Re: [PATCH] arm64: lib: use C string functions with KASAN enabled.

Will Deacon
2018-09-07T14:55:53Z

On Thu, Sep 06, 2018 at 08:05:33PM +0300, Andrey Ryabinin wrote:
> ARM64 has asm implementations of memchr(), memcmp(), str[r]chr(),
> str[n]cmp(), str[n]len(). KASAN don't see memory accesses in asm
> code, thus it can potentially miss many bugs.
>
> Ifdef out __HAVE_ARCH_* defines of these functions when KASAN is
> enabled, so the generic implementations from lib/string.c will be used.
>
> Declare asm functions as weak instead of removing them because they
> still can be used by efistub.

I don't understand this bit: efistub uses the __pi_ prefixed versions of the
routines, so why do we need to declare them as weak?

Will