linux-kernel - Re: [linux-next:master 10251/12094] drivers/hwmon/cros_ec_hwmon.o: error: objtool: cros_ec_hwmon_read+0x6c: can't find jump dest instruction at .text+0xd2d

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Message-ID: <8aae9201-b143-4433-889f-e32664adb9f8@roeck-us.net>
Date: Sat, 7 Feb 2026 09:34:10 -0800
From: Guenter Roeck <linux@...ck-us.net>
To: Thomas Weißschuh <linux@...ssschuh.net>
Cc: kernel test robot <lkp@...el.com>, oe-kbuild-all@...ts.linux.dev,
 Tzung-Bi Shih <tzungbi@...nel.org>, linux-kernel@...r.kernel.org
Subject: Re: [linux-next:master 10251/12094] drivers/hwmon/cros_ec_hwmon.o:
 error: objtool: cros_ec_hwmon_read+0x6c: can't find jump dest instruction at
 .text+0xd2d

On 2/7/26 08:43, Thomas Weißschuh wrote:
> On 2026-02-07 08:26:37-0800, Guenter Roeck wrote:
>> On 2/7/26 07:33, Thomas Weißschuh wrote:
>>> On 2026-02-07 07:07:13-0800, Guenter Roeck wrote:
>>>> On 2/7/26 02:56, Thomas Weißschuh wrote:
>>>>> On 2026-02-07 13:14:53+0800, kernel test robot wrote:
>>>>>> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
>>>>>> head:   9845cf73f7db6094c0d8419d6adb848028f4a921
>>>>>> commit: 165c14597d53cfa7bc97b4ff8bc85f7bd98262b7 [10251/12094] hwmon: (cros_ec) Add support for temperature thresholds
>>>>>> config: x86_64-randconfig-071-20260207 (https://download.01.org/0day-ci/archive/20260207/202602071311.Q6tATiyh-lkp@intel.com/config)
>>>>>> compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
>>>>>> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260207/202602071311.Q6tATiyh-lkp@intel.com/reproduce)
>>>>>>
>>>>>> If you fix the issue in a separate patch/commit (i.e. not just a new version of
>>>>>> the same patch/commit), kindly add following tags
>>>>>> | Reported-by: kernel test robot <lkp@...el.com>
>>>>>> | Closes: https://lore.kernel.org/oe-kbuild-all/202602071311.Q6tATiyh-lkp@intel.com/
>>>>>>
>>>>>> All errors (new ones prefixed by >>):
>>>>>>
>>>>>>>> drivers/hwmon/cros_ec_hwmon.o: error: objtool: cros_ec_hwmon_read+0x6c: can't find jump dest instruction at .text+0xd2d
>>>>>
>>>>> This is due to the call to unreachable() in cros_ec_hwmon_attr_to_thres().
>>>>> Replacing it with BUG() avoids the issue.
>>>>>
>>>>> Guenter, do you want to drop the patches for now and I'll resend them
>>>>> next cycle? I can also send an incremental patch. Or you just fix it up
>>>>> in your branch.
>>>>>
>>>>
>>>> I strongly dislike BUG() because it means "I don't trust my own code".
>>>
>>> Agreed, I am not a fan either, which is why I used unreachable()
>>> originally.
>>>
>>>> The final "else" in the code is not really necessary and should be dropped.
>>>
>>> That will trigger a compiler warning:
>>>
>>> drivers/hwmon/cros_ec_hwmon.c:170:1: error: control reaches end of non-void function [-Werror=return-type]
>>>     170 | }
>>>         | ^
>>>
>>
>> I meant something like
>>
>> diff --git a/drivers/hwmon/cros_ec_hwmon.c b/drivers/hwmon/cros_ec_hwmon.c
>> index 5b998cd5e506..6cf5ab0f4b73 100644
>> --- a/drivers/hwmon/cros_ec_hwmon.c
>> +++ b/drivers/hwmon/cros_ec_hwmon.c
>> @@ -165,10 +165,7 @@ static enum ec_temp_thresholds cros_ec_hwmon_attr_to_thres(u32 attr)
>>                  return EC_TEMP_THRESH_WARN;
>>          else if (attr == hwmon_temp_crit)
>>                  return EC_TEMP_THRESH_HIGH;
>> -       else if (attr == hwmon_temp_emergency)
>> -               return EC_TEMP_THRESH_HALT;
>> -       else
>> -               unreachable();
>> +       return EC_TEMP_THRESH_HALT;     /* attr == hwmon_temp_emergency */
>>   }
> 
> Welp, that was easy :-/
> Let's use it. Feel free to apply it directly.
> 
Done - squashed into original patch.

Thanks,
Guenter