# git rev-parse -q --verify c790c3d2b0ec5979d83451d0688d1cd07e23d8ba^{commit} c790c3d2b0ec5979d83451d0688d1cd07e23d8ba already have revision, skipping fetch # git checkout -q -f -B kisskb c790c3d2b0ec5979d83451d0688d1cd07e23d8ba # git clean -qxdf # < git log -1 # commit c790c3d2b0ec5979d83451d0688d1cd07e23d8ba # Author: Michael Ellerman # Date: Mon May 20 20:55:20 2019 +1000 # # selftests/powerpc: Add a test of spectre_v2 mitigations # # This test uses the PMU to count branch prediction hits/misses for a # known loop, and compare the result to the reported spectre v2 # mitigation. # # This gives us a way of sanity checking that the reported mitigation is # actually in effect. # # Sample output for some cases, eg: # # Power9: # sysfs reports: 'Vulnerable' # PM_BR_PRED_CCACHE: result 368 running/enabled 5792777124 # PM_BR_MPRED_CCACHE: result 319 running/enabled 5792775546 # PM_BR_PRED_PCACHE: result 2147483281 running/enabled 5792773128 # PM_BR_MPRED_PCACHE: result 213604201 running/enabled 5792771640 # Miss percent 9 % # OK - Measured branch prediction rates match reported spectre v2 mitigation. # # sysfs reports: 'Mitigation: Indirect branch serialisation (kernel only)' # PM_BR_PRED_CCACHE: result 895 running/enabled 5780320920 # PM_BR_MPRED_CCACHE: result 822 running/enabled 5780312414 # PM_BR_PRED_PCACHE: result 2147482754 running/enabled 5780308836 # PM_BR_MPRED_PCACHE: result 213639731 running/enabled 5780307912 # Miss percent 9 % # OK - Measured branch prediction rates match reported spectre v2 mitigation. # # sysfs reports: 'Mitigation: Indirect branch cache disabled' # PM_BR_PRED_CCACHE: result 2147483649 running/enabled 20540186160 # PM_BR_MPRED_CCACHE: result 2147483649 running/enabled 20540180056 # PM_BR_PRED_PCACHE: result 0 running/enabled 20540176090 # PM_BR_MPRED_PCACHE: result 0 running/enabled 20540174182 # Miss percent 100 % # OK - Measured branch prediction rates match reported spectre v2 mitigation. # # Power8: # sysfs reports: 'Vulnerable' # PM_BR_PRED_CCACHE: result 2147483649 running/enabled 3505888142 # PM_BR_MPRED_CCACHE: result 9 running/enabled 3505882788 # Miss percent 0 % # OK - Measured branch prediction rates match reported spectre v2 mitigation. # # sysfs reports: 'Mitigation: Indirect branch cache disabled' # PM_BR_PRED_CCACHE: result 2147483649 running/enabled 16931421988 # PM_BR_MPRED_CCACHE: result 2147483649 running/enabled 16931416478 # Miss percent 100 % # OK - Measured branch prediction rates match reported spectre v2 mitigation. # success: spectre_v2 # # Signed-off-by: Michael Ellerman # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20190520105520.22274-1-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 c790c3d2b0ec5979d83451d0688d1cd07e23d8ba # < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-next_44x_akebono_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- 44x/akebono_defconfig # make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-next_44x_akebono_defconfig_powerpc-gcc4.6 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:204:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/rcu/srcutree.c: In function 'init_srcu_struct_fields': /kisskb/src/kernel/rcu/srcutree.c:140:32: warning: 'levelspread[]' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/rcu/srcutree.c:88:6: note: 'levelspread[]' was declared here /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:338:21: note: 'pdeo' was declared here /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2591:6: 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:1852:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /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/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/arch/powerpc/boot/dts/akebono.dts:251.28-289.5: Warning (pci_bridge): /plb/pciex@10100000000: node name is not "pci" or "pcie" /kisskb/src/arch/powerpc/boot/dts/akebono.dts:291.28-329.5: Warning (pci_bridge): /plb/pciex@20100000000: node name is not "pci" or "pcie" /kisskb/src/arch/powerpc/boot/dts/akebono.dts:331.28-369.5: Warning (pci_bridge): /plb/pciex@18100000000: node name is not "pci" or "pcie" /kisskb/src/arch/powerpc/boot/dts/akebono.dts:371.28-409.5: Warning (pci_bridge): /plb/pciex@28100000000: node name is not "pci" or "pcie" arch/powerpc/boot/dts/akebono.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' Completed OK # rm -rf /kisskb/build/powerpc-next_44x_akebono_defconfig_powerpc-gcc4.6 # Build took: 0:01:02.921411