[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <482027BB.3090705@monstr.eu>
Date: Tue, 06 May 2008 11:41:15 +0200
From: Michal Simek <monstr@...str.eu>
To: Stephen Neuendorffer <stephen.neuendorffer@...inx.com>
CC: John Williams <john.williams@...alogix.com>, monstr@...nam.cz,
linux-kernel@...r.kernel.org, arnd@...db.de,
linux-arch@...r.kernel.org, John Linn <linnj@...inx.com>,
matthew@....cx, will.newton@...il.com, drepper@...hat.com,
microblaze-uclinux@...e.uq.edu.au, grant.likely@...retlab.ca
Subject: Re: [PATCH 07/56] microblaze_v2: Signal support
I hope that conclusion is remove #if 0 from signal.c code.
M
> You're right. (I think I've been staring at this too much today... :)
>
> Steve
>
>> -----Original Message-----
>> From: John Williams [mailto:john.williams@...alogix.com]
>> Sent: Monday, May 05, 2008 5:26 PM
>> To: Stephen Neuendorffer
>> Cc: monstr@...nam.cz; linux-kernel@...r.kernel.org; arnd@...db.de;
> linux-arch@...r.kernel.org; John
>> Linn; matthew@....cx; will.newton@...il.com; drepper@...hat.com;
> microblaze-uclinux@...e.uq.edu.au;
>> grant.likely@...retlab.ca; Michal Simek
>> Subject: RE: [PATCH 07/56] microblaze_v2: Signal support
>>
>> On Mon, 2008-05-05 at 17:13 -0700, Stephen Neuendorffer wrote:
>>> I'm somewhat ignorant about what this code is attempting to do, but
> with
>>> some quick poking around (m68knommu, blackfin) seems to suggest that
>>> other architectures don't do this, while others (v850) have almost
>>> exactly the same code (although they are somewhat smarter and are
>>> careful not to flush the whole cache).
>>>
>>> At the very least, it seems like there is some work in this area
> needed.
>> flush_cache_sigtramp should just invalidate 8 bytes up from the base
>> address of the trampoline. This is just the region on the process
> stack
>> where we insert a kind of call-back back. Writing the opcodes goes
> via
>> the dcache, and so there's a vanishingly small possibility that the
> CPU
>> will get a false hit on on an icache fetch when the code is executed.
>>
>> That was what Michal's patch had when I scanned it yesterday. It
>> certainly won't/shouldn't be invalidating the entire cache.
>>
>> Cheers,
>>
>> John
>>
>>
>
>
>
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists