On Thu, Jan 21, 2021 at 10:20:40AM +0100, Ard Biesheuvel wrote: > From: Alex Deucher <alexander.deucher@xxxxxxx> > > commit c241ed2f0ea549c18cff62a3708b43846b84dae3 upstream. > > >From Ard: > > "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." > > Disable support until the code can be properly refactored to support this > properly on aarch64. > > Acked-by: Will Deacon <will@xxxxxxxxxx> > Reported-by: Ard Biesheuvel <ardb@xxxxxxxxxx> > Signed-off-by: Alex Deucher <alexander.deucher@xxxxxxx> > [ardb: backport to v5.10 by reverting c38d444e44badc55 instead] > Acked-by: Alex Deucher <alexander.deucher@xxxxxxx> # v5.10 backport > Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx> > --- > The original commit does not apply cleanly to v5.10, as it reverts a > combination of patches, some of which are not present in v5.10. > > This patch is a straight revert of c38d444e44badc55, which is the only > change that needs to be backed out from v5.10, and amounts to the same > thing as the original mainline commit. Now queued up, thanks. greg k-h
