Re: [PATCH 1/3] xen: common: add ability to enable stack protector

[Julien Grall <julien@xxxxxxx>]

Hi,

Hi Volodymyr,

On 22/11/2024 21:07, Volodymyr Babchuk wrote:
> diff --git a/xen/include/xen/stack_protector.h 
> b/xen/include/xen/stack_protector.h
> new file mode 100644
> index 0000000000..97f1eb5ac0
> --- /dev/null
> +++ b/xen/include/xen/stack_protector.h
> @@ -0,0 +1,30 @@
> +/* SPDX-License-Identifier: GPL-2.0-only */
> +
> +#ifndef XEN__STACK_PROTECTOR_H
> +#define XEN__STACK_PROTECTOR_H
> +
> +#ifdef CONFIG_STACKPROTECTOR
> +
> +#ifndef CONFIG_X86
> +extern unsigned long __stack_chk_guard;
Is this variable meant to change after boot? If not, then can you tag it 
with __ro_after_init?
> +#endif
> +
> +/*
> + * This function should be always inlined. Also it should be called
> + * from a function that never returns.
> + */
> +static inline void boot_stack_chk_guard_setup(void)
> +{
> +       __stack_chk_guard = get_random();
> +       if (BITS_PER_LONG == 64)
> +               __stack_chk_guard |= ((unsigned long)get_random()) << 32;
> +}
> +
> +#else
> +
> +static inline void boot_stack_chk_guard_setup(void) {}
> +
> +#endif /* CONFIG_STACKPROTECTOR  */
> +
> +#endif /* XEN__STACK_PROTECTOR_H */
> +
Cheers,

--
Julien Grall