# git rev-parse -q --verify 8a96efd384e6d0797a06a34503ebf21f133c74cb^{commit} 8a96efd384e6d0797a06a34503ebf21f133c74cb already have revision, skipping fetch # git checkout -q -f -B kisskb 8a96efd384e6d0797a06a34503ebf21f133c74cb # git clean -qxdf # < git log -1 # commit 8a96efd384e6d0797a06a34503ebf21f133c74cb # Author: Madhavan Srinivasan # Date: Tue Aug 27 15:46:35 2019 +0530 # # powerpc/imc: Dont create debugfs files for cpu-less nodes # # Commit <684d984038aa> ('powerpc/powernv: Add debugfs interface for # imc-mode and imc') added debugfs interface for the nest imc pmu # devices to support changing of different ucode modes. Primarily adding # this capability for debug. But when doing so, the code did not # consider the case of cpu-less nodes. So when reading the _cmd_ or # _mode_ file of a cpu-less node will create this crash. # # Faulting instruction address: 0xc0000000000d0d58 # Oops: Kernel access of bad area, sig: 11 [#1] # ... # CPU: 67 PID: 5301 Comm: cat Not tainted 5.2.0-rc6-next-20190627+ #19 # NIP: c0000000000d0d58 LR: c00000000049aa18 CTR:c0000000000d0d50 # REGS: c00020194548f9e0 TRAP: 0300 Not tainted (5.2.0-rc6-next-20190627+) # MSR: 9000000000009033 CR:28022822 XER: 00000000 # CFAR: c00000000049aa14 DAR: 000000000003fc08 DSISR:40000000 IRQMASK: 0 # ... # NIP imc_mem_get+0x8/0x20 # LR simple_attr_read+0x118/0x170 # Call Trace: # simple_attr_read+0x70/0x170 (unreliable) # debugfs_attr_read+0x6c/0xb0 # __vfs_read+0x3c/0x70 # vfs_read+0xbc/0x1a0 # ksys_read+0x7c/0x140 # system_call+0x5c/0x70 # # Patch fixes the issue with a more robust check for vbase to NULL. # # Before patch, ls output for the debugfs imc directory # # # ls /sys/kernel/debug/powerpc/imc/ # imc_cmd_0 imc_cmd_251 imc_cmd_253 imc_cmd_255 imc_mode_0 imc_mode_251 imc_mode_253 imc_mode_255 # imc_cmd_250 imc_cmd_252 imc_cmd_254 imc_cmd_8 imc_mode_250 imc_mode_252 imc_mode_254 imc_mode_8 # # After patch, ls output for the debugfs imc directory # # # ls /sys/kernel/debug/powerpc/imc/ # imc_cmd_0 imc_cmd_8 imc_mode_0 imc_mode_8 # # Actual bug here is that, we have two loops with potentially different # loop counts. That is, in imc_get_mem_addr_nest(), loop count is # obtained from the dt entries. But in case of export_imc_mode_and_cmd(), # loop was based on for_each_nid() count. Patch fixes the loop count in # latter based on the struct mem_info. Ideally it would be better to # have array size in struct imc_pmu. # # Fixes: 684d984038aa ('powerpc/powernv: Add debugfs interface for imc-mode and imc') # Reported-by: Qian Cai # Suggested-by: Michael Ellerman # Signed-off-by: Madhavan Srinivasan # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20190827101635.6942-1-maddy@linux.vnet.ibm.com # < /opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux-ld --version # < git log --format=%s --max-count=1 8a96efd384e6d0797a06a34503ebf21f133c74cb # < make -s -j 120 ARCH=m68k O=/kisskb/build/powerpc-next_m68k-defconfig_m68k CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux- defconfig # make -s -j 120 ARCH=m68k O=/kisskb/build/powerpc-next_m68k-defconfig_m68k CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/m68k-linux/bin/m68k-linux- :1511:2: warning: #warning syscall clone3 not implemented [-Wcpp] /kisskb/src/arch/m68k/mvme147/config.c: In function 'mvme147_hwclk': /kisskb/src/arch/m68k/mvme147/config.c:175:2: warning: #warning check me! [-Wcpp] /kisskb/src/arch/m68k/mvme16x/config.c: In function 'mvme16x_hwclk': /kisskb/src/arch/m68k/mvme16x/config.c:440:2: warning: #warning check me! [-Wcpp] /kisskb/src/ipc/shm.c: In function 'ksys_shmdt': /kisskb/src/ipc/shm.c:1712:59: warning: 'file' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:194:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:338:21: note: 'pdeo' was declared here /kisskb/src/lib/mpi/mpicoder.c: In function 'mpi_read_raw_from_sgl': /kisskb/src/lib/mpi/mpicoder.c:336:12: warning: 'buff' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/ocfs2/alloc.c: In function 'ocfs2_trim_mainbm': /kisskb/src/fs/ocfs2/alloc.c:7590:17: warning: 'first_bit' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/md/raid10.c: In function 'read_balance': /kisskb/src/drivers/md/raid10.c:840:22: warning: 'best_pending_slot' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/ocfs2/file.c: In function 'ocfs2_file_write_iter': /kisskb/src/fs/ocfs2/file.c:2372:3: warning: value computed is not used [-Wunused-value] /kisskb/src/drivers/net/ethernet/8390/lib8390.c:201:12: warning: '__ei_open' defined but not used [-Wunused-function] /kisskb/src/drivers/net/ethernet/8390/lib8390.c:230:12: warning: '__ei_close' defined but not used [-Wunused-function] /kisskb/src/drivers/net/ethernet/8390/lib8390.c:254:13: warning: '__ei_tx_timeout' defined but not used [-Wunused-function] /kisskb/src/drivers/net/ethernet/8390/lib8390.c:300:20: warning: '__ei_start_xmit' defined but not used [-Wunused-function] /kisskb/src/drivers/net/ethernet/8390/lib8390.c:509:13: warning: '__ei_poll' defined but not used [-Wunused-function] /kisskb/src/drivers/net/ethernet/8390/lib8390.c:850:33: warning: '__ei_get_stats' defined but not used [-Wunused-function] /kisskb/src/drivers/net/ethernet/8390/lib8390.c:950:13: warning: '__ei_set_multicast_list' defined but not used [-Wunused-function] /kisskb/src/drivers/net/ethernet/8390/lib8390.c:988:27: warning: '____alloc_ei_netdev' defined but not used [-Wunused-function] /kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char': /kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/acct.c: In function 'acct_pin_kill': /kisskb/src/kernel/acct.c:177:2: warning: value computed is not used [-Wunused-value] /kisskb/src/fs/cifs/smb2pdu.c: In function 'SMB2_ioctl_init': /kisskb/src/fs/cifs/smb2pdu.c:2671:19: warning: 'in_data_buf' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/lib/rhashtable.c: In function 'rht_deferred_worker': /kisskb/src/include/linux/rhashtable.h:110:10: warning: 'next' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/lib/rhashtable.c:222:28: note: 'next' was declared here /kisskb/src/net/core/gen_stats.c: In function '__gnet_stats_copy_basic': /kisskb/src/net/core/gen_stats.c:157:19: warning: 'seq' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/posix_acl.c: In function 'get_acl': /kisskb/src/fs/posix_acl.c:148:3: warning: value computed is not used [-Wunused-value] /kisskb/src/drivers/net/macsec.c: In function 'macsec_del_rxsa': /kisskb/src/drivers/net/macsec.c:1918:2: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/macsec.c:1918:2: warning: 'rx_sc' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/macsec.c: In function 'macsec_del_txsa': /kisskb/src/drivers/net/macsec.c:1995:2: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/macsec.c:1995:2: warning: 'tx_sc' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/macsec.c: In function 'macsec_upd_txsa': /kisskb/src/drivers/net/macsec.c:2060:5: warning: 'assoc_num' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/macsec.c:2060:24: warning: 'tx_sc' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/macsec.c:2061:21: warning: 'secy' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c: In function 'tun_get_user': /kisskb/src/drivers/net/tun.c:1831:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c:1524:31: warning: 'linear' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c:1744:46: note: 'linear' was declared here /kisskb/src/net/core/filter.c: In function 'bpf_clear_redirect_map': /kisskb/src/net/core/filter.c:3599:4: warning: value computed is not used [-Wunused-value] /kisskb/src/net/core/dev.c: In function 'validate_xmit_skb_list': /kisskb/src/net/core/dev.c:3407:15: warning: 'tail' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/sctp/output.c: In function 'sctp_packet_config': /kisskb/src/include/net/sock.h:1960:19: warning: 'sk' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/sctp/output.c:79:15: note: 'sk' was declared here Completed OK # rm -rf /kisskb/build/powerpc-next_m68k-defconfig_m68k # Build took: 0:00:43.549578