Re: [linux-next:master 6386/7300] kernel/rcu/tree.c:2965:(.text+0x5b44): relocation truncated to fit: R_CKCORE_PCREL_IMM16BY4 against `__jump_table'

["Paul E. McKenney" <paulmck@kernel.org>]

On Mon, Dec 18, 2023 at 09:42:11AM +0800, Yujie Liu wrote:
> Hi Paul,
> 
> On Thu, Dec 14, 2023 at 06:53:31AM -0800, Paul E. McKenney wrote:
> > On Thu, Dec 14, 2023 at 09:25:29AM +0800, kernel test robot wrote:
> > > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > > head:   48e8992e33abf054bcc0bb2e77b2d43bb899212e
> > > commit: 4e58aaeebb3c27993c734c99eae6881b196b1ddb [6386/7300] rcu: Restrict access to RCU CPU stall notifiers
> > > config: csky-randconfig-r013-20230826 (https://download.01.org/0day-ci/archive/20231214/202312140939.zA3tdSi2-lkp@intel.com/config)
> > > compiler: csky-linux-gcc (GCC) 13.2.0
> > > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231214/202312140939.zA3tdSi2-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@intel.com>
> > > | Closes: https://lore.kernel.org/oe-kbuild-all/202312140939.zA3tdSi2-lkp@intel.com/
> > > 
> > > All errors (new ones prefixed by >>):
> > > 
> > >    kernel/rcu/tree.o: in function `drain_page_cache':
> > > >> kernel/rcu/tree.c:2965:(.text+0x5b44): relocation truncated to fit: R_CKCORE_PCREL_IMM16BY4 against `__jump_table'
> > 
> > I have questions.  ;-)
> > 
> > Is this something that I need to fix, or is this a problem with the
> > csky toolchain?  If it is something that I need to fix, how exactly do
> > I fix it?
> 
> This seems to be a general problem with csky arch and it is not caused
> by the rcu patch. Please kindly ignore this report and we've configured
> the bot to skip it. FYI, some similar cases:
> 
> [1] https://lore.kernel.org/oe-kbuild-all/ZX0Vv3IyOi+Bp10Q@casper.infradead.org/
> [2] https://lore.kernel.org/oe-kbuild-all/202312152147.JntukftP-lkp@intel.com/
> [3] https://lore.kernel.org/oe-kbuild-all/202312160759.X3dEVpgd-lkp@intel.com/

Thank you for letting me know!

							Thanx, Paul

> Best Regards,
> Yujie
> 
> > 
> > 							Thanx, Paul
> > 
> > >    kernel/rcu/tree.c:2968:(.text+0x5b5c): relocation truncated to fit: R_CKCORE_PCREL_IMM16BY4 against `__jump_table'
> > >    kernel/rcu/tree.o: in function `kfree_rcu_shrink_scan':
> > >    kernel/rcu/tree.c:3476:(.text+0x5b6a): relocation truncated to fit: R_CKCORE_PCREL_IMM16BY4 against `__jump_table'
> > >    kernel/rcu/tree.o: in function `rcu_do_batch':
> > >    kernel/rcu/tree.c:2102:(.text+0x5be6): relocation truncated to fit: R_CKCORE_PCREL_IMM16BY4 against `__jump_table'
> > >    kernel/rcu/tree.c:2117:(.text+0x5c06): relocation truncated to fit: R_CKCORE_PCREL_IMM16BY4 against `__jump_table'
> > >    kernel/rcu/tree.c:2119:(.text+0x5c22): relocation truncated to fit: R_CKCORE_PCREL_IMM16BY4 against `__jump_table'
> > >    kernel/rcu/tree.c:2135:(.text+0x5c66): relocation truncated to fit: R_CKCORE_PCREL_IMM16BY4 against `__jump_table'
> > >    kernel/rcu/tree.c:2144:(.text+0x5ca2): relocation truncated to fit: R_CKCORE_PCREL_IMM16BY4 against `__jump_table'
> > >    kernel/rcu/tree.o: in function `rcu_lock_acquire':
> > > >> include/linux/rcupdate.h:301:(.text+0x5cb2): relocation truncated to fit: R_CKCORE_PCREL_IMM16BY4 against `__jump_table'
> > >    include/linux/rcupdate.h:301:(.text+0x5cce): relocation truncated to fit: R_CKCORE_PCREL_IMM16BY4 against `__jump_table'
> > >    kernel/rcu/tree.o: in function `rcu_lock_release':
> > >    include/linux/rcupdate.h:306:(.text+0x5cee): additional relocation overflows omitted from the output
> > > 
> > > 
> > > vim +2965 kernel/rcu/tree.c
> > > 
> > > 53c72b590b3a0a Uladzislau Rezki (Sony  2020-05-25  2951) 
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2952  static int
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2953  drain_page_cache(struct kfree_rcu_cpu *krcp)
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2954  {
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2955  	unsigned long flags;
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2956  	struct llist_node *page_list, *pos, *n;
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2957  	int freed = 0;
> > > 53c72b590b3a0a Uladzislau Rezki (Sony  2020-05-25  2958) 
> > > 6b706e5603c44f Zqiang                  2023-04-18  2959  	if (!rcu_min_cached_objs)
> > > 6b706e5603c44f Zqiang                  2023-04-18  2960  		return 0;
> > > 6b706e5603c44f Zqiang                  2023-04-18  2961  
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2962  	raw_spin_lock_irqsave(&krcp->lock, flags);
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2963  	page_list = llist_del_all(&krcp->bkvcache);
> > > ac7625ebd5f7ba Uladzislau Rezki (Sony  2021-04-15  2964) 	WRITE_ONCE(krcp->nr_bkv_objs, 0);
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15 @2965  	raw_spin_unlock_irqrestore(&krcp->lock, flags);
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2966  
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2967  	llist_for_each_safe(pos, n, page_list) {
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2968  		free_page((unsigned long)pos);
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2969  		freed++;
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2970  	}
> > > 53c72b590b3a0a Uladzislau Rezki (Sony  2020-05-25  2971) 
> > > d0bfa8b3c411e2 Zhang Qiang             2021-04-15  2972  	return freed;
> > > 53c72b590b3a0a Uladzislau Rezki (Sony  2020-05-25  2973) }
> > > 53c72b590b3a0a Uladzislau Rezki (Sony  2020-05-25  2974) 
> > > 
> > > :::::: The code at line 2965 was first introduced by commit
> > > :::::: d0bfa8b3c411e25e014e4131d2804afe29c440a6 kvfree_rcu: Release a page cache under memory pressure
> > > 
> > > :::::: TO: Zhang Qiang <qiang.zhang@windriver.com>
> > > :::::: CC: Paul E. McKenney <paulmck@kernel.org>
> > > 
> > > -- 
> > > 0-DAY CI Kernel Test Service
> > > https://github.com/intel/lkp-tests/wiki
> >