# git rev-parse -q --verify 8604895a34d92f5e186ceb931b0d1b384030ea3d^{commit} 8604895a34d92f5e186ceb931b0d1b384030ea3d already have revision, skipping fetch # git checkout -q -f -B kisskb 8604895a34d92f5e186ceb931b0d1b384030ea3d # git clean -qxdf # < git log -1 # commit 8604895a34d92f5e186ceb931b0d1b384030ea3d # Author: Michael Bringmann # Date: Thu Sep 20 11:45:13 2018 -0500 # # powerpc/pseries: Fix unitialized timer reset on migration # # After migration of a powerpc LPAR, the kernel executes code to # update the system state to reflect new platform characteristics. # # Such changes include modifications to device tree properties provided # to the system by PHYP. Property notifications received by the # post_mobility_fixup() code are passed along to the kernel in general # through a call to of_update_property() which in turn passes such # events back to all modules through entries like the '.notifier_call' # function within the NUMA module. # # When the NUMA module updates its state, it resets its event timer. If # this occurs after a previous call to stop_topology_update() or on a # system without VPHN enabled, the code runs into an unitialized timer # structure and crashes. This patch adds a safety check along this path # toward the problem code. # # An example crash log is as follows. # # ibmvscsi 30000081: Re-enabling adapter! # ------------[ cut here ]------------ # kernel BUG at kernel/time/timer.c:958! # Oops: Exception in kernel mode, sig: 5 [#1] # LE SMP NR_CPUS=2048 NUMA pSeries # Modules linked in: nfsv3 nfs_acl nfs tcp_diag udp_diag inet_diag lockd unix_diag af_packet_diag netlink_diag grace fscache sunrpc xts vmx_crypto pseries_rng sg binfmt_misc ip_tables xfs libcrc32c sd_mod ibmvscsi ibmveth scsi_transport_srp dm_mirror dm_region_hash dm_log dm_mod # CPU: 11 PID: 3067 Comm: drmgr Not tainted 4.17.0+ #179 # ... # NIP mod_timer+0x4c/0x400 # LR reset_topology_timer+0x40/0x60 # Call Trace: # 0xc0000003f9407830 (unreliable) # reset_topology_timer+0x40/0x60 # dt_update_callback+0x100/0x120 # notifier_call_chain+0x90/0x100 # __blocking_notifier_call_chain+0x60/0x90 # of_property_notify+0x90/0xd0 # of_update_property+0x104/0x150 # update_dt_property+0xdc/0x1f0 # pseries_devicetree_update+0x2d0/0x510 # post_mobility_fixup+0x7c/0xf0 # migration_store+0xa4/0xc0 # kobj_attr_store+0x30/0x60 # sysfs_kf_write+0x64/0xa0 # kernfs_fop_write+0x16c/0x240 # __vfs_write+0x40/0x200 # vfs_write+0xc8/0x240 # ksys_write+0x5c/0x100 # system_call+0x58/0x6c # # Fixes: 5d88aa85c00b ("powerpc/pseries: Update CPU maps when device tree is updated") # Cc: stable@vger.kernel.org # v3.10+ # Signed-off-by: Michael Bringmann # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux-gcc --version # < git log --format=%s --max-count=1 8604895a34d92f5e186ceb931b0d1b384030ea3d # < make -s -j 80 ARCH=mips O=/kisskb/build/powerpc-fixes_mips-defconfig_mipsel CROSS_COMPILE=/opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux- defconfig # make -s -j 80 ARCH=mips O=/kisskb/build/powerpc-fixes_mips-defconfig_mipsel CROSS_COMPILE=/opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux- FIT description: Linux 4.19.0-rc3-g8604895a34d9 Created: Mon Sep 24 22:35:02 2018 Image 0 (kernel@0) Description: Linux 4.19.0-rc3-g8604895a34d9 Created: Mon Sep 24 22:35:02 2018 Type: Kernel Image Compression: gzip compressed Data Size: 4441859 Bytes = 4337.75 KiB = 4.24 MiB Architecture: MIPS OS: Linux Load Address: 0x80100000 Entry Point: 0x8083fff0 Hash algo: sha1 Hash value: b2abed5714a3fe8c3059d3eda35fbc4f90a55d63 Image 1 (fdt@boston) Description: img,boston Device Tree Created: Mon Sep 24 22:35:02 2018 Type: Flat Device Tree Compression: uncompressed Data Size: 3668 Bytes = 3.58 KiB = 0.00 MiB Architecture: MIPS Hash algo: sha1 Hash value: 569c37cc891ce1e1f3a193cb41cc691a5d2debb5 Image 2 (fdt@ni169445) Description: NI 169445 device tree Created: Mon Sep 24 22:35:02 2018 Type: Flat Device Tree Compression: uncompressed Data Size: 1871 Bytes = 1.83 KiB = 0.00 MiB Architecture: MIPS Hash algo: sha1 Hash value: 51b89b31605ee62038c8468c429af091dfc75ec7 Image 3 (fdt@xilfpga) Description: MIPSfpga (xilfpga) Device Tree Created: Mon Sep 24 22:35:02 2018 Type: Flat Device Tree Compression: uncompressed Data Size: 2708 Bytes = 2.64 KiB = 0.00 MiB Architecture: MIPS Hash algo: sha1 Hash value: 509ce58e44c561d54539e64e9d4b47054e696fc6 Default Configuration: 'conf@default' Configuration 0 (conf@default) Description: Generic Linux kernel Kernel: kernel@0 Configuration 1 (conf@boston) Description: Boston Linux kernel Kernel: kernel@0 FDT: fdt@boston Configuration 2 (conf@ni169445) Description: NI 169445 Linux Kernel Kernel: kernel@0 FDT: fdt@ni169445 Configuration 3 (conf@xilfpga) Description: MIPSfpga Linux kernel Kernel: kernel@0 FDT: fdt@xilfpga Completed OK # rm -rf /kisskb/build/powerpc-fixes_mips-defconfig_mipsel # Build took: 0:01:50.434635