On Fri, 2022-12-09 at 19:04 +0200, Mike Rapoport wrote:

quoted

  /*
   * xstateregs_active == regset_fpregs_active. Please refer to the
comment

diff --git a/arch/x86/kernel/fpu/regset.c

b/arch/x86/kernel/fpu/regset.c
index 6d056b68f4ed..00f3d5c9b682 100644

--- a/arch/x86/kernel/fpu/regset.c
+++ b/arch/x86/kernel/fpu/regset.c

@@ -8,6 +8,7 @@
  #include <asm/fpu/api.h>
  #include <asm/fpu/signal.h>
  #include <asm/fpu/regset.h>
+#include <asm/prctl.h>
  
  #include "context.h"
  #include "internal.h"

@@ -174,6 +175,92 @@ int xstateregs_set(struct task_struct *target,

const struct user_regset *regset,
       return ret;
  }
  
+
+#ifdef CONFIG_X86_USER_SHADOW_STACK
+int ssp_active(struct task_struct *target, const struct
user_regset *regset)
+{
+     if (shstk_enabled())

This is not going to work with ptrace as shstk_enabled() checks
current
rather than target.

Oh right, thanks. I can change shstk_enabled() to take a task_struct.