# git rev-parse -q --verify f112cb18162f4956fda5f69509e1857ce922ba58^{commit}
f112cb18162f4956fda5f69509e1857ce922ba58
already have revision, skipping fetch
# git checkout -q -f -B kisskb f112cb18162f4956fda5f69509e1857ce922ba58
# git clean -qxdf
# < git log -1
# commit f112cb18162f4956fda5f69509e1857ce922ba58
# Author: Frederic Barrat <fbarrat@linux.ibm.com>
# Date:   Wed Oct 16 18:28:33 2019 +0200
# 
#     powernv/eeh: Fix oops when probing cxl devices
#     
#     Recent cleanup in the way EEH support is added to a device causes a
#     kernel oops when the cxl driver probes a device and creates virtual
#     devices discovered on the FPGA:
#     
#         BUG: Kernel NULL pointer dereference at 0x000000a0
#         Faulting instruction address: 0xc000000000048070
#         Oops: Kernel access of bad area, sig: 7 [#1]
#         ...
#         NIP [c000000000048070] eeh_add_device_late.part.9+0x50/0x1e0
#         LR [c00000000004805c] eeh_add_device_late.part.9+0x3c/0x1e0
#         Call Trace:
#         [c000200e43983900] [c00000000079e250] _dev_info+0x5c/0x6c (unreliable)
#         [c000200e43983980] [c0000000000d1ad0] pnv_pcibios_bus_add_device+0x60/0xb0
#         [c000200e439839f0] [c0000000000606d0] pcibios_bus_add_device+0x40/0x60
#         [c000200e43983a10] [c0000000006aa3a0] pci_bus_add_device+0x30/0x100
#         [c000200e43983a80] [c0000000006aa4d4] pci_bus_add_devices+0x64/0xd0
#         [c000200e43983ac0] [c00800001c429118] cxl_pci_vphb_add+0xe0/0x130 [cxl]
#         [c000200e43983b00] [c00800001c4242ac] cxl_probe+0x504/0x5b0 [cxl]
#         [c000200e43983bb0] [c0000000006bba1c] local_pci_probe+0x6c/0x110
#         [c000200e43983c30] [c000000000159278] work_for_cpu_fn+0x38/0x60
#     
#     The root cause is that those cxl virtual devices don't have a
#     representation in the device tree and therefore no associated pci_dn
#     structure. In eeh_add_device_late(), pdn is NULL, so edev is NULL and
#     we oops.
#     
#     We never had explicit support for EEH for those virtual
#     devices. Instead, EEH events are reported to the (real) pci device and
#     handled by the cxl driver. Which can then forward to the virtual
#     devices and handle dependencies. The fact that we try adding EEH
#     support for the virtual devices is new and a side-effect of the recent
#     cleanup.
#     
#     This patch fixes it by skipping adding EEH support on powernv for
#     devices which don't have a pci_dn structure.
#     
#     The cxl driver doesn't create virtual devices on pseries so this patch
#     doesn't fix it there intentionally.
#     
#     Fixes: b905f8cdca77 ("powerpc/eeh: EEH for pSeries hot plug")
#     Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
#     Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20191016162833.22509-1-fbarrat@linux.ibm.com
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 f112cb18162f4956fda5f69509e1857ce922ba58
# < make -s -j 40 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ppc64_defconfig+NO_ALTIVEC_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  ppc64_defconfig
# Added to kconfig CONFIG_ALTIVEC=n
# Added to kconfig CONFIG_PPC_TRANSACTIONAL_MEM=n
# yes \n | make -s -j 40 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ppc64_defconfig+NO_ALTIVEC_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  oldconfig
yes: standard output: Broken pipe
# make -s -j 40 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ppc64_defconfig+NO_ALTIVEC_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
In file included from /kisskb/src/include/linux/list.h:9:0,
                 from /kisskb/src/include/linux/wait.h:7,
                 from /kisskb/src/include/linux/wait_bit.h:8,
                 from /kisskb/src/include/linux/fs.h:6,
                 from /kisskb/src/fs/btrfs/send.c:7:
/kisskb/src/fs/btrfs/send.c: In function 'process_extent':
/kisskb/src/include/linux/kernel.h:37:33: warning: 'clone_src_i_size' may be used uninitialized in this function [-Wmaybe-uninitialized]
 #define IS_ALIGNED(x, a)  (((x) & ((typeof(x))(a) - 1)) == 0)
                                 ^
/kisskb/src/fs/btrfs/send.c:5088:6: note: 'clone_src_i_size' was declared here
  u64 clone_src_i_size;
      ^
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_ppc64_defconfig+NO_ALTIVEC_powerpc-gcc5
# Build took: 0:01:46.929721