Buildresult: powerpc-fixes/corenet_basic_defconfig/powerpc-gcc4.6 built on Feb 17 2019, 20:41

kisskb

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Status:	OK
Date/Time:	Feb 17 2019, 20:41
Duration:	0:00:14.499813
Builder:	ka4
Revision:	powerpc/64s: Fix possible corruption on big endian due to pgd/pud_present() (`a58007621be33e9f7c7bed5d5ff8ecb914e1044a)`
Target:	powerpc-fixes/corenet_basic_defconfig/powerpc-gcc4.6
Branch:	powerpc-fixes
Compiler:	powerpc-gcc4.6 (powerpc-linux-gcc (GCC) 4.6.3 / GNU ld (GNU Binutils) 2.22)
Config:	corenet_basic_defconfig (download)
Log:	Download original Possible warnings (2) include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] kernel/printk/printk.c:186:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] Full Log # git rev-parse -q --verify a58007621be33e9f7c7bed5d5ff8ecb914e1044a^{commit} a58007621be33e9f7c7bed5d5ff8ecb914e1044a already have revision, skipping fetch # git checkout -q -f -B kisskb a58007621be33e9f7c7bed5d5ff8ecb914e1044a # git clean -qxdf # < git log -1 # commit a58007621be33e9f7c7bed5d5ff8ecb914e1044a # Author: Michael Ellerman <mpe@ellerman.id.au> # 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. <erhard_f@mailbox.org> # Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> # Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version # < git log --format=%s --max-count=1 a58007621be33e9f7c7bed5d5ff8ecb914e1044a # < make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_corenet_basic_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- corenet_basic_defconfig # make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_corenet_basic_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /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:339:21: note: 'pdeo' was declared here /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:186:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] Completed OK # rm -rf /kisskb/build/powerpc-fixes_corenet_basic_defconfig_powerpc-gcc4.6 # Build took: 0:00:14.499813

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