The kasan_check_read() is marked 'inline', which usually includes
the 'always_inline' attribute. In some configuration, gcc decides that
it cannot inline this, causing a build failure:
In file included from include/linux/compiler.h:257,
from arch/x86/include/asm/current.h:5,
from include/linux/sched.h:12,
from include/linux/ratelimit.h:6,
from fs/dcache.c:18:
include/linux/compiler.h: In function 'read_word_at_a_time':
include/linux/kasan-checks.h:31:20: error: inlining failed in call to always_inline 'kasan_check_read': function attribute mismatch
static inline bool kasan_check_read(const volatile void *p, unsigned int size)
^~~~~~~~~~~~~~~~
In file included from arch/x86/include/asm/current.h:5,
from include/linux/sched.h:12,
from include/linux/ratelimit.h:6,
from fs/dcache.c:18:
include/linux/compiler.h:280:2: note: called from here
kasan_check_read(addr, 1);
^~~~~~~~~~~~~~~~~~~~~~~~~
While I have no idea why it does this, but changing the call to the
internal __kasan_check_read() fixes the issue.
Fixes: dc55b51f312c ("mm/kasan: introduce __kasan_check_{read,write}")
Signed-off-by: Arnd Bergmann <[email protected]>
---
include/linux/compiler.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index f0fd5636fddb..22909500ba1d 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -277,7 +277,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
static __no_kasan_or_inline
unsigned long read_word_at_a_time(const void *addr)
{
- kasan_check_read(addr, 1);
+ __kasan_check_read(addr, 1);
return *(unsigned long *)addr;
}
--
2.20.0
On Tue, 9 Jul 2019 at 20:36, Arnd Bergmann <[email protected]> wrote:
>
> The kasan_check_read() is marked 'inline', which usually includes
> the 'always_inline' attribute. In some configuration, gcc decides that
> it cannot inline this, causing a build failure:
>
> In file included from include/linux/compiler.h:257,
> from arch/x86/include/asm/current.h:5,
> from include/linux/sched.h:12,
> from include/linux/ratelimit.h:6,
> from fs/dcache.c:18:
> include/linux/compiler.h: In function 'read_word_at_a_time':
> include/linux/kasan-checks.h:31:20: error: inlining failed in call to always_inline 'kasan_check_read': function attribute mismatch
> static inline bool kasan_check_read(const volatile void *p, unsigned int size)
> ^~~~~~~~~~~~~~~~
> In file included from arch/x86/include/asm/current.h:5,
> from include/linux/sched.h:12,
> from include/linux/ratelimit.h:6,
> from fs/dcache.c:18:
> include/linux/compiler.h:280:2: note: called from here
> kasan_check_read(addr, 1);
> ^~~~~~~~~~~~~~~~~~~~~~~~~
>
> While I have no idea why it does this, but changing the call to the
> internal __kasan_check_read() fixes the issue.
Thanks, this was fixed more generally in v5:
http://lkml.kernel.org/r/[email protected]
>
> Fixes: dc55b51f312c ("mm/kasan: introduce __kasan_check_{read,write}")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> include/linux/compiler.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/compiler.h b/include/linux/compiler.h
> index f0fd5636fddb..22909500ba1d 100644
> --- a/include/linux/compiler.h
> +++ b/include/linux/compiler.h
> @@ -277,7 +277,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
> static __no_kasan_or_inline
> unsigned long read_word_at_a_time(const void *addr)
> {
> - kasan_check_read(addr, 1);
> + __kasan_check_read(addr, 1);
> return *(unsigned long *)addr;
> }
>
> --
> 2.20.0
>
On Tue, Jul 9, 2019 at 11:36 AM Arnd Bergmann <[email protected]> wrote:
>
> The kasan_check_read() is marked 'inline', which usually includes
> the 'always_inline' attribute. In some configuration, gcc decides that
> it cannot inline this, causing a build failure:
>
> In file included from include/linux/compiler.h:257,
> from arch/x86/include/asm/current.h:5,
> from include/linux/sched.h:12,
> from include/linux/ratelimit.h:6,
> from fs/dcache.c:18:
> include/linux/compiler.h: In function 'read_word_at_a_time':
> include/linux/kasan-checks.h:31:20: error: inlining failed in call to always_inline 'kasan_check_read': function attribute mismatch
Sounds like the error `function attribute mismatch` is saying:
kasan_check_read has one set of function attributes, but the call site
read_word_at_a_time has different function attributes, so I wont
inline kasan_check_read into read_word_at_a_time.
__no_kasan_or_inline changes based on CONFIG_KASAN; was this from a
kasan build or not?
> static inline bool kasan_check_read(const volatile void *p, unsigned int size)
> ^~~~~~~~~~~~~~~~
> In file included from arch/x86/include/asm/current.h:5,
> from include/linux/sched.h:12,
> from include/linux/ratelimit.h:6,
> from fs/dcache.c:18:
> include/linux/compiler.h:280:2: note: called from here
> kasan_check_read(addr, 1);
> ^~~~~~~~~~~~~~~~~~~~~~~~~
>
> While I have no idea why it does this, but changing the call to the
> internal __kasan_check_read() fixes the issue.
>
> Fixes: dc55b51f312c ("mm/kasan: introduce __kasan_check_{read,write}")
> Signed-off-by: Arnd Bergmann <[email protected]>
> ---
> include/linux/compiler.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/include/linux/compiler.h b/include/linux/compiler.h
> index f0fd5636fddb..22909500ba1d 100644
> --- a/include/linux/compiler.h
> +++ b/include/linux/compiler.h
> @@ -277,7 +277,7 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
> static __no_kasan_or_inline
> unsigned long read_word_at_a_time(const void *addr)
> {
> - kasan_check_read(addr, 1);
> + __kasan_check_read(addr, 1);
> return *(unsigned long *)addr;
> }
>
> --
> 2.20.0
>
--
Thanks,
~Nick Desaulniers
On Tue, Jul 9, 2019 at 8:46 PM Marco Elver <[email protected]> wrote:
>
> On Tue, 9 Jul 2019 at 20:36, Arnd Bergmann <[email protected]> wrote:
> >
> > The kasan_check_read() is marked 'inline', which usually includes
> > the 'always_inline' attribute. In some configuration, gcc decides that
> > it cannot inline this, causing a build failure:
> >
> > In file included from include/linux/compiler.h:257,
> > from arch/x86/include/asm/current.h:5,
> > from include/linux/sched.h:12,
> > from include/linux/ratelimit.h:6,
> > from fs/dcache.c:18:
> > include/linux/compiler.h: In function 'read_word_at_a_time':
> > include/linux/kasan-checks.h:31:20: error: inlining failed in call to always_inline 'kasan_check_read': function attribute mismatch
> > static inline bool kasan_check_read(const volatile void *p, unsigned int size)
> > ^~~~~~~~~~~~~~~~
> > In file included from arch/x86/include/asm/current.h:5,
> > from include/linux/sched.h:12,
> > from include/linux/ratelimit.h:6,
> > from fs/dcache.c:18:
> > include/linux/compiler.h:280:2: note: called from here
> > kasan_check_read(addr, 1);
> > ^~~~~~~~~~~~~~~~~~~~~~~~~
> >
> > While I have no idea why it does this, but changing the call to the
> > internal __kasan_check_read() fixes the issue.
>
> Thanks, this was fixed more generally in v5:
> http://lkml.kernel.org/r/[email protected]
Ok, that looks like a better solution indeed. I tried something
similar at first but got it wrong.
Arnd