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 6771c39..cd6e5fa 100644 (file)
--- 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
        },