# git rev-parse -q --verify 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3^{commit} 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 already have revision, skipping fetch # git checkout -q -f -B kisskb 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 # git clean -qxdf # < git log -1 # commit 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 # Author: Michael Neuling # Date: Fri Sep 14 11:14:11 2018 +1000 # # powerpc: Avoid code patching freed init sections # # This stops us from doing code patching in init sections after they've # been freed. # # In this chain: # kvm_guest_init() -> # kvm_use_magic_page() -> # fault_in_pages_readable() -> # __get_user() -> # __get_user_nocheck() -> # barrier_nospec(); # # We have a code patching location at barrier_nospec() and # kvm_guest_init() is an init function. This whole chain gets inlined, # so when we free the init section (hence kvm_guest_init()), this code # goes away and hence should no longer be patched. # # We seen this as userspace memory corruption when using a memory # checker while doing partition migration testing on powervm (this # starts the code patching post migration via # /sys/kernel/mobility/migration). In theory, it could also happen when # using /sys/kernel/debug/powerpc/barrier_nospec. # # Cc: stable@vger.kernel.org # 4.13+ # Signed-off-by: Michael Neuling # Reviewed-by: Nicholas Piggin # Reviewed-by: Christophe Leroy # Signed-off-by: Michael Ellerman # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < git log --format=%s --max-count=1 51c3c62b58b357e8d35e4cc32f7b4ec907426fe3 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ppc40x_defconfig_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- ppc40x_defconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_ppc40x_defconfig_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:185:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /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:341:21: note: 'pdeo' was declared here /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:251:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:231:19: note: 'i' was declared here /kisskb/src/drivers/i2c/i2c-core-base.c: In function 'i2c_generic_scl_recovery': /kisskb/src/drivers/i2c/i2c-core-base.c:235:5: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] INFO: Uncompressed kernel (size 0x5318c4) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5318c4) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5318c4) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x521250) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5318c4) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) Image Name: Linux-4.19.0-rc3-g51c3c62b58b3 Created: Tue Sep 18 23:39:25 2018 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2593748 Bytes = 2532.96 KiB = 2.47 MiB Load Address: 00000000 Entry Point: 00000000 Image Name: Linux-4.19.0-rc3-g51c3c62b58b3 Created: Tue Sep 18 23:39:26 2018 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2621091 Bytes = 2559.66 KiB = 2.50 MiB Load Address: 00600000 Entry Point: 00601534 Image Name: Linux-4.19.0-rc3-g51c3c62b58b3 Created: Tue Sep 18 23:39:26 2018 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2622706 Bytes = 2561.24 KiB = 2.50 MiB Load Address: 00600000 Entry Point: 00601350 Completed OK # rm -rf /kisskb/build/powerpc-fixes_ppc40x_defconfig_powerpc # Build took: 0:00:40.056723