[7/8] firewire: core: detect model name for legacy layout of configuration ROM
Commit Message
As the part of support for legacy layout of configuration ROM, this
commit traverses vendor directory as well as root directory when showing
device attribute for node device. This change expects 'model_name'
attribute appears in node device, however it is probable to see the other
types of descriptor leaf if the vendor directory includes.
Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
---
drivers/firewire/core-device.c | 31 ++++++++++++++++++------
drivers/firewire/device-attribute-test.c | 5 ++--
2 files changed, 27 insertions(+), 9 deletions(-)
Comments
Hi,
> - ret = fw_csr_string(dir, attr->key, buf, bufsize);
> + for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) {
> + int result = fw_csr_string(directories[i], attr->key, buf, bufsize);
> + // Detected.
> + if (result >= 0)
> + ret = result;
> + }
>
> if (ret >= 0) {
ret is an automatic variable with no initializer. Unless you initialize
it (to -ENOENT), this is UB.
-- Adam
Hi,
On Thu, Dec 21, 2023 at 04:50:08AM -0800, Adam Goldman wrote:
> Hi,
>
> > - ret = fw_csr_string(dir, attr->key, buf, bufsize);
> > + for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) {
> > + int result = fw_csr_string(directories[i], attr->key, buf, bufsize);
> > + // Detected.
> > + if (result >= 0)
> > + ret = result;
> > + }
> >
> > if (ret >= 0) {
>
> ret is an automatic variable with no initializer. Unless you initialize
> it (to -ENOENT), this is UB.
Indeed. The uninitialized value is going to be evaluated. I'll send take
2 patchset later.
Thanks
Takashi Sakamoto
@@ -317,17 +317,29 @@ static ssize_t show_text_leaf(struct device *dev,
{
struct config_rom_attribute *attr =
container_of(dattr, struct config_rom_attribute, attr);
- const u32 *dir;
+ const u32 *directories[] = {NULL, NULL};
size_t bufsize;
char dummy_buf[2];
- int ret;
+ int i, ret;
down_read(&fw_device_rwsem);
- if (is_fw_unit(dev))
- dir = fw_unit(dev)->directory;
- else
- dir = fw_device(dev)->config_rom + ROOT_DIR_OFFSET;
+ if (is_fw_unit(dev)) {
+ directories[0] = fw_unit(dev)->directory;
+ } else {
+ const u32 *root_directory = fw_device(dev)->config_rom + ROOT_DIR_OFFSET;
+ const u32 *vendor_directory = search_directory(root_directory, CSR_VENDOR);
+
+ if (!vendor_directory) {
+ directories[0] = root_directory;
+ } else {
+ // Legacy layout of configuration ROM described in Annex 1 of
+ // 'Configuration ROM for AV/C Devices 1.0 (December 12, 2000, 1394
+ // Trading Association, TA Document 1999027)'.
+ directories[0] = root_directory;
+ directories[1] = vendor_directory;
+ }
+ }
if (buf) {
bufsize = PAGE_SIZE - 1;
@@ -336,7 +348,12 @@ static ssize_t show_text_leaf(struct device *dev,
bufsize = 1;
}
- ret = fw_csr_string(dir, attr->key, buf, bufsize);
+ for (i = 0; i < ARRAY_SIZE(directories) && !!directories[i]; ++i) {
+ int result = fw_csr_string(directories[i], attr->key, buf, bufsize);
+ // Detected.
+ if (result >= 0)
+ ret = result;
+ }
if (ret >= 0) {
/* Strip trailing whitespace and add newline. */
@@ -206,8 +206,9 @@ static void device_attr_legacy_avc(struct kunit *test)
// Descriptor leaf entry for vendor is not found.
KUNIT_EXPECT_LT(test, show_text_leaf(node_dev, &config_rom_attributes[5].attr, buf), 0);
- // Descriptor leaf entry for model is not found.
- KUNIT_EXPECT_LT(test, show_text_leaf(node_dev, &config_rom_attributes[6].attr, buf), 0);
+ // Descriptor leaf entry for model is found.
+ KUNIT_EXPECT_GT(test, show_text_leaf(node_dev, &config_rom_attributes[6].attr, buf), 0);
+ KUNIT_EXPECT_STREQ(test, buf, "ABCDEFGHIJ\n");
// For entries in unit 0 directory.