From: "David S. Miller" <davem@redhat.com>
To: schwidefsky@de.ibm.com
Cc: torvalds@transmeta.com, dan@debian.org, george@mvista.com,
jim.houston@ccur.com, sfr@canb.auug.org.au,
linux-kernel@vger.kernel.org, anton@samba.org, ak@muc.de,
davidm@hpl.hp.com, ralf@gnu.org, willy@debian.org
Subject: Re: [PATCH] compatibility syscall layer (lets try again)
Date: Mon, 09 Dec 2002 12:18:29 -0800 (PST) [thread overview]
Message-ID: <20021209.121829.34992912.davem@redhat.com> (raw)
In-Reply-To: <OFC1954F5C.20E78677-ONC1256C8A.005E887F@de.ibm.com>
From: "Martin Schwidefsky" <schwidefsky@de.ibm.com>
Date: Mon, 9 Dec 2002 18:16:43 +0100
>Architecture maintainers, can you comment on how easy/hard it is to do the
>same thing on your architectures? I _assume_ it's trivial (akin to the
>three-liner register state change in i386/kernel/signal.c).
For s390/s390x this is actually quite tricky. The system call number is
coded in the instruction, e.g. 0x0aa2 is svc 162 or sys_nanosleep. There
is no register involved that contains the system call number I could
simply change. I either have to change the instruction (no way) or I
have to avoid going back to userspace in this case. This would require
assembler magic in entry.S. Not nice.
Put the magic restart_block syscall at some fixed place in every
user process, change the PC to that. Or, alternatively, put the
restart_block syscall insn on the stack and point the PC at that.
This isn't rocket science :-)
next prev parent reply other threads:[~2002-12-09 20:14 UTC|newest]
Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-12-09 17:16 [PATCH] compatibility syscall layer (lets try again) Martin Schwidefsky
2002-12-09 17:33 ` Linus Torvalds
2002-12-09 20:18 ` David S. Miller [this message]
-- strict thread matches above, loose matches on Subject: below --
2002-12-10 17:17 Martin Schwidefsky
2002-12-10 8:42 Martin Schwidefsky
2002-12-09 18:41 Martin Schwidefsky
2002-12-09 18:52 ` Linus Torvalds
2002-12-10 8:20 ` george anzinger
2002-12-09 17:56 Martin Schwidefsky
2002-12-09 18:20 ` Linus Torvalds
2002-12-10 14:40 ` Keith Owens
2002-12-09 16:58 Mikael Starvik
2002-12-09 17:35 ` Linus Torvalds
2002-12-09 18:46 ` David Mosberger
2002-12-10 0:13 ` Paul Mackerras
2002-12-10 23:11 ` george anzinger
2002-12-04 7:02 Stephen Rothwell
2002-12-04 7:28 ` Stephen Rothwell
2002-12-04 7:30 ` Stephen Rothwell
2002-12-04 7:33 ` Stephen Rothwell
2002-12-04 11:57 ` Pavel Machek
2002-12-04 16:54 ` Linus Torvalds
2002-12-04 16:54 ` David S. Miller
2002-12-04 17:05 ` Linus Torvalds
2002-12-04 19:56 ` george anzinger
2002-12-04 20:07 ` Linus Torvalds
2002-12-04 20:56 ` Daniel Jacobowitz
2002-12-04 22:09 ` David S. Miller
2002-12-04 22:31 ` george anzinger
2002-12-04 22:39 ` David S. Miller
2002-12-04 22:42 ` Linus Torvalds
2002-12-04 23:42 ` Jim Houston
2002-12-05 0:18 ` Linus Torvalds
2002-12-05 2:01 ` george anzinger
2002-12-05 2:51 ` Linus Torvalds
2002-12-05 3:10 ` Andi Kleen
2002-12-05 3:46 ` george anzinger
2002-12-05 4:11 ` Linus Torvalds
2002-12-05 7:10 ` george anzinger
2002-12-05 9:48 ` george anzinger
2002-12-05 15:24 ` Jim Houston
2002-12-05 16:35 ` george anzinger
2002-12-06 0:03 ` Richard Henderson
2002-12-05 17:03 ` Linus Torvalds
2002-12-06 9:17 ` george anzinger
2002-12-06 17:57 ` Linus Torvalds
2002-12-06 19:20 ` Linus Torvalds
2002-12-06 20:18 ` george anzinger
2002-12-06 21:12 ` Linus Torvalds
2002-12-06 21:56 ` Jim Houston
2002-12-06 22:58 ` Linus Torvalds
2002-12-07 2:25 ` george anzinger
2002-12-06 23:08 ` george anzinger
2002-12-08 20:41 ` David S. Miller
2002-12-09 6:18 ` Stephen Rothwell
2002-12-09 15:41 ` Daniel Jacobowitz
2002-12-09 16:48 ` Linus Torvalds
2002-12-09 17:27 ` David Mosberger
2002-12-09 20:22 ` David S. Miller
2002-12-09 17:49 ` Jim Houston
2002-12-09 17:57 ` Linus Torvalds
2002-12-09 23:30 ` Paul Mackerras
2002-12-10 23:07 ` george anzinger
2002-12-11 7:10 ` Daniel Jacobowitz
2002-12-11 8:11 ` george anzinger
2002-12-11 8:26 ` Daniel Jacobowitz
2002-12-10 11:08 ` Jamie Lokier
2002-12-05 2:27 ` Jim Houston
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