From mboxrd@z Thu Jan 1 00:00:00 1970 From: imre.deak@nokia.com (Imre Deak) Date: Wed, 13 Jan 2010 18:01:42 +0200 Subject: [RFC PATCH 2/2] ARM: VFP: preserve the HW context when callingsignal handlers In-Reply-To: <1263397782.32612.56.camel@pc1117.cambridge.arm.com> References: <201001041615.26490.siarhei.siamashka@nokia.com> <20100104142549.GF9107@n2100.arm.linux.org.uk> <201001041718.55150.siarhei.siamashka@nokia.com> <20100106174759.GB28921@localhost> <1263397782.32612.56.camel@pc1117.cambridge.arm.com> Message-ID: <20100113160142.GB11726@localhost> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wed, Jan 13, 2010 at 04:49:42PM +0100, ext Catalin Marinas wrote: > On Wed, 2010-01-06 at 17:47 +0000, Imre Deak wrote: > > On Mon, Jan 04, 2010 at 04:18:54PM +0100, Siamashka Siarhei (Nokia-D/Helsinki) wrote: > > > On Monday 04 January 2010 16:25:49 ext Russell King - ARM Linux wrote: > > > > On Mon, Jan 04, 2010 at 04:15:26PM +0200, Siarhei Siamashka wrote: > > > > > On Saturday 13 June 2009 20:04:06 ext Russell King - ARM Linux wrote: > > > > > > - wait for a new patch which includes these other registers and not > > > > > > have any ABI visible changes to contend with > > > > > > > > > > Sorry for bumping this old thread, but what is the current status of > > > > > these patches? > > > > > > > > What happened was that the 2nd option was decided upon, and then the > > > > thread died, and probably everyone forgot about it. > > > > > > > > So, I'm doing exactly what I said I'd do in the second option. I'm just > > > > still waiting some six months on... > > > > > > OK, it's understandable. The issue just got a bit more popular now than it > > > used to be six months ago. > > > > > > > If someone comes up with a tested patch, then its something we should > > > > sort out. > > > > > > Thanks for clarifying the situation. > > > > Jamie, you raised the question of FP emulation in user space; could you > > provide the VFP registers needed for that in addition to the already saved > > ones? With that info I could update the patch so it's acceptable for everyone. > > I think you need to save all of FPSCR, FPEXC, FPINST, FPINST2. The > information in the latter 2 registers is only relevant if corresponding > bits in FPEXC are set (like EX and FP2V). A signal handler could decide > whether to use them or not. Thanks for the info, I'll try to update my patches based on this. --Imre