arm64: cpufeature: correctly handle MRS to XZR
authorMark Rutland <mark.rutland@arm.com>
Thu, 9 Feb 2017 15:19:20 +0000 (15:19 +0000)
committerWill Deacon <will.deacon@arm.com>
Wed, 15 Feb 2017 12:20:29 +0000 (12:20 +0000)
commit521c646108ed199d19c5c73978aaca3e18ca8f81
tree1ec326a30049bf907bd669bbc3c69cb3acbec7c9
parent8b6e70fccff27121430114b4507f0adfb790752f
arm64: cpufeature: correctly handle MRS to XZR

In emulate_mrs() we may erroneously write back to the user SP rather
than XZR if we trap an MRS instruction where Xt == 31.

Use the new pt_regs_write_reg() helper to handle this correctly.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Fixes: 77c97b4ee21290f5 ("arm64: cpufeature: Expose CPUID registers by emulation")
Cc: Andre Przywara <andre.przywara@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arch/arm64/kernel/cpufeature.c