1 files changed, 105 insertions, 0 deletions
diff --git a/tools/testing/selftests/exec/load_address.c b/tools/testing/selftests/exec/load_address.c
new file mode 100644
index 000000000000..8257fddba8c8
--- /dev/null
+++ b/tools/testing/selftests/exec/load_address.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#ifndef _GNU_SOURCE
+#define _GNU_SOURCE
+#endif
+#include <link.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include "../kselftest.h"
+
+struct Statistics {
+	unsigned long long load_address;
+	unsigned long long alignment;
+	bool interp;
+};
+
+int ExtractStatistics(struct dl_phdr_info *info, size_t size, void *data)
+{
+	struct Statistics *stats = (struct Statistics *) data;
+	int i;
+
+	if (info->dlpi_name != NULL && info->dlpi_name[0] != '\0') {
+		// Ignore headers from other than the executable.
+		return 2;
+	}
+
+	stats->load_address = (unsigned long long) info->dlpi_addr;
+	stats->alignment = 0;
+
+	for (i = 0; i < info->dlpi_phnum; i++) {
+		unsigned long long align;
+
+		if (info->dlpi_phdr[i].p_type == PT_INTERP) {
+			stats->interp = true;
+			continue;
+		}
+
+		if (info->dlpi_phdr[i].p_type != PT_LOAD)
+			continue;
+
+		align = info->dlpi_phdr[i].p_align;
+
+		if (align > stats->alignment)
+			stats->alignment = align;
+	}
+
+	return 1;  // Terminate dl_iterate_phdr.
+}
+
+int main(int argc, char **argv)
+{
+	struct Statistics extracted = { };
+	unsigned long long misalign, pow2;
+	bool interp_needed;
+	char buf[1024];
+	FILE *maps;
+	int ret;
+
+	ksft_print_header();
+	ksft_set_plan(4);
+
+	/* Dump maps file for debugging reference. */
+	maps = fopen("/proc/self/maps", "r");
+	if (!maps)
+		ksft_exit_fail_msg("FAILED: /proc/self/maps: %s\n", strerror(errno));
+	while (fgets(buf, sizeof(buf), maps)) {
+		ksft_print_msg("%s", buf);
+	}
+	fclose(maps);
+
+	/* Walk the program headers. */
+	ret = dl_iterate_phdr(ExtractStatistics, &extracted);
+	if (ret != 1)
+		ksft_exit_fail_msg("FAILED: dl_iterate_phdr\n");
+
+	/* Report our findings. */
+	ksft_print_msg("load_address=%#llx alignment=%#llx\n",
+		       extracted.load_address, extracted.alignment);
+
+	/* If we're named with ".static." we expect no INTERP. */
+	interp_needed = strstr(argv[0], ".static.") == NULL;
+
+	/* Were we built as expected? */
+	ksft_test_result(interp_needed == extracted.interp,
+			 "%s INTERP program header %s\n",
+			 interp_needed ? "Wanted" : "Unwanted",
+			 extracted.interp ? "seen" : "missing");
+
+	/* Did we find an alignment? */
+	ksft_test_result(extracted.alignment != 0,
+			 "Alignment%s found\n", extracted.alignment ? "" : " NOT");
+
+	/* Is the alignment sane? */
+	pow2 = extracted.alignment & (extracted.alignment - 1);
+	ksft_test_result(pow2 == 0,
+			 "Alignment is%s a power of 2: %#llx\n",
+			 pow2 == 0 ? "" : " NOT", extracted.alignment);
+
+	/* Is the load address aligned? */
+	misalign = extracted.load_address & (extracted.alignment - 1);
+	ksft_test_result(misalign == 0, "Load Address is %saligned (%#llx)\n",
+			 misalign ? "MIS" : "", misalign);
+
+	ksft_finished();
+}