svn commit: r337754 - head/sys/x86/x86

[Rodney W. Grimes]

[ Charset UTF-8 unsupported, converting... ]
> Author: markj
> Date: Tue Aug 14 14:02:53 2018
> New Revision: 337754
> URL: https://svnweb.freebsd.org/changeset/base/337754
> 
> Log:
>   Don't use memcpy() in the early microcode loading code.
>   
>   At some point memcpy() may be an ifunc, ifunc resolution cannot be done
>   until CPU identification has been performed, and CPU identification must
>   be done after loading any microcode updates.

Could you please add a comment so that someone does not undo this?

>   
>   X-MFC with:	r337715
>   Sponsored by:	The FreeBSD Foundation
> 
> Modified:
>   head/sys/x86/x86/ucode.c
> 
> Modified: head/sys/x86/x86/ucode.c
> ==============================================================================
> --- head/sys/x86/x86/ucode.c	Tue Aug 14 14:01:12 2018	(r337753)
> +++ head/sys/x86/x86/ucode.c	Tue Aug 14 14:02:53 2018	(r337754)
> @@ -312,8 +312,7 @@ ucode_load_bsp(uintptr_t free)
>  	uint8_t *addr, *fileaddr, *match;
>  	char *type;
>  	caddr_t file;
> -	size_t len, ucode_len;
> -	int i;
> +	size_t i, len, ucode_len;
>  
>  	KASSERT(free % PAGE_SIZE == 0, ("unaligned boundary %p", (void *)free));
>  
> @@ -345,7 +344,8 @@ ucode_load_bsp(uintptr_t free)
>  		match = loader->match(fileaddr, &len);
>  		if (match != NULL) {
>  			addr = map_ucode(free, len);
> -			memcpy(addr, match, len);
			/*
			 * NB: memcpy may be an uninitialized ifunc,
			 * so can not be used here.
			 */
> +			for (i = 0; i < len; i++)
> +				addr[i] = match[i];
>  			match = addr;
>  
>  			if (loader->load(match, false) == 0) {
> 
> 

-- 
Rod Grimes                                                 rgrimes at freebsd.org