Re: linux-next: Tree for Dec 6 (objtool, lots in btrfs)

From: Randy Dunlap
Date: Thu Dec 12 2019 - 15:25:09 EST


On 12/12/19 10:47 AM, Josh Poimboeuf wrote:
> On Wed, Dec 11, 2019 at 08:21:38AM -0800, Randy Dunlap wrote:
>> [oops, forgot to add Josh and PeterZ]
>>
>> On 12/11/19 5:49 AM, David Sterba wrote:
>>> On Fri, Dec 06, 2019 at 08:17:30AM -0800, Randy Dunlap wrote:
>>>> On 12/5/19 6:54 PM, Stephen Rothwell wrote:
>>>>> Hi all,
>>>>>
>>>>> Please do not add any material for v5.6 to your linux-next included
>>>>> trees until after v5.5-rc1 has been released.
>>>>>
>>>>> Changes since 20191204:
>>>>>
>>>>
>>>> on x86_64:
>>>>
>>>> fs/btrfs/ctree.o: warning: objtool: btrfs_search_slot()+0x2d4: unreachable instruction
>>>
>>> Can somebody enlighten me what is one supposed to do to address the
>>> warnings? Function names reported in the list contain our ASSERT macro
>>> that conditionally calls BUG() that I believe is what could cause the
>>> unreachable instructions but I don't see how.
>>>
>>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/fs/btrfs/ctree.h#n3113
>>>
>>> __cold
>>> static inline void assfail(const char *expr, const char *file, int line)
>>> {
>>> if (IS_ENABLED(CONFIG_BTRFS_ASSERT)) {
>>> pr_err("assertion failed: %s, in %s:%d\n", expr, file, line);
>>> BUG();
>>> }
>>> }
>>>
>>> #define ASSERT(expr) \
>>> (likely(expr) ? (void)0 : assfail(#expr, __FILE__, __LINE__))
>>>
>
> Randy, can you share one of the btrfs .o files? I'm not able to
> recreate.
>

Hm. I'll have to try to recreate this. I no longer have files from 20191206
(lack of space).

I'll let you know if/when I can recreate it.

--
~Randy