# git rev-parse -q --verify 4a1c918866022e84bc3506e7665f3f1929688ade^{commit} 4a1c918866022e84bc3506e7665f3f1929688ade already have revision, skipping fetch # git checkout -q -f -B kisskb 4a1c918866022e84bc3506e7665f3f1929688ade # git clean -qxdf # < git log -1 # commit 4a1c918866022e84bc3506e7665f3f1929688ade # 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 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 4a1c918866022e84bc3506e7665f3f1929688ade # < make -s -j 8 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ppc6xx_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- ppc6xx_defconfig # make -s -j 8 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ppc6xx_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- /kisskb/src/fs/cifs/cifssmb.c: In function '__cifs_reconnect_tcon': /kisskb/src/fs/cifs/cifssmb.c:186:1: warning: the frame size of 1328 bytes is larger than 1024 bytes [-Wframe-larger-than=] } ^ /kisskb/src/fs/cifs/smb2pdu.c: In function '__smb2_reconnect': /kisskb/src/fs/cifs/smb2pdu.c:220:1: warning: the frame size of 1328 bytes is larger than 1024 bytes [-Wframe-larger-than=] } ^ In file included from /kisskb/src/sound/ppc/pmac.h:25:0, from /kisskb/src/sound/ppc/awacs.c:29: /kisskb/src/sound/ppc/awacs.c: In function 'snd_pmac_awacs_init': /kisskb/src/include/sound/control.h:223:9: warning: 'speaker_vol' may be used uninitialized in this function [-Wmaybe-uninitialized] return _snd_ctl_add_slave(master, slave, 0); ^ /kisskb/src/sound/ppc/awacs.c:886:36: note: 'speaker_vol' was declared here struct snd_kcontrol *master_vol, *speaker_vol; ^ INFO: Uncompressed kernel (size 0xabb3a8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) INFO: Uncompressed kernel (size 0xabb3a8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) INFO: Uncompressed kernel (size 0xabb3a8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) INFO: Uncompressed kernel (size 0xabb3a8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) INFO: Uncompressed kernel (size 0xaaac90) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) INFO: Uncompressed kernel (size 0xabb3a8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) INFO: Uncompressed kernel (size 0xabb3a8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) Image Name: Linux-5.0.0-rc1+ Created: Thu Feb 14 18:44:33 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5135384 Bytes = 5015.02 KiB = 4.90 MiB Load Address: 00000000 Entry Point: 00000000 Image Name: Linux-5.0.0-rc1+ Created: Thu Feb 14 18:44:33 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5165831 Bytes = 5044.76 KiB = 4.93 MiB Load Address: 00b00000 Entry Point: 00b00894 INFO: Uncompressed kernel (size 0xabb3a8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) INFO: Uncompressed kernel (size 0xabb3a8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) Image Name: Linux-5.0.0-rc1+ Created: Thu Feb 14 18:44:33 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5165702 Bytes = 5044.63 KiB = 4.93 MiB Load Address: 00b00000 Entry Point: 00b00294 Image Name: Linux-5.0.0-rc1+ Created: Thu Feb 14 18:44:33 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5166014 Bytes = 5044.94 KiB = 4.93 MiB Load Address: 00b00000 Entry Point: 00b00894 INFO: Uncompressed kernel (size 0xabb3a8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) INFO: Uncompressed kernel (size 0xabb3a8) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) INFO: Uncompressed kernel (size 0xaaac90) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) Image Name: Linux-5.0.0-rc1+ Created: Thu Feb 14 18:44:35 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5165722 Bytes = 5044.65 KiB = 4.93 MiB Load Address: 00b00000 Entry Point: 00b00294 Image Name: Linux-5.0.0-rc1+ Created: Thu Feb 14 18:44:35 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5164637 Bytes = 5043.59 KiB = 4.93 MiB Load Address: 00b00000 Entry Point: 00b00294 Image Name: Linux-5.0.0-rc1+ Created: Thu Feb 14 18:44:35 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5165330 Bytes = 5044.27 KiB = 4.93 MiB Load Address: 00b00000 Entry Point: 00b00294 Image Name: Linux-5.0.0-rc1+ Created: Thu Feb 14 18:44:35 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5165135 Bytes = 5044.08 KiB = 4.93 MiB Load Address: 00b00000 Entry Point: 00b00294 Image Name: Linux-5.0.0-rc1+ Created: Thu Feb 14 18:44:36 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5165613 Bytes = 5044.54 KiB = 4.93 MiB Load Address: 00b00000 Entry Point: 00b00294 Completed OK # rm -rf /kisskb/build/powerpc-fixes_ppc6xx_defconfig_powerpc-gcc5 # Build took: 0:04:59.468731