On 15/07/17 21:20, René Scharfe wrote: > Simplify the code by using the helper macros COPY_ARRAY and MOVE_ARRAY, > which also makes them more robust in the case we copy or move no lines, > as they allow using NULL points in that case, while memcpy(3) and > memmove(3) don't. > > Found with Clang's UBSan. > > Signed-off-by: Rene Scharfe <l.s.r@xxxxxx> > --- > I don't know why the rules in contrib/coccinelle/array.cocci didn't > match. :-? > > apply.c | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) > > diff --git a/apply.c b/apply.c > index f2d599141d..40707ca50c 100644 > --- a/apply.c > +++ b/apply.c > @@ -2809,13 +2809,10 @@ static void update_image(struct apply_state *state, > img->line_allocated = img->line; > } > if (preimage_limit != postimage->nr) > - memmove(img->line + applied_pos + postimage->nr, > - img->line + applied_pos + preimage_limit, > - (img->nr - (applied_pos + preimage_limit)) * > - sizeof(*img->line)); > - memcpy(img->line + applied_pos, > - postimage->line, > - postimage->nr * sizeof(*img->line)); > + MOVE_ARRAY(img->line + applied_pos + postimage->nr, > + img->line + applied_pos + preimage_limit, > + img->nr - (applied_pos + preimage_limit)); > + COPY_ARRAY(img->line + applied_pos, postimage->line, postimage->nr); My patch looks like: - memcpy(img->line + applied_pos, - postimage->line, - postimage->nr * sizeof(*img->line)); + if (postimage->line && postimage->nr) + memcpy(img->line + applied_pos, + postimage->line, + postimage->nr * sizeof(*img->line)); ... which I think I prefer (slightly). ATB, Ramsay Jones > if (!state->allow_overlap) > for (i = 0; i < postimage->nr; i++) > img->line[applied_pos + i].flag |= LINE_PATCHED; >
