1 files changed, 353 insertions, 59 deletions

diff --git a/tools/testing/selftests/powerpc/utils.c b/tools/testing/selftests/powerpc/utils.c
index 1f36ee1a909a..7c8cfedb012a 100644
--- a/tools/testing/selftests/powerpc/utils.c
+++ b/tools/testing/selftests/powerpc/utils.c
@@ -8,6 +8,8 @@
 #include <elf.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <inttypes.h>
+#include <limits.h>
 #include <link.h>
 #include <sched.h>
 #include <stdio.h>
@@ -26,34 +28,360 @@
 
 static char auxv[4096];
 
-int read_auxv(char *buf, ssize_t buf_size)
+int read_file(const char *path, char *buf, size_t count, size_t *len)
 {
-	ssize_t num;
-	int rc, fd;
+	ssize_t rc;
+	int fd;
+	int err;
+	char eof;
 
-	fd = open("/proc/self/auxv", O_RDONLY);
-	if (fd == -1) {
-		perror("open");
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
 		return -errno;
+
+	rc = read(fd, buf, count);
+	if (rc < 0) {
+		err = -errno;
+		goto out;
 	}
 
-	num = read(fd, buf, buf_size);
-	if (num < 0) {
-		perror("read");
-		rc = -EIO;
+	if (len)
+		*len = rc;
+
+	/* Overflow if there are still more bytes after filling the buffer */
+	if (rc == count) {
+		rc = read(fd, &eof, 1);
+		if (rc != 0) {
+			err = -EOVERFLOW;
+			goto out;
+		}
+	}
+
+	err = 0;
+
+out:
+	close(fd);
+	errno = -err;
+	return err;
+}
+
+int read_file_alloc(const char *path, char **buf, size_t *len)
+{
+	size_t read_offset = 0;
+	size_t buffer_len = 0;
+	char *buffer = NULL;
+	int err;
+	int fd;
+
+	fd = open(path, O_RDONLY);
+	if (fd < 0)
+		return -errno;
+
+	/*
+	 * We don't use stat & preallocate st_size because some non-files
+	 * report 0 file size. Instead just dynamically grow the buffer
+	 * as needed.
+	 */
+	while (1) {
+		ssize_t rc;
+
+		if (read_offset >= buffer_len / 2) {
+			char *next_buffer;
+
+			buffer_len = buffer_len ? buffer_len * 2 : 4096;
+			next_buffer = realloc(buffer, buffer_len);
+			if (!next_buffer) {
+				err = -errno;
+				goto out;
+			}
+			buffer = next_buffer;
+		}
+
+		rc = read(fd, buffer + read_offset, buffer_len - read_offset);
+		if (rc < 0) {
+			err = -errno;
+			goto out;
+		}
+
+		if (rc == 0)
+			break;
+
+		read_offset += rc;
+	}
+
+	*buf = buffer;
+	if (len)
+		*len = read_offset;
+
+	err = 0;
+
+out:
+	close(fd);
+	if (err)
+		free(buffer);
+	errno = -err;
+	return err;
+}
+
+int write_file(const char *path, const char *buf, size_t count)
+{
+	int fd;
+	int err;
+	ssize_t rc;
+
+	fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+	if (fd < 0)
+		return -errno;
+
+	rc = write(fd, buf, count);
+	if (rc < 0) {
+		err = -errno;
 		goto out;
 	}
 
-	if (num > buf_size) {
-		printf("overflowed auxv buffer\n");
-		rc = -EOVERFLOW;
+	if (rc != count) {
+		err = -EOVERFLOW;
 		goto out;
 	}
 
-	rc = 0;
+	err = 0;
+
 out:
 	close(fd);
-	return rc;
+	errno = -err;
+	return err;
+}
+
+int read_auxv(char *buf, ssize_t buf_size)
+{
+	int err;
+
+	err = read_file("/proc/self/auxv", buf, buf_size, NULL);
+	if (err) {
+		perror("Error reading /proc/self/auxv");
+		return err;
+	}
+
+	return 0;
+}
+
+int read_debugfs_file(const char *subpath, char *buf, size_t count)
+{
+	char path[PATH_MAX] = "/sys/kernel/debug/";
+
+	strncat(path, subpath, sizeof(path) - strlen(path) - 1);
+
+	return read_file(path, buf, count, NULL);
+}
+
+int write_debugfs_file(const char *subpath, const char *buf, size_t count)
+{
+	char path[PATH_MAX] = "/sys/kernel/debug/";
+
+	strncat(path, subpath, sizeof(path) - strlen(path) - 1);
+
+	return write_file(path, buf, count);
+}
+
+static int validate_int_parse(const char *buffer, size_t count, char *end)
+{
+	int err = 0;
+
+	/* Require at least one digit */
+	if (end == buffer) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	/* Require all remaining characters be whitespace-ish */
+	for (; end < buffer + count; end++) {
+		if (*end == '\0')
+			break;
+
+		if (*end != ' ' && *end != '\n') {
+			err = -EINVAL;
+			goto out;
+		}
+	}
+
+out:
+	errno = -err;
+	return err;
+}
+
+static int parse_bounded_int(const char *buffer, size_t count, intmax_t *result,
+			     int base, intmax_t min, intmax_t max)
+{
+	int err;
+	char *end;
+
+	errno = 0;
+	*result = strtoimax(buffer, &end, base);
+
+	if (errno)
+		return -errno;
+
+	err = validate_int_parse(buffer, count, end);
+	if (err)
+		goto out;
+
+	if (*result < min || *result > max)
+		err = -EOVERFLOW;
+
+out:
+	errno = -err;
+	return err;
+}
+
+static int parse_bounded_uint(const char *buffer, size_t count, uintmax_t *result,
+			      int base, uintmax_t max)
+{
+	int err = 0;
+	char *end;
+
+	errno = 0;
+	*result = strtoumax(buffer, &end, base);
+
+	if (errno)
+		return -errno;
+
+	err = validate_int_parse(buffer, count, end);
+	if (err)
+		goto out;
+
+	if (*result > max)
+		err = -EOVERFLOW;
+
+out:
+	errno = -err;
+	return err;
+}
+
+int parse_intmax(const char *buffer, size_t count, intmax_t *result, int base)
+{
+	return parse_bounded_int(buffer, count, result, base, INTMAX_MIN, INTMAX_MAX);
+}
+
+int parse_uintmax(const char *buffer, size_t count, uintmax_t *result, int base)
+{
+	return parse_bounded_uint(buffer, count, result, base, UINTMAX_MAX);
+}
+
+int parse_int(const char *buffer, size_t count, int *result, int base)
+{
+	intmax_t parsed;
+	int err = parse_bounded_int(buffer, count, &parsed, base, INT_MIN, INT_MAX);
+
+	*result = parsed;
+	return err;
+}
+
+int parse_uint(const char *buffer, size_t count, unsigned int *result, int base)
+{
+	uintmax_t parsed;
+	int err = parse_bounded_uint(buffer, count, &parsed, base, UINT_MAX);
+
+	*result = parsed;
+	return err;
+}
+
+int parse_long(const char *buffer, size_t count, long *result, int base)
+{
+	intmax_t parsed;
+	int err = parse_bounded_int(buffer, count, &parsed, base, LONG_MIN, LONG_MAX);
+
+	*result = parsed;
+	return err;
+}
+
+int parse_ulong(const char *buffer, size_t count, unsigned long *result, int base)
+{
+	uintmax_t parsed;
+	int err = parse_bounded_uint(buffer, count, &parsed, base, ULONG_MAX);
+
+	*result = parsed;
+	return err;
+}
+
+int read_long(const char *path, long *result, int base)
+{
+	int err;
+	char buffer[32] = {0};
+
+	err = read_file(path, buffer, sizeof(buffer) - 1, NULL);
+	if (err)
+		return err;
+
+	return parse_long(buffer, sizeof(buffer), result, base);
+}
+
+int read_ulong(const char *path, unsigned long *result, int base)
+{
+	int err;
+	char buffer[32] = {0};
+
+	err = read_file(path, buffer, sizeof(buffer) - 1, NULL);
+	if (err)
+		return err;
+
+	return parse_ulong(buffer, sizeof(buffer), result, base);
+}
+
+int write_long(const char *path, long result, int base)
+{
+	int err;
+	int len;
+	char buffer[32];
+
+	/* Decimal only for now: no format specifier for signed hex values */
+	if (base != 10) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	len = snprintf(buffer, sizeof(buffer), "%ld", result);
+	if (len < 0 || len >= sizeof(buffer)) {
+		err = -EOVERFLOW;
+		goto out;
+	}
+
+	err = write_file(path, buffer, len);
+
+out:
+	errno = -err;
+	return err;
+}
+
+int write_ulong(const char *path, unsigned long result, int base)
+{
+	int err;
+	int len;
+	char buffer[32];
+	char *fmt;
+
+	switch (base) {
+	case 10:
+		fmt = "%lu";
+		break;
+	case 16:
+		fmt = "%lx";
+		break;
+	default:
+		err = -EINVAL;
+		goto out;
+	}
+
+	len = snprintf(buffer, sizeof(buffer), fmt, result);
+	if (len < 0 || len >= sizeof(buffer)) {
+		err = -errno;
+		goto out;
+	}
+
+	err = write_file(path, buffer, len);
+
+out:
+	errno = -err;
+	return err;
 }
 
 void *find_auxv_entry(int type, char *auxv)
@@ -142,65 +470,31 @@ bool is_ppc64le(void)
 int read_sysfs_file(char *fpath, char *result, size_t result_size)
 {
 	char path[PATH_MAX] = "/sys/";
-	int rc = -1, fd;
 
 	strncat(path, fpath, PATH_MAX - strlen(path) - 1);
 
-	if ((fd = open(path, O_RDONLY)) < 0)
-		return rc;
-
-	rc = read(fd, result, result_size);
-
-	close(fd);
-
-	if (rc < 0)
-		return rc;
-
-	return 0;
+	return read_file(path, result, result_size, NULL);
 }
 
-int read_debugfs_file(char *debugfs_file, int *result)
+int read_debugfs_int(const char *debugfs_file, int *result)
 {
-	int rc = -1, fd;
-	char path[PATH_MAX];
-	char value[16];
-
-	strcpy(path, "/sys/kernel/debug/");
-	strncat(path, debugfs_file, PATH_MAX - strlen(path) - 1);
+	int err;
+	char value[16] = {0};
 
-	if ((fd = open(path, O_RDONLY)) < 0)
-		return rc;
+	err = read_debugfs_file(debugfs_file, value, sizeof(value) - 1);
+	if (err)
+		return err;
 
-	if ((rc = read(fd, value, sizeof(value))) < 0)
-		return rc;
-
-	value[15] = 0;
-	*result = atoi(value);
-	close(fd);
-
-	return 0;
+	return parse_int(value, sizeof(value), result, 10);
 }
 
-int write_debugfs_file(char *debugfs_file, int result)
+int write_debugfs_int(const char *debugfs_file, int result)
 {
-	int rc = -1, fd;
-	char path[PATH_MAX];
 	char value[16];
 
-	strcpy(path, "/sys/kernel/debug/");
-	strncat(path, debugfs_file, PATH_MAX - strlen(path) - 1);
-
-	if ((fd = open(path, O_WRONLY)) < 0)
-		return rc;
-
 	snprintf(value, 16, "%d", result);
 
-	if ((rc = write(fd, value, strlen(value))) < 0)
-		return rc;
-
-	close(fd);
-
-	return 0;
+	return write_debugfs_file(debugfs_file, value, strlen(value));
 }
 
 static long perf_event_open(struct perf_event_attr *hw_event, pid_t pid,