# git rev-parse -q --verify 2d9cdedc4bdfec9a9d484d3564a1153c3f76ae2d^{commit}
# git fetch -q -n -f git://gitlab.ozlabs.ibm.com/linuxppc/linux.git fixes-test
# git rev-parse -q --verify 2d9cdedc4bdfec9a9d484d3564a1153c3f76ae2d^{commit}
2d9cdedc4bdfec9a9d484d3564a1153c3f76ae2d
# git checkout -q -f -B kisskb 2d9cdedc4bdfec9a9d484d3564a1153c3f76ae2d
# git clean -qxdf
# < git log -1
# commit 2d9cdedc4bdfec9a9d484d3564a1153c3f76ae2d
# Author: Qian Cai <cai@redhat.com>
# Date:   Wed Oct 28 11:27:17 2020 -0400
# 
#     powerpc/eeh_cache: Fix a possible debugfs deadlock
#     
#     Lockdep complains that a possible deadlock below in
#     eeh_addr_cache_show() because it is acquiring a lock with IRQ enabled,
#     but eeh_addr_cache_insert_dev() needs to acquire the same lock with IRQ
#     disabled. Let's just make eeh_addr_cache_show() acquire the lock with
#     IRQ disabled as well.
#     
#             CPU0                    CPU1
#             ----                    ----
#        lock(&pci_io_addr_cache_root.piar_lock);
#                                     local_irq_disable();
#                                     lock(&tp->lock);
#                                     lock(&pci_io_addr_cache_root.piar_lock);
#        <Interrupt>
#          lock(&tp->lock);
#     
#       *** DEADLOCK ***
#     
#       lock_acquire+0x140/0x5f0
#       _raw_spin_lock_irqsave+0x64/0xb0
#       eeh_addr_cache_insert_dev+0x48/0x390
#       eeh_probe_device+0xb8/0x1a0
#       pnv_pcibios_bus_add_device+0x3c/0x80
#       pcibios_bus_add_device+0x118/0x290
#       pci_bus_add_device+0x28/0xe0
#       pci_bus_add_devices+0x54/0xb0
#       pcibios_init+0xc4/0x124
#       do_one_initcall+0xac/0x528
#       kernel_init_freeable+0x35c/0x3fc
#       kernel_init+0x24/0x148
#       ret_from_kernel_thread+0x5c/0x80
#     
#       lock_acquire+0x140/0x5f0
#       _raw_spin_lock+0x4c/0x70
#       eeh_addr_cache_show+0x38/0x110
#       seq_read+0x1a0/0x660
#       vfs_read+0xc8/0x1f0
#       ksys_read+0x74/0x130
#       system_call_exception+0xf8/0x1d0
#       system_call_common+0xe8/0x218
#     
#     Fixes: 5ca85ae6318d ("powerpc/eeh_cache: Add a way to dump the EEH address cache")
#     Signed-off-by: Qian Cai <cai@redhat.com>
#     Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20201028152717.8967-1-cai@redhat.com
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/m68k-linux/bin/m68k-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/m68k-linux/bin/m68k-linux-ld --version
# < git log --format=%s --max-count=1 2d9cdedc4bdfec9a9d484d3564a1153c3f76ae2d
# < make -s -j 120 ARCH=m68k O=/kisskb/build/powerpc-fixes_m68k-defconfig_m68k-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/m68k-linux/bin/m68k-linux-  defconfig
# make -s -j 120 ARCH=m68k O=/kisskb/build/powerpc-fixes_m68k-defconfig_m68k-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/m68k-linux/bin/m68k-linux-  
/kisskb/src/arch/m68k/mvme16x/config.c: In function 'mvme16x_hwclk':
/kisskb/src/arch/m68k/mvme16x/config.c:439:2: warning: #warning check me! [-Wcpp]
 #warning check me!
  ^~~~~~~
/kisskb/src/arch/m68k/mvme147/config.c: In function 'mvme147_hwclk':
/kisskb/src/arch/m68k/mvme147/config.c:174:2: warning: #warning check me! [-Wcpp]
 #warning check me!
  ^~~~~~~
In file included from /kisskb/src/kernel/rcu/update.c:578:
/kisskb/src/kernel/rcu/tasks.h:710:13: warning: 'show_rcu_tasks_rude_gp_kthread' defined but not used [-Wunused-function]
 static void show_rcu_tasks_rude_gp_kthread(void) {}
             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from /kisskb/src/include/linux/printk.h:7,
                 from /kisskb/src/include/linux/kernel.h:16,
                 from /kisskb/src/include/linux/list.h:9,
                 from /kisskb/src/include/linux/rculist.h:10,
                 from /kisskb/src/include/linux/pid.h:5,
                 from /kisskb/src/include/linux/sched.h:14,
                 from /kisskb/src/fs/btrfs/extent-tree.c:6:
/kisskb/src/fs/btrfs/extent-tree.c: In function '__btrfs_free_extent':
/kisskb/src/include/linux/kern_levels.h:5:18: warning: format '%lu' expects argument of type 'long unsigned int', but argument 8 has type 'unsigned int' [-Wformat=]
 #define KERN_SOH "\001"  /* ASCII Start Of Header */
                  ^~~~~~
/kisskb/src/include/linux/kern_levels.h:10:19: note: in expansion of macro 'KERN_SOH'
 #define KERN_CRIT KERN_SOH "2" /* critical conditions */
                   ^~~~~~~~
/kisskb/src/fs/btrfs/ctree.h:3148:24: note: in expansion of macro 'KERN_CRIT'
  btrfs_printk(fs_info, KERN_CRIT fmt, ##args)
                        ^~~~~~~~~
/kisskb/src/fs/btrfs/extent-tree.c:3187:4: note: in expansion of macro 'btrfs_crit'
    btrfs_crit(info,
    ^~~~~~~~~~
/kisskb/src/fs/btrfs/extent-tree.c:3188:83: note: format string is defined here
 "invalid extent item size for key (%llu, %u, %llu) owner %llu, has %u expect >= %lu",
                                                                                 ~~^
                                                                                 %u
In file included from /kisskb/src/arch/m68k/include/asm/atomic.h:7,
                 from /kisskb/src/include/linux/atomic.h:7,
                 from /kisskb/src/include/linux/cpumask.h:13,
                 from /kisskb/src/include/linux/smp.h:13,
                 from /kisskb/src/include/linux/lockdep.h:14,
                 from /kisskb/src/include/linux/spinlock.h:59,
                 from /kisskb/src/include/linux/wait.h:9,
                 from /kisskb/src/include/linux/wait_bit.h:8,
                 from /kisskb/src/include/linux/fs.h:6,
                 from /kisskb/src/fs/ocfs2/file.c:13:
/kisskb/src/fs/ocfs2/file.c: In function 'ocfs2_file_write_iter':
/kisskb/src/arch/m68k/include/asm/cmpxchg.h:79:22: warning: value computed is not used [-Wunused-value]
 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
                     ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/kisskb/src/fs/ocfs2/file.c:2419:3: note: in expansion of macro 'xchg'
   xchg(&iocb->ki_complete, saved_ki_complete);
   ^~~~
In file included from /kisskb/src/drivers/net/ethernet/8390/xsurf100.c:48:
/kisskb/src/drivers/net/ethernet/8390/lib8390.c:995:27: warning: '____alloc_ei_netdev' defined but not used [-Wunused-function]
 static struct net_device *____alloc_ei_netdev(int size)
                           ^~~~~~~~~~~~~~~~~~~
/kisskb/src/drivers/net/ethernet/8390/lib8390.c:957:13: warning: '__ei_set_multicast_list' defined but not used [-Wunused-function]
 static void __ei_set_multicast_list(struct net_device *dev)
             ^~~~~~~~~~~~~~~~~~~~~~~
/kisskb/src/drivers/net/ethernet/8390/lib8390.c:857:33: warning: '__ei_get_stats' defined but not used [-Wunused-function]
 static struct net_device_stats *__ei_get_stats(struct net_device *dev)
                                 ^~~~~~~~~~~~~~
/kisskb/src/drivers/net/ethernet/8390/lib8390.c:512:13: warning: '__ei_poll' defined but not used [-Wunused-function]
 static void __ei_poll(struct net_device *dev)
             ^~~~~~~~~
/kisskb/src/drivers/net/ethernet/8390/lib8390.c:303:20: warning: '__ei_start_xmit' defined but not used [-Wunused-function]
 static netdev_tx_t __ei_start_xmit(struct sk_buff *skb,
                    ^~~~~~~~~~~~~~~
/kisskb/src/drivers/net/ethernet/8390/lib8390.c:257:13: warning: '__ei_tx_timeout' defined but not used [-Wunused-function]
 static void __ei_tx_timeout(struct net_device *dev, unsigned int txqueue)
             ^~~~~~~~~~~~~~~
/kisskb/src/drivers/net/ethernet/8390/lib8390.c:233:12: warning: '__ei_close' defined but not used [-Wunused-function]
 static int __ei_close(struct net_device *dev)
            ^~~~~~~~~~
/kisskb/src/drivers/net/ethernet/8390/lib8390.c:204:12: warning: '__ei_open' defined but not used [-Wunused-function]
 static int __ei_open(struct net_device *dev)
            ^~~~~~~~~
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_m68k-defconfig_m68k-gcc8
# Build took: 0:02:31.655882