From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <5144DB0F.9050901@xenomai.org> Date: Sat, 16 Mar 2013 21:50:23 +0100 From: Gilles Chanteperdrix MIME-Version: 1.0 References: <5144D3E9.2050205@xenomai.org> <5144D524.4000302@web.de> <5144D5AB.3080004@xenomai.org> <5144D5E3.9050601@web.de> In-Reply-To: <5144D5E3.9050601@web.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] __get_user/__put_user List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Xenomai On 03/16/2013 09:28 PM, Jan Kiszka wrote: > On 2013-03-16 21:27, Gilles Chanteperdrix wrote: >> On 03/16/2013 09:25 PM, Jan Kiszka wrote: >> >>> On 2013-03-16 21:19, Gilles Chanteperdrix wrote: >>>> >>>> Hi, >>>> >>>> xenomai asm-generic/syscall.h defines __xn_put_user/__xn_get_user as >>>> aliases for __put_user/__get_user, which implementation, for the ARM >>>> architecture calls might_fault() which triggers an ipipe_root_only() check. >>>> >>>> So, the question is, what is the best way of avoiding this issue? Remove >>>> the call to might_fault() when compiling with CONFIG_IPIPE enabled? >>>> Define __ipipe_safe_put_user which avoids the call to might_fault() ? >>> >>> Adjust might_fault() in a way that it only considers atomic non-root >>> contexts as problematic. >> >> >> atomic meaning with hardware irqs off? or within an irq handler? This >> requires xenomai... > > Hard irqs off || head domain stalled, I would say. ok, done, thanks. -- Gilles.