2015-10-09 12:48 GMT+03:00 Mark Rutland <mark.rutland@xxxxxxx>: > On Fri, Oct 09, 2015 at 12:32:18PM +0300, Andrey Ryabinin wrote: > [...] > >> I thought the EFI stub isolation patches create a copy of mem*() functions in the stub, >> but they are just create aliases with __efistub_ prefix. >> >> We only need to create some more aliases for KASAN. >> The following patch on top of the EFI stub isolation series works for me. >> >> >> Signed-off-by: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx> >> --- >> arch/arm64/kernel/image.h | 6 ++++++ >> 1 file changed, 6 insertions(+) >> >> diff --git a/arch/arm64/kernel/image.h b/arch/arm64/kernel/image.h >> index e083af0..6eb8fee 100644 >> --- a/arch/arm64/kernel/image.h >> +++ b/arch/arm64/kernel/image.h >> @@ -80,6 +80,12 @@ __efistub_strcmp = __pi_strcmp; >> __efistub_strncmp = __pi_strncmp; >> __efistub___flush_dcache_area = __pi___flush_dcache_area; >> >> +#ifdef CONFIG_KASAN >> +__efistub___memcpy = __pi_memcpy; >> +__efistub___memmove = __pi_memmove; >> +__efistub___memset = __pi_memset; >> +#endif > > Ard's v4 stub isolation series has these aliases [1], as the stub > requires these aliases regardless of KASAN in order to link. Stub isolation series has __efistub_memcpy, not __efistub___memcpy (two additional '_'). The thing is, KASAN provides own implementation of memcpy() which checks memory before access. The original 'memcpy()' becomes __memcpy(), so we could still use it. In code that not instrumented by KASAN (like the EFI stub) we replace KASAN's memcpy() with the original __mempcy(): #define memcpy() __memcpy() So with CONFIG_KASAN=y the EFI stub uses __memcpy, thus we need to create the __efistub___memcpy alias. > > Thanks, > Mark. > > [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2015-October/375708.html -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
