Commit a4e74fa5 authored by Marco Elver's avatar Marco Elver Committed by Paul E. McKenney
Browse files

kcsan: Simplify constant string handling 



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: default avatarMarco Elver <elver@google.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent 69b2c81b

kernel/kcsan/debugfs.c

+4 −4
Original line number Diff line number Diff line
@@ -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")) {

kernel/kcsan/report.c

+2 −2
Original line number Diff line number Diff line
@@ -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. */

		}

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