The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c9d66999f064947e6b577ceacc1eb2fbca6a8d3c Mon Sep 17 00:00:00 2001
From: Suzuki K Poulose suzuki.poulose@arm.com Date: Mon, 13 Jan 2020 23:30:21 +0000 Subject: [PATCH] arm64: ptrace: nofpsimd: Fail FP/SIMD regset operations
When fp/simd is not supported on the system, fail the operations of FP/SIMD regsets.
Fixes: 82e0191a1aa11abf ("arm64: Support systems without FP/ASIMD") Cc: Will Deacon will@kernel.org Cc: Mark Rutland mark.rutland@arm.com Reviewed-by: Ard Biesheuvel ardb@kernel.org Reviewed-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Suzuki K Poulose suzuki.poulose@arm.com Signed-off-by: Will Deacon will@kernel.org
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 6771c399d40c..cd6e5fa48b9c 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -615,6 +615,13 @@ static int gpr_set(struct task_struct *target, const struct user_regset *regset, return 0; }
+static int fpr_active(struct task_struct *target, const struct user_regset *regset) +{ + if (!system_supports_fpsimd()) + return -ENODEV; + return regset->n; +} + /* * TODO: update fp accessors for lazy context switching (sync/flush hwstate) */ @@ -637,6 +644,9 @@ static int fpr_get(struct task_struct *target, const struct user_regset *regset, unsigned int pos, unsigned int count, void *kbuf, void __user *ubuf) { + if (!system_supports_fpsimd()) + return -EINVAL; + if (target == current) fpsimd_preserve_current_state();
@@ -676,6 +686,9 @@ static int fpr_set(struct task_struct *target, const struct user_regset *regset, { int ret;
+ if (!system_supports_fpsimd()) + return -EINVAL; + ret = __fpr_set(target, regset, pos, count, kbuf, ubuf, 0); if (ret) return ret; @@ -1134,6 +1147,7 @@ static const struct user_regset aarch64_regsets[] = { */ .size = sizeof(u32), .align = sizeof(u32), + .active = fpr_active, .get = fpr_get, .set = fpr_set }, @@ -1348,6 +1362,9 @@ static int compat_vfp_get(struct task_struct *target, compat_ulong_t fpscr; int ret, vregs_end_pos;
+ if (!system_supports_fpsimd()) + return -EINVAL; + uregs = &target->thread.uw.fpsimd_state;
if (target == current) @@ -1381,6 +1398,9 @@ static int compat_vfp_set(struct task_struct *target, compat_ulong_t fpscr; int ret, vregs_end_pos;
+ if (!system_supports_fpsimd()) + return -EINVAL; + uregs = &target->thread.uw.fpsimd_state;
vregs_end_pos = VFP_STATE_SIZE - sizeof(compat_ulong_t); @@ -1438,6 +1458,7 @@ static const struct user_regset aarch32_regsets[] = { .n = VFP_STATE_SIZE / sizeof(compat_ulong_t), .size = sizeof(compat_ulong_t), .align = sizeof(compat_ulong_t), + .active = fpr_active, .get = compat_vfp_get, .set = compat_vfp_set },