We were wasting a byte due to an off-by-one bug. s[c]nprintf() doesn't write more than $2 bytes including the null byte, so trying to pass 'size-1' there is wasting one byte. Now that we use sprintf_end(), the situation isn't different: sprintf_end() will stop writing *before* 'end' --that is, at most the terminating null byte will be written at 'end-1'--.
Acked-by: Marco Elver <[email protected]> Cc: Kees Cook <[email protected]> Cc: Christopher Bazley <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Jann Horn <[email protected]> Cc: Andrew Morton <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Rasmus Villemoes <[email protected]> Cc: Marco Elver <[email protected]> Cc: Michal Hocko <[email protected]> Cc: Al Viro <[email protected]> Signed-off-by: Alejandro Colomar <[email protected]> --- mm/kfence/kfence_test.c | 4 ++-- mm/kmsan/kmsan_test.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c index bae382eca4ab..c635aa9d478b 100644 --- a/mm/kfence/kfence_test.c +++ b/mm/kfence/kfence_test.c @@ -110,7 +110,7 @@ static bool report_matches(const struct expect_report *r) /* Title */ cur = expect[0]; - end = &expect[0][sizeof(expect[0]) - 1]; + end = ENDOF(expect[0]); switch (r->type) { case KFENCE_ERROR_OOB: cur = sprintf_end(cur, end, "BUG: KFENCE: out-of-bounds %s", @@ -140,7 +140,7 @@ static bool report_matches(const struct expect_report *r) /* Access information */ cur = expect[1]; - end = &expect[1][sizeof(expect[1]) - 1]; + end = ENDOF(expect[1]); switch (r->type) { case KFENCE_ERROR_OOB: diff --git a/mm/kmsan/kmsan_test.c b/mm/kmsan/kmsan_test.c index e48ca1972ff3..9bda55992e3d 100644 --- a/mm/kmsan/kmsan_test.c +++ b/mm/kmsan/kmsan_test.c @@ -105,7 +105,7 @@ static bool report_matches(const struct expect_report *r) /* Title */ cur = expected_header; - end = &expected_header[sizeof(expected_header) - 1]; + end = ENDOF(expected_header); cur = sprintf_end(cur, end, "BUG: KMSAN: %s", r->error_type); -- 2.50.0
