# git rev-parse -q --verify b86f6789c355a86ff6c3a8d5ab24774fd66a5a51^{commit} b86f6789c355a86ff6c3a8d5ab24774fd66a5a51 already have revision, skipping fetch # git checkout -q -f -B kisskb b86f6789c355a86ff6c3a8d5ab24774fd66a5a51 # git clean -qxdf # < git log -1 # commit b86f6789c355a86ff6c3a8d5ab24774fd66a5a51 # Author: Michael Ellerman # Date: Mon Mar 16 23:44:21 2020 +1100 # # powerpc/64: Prevent stack protection in early boot # # The previous commit reduced the amount of code that is run before we # setup a paca. However there are still a few remaining functions that # run with no paca, or worse, with an arbitrary value in r13 that will # be used as a paca pointer. # # In particular the stack protector canary is stored in the paca, so if # stack protector is activated for any of these functions we will read # the stack canary from wherever r13 points. If r13 happens to point # outside of memory we will get a machine check / checkstop. # # For example if we modify initialise_paca() to trigger stack # protection, and then boot in the mambo simulator with r13 poisoned in # skiboot before calling the kernel: # # DEBUG: 19952232: (19952232): INSTRUCTION: PC=0xC0000000191FC1E8: [0x3C4C006D]: addis r2,r12,0x6D [fetch] # DEBUG: 19952236: (19952236): INSTRUCTION: PC=0xC00000001807EAD8: [0x7D8802A6]: mflr r12 [fetch] # FATAL ERROR: 19952276: (19952276): Check Stop for 0:0: Machine Check with ME bit of MSR off # DEBUG: 19952276: (19952276): INSTRUCTION: PC=0xC0000000191FCA7C: [0xE90D0CF8]: ld r8,0xCF8(r13) [Instruction Failed] # INFO: 19952276: (19952277): ** Execution stopped: Mambo Error, Machine Check Stop, ** # systemsim % bt # pc: 0xC0000000191FCA7C initialise_paca+0x54 # lr: 0xC0000000191FC22C early_setup+0x44 # stack:0x00000000198CBED0 0x0 +0x0 # stack:0x00000000198CBF00 0xC0000000191FC22C early_setup+0x44 # stack:0x00000000198CBF90 0x1801C968 +0x1801C968 # # So annotate the relevant functions to ensure stack protection is never # enabled for them. # # Fixes: 06ec27aea9fc ("powerpc/64: add stack protector support") # Cc: stable@vger.kernel.org # v4.20+ # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20200316124421.99211-2-mpe@ellerman.id.au # < /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 b86f6789c355a86ff6c3a8d5ab24774fd66a5a51 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc44x_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- ppc44x_defconfig # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc44x_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc44x_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-next_ppc44x_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- /kisskb/src/arch/powerpc/boot/dts/virtex440-ml510.dts:335.37-439.6: Warning (pci_bridge): /plb@0/plbv46-pci@85e00000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/virtex440-ml510.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/katmai.dts:322.26-361.5: Warning (pci_bridge): /plb/pciex@d00000000: node name is not "pci" or "pcie" /kisskb/src/arch/powerpc/boot/dts/katmai.dts:363.26-402.5: Warning (pci_bridge): /plb/pciex@d20000000: node name is not "pci" or "pcie" /kisskb/src/arch/powerpc/boot/dts/katmai.dts:404.26-443.5: Warning (pci_bridge): /plb/pciex@d40000000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/katmai.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' INFO: Uncompressed kernel (size 0x5a6424) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5a6424) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5a6424) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5a6424) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5a6424) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5a6424) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5a6424) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5a6424) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5a6424) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5a6424) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x5a6424) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x595d3c) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) Image Name: Linux-5.6.0-rc2-00103-gb86f6789c Created: Thu Mar 19 00:08:27 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2901223 Bytes = 2833.23 KiB = 2.77 MiB Load Address: 00600000 Entry Point: 0060152c Image Name: Linux-5.6.0-rc2-00103-gb86f6789c Created: Thu Mar 19 00:08:28 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2868595 Bytes = 2801.36 KiB = 2.74 MiB Load Address: 00000000 Entry Point: 00000000 Image Name: Linux-5.6.0-rc2-00103-gb86f6789c Created: Thu Mar 19 00:08:28 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2900677 Bytes = 2832.69 KiB = 2.77 MiB Load Address: 00600000 Entry Point: 006001b8 Image Name: Linux-5.6.0-rc2-00103-gb86f6789c Created: Thu Mar 19 00:08:28 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2900160 Bytes = 2832.19 KiB = 2.77 MiB Load Address: 00600000 Entry Point: 00601534 Image Name: Linux-5.6.0-rc2-00103-gb86f6789c Created: Thu Mar 19 00:08:28 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2901001 Bytes = 2833.01 KiB = 2.77 MiB Load Address: 00600000 Entry Point: 00601514 Image Name: Linux-5.6.0-rc2-00103-gb86f6789c Created: Thu Mar 19 00:08:28 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2900746 Bytes = 2832.76 KiB = 2.77 MiB Load Address: 00600000 Entry Point: 00601544 Image Name: Linux-5.6.0-rc2-00103-gb86f6789c Created: Thu Mar 19 00:08:28 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2901148 Bytes = 2833.15 KiB = 2.77 MiB Load Address: 00600000 Entry Point: 006000c4 Image Name: Linux-5.6.0-rc2-00103-gb86f6789c Created: Thu Mar 19 00:08:28 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2900788 Bytes = 2832.80 KiB = 2.77 MiB Load Address: 00600000 Entry Point: 00601534 Image Name: Linux-5.6.0-rc2-00103-gb86f6789c Created: Thu Mar 19 00:08:28 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2900971 Bytes = 2832.98 KiB = 2.77 MiB Load Address: 00600000 Entry Point: 00601534 Image Name: Linux-5.6.0-rc2-00103-gb86f6789c Created: Thu Mar 19 00:08:28 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2901056 Bytes = 2833.06 KiB = 2.77 MiB Load Address: 00600000 Entry Point: 00601524 Completed OK # rm -rf /kisskb/build/powerpc-next_ppc44x_defconfig_powerpc-gcc5 # Build took: 0:00:54.513390