# git rev-parse -q --verify 19ab500edb5d6020010caba48ce3b4ce4182ab63^{commit} 19ab500edb5d6020010caba48ce3b4ce4182ab63 already have revision, skipping fetch # git checkout -q -f -B kisskb 19ab500edb5d6020010caba48ce3b4ce4182ab63 # git clean -qxdf # < git log -1 # commit 19ab500edb5d6020010caba48ce3b4ce4182ab63 # Author: Aneesh Kumar K.V # Date: Sat Jun 27 12:31:46 2020 +0530 # # powerpc/mm/pkeys: Make pkey access check work on execute_only_key # # Jan reported that LTP mmap03 was getting stuck in a page fault loop # after commit c46241a370a6 ("powerpc/pkeys: Check vma before returning # key fault error to the user"), as well as a minimised reproducer: # # #include # #include # #include # #include # #include # # int main(int ac, char **av) # { # int page_sz = getpagesize(); # int fildes; # char *addr; # # fildes = open("tempfile", O_WRONLY | O_CREAT, 0666); # write(fildes, &fildes, sizeof(fildes)); # close(fildes); # # fildes = open("tempfile", O_RDONLY); # unlink("tempfile"); # # addr = mmap(0, page_sz, PROT_EXEC, MAP_FILE | MAP_PRIVATE, fildes, 0); # # printf("%d\n", *addr); # return 0; # } # # And noticed that access_pkey_error() in page fault handler now always # seem to return false: # # __do_page_fault # access_pkey_error(is_pkey: 1, is_exec: 0, is_write: 0) # arch_vma_access_permitted # pkey_access_permitted # if (!is_pkey_enabled(pkey)) # return true # return false # # pkey_access_permitted() should not check if the pkey is available in # UAMOR (using is_pkey_enabled()). The kernel needs to do that check # only when allocating keys. This also makes sure the execute_only_key # which is marked as non-manageable via UAMOR is handled correctly in # pkey_access_permitted(), and fixes the bug. # # Fixes: c46241a370a6 ("powerpc/pkeys: Check vma before returning key fault error to the user") # Reported-by: Jan Stancek # Signed-off-by: Aneesh Kumar K.V # [mpe: Include bug report details etc. in the change log] # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20200627070147.297535-1-aneesh.kumar@linux.ibm.com # < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 19ab500edb5d6020010caba48ce3b4ce4182ab63 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_85xx_tqm8555_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- 85xx/tqm8555_defconfig # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_85xx_tqm8555_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_85xx_tqm8555_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_85xx_tqm8555_defconfig_powerpc-gcc4.9 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-4.9.4-nolibc/powerpc64-linux/bin/powerpc64-linux- INFO: Uncompressed kernel (size 0x525148) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x514a4c) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) Image Name: Linux-5.8.0-rc2-g19ab500edb5d Created: Tue Jun 30 00:10:28 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2634045 Bytes = 2572.31 KiB = 2.51 MiB Load Address: 00000000 Entry Point: 00000000 Image Name: Linux-5.8.0-rc2-g19ab500edb5d Created: Tue Jun 30 00:10:28 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2664575 Bytes = 2602.12 KiB = 2.54 MiB Load Address: 00600000 Entry Point: 00600314 Completed OK # rm -rf /kisskb/build/powerpc-fixes_85xx_tqm8555_defconfig_powerpc-gcc4.9 # Build took: 0:00:50.606074