From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <54DCDC98.5070402@siemens.com> Date: Thu, 12 Feb 2015 18:02:16 +0100 From: Jan Kiszka MIME-Version: 1.0 References: <5491B5E9.4030200@siemens.com> <5491C2CA.7000906@xenomai.org> <5491C179.2000600@siemens.com> <5491CB3F.2050509@xenomai.org> <5491CC27.6080909@siemens.com> <5491D196.3040309@xenomai.org> <54D0E961.4060705@xenomai.org> <54DCD68F.5020005@siemens.com> In-Reply-To: <54DCD68F.5020005@siemens.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Subject: Re: [Xenomai] Mayday mechanism broken on x86-64 - simpler approach feasible? List-Id: Discussions about the Xenomai project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Philippe Gerum , Xenomai On 2015-02-12 17:36, Jan Kiszka wrote: >> As I mentioned earlier, I'd rather fix the MAYDAY implementation for >> x86_64 instead of forking the implementation between MMU-enabled and >> MMU-less architectures, also affecting powerpc, arm and x86_32 in the >> same move. Fortunately, the current implementation allows very specific >> tweaks to be applied on a per-architecture basis. This one fixes the >> issue for Cobalt on x86_64, and could be easily backported to 2.6.x: >> >> http://git.xenomai.org/xenomai-3.git/commit/?h=next&id=6db20901963d634b9786467c711c2ba526db48a2 > > Looks almost good - except for the detail that some bits of the > instruction pointer are lost on return from the syscall (int vs. long > return type). Patches in the making. Will take longer - I need to convert all cobalt syscalls. We have a sleeping bug there, though likely not seen in practice, with syscalls returning values > INT_MAX (size_t...). The problem is that handle_head/root_syscall only forwarded 32-bits so far. Jan -- Siemens AG, Corporate Technology, CT RTC ITP SES-DE Corporate Competence Center Embedded Linux