From: Arnd Bergmann <arnd@arndb.de>
To: linuxppc-embedded@ozlabs.org
Cc: Xupei Liang <tliang@yahoo.com>
Subject: Re: atomic operations in user space
Date: Wed, 23 Aug 2006 00:23:31 +0200 [thread overview]
Message-ID: <200608230023.31402.arnd@arndb.de> (raw)
In-Reply-To: <20060822205024.98433.qmail@web36105.mail.mud.yahoo.com>
Am Tuesday 22 August 2006 22:50 schrieb Xupei Liang:
> #include <asm-ppc/atomic.h>
>
> int main()
> {
> =A0=A0=A0=A0=A0=A0=A0=A0atomic_t atom;
>
> =A0=A0=A0=A0=A0=A0=A0=A0atomic_add(1, &atom);
> =A0=A0=A0=A0=A0=A0=A0=A0return (0);
> }
>
> I am able to compile it and the atomic_add seems to be
> translated into the correct instructions. Can anybody
> please confirm? Thanks.
No, you can't do that, the kernel headers are not generally
working in user space, recent kernel versions protect you
from doing this.
If you don't have a library providing you with atomic operations,
you can copy the inline functions from the kernel, which will
work fine, but require that your app is GPL licensed.
Arnd <><
next prev parent reply other threads:[~2006-08-22 22:28 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-08-22 20:50 atomic operations in user space Xupei Liang
2006-08-22 22:23 ` Arnd Bergmann [this message]
-- strict thread matches above, loose matches on Subject: below --
2006-08-23 19:03 Terry Liang
2006-08-24 10:39 ` Li Yang-r58472
2006-08-24 14:18 ` Brent Cook
2006-08-25 2:33 ` Li Yang-r58472
2006-08-29 0:43 Xupei Liang
2006-08-29 6:43 ` Li Yang-r58472
2006-08-29 8:33 ` Esben Nielsen
2006-08-29 8:54 ` Li Yang-r58472
2006-08-29 9:20 ` Liu Dave-r63238
2006-08-29 9:56 ` Esben Nielsen
2006-08-29 10:05 ` Liu Dave-r63238
2006-08-29 10:52 ` Li Yang-r58472
2006-08-29 11:26 ` Esben Nielsen
2006-08-29 11:30 ` Esben Nielsen
2006-08-29 12:36 ` Brent Cook
2006-08-29 13:37 Li Yang
2006-08-29 16:05 ` Esben Nielsen
2006-08-29 17:00 ` Li Yang
2006-08-30 2:17 Liu Dave-r63238
2006-08-30 2:27 ` Liu Dave-r63238
2006-08-30 2:40 ` Li Yang-r58472
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