On Thu, Aug 31, 2023 at 3:16 PM Helge Deller <del...@gmx.de> wrote: > > * Nick Desaulniers <ndesaulni...@google.com>: > > On Thu, Aug 31, 2023 at 2:23 PM Helge Deller <del...@gmx.de> wrote: > > > > > > * Helge Deller <del...@gmx.de>: > > > > On 8/29/23 18:45, Nick Desaulniers wrote: > > > > > A recent change in clang made it better about spotting snprintf that > > > > > will result in truncation. Nathan reported the following instances: > > > > > > > > > > drivers/video/fbdev/neofb.c:1959:3: warning: 'snprintf' will always be > > > > > truncated; specified size is 16, but format string expands to at least > > > > > 17 [-Wfortify-source] > > > > > > FYI, I've added the patch below to the fbdev for-next git tree. > > > [...] > > > > This indeed makes the warning go away, but that's more so due to the > > use of strscpy now rather than snprintf. That alone is a good change > > but we still have definite truncation. See below: > > [...] > > Nick, thanks for your review and findings! > Now every string should be max. 15 chars (which fits with the trailing > NUL into the char[16] array). > > Helge > > > Subject: [PATCH] fbdev: neofb: Shorten Neomagic product name in info struct > > Avoid those compiler warnings: > neofb.c:1959:3: warning: 'snprintf' will always be truncated; > specified size is 16, but format string expands to at least 17 > [-Wfortify-source] > > Signed-off-by: Helge Deller <del...@gmx.de> > Reported-by: Nathan Chancellor <nat...@kernel.org> > Reported-by: Nick Desaulniers <ndesaulni...@google.com> > Link: > https://lore.kernel.org/all/cakwvodn0xovwjq6ufm_rojtkb0f1i1hw-j_xygfkdnfdhwa...@mail.gmail.com/ > Link: https://github.com/ClangBuiltLinux/linux/issues/1923
ah yeah LGTM Reviewed-by: Nick Desaulniers <ndesaulni...@google.com> > > diff --git a/drivers/video/fbdev/neofb.c b/drivers/video/fbdev/neofb.c > index d2f622b4c372..b58b11015c0c 100644 > --- a/drivers/video/fbdev/neofb.c > +++ b/drivers/video/fbdev/neofb.c > @@ -1948,49 +1948,40 @@ static struct fb_info *neo_alloc_fb_info(struct > pci_dev *dev, > > switch (info->fix.accel) { > case FB_ACCEL_NEOMAGIC_NM2070: > - snprintf(info->fix.id, sizeof(info->fix.id), > - "MagicGraph 128"); > + strscpy(info->fix.id, "MagicGraph128", sizeof(info->fix.id)); > break; > case FB_ACCEL_NEOMAGIC_NM2090: > - snprintf(info->fix.id, sizeof(info->fix.id), > - "MagicGraph 128V"); > + strscpy(info->fix.id, "MagicGraph128V", sizeof(info->fix.id)); > break; > case FB_ACCEL_NEOMAGIC_NM2093: > - snprintf(info->fix.id, sizeof(info->fix.id), > - "MagicGraph 128ZV"); > + strscpy(info->fix.id, "MagicGraph128ZV", > sizeof(info->fix.id)); > break; > case FB_ACCEL_NEOMAGIC_NM2097: > - snprintf(info->fix.id, sizeof(info->fix.id), > - "MagicGraph 128ZV+"); > + strscpy(info->fix.id, "Mag.Graph128ZV+", > sizeof(info->fix.id)); > break; > case FB_ACCEL_NEOMAGIC_NM2160: > - snprintf(info->fix.id, sizeof(info->fix.id), > - "MagicGraph 128XD"); > + strscpy(info->fix.id, "MagicGraph128XD", > sizeof(info->fix.id)); > break; > case FB_ACCEL_NEOMAGIC_NM2200: > - snprintf(info->fix.id, sizeof(info->fix.id), > - "MagicGraph 256AV"); > + strscpy(info->fix.id, "MagicGraph256AV", > sizeof(info->fix.id)); > info->flags |= FBINFO_HWACCEL_IMAGEBLIT | > FBINFO_HWACCEL_COPYAREA | > FBINFO_HWACCEL_FILLRECT; > break; > case FB_ACCEL_NEOMAGIC_NM2230: > - snprintf(info->fix.id, sizeof(info->fix.id), > - "MagicGraph 256AV+"); > + strscpy(info->fix.id, "Mag.Graph256AV+", > sizeof(info->fix.id)); > info->flags |= FBINFO_HWACCEL_IMAGEBLIT | > FBINFO_HWACCEL_COPYAREA | > FBINFO_HWACCEL_FILLRECT; > break; > case FB_ACCEL_NEOMAGIC_NM2360: > - snprintf(info->fix.id, sizeof(info->fix.id), > - "MagicGraph 256ZX"); > + strscpy(info->fix.id, "MagicGraph256ZX", > sizeof(info->fix.id)); > info->flags |= FBINFO_HWACCEL_IMAGEBLIT | > FBINFO_HWACCEL_COPYAREA | > FBINFO_HWACCEL_FILLRECT; > break; > case FB_ACCEL_NEOMAGIC_NM2380: > - snprintf(info->fix.id, sizeof(info->fix.id), > - "MagicGraph 256XL+"); > + strscpy(info->fix.id, "Mag.Graph256XL+", > sizeof(info->fix.id)); > info->flags |= FBINFO_HWACCEL_IMAGEBLIT | > FBINFO_HWACCEL_COPYAREA | > FBINFO_HWACCEL_FILLRECT; > -- Thanks, ~Nick Desaulniers