On 05/25/2015 04:43 PM, Alexander Popov wrote: > On 25.05.2015 11:12, Andrey Ryabinin wrote: >> On 05/22/2015 07:03 PM, Alexander Popov wrote: >>> Physical addresses in KASan shadow region page tables need fixup: >>> kernel halts without it if phys_base is not zero. >>> >> >> Indeed. >> Since we have to patch page tables anyway, compile-time created kasan >> page tables become pointless. >> So, I'd suggest to create them in runtime. This could be done in plain C >> in kasan_map_early_shadow(). >> > > Thanks for your reply, Andrey. > > Creating kasan_zero_pud, kasan_zero_pmd and kasan_zero_pte in > kasan_map_early_shadow() doesn't look handy for me because this function > is called twice in x86_64_start_kernel(). > > What do you think about leaving the initialization of KASan shadow region > page tables in arch/x86/kernel/head_64.S and calling something like > kasan_fixup_early_shadow() before calling kasan_map_early_shadow() > for the first time? >
Why do we have initialize + fixup later if we could simply initialize page tables properly? Just move everything into kasan_init_64.c kasan_zero_p* could be a normal C arrays (with __page_aligned_bss attribute). Initialize these page tables in something like kasan_early_init() before kasan_map_early_shadow() call. > Best regards, > Alexander > > -- 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/
