On 01/30/2015 02:12 AM, Andrew Morton wrote: > On Thu, 29 Jan 2015 18:11:57 +0300 Andrey Ryabinin <a.ryabi...@samsung.com> > wrote: > >> For instrumenting global variables KASan will shadow memory >> backing memory for modules. So on module loading we will need >> to allocate shadow memory and map it at exact virtual address. > > I don't understand. What does "map it at exact virtual address" mean? >
I mean that if module_alloc() returned address x, than shadow memory should be mapped exactly at address kasan_mem_to_shadow(x). >> __vmalloc_node_range() seems like the best fit for that purpose, >> except it puts a guard hole after allocated area. > > Why is the guard hole a problem? > Because of guard hole in shadow some future allocations of shadow memory will fail. Requested address ( kasan_mem_to_shadow(x) ) will be already occupied by guard hole of previous allocation. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
