unsigned long int __subfunction,
+		 struct vm86plus_struct *__info) __THROW;
 
 __END_DECLS
 

Re: vm86 system call update

[Ulrich Drepper]

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Roland McGrath wrote:

>    GLIBC_2.3.3 {
> +    # p*
>      posix_fadvise64; posix_fallocate64;
> +
> +    # v*
> +    vm86;

Should be 2.3.4.



> -vm86		-	vm86		i:p	__vm86		vm86
> +vm86old		EXTRA	vm86old		i:p	__vm86old	vm86@GLIBC_2.0
> +vm86		-	vm86		i:ip	__vm86		vm86@GLIBC_2.3.3

This generates wrong code for very old kernels which name have no
vm86old (and name the old version vm86).  We can bump the minimum kernel
requirement, I'd have no problem with that.

- -- 
➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖
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Re: vm86 system call update

[Jakub Jelinek]

On Tue, Dec 02, 2003 at 04:04:48PM -0800, Ulrich Drepper wrote:
> > -vm86		-	vm86		i:p	__vm86		vm86
> > +vm86old		EXTRA	vm86old		i:p	__vm86old	vm86@GLIBC_2.0
> > +vm86		-	vm86		i:ip	__vm86		vm86@GLIBC_2.3.3
> 
> This generates wrong code for very old kernels which name have no
> vm86old (and name the old version vm86).  We can bump the minimum kernel
> requirement, I'd have no problem with that.

That is only about the kernel headers you compile glibc against.
I doubt glibc would build against say 2.2.x kernel headers but I see
no reason why it shouldn't work on 2.2.5 kernel.

	Jakub

Re: vm86 system call update

[Ulrich Drepper]

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Jakub Jelinek wrote:

> That is only about the kernel headers you compile glibc against.

Of course.  But nominally we still support 2.0.x kernels, even for
compiling.  Nobody tried it, of course.  Bumping the compile-time
requirement to 2.2.SOMETHING should be OK.

- -- 
➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖
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Re: vm86 system call update

[Roland McGrath]

> -----BEGIN PGP SIGNED MESSAGE-----
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> 
> Roland McGrath wrote:
> 
> >    GLIBC_2.3.3 {
> > +    # p*
> >      posix_fadvise64; posix_fallocate64;
> > +
> > +    # v*
> > +    vm86;
> 
> Should be 2.3.4.

No, there has been no GNU C Library 2.3.3 release yet.

Re: vm86 system call update

[Ulrich Drepper]

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Roland McGrath wrote:

> No, there has been no GNU C Library 2.3.3 release yet.

There has.  Face it.

- -- 
➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖
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Re: vm86 system call update

[Roland McGrath]

> This generates wrong code for very old kernels which name have no
> vm86old (and name the old version vm86).  We can bump the minimum kernel
> requirement, I'd have no problem with that.

Does anyone know off hand with which Linux kernel version the change came in?

Re: vm86 system call update

[Steven Munroe]

Ulrich Drepper writes:

 > Roland McGrath wrote:
 >
 > > No, there has been no GNU C Library 2.3.3 release yet.
 >
 > There has.  Face it.

So which is it? To add VMX support to powerpc64 I need to version 
setjmp/longjmp and [get | make | set | swap]context. More specifically I 
need to be backward compatible to what shipped in RHEL 3. On my resently 
  installed RHEL 3 GA system I see /lib64/libc-2.3.2.so. But when I run:

readelf -a /lib64/libc-2.3.2.so | grep 'GLIBC_2\.3\.'

I see a significant number of *@@GLIBC_2.3.3 symbols. For example:

     74: 0000000000127484    60 FUNC    GLOBAL DEFAULT   10 
.gnu_dev_makedev@@GLIBC_2.3.3
     94: 000000000014b7e4    64 FUNC    GLOBAL DEFAULT   10 
.inet6_option_init@@GLIBC_2.3.3

So is GLIBC_2.3.3 (effectively) released? And any ABI changes need to be 
  targeted for GLIBC_2.3.4?