From: Marco Elver <elver@google.com>
To: elver@google.com, paulmck@kernel.org
Cc: dvyukov@google.com, glider@google.com, andreyknvl@google.com,
kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org
Subject: [PATCH 2/5] kcsan: Simplify constant string handling
Date: Fri, 31 Jul 2020 10:17:20 +0200 [thread overview]
Message-ID: <20200731081723.2181297-3-elver@google.com> (raw)
In-Reply-To: <20200731081723.2181297-1-elver@google.com>
Simplify checking prefixes and length calculation of constant strings.
For the former, the kernel provides str_has_prefix(), and the latter we
should just use strlen("..") because GCC and Clang have optimizations
that optimize these into constants.
No functional change intended.
Signed-off-by: Marco Elver <elver@google.com>
---
kernel/kcsan/debugfs.c | 8 ++++----
kernel/kcsan/report.c | 4 ++--
2 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/kernel/kcsan/debugfs.c b/kernel/kcsan/debugfs.c
index 3a9566addeff..116bdd8f050c 100644
--- a/kernel/kcsan/debugfs.c
+++ b/kernel/kcsan/debugfs.c
@@ -300,16 +300,16 @@ debugfs_write(struct file *file, const char __user *buf, size_t count, loff_t *o
WRITE_ONCE(kcsan_enabled, true);
} else if (!strcmp(arg, "off")) {
WRITE_ONCE(kcsan_enabled, false);
- } else if (!strncmp(arg, "microbench=", sizeof("microbench=") - 1)) {
+ } else if (str_has_prefix(arg, "microbench=")) {
unsigned long iters;
- if (kstrtoul(&arg[sizeof("microbench=") - 1], 0, &iters))
+ if (kstrtoul(&arg[strlen("microbench=")], 0, &iters))
return -EINVAL;
microbenchmark(iters);
- } else if (!strncmp(arg, "test=", sizeof("test=") - 1)) {
+ } else if (str_has_prefix(arg, "test=")) {
unsigned long iters;
- if (kstrtoul(&arg[sizeof("test=") - 1], 0, &iters))
+ if (kstrtoul(&arg[strlen("test=")], 0, &iters))
return -EINVAL;
test_thread(iters);
} else if (!strcmp(arg, "whitelist")) {
diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
index d05052c23261..15add93ff12e 100644
--- a/kernel/kcsan/report.c
+++ b/kernel/kcsan/report.c
@@ -279,8 +279,8 @@ static int get_stack_skipnr(const unsigned long stack_entries[], int num_entries
cur = strnstr(buf, "kcsan_", len);
if (cur) {
- cur += sizeof("kcsan_") - 1;
- if (strncmp(cur, "test", sizeof("test") - 1))
+ cur += strlen("kcsan_");
+ if (!str_has_prefix(cur, "test"))
continue; /* KCSAN runtime function. */
/* KCSAN related test. */
}
--
2.28.0.163.g6104cc2f0b6-goog
next prev parent reply other threads:[~2020-07-31 8:17 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-31 8:17 [PATCH 0/5] kcsan: Cleanups, readability, and cosmetic improvements Marco Elver
2020-07-31 8:17 ` [PATCH 1/5] kcsan: Simplify debugfs counter to name mapping Marco Elver
2020-07-31 8:17 ` Marco Elver [this message]
2020-07-31 8:17 ` [PATCH 3/5] kcsan: Remove debugfs test command Marco Elver
2020-07-31 8:17 ` [PATCH 4/5] kcsan: Show message if enabled early Marco Elver
2020-07-31 8:17 ` [PATCH 5/5] kcsan: Use pr_fmt for consistency Marco Elver
2020-08-03 16:52 ` [PATCH 0/5] kcsan: Cleanups, readability, and cosmetic improvements Paul E. McKenney
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