Re: [PATCH v2 4/4] xen: riscv: enable stack protector feature

[oleksii.kurochko@xxxxxxxxx]

On Mon, 2024-12-02 at 09:12 +0100, Jan Beulich wrote:
> On 30.11.2024 02:10, 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>
> > Tested-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
> 
> Isn't this premature? For ...
> 
> > @@ -57,6 +58,8 @@ void __init noreturn start_xen(unsigned long
> > bootcpu_id,
> >      if ( !boot_fdt_info(device_tree_flattened, dtb_addr) )
> >          BUG();
> >  
> > +    boot_stack_chk_guard_setup();
> 
> ... this function's use of get_random(), either arch_get_random()
> needs
> to be implemented, or (as Julien also pointed out for Arm64) NOW()
> needs
> to work. Yet get_s_time() presently expands to just BUG_ON(). Given
> this
> it's not even clear to me how Oleksii managed to actually test this.
I will double check that but it worked for me ( I didn't face BUG_ON()
).

~ Oleksii