From: Kasper Dupont <kasperd@daimi.au.dk>
To: Robert Love <rml@tech9.net>
Cc: marcelo@conectiva.com.br, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] 2.4: introduce get_cpu() and put_cpu()
Date: Sun, 06 Oct 2002 22:36:14 +0200 [thread overview]
Message-ID: <3DA09EBE.D9E2E148@daimi.au.dk> (raw)
In-Reply-To: 1033933547.743.4472.camel@phantasy
Robert Love wrote:
>
> diff -urN linux-2.4.20-pre9/arch/i386/kernel/ioport.c linux/arch/i386/kernel/ioport.c
> --- linux-2.4.20-pre9/arch/i386/kernel/ioport.c 2002-10-06 14:58:01.000000000 -0400
> +++ linux/arch/i386/kernel/ioport.c 2002-10-06 15:21:04.000000000 -0400
> @@ -55,12 +55,15 @@
> asmlinkage int sys_ioperm(unsigned long from, unsigned long num, int turn_on)
> {
> struct thread_struct * t = ¤t->thread;
> - struct tss_struct * tss = init_tss + smp_processor_id();
> + struct tss_struct * tss;
>
> if ((from + num <= from) || (from + num > IO_BITMAP_SIZE*32))
> return -EINVAL;
> if (turn_on && !capable(CAP_SYS_RAWIO))
> return -EPERM;
> +
> + tss = init_tss + get_cpu();
> +
> /*
> * If it's the first ioperm() call in this thread's lifetime, set the
> * IO bitmap up. ioperm() is much less timing critical than clone(),
To me it really looks like you are missing a put_cpu() call somewhere.
I know it is a no-op, but since you intend to show how to use it, I
it really ought to be there.
Does this look right?
diff -Nur linux.old/arch/i386/kernel/ioport.c linux.new/arch/i386/kernel/ioport.c
--- linux.old/arch/i386/kernel/ioport.c Sun Oct 6 22:33:22 2002
+++ linux.new/arch/i386/kernel/ioport.c Sun Oct 6 22:33:53 2002
@@ -87,6 +87,8 @@
set_bitmap(t->io_bitmap, from, num, !turn_on);
set_bitmap(tss->io_bitmap, from, num, !turn_on);
+ put_cpu();
+
return 0;
}
--
Kasper Dupont -- der bruger for meget tid på usenet.
For sending spam use mailto:aaarep@daimi.au.dk
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next prev parent reply other threads:[~2002-10-06 20:30 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2002-10-06 19:45 [PATCH] 2.4: introduce get_cpu() and put_cpu() Robert Love
2002-10-06 20:36 ` Kasper Dupont [this message]
2002-10-06 21:08 ` Robert Love
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