Re: [PATCH v2 5/7] arm64: ptrace: nofpsimd: Fail FP/SIMD regset operations
From: Suzuki Kuruppassery Poulose
Date: Fri Jan 10 2020 - 13:42:42 EST
On 10/01/2020 15:12, Catalin Marinas wrote:
On Tue, Dec 17, 2019 at 06:34:00PM +0000, Suzuki K Poulose wrote:
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 6771c399d40c..0135b944b8db 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -637,6 +637,9 @@ 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();
I checked the coredump code (fill_thread_core_info) and works correctly
if we return -EINVAL here. But for completeness, we could add an
fpr_active() callback to aarch{32,64}_regsets (x86 does the same).
Sure, makes sense. I have now added fpr_active() hook for the FP
regsets.
Suzuki