Re: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616

[Axel Lin <axel.lin@ingics.com>]

I can constantly hit this issue:

I trace it to mm/filemap.c: add_to_page_cache_locked
I print the in_atomic status at BEGIN and END of add_to_page_cache_locked call.
Then I got in_atomic is true at the end of add_to_page_cache_locked call.

int add_to_page_cache_locked(struct page *page, struct address_space *mapping,
                pgoff_t offset, gfp_t gfp_mask)
{
        int error;

        VM_BUG_ON(!PageLocked(page));
        VM_BUG_ON(PageSwapBacked(page));

pr_info(" ##add_to_page_cache_locked BEGIN in_atomic=%d\n", in_atomic());
        error = mem_cgroup_cache_charge(page, current->mm,
                                        gfp_mask & GFP_RECLAIM_MASK);
        if (error)
                return error;

        error = radix_tree_maybe_preload(gfp_mask & ~__GFP_HIGHMEM);
        if (error) {
                mem_cgroup_uncharge_cache_page(page);
                return error;
        }

        page_cache_get(page);
        page->mapping = mapping;
        page->index = offset;

        spin_lock_irq(&mapping->tree_lock);
        error = radix_tree_insert(&mapping->page_tree, offset, page);
        radix_tree_preload_end();
        if (unlikely(error))
                goto err_insert;
        mapping->nrpages++;
        __inc_zone_page_state(page, NR_FILE_PAGES);
        spin_unlock_irq(&mapping->tree_lock);
        trace_mm_filemap_add_to_page_cache(page);
pr_info(" ##add_to_page_cache_locked END in_atomic=%d\n", in_atomic());
        return 0;
err_insert:
        page->mapping = NULL;
        /* Leave page->index set: truncation relies upon it */
        spin_unlock_irq(&mapping->tree_lock);
        mem_cgroup_uncharge_cache_page(page);
        page_cache_release(page);
pr_info(" ##add_to_page_cache_locked ERR in_atomic=%d\n", in_atomic());
        return error;
}

Then I got below messages:
 ##add_to_page_cache_locked BEGIN in_atomic=0
 ##add_to_page_cache_locked END in_atomic=0
 ##add_to_page_cache_locked BEGIN in_atomic=0
 ##add_to_page_cache_locked END in_atomic=0
 ##add_to_page_cache_locked BEGIN in_atomic=0
 ##add_to_page_cache_locked END in_atomic=1
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616
in_atomic(): 1, irqs_disabled(): 128, pid: 1, name: swapper
1 lock held by swapper/1:
 #0:  (&sig->cred_guard_mutex){......}, at: [<00073fac>] prepare_bprm_creds+0x30/0x6c
CPU: 0 PID: 1 Comm: swapper Not tainted 3.13.0-rc2-00203-g34074bc-dirty #2022
Backtrace:
[<0000b204>] (dump_backtrace+0x0/0x108) from [<0000b398>] (show_stack+0x18/0x1c)
 r6:00000000 r5:0147abb8 r4:01c34000 r3:00200140
[<0000b380>] (show_stack+0x0/0x1c) from [<002ca948>] (dump_stack+0x20/0x28)
[<002ca928>] (dump_stack+0x0/0x28) from [<0002e3b8>] (__might_sleep+0xfc/0x11c)
[<0002e2bc>] (__might_sleep+0x0/0x11c) from [<002ce0a8>] (mutex_lock_nested+0x2c/0x30c)
 r4:0147abb8
[<002ce07c>] (mutex_lock_nested+0x0/0x30c) from [<000c4e9c>] (jffs2_readpage+0x50/0x78)
 r8:0081a654 r7:00000002 r6:01c34000 r5:0147abb8 r4:0081a640
[<000c4e4c>] (jffs2_readpage+0x0/0x78) from [<0005d854>] (__do_page_cache_readahead+0x2a0/0x338)
 r5:00000004 r4:0147ad2c
[<0005d5b4>] (__do_page_cache_readahead+0x0/0x338) from [<0005db94>] (ra_submit+0x5c/0x68)
[<0005db38>] (ra_submit+0x0/0x68) from [<0005de8c>] (ondemand_readahead+0x2ec/0x314)
 r6:00000000 r5:00000020 r4:01c0fcc8
[<0005dba0>] (ondemand_readahead+0x0/0x314) from [<0005dff8>] (page_cache_sync_readahead+0x9c/0xa8)
[<0005df5c>] (page_cache_sync_readahead+0x0/0xa8) from [<000561ec>] (generic_file_aio_read+0x314/0x7b0)
 r8:01c35eb0 r7:01c0fc40 r6:0147ad2c r5:00000000 r4:00000001
[<00055ed8>] (generic_file_aio_read+0x0/0x7b0) from [<0006e7ec>] (do_sync_read+0x88/0xd0)
[<0006e764>] (do_sync_read+0x0/0xd0) from [<0006f0e0>] (vfs_read+0xac/0xf4)
 r7:00000080 r6:01e5a400 r5:01c35ef8 r4:01c0fc40
[<0006f034>] (vfs_read+0x0/0xf4) from [<00073acc>] (kernel_read+0x24/0x2c)
 r7:000089ed r6:0147ac20 r5:01c34000 r4:01e5a400
 r7:000089ed r6:0147ac20 r5:01c34000 r4:01e5a400
[<00073aa8>] (kernel_read+0x0/0x2c) from [<00073bf8>] (prepare_binprm+0x124/0x134)
[<00073ad4>] (prepare_binprm+0x0/0x134) from [<000742c4>] (do_execve+0x250/0x528)
 r7:003599eb r6:01c34000 r5:00000000 r4:01e5a400
[<00074074>] (do_execve+0x0/0x528) from [<000083e4>] (try_to_run_init_process+0x20/0x4c)
[<000083c4>] (try_to_run_init_process+0x0/0x4c) from [<002c74f0>] (kernel_init+0x98/0x104)
 r5:002c7458 r4:003e8300
[<002c7458>] (kernel_init+0x0/0x104) from [<00009070>] (ret_from_fork+0x14/0x24)
 r4:00000000 r3:ffffffff


於 日，2013-12-01 於 18:53 +0800，Axel Lin 提到：
> Hi,
> I got below messages while booting.
> Testing on a nommu platform with 3.13.0-rc2 + patches for this SoC.
> 
> VFS: Mounted root (jffs2 filesystem) on device 31:1.
> devtmpfs: mounted
> Freeing unused kernel memory: 92K (003a4000 - 003bb000)
> BUG: sleeping function called from invalid context at kernel/locking/mutex.c:616
> in_atomic(): 1, irqs_disabled(): 128, pid: 1, name: swapper
> 1 lock held by swapper/1:
>  #0:  (&sig->cred_guard_mutex){......}, at: [<0006ea10>] prepare_bprm_creds+0x30/0x6c
> CPU: 0 PID: 1 Comm: swapper Not tainted 3.13.0-rc2-00080-g2f56e18-dirty #1987
> Backtrace: 
> [<0000b1e8>] (dump_backtrace+0x0/0x108) from [<0000b37c>] (show_stack+0x18/0x1c)
>  r6:00000000 r5:0147abb8 r4:01c38000 r3:00200140
> [<0000b364>] (show_stack+0x0/0x1c) from [<002c8f28>] (dump_stack+0x20/0x28)
> [<002c8f08>] (dump_stack+0x0/0x28) from [<0002e3dc>] (__might_sleep+0xf0/0x110)
> [<0002e2ec>] (__might_sleep+0x0/0x110) from [<002cc5ec>] (mutex_lock_nested+0x2c/0x2e4)
>  r4:0147abb8
> [<002cc5c0>] (mutex_lock_nested+0x0/0x2e4) from [<000bf9bc>] (jffs2_readpage+0x28/0x4c)
>  r8:00100100 r7:00000002 r6:00810640 r5:0147abb8 r4:00810640
> [<000bf994>] (jffs2_readpage+0x0/0x4c) from [<000584f0>] (__do_page_cache_readahead+0x1fc/0x260)
>  r5:00000004 r4:0147ad2c
> [<000582f4>] (__do_page_cache_readahead+0x0/0x260) from [<000587cc>] (ra_submit+0x2c/0x34)
> [<000587a0>] (ra_submit+0x0/0x34) from [<00058ae0>] (ondemand_readahead+0x30c/0x330)
> [<000587d4>] (ondemand_readahead+0x0/0x330) from [<00058c0c>] (page_cache_sync_readahead+0x60/0x68)
> [<00058bac>] (page_cache_sync_readahead+0x0/0x68) from [<00050f5c>] (generic_file_aio_read+0x2e0/0x768)
>  r5:00000000 r4:00000001
> [<00050c7c>] (generic_file_aio_read+0x0/0x768) from [<00069300>] (do_sync_read+0x88/0xd0)
> [<00069278>] (do_sync_read+0x0/0xd0) from [<00069b84>] (vfs_read+0xac/0xf4)
>  r7:00000080 r6:01e59200 r5:01c39ef8 r4:01c0fc40
> [<00069ad8>] (vfs_read+0x0/0xf4) from [<0006e528>] (kernel_read+0x34/0x64)
>  r7:003568ab r6:00000000 r5:01c0fc40 r4:01c39ef8
> [<0006e4f4>] (kernel_read+0x0/0x64) from [<0006e660>] (prepare_binprm+0x108/0x114)
>  r5:01c38000 r4:01e59200
> [<0006e558>] (prepare_binprm+0x0/0x114) from [<0006ed50>] (do_execve+0x278/0x560)
>  r4:01e59200
> [<0006ead8>] (do_execve+0x0/0x560) from [<000083e4>] (try_to_run_init_process+0x20/0x4c)
> [<000083c4>] (try_to_run_init_process+0x0/0x4c) from [<002c5adc>] (kernel_init+0x98/0x104)
>  r5:002c5a44 r4:003e33c0
> [<002c5a44>] (kernel_init+0x0/0x104) from [<00009070>] (ret_from_fork+0x14/0x24)
>  r4:00000000 r3:80000002
> BUG: scheduling while atomic: swapper/1/0x00000003
> 4 locks held by swapper/1:
>  #0:  (&sig->cred_guard_mutex){......}, at: [<0006ea10>] prepare_bprm_creds+0x30/0x6c
>  #1:  (&f->sem){......}, at: [<000bf9bc>] jffs2_readpage+0x28/0x4c
>  #2:  (&flash->lock){......}, at: [<00158154>] m25p80_read+0xb4/0x134
>  #3:  (lock){......}, at: [<00158b0c>] spi_write_then_read+0x38/0x158
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper Not tainted 3.13.0-rc2-00080-g2f56e18-dirty #1987
> Backtrace: 
> [<0000b1e8>] (dump_backtrace+0x0/0x108) from [<0000b37c>] (show_stack+0x18/0x1c)
>  r6:003c9ce8 r5:00000000 r4:01c30000 r3:00200140
> [<0000b364>] (show_stack+0x0/0x1c) from [<002c8f28>] (dump_stack+0x20/0x28)
> [<002c8f08>] (dump_stack+0x0/0x28) from [<002c7984>] (__schedule_bug+0x58/0x70)
> [<002c792c>] (__schedule_bug+0x0/0x70) from [<002cad30>] (__schedule+0x58/0x390)
>  r5:01c38000 r4:01c30000
> [<002cacd8>] (__schedule+0x0/0x390) from [<002cb174>] (schedule+0x88/0x8c)
> [<002cb0ec>] (schedule+0x0/0x8c) from [<002ca738>] (schedule_timeout+0x20/0x15c)
> [<002ca718>] (schedule_timeout+0x0/0x15c) from [<002cb80c>] (wait_for_common+0xe0/0x178)
>  r8:01c38000 r7:00000002 r6:01c398e4 r5:01c398e0 r4:7fffffff
> [<002cb72c>] (wait_for_common+0x0/0x178) from [<002cb8bc>] (wait_for_completion+0x18/0x1c)
> [<002cb8a4>] (wait_for_completion+0x0/0x1c) from [<00158a80>] (__spi_sync+0xbc/0xe0)
> [<001589c4>] (__spi_sync+0x0/0xe0) from [<00158ad0>] (spi_sync+0x14/0x18)
> [<00158abc>] (spi_sync+0x0/0x18) from [<00158bd4>] (spi_write_then_read+0x100/0x158)
> [<00158ad4>] (spi_write_then_read+0x0/0x158) from [<00157084>] (read_sr+0x34/0x5c)
> [<00157050>] (read_sr+0x0/0x5c) from [<00157724>] (wait_till_ready+0x24/0x70)
>  r5:ffffab54 r4:003c89d0
> [<00157700>] (wait_till_ready+0x0/0x70) from [<0015815c>] (m25p80_read+0xbc/0x134)
>  r6:01cdd814 r5:01c39ab8 r4:01cdd860 r3:01c38000
> [<001580a0>] (m25p80_read+0x0/0x134) from [<00152650>] (part_read+0x64/0xac)
> [<001525ec>] (part_read+0x0/0xac) from [<0014f814>] (mtd_read+0x90/0xc8)
>  r7:01c39c04 r6:01e26400 r4:001fe33c
> [<0014f784>] (mtd_read+0x0/0xc8) from [<000cf110>] (jffs2_flash_read+0x48/0x220)
>  r9:019b2000 r8:01e55c10 r7:00000044 r6:01c39c04 r5:00001cc4
> r4:01e56400
> [<000cf0c8>] (jffs2_flash_read+0x0/0x220) from [<000c0d8c>] (jffs2_read_dnode+0x68/0x460)
> [<000c0d24>] (jffs2_read_dnode+0x0/0x460) from [<000c1280>] (jffs2_read_inode_range+0xfc/0x15c)
> [<000c1184>] (jffs2_read_inode_range+0x0/0x15c) from [<000bf5d8>] (jffs2_do_readpage_nolock+0x70/0x100)
> [<000bf568>] (jffs2_do_readpage_nolock+0x0/0x100) from [<000bf980>] (jffs2_do_readpage_unlock+0x14/0x28)
>  r6:00810640 r5:0147abb8 r4:00810640
> [<000bf96c>] (jffs2_do_readpage_unlock+0x0/0x28) from [<000bf9cc>] (jffs2_readpage+0x38/0x4c)
>  r5:0147abb8 r4:00810640
> [<000bf994>] (jffs2_readpage+0x0/0x4c) from [<000584f0>] (__do_page_cache_readahead+0x1fc/0x260)
>  r5:00000004 r4:0147ad2c
> [<000582f4>] (__do_page_cache_readahead+0x0/0x260) from [<000587cc>] (ra_submit+0x2c/0x34)
> [<000587a0>] (ra_submit+0x0/0x34) from [<00058ae0>] (ondemand_readahead+0x30c/0x330)
> [<000587d4>] (ondemand_readahead+0x0/0x330) from [<00058c0c>] (page_cache_sync_readahead+0x60/0x68)
> [<00058bac>] (page_cache_sync_readahead+0x0/0x68) from [<00050f5c>] (generic_file_aio_read+0x2e0/0x768)
>  r5:00000000 r4:00000001
> [<00050c7c>] (generic_file_aio_read+0x0/0x768) from [<00069300>] (do_sync_read+0x88/0xd0)
> [<00069278>] (do_sync_read+0x0/0xd0) from [<00069b84>] (vfs_read+0xac/0xf4)
>  r7:00000080 r6:01e59200 r5:01c39ef8 r4:01c0fc40
> [<00069ad8>] (vfs_read+0x0/0xf4) from [<0006e528>] (kernel_read+0x34/0x64)
>  r7:003568ab r6:00000000 r5:01c0fc40 r4:01c39ef8
> [<0006e4f4>] (kernel_read+0x0/0x64) from [<0006e660>] (prepare_binprm+0x108/0x114)
>  r5:01c38000 r4:01e59200
> [<0006e558>] (prepare_binprm+0x0/0x114) from [<0006ed50>] (do_execve+0x278/0x560)
>  r4:01e59200
> [<0006ead8>] (do_execve+0x0/0x560) from [<000083e4>] (try_to_run_init_process+0x20/0x4c)
> [<000083c4>] (try_to_run_init_process+0x0/0x4c) from [<002c5adc>] (kernel_init+0x98/0x104)
>  r5:002c5a44 r4:003e33c0
> [<002c5a44>] (kernel_init+0x0/0x104) from [<00009070>] (ret_from_fork+0x14/0x24)
>  r4:00000000 r3:80000002
> BUG: scheduling while atomic: jffs2_gcd_mtd1/35/0x00000002
> 3 locks held by jffs2_gcd_mtd1/35:
>  #0:  (&c->alloc_sem){......}, at: [<000c8b88>] jffs2_garbage_collect_pass+0x24/0x794
>  #1:  (&f->sem#2){......}, at: [<000c4914>] jffs2_do_crccheck_inode+0x4c/0xa0
>  #2:  (&flash->lock){......}, at: [<00158154>] m25p80_read+0xb4/0x134
> Modules linked in:
> CPU: 0 PID: 35 Comm: jffs2_gcd_mtd1 Tainted: G        W    3.13.0-rc2-00080-g2f56e18-dirty #1987
> Backtrace: 
> [<0000b1e8>] (dump_backtrace+0x0/0x108) from [<0000b37c>] (show_stack+0x18/0x1c)
>  r6:003c9ce8 r5:00000000 r4:01cf9d80 r3:00208040
> [<0000b364>] (show_stack+0x0/0x1c) from [<002c8f28>] (dump_stack+0x20/0x28)
> [<002c8f08>] (dump_stack+0x0/0x28) from [<002c7984>] (__schedule_bug+0x58/0x70)
> [<002c792c>] (__schedule_bug+0x0/0x70) from [<002cad30>] (__schedule+0x58/0x390)
>  r5:01e72000 r4:01cf9d80
> [<002cacd8>] (__schedule+0x0/0x390) from [<002cb174>] (schedule+0x88/0x8c)
> [<002cb0ec>] (schedule+0x0/0x8c) from [<002cb314>] (schedule_preempt_disabled+0x28/0x38)
> [<002cb2ec>] (schedule_preempt_disabled+0x0/0x38) from [<002cc76c>] (mutex_lock_nested+0x1ac/0x2e4)
>  r4:01cdd814 r3:00000001
> [<002cc5c0>] (mutex_lock_nested+0x0/0x2e4) from [<00158154>] (m25p80_read+0xb4/0x134)
>  r8:00000028 r7:00000232 r6:01cdd814 r5:01e73bf8 r4:01cdd860
> [<001580a0>] (m25p80_read+0x0/0x134) from [<00152650>] (part_read+0x64/0xac)
> [<001525ec>] (part_read+0x0/0xac) from [<0014f814>] (mtd_read+0x90/0xc8)
>  r7:01e73d7c r6:01e26400 r4:0017c594
> [<0014f784>] (mtd_read+0x0/0xc8) from [<000cf110>] (jffs2_flash_read+0x48/0x220)
>  r9:00000008 r8:01e56c00 r7:00000028 r6:01e73d7c r5:01e56400
> r4:01e56400
> [<000cf0c8>] (jffs2_flash_read+0x0/0x220) from [<000c2964>] (jffs2_do_read_inode_internal+0x1b8/0x1ebc)
> [<000c27ac>] (jffs2_do_read_inode_internal+0x0/0x1ebc) from [<000c4928>] (jffs2_do_crccheck_inode+0x60/0xa0)
> [<000c48c8>] (jffs2_do_crccheck_inode+0x0/0xa0) from [<000c8cfc>] (jffs2_garbage_collect_pass+0x198/0x794)
>  r6:01c56060 r5:01e565d8 r4:01e56400
> [<000c8b64>] (jffs2_garbage_collect_pass+0x0/0x794) from [<000ca7dc>] (jffs2_garbage_collect_thread+0x138/0x170)
> [<000ca6a4>] (jffs2_garbage_collect_thread+0x0/0x170) from [<00028618>] (kthread+0xcc/0xe0)
> [<0002854c>] (kthread+0x0/0xe0) from [<00009070>] (ret_from_fork+0x14/0x24)
>  r7:00000000 r6:00000000 r5:0002854c r4:01e5e020
> BUG: scheduling while atomic: spi0/27/0x00000005
> no locks held by spi0/27.
> Modules linked in:
> CPU: 0 PID: 27 Comm: spi0 Tainted: G        W    3.13.0-rc2-00080-g2f56e18-dirty #1987
> Backtrace: 
> [<0000b1e8>] (dump_backtrace+0x0/0x108) from [<0000b37c>] (show_stack+0x18/0x1c)
>  r6:003c9ce8 r5:00000000 r4:01cf8000 r3:00208040
> [<0000b364>] (show_stack+0x0/0x1c) from [<002c8f28>] (dump_stack+0x20/0x28)
> [<002c8f08>] (dump_stack+0x0/0x28) from [<002c7984>] (__schedule_bug+0x58/0x70)
> [<002c792c>] (__schedule_bug+0x0/0x70) from [<002cad30>] (__schedule+0x58/0x390)
>  r5:01e1e000 r4:01cf8000
> [<002cacd8>] (__schedule+0x0/0x390) from [<002cb174>] (schedule+0x88/0x8c)
> [<002cb0ec>] (schedule+0x0/0x8c) from [<00028450>] (kthread_worker_fn+0xd8/0xe4)
> [<00028378>] (kthread_worker_fn+0x0/0xe4) from [<00028618>] (kthread+0xcc/0xe0)
>  r8:00000000 r7:00028378 r6:01cdd5dc r5:00000000 r4:01e19ae0
> r3:01e1e000
> [<0002854c>] (kthread+0x0/0xe0) from [<00009070>] (ret_from_fork+0x14/0x24)
>  r7:00000000 r6:00000000 r5:0002854c r4:01e19ae0
> BUG: scheduling while atomic: swapper/1/0x00000006
> 3 locks held by swapper/1:
>  #0:  (&sig->cred_guard_mutex){......}, at: [<0006ea10>] prepare_bprm_creds+0x30/0x6c
>  #1:  (&f->sem){......}, at: [<000bf9bc>] jffs2_readpage+0x28/0x4c
>  #2:  (&flash->lock){......}, at: [<00158154>] m25p80_read+0xb4/0x134
> Modules linked in:
> CPU: 0 PID: 1 Comm: swapper Tainted: G        W    3.13.0-rc2-00080-g2f56e18-dirty #1987
> Backtrace: 
> [<0000b1e8>] (dump_backtrace+0x0/0x108) from [<0000b37c>] (show_stack+0x18/0x1c)
>  r6:003c9ce8 r5:00000000 r4:01c30000 r3:00200140
> [<0000b364>] (show_stack+0x0/0x1c) from [<002c8f28>] (dump_stack+0x20/0x28)
> [<002c8f08>] (dump_stack+0x0/0x28) from [<002c7984>] (__schedule_bug+0x58/0x70)
> [<002c792c>] (__schedule_bug+0x0/0x70) from [<002cad30>] (__schedule+0x58/0x390)
>  r5:01c38000 r4:01c30000
> [<002cacd8>] (__schedule+0x0/0x390) from [<002cb174>] (schedule+0x88/0x8c)
> [<002cb0ec>] (schedule+0x0/0x8c) from [<002ca738>] (schedule_timeout+0x20/0x15c)
> [<002ca718>] (schedule_timeout+0x0/0x15c) from [<002cb80c>] (wait_for_common+0xe0/0x178)
>  r8:01c38000 r7:00000002 r6:01c399dc r5:01c399d8 r4:7fffffff
> [<002cb72c>] (wait_for_common+0x0/0x178) from [<002cb8bc>] (wait_for_completion+0x18/0x1c)
> [<002cb8a4>] (wait_for_completion+0x0/0x1c) from [<00158a80>] (__spi_sync+0xbc/0xe0)
> [<001589c4>] (__spi_sync+0x0/0xe0) from [<00158ad0>] (spi_sync+0x14/0x18)
> [<00158abc>] (spi_sync+0x0/0x18) from [<0015819c>] (m25p80_read+0xfc/0x134)
> [<001580a0>] (m25p80_read+0x0/0x134) from [<00152650>] (part_read+0x64/0xac)
> [<001525ec>] (part_read+0x0/0xac) from [<0014f814>] (mtd_read+0x90/0xc8)
>  r7:01c39c04 r6:01e26400 r4:001fe33c
> [<0014f784>] (mtd_read+0x0/0xc8) from [<000cf110>] (jffs2_flash_read+0x48/0x220)
>  r9:019b2000 r8:01e55c10 r7:00000044 r6:01c39c04 r5:00001cc4
> r4:01e56400
> [<000cf0c8>] (jffs2_flash_read+0x0/0x220) from [<000c0d8c>] (jffs2_read_dnode+0x68/0x460)
> [<000c0d24>] (jffs2_read_dnode+0x0/0x460) from [<000c1280>] (jffs2_read_inode_range+0xfc/0x15c)
> [<000c1184>] (jffs2_read_inode_range+0x0/0x15c) from [<000bf5d8>] (jffs2_do_readpage_nolock+0x70/0x100)
> [<000bf568>] (jffs2_do_readpage_nolock+0x0/0x100) from [<000bf980>] (jffs2_do_readpage_unlock+0x14/0x28)
>  r6:00810640 r5:0147abb8 r4:00810640
> [<000bf96c>] (jffs2_do_readpage_unlock+0x0/0x28) from [<000bf9cc>] (jffs2_readpage+0x38/0x4c)
>  r5:0147abb8 r4:00810640
> [<000bf994>] (jffs2_readpage+0x0/0x4c) from [<000584f0>] (__do_page_cache_readahead+0x1fc/0x260)
>  r5:00000004 r4:0147ad2c
> [<000582f4>] (__do_page_cache_readahead+0x0/0x260) from [<000587cc>] (ra_submit+0x2c/0x34)
> [<000587a0>] (ra_submit+0x0/0x34) from [<00058ae0>] (ondemand_readahead+0x30c/0x330)
> [<000587d4>] (ondemand_readahead+0x0/0x330) from [<00058c0c>] (page_cache_sync_readahead+0x60/0x68)
> [<00058bac>] (page_cache_sync_readahead+0x0/0x68) from [<00050f5c>] (generic_file_aio_read+0x2e0/0x768)
>  r5:00000000 r4:00000001
> [<00050c7c>] (generic_file_aio_read+0x0/0x768) from [<00069300>] (do_sync_read+0x88/0xd0)
> [<00069278>] (do_sync_read+0x0/0xd0) from [<00069b84>] (vfs_read+0xac/0xf4)
>  r7:00000080 r6:01e59200 r5:01c39ef8 r4:01c0fc40
> [<00069ad8>] (vfs_read+0x0/0xf4) from [<0006e528>] (kernel_read+0x34/0x64)
>  r7:003568ab r6:00000000 r5:01c0fc40 r4:01c39ef8
> [<0006e4f4>] (kernel_read+0x0/0x64) from [<0006e660>] (prepare_binprm+0x108/0x114)
>  r5:01c38000 r4:01e59200
> [<0006e558>] (prepare_binprm+0x0/0x114) from [<0006ed50>] (do_execve+0x278/0x560)
>  r4:01e59200
> [<0006ead8>] (do_execve+0x0/0x560) from [<000083e4>] (try_to_run_init_process+0x20/0x4c)
> [<000083c4>] (try_to_run_init_process+0x0/0x4c) from [<002c5adc>] (kernel_init+0x98/0x104)
>  r5:002c5a44 r4:003e33c0
> [<002c5a44>] (kernel_init+0x0/0x104) from [<00009070>] (ret_from_fork+0x14/0x24)
>  r4:00000000 r3:80000002
> BUG: scheduling while atomic: spi0/27/0x00000009
> no locks held by spi0/27.
> Modules linked in:
> CPU: 0 PID: 27 Comm: spi0 Tainted: G        W    3.13.0-rc2-00080-g2f56e18-dirty #1987
> Backtrace: 
> [<0000b1e8>] (dump_backtrace+0x0/0x108) from [<0000b37c>] (show_stack+0x18/0x1c)
>  r6:003c9ce8 r5:00000000 r4:01cf8000 r3:00208040
> [<0000b364>] (show_stack+0x0/0x1c) from [<002c8f28>] (dump_stack+0x20/0x28)
> [<002c8f08>] (dump_stack+0x0/0x28) from [<002c7984>] (__schedule_bug+0x58/0x70)
> [<002c792c>] (__schedule_bug+0x0/0x70) from [<002cad30>] (__schedule+0x58/0x390)
>  r5:01e1e000 r4:01cf8000
> [<002cacd8>] (__schedule+0x0/0x390) from [<002cb174>] (schedule+0x88/0x8c)
> [<002cb0ec>] (schedule+0x0/0x8c) from [<00028450>] (kthread_worker_fn+0xd8/0xe4)
> [<00028378>] (kthread_worker_fn+0x0/0xe4) from [<00028618>] (kthread+0xcc/0xe0)
>  r8:00000000 r7:00028378 r6:01cdd5dc r5:00000000 r4:01e19ae0
> r3:01e1e000
> [<0002854c>] (kthread+0x0/0xe0) from [<00009070>] (ret_from_fork+0x14/0x24)
>  r7:00000000 r6:00000000 r5:0002854c r4:01e19ae0
> ......
>