On Fri, 22 Nov 2019 at 12:28, <glider@xxxxxxxxxx> wrote: > > Disable the efficient 8-byte reading under KMSAN to avoid false positives. > > Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> > To: Alexander Potapenko <glider@xxxxxxxxxx> > Cc: Vegard Nossum <vegard.nossum@xxxxxxxxxx> > Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx> > Cc: linux-mm@xxxxxxxxx > > --- > > Change-Id: I25d1acf5c3df6eff85894cd94f5ddbe93308271c > --- > lib/string.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/lib/string.c b/lib/string.c > index 08ec58cc673b..15efdc51bda6 100644 > --- a/lib/string.c > +++ b/lib/string.c > @@ -186,7 +186,10 @@ ssize_t strscpy(char *dest, const char *src, size_t count) > if (count == 0 || WARN_ON_ONCE(count > INT_MAX)) > return -E2BIG; > > -#ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS > +/** Why a doc comment? > + * Disable the efficient 8-byte reading under KMSAN to avoid false positives. > + */ AFAIK the CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS case is about unaligned accesses crossing page boundaries. In the #else case it's still going to do word-at-a-time if both src and dest are aligned, so the comment above is somewhat inaccurate. > +#if defined(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) && !defined(CONFIG_KMSAN) > /* > * If src is unaligned, don't cross a page boundary, > * since we don't know if the next page is mapped. > -- > 2.24.0.432.g9d3f5f5b63-goog >
