[PATCH v2 18/18] test_firmware: Test partial read support

Kees Cook
2020-07-22T19:39:26Z

From: Scott Branden <scott.branden@broadcom.com>

Add additional hooks to test_firmware to pass in support
for partial file read using request_firmware_into_buf():

buf_size: size of buffer to request firmware into
partial: indicates that a partial file request is being made
file_offset: to indicate offset into file to request

Also update firmware selftests to use the new partial read test API.

Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Co-developed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
---
This merges Scott's two test patches into one and I refactored the
selftests to not be batched, test the no-file condition, and to not
pass needless arguments, etc.
---
lib/test_firmware.c | 154 ++++++++++++++++--
.../selftests/firmware/fw_filesystem.sh | 91 +++++++++++
2 files changed, 233 insertions(+), 12 deletions(-)

diff --git a/lib/test_firmware.c b/lib/test_firmware.c
index 62af792e151c..387acb94eeea 100644
--- a/lib/test_firmware.c
+++ b/lib/test_firmware.c
@@ -50,6 +50,9 @@ struct test_batched_req {
* @name: the name of the firmware file to look for
* @into_buf: when the into_buf is used if this is true
* request_firmware_into_buf() will be used instead.
+ * @buf_size: size of buf to allocate when into_buf is true
+ * @file_offset: file offset to request when calling request_firmware_into_buf
+ * @partial: partial read opt when calling request_firmware_into_buf
* @sync_direct: when the sync trigger is used if this is true
* request_firmware_direct() will be used instead.
* @send_uevent: whether or not to send a uevent for async requests
@@ -89,6 +92,9 @@ struct test_batched_req {
struct test_config {
char *name;
bool into_buf;
+ size_t buf_size;
+ size_t file_offset;
+ bool partial;
bool sync_direct;
bool send_uevent;
u8 num_requests;
@@ -183,6 +189,9 @@ static int __test_firmware_config_init(void)
test_fw_config->num_requests = TEST_FIRMWARE_NUM_REQS;
test_fw_config->send_uevent = true;
test_fw_config->into_buf = false;
+ test_fw_config->buf_size = TEST_FIRMWARE_BUF_SIZE;
+ test_fw_config->file_offset = 0;
+ test_fw_config->partial = false;
test_fw_config->sync_direct = false;
test_fw_config->req_firmware = request_firmware;
test_fw_config->test_result = 0;
@@ -236,28 +245,35 @@ static ssize_t config_show(struct device *dev,
dev_name(dev));

if (test_fw_config->name)
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"name:\t%s\n",
test_fw_config->name);
else
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"name:\tEMTPY\n");

- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"num_requests:\t%u\n", test_fw_config->num_requests);

- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"send_uevent:\t\t%s\n",
test_fw_config->send_uevent ?
"FW_ACTION_HOTPLUG" :
"FW_ACTION_NOHOTPLUG");
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"into_buf:\t\t%s\n",
test_fw_config->into_buf ? "true" : "false");
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "buf_size:\t%zu\n", test_fw_config->buf_size);
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "file_offset:\t%zu\n", test_fw_config->file_offset);
+ len += scnprintf(buf + len, PAGE_SIZE - len,
+ "partial:\t\t%s\n",
+ test_fw_config->partial ? "true" : "false");
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"sync_direct:\t\t%s\n",
test_fw_config->sync_direct ? "true" : "false");
- len += scnprintf(buf+len, PAGE_SIZE - len,
+ len += scnprintf(buf + len, PAGE_SIZE - len,
"read_fw_idx:\t%u\n", test_fw_config->read_fw_idx);

mutex_unlock(&test_fw_mutex);
@@ -315,6 +331,30 @@ static ssize_t test_dev_config_show_bool(char *buf, bool val)
return snprintf(buf, PAGE_SIZE, "%d\n", val);
}

+static int test_dev_config_update_size_t(const char *buf,
+ size_t size,
+ size_t *cfg)
+{
+ int ret;
+ long new;
+
+ ret = kstrtol(buf, 10, &new);
+ if (ret)
+ return ret;
+
+ mutex_lock(&test_fw_mutex);
+ *(size_t *)cfg = new;
+ mutex_unlock(&test_fw_mutex);
+
+ /* Always return full write size even if we didn't consume all */
+ return size;
+}
+
+static ssize_t test_dev_config_show_size_t(char *buf, size_t val)
+{
+ return snprintf(buf, PAGE_SIZE, "%zu\n", val);
+}
+
static ssize_t test_dev_config_show_int(char *buf, int val)
{
return snprintf(buf, PAGE_SIZE, "%d\n", val);
@@ -400,6 +440,83 @@ static ssize_t config_into_buf_show(struct device *dev,
}
static DEVICE_ATTR_RW(config_into_buf);

+static ssize_t config_buf_size_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int rc;
+
+ mutex_lock(&test_fw_mutex);
+ if (test_fw_config->reqs) {
+ pr_err("Must call release_all_firmware prior to changing config\n");
+ rc = -EINVAL;
+ mutex_unlock(&test_fw_mutex);
+ goto out;
+ }
+ mutex_unlock(&test_fw_mutex);
+
+ rc = test_dev_config_update_size_t(buf, count,
+ &test_fw_config->buf_size);
+
+out:
+ return rc;
+}
+
+static ssize_t config_buf_size_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return test_dev_config_show_size_t(buf, test_fw_config->buf_size);
+}
+static DEVICE_ATTR_RW(config_buf_size);
+
+static ssize_t config_file_offset_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int rc;
+
+ mutex_lock(&test_fw_mutex);
+ if (test_fw_config->reqs) {
+ pr_err("Must call release_all_firmware prior to changing config\n");
+ rc = -EINVAL;
+ mutex_unlock(&test_fw_mutex);
+ goto out;
+ }
+ mutex_unlock(&test_fw_mutex);
+
+ rc = test_dev_config_update_size_t(buf, count,
+ &test_fw_config->file_offset);
+
+out:
+ return rc;
+}
+
+static ssize_t config_file_offset_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return test_dev_config_show_size_t(buf, test_fw_config->file_offset);
+}
+static DEVICE_ATTR_RW(config_file_offset);
+
+static ssize_t config_partial_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ return test_dev_config_update_bool(buf,
+ count,
+ &test_fw_config->partial);
+}
+
+static ssize_t config_partial_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ return test_dev_config_show_bool(buf, test_fw_config->partial);
+}
+static DEVICE_ATTR_RW(config_partial);
+
static ssize_t config_sync_direct_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
@@ -655,11 +772,21 @@ static int test_fw_run_batch_request(void *data)
if (!test_buf)
return -ENOSPC;

- req->rc = request_firmware_into_buf(&req->fw,
- req->name,
- req->dev,
- test_buf,
- TEST_FIRMWARE_BUF_SIZE);
+ if (test_fw_config->partial)
+ req->rc = request_partial_firmware_into_buf
+ (&req->fw,
+ req->name,
+ req->dev,
+ test_buf,
+ test_fw_config->buf_size,
+ test_fw_config->file_offset);
+ else
+ req->rc = request_firmware_into_buf
+ (&req->fw,
+ req->name,
+ req->dev,
+ test_buf,
+ test_fw_config->buf_size);
if (!req->fw)
kfree(test_buf);
} else {
@@ -932,6 +1059,9 @@ static struct attribute *test_dev_attrs[] = {
TEST_FW_DEV_ATTR(config_name),
TEST_FW_DEV_ATTR(config_num_requests),
TEST_FW_DEV_ATTR(config_into_buf),
+ TEST_FW_DEV_ATTR(config_buf_size),
+ TEST_FW_DEV_ATTR(config_file_offset),
+ TEST_FW_DEV_ATTR(config_partial),
TEST_FW_DEV_ATTR(config_sync_direct),
TEST_FW_DEV_ATTR(config_send_uevent),
TEST_FW_DEV_ATTR(config_read_fw_idx),
diff --git a/tools/testing/selftests/firmware/fw_filesystem.sh b/tools/testing/selftests/firmware/fw_filesystem.sh
index fcc281373b4d..c2a2a100114b 100755
--- a/tools/testing/selftests/firmware/fw_filesystem.sh
+++ b/tools/testing/selftests/firmware/fw_filesystem.sh
@@ -149,6 +149,26 @@ config_unset_into_buf()
echo 0 > $DIR/config_into_buf
}

+config_set_buf_size()
+{
+ echo $1 > $DIR/config_buf_size
+}
+
+config_set_file_offset()
+{
+ echo $1 > $DIR/config_file_offset
+}
+
+config_set_partial()
+{
+ echo 1 > $DIR/config_partial
+}
+
+config_unset_partial()
+{
+ echo 0 > $DIR/config_partial
+}
+
config_set_sync_direct()
{
echo 1 > $DIR/config_sync_direct
@@ -207,6 +227,35 @@ read_firmwares()
done
}

+read_partial_firmwares()
+{
+ if [ "$(cat $DIR/config_into_buf)" == "1" ]; then
+ fwfile="${FW_INTO_BUF}"
+ else
+ fwfile="${FW}"
+ fi
+
+ if [ "$1" = "xzonly" ]; then
+ fwfile="${fwfile}-orig"
+ fi
+
+ # Strip fwfile down to match partial offset and length
+ partial_data="$(cat $fwfile)"
+ partial_data="${partial_data:$2:$3}"
+
+ for i in $(seq 0 3); do
+ config_set_read_fw_idx $i
+
+ read_firmware="$(cat $DIR/read_firmware)"
+
+ # Verify the contents are what we expect.
+ if [ $read_firmware != $partial_data ]; then
+ echo "request #$i: partial firmware was not loaded" >&2
+ exit 1
+ fi
+ done
+}
+
read_firmwares_expect_nofile()
{
for i in $(seq 0 3); do
@@ -242,6 +291,21 @@ test_batched_request_firmware_into_buf_nofile()
echo "OK"
}

+test_request_partial_firmware_into_buf_nofile()
+{
+ echo -n "Test request_partial_firmware_into_buf() off=$1 size=$2 nofile: "
+ config_reset
+ config_set_name nope-test-firmware.bin
+ config_set_into_buf
+ config_set_partial
+ config_set_buf_size $2
+ config_set_file_offset $1
+ config_trigger_sync
+ read_firmwares_expect_nofile
+ release_all_firmware
+ echo "OK"
+}
+
test_batched_request_firmware_direct_nofile()
{
echo -n "Batched request_firmware_direct() nofile try #$1: "
@@ -356,6 +420,21 @@ test_request_firmware_nowait_custom()
echo "OK"
}

+test_request_partial_firmware_into_buf()
+{
+ echo -n "Test request_partial_firmware_into_buf() off=$1 size=$2: "
+ config_reset
+ config_set_name $TEST_FIRMWARE_INTO_BUF_FILENAME
+ config_set_into_buf
+ config_set_partial
+ config_set_buf_size $2
+ config_set_file_offset $1
+ config_trigger_sync
+ read_partial_firmwares normal $1 $2
+ release_all_firmware
+ echo "OK"
+}
+
# Only continue if batched request triggers are present on the
# test-firmware driver
test_config_present
@@ -383,6 +462,12 @@ for i in $(seq 1 5); do
test_request_firmware_nowait_custom $i normal
done

+# Partial loads cannot use fallback, so do not repeat tests.
+test_request_partial_firmware_into_buf 0 10
+test_request_partial_firmware_into_buf 0 5
+test_request_partial_firmware_into_buf 1 6
+test_request_partial_firmware_into_buf 2 10
+
# Test for file not found, errors are expected, the failure would be
# a hung task, which would require a hard reset.
echo
@@ -407,6 +492,12 @@ for i in $(seq 1 5); do
test_request_firmware_nowait_custom_nofile $i
done

+# Partial loads cannot use fallback, so do not repeat tests.
+test_request_partial_firmware_into_buf_nofile 0 10
+test_request_partial_firmware_into_buf_nofile 0 5
+test_request_partial_firmware_into_buf_nofile 1 6
+test_request_partial_firmware_into_buf_nofile 2 10
+
test "$HAS_FW_LOADER_COMPRESS" != "yes" && exit 0

# test with both files present