On Fri, Nov 04, 2022 at 03:35:54PM -0700, Rick Edgecombe wrote:
> +#ifdef CONFIG_X86_USER_SHADOW_STACK
> +static inline int write_user_shstk_64(u64 __user *addr, u64 val)
> +{
> + asm_volatile_goto("1: wrussq %[val], (%[addr])\n"
> + _ASM_EXTABLE(1b, %l[fail])
> + :: [addr] "r" (addr), [val] "r" (val)
> + :: fail);
> + return 0;
> +fail:
> + return -EFAULT;
> +}
> +#endif /* CONFIG_X86_USER_SHADOW_STACK */
Why isn't this modelled after put_user() ?
Should you write a 64bit value even if the task receiving a signal is
32bit ?
