linux/arch/powerpc/kernel
Gustavo L. F. Walbon ebd3980c8d powerpc/security: Fix wrong message when RFI Flush is disable
[ Upstream commit 4e706af3cd ]

The issue was showing "Mitigation" message via sysfs whatever the
state of "RFI Flush", but it should show "Vulnerable" when it is
disabled.

If you have "L1D private" feature enabled and not "RFI Flush" you are
vulnerable to meltdown attacks.

"RFI Flush" is the key feature to mitigate the meltdown whatever the
"L1D private" state.

SEC_FTR_L1D_THREAD_PRIV is a feature for Power9 only.

So the message should be as the truth table shows:

  CPU | L1D private | RFI Flush |                sysfs
  ----|-------------|-----------|-------------------------------------
   P9 |    False    |   False   | Vulnerable
   P9 |    False    |   True    | Mitigation: RFI Flush
   P9 |    True     |   False   | Vulnerable: L1D private per thread
   P9 |    True     |   True    | Mitigation: RFI Flush, L1D private per thread
   P8 |    False    |   False   | Vulnerable
   P8 |    False    |   True    | Mitigation: RFI Flush

Output before this fix:
  # cat /sys/devices/system/cpu/vulnerabilities/meltdown
  Mitigation: RFI Flush, L1D private per thread
  # echo 0 > /sys/kernel/debug/powerpc/rfi_flush
  # cat /sys/devices/system/cpu/vulnerabilities/meltdown
  Mitigation: L1D private per thread

Output after fix:
  # cat /sys/devices/system/cpu/vulnerabilities/meltdown
  Mitigation: RFI Flush, L1D private per thread
  # echo 0 > /sys/kernel/debug/powerpc/rfi_flush
  # cat /sys/devices/system/cpu/vulnerabilities/meltdown
  Vulnerable: L1D private per thread

Signed-off-by: Gustavo L. F. Walbon <gwalbon@linux.ibm.com>
Signed-off-by: Mauro S. M. Rodrigues <maurosr@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190502210907.42375-1-gwalbon@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-01-04 19:12:56 +01:00
..
trace powerpc: consolidate -mno-sched-epilog into FTRACE flags 2019-01-13 09:51:05 +01:00
vdso32 powerpc: Fix vDSO clock_getres() 2019-12-17 20:35:40 +01:00
vdso64 powerpc: Fix vDSO clock_getres() 2019-12-17 20:35:40 +01:00
.gitignore
align.c powerpc/sstep: Introduce GETTYPE macro 2018-06-03 21:19:40 +10:00
asm-offsets.c powerpc: Fix vDSO clock_getres() 2019-12-17 20:35:40 +01:00
audit.c
btext.c powerpc: Make function btext_initialize static 2018-05-25 12:04:44 +10:00
cacheinfo.c
cacheinfo.h
compat_audit.c
cpu_setup_6xx.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
cpu_setup_44x.S
cpu_setup_fsl_booke.S powerpc: Free up CPU feature bits on 64-bit machines 2018-03-24 00:38:51 +11:00
cpu_setup_pa6t.S
cpu_setup_power.S powerpc/64s: Clear PCR on boot 2018-05-18 16:05:15 +10:00
cpu_setup_ppc970.S
cputable.c powerpc/83xx: handle machine check caused by watchdog timer 2019-12-05 09:20:47 +01:00
crash_dump.c
crash.c powerpc: remove kdump.h from page.h 2018-07-30 22:47:53 +10:00
dbell.c
dma-iommu.c
dma-swiotlb.c
dma.c PCI: Call dma_debug_add_bus() for pci_bus_type from PCI core 2018-07-30 15:58:01 -05:00
dt_cpu_ftrs.c powerpc/mm: Fixup tlbie vs mtpidr/mtlpidr ordering issue on POWER9 2019-11-10 11:27:55 +01:00
eeh_cache.c powerpc/eeh: Fix misleading comment in __eeh_addr_cache_get_device() 2018-03-27 23:44:58 +11:00
eeh_dev.c
eeh_driver.c powerpc/eeh: Fix null deref for devices removed during EEH 2019-12-01 09:16:17 +01:00
eeh_event.c powerpc/eeh: Manage EEH_PE_RECOVERING inside eeh_handle_normal_event() 2018-03-27 23:44:58 +11:00
eeh_pe.c powerpc/eeh: Fix use of EEH_PE_KEEP on wrong field 2019-12-01 09:16:18 +01:00
eeh_sysfs.c
eeh.c powerpc/eeh: Handle hugepages in ioremap space 2019-07-31 07:27:07 +02:00
entry_32.S powerpc/32: Clear on-stack exception marker upon exception return 2019-03-23 20:10:07 +01:00
entry_64.S powerpc/book3s64: Fix link stack flush on context switch 2019-12-01 09:17:46 +01:00
epapr_hcalls.S
epapr_paravirt.c
exceptions-64e.S powerpc/fsl: Fix the flush of branch predictor. 2019-04-03 06:26:20 +02:00
exceptions-64s.S powerpc: Fix HMIs on big-endian with CONFIG_RELOCATABLE=y 2019-12-05 09:20:48 +01:00
fadump.c powerpc/fadump: Do not allow hot-remove memory from fadump reserved area. 2019-02-12 19:47:16 +01:00
firmware.c
fpu.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
fsl_booke_entry_mapping.S
head_8xx.S powerpc/8xx: fix setting of pagetable for Abatron BDI debug tool. 2019-02-27 10:08:54 +01:00
head_32.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
head_40x.S powerpc/405: move PPC405_ERR77 in asm-405.h 2018-07-30 22:48:13 +10:00
head_44x.S
head_64.S powerpc/64: mark start_here_multiplatform as __ref 2019-09-16 08:21:43 +02:00
head_booke.h powerpc/fsl: Fixed warning: orphan section `__btb_flush_fixup' 2019-04-03 06:26:20 +02:00
head_fsl_booke.S powerpc/fsl: Flush the branch predictor at each kernel entry (32 bit) 2019-04-03 06:26:20 +02:00
hw_breakpoint.c perf/arch/powerpc: Implement hw_breakpoint_arch_parse() 2018-06-26 09:07:55 +02:00
idle_6xx.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
idle_book3e.S powerpc/64s: make PACA_IRQ_HARD_DIS track MSR[EE] closely 2018-07-24 22:03:14 +10:00
idle_book3s.S powerpc/powernv/idle: Restore IAMR after idle 2019-05-16 19:41:31 +02:00
idle_e500.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
idle_power4.S powerpc/64s: Fix PACA_IRQ_HARD_DIS accounting in idle_power4() 2018-08-14 15:36:02 +10:00
idle.c
ima_kexec.c
io-workarounds.c
io.c
iomap.c powerpc: iomap.c: introduce io{read|write}64_{lo_hi|hi_lo} 2018-04-05 14:59:26 +10:00
iommu.c powerpc/iommu: Avoid derefence before pointer check 2019-11-20 18:46:58 +01:00
irq.c powerpc/irq: fix stack overflow verification 2019-12-31 16:36:32 +01:00
isa-bridge.c
jump_label.c jump_label: move 'asm goto' support test to Kconfig 2019-06-04 08:02:34 +02:00
kexec_elf_64.c kernel/kexec_file.c: allow archs to set purgatory load address 2018-04-13 17:10:28 -07:00
kgdb.c
kprobes-ftrace.c bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe 2018-06-21 12:33:19 +02:00
kprobes.c bpf/error-inject/kprobes: Clear current_kprobe and enable preempt in kprobe 2018-06-21 12:33:19 +02:00
kvm_emul.S powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30 22:48:16 +10:00
kvm.c kmemleak: powerpc: skip scanning holes in the .bss section 2019-05-08 07:21:50 +02:00
l2cr_6xx.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
legacy_serial.c powerpc: Look for "stdout-path" when setting up legacy consoles 2018-12-19 19:19:52 +01:00
machine_kexec_32.c
machine_kexec_64.c powerpc/64/kexec: fix race in kexec when XIVE is shutdown 2018-05-10 23:25:08 +10:00
machine_kexec_file_64.c powerpc/kexec: Use common error handling code in setup_new_fdt() 2018-08-10 22:12:36 +10:00
machine_kexec.c powerpc: remove kdump.h from page.h 2018-07-30 22:47:53 +10:00
Makefile powerpc: Avoid clang warnings around setjmp and longjmp 2019-12-17 20:35:40 +01:00
mce_power.c powerpc/mce: Fix MCE handling for huge pages 2019-10-11 18:20:49 +02:00
mce.c powerpc/mce: Schedule work from irq_work 2019-10-11 18:20:49 +02:00
misc_32.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
misc_64.S powerpc: Allow flush_icache_range to work across ranges >4GB 2019-12-17 20:35:16 +01:00
misc.S powerpc/misc: merge reloc_offset() and add_reloc_offset() 2018-06-04 00:39:17 +10:00
module_32.c powerpc/sparse: Fix plain integer as NULL pointer warning 2018-05-25 12:04:38 +10:00
module_64.c powerpc/64/module: REL32 relocation range check 2018-11-21 09:19:08 +01:00
module.c powerpc64/module elfv1: Set opd addresses after module relocation 2018-11-13 11:08:50 -08:00
module.lds
msi.c powerpc/msi: Fix NULL pointer access in teardown code 2018-12-19 19:19:52 +01:00
nvram_64.c pstore: Convert buf_lock to semaphore 2019-06-11 12:20:52 +02:00
of_platform.c
optprobes_head.S
optprobes.c
paca.c Merge branch 'topic/paca' into next 2018-03-31 09:09:36 +11:00
pci_32.c powerpc: Remove -Wattribute-alias pragmas 2018-06-25 23:21:13 +09:00
pci_64.c powerpc: Remove -Wattribute-alias pragmas 2018-06-25 23:21:13 +09:00
pci_dn.c
pci_of_scan.c powerpc/pci/of: Fix OF flags parsing for 64bit BARs 2019-07-31 07:27:01 +02:00
pci-common.c powerpc updates for 4.19 2018-08-17 11:32:50 -07:00
pci-hotplug.c
pmc.c
ppc_save_regs.S powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30 22:48:16 +10:00
ppc32.h
proc_powerpc.c
process.c powerpc/process: Fix flush_all_to_thread for SPE 2019-12-01 09:17:01 +01:00
prom_init_check.sh powerpc/mm/radix: Update command line parsing for disable_radix 2018-04-04 16:59:50 +10:00
prom_init.c powerpc: Move path variable inside DEBUG_PROM 2018-08-10 22:12:38 +10:00
prom_parse.c
prom.c powerpc/prom: fix early DEBUG messages 2019-12-05 09:20:42 +01:00
ptrace.c powerpc/ptrace: Simplify vr_get/set() to avoid GCC warning 2019-03-23 20:10:07 +01:00
ptrace32.c
reloc_32.S
reloc_64.S
rtas_flash.c
rtas_pci.c
rtas-proc.c powerpc updates for 4.18 2018-06-07 10:23:33 -07:00
rtas-rtc.c powerpc: use time64_t in read_persistent_clock 2018-06-03 20:43:33 +10:00
rtas.c powerpc/pseries: Disable CPU hotplug across migrations 2019-11-20 18:46:59 +01:00
rtasd.c powerpc/pseries: Remove prrn_work workqueue 2019-04-20 09:16:01 +02:00
security.c powerpc/security: Fix wrong message when RFI Flush is disable 2020-01-04 19:12:56 +01:00
setup_32.c powerpc/32: Include setup.h header file to fix warnings 2018-08-10 22:12:38 +10:00
setup_64.c powerpc/speculation: Support 'mitigations=' cmdline option 2019-05-14 19:17:59 +02:00
setup-common.c powerpc/fsl: Enable runtime patching if nospectre_v2 boot arg is used 2019-04-03 06:26:20 +02:00
setup.h powerpc/tau: Synchronize function prototypes and body 2018-05-25 12:04:43 +10:00
signal_32.c powerpc/tm: Fix oops on sigreturn on systems without TM 2019-07-31 07:27:11 +02:00
signal_64.c powerpc/tm: Fix oops on sigreturn on systems without TM 2019-07-31 07:27:11 +02:00
signal.c rseq: Avoid infinite recursion when delivering SIGSEGV 2018-06-22 19:04:22 +02:00
signal.h powerpc/syscalls: signal_{32, 64} - switch to SYSCALL_DEFINE 2018-05-10 23:25:13 +10:00
smp-tbsync.c
smp.c powerpc/smp: Fix NMI IPI xmon timeout 2019-05-16 19:41:26 +02:00
stacktrace.c powerpc/64s: Fix build failures with CONFIG_NMI_IPI=n 2018-06-19 23:03:50 +10:00
suspend.c
swsusp_32.S powerpc/32s: fix suspend/resume when IBATs 4-7 are used 2019-07-26 09:14:29 +02:00
swsusp_64.c
swsusp_asm64.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
swsusp_booke.S
swsusp.c
sys_ppc32.c powerpc/syscalls: kill ppc32_select() 2018-05-10 23:25:15 +10:00
syscalls.c powerpc: Remove -Wattribute-alias pragmas 2018-06-25 23:21:13 +09:00
sysfs.c Merge branch 'topic/paca' into next 2018-03-31 09:09:36 +11:00
systbl_chk.c powerpc/syscalls: Add COMPAT_SPU_NEW() macro 2018-05-10 23:25:14 +10:00
systbl_chk.sh powerpc: Make it clearer that systbl check errors are errors 2018-05-10 23:25:16 +10:00
systbl.S powerpc/syscalls: Add COMPAT_SPU_NEW() macro 2018-05-10 23:25:14 +10:00
tau_6xx.c powerpc/tau: Make some function static 2018-05-25 12:04:44 +10:00
time.c powerpc/pseries: Mark accumulate_stolen_time() as notrace 2020-01-04 19:12:41 +01:00
tm.S powerpc/tm: Avoid possible userspace r1 corruption on reclaim 2018-09-25 22:51:32 +10:00
traps.c powerpc: dump kernel log before carrying out fadump or kdump 2019-10-07 18:57:02 +02:00
udbg_16550.c
udbg.c
uprobes.c
vdso.c powerpc: remove unneeded inclusions of cpu_has_feature.h 2018-07-30 22:47:54 +10:00
vecemu.c powerpc: Add a missing include header 2018-05-25 12:04:46 +10:00
vector.S powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30 22:48:16 +10:00
vmlinux.lds.S powerpc/fsl: Add infrastructure to fixup branch predictor flush 2019-04-03 06:26:19 +02:00
watchdog.c powerpc/watchdog: Use hrtimers for per-CPU heartbeat 2019-05-31 06:46:12 -07:00