Re: fs/btrfs/inode.o: warning: objtool: insert_inline_extent+0xa8: unreachable instruction

[Philip Li]

On Tue, Jul 23, 2024 at 03:07:54PM +0930, Qu Wenruo wrote:
> Hi LKP team,
> 
> Thanks a lot of your reports.
> 
> 在 2024/7/23 15:02, kernel test robot 写道:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   66ebbdfdeb093e097399b1883390079cd4c3022b
> > commit: eb1fa9ab470285d39bee268bc2a90d1786610711 btrfs: make insert_inline_extent() accept one page directly
> > date:   3 months ago
> > config: loongarch-randconfig-001-20240722 (https://download.01.org/0day-ci/archive/20240723/202407231331.vNHHJPnu-lkp@xxxxxxxxx/config)
> > compiler: loongarch64-linux-gcc (GCC) 14.1.0
> 
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240723/202407231331.vNHHJPnu-lkp@xxxxxxxxx/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@xxxxxxxxx>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202407231331.vNHHJPnu-lkp@xxxxxxxxx/
> > 
> > All warnings (new ones prefixed by >>):
> > 
> > > > fs/btrfs/inode.o: warning: objtool: insert_inline_extent+0xa8: unreachable instruction
> 
> However for those not-so-common archs, mind to provide the code line number
> if possible?
> (Better for all archs)

got it, usually the code info is provided to all archs. Not sure for this case, but
sometimes it does fail to show code info if the error like this doesn't contain line
info.

> 
> Although unreachable instruction warning is mostly false alerts, I still
> want to be sure.

Sorry, kindly ignore this report for now which could be related to tool chain upgrade to
loongarch64-linux-gcc (GCC) 14.1.0.

We will further check whether the issue can be reproduced on gcc-13.

> 
> Thanks,
> Qu
> >     fs/btrfs/inode.o: warning: objtool: btrfs_del_delalloc_inode+0xb0: unreachable instruction
> >     fs/btrfs/inode.o: warning: objtool: btrfs_set_delalloc_extent+0x18c: unreachable instruction
> >     fs/btrfs/inode.o: warning: objtool: btrfs_evict_inode+0x9c: unreachable instruction
> >     fs/btrfs/inode.o: warning: objtool: btrfs_get_extent+0x3d0: unreachable instruction
> >     fs/btrfs/inode.o: warning: objtool: btrfs_set_range_writeback+0x7c: unreachable instruction
> >     fs/btrfs/inode.o: warning: objtool: compress_file_range+0x388: unreachable instruction
> >     fs/btrfs/inode.o: warning: objtool: cow_file_range+0x128: unreachable instruction
> >     fs/btrfs/inode.o: warning: objtool: btrfs_finish_one_ordered+0x174: unreachable instruction
> >     fs/btrfs/inode.o: warning: objtool: btrfs_invalidate_folio+0x1b8: unreachable instruction
> > 
> > 
> > objdump-func vmlinux.o insert_inline_extent:
> > 
>