Re: [PATCH v6 48/76] x86/entry/64: Add entry code for #VC handler

[Borislav Petkov]

On Mon, Aug 24, 2020 at 10:54:43AM +0200, Joerg Roedel wrote:
> @@ -674,6 +675,56 @@ asmlinkage __visible noinstr struct pt_regs *sync_regs(struct pt_regs *eregs)
>  	return regs;
>  }
>  
> +#ifdef CONFIG_AMD_MEM_ENCRYPT
> +asmlinkage __visible noinstr struct pt_regs *vc_switch_off_ist(struct pt_regs *eregs)
> +{
> +	unsigned long sp, *stack;
> +	struct stack_info info;
> +	struct pt_regs *regs;
> +
> +	/*
> +	 * In the SYSCALL entry path the RSP value comes from user-space - don't
> +	 * trust it and switch to the current kernel stack
> +	 */
> +	if (eregs->ip >= (unsigned long)entry_SYSCALL_64 &&
> +	    eregs->ip <  (unsigned long)entry_SYSCALL_64_safe_stack) {
> +		sp = this_cpu_read(cpu_current_top_of_stack);
> +		goto sync;
> +	}
> +
> +	/*
> +	 * From here on the the RSP value is trusted - more RSP sanity checks
			^^^^^^^

Fished out one valid warning from the confused blabla checkpatch spits out:

WARNING: Possible repeated word: 'the'
#276: FILE: arch/x86/kernel/traps.c:696:
+        * From here on the the RSP value is trusted - more RSP sanity checks

IOW, as I tell other submitters:

Please integrate scripts/checkpatch.pl into your patch creation
workflow. Some of the warnings/errors *actually* make sense.

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette