# git rev-parse -q --verify b3258f133d72af0bb463e198610d47ae57498b00^{commit} b3258f133d72af0bb463e198610d47ae57498b00 already have revision, skipping fetch # git checkout -q -f -B kisskb b3258f133d72af0bb463e198610d47ae57498b00 # git clean -qxdf # < git log -1 # commit b3258f133d72af0bb463e198610d47ae57498b00 # Author: Michael Ellerman # Date: Fri Mar 20 14:21:16 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/20200320032116.1024773-2-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 b3258f133d72af0bb463e198610d47ae57498b00 # < make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_powerpc-randconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- randconfig KCONFIG_SEED=0xFE59DC40 # Added to kconfig CONFIG_STANDALONE=y # Added to kconfig CONFIG_BUILD_DOCSRC=n # Added to kconfig CONFIG_MODULE_SIG=n # Added to kconfig CONFIG_CPU_BIG_ENDIAN=y # Added to kconfig CONFIG_PPC64=y # Added to kconfig CONFIG_PPC_DISABLE_WERROR=y # Added to kconfig CONFIG_SECTION_MISMATCH_WARN_ONLY=y # Added to kconfig CONFIG_PREVENT_FIRMWARE_BUILD=y # Added to kconfig CONFIG_CC_STACKPROTECTOR_STRONG=n # Added to kconfig CONFIG_GCC_PLUGINS=n # Added to kconfig CONFIG_LD_HEAD_STUB_CATCH=y # Added to kconfig CONFIG_TRIM_UNUSED_KSYMS=n # Added to kconfig CONFIG_UBSAN=n # < make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_powerpc-randconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- help # make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_powerpc-randconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- olddefconfig .config:5803:warning: override: reassigning to symbol STANDALONE .config:5805:warning: override: reassigning to symbol MODULE_SIG .config:5810:warning: override: reassigning to symbol PREVENT_FIRMWARE_BUILD .config:5813:warning: override: reassigning to symbol LD_HEAD_STUB_CATCH .config:5814:warning: override: reassigning to symbol TRIM_UNUSED_KSYMS # make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_powerpc-randconfig_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:72:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:338:21: note: 'pdeo' was declared here /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:204:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/ext4/extents.c: In function 'ext4_convert_unwritten_io_end_vec': /kisskb/src/fs/ext4/extents.c:5009:23: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/gfs2/lops.c: In function 'gfs2_find_jhead': /kisskb/src/fs/gfs2/lops.c:564:8: warning: 'off' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/block/blk-merge.c: In function 'blk_rq_map_sg': /kisskb/src/block/blk.h:79:50: warning: 'bvprv.bv_offset' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/block/blk-merge.c:486:42: note: 'bvprv.bv_offset' was declared here /kisskb/src/block/blk.h:82:12: warning: 'bvprv.bv_len' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/block/blk-merge.c:486:42: note: 'bvprv.bv_len' was declared here /kisskb/src/arch/powerpc/include/asm/io.h:799:22: warning: 'bvprv.bv_page' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/block/blk-merge.c:486:42: note: 'bvprv.bv_page' was declared here /kisskb/src/fs/f2fs/file.c: In function 'f2fs_precache_extents': /kisskb/src/fs/f2fs/file.c:3257:6: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/ocfs2/alloc.c: In function 'ocfs2_trim_mainbm': /kisskb/src/fs/ocfs2/alloc.c:7608:17: warning: 'first_bit' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/hda/hdac_regmap.c: In function 'hda_reg_write': /kisskb/src/sound/hda/hdac_regmap.c:284:16: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char': /kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/f2fs/node.c: In function '__set_nat_cache_dirty': /kisskb/src/include/linux/list.h:70:13: warning: 'head' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/f2fs/node.c:236:24: note: 'head' was declared here /kisskb/src/fs/f2fs/segment.c: In function 'f2fs_flush_sit_entries': /kisskb/src/fs/f2fs/segment.c:3929:5: warning: array subscript is below array bounds [-Warray-bounds] /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:248:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:228:19: note: 'i' was declared here /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2598:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1859:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/soc/codecs/arizona.c: In function 'arizona_hw_params': /kisskb/src/sound/soc/codecs/arizona.c:1890:3: warning: 'aif_rx_state' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/soc/codecs/arizona.c:1887:3: warning: 'aif_tx_state' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/gpu/drm/drm_dp_mst_topology.c: In function 'drm_dp_mst_dsc_aux_for_port': /kisskb/src/drivers/gpu/drm/drm_dp_mst_topology.c:5400:9: warning: missing braces around initializer [-Wmissing-braces] /kisskb/src/drivers/gpu/drm/drm_dp_mst_topology.c:5400:9: warning: (near initialization for 'desc.ident') [-Wmissing-braces] /kisskb/src/net/bridge/br_netlink.c: In function 'br_process_vlan_info': /kisskb/src/net/bridge/br_netlink.c:571:6: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/usb/core/devio.c: In function 'async_completed': /kisskb/src/drivers/usb/core/devio.c:625:23: warning: 'errno' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/soc/codecs/da7219-aad.c: In function 'da7219_aad_hptest_work': /kisskb/src/sound/soc/codecs/da7219-aad.c:317:17: warning: 'pll_ctrl' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c: In function 'sh_mobile_i2c_isr': /kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:399:26: warning: 'data' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/i2c/busses/i2c-sh_mobile.c:372:16: note: 'data' was declared here /kisskb/src/net/mac80211/mlme.c: In function 'ieee80211_rx_mgmt_beacon': /kisskb/src/net/mac80211/mlme.c:1576:3: warning: 'pwr_level_cisco' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/mac80211/mlme.c:1533:6: note: 'pwr_level_cisco' was declared here /kisskb/src/drivers/leds/leds-el15203000.c: In function 'el15203000_probe': /kisskb/src/drivers/leds/leds-el15203000.c:246:8: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/iio/temperature/mlx90632.c: In function 'mlx90632_read_raw': /kisskb/src/drivers/iio/temperature/mlx90632.c:351:37: warning: 'object_old_raw' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/iio/temperature/mlx90632.c:432:56: note: 'object_old_raw' was declared here /kisskb/src/drivers/iio/temperature/mlx90632.c:351:37: warning: 'object_new_raw' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/iio/temperature/mlx90632.c:432:40: note: 'object_new_raw' was declared here /kisskb/src/drivers/hwmon/drivetemp.c: In function 'drivetemp_get_smarttemp': /kisskb/src/drivers/hwmon/drivetemp.c:250:20: warning: 'temp_raw' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/soc/codecs/rt5665.c: In function 'rt5665_i2s_pin_event': /kisskb/src/sound/soc/codecs/rt5665.c:2663:33: warning: 'val2' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/soc/codecs/rt5665.c:2660:33: warning: 'val1' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/soc/codecs/wm8960.c: In function 'wm8960_configure_clocking': /kisskb/src/sound/soc/codecs/wm8960.c:800:70: warning: 'j' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/soc/codecs/wm8960.c:797:68: warning: 'i' may be used uninitialized in this function [-Wuninitialized] arch/powerpc/perf/perf_regs.o: In function `.perf_reg_value': perf_regs.c:(.text.perf_reg_value+0x34): undefined reference to `.is_sier_available' make[1]: *** [/kisskb/src/Makefile:1077: vmlinux] Error 1 make: *** [Makefile:179: sub-make] Error 2 Command 'make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-next-rand_powerpc-randconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- ' returned non-zero exit status 2 # rm -rf /kisskb/build/powerpc-next-rand_powerpc-randconfig_powerpc-gcc4.6 # Build took: 0:02:38.147202