On Wed, 16 Dec 2020 at 23:26, Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: > > On Wed, 16 Dec 2020 at 19:00, Alex Deucher <alexdeucher@xxxxxxxxx> wrote: > > > > On Mon, Dec 14, 2020 at 12:53 PM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote: > > > > > > This reverts commit c38d444e44badc557cf29fdfdfb823604890ccfa. > > > > > > Simply disabling -mgeneral-regs-only left and right is risky, given that > > > the standard AArch64 ABI permits the use of FP/SIMD registers anywhere, > > > and GCC is known to use SIMD registers for spilling, and may invent > > > other uses of the FP/SIMD register file that have nothing to do with the > > > floating point code in question. Note that putting kernel_neon_begin() > > > and kernel_neon_end() around the code that does use FP is not sufficient > > > here, the problem is in all the other code that may be emitted with > > > references to SIMD registers in it. > > > > > > So the only way to do this properly is to put all floating point code in > > > a separate compilation unit, and only compile that unit with > > > -mgeneral-regs-only. But perhaps the use of floating point here is > > > something that should be reconsidered entirely. > > > > > > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > > > Cc: Will Deacon <will@xxxxxxxxxx> > > > Cc: Dave Martin <dave.martin@xxxxxxx> > > > Cc: Rob Herring <robh@xxxxxxxxxx> > > > Cc: Leo Li <sunpeng.li@xxxxxxx> > > > Cc: Alex Deucher <alexander.deucher@xxxxxxx> > > > Cc: "Christian König" <christian.koenig@xxxxxxx> > > > Cc: David Airlie <airlied@xxxxxxxx> > > > Cc: Daniel Vetter <daniel@xxxxxxxx> > > > Cc: Daniel Kolesa <daniel@xxxxxxxxxxxxx> > > > Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx > > > Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx > > > Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> > > > > Can rebase this on Linus' master branch? There were a number of new > > asics added which copy pasted the ARM64 support. > > > > Not sure what you are asking me here. Reverting commit c38d444e44badc5 > on top of mainline is not going to fix the other code that was added. > Or are you asking me to go and find the patches (how many?) that added > new ASICs and fix them for arm64? > > Note that this code is critically broken, as it may corrupt user > process state arbitrarily. So if new code was added that contains the > same bug, it should be reverted so that the respective authors can fix > it and resubmit. > Is this simply about dropping the newly added references to $(dml_rcflags) from the Makefile? Because that is quite trivial ... _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
