[PATCH 14/14] test_firmware: add support for testing built-in firmware
From: Luis R. Rodriguez
Date: Fri Sep 17 2021 - 14:24:03 EST
From: Luis Chamberlain <mcgrof@xxxxxxxxxx>
This adds some basic knobs to let us test built-in firmware
support. We test to ensure built-in firmware is indeed used,
and that it matches the contents we expect. Likewise we test
that a file that should not be built-in was not present.
For older kernels with older test_firmware drivers (yes some
folks do test selftests this way and we support it), the new
built-in test will simply bail out early.
Reviewed-by: Borislav Petkov <bp@xxxxxxx>
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
---
drivers/base/firmware_loader/Makefile | 1 +
drivers/base/firmware_loader/builtin/Makefile | 1 +
.../firmware_loader/test-builtin/.gitignore | 3 +
.../firmware_loader/test-builtin/Makefile | 18 +++++
lib/Kconfig.debug | 34 +++++++++
lib/test_firmware.c | 52 +++++++++++++-
.../testing/selftests/firmware/fw_builtin.sh | 69 +++++++++++++++++++
tools/testing/selftests/firmware/fw_lib.sh | 7 ++
.../selftests/firmware/fw_run_tests.sh | 2 +
9 files changed, 186 insertions(+), 1 deletion(-)
create mode 100644 drivers/base/firmware_loader/test-builtin/.gitignore
create mode 100644 drivers/base/firmware_loader/test-builtin/Makefile
create mode 100755 tools/testing/selftests/firmware/fw_builtin.sh
diff --git a/drivers/base/firmware_loader/Makefile b/drivers/base/firmware_loader/Makefile
index a2dbfa19201c..1f883ea29135 100644
--- a/drivers/base/firmware_loader/Makefile
+++ b/drivers/base/firmware_loader/Makefile
@@ -1,6 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
# Makefile for the Linux firmware loader
+obj-$(CONFIG_TEST_FIRMWARE_BUILTIN) += test-builtin/
obj-$(CONFIG_FW_LOADER_BUILTIN) += builtin/
obj-$(CONFIG_FW_LOADER_USER_HELPER) += fallback_table.o
obj-$(CONFIG_FW_LOADER) += firmware_class.o
diff --git a/drivers/base/firmware_loader/builtin/Makefile b/drivers/base/firmware_loader/builtin/Makefile
index 9b0dc193f6c7..baad7777974b 100644
--- a/drivers/base/firmware_loader/builtin/Makefile
+++ b/drivers/base/firmware_loader/builtin/Makefile
@@ -2,6 +2,7 @@
include $(srctree)/drivers/base/firmware_loader/builtin/lib.Makefile
obj-y += main.o
+obj-$(CONFIG_TEST_BUILTIN_FIRMWARE) += test-builtin-firmware.bin.gen.o
# Create $(fwdir) from $(CONFIG_FW_LOADER_BUILTIN_DIR) -- if it doesn't have a
# leading /, it's relative to $(srctree).
diff --git a/drivers/base/firmware_loader/test-builtin/.gitignore b/drivers/base/firmware_loader/test-builtin/.gitignore
new file mode 100644
index 000000000000..1d46553f50a0
--- /dev/null
+++ b/drivers/base/firmware_loader/test-builtin/.gitignore
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+*.gen.S
+*.bin
diff --git a/drivers/base/firmware_loader/test-builtin/Makefile b/drivers/base/firmware_loader/test-builtin/Makefile
new file mode 100644
index 000000000000..04204ad7ede1
--- /dev/null
+++ b/drivers/base/firmware_loader/test-builtin/Makefile
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0
+include $(srctree)/drivers/base/firmware_loader/builtin/lib.Makefile
+
+extra-y := test-builtin-firmware.bin
+$(obj)/test-builtin-firmware.bin: FORCE
+ @$(kecho) " GEN $@"
+ @(set -e; \
+ ( \
+ echo 'ABCD0123'; \
+ ) > $@)
+
+# Create $(fwdir) from $(CONFIG_TEST_FIRMWARE_BUILTIN_DIR) -- if it doesn't
+# have a leading /, it's relative to $(srctree).
+fwdir := $(subst $(quote),,$(CONFIG_TEST_FIRMWARE_BUILTIN_DIR))
+fwdir := $(addprefix $(srctree)/,$(filter-out /%,$(fwdir)))$(filter /%,$(fwdir))
+
+firmware := $(addsuffix .gen.o, $(subst $(quote),,$(CONFIG_TEST_FIRMWARE_BUILTIN_FILES)))
+obj-y += $(firmware)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index b6734839a84a..9a5b6759fc36 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2333,6 +2333,40 @@ config TEST_FIRMWARE
If unsure, say N.
+config TEST_FIRMWARE_BUILTIN
+ bool "Allow building built-in test firmware"
+ depends on TEST_FIRMWARE
+ select FW_LOADER_BUILTIN
+ help
+ If enabled, firmware will be built into to the kernel so that
+ loading it with the test_firmware driver can be tested. Disabling
+ this will just mean the test firmware scripts won't find any
+ built-in firmware. Enabling this will make the kernel generate the
+ file test-builtin-firmware.bin inside local directory
+ drivers/base/firmware_loader/test-builtin. This file will then
+ be available whenever the request firmware API is used.
+
+ Enabling this functionlity essentially overrides the location where
+ you specify to find built-in firmware, and so should only be enabled
+ if you don't need to build firmware into your kernel for full
+ funcionality.
+
+ This should be disabled on production kernels as otherwise you'll
+ end up with a test firmware stuck into your final kernel image and
+ with default built-in firmware support.
+
+ If unsure, say N.
+
+config TEST_FIRMWARE_BUILTIN_FILES
+ string
+ depends on TEST_FIRMWARE_BUILTIN
+ default "test-builtin-firmware.bin"
+
+config TEST_FIRMWARE_BUILTIN_DIR
+ string
+ depends on TEST_FIRMWARE_BUILTIN
+ default "drivers/base/firmware_loader/test-builtin"
+
config TEST_SYSCTL
tristate "sysctl test driver"
depends on PROC_SYSCTL
diff --git a/lib/test_firmware.c b/lib/test_firmware.c
index 1bccd6cd5f48..134f8c78d2d4 100644
--- a/lib/test_firmware.c
+++ b/lib/test_firmware.c
@@ -34,6 +34,7 @@ MODULE_IMPORT_NS(TEST_FIRMWARE);
static DEFINE_MUTEX(test_fw_mutex);
static const struct firmware *test_firmware;
+static struct firmware builtin_test_firmware;
struct test_batched_req {
u8 idx;
@@ -58,6 +59,10 @@ struct test_batched_req {
* @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
+ * @is_builtin: used only internally to determine if the firmware was found
+ * to be built-in to the kernel using only the API call
+ * firmware_request_builtin(). We treat this specially as we are
+ * responsible for the firmware struct.
* @num_requests: number of requests to try per test case. This is trigger
* specific.
* @reqs: stores all requests information
@@ -99,6 +104,7 @@ struct test_config {
bool partial;
bool sync_direct;
bool send_uevent;
+ bool is_builtin;
u8 num_requests;
u8 read_fw_idx;
@@ -120,7 +126,11 @@ static ssize_t test_fw_misc_read(struct file *f, char __user *buf,
ssize_t rc = 0;
mutex_lock(&test_fw_mutex);
- if (test_firmware)
+ if (test_fw_config->is_builtin)
+ rc = simple_read_from_buffer(buf, size, offset,
+ builtin_test_firmware.data,
+ builtin_test_firmware.size);
+ else if (test_firmware)
rc = simple_read_from_buffer(buf, size, offset,
test_firmware->data,
test_firmware->size);
@@ -194,6 +204,7 @@ static int __test_firmware_config_init(void)
test_fw_config->buf_size = TEST_FIRMWARE_BUF_SIZE;
test_fw_config->file_offset = 0;
test_fw_config->partial = false;
+ test_fw_config->is_builtin = false;
test_fw_config->sync_direct = false;
test_fw_config->req_firmware = request_firmware;
test_fw_config->test_result = 0;
@@ -1051,6 +1062,44 @@ static ssize_t read_firmware_show(struct device *dev,
}
static DEVICE_ATTR_RO(read_firmware);
+/*
+ * In order to test this, set CONFIG_FW_LOADER_BUILTIN_FILES to a firmware file
+ * which will be built into the kernel image. Then echo the name into the
+ * "trigger_request_builtin" sysfs file of this module.
+ */
+static ssize_t trigger_request_builtin_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ int rc = -ENOENT;
+
+ if (!test_fw_config->name) {
+ pr_warn("unconfigured firmware settings\n");
+ return rc;
+ }
+
+ pr_info("loading builtin '%s'\n", test_fw_config->name);
+
+ mutex_lock(&test_fw_mutex);
+
+ if (firmware_request_builtin(&builtin_test_firmware,
+ test_fw_config->name)) {
+ /* This let's us diff against the firmware */
+ test_fw_config->is_builtin = true;
+ pr_info("loaded: %zu\n", builtin_test_firmware.size);
+ rc = count;
+ goto out;
+ }
+
+ pr_info("load of '%s' failed\n", test_fw_config->name);
+
+out:
+ mutex_unlock(&test_fw_mutex);
+
+ return rc;
+}
+static DEVICE_ATTR_WO(trigger_request_builtin);
+
#define TEST_FW_DEV_ATTR(name) &dev_attr_##name.attr
static struct attribute *test_dev_attrs[] = {
@@ -1082,6 +1131,7 @@ static struct attribute *test_dev_attrs[] = {
TEST_FW_DEV_ATTR(release_all_firmware),
TEST_FW_DEV_ATTR(test_result),
TEST_FW_DEV_ATTR(read_firmware),
+ TEST_FW_DEV_ATTR(trigger_request_builtin),
NULL,
};
diff --git a/tools/testing/selftests/firmware/fw_builtin.sh b/tools/testing/selftests/firmware/fw_builtin.sh
new file mode 100755
index 000000000000..44e4198ed88f
--- /dev/null
+++ b/tools/testing/selftests/firmware/fw_builtin.sh
@@ -0,0 +1,69 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+# Test loading built-in firmware
+set -e
+
+TEST_REQS_FW_SYSFS_FALLBACK="no"
+TEST_REQS_FW_SET_CUSTOM_PATH="yes"
+TEST_DIR=$(dirname $0)
+source $TEST_DIR/fw_lib.sh
+
+check_mods
+check_setup
+verify_reqs
+setup_tmp_file
+
+trap "test_finish" EXIT
+
+if [ "$HAS_FW_LOADER_USER_HELPER" = "yes" ]; then
+ # Turn down the timeout so failures don't take so long.
+ echo 1 >/sys/class/firmware/timeout
+fi
+
+# built-in firmware support can be optional to test
+if [[ "$HAS_FW_LOADER_BUILTIN" != "yes" || "$HAS_TEST_FIRMWARE_BUILTIN" != "yes" ]]; then
+ exit $ksft_skip
+fi
+
+echo "Testing builtin firmware API ... "
+
+config_trigger_builtin()
+{
+ echo -n 1 > $DIR/trigger_request_builtin
+}
+
+test_builtin_firmware()
+{
+ echo -n "Testing firmware_request_builtin() ... "
+ config_reset
+ config_set_name $TEST_FIRMWARE_BUILTIN_FILENAME
+ config_trigger_builtin
+ echo OK
+ # Verify the contents are what we expect.
+ echo -n "Verifying file integrity ..."
+ if ! diff -q "$FW" /dev/test_firmware >/dev/null ; then
+ echo "$0: firmware loaded content differs" >&2
+ exit 1
+ else
+ echo "firmware content matches what we expect - OK"
+ fi
+}
+
+test_builtin_firmware_nofile()
+{
+ echo -n "Testing firmware_request_builtin() with fake file... "
+ config_reset
+ config_set_name fake-${TEST_FIRMWARE_BUILTIN_FILENAME}
+ if config_trigger_builtin 2> /dev/null; then
+ echo "$0: firmware shouldn't have loaded" >&2
+ fi
+ echo "OK"
+}
+
+test_builtin_firmware
+test_builtin_firmware_nofile
+
+# Ensure test_fw_config->is_builtin is set back to false
+# otherwise we won't be able to diff against the right target
+# firmware for other tests.
+config_reset
diff --git a/tools/testing/selftests/firmware/fw_lib.sh b/tools/testing/selftests/firmware/fw_lib.sh
index 31b71fe11dc5..29949e975345 100755
--- a/tools/testing/selftests/firmware/fw_lib.sh
+++ b/tools/testing/selftests/firmware/fw_lib.sh
@@ -15,6 +15,10 @@ TEST_DIR=$(dirname $0)
# To reproduce rename this to test-firmware.bin
TEST_FIRMWARE_INTO_BUF_FILENAME=test-firmware-into-buf.bin
+# We should use a different filename for built-in firmware otherwise
+# we'd always have the file present.
+TEST_FIRMWARE_BUILTIN_FILENAME=test-builtin-firmware.bin
+
# Kselftest framework requirement - SKIP code is 4.
ksft_skip=4
@@ -63,6 +67,9 @@ check_setup()
HAS_FW_LOADER_USER_HELPER="$(kconfig_has CONFIG_FW_LOADER_USER_HELPER=y)"
HAS_FW_LOADER_USER_HELPER_FALLBACK="$(kconfig_has CONFIG_FW_LOADER_USER_HELPER_FALLBACK=y)"
HAS_FW_LOADER_COMPRESS="$(kconfig_has CONFIG_FW_LOADER_COMPRESS=y)"
+ HAS_FW_LOADER_USER_HELPER="$(kconfig_has CONFIG_FW_LOADER_USER_HELPER=y)"
+ HAS_FW_LOADER_BUILTIN="$(kconfig_has CONFIG_FW_LOADER_BUILTIN=y)"
+ HAS_TEST_FIRMWARE_BUILTIN="$(kconfig_has CONFIG_TEST_FIRMWARE_BUILTIN=y)"
PROC_FW_IGNORE_SYSFS_FALLBACK="0"
PROC_FW_FORCE_SYSFS_FALLBACK="0"
diff --git a/tools/testing/selftests/firmware/fw_run_tests.sh b/tools/testing/selftests/firmware/fw_run_tests.sh
index 777377078d5e..08a9bf043333 100755
--- a/tools/testing/selftests/firmware/fw_run_tests.sh
+++ b/tools/testing/selftests/firmware/fw_run_tests.sh
@@ -65,6 +65,8 @@ echo "Running namespace test: "
$TEST_DIR/fw_namespace $DIR/trigger_request
echo "OK"
+$TEST_DIR/fw_builtin.sh
+
if [ -f $FW_FORCE_SYSFS_FALLBACK ]; then
run_test_config_0001
run_test_config_0002
--
2.30.2