# git rev-parse -q --verify 2d9cdedc4bdfec9a9d484d3564a1153c3f76ae2d^{commit} 2d9cdedc4bdfec9a9d484d3564a1153c3f76ae2d already have revision, skipping fetch # git checkout -q -f -B kisskb 2d9cdedc4bdfec9a9d484d3564a1153c3f76ae2d # git clean -qxdf # < git log -1 # commit 2d9cdedc4bdfec9a9d484d3564a1153c3f76ae2d # Author: Qian Cai # 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); # # 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 # Reviewed-by: Oliver O'Halloran # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20201028152717.8967-1-cai@redhat.com # < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 2d9cdedc4bdfec9a9d484d3564a1153c3f76ae2d # < make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_40x_makalu_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- 40x/makalu_defconfig # < make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_40x_makalu_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_40x_makalu_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_40x_makalu_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- /kisskb/src/block/genhd.c: In function 'diskstats_show': /kisskb/src/block/genhd.c:1659:1: warning: the frame size of 1160 bytes is larger than 1024 bytes [-Wframe-larger-than=] } ^ Completed OK # rm -rf /kisskb/build/powerpc-fixes_40x_makalu_defconfig_powerpc-gcc4.9 # Build took: 0:00:46.159027