On 2022/01/02 16:08, Dmitry Osipenko wrote:
> 26.12.2021 18:35, Hector Martin пишет:
>> +static void brcm_free_alt_fw_paths(const char **alt_paths)
>> +{
>> + int i;
>> +
>> + if (!alt_paths)
>> + return;
>> +
>> + for (i = 0; alt_paths[i]; i++)
>> + kfree(alt_paths[i]);
>> +
>> + kfree(alt_paths);
>> }
>>
>> static int brcmf_fw_request_firmware(const struct firmware **fw,
>> struct brcmf_fw *fwctx)
>> {
>> struct brcmf_fw_item *cur = &fwctx->req->items[fwctx->curpos];
>> - int ret;
>> + int ret, i;
>>
>> /* Files can be board-specific, first try a board-specific path */
>> if (cur->type == BRCMF_FW_TYPE_NVRAM && fwctx->req->board_type) {
>> - char *alt_path;
>> + const char **alt_paths = brcm_alt_fw_paths(cur->path, fwctx);
>>
>> - alt_path = brcm_alt_fw_path(cur->path, fwctx->req->board_type);
>> - if (!alt_path)
>> + if (!alt_paths)
>> goto fallback;
>>
>> - ret = request_firmware(fw, alt_path, fwctx->dev);
>> - kfree(alt_path);
>> - if (ret == 0)
>> - return ret;
>> + for (i = 0; alt_paths[i]; i++) {
>> + ret = firmware_request_nowarn(fw, alt_paths[i], fwctx->dev);
>> + if (ret == 0) {
>> + brcm_free_alt_fw_paths(alt_paths);
>> + return ret;
>> + }
>> + }
>> + brcm_free_alt_fw_paths(alt_paths);
>> }
>>
>> fallback:
>> @@ -641,6 +663,9 @@ static void brcmf_fw_request_done(const struct firmware *fw, void *ctx)
>> struct brcmf_fw *fwctx = ctx;
>> int ret;
>>
>> + brcm_free_alt_fw_paths(fwctx->alt_paths);
>> + fwctx->alt_paths = NULL;
>
> It looks suspicious that fwctx->alt_paths isn't zero'ed by other code
> paths. The brcm_free_alt_fw_paths() should take fwctx for the argument
> and fwctx->alt_paths should be set to NULL there.
There are multiple code paths for alt_paths; the initial firmware lookup
uses fwctx->alt_paths, and once we know the firmware load succeeded we
use blocking firmware requests for NVRAM/CLM/etc and those do not use
the fwctx member, but rather just keep alt_paths in function scope
(brcmf_fw_request_firmware). You're right that there was a rebase SNAFU
there though, I'll compile test each patch before sending v2. Sorry
about that. In this series the code should build again by patch #6.
Are you thinking of any particular code paths? As far as I saw when
writing this, brcmf_fw_request_done() should always get called whether
things succeed or fail. There are no other code paths that free
fwctx->alt_paths.
> On the other hand, I'd change the **alt_paths to a fixed-size array.
> This should simplify the code, making it easier to follow and maintain.
>
> - const char **alt_paths;
> + char *alt_paths[BRCM_MAX_ALT_FW_PATHS];
>
> Then you also won't need to NULL-terminate the array, which is a common
> source of bugs in kernel.
That sounds reasonable, it'll certainly make the code simpler. I'll do
that for v2.
--
Hector Martin (marcan@xxxxxxxxx)
Public Key: https://mrcn.st/pub
