1 files changed, 144 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/unpriv_helpers.c b/tools/testing/selftests/bpf/unpriv_helpers.c
new file mode 100644
index 000000000000..f997d7ec8fd0
--- /dev/null
+++ b/tools/testing/selftests/bpf/unpriv_helpers.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <errno.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/utsname.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <zlib.h>
+
+#include "unpriv_helpers.h"
+
+static gzFile open_config(void)
+{
+	struct utsname uts;
+	char buf[PATH_MAX];
+	gzFile config;
+
+	if (uname(&uts)) {
+		perror("uname");
+		goto config_gz;
+	}
+
+	snprintf(buf, sizeof(buf), "/boot/config-%s", uts.release);
+	config = gzopen(buf, "rb");
+	if (config)
+		return config;
+	fprintf(stderr, "gzopen %s: %s\n", buf, strerror(errno));
+
+config_gz:
+	config = gzopen("/proc/config.gz", "rb");
+	if (!config)
+		perror("gzopen /proc/config.gz");
+	return config;
+}
+
+static int config_contains(const char *pat)
+{
+	const char *msg;
+	char buf[1024];
+	gzFile config;
+	int n, err;
+
+	config = open_config();
+	if (!config)
+		return -1;
+
+	for (;;) {
+		if (!gzgets(config, buf, sizeof(buf))) {
+			msg = gzerror(config, &err);
+			if (err == Z_ERRNO)
+				perror("gzgets /proc/config.gz");
+			else if (err != Z_OK)
+				fprintf(stderr, "gzgets /proc/config.gz: %s", msg);
+			gzclose(config);
+			return -1;
+		}
+		n = strlen(buf);
+		if (buf[n - 1] == '\n')
+			buf[n - 1] = 0;
+		if (strcmp(buf, pat) == 0) {
+			gzclose(config);
+			return 1;
+		}
+	}
+	gzclose(config);
+	return 0;
+}
+
+static bool cmdline_contains(const char *pat)
+{
+	char cmdline[4096], *c;
+	int fd, ret = false;
+
+	fd = open("/proc/cmdline", O_RDONLY);
+	if (fd < 0) {
+		perror("open /proc/cmdline");
+		return false;
+	}
+
+	if (read(fd, cmdline, sizeof(cmdline) - 1) < 0) {
+		perror("read /proc/cmdline");
+		goto out;
+	}
+
+	cmdline[sizeof(cmdline) - 1] = '\0';
+	for (c = strtok(cmdline, " \n"); c; c = strtok(NULL, " \n")) {
+		if (strncmp(c, pat, strlen(c)))
+			continue;
+		ret = true;
+		break;
+	}
+out:
+	close(fd);
+	return ret;
+}
+
+static int get_mitigations_off(void)
+{
+	int enabled_in_config;
+
+	if (cmdline_contains("mitigations=off"))
+		return 1;
+	enabled_in_config = config_contains("CONFIG_CPU_MITIGATIONS=y");
+	if (enabled_in_config < 0)
+		return -1;
+	return !enabled_in_config;
+}
+
+bool get_unpriv_disabled(void)
+{
+	int mitigations_off;
+	bool disabled;
+	char buf[2];
+	FILE *fd;
+
+	fd = fopen("/proc/sys/" UNPRIV_SYSCTL, "r");
+	if (fd) {
+		disabled = (fgets(buf, 2, fd) == buf && atoi(buf));
+		fclose(fd);
+	} else {
+		perror("fopen /proc/sys/" UNPRIV_SYSCTL);
+		disabled = true;
+	}
+
+	if (disabled)
+		return true;
+
+	/*
+	 * Some unpriv tests rely on spectre mitigations being on.
+	 * If mitigations are off or status can't be determined
+	 * assume that unpriv tests are disabled.
+	 */
+	mitigations_off = get_mitigations_off();
+	if (mitigations_off < 0) {
+		fprintf(stderr,
+			"Can't determine if mitigations are enabled, disabling unpriv tests.");
+		return true;
+	}
+	return mitigations_off;
+}