[PATCH 2/5 v16] ARM: Replace string mem* functions for KASan

[Nathan Chancellor]

On Fri, Nov 06, 2020 at 09:28:09AM +0100, Ard Biesheuvel wrote:
> On Fri, 6 Nov 2020 at 09:26, Linus Walleij <linus.walleij at linaro.org> wrote:
> >
> > On Fri, Nov 6, 2020 at 8:49 AM Naresh Kamboju <naresh.kamboju at linaro.org> wrote:
> >
> > > arm KASAN build failure noticed on linux next 20201106 tag.
> > > gcc: 9.x
> > >
> > > Build error:
> > > ---------------
> > > arch/arm/boot/compressed/string.c:24:1: error: attribute 'alias'
> > > argument not a string
> > >    24 | void *__memcpy(void *__dest, __const void *__src, size_t __n)
> > > __alias(memcpy);
> > >       | ^~~~
> > > arch/arm/boot/compressed/string.c:25:1: error: attribute 'alias'
> > > argument not a string
> > >    25 | void *__memmove(void *__dest, __const void *__src, size_t
> > > count) __alias(memmove);
> > >       | ^~~~
> > > arch/arm/boot/compressed/string.c:26:1: error: attribute 'alias'
> > > argument not a string
> > >    26 | void *__memset(void *s, int c, size_t count) __alias(memset);
> > >       | ^~~~
> > >
> > > Reported-by: Naresh Kamboju <naresh.kamboju at linaro.org>
> > >
> > > Build details link,
> > > https://builds.tuxbuild.com/1juBs4tXRA6Cwhd1Qnhh4vzCtDx/
> >
> > This looks like a randconfig build.
> >
> > Please drill down and try to report which combination of config
> > options that give rise to this problem so we have a chance of
> > amending it.
> >
> 
> AFAIK there is an incompatible change in -next to change the
> definition of the __alias() macro

Indeed. The following diff needs to be applied as a fixup to
treewide-remove-stringification-from-__alias-macro-definition.patch in
mmotm.

Cheers,
Nathan

diff --git a/arch/arm/boot/compressed/string.c b/arch/arm/boot/compressed/string.c
index 8c0fa276d994..cc6198f8a348 100644
--- a/arch/arm/boot/compressed/string.c
+++ b/arch/arm/boot/compressed/string.c
@@ -21,9 +21,9 @@
 #undef memcpy
 #undef memmove
 #undef memset
-void *__memcpy(void *__dest, __const void *__src, size_t __n) __alias(memcpy);
-void *__memmove(void *__dest, __const void *__src, size_t count) __alias(memmove);
-void *__memset(void *s, int c, size_t count) __alias(memset);
+void *__memcpy(void *__dest, __const void *__src, size_t __n) __alias("memcpy");
+void *__memmove(void *__dest, __const void *__src, size_t count) __alias("memmove");
+void *__memset(void *s, int c, size_t count) __alias("memset");
 #endif
 
 void *memcpy(void *__dest, __const void *__src, size_t __n)