linux/arch/powerpc/kernel
Nicholas Piggin f79643787e powerpc/64s: flush L1D on kernel entry
IBM Power9 processors can speculatively operate on data in the L1 cache
before it has been completely validated, via a way-prediction mechanism. It
is not possible for an attacker to determine the contents of impermissible
memory using this method, since these systems implement a combination of
hardware and software security measures to prevent scenarios where
protected data could be leaked.

However these measures don't address the scenario where an attacker induces
the operating system to speculatively execute instructions using data that
the attacker controls. This can be used for example to speculatively bypass
"kernel user access prevention" techniques, as discovered by Anthony
Steinhauser of Google's Safeside Project. This is not an attack by itself,
but there is a possibility it could be used in conjunction with
side-channels or other weaknesses in the privileged code to construct an
attack.

This issue can be mitigated by flushing the L1 cache between privilege
boundaries of concern. This patch flushes the L1 cache on kernel entry.

This is part of the fix for CVE-2020-4788.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2020-11-19 23:47:15 +11:00
..
ptrace powerpc/watchpoint/ptrace: Introduce PPC_DEBUG_FEATURE_DATA_BP_ARCH_31 2020-09-15 22:13:20 +10:00
syscalls mm/madvise: introduce process_madvise() syscall: an external memory hinting API 2020-10-18 09:27:10 -07:00
trace powerpc: Add a ppc_inst_as_str() helper 2020-07-23 17:41:36 +10:00
vdso32 Kbuild updates for v5.10 2020-10-22 13:13:57 -07:00
vdso64 Kbuild updates for v5.10 2020-10-22 13:13:57 -07:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
align.c powerpc: Use fallthrough pseudo-keyword 2020-07-29 21:09:37 +10:00
asm-offsets.c powerpc/tm: Save and restore AMR on treclaim and trechkpt 2020-10-06 23:22:25 +11:00
audit.c
btext.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
cacheinfo.c powerpc/cacheinfo: Warn if cache object chain becomes unordered 2020-07-30 22:53:48 +10:00
cacheinfo.h
compat_audit.c
cpu_setup_6xx.S powerpc/32: Blacklist functions running with MMU disabled for kprobe 2020-06-02 20:59:11 +10:00
cpu_setup_44x.S
cpu_setup_fsl_booke.S
cpu_setup_pa6t.S
cpu_setup_power.S powerpc/perf: Initialize power10 PMU registers in cpu setup routine 2020-07-26 23:34:23 +10:00
cpu_setup_ppc970.S
cputable.c powerpc/64s: Remove TM from Power10 features 2020-10-20 23:33:51 +11:00
crash_dump.c powerpc: Add prefixed instructions to instruction data type 2020-05-19 00:10:39 +10:00
dawr.c powerpc/watchpoint: Guest support for 2nd DAWR hcall 2020-07-26 23:34:19 +10:00
dbell.c powerpc: Inline doorbell sending functions 2020-07-29 21:02:09 +10:00
dma-iommu.c dma-mapping: add a new dma_alloc_pages API 2020-09-25 06:20:47 +02:00
dma-mask.c
dma-swiotlb.c
dt_cpu_ftrs.c powerpc: untangle cputable mce include 2020-10-06 23:22:22 +11:00
early_32.c
eeh.c powerpc/eeh: Fix eeh_dev_check_failure() for PE#0 2020-10-22 10:38:53 +11:00
eeh_cache.c
eeh_driver.c pci-v5.9-changes 2020-08-07 18:48:15 -07:00
eeh_event.c
eeh_pe.c powerpc/eeh: Delete eeh_pe->config_addr 2020-10-07 22:34:47 +11:00
eeh_sysfs.c powerpc/eeh: Pass eeh_dev to eeh_ops->resume_notify() 2020-07-26 23:34:20 +10:00
entry_32.S powerpc: Remove support for PowerPC 601 2020-10-08 21:17:13 +11:00
entry_64.S powerpc/security: Fix link stack flush instruction 2020-10-08 12:50:52 +11:00
epapr_hcalls.S
epapr_paravirt.c powerpc: Use a datatype for instructions 2020-05-19 00:10:37 +10:00
exceptions-64e.S powerpc/64e: remove 64s specific interrupt soft-mask code 2020-10-06 23:22:23 +11:00
exceptions-64s.S powerpc/64s: flush L1D on kernel entry 2020-11-19 23:47:15 +11:00
fadump.c powerpc updates for 5.10 2020-10-16 12:21:15 -07:00
firmware.c powerpc/pseries: Add KVM guest doorbell restrictions 2020-07-29 21:02:10 +10:00
fpu.S powerpc: Drop SYNC_601() ISYNC_601() and SYNC() 2020-10-08 21:17:13 +11:00
fsl_booke_entry_mapping.S
head_8xx.S mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
head_32.h powerpc: Drop SYNC_601() ISYNC_601() and SYNC() 2020-10-08 21:17:13 +11:00
head_40x.S powerpc: Remove SYNC on non 6xx 2020-10-08 21:17:12 +11:00
head_44x.S mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
head_64.S powerpc/64: Remove unused generic_secondary_thread_init() 2020-09-08 22:24:17 +10:00
head_book3s_32.S powerpc/32s: Remove #ifdef CONFIG_PPC_BOOK3S_32 in head_book3s_32.S 2020-10-08 21:17:15 +11:00
head_booke.h powerpc: Remove SYNC on non 6xx 2020-10-08 21:17:12 +11:00
head_fsl_booke.S mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
hw_breakpoint.c powerpc/watchpoint: Move DAWR detection logic outside of hw_breakpoint.c 2020-09-15 22:13:19 +10:00
hw_breakpoint_constraints.c powerpc/watchpoint: Move DAWR detection logic outside of hw_breakpoint.c 2020-09-15 22:13:19 +10:00
idle.c powerpc: Move arch_cpu_idle_dead() into smp.c 2020-09-18 19:59:43 +10:00
idle_6xx.S powerpc/32: Blacklist functions running with MMU disabled for kprobe 2020-06-02 20:59:11 +10:00
idle_book3e.S
idle_book3s.S
idle_e500.S powerpc/32: Blacklist functions running with MMU disabled for kprobe 2020-06-02 20:59:11 +10:00
ima_arch.c powerpc/ima: Fix secure boot rules in ima arch policy 2020-05-07 17:25:54 +10:00
io-workarounds.c mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
io.c
iomap.c iomap: constify ioreadX() iomem argument (as in generic implementation) 2020-08-14 19:56:57 -07:00
iommu.c dma-mapping: introduce dma_get_seg_boundary_nr_pages() 2020-09-03 18:12:15 +02:00
irq.c powerpc: Remove get_tb_or_rtc() 2020-10-08 21:17:14 +11:00
isa-bridge.c powerpc: remove __ioremap_at and __iounmap_at 2020-06-02 10:59:10 -07:00
jump_label.c powerpc: Use a datatype for instructions 2020-05-19 00:10:37 +10:00
kgdb.c maccess: make get_kernel_nofault() check for minimal type compatibility 2020-06-18 12:10:37 -07:00
kprobes-ftrace.c
kprobes.c powerpc: kprobes: Use generic kretprobe trampoline handler 2020-09-08 11:52:34 +02:00
kvm.c
kvm_emul.S
l2cr_6xx.S powerpc: Drop SYNC_601() ISYNC_601() and SYNC() 2020-10-08 21:17:13 +11:00
legacy_serial.c
Makefile powerpc/32s: Rename head_32.S to head_book3s_32.S 2020-10-08 21:17:14 +11:00
mce.c powerpc/mce: Avoid nmi_enter/exit in real mode on pseries hash 2020-10-16 20:13:55 +11:00
mce_power.c powerpc/powernv: Machine check handler for POWER10 2020-07-23 17:43:30 +10:00
misc.S powerpc/32: Blacklist functions running with MMU disabled for kprobe 2020-06-02 20:59:11 +10:00
misc_32.S powerpc: Rewrite FSL_BOOKE flush_cache_instruction() in C 2020-09-02 11:00:21 +10:00
misc_64.S powerpc: Remove SYNC on non 6xx 2020-10-08 21:17:12 +11:00
module.c powerpc: Use MODULES_VADDR if defined 2020-07-27 00:01:30 +10:00
module_32.c powerpc: module_[32|64].c: replace swap function with built-in one 2020-05-11 23:15:14 +10:00
module_64.c maccess: rename probe_kernel_{read,write} to copy_{from,to}_kernel_nofault 2020-06-17 10:57:41 -07:00
msi.c
note.S
nvram_64.c powerpc updates for 5.8 2020-06-05 12:39:30 -07:00
of_platform.c powerpc/eeh: Remove eeh_dev_phb_init_dynamic() 2020-07-26 23:34:19 +10:00
optprobes.c powerpc: Add ppc_inst_as_u64() 2020-05-26 23:36:57 +10:00
optprobes_head.S powerpc: Add prefixed instructions to instruction data type 2020-05-19 00:10:39 +10:00
paca.c Merge branch 'fixes' into next 2020-07-18 22:43:55 +10:00
pci-common.c Revert "powerpc/pci: unmap legacy INTx interrupts when a PHB is removed" 2020-10-15 13:42:49 +11:00
pci-hotplug.c powerpc/eeh: Release EEH device state synchronously 2020-05-18 21:58:44 +10:00
pci_32.c
pci_64.c powerpc updates for 5.8 2020-06-05 12:39:30 -07:00
pci_dn.c powerpc/eeh: Rename eeh_{add_to|remove_from}_parent_pe() 2020-07-26 23:34:21 +10:00
pci_of_scan.c
pmc.c
ppc32.h
ppc_save_regs.S powerpc: Improve ppc_save_regs() 2020-04-04 21:40:57 +11:00
proc_powerpc.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
process.c powerpc/process: Fix uninitialised variable error 2020-09-18 18:12:46 +10:00
prom.c powerpc/mm/book3s: Split radix and hash MAX_PHYSMEM limit 2020-09-15 22:13:22 +10:00
prom_init.c treewide: Convert macro and uses of __section(foo) to __section("foo") 2020-10-25 14:51:49 -07:00
prom_init_check.sh
prom_parse.c
reloc_32.S
reloc_64.S
rtas-proc.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
rtas-rtc.c
rtas.c powerpc/rtas: Restrict RTAS requests from userspace 2020-10-06 23:22:27 +11:00
rtas_flash.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
rtas_pci.c mm: reorder includes after introduction of linux/pgtable.h 2020-06-09 09:39:13 -07:00
rtasd.c powerpc/rtasd: simplify handle_rtas_event(), emit message on events 2020-07-16 13:12:38 +10:00
secure_boot.c powerpc/pseries: Detect secure and trusted boot state of the system. 2020-07-16 14:49:53 +10:00
security.c powerpc/security: Fix link stack flush instruction 2020-10-08 12:50:52 +11:00
secvar-ops.c
secvar-sysfs.c
setup-common.c powerpc: Fix P10 PVR revision in /proc/cpuinfo for SMT4 cores 2020-08-17 13:11:22 +10:00
setup.h powerpc/64: Prevent stack protection in early boot 2020-03-25 12:09:38 +11:00
setup_32.c powerpc: Remove support for PowerPC 601 2020-10-08 21:17:13 +11:00
setup_64.c powerpc/64s: flush L1D on kernel entry 2020-11-19 23:47:15 +11:00
signal.c arch-cleanup-2020-10-22 2020-10-23 10:06:38 -07:00
signal.h powerpc/64/sycall: Implement syscall entry/exit logic in C 2020-04-01 13:42:13 +11:00
signal_32.c powerpc/signal_32: Simplify loop in PPC64 save_general_regs() 2020-07-15 12:04:40 +10:00
signal_64.c powerpc/signal64: Don't opencode page prefaulting 2020-07-15 12:04:40 +10:00
smp-tbsync.c
smp.c powerpc/smp: Use GFP_ATOMIC while allocating tmp mask 2020-10-19 21:32:34 +11:00
stacktrace.c kernel: rename show_stack_loglvl() => show_stack() 2020-06-09 09:39:13 -07:00
suspend.c
swsusp.c
swsusp_32.S powerpc/32: Blacklist functions running with MMU disabled for kprobe 2020-06-02 20:59:11 +10:00
swsusp_64.c
swsusp_asm64.S
swsusp_booke.S
sys_ppc32.c
syscall_64.c Merge branch 'scv' support into next 2020-07-23 17:43:44 +10:00
syscalls.c
sysfs.c powerpc/sysfs: Remove unused 'err' variable in sysfs_create_dscr_default() 2020-09-18 20:05:24 +10:00
systbl.S powerpc/64/sycall: Implement syscall entry/exit logic in C 2020-04-01 13:42:13 +11:00
systbl_chk.sh
tau_6xx.c powerpc/tau: Disable TAU between measurements 2020-09-15 22:13:30 +10:00
time.c powerpc/time: Avoid using get_tbl() and get_tbu() internally 2020-10-08 21:17:15 +11:00
tm.S powerpc/tm: Save and restore AMR on treclaim and trechkpt 2020-10-06 23:22:25 +11:00
traps.c powerpc: Fix undetected data corruption with P9N DD2.1 VSX CI load emulation 2020-10-20 07:59:21 +11:00
ucall.S
udbg.c
udbg_16550.c
uprobes.c powerpc: Add ppc_inst_next() 2020-05-26 23:36:51 +10:00
vdso.c powerpc/vdso: Fix vdso cpu truncation 2020-07-16 13:12:47 +10:00
vecemu.c powerpc: Define and use get_user_instr() et. al. 2020-05-19 00:10:37 +10:00
vector.S powerpc: re-initialise lazy FPU/VEC counters on every fault 2020-07-16 13:00:24 +10:00
vmlinux.lds.S powerpc/64s: flush L1D on kernel entry 2020-11-19 23:47:15 +11:00
watchdog.c