Messages in this thread | | | Subject | Re: [PATCH] powerpc/32: disable KASAN with pages bigger than 16k | From | Christophe Leroy <> | Date | Sat, 30 May 2020 19:22:28 +0200 |
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Le 28/05/2020 à 12:17, Christophe Leroy a écrit : > Mapping of early shadow area is implemented by using a single static > page table having all entries pointing to the same early shadow page. > The shadow area must therefore occupy full PGD entries. > > The shadow area has a size of 128Mbytes starting at 0xf8000000. > With 4k pages, a PGD entry is 4Mbytes > With 16k pages, a PGD entry is 64Mbytes > With 64k pages, a PGD entry is 256Mbytes which is too big.
That's for 32k pages that a PGD is 256Mbytes.
With 64k pages, a PGD entry is 1Gbytes which is too big.
Michael, can you fix the commit log ?
Thanks Christophe
> > Until we rework the early shadow mapping, disable KASAN when the > page size is too big. > > Reported-by: kbuild test robot <lkp@intel.com> > Fixes: 2edb16efc899 ("powerpc/32: Add KASAN support") > Cc: stable@vger.kernel.org > Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> > --- > arch/powerpc/Kconfig | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 1dfa59126fcf..066b36bf9efa 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -169,8 +169,8 @@ config PPC > select HAVE_ARCH_AUDITSYSCALL > select HAVE_ARCH_HUGE_VMAP if PPC_BOOK3S_64 && PPC_RADIX_MMU > select HAVE_ARCH_JUMP_LABEL > - select HAVE_ARCH_KASAN if PPC32 > - select HAVE_ARCH_KASAN_VMALLOC if PPC32 > + select HAVE_ARCH_KASAN if PPC32 && PPC_PAGE_SHIFT <= 14 > + select HAVE_ARCH_KASAN_VMALLOC if PPC32 && PPC_PAGE_SHIFT <= 14 > select HAVE_ARCH_KGDB > select HAVE_ARCH_MMAP_RND_BITS > select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT >
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