len is guaranteed to lie in [1, PAGE_SIZE]. If scnprintf is called with a buffer size of 1, it is guaranteed to return 0. So in the extremely unlikely case of having just one byte remaining in the page, let's just call scnprintf anyway. The only difference is that this will write a '\0' to that final byte in the page, but that's an improvement: We now guarantee that after the call, buf is a properly terminated C string of length exactly the return value.
Signed-off-by: Rasmus Villemoes <li...@rasmusvillemoes.dk> --- lib/bitmap.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/lib/bitmap.c b/lib/bitmap.c index 277c9a63a5ab..75175da01fd8 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -469,12 +469,9 @@ int bitmap_print_to_pagebuf(bool list, char *buf, const unsigned long *maskp, int nmaskbits) { ptrdiff_t len = PAGE_SIZE - ((unsigned long)buf & (PAGE_SIZE-1)); - int n = 0; - if (len > 1) - n = list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : - scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); - return n; + return list ? scnprintf(buf, len, "%*pbl\n", nmaskbits, maskp) : + scnprintf(buf, len, "%*pb\n", nmaskbits, maskp); } EXPORT_SYMBOL(bitmap_print_to_pagebuf); -- 2.16.4