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Date: Tue, 18 Apr 2006 14:57:28 +0200
From: Pavel Machek <pavel@ucw.cz>
To: Jeff Dike <jdike@addtoit.com>
Cc: linux-kernel@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net
Subject: Re: [RFC] PATCH 3/4 - Time virtualization : PTRACE_SYSCALL_MASK
Message-ID: <20060418125728.GA26554@elf.ucw.cz>
References: <200604131720.k3DHKqdr004720@ccure.user-mode-linux.org>
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Hi!

> Add PTRACE_SYSCALL_MASK, which allows system calls to be selectively
> traced.  It takes a bitmask and a length.  A system call is traced
> if its bit is one.  Otherwise, it executes normally, and is
> invisible to the ptracing parent.
> 
> This is not just useful for UML - strace -e could make good use of it as well.

> +	if((current->syscall_mask != NULL) &&

Please put space between if and (.

> @@ -690,6 +693,11 @@ int do_syscall_trace(struct pt_regs *reg
>  	if (!(current->ptrace & PT_PTRACED))
>  		goto out;
>  
> +	if((current->syscall_mask != NULL) && ((long) regs->orig_eax != -1) &&
> +	   !(current->syscall_mask[regs->orig_eax / (8 * sizeof(long))] &
> +	     (1 << (regs->orig_eax % (8 * sizeof(long))))))
> +		goto out;
> +

Same here... and perhaps you can use __get_bit/__set_bit? (this
applies to few more places).

Are you going to fix non-i386, too?
							Pavel
-- 
Thanks for all the (sleeping) penguins.