linux-kernel - Re: [PATCH v10 05/10] test_firmware: add support for firmware_request

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Fri, 10 Jan 2020 20:48:53 +0100
From:   Hans de Goede <hdegoede@...hat.com>
To:     Luis Chamberlain <mcgrof@...nel.org>
Cc:     Ard Biesheuvel <ard.biesheuvel@...aro.org>,
        Darren Hart <dvhart@...radead.org>,
        Andy Shevchenko <andy@...radead.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J . Wysocki" <rafael@...nel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H . Peter Anvin" <hpa@...or.com>,
        Jonathan Corbet <corbet@....net>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Peter Jones <pjones@...hat.com>,
        Dave Olsthoorn <dave@...aar.me>, x86@...nel.org,
        platform-driver-x86@...r.kernel.org, linux-efi@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-doc@...r.kernel.org,
        linux-input@...r.kernel.org
Subject: Re: [PATCH v10 05/10] test_firmware: add support for
 firmware_request_platform

Hi,

On 1/6/20 10:33 PM, Luis Chamberlain wrote:
> On Tue, Dec 10, 2019 at 12:51:12PM +0100, Hans de Goede wrote:
>> Add support for testing firmware_request_platform through a new
>> trigger_request_platform trigger.
>>
>> Signed-off-by: Hans de Goede <hdegoede@...hat.com>
>> ---
>>   lib/test_firmware.c | 68 +++++++++++++++++++++++++++++++++++++++++++++
>>   1 file changed, 68 insertions(+)
>>
>> diff --git a/lib/test_firmware.c b/lib/test_firmware.c
>> index 251213c872b5..9af00cfc8979 100644
>> --- a/lib/test_firmware.c
>> +++ b/lib/test_firmware.c
>> @@ -24,6 +24,7 @@
>>   #include <linux/delay.h>
>>   #include <linux/kthread.h>
>>   #include <linux/vmalloc.h>
>> +#include <linux/efi_embedded_fw.h>
>>   
>>   #define TEST_FIRMWARE_NAME	"test-firmware.bin"
>>   #define TEST_FIRMWARE_NUM_REQS	4
>> @@ -507,12 +508,76 @@ static ssize_t trigger_request_store(struct device *dev,
>>   }
>>   static DEVICE_ATTR_WO(trigger_request);
>>   
>> +#ifdef CONFIG_EFI_EMBEDDED_FIRMWARE
>> +static ssize_t trigger_request_platform_store(struct device *dev,
>> +					      struct device_attribute *attr,
>> +					      const char *buf, size_t count)
>> +{
>> +	static const u8 test_data[] = {
>> +		0x55, 0xaa, 0x55, 0xaa, 0x01, 0x02, 0x03, 0x04,
>> +		0x55, 0xaa, 0x55, 0xaa, 0x05, 0x06, 0x07, 0x08,
>> +		0x55, 0xaa, 0x55, 0xaa, 0x10, 0x20, 0x30, 0x40,
>> +		0x55, 0xaa, 0x55, 0xaa, 0x50, 0x60, 0x70, 0x80
>> +	};
>> +	struct efi_embedded_fw fw;
>> +	int rc;
>> +	char *name;
>> +
>> +	name = kstrndup(buf, count, GFP_KERNEL);
>> +	if (!name)
>> +		return -ENOSPC;
>> +
>> +	pr_info("inserting test platform fw '%s'\n", name);
>> +	fw.name = name;
>> +	fw.data = (void *)test_data;
>> +	fw.length = sizeof(test_data);
>> +	list_add(&fw.list, &efi_embedded_fw_list);
>> +
>> +	pr_info("loading '%s'\n", name);
>> +
>> +	mutex_lock(&test_fw_mutex);
>> +	release_firmware(test_firmware);
>> +	test_firmware = NULL;
> 
> Seems odd to have the above two lines here before the request, why not
> after as noted below.

I modelled this after trigger_request_store which keeps the
test_firmware around after it has been called so that its contents can be
read back from the char misc device which the test_firmware module registers.

Since e.g. trigger_request_store which keeps the test_firmware around
we must check and free it before assigning a new firmware to it using
firmware_request_platform, which is why this is done before and not
after the request.

> 
>> +	rc = firmware_request_platform(&test_firmware, name, dev);
>> +	if (rc) {
>> +		pr_info("load of '%s' failed: %d\n", name, rc);
>> +		goto out;
>> +	}
>> +	if (test_firmware->size != sizeof(test_data) ||
>> +	    memcmp(test_firmware->data, test_data, sizeof(test_data)) != 0) {
>> +		pr_info("firmware contents mismatch for '%s'\n", name);
>> +		rc = -EINVAL;
>> +		goto out;
>> +	}
>> +	pr_info("loaded: %zu\n", test_firmware->size);
>> +	rc = count;
> 
> Here.
> 
>> +
>> +out:
>> +	mutex_unlock(&test_fw_mutex);
>> +
>> +	list_del(&fw.list);
>> +	kfree(name);
>> +
>> +	return rc;
>> +}
>> +static DEVICE_ATTR_WO(trigger_request_platform);
>> +#endif
>> +
>>   static DECLARE_COMPLETION(async_fw_done);
>>   
>>   static void trigger_async_request_cb(const struct firmware *fw, void *context)
>>   {
>>   	test_firmware = fw;
>>   	complete(&async_fw_done);
>> +
>> +
>> +
>> +
>> +
>> +
>> +
>> +
>> +
>>   }
> 
> Ummm, new empty lines without any code added... did you forget
> something?  Please address this.

This is a left over from an earlier version of the patch, my bad, I will remove
this and send out a new version.

Regards,

Hans