# 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 <maddy@linux.vnet.ibm.com>
# 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 <SF,HV,EE,ME,IR,DR,RI,LE>  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 <cai@lca.pw>
#     Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
#     Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20190827101635.6942-1-maddy@linux.vnet.ibm.com
# < /opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux-gcc --version
# < /opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux-ld --version
# < git log --format=%s --max-count=1 8a96efd384e6d0797a06a34503ebf21f133c74cb
# < make -s -j 120 ARCH=mips O=/kisskb/build/powerpc-next_mips-defconfig_mipsel CROSS_COMPILE=/opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux-  defconfig
# make -s -j 120 ARCH=mips O=/kisskb/build/powerpc-next_mips-defconfig_mipsel CROSS_COMPILE=/opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux-  
<stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
<stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
FIT description: Linux 5.3.0-rc2-g8a96efd384e6
Created:         Wed Sep  4 21:48:22 2019
 Image 0 (kernel@0)
  Description:  Linux 5.3.0-rc2-g8a96efd384e6
  Created:      Wed Sep  4 21:48:22 2019
  Type:         Kernel Image
  Compression:  gzip compressed
  Data Size:    4707216 Bytes = 4596.89 KiB = 4.49 MiB
  Architecture: MIPS
  OS:           Linux
  Load Address: 0x80100000
  Entry Point:  0x808ae3b0
  Hash algo:    sha1
  Hash value:   5028b1ba0747e6daccd797abb0e22f0fab8ee060
 Image 1 (fdt@boston)
  Description:  img,boston Device Tree
  Created:      Wed Sep  4 21:48:22 2019
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    3793 Bytes = 3.70 KiB = 0.00 MiB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   4799f50d688573234da6e9d7701234d394759ef4
 Image 2 (fdt@ni169445)
  Description:  NI 169445 device tree
  Created:      Wed Sep  4 21:48:22 2019
  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@ocelot_pcb123)
  Description:  MSCC Ocelot PCB123 Device Tree
  Created:      Wed Sep  4 21:48:22 2019
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    4615 Bytes = 4.51 KiB = 0.00 MiB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   8754eadee600cac22c9c34884cd901aac7e95e8a
 Image 4 (fdt@ocelot_pcb120)
  Description:  MSCC Ocelot PCB120 Device Tree
  Created:      Wed Sep  4 21:48:22 2019
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    5174 Bytes = 5.05 KiB = 0.00 MiB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   1ab7d0871c0a9345c6269fb491bf028224da8256
 Image 5 (fdt@xilfpga)
  Description:  MIPSfpga (xilfpga) Device Tree
  Created:      Wed Sep  4 21:48:22 2019
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    2708 Bytes = 2.64 KiB = 0.00 MiB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   63d058b780f65e22da30f0a183433765f1807f1d
 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@ocelot_pcb123)
  Description:  Ocelot Linux kernel
  Kernel:       kernel@0
  FDT:          fdt@ocelot_pcb123
 Configuration 4 (conf@ocelot_pcb120)
  Description:  Ocelot Linux kernel
  Kernel:       kernel@0
  FDT:          fdt@ocelot_pcb120
 Configuration 5 (conf@xilfpga)
  Description:  MIPSfpga Linux kernel
  Kernel:       kernel@0
  FDT:          fdt@xilfpga
Completed OK
# rm -rf /kisskb/build/powerpc-next_mips-defconfig_mipsel
# Build took: 0:01:03.118261