1 files changed, 119 insertions, 0 deletions
diff --git a/tests/bugs/write-behind/bug-1058663.c b/tests/bugs/write-behind/bug-1058663.c
new file mode 100644
index 00000000000..5e522e98048
--- /dev/null
+++ b/tests/bugs/write-behind/bug-1058663.c
@@ -0,0 +1,119 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdint.h>
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <sys/mman.h>
+#include <signal.h>
+
+#define FILE_SIZE 1048576
+
+/* number of tests to run */
+#define RUN_LOOP 1000
+
+/* number of SIGBUS before exiting */
+#define MAX_SIGBUS 1
+static int expect_sigbus;
+static int sigbus_received;
+
+/* test for truncate()/seek()/write()/mmap()
+ * There should ne no SIGBUS triggered.
+ */
+void seek_write(char *filename)
+{
+	int fd;
+	uint8_t *map;
+	int i;
+
+	fd = open(filename, O_RDWR|O_CREAT|O_TRUNC, 0600);
+	lseek(fd, FILE_SIZE - 1, SEEK_SET);
+	write(fd, "\xff", 1);
+
+	map = mmap(NULL, FILE_SIZE, PROT_READ, MAP_PRIVATE, fd, 0);
+	for (i = 0; i < (FILE_SIZE - 1); i++) {
+		if (map[i] != 0) /* should never be true */
+			abort();
+	}
+	munmap(map, FILE_SIZE);
+
+	close(fd);
+}
+
+int read_after_eof(char *filename)
+{
+	int ret = 0;
+	int fd;
+	char *data;
+	uint8_t *map;
+
+	fd = open(filename, O_RDWR|O_CREAT|O_TRUNC, 0600);
+	lseek(fd, FILE_SIZE - 1, SEEK_SET);
+	write(fd, "\xff", 1);
+
+	/* trigger verify that reading after EOF fails */
+	ret = read(fd, data, FILE_SIZE / 2);
+	if (ret != 0)
+		return 1;
+
+	/* map an area of 1 byte after FILE_SIZE */
+	map = mmap(NULL, 1, PROT_READ, MAP_PRIVATE, fd, FILE_SIZE);
+	/* map[0] is an access after EOF, it should trigger SIGBUS */
+	if (map[0] != 0)
+		/* it is expected that we exit before we get here */
+		if (!sigbus_received)
+			return 1;
+	munmap(map, FILE_SIZE);
+
+	close(fd);
+
+	return ret;
+}
+
+/* signal handler for SIGBUS */
+void catch_sigbus(int signum)
+{
+	switch (signum) {
+#ifdef __NetBSD__
+	/* Depending on architecture, we can get SIGSEGV */
+	case SIGSEGV: /* FALLTHROUGH */
+#endif
+	case SIGBUS:
+		sigbus_received++;
+		if (!expect_sigbus)
+			exit(EXIT_FAILURE);
+		if (sigbus_received >= MAX_SIGBUS)
+			exit(EXIT_SUCCESS);
+		break;
+	default:
+		printf("Unexpected signal received: %d\n", signum);
+	}
+}
+
+int main(int argc, char **argv)
+{
+	int i = 0;
+
+	if (argc == 1) {
+		printf("Usage: %s <filename>\n", argv[0]);
+		return EXIT_FAILURE;
+	}
+
+#ifdef __NetBSD__
+	/* Depending on architecture, we can get SIGSEGV */
+	signal(SIGSEGV, catch_sigbus);
+#endif
+	signal(SIGBUS, catch_sigbus);
+
+	/* the next test should not trigger SIGBUS */
+	expect_sigbus = 0;
+	for (i = 0; i < RUN_LOOP; i++) {
+		seek_write(argv[1]);
+	}
+
+	/* the next test should trigger SIGBUS */
+	expect_sigbus = 1;
+	if (read_after_eof(argv[1]))
+		return EXIT_FAILURE;
+
+	return EXIT_SUCCESS;
+}