Re: [PATCH] [RFC]arm64:Mark __stack_chk_guard as __ro_after_init

From: Russell King (Oracle)
Date: Tue Sep 14 2021 - 05:58:59 EST


On Tue, Sep 14, 2021 at 05:44:02PM +0800, Dan Li wrote:
> __stack_chk_guard is setup once while init stage and never changed
> after that.
>
> Although the modification of this variable at runtime will usually
> cause the kernel to crash (so dose the attacker), it should be marked
> as _ro_after_init, and it should not affect performance if it is
> placed in the ro_after_init section.
>
> This should also be the case on the ARM platform, or am I missing
> something?

I don't see why it can't be - we only write to it in
boot_init_stack_canary(), same as ARM64.

--
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!