Commit 4700ccdf authored by Marco Elver's avatar Marco Elver Committed by Paul E. McKenney
Browse files

kcsan: Remove debugfs test command 



Remove the debugfs test command, as it is no longer needed now that we
have the KUnit+Torture based kcsan-test module. This is to avoid
confusion around how KCSAN should be tested, as only the kcsan-test
module is maintained.

Signed-off-by: default avatarMarco Elver <elver@google.com>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent a4e74fa5

kernel/kcsan/debugfs.c

+0 −66
Original line number Diff line number Diff line
@@ -98,66 +98,6 @@ static noinline void microbenchmark(unsigned long iters) 
	current->kcsan_ctx = ctx_save;

}



/*

 * Simple test to create conflicting accesses. Write 'test=<iters>' to KCSAN's

 * debugfs file from multiple tasks to generate real conflicts and show reports.

 */

static long test_dummy;

static long test_flags;

static long test_scoped;

static noinline void test_thread(unsigned long iters)

{

	const long CHANGE_BITS = 0xff00ff00ff00ff00L;

	const struct kcsan_ctx ctx_save = current->kcsan_ctx;

	cycles_t cycles;



	/* We may have been called from an atomic region; reset context. */

	memset(&current->kcsan_ctx, 0, sizeof(current->kcsan_ctx));



	pr_info("KCSAN: %s begin | iters: %lu\n", __func__, iters);

	pr_info("test_dummy@%px, test_flags@%px, test_scoped@%px,\n",

		&test_dummy, &test_flags, &test_scoped);



	cycles = get_cycles();

	while (iters--) {

		/* These all should generate reports. */

		__kcsan_check_read(&test_dummy, sizeof(test_dummy));

		ASSERT_EXCLUSIVE_WRITER(test_dummy);

		ASSERT_EXCLUSIVE_ACCESS(test_dummy);



		ASSERT_EXCLUSIVE_BITS(test_flags, ~CHANGE_BITS); /* no report */

		__kcsan_check_read(&test_flags, sizeof(test_flags)); /* no report */



		ASSERT_EXCLUSIVE_BITS(test_flags, CHANGE_BITS); /* report */

		__kcsan_check_read(&test_flags, sizeof(test_flags)); /* no report */



		/* not actually instrumented */

		WRITE_ONCE(test_dummy, iters);  /* to observe value-change */

		__kcsan_check_write(&test_dummy, sizeof(test_dummy));



		test_flags ^= CHANGE_BITS; /* generate value-change */

		__kcsan_check_write(&test_flags, sizeof(test_flags));



		BUG_ON(current->kcsan_ctx.scoped_accesses.prev);

		{

			/* Should generate reports anywhere in this block. */

			ASSERT_EXCLUSIVE_WRITER_SCOPED(test_scoped);

			ASSERT_EXCLUSIVE_ACCESS_SCOPED(test_scoped);

			BUG_ON(!current->kcsan_ctx.scoped_accesses.prev);

			/* Unrelated accesses. */

			__kcsan_check_access(&cycles, sizeof(cycles), 0);

			__kcsan_check_access(&cycles, sizeof(cycles), KCSAN_ACCESS_ATOMIC);

		}

		BUG_ON(current->kcsan_ctx.scoped_accesses.prev);

	}

	cycles = get_cycles() - cycles;



	pr_info("KCSAN: %s end   | cycles: %llu\n", __func__, cycles);



	/* restore context */

	current->kcsan_ctx = ctx_save;

}



static int cmp_filterlist_addrs(const void *rhs, const void *lhs)

{

	const unsigned long a = *(const unsigned long *)rhs;
@@ -306,12 +246,6 @@ debugfs_write(struct file *file, const char __user *buf, size_t count, loff_t *o 
		if (kstrtoul(&arg[strlen("microbench=")], 0, &iters))

			return -EINVAL;

		microbenchmark(iters);

	} else if (str_has_prefix(arg, "test=")) {

		unsigned long iters;



		if (kstrtoul(&arg[strlen("test=")], 0, &iters))

			return -EINVAL;

		test_thread(iters);

	} else if (!strcmp(arg, "whitelist")) {

		set_report_filterlist_whitelist(true);

	} else if (!strcmp(arg, "blacklist")) {

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