From adc997b3d66d1cfa8c15a7dbafdaef239a51b5db Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Wed, 23 Jun 2021 14:01:43 +0200 Subject: [PATCH] x86/fpu: Use copy_xstate_to_uabi_buf() in xfpregs_get() Use the new functionality of copy_xstate_to_uabi_buf() to retrieve the FX state when XSAVE* is in use. This avoids overwriting the FPU state buffer with fpstate_sanitize_xstate() which is error prone and duplicated code. Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Reviewed-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210623121452.901736860@linutronix.de --- arch/x86/kernel/fpu/regset.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c index 783f84dfcd46..ccbe25f6627d 100644 --- a/arch/x86/kernel/fpu/regset.c +++ b/arch/x86/kernel/fpu/regset.c @@ -33,13 +33,18 @@ int xfpregs_get(struct task_struct *target, const struct user_regset *regset, { struct fpu *fpu = &target->thread.fpu; - if (!boot_cpu_has(X86_FEATURE_FXSR)) + if (!cpu_feature_enabled(X86_FEATURE_FXSR)) return -ENODEV; fpu__prepare_read(fpu); - fpstate_sanitize_xstate(fpu); - return membuf_write(&to, &fpu->state.fxsave, sizeof(struct fxregs_state)); + if (!use_xsave()) { + return membuf_write(&to, &fpu->state.fxsave, + sizeof(fpu->state.fxsave)); + } + + copy_xstate_to_uabi_buf(to, &fpu->state.xsave, XSTATE_COPY_FX); + return 0; } int xfpregs_set(struct task_struct *target, const struct user_regset *regset, -- 2.39.5