strncmp(str, const, len) is error-prone because len is easy to have typo. The example is the hard-coded len has counting error or sizeof(const) forgets - 1. So we prefer using newly introduced str_has_prefix() to substitute such strncmp to make code better.
Signed-off-by: Chuhong Yuan <[email protected]> --- Changes in v4: - Eliminate assignments in if conditions. kernel/sched/debug.c | 6 ++++-- kernel/sched/isolation.c | 11 +++++++---- 2 files changed, 11 insertions(+), 6 deletions(-) diff --git a/kernel/sched/debug.c b/kernel/sched/debug.c index f7e4579e746c..a03900523e5d 100644 --- a/kernel/sched/debug.c +++ b/kernel/sched/debug.c @@ -102,10 +102,12 @@ static int sched_feat_set(char *cmp) { int i; int neg = 0; + size_t len; - if (strncmp(cmp, "NO_", 3) == 0) { + len = str_has_prefix(cmp, "NO_"); + if (len) { neg = 1; - cmp += 3; + cmp += len; } i = match_string(sched_feat_names, __SCHED_FEAT_NR, cmp); diff --git a/kernel/sched/isolation.c b/kernel/sched/isolation.c index ccb28085b114..ea2ead4b1906 100644 --- a/kernel/sched/isolation.c +++ b/kernel/sched/isolation.c @@ -141,16 +141,19 @@ __setup("nohz_full=", housekeeping_nohz_full_setup); static int __init housekeeping_isolcpus_setup(char *str) { unsigned int flags = 0; + size_t len; while (isalpha(*str)) { - if (!strncmp(str, "nohz,", 5)) { - str += 5; + len = str_has_prefix(str, "nohz,"); + if (len) { + str += len; flags |= HK_FLAG_TICK; continue; } - if (!strncmp(str, "domain,", 7)) { - str += 7; + len = str_has_prefix(str, "domain,"); + if (len) { + str += len; flags |= HK_FLAG_DOMAIN; continue; } -- 2.20.1
