[PATCH] PM / Hibernate: Don't let kasan instrument snapshot.c

[Rafael J. Wysocki]

On Thursday, June 02, 2016 01:20:32 PM James Morse wrote:
> Kasan causes the compiler to instrument C code and is used at runtime to
> detect accesses to memory that has been freed, or not yet allocated.
> 
> The code in snapshot.c saves and restores memory when hibernating. This will
> access whole pages in the slab cache that have both free and allocated
> areas, resulting in a large number of false positives from Kasan.
> 
> Disable instrumentation of this file.
> 
> Signed-off-by: James Morse <james.morse at arm.com>
> Acked-by: Catalin Marinas <catalin.marinas at arm.com>
> 
> ---
> With this, I can hibernate/resume a kernel built with kasan on arm64.
> 
>  kernel/power/Makefile | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/kernel/power/Makefile b/kernel/power/Makefile
> index cb880a14cc39..eb4f717705ba 100644
> --- a/kernel/power/Makefile
> +++ b/kernel/power/Makefile
> @@ -1,6 +1,8 @@
>  
>  ccflags-$(CONFIG_PM_DEBUG)	:= -DDEBUG
>  
> +KASAN_SANITIZE_snapshot.o	:= n
> +
>  obj-y				+= qos.o
>  obj-$(CONFIG_PM)		+= main.o
>  obj-$(CONFIG_VT_CONSOLE_SLEEP)	+= console.o
> 

Applied, thanks!

Does the arch code need to be annotated in a similar way too?