# git rev-parse -q --verify d9da4b51c27d706592a967c45c8525ed4e19bc6a^{commit} d9da4b51c27d706592a967c45c8525ed4e19bc6a already have revision, skipping fetch # git checkout -q -f -B kisskb d9da4b51c27d706592a967c45c8525ed4e19bc6a # git clean -qxdf # < git log -1 # commit d9da4b51c27d706592a967c45c8525ed4e19bc6a # Author: Michael Ellerman # Date: Thu Feb 14 15:00:36 2019 +1100 # # powerpc/64s: Fix possible corruption on big endian due to pgd/pud_present() # # In v4.20 we changed our pgd/pud_present() to check for _PAGE_PRESENT # rather than just checking that the value is non-zero, e.g.: # # static inline int pgd_present(pgd_t pgd) # { # - return !pgd_none(pgd); # + return (pgd_raw(pgd) & cpu_to_be64(_PAGE_PRESENT)); # } # # Unfortunately this is broken on big endian, as the result of the # bitwise && is truncated to int, which is always zero because # _PAGE_PRESENT is 0x8000000000000000ul. This means pgd_present() and # pud_present() are always false at compile time, and the compiler # elides the subsequent code. # # Remarkably with that bug present we are still able to boot and run # with few noticeable effects. However under some work loads we are able # to trigger a warning in the ext4 code: # # WARNING: CPU: 11 PID: 29593 at fs/ext4/inode.c:3927 .ext4_set_page_dirty+0x70/0xb0 # CPU: 11 PID: 29593 Comm: debugedit Not tainted 4.20.0-rc1 #1 # ... # NIP .ext4_set_page_dirty+0x70/0xb0 # LR .set_page_dirty+0xa0/0x150 # Call Trace: # .set_page_dirty+0xa0/0x150 # .unmap_page_range+0xbf0/0xe10 # .unmap_vmas+0x84/0x130 # .unmap_region+0xe8/0x190 # .__do_munmap+0x2f0/0x510 # .__vm_munmap+0x80/0x110 # .__se_sys_munmap+0x14/0x30 # system_call+0x5c/0x70 # # The fix is simple, we need to convert the result of the bitwise && to # an int before returning it. # # Thanks to Erhard, Jan Kara and Aneesh for help with debugging. # # Fixes: da7ad366b497 ("powerpc/mm/book3s: Update pmd_present to look at _PAGE_PRESENT bit") # Cc: stable@vger.kernel.org # v4.20+ # Reported-by: Erhard F. # Reviewed-by: Aneesh Kumar K.V # Signed-off-by: Michael Ellerman # < /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 d9da4b51c27d706592a967c45c8525ed4e19bc6a # < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc85xx_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- mpc85xx_defconfig # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc85xx_defconfig_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/kernel.h:10:0, from /kisskb/src/include/linux/list.h:9, from /kisskb/src/include/linux/module.h:9, from /kisskb/src/drivers/net/ethernet/freescale/fs_enet/mac-scc.c:15: /kisskb/src/drivers/net/ethernet/freescale/fs_enet/mac-scc.c: In function 'allocate_bd': /kisskb/src/include/linux/err.h:22:49: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast] #define IS_ERR_VALUE(x) unlikely((unsigned long)(void *)(x) >= (unsigned long)-MAX_ERRNO) ^ /kisskb/src/include/linux/compiler.h:77:42: note: in definition of macro 'unlikely' # define unlikely(x) __builtin_expect(!!(x), 0) ^ /kisskb/src/drivers/net/ethernet/freescale/fs_enet/mac-scc.c:139:6: note: in expansion of macro 'IS_ERR_VALUE' if (IS_ERR_VALUE(fep->ring_mem_addr)) ^ /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8541cds.dts:334.3-21: Warning (pci_device_bus_num): /pci@e0008000/i8259@19000:bus-range: PCI bus number 1 out of range, expected (0 - 0) /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8555cds.dts:334.3-21: Warning (pci_device_bus_num): /pci@e0008000/i8259@19000:bus-range: PCI bus number 1 out of range, expected (0 - 0) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb99638) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) INFO: Uncompressed kernel (size 0xb88e04) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xc00000) Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5723239 Bytes = 5589.10 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c002a4 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5723170 Bytes = 5589.03 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c002a4 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5723405 Bytes = 5589.26 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c002a4 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5722979 Bytes = 5588.85 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c002a4 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5722981 Bytes = 5588.85 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c002a4 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5724563 Bytes = 5590.39 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c002a4 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5723209 Bytes = 5589.07 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c00314 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5723072 Bytes = 5588.94 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c00314 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5723746 Bytes = 5589.60 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c002a4 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5723196 Bytes = 5589.06 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c00314 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5725108 Bytes = 5590.93 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c002a4 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5724481 Bytes = 5590.31 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c002a4 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5723176 Bytes = 5589.04 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c00314 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5693009 Bytes = 5559.58 KiB = 5.43 MiB Load Address: 00000000 Entry Point: 00000000 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5723195 Bytes = 5589.06 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c002a4 Image Name: Linux-5.0.0-rc1-gd9da4b51c27d Created: Sat Feb 16 22:06:32 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5723177 Bytes = 5589.04 KiB = 5.46 MiB Load Address: 00c00000 Entry Point: 00c00314 Completed OK # rm -rf /kisskb/build/powerpc-fixes_mpc85xx_defconfig_powerpc-gcc5 # Build took: 0:01:10.811183