kselftest/seccomp: Use kselftest output functions for benchmark

In preparation for trying to output the test results themselves in TAP
format rework all the prints in the benchmark to use the kselftest output
functions. The uses of system() all produce single line output so we can
avoid having to deal with fully managing the child process and continue to
use system() by simply printing an empty message before we invoke system().
We also leave one printf() used to complete a line of output in place.

Tested-by: Anders Roxell <anders.roxell@linaro.org>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Author: broonie

tools/testing/selftests/seccomp/seccomp_benchmark.c

@@ -38,10 +38,10 @@ unsigned long long timing(clockid_t clk_id, unsigned long long samples)
 	i *= 1000000000ULL;
 	i += finish.tv_nsec - start.tv_nsec;
 
-	printf("%lu.%09lu - %lu.%09lu = %llu (%.1fs)\n",
-		finish.tv_sec, finish.tv_nsec,
-		start.tv_sec, start.tv_nsec,
-		i, (double)i / 1000000000.0);
+	ksft_print_msg("%lu.%09lu - %lu.%09lu = %llu (%.1fs)\n",
+		       finish.tv_sec, finish.tv_nsec,
+		       start.tv_sec, start.tv_nsec,
+		       i, (double)i / 1000000000.0);
 
 	return i;
 }
@@ -53,7 +53,7 @@ unsigned long long calibrate(void)
 	pid_t pid, ret;
 	int seconds = 15;
 
-	printf("Calibrating sample size for %d seconds worth of syscalls ...\n", seconds);
+	ksft_print_msg("Calibrating sample size for %d seconds worth of syscalls ...\n", seconds);
 
 	samples = 0;
 	pid = getpid();
@@ -102,14 +102,14 @@ long compare(const char *name_one, const char *name_eval, const char *name_two,
 {
 	bool good;
 
-	printf("\t%s %s %s (%lld %s %lld): ", name_one, name_eval, name_two,
-	       (long long)one, name_eval, (long long)two);
+	ksft_print_msg("\t%s %s %s (%lld %s %lld): ", name_one, name_eval, name_two,
+		       (long long)one, name_eval, (long long)two);
 	if (one > INT_MAX) {
-		printf("Miscalculation! Measurement went negative: %lld\n", (long long)one);
+		ksft_print_msg("Miscalculation! Measurement went negative: %lld\n", (long long)one);
 		return 1;
 	}
 	if (two > INT_MAX) {
-		printf("Miscalculation! Measurement went negative: %lld\n", (long long)two);
+		ksft_print_msg("Miscalculation! Measurement went negative: %lld\n", (long long)two);
 		return 1;
 	}
 
@@ -145,24 +145,27 @@ int main(int argc, char *argv[])
 
 	setbuf(stdout, NULL);
 
-	printf("Running on:\n");
+	ksft_print_msg("Running on:\n");
+	ksft_print_msg("");
 	system("uname -a");
 
-	printf("Current BPF sysctl settings:\n");
+	ksft_print_msg("Current BPF sysctl settings:\n");
 	/* Avoid using "sysctl" which may not be installed. */
+	ksft_print_msg("");
 	system("grep -H . /proc/sys/net/core/bpf_jit_enable");
+	ksft_print_msg("");
 	system("grep -H . /proc/sys/net/core/bpf_jit_harden");
 
 	if (argc > 1)
 		samples = strtoull(argv[1], NULL, 0);
 	else
 		samples = calibrate();
 
-	printf("Benchmarking %llu syscalls...\n", samples);
+	ksft_print_msg("Benchmarking %llu syscalls...\n", samples);
 
 	/* Native call */
 	native = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples;
-	printf("getpid native: %llu ns\n", native);
+	ksft_print_msg("getpid native: %llu ns\n", native);
 
 	ret = prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
 	assert(ret == 0);
@@ -172,33 +175,33 @@ int main(int argc, char *argv[])
 	assert(ret == 0);
 
 	bitmap1 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples;
-	printf("getpid RET_ALLOW 1 filter (bitmap): %llu ns\n", bitmap1);
+	ksft_print_msg("getpid RET_ALLOW 1 filter (bitmap): %llu ns\n", bitmap1);
 
 	/* Second filter resulting in a bitmap */
 	ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &bitmap_prog);
 	assert(ret == 0);
 
 	bitmap2 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples;
-	printf("getpid RET_ALLOW 2 filters (bitmap): %llu ns\n", bitmap2);
+	ksft_print_msg("getpid RET_ALLOW 2 filters (bitmap): %llu ns\n", bitmap2);
 
 	/* Third filter, can no longer be converted to bitmap */
 	ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &prog);
 	assert(ret == 0);
 
 	filter1 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples;
-	printf("getpid RET_ALLOW 3 filters (full): %llu ns\n", filter1);
+	ksft_print_msg("getpid RET_ALLOW 3 filters (full): %llu ns\n", filter1);
 
 	/* Fourth filter, can not be converted to bitmap because of filter 3 */
 	ret = prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &bitmap_prog);
 	assert(ret == 0);
 
 	filter2 = timing(CLOCK_PROCESS_CPUTIME_ID, samples) / samples;
-	printf("getpid RET_ALLOW 4 filters (full): %llu ns\n", filter2);
+	ksft_print_msg("getpid RET_ALLOW 4 filters (full): %llu ns\n", filter2);
 
 	/* Estimations */
 #define ESTIMATE(fmt, var, what)	do {			\
 		var = (what);					\
-		printf("Estimated " fmt ": %llu ns\n", var);	\
+		ksft_print_msg("Estimated " fmt ": %llu ns\n", var);	\
 		if (var > INT_MAX)				\
 			goto more_samples;			\
 	} while (0)
@@ -218,7 +221,7 @@ int main(int argc, char *argv[])
 	ESTIMATE("seccomp per-filter overhead (filters / 4)", per_filter2,
 		 (filter2 - native - entry) / 4);
 
-	printf("Expectations:\n");
+	ksft_print_msg("Expectations:\n");
 	ret |= compare("native", "≤", "1 bitmap", native, le, bitmap1);
 	bits = compare("native", "≤", "1 filter", native, le, filter1);
 	if (bits)
@@ -230,7 +233,7 @@ int main(int argc, char *argv[])
 	bits = compare("1 bitmapped", "≈", "2 bitmapped",
 			bitmap1 - native, approx, bitmap2 - native);
 	if (bits) {
-		printf("Skipping constant action bitmap expectations: they appear unsupported.\n");
+		ksft_print_msg("Skipping constant action bitmap expectations: they appear unsupported.\n");
 		goto out;
 	}
 
@@ -242,7 +245,7 @@ int main(int argc, char *argv[])
 		goto out;
 
 more_samples:
-	printf("Saw unexpected benchmark result. Try running again with more samples?\n");
+	ksft_print_msg("Saw unexpected benchmark result. Try running again with more samples?\n");
 out:
 	return 0;
 }