Re: [PATCH 3/3] xen: riscv: enable stack protector feature

[oleksii.kurochko@xxxxxxxxx]

On Fri, 2024-11-22 at 21:07 +0000, Volodymyr Babchuk wrote:
> Enable previously added CONFIG_STACK_PROTECTOR feature for RISC-V
> platform. Here we can call boot_stack_chk_guard_setup() in
> start_xen()
> function, because it never returns, so stack protector code will not
> be triggered because of changed canary.
> 
> Signed-off-by: Volodymyr Babchuk <volodymyr_babchuk@xxxxxxxx>
> 
> ---
> 
> I tested this patch for buildability, but didn't verified that Xen
> really boots on RISC-V when this feature is enabled. So I am asking
> RISC-V maintainers to provide feedback on it.
> ---
I've tested on staging and on downstream branches everything is fine:
Tested-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>

~ Oleksii

>  xen/arch/riscv/Kconfig | 1 +
>  xen/arch/riscv/setup.c | 3 +++
>  2 files changed, 4 insertions(+)
> 
> diff --git a/xen/arch/riscv/Kconfig b/xen/arch/riscv/Kconfig
> index 1858004676..1481f23b66 100644
> --- a/xen/arch/riscv/Kconfig
> +++ b/xen/arch/riscv/Kconfig
> @@ -5,6 +5,7 @@ config RISCV
>       select HAS_DEVICE_TREE
>       select HAS_PMAP
>       select HAS_VMAP
> +     select HAS_STACK_PROTECTOR
>  
>  config RISCV_64
>       def_bool y
> diff --git a/xen/arch/riscv/setup.c b/xen/arch/riscv/setup.c
> index e29bd75d7c..cd71748d2c 100644
> --- a/xen/arch/riscv/setup.c
> +++ b/xen/arch/riscv/setup.c
> @@ -7,6 +7,7 @@
>  #include <xen/init.h>
>  #include <xen/mm.h>
>  #include <xen/shutdown.h>
> +#include <xen/stack_protector.h>
>  
>  #include <public/version.h>
>  
> @@ -55,6 +56,8 @@ void __init noreturn start_xen(unsigned long
> bootcpu_id,
>      if ( !boot_fdt_info(device_tree_flattened, dtb_addr) )
>          BUG();
>  
> +    boot_stack_chk_guard_setup();
> +
>      cmdline = boot_fdt_cmdline(device_tree_flattened);
>      printk("Command line: %s\n", cmdline);
>      cmdline_parse(cmdline);