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From: "H. Peter Anvin" <hpa@zytor.com>
To: Vaibhav Nagarnaik <vnagarnaik@google.com>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	Frederic Weisbecker <fweisbec@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, David Sharp <dhsharp@google.com>,
	Justin Teravest <teravest@google.com>,
	Laurent Chavey <chavey@google.com>,
	x86@kernel.org, linux-kernel@vger.kernel.org,
	Michael Davidson <md@google.com>
Subject: Re: [PATCH 2/6] trace: add support for 32 bit compat syscalls on x86_64
Date: Mon, 26 Mar 2012 21:49:46 -0700	[thread overview]
Message-ID: <4F7146EA.1030305@zytor.com> (raw)
In-Reply-To: <1332787168-20457-3-git-send-email-vnagarnaik@google.com>

On 03/26/2012 11:39 AM, Vaibhav Nagarnaik wrote:
> +/*
> + * syscall metadata for 32 bit compatible system calls
> + *
> + * The metadata entries are in the same order as the system call table
> + * but this is just to make it easier to check them for completeness
> + * and correctness.
> + */
> +
> +COMPAT_SYSCALL_METADATA0(restart_syscall)
> +COMPAT_SYSCALL_METADATA1(exit, int, error_code)
   [...]
> +COMPAT_SYSCALL_METADATA5(recvmmsg, int, fd, struct mmsghdr __user *, mmsg, unsigned int, vlen, unsigned int, flags, struct timespec __user *, timeout)

> +/*
> + * This is truly horrible.

Yes, it is.  How on Earth do you expect the above to ever be maintained?

> + *
> + * There is no header file that defines a *complete* set of 32 bit system
> + * call numbers (unistd_32.h only defines ones that are currently exported
> + * to user space and omits lots of old system calls that are still implemented
> + * by the kernel.

> + * There is also no table that can be used to map a system call number into
> + * the canonical name of that system call.

arch/x86/syscalls has all of those.  If it's not in there, it doesn't
exist, because that's where the system call table comes from.

	-hpa

  reply	other threads:[~2012-03-27  4:50 UTC|newest]

Thread overview: 29+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-03-26 18:39 [PATCH 0/6] Enhance and speed up syscall tracing Vaibhav Nagarnaik
2012-03-26 18:39 ` [PATCH 1/6] trace: syscalls.h - cleanup and simplify SYSCALL_METADATA() Vaibhav Nagarnaik
2012-03-26 18:39 ` [PATCH 2/6] trace: add support for 32 bit compat syscalls on x86_64 Vaibhav Nagarnaik
2012-03-27  4:49   ` H. Peter Anvin [this message]
2012-03-28 21:10     ` Vaibhav Nagarnaik
2012-03-28 21:11       ` Vaibhav Nagarnaik
2012-03-28 23:00         ` Vaibhav Nagarnaik
2012-03-26 18:39 ` [PATCH 3/6] trace: Refactor ftrace syscall macros to make them more readable Vaibhav Nagarnaik
2012-03-26 18:39 ` [PATCH 4/6] trace: trace syscall in its handler not from ptrace handler Vaibhav Nagarnaik
2012-03-27  5:00   ` H. Peter Anvin
2012-03-28 18:23     ` Vaibhav Nagarnaik
2012-03-29  2:43       ` H. Peter Anvin
2012-03-29  2:59         ` Steven Rostedt
2012-03-29  3:15           ` H. Peter Anvin
2012-03-29  3:02         ` Vaibhav Nagarnaik
2012-03-29  3:16           ` H. Peter Anvin
2012-03-29  6:20           ` Ingo Molnar
2012-03-29 19:02             ` Vaibhav Nagarnaik
2012-03-29 19:12               ` H. Peter Anvin
2012-03-29 19:43                 ` Vaibhav Nagarnaik
2012-03-29 20:06                   ` H. Peter Anvin
2012-03-29 22:40                     ` David Sharp
2012-03-29 22:44                       ` H. Peter Anvin
2012-03-30 12:06                       ` Frederic Weisbecker
2012-03-30 11:57                     ` Frederic Weisbecker
2012-03-29 22:44                 ` David Sharp
2012-03-29 22:48                   ` H. Peter Anvin
2012-03-26 18:39 ` [PATCH 5/6] trace: raw_syscalls: Mark compat syscalls in the MSB of the syscall number Vaibhav Nagarnaik
2012-03-26 18:39 ` [PATCH 6/6] trace: get rid of the enabled_*_syscalls bitmaps Vaibhav Nagarnaik

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