From: paulmck@kernel.org
To: linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
kernel-team@fb.com, mingo@kernel.org
Cc: elver@google.com, andreyknvl@google.com, glider@google.com,
dvyukov@google.com, cai@lca.pw, boqun.feng@gmail.com,
"Paul E . McKenney" <paulmck@kernel.org>
Subject: [PATCH kcsan 13/19] kcsan: Simplify constant string handling
Date: Mon, 31 Aug 2020 11:17:59 -0700 [thread overview]
Message-ID: <20200831181805.1833-13-paulmck@kernel.org> (raw)
In-Reply-To: <20200831181715.GA1530@paulmck-ThinkPad-P72>
From: Marco Elver <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>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
---
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 3a9566a..116bdd8 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 3e83a69..bf1d594 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. */
}
--
2.9.5
next prev parent reply other threads:[~2020-08-31 18:19 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-31 18:17 [PATCH kcsan 0/19] KCSAN updates for v5.10 Paul E. McKenney
2020-08-31 18:17 ` [PATCH kcsan 01/19] kcsan: Add support for atomic builtins paulmck
2020-08-31 18:17 ` [PATCH kcsan 02/19] objtool: Add atomic builtin TSAN instrumentation to uaccess whitelist paulmck
2020-08-31 18:17 ` [PATCH kcsan 03/19] kcsan: Add atomic builtin test case paulmck
2020-08-31 18:17 ` [PATCH kcsan 04/19] kcsan: Support compounded read-write instrumentation paulmck
2020-08-31 18:17 ` [PATCH kcsan 05/19] objtool, kcsan: Add __tsan_read_write to uaccess whitelist paulmck
2020-08-31 18:17 ` [PATCH kcsan 06/19] kcsan: Skew delay to be longer for certain access types paulmck
2020-08-31 18:17 ` [PATCH kcsan 07/19] kcsan: Add missing CONFIG_KCSAN_IGNORE_ATOMICS checks paulmck
2020-08-31 18:17 ` [PATCH kcsan 08/19] kcsan: Test support for compound instrumentation paulmck
2020-08-31 18:17 ` [PATCH kcsan 09/19] instrumented.h: Introduce read-write instrumentation hooks paulmck
2020-08-31 18:17 ` [PATCH kcsan 10/19] asm-generic/bitops: Use instrument_read_write() where appropriate paulmck
2020-08-31 18:17 ` [PATCH kcsan 11/19] locking/atomics: Use read-write instrumentation for atomic RMWs paulmck
2020-08-31 18:17 ` [PATCH kcsan 12/19] kcsan: Simplify debugfs counter to name mapping paulmck
2020-08-31 18:17 ` paulmck [this message]
2020-08-31 18:18 ` [PATCH kcsan 14/19] kcsan: Remove debugfs test command paulmck
2020-08-31 18:18 ` [PATCH kcsan 15/19] kcsan: Show message if enabled early paulmck
2020-08-31 18:18 ` [PATCH kcsan 16/19] kcsan: Use pr_fmt for consistency paulmck
2020-08-31 18:18 ` [PATCH kcsan 17/19] kcsan: Optimize debugfs stats counters paulmck
2020-08-31 18:18 ` [PATCH kcsan 18/19] bitops, kcsan: Partially revert instrumentation for non-atomic bitops paulmck
2020-09-02 3:30 ` Boqun Feng
2020-09-02 6:13 ` Marco Elver
2020-09-04 1:24 ` Boqun Feng
2020-08-31 18:18 ` [PATCH kcsan 19/19] kcsan: Use tracing-safe version of prandom paulmck
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