linux/arch/powerpc/kernel
Daniel Axtens d4a8e98621 powerpc/64: Setup a paca before parsing device tree etc.
Currently we set up the paca after parsing the device tree for CPU
features. Prior to that, r13 contains random data, which means there
is random data in r13 while we're running the generic dt parsing code.

This random data varies depending on whether we boot through a vmlinux
or a zImage: for the vmlinux case it's usually around zero, but for
zImages we see random values like 912a72603d420015.

This is poor practice, and can also lead to difficult-to-debug
crashes. For example, when kcov is enabled, the kcov instrumentation
attempts to read preempt_count out of the current task, which goes via
the paca. This then crashes in the zImage case.

Similarly stack protector can cause crashes if r13 is bogus, by
reading from the stack canary in the paca.

To resolve this:

 - move the paca setup to before the CPU feature parsing.

 - because we no longer have access to CPU feature flags in paca
 setup, change the HV feature test in the paca setup path to consider
 the actual value of the MSR rather than the CPU feature.

Translations get switched on once we leave early_setup, so I think
we'd already catch any other cases where the paca or task aren't set
up.

Boot tested on a P9 guest and host.

Fixes: fb0b0a73b2 ("powerpc: Enable kcov")
Fixes: 06ec27aea9 ("powerpc/64: add stack protector support")
Cc: stable@vger.kernel.org # v4.20+
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Daniel Axtens <dja@axtens.net>
[mpe: Reword comments & change log a bit to mention stack protector]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320032116.1024773-1-mpe@ellerman.id.au
2020-03-25 12:09:37 +11:00
..
syscalls threads-v5.6 2020-01-29 19:38:34 -08:00
trace powerpc/ftrace: Enable HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 2019-09-18 12:24:55 +10:00
vdso32 powerpc/vdso32: miscellaneous optimisations 2020-01-23 21:31:16 +11:00
vdso64 powerpc: Fix vDSO clock_getres() 2019-12-05 00:13:55 +11:00
.gitignore powerpc: improve prom_init_check rule 2019-09-14 00:04:41 +10:00
align.c powerpc/spe: Mark expected switch fall-throughs 2019-07-31 00:19:34 +10:00
asm-offsets.c powerpc/32s: Fix DSI and ISI exceptions for CONFIG_VMAP_STACK 2020-02-18 21:31:11 +11:00
audit.c
btext.c
cacheinfo.c powerpc updates for 5.3 2019-07-13 16:08:36 -07:00
cacheinfo.h powerpc/cacheinfo: add cacheinfo_teardown, cacheinfo_rebuild 2019-06-15 16:52:06 +10:00
compat_audit.c
cpu_setup_6xx.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cpu_setup_44x.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cpu_setup_fsl_booke.S powerpc/booke: Spelling s/date/data/ 2019-11-17 01:56:31 -06:00
cpu_setup_pa6t.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 333 2019-06-05 17:37:06 +02:00
cpu_setup_power.S powerpc/64s: Set reserved PCR bits 2019-09-21 08:36:53 +10:00
cpu_setup_ppc970.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
cputable.c powerpc: fix hardware PMU exception bug on PowerVM compatibility mode systems 2020-02-28 10:09:33 +11:00
crash_dump.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230 2019-06-19 17:09:06 +02:00
dawr.c powerpc/watchpoint: Fix length calculation for unaligned target 2019-11-13 16:58:03 +11:00
dbell.c KVM: PPC: Book3S HV: use smp_mb() when setting/clearing host_ipi flag 2019-09-24 12:46:26 +10:00
dma-iommu.c powerpc updates for 5.4 2019-09-20 11:48:06 -07:00
dma-mask.c dma-mapping, powerpc: simplify the arch dma_set_mask override 2019-02-18 22:41:03 +11:00
dma-swiotlb.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
dt_cpu_ftrs.c powerpc/64: Setup a paca before parsing device tree etc. 2020-03-25 12:09:37 +11:00
early_32.c powerpc/fsl_booke/32: implement KASLR infrastructure 2019-11-13 19:27:40 +11:00
eeh_cache.c powerpc/eeh_cache: Don't use pci_dn when inserting new ranges 2020-01-23 21:31:18 +11:00
eeh_dev.c powerpc/eeh: Add bdfn field to eeh_dev 2019-08-22 23:12:46 +10:00
eeh_driver.c powerpc/eeh: Fix deadlock handling dead PHB 2020-02-17 12:47:05 +11:00
eeh_event.c powerpc/eeh: Fix build with STACKTRACE=n 2019-09-14 00:01:14 +10:00
eeh_pe.c powerpc/eeh: Clean up EEH PEs after recovery finishes 2019-09-05 14:22:37 +10:00
eeh_sysfs.c powerpc/eeh_sysfs: Make clearing EEH_DEV_SYSFS saner 2020-01-23 21:31:19 +11:00
eeh.c powerpc/eeh: Only dump stack once if an MMIO loop is detected 2020-01-23 21:31:20 +11:00
entry_32.S Merge branch 'fixes' into next 2020-03-10 15:16:42 +11:00
entry_64.S powerpc updates for 5.6 2020-02-04 13:06:46 +00:00
epapr_hcalls.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
epapr_paravirt.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 266 2019-06-05 17:30:28 +02:00
exceptions-64e.S powerpc: unify definition of M_IF_NEEDED 2019-11-13 19:27:24 +11:00
exceptions-64s.S powerpc: Provide initial documentation for PAPR hcalls 2020-01-29 21:30:50 +11:00
fadump.c powerpc/kernel: no need to check return value of debugfs_create functions 2020-03-04 22:44:25 +11:00
firmware.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
fpu.S powerpc/32s: Enable CONFIG_VMAP_STACK 2020-01-27 22:37:24 +11:00
fsl_booke_entry_mapping.S powerpc/fsl_booke/32: implement KASLR infrastructure 2019-11-13 19:27:40 +11:00
head_8xx.S powerpc/8xx: Fix clearing of bits 20-23 in ITLB miss 2020-02-17 12:47:06 +11:00
head_32.h Merge branch 'fixes' into next 2020-03-10 15:16:42 +11:00
head_32.S powerpc/32s: reorder Linux PTE bits to better match Hash PTE bits. 2020-03-25 12:09:27 +11:00
head_40x.S powerpc/32: save DEAR/DAR before calling handle_page_fault 2020-01-26 22:15:09 +11:00
head_44x.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
head_64.S powerpc/64s: Fix section mismatch warnings from boot code 2020-03-25 12:07:59 +11:00
head_booke.h powerpc/32: Warn and return ENOSYS on syscalls from kernel 2020-02-19 22:46:08 +11:00
head_fsl_booke.S powerpc/32: save DEAR/DAR before calling handle_page_fault 2020-01-26 22:15:09 +11:00
hw_breakpoint.c powerpc/watchpoint: Don't call dar_within_range() for Book3S 2020-02-24 11:19:35 +11:00
idle_6xx.S powerpc/6xx: Fix power_save_ppc32_restore() with CONFIG_VMAP_STACK 2020-02-18 21:31:12 +11:00
idle_book3e.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
idle_book3s.S powerpc/64s: Reimplement power4_idle code in C 2020-01-16 14:59:37 +10:00
idle_e500.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
idle.c powerpc/64s: Reimplement power4_idle code in C 2020-01-16 14:59:37 +10:00
ima_arch.c powerpc/ima: Indicate kernel modules appended signatures are enforced 2019-11-12 12:25:50 +11:00
io-workarounds.c powerpc/mm: rework io-workaround invocation. 2019-08-27 13:03:34 +10:00
io.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
iomap.c
iommu.c Merge branch 'topic/ppc-kvm' into next 2019-08-30 09:52:57 +10:00
irq.c powerpc/irq: Use current_stack_pointer in do_IRQ() 2020-03-04 22:44:30 +11:00
isa-bridge.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
jump_label.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
kgdb.c powerpc: Activate CONFIG_THREAD_INFO_IN_TASK 2019-02-23 22:31:40 +11:00
kprobes-ftrace.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
kprobes.c powerpc/kprobes: Remove redundant code 2020-03-25 12:09:08 +11:00
kvm_emul.S powerpc/kvm: Add ifdefs around template code 2019-09-14 00:04:40 +10:00
kvm.c powerpc/kvm: Explicitly mark kvm guest code as __init 2019-09-14 00:04:40 +10:00
l2cr_6xx.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 61 2019-05-24 17:36:45 +02:00
legacy_serial.c tty/serial: Migrate 8250_fsl to use has_sysrq 2019-12-18 15:04:42 +01:00
Makefile powerpc/64s: Reimplement power4_idle code in C 2020-01-16 14:59:37 +10:00
mce_power.c powerpc/mm/mce: Keep irqs disabled during lockless page table walk 2019-09-19 21:24:59 +10:00
mce.c powerpc/64s/pseries: machine check convert to use common event code 2019-08-30 10:32:35 +10:00
misc_32.S powerpc/32: Split kexec low level code out of misc_32.S 2019-11-21 15:41:34 +11:00
misc_64.S Merge branch 'topic/kaslr-book3e32' into next 2019-11-14 19:23:33 +11:00
misc.S powerpc: Rename current_stack_pointer() to current_stack_frame() 2020-03-04 22:44:28 +11:00
module_32.c powerpc updates for 5.3 2019-07-13 16:08:36 -07:00
module_64.c powerpc updates for 5.3 2019-07-13 16:08:36 -07:00
module.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
module.lds
msi.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
note.S powerpc: Add PowerPC Capabilities ELF note 2019-08-30 09:40:15 +10:00
nvram_64.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
of_platform.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
optprobes_head.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
optprobes.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
paca.c powerpc/64: Setup a paca before parsing device tree etc. 2020-03-25 12:09:37 +11:00
pci_32.c powerpc/64: Adjust order in pcibios_init() 2019-08-22 23:11:48 +10:00
pci_64.c powerpc/64: Adjust order in pcibios_init() 2019-08-22 23:11:48 +10:00
pci_dn.c powerpc/pcidn: Warn when sriov pci_dn management is used incorrectly 2020-01-23 21:31:19 +11:00
pci_of_scan.c powerpc/pci: Remove pcibios_setup_bus_devices() 2020-01-06 16:25:29 +11:00
pci-common.c powerpc/pci: Fold pcibios_setup_device() into pcibios_bus_add_device() 2020-01-23 21:31:21 +11:00
pci-hotplug.c powerpc/pci: Remove pcibios_setup_bus_devices() 2020-01-06 16:25:29 +11:00
pmc.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ppc32.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
ppc_save_regs.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
proc_powerpc.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
process.c powerpc: Rename current_stack_pointer() to current_stack_frame() 2020-03-04 22:44:28 +11:00
prom_init_check.sh powerpc/prom_init: Undo relocation before entering secure mode 2019-10-29 15:12:17 +11:00
prom_init.c powerpc/prom_init: Pass the "os-term" message to hypervisor 2020-03-25 12:07:58 +11:00
prom_parse.c
prom.c powerpc/fadump: add support to preserve crash data on FADUMP disabled kernel 2019-09-14 00:04:45 +10:00
ptrace32.c
ptrace.c powerpc/watchpoint: Fix ptrace code that muck around with address/len 2019-11-13 16:58:03 +11:00
reloc_32.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
reloc_64.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
rtas_flash.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
rtas_pci.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
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: allow rescheduling while changing cpu states 2019-08-20 21:22:27 +10:00
rtasd.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
secure_boot.c powerpc: Detect the trusted boot state of the system 2019-11-12 12:25:49 +11:00
security.c powerpc updates for 5.5 2019-11-30 14:35:43 -08:00
secvar-ops.c powerpc/powernv: Add OPAL API interface to access secure variable 2019-11-13 00:33:22 +11:00
secvar-sysfs.c powerpc: expose secure variables to userspace via sysfs 2019-11-13 00:33:22 +11:00
setup_32.c powerpc/32: Use vmapped stacks for interrupts 2020-01-27 22:36:15 +11:00
setup_64.c powerpc/64: Setup a paca before parsing device tree etc. 2020-03-25 12:09:37 +11:00
setup-common.c powerpc/kernel: no need to check return value of debugfs_create functions 2020-03-04 22:44:25 +11:00
setup.h powerpc/32: Add early stack overflow detection with VMAP stack. 2020-01-27 22:35:49 +11:00
signal_32.c powerpc/tm: Fix clearing MSR[TS] in current when reclaiming on signal delivery 2020-02-18 21:30:42 +11:00
signal_64.c powerpc/tm: Fix clearing MSR[TS] in current when reclaiming on signal delivery 2020-02-18 21:30:42 +11:00
signal.c powerpc/tm: Fix clearing MSR[TS] in current when reclaiming on signal delivery 2020-02-18 21:30:42 +11:00
signal.h
smp-tbsync.c
smp.c powerpc/numa: Remove late request for home node associativity 2020-03-04 22:44:31 +11:00
stacktrace.c powerpc: Rename current_stack_pointer() to current_stack_frame() 2020-03-04 22:44:28 +11:00
suspend.c PM: hibernate: powerpc: Expose pfn_is_nosave() prototype 2019-06-14 10:48:56 +02:00
swsusp_32.S powerpc/32s: fix suspend/resume when IBATs 4-7 are used 2019-06-19 20:05:07 +10:00
swsusp_64.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505 2019-06-19 17:11:22 +02:00
swsusp_asm64.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505 2019-06-19 17:11:22 +02:00
swsusp_booke.S
swsusp.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
sys_ppc32.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
syscalls.c y2038: syscalls: change remaining timeval to __kernel_old_timeval 2019-11-15 14:38:29 +01:00
sysfs.c powerpc/kernel/sysfs: Add new config option PMU_SYSFS to enable PMU SPRs sysfs file creation 2020-03-04 22:44:28 +11:00
systbl_chk.sh treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
systbl.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
tau_6xx.c
time.c powerpc: Fix vDSO clock_getres() 2019-12-05 00:13:55 +11:00
tm.S powerpc/tm: update comment about interrupt re-entrancy 2019-07-02 21:39:49 +10:00
traps.c powerpc/kernel: no need to check return value of debugfs_create functions 2020-03-04 22:44:25 +11:00
ucall.S powerpc/kernel: Add ucall_norets() ultravisor call handler 2019-08-30 09:40:15 +10:00
udbg_16550.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
udbg.c powerpc/udbg: Make it safe to call udbg_printf() always 2019-10-11 19:33:25 +11:00
uprobes.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156 2019-05-30 11:26:35 -07:00
vdso.c powerpc/vdso: remove deprecated VDS64_HAS_DESCRIPTORS references 2020-03-13 21:13:06 +11:00
vecemu.c
vector.S powerpc/32s: Enable CONFIG_VMAP_STACK 2020-01-27 22:37:24 +11:00
vmlinux.lds.S powerpc: Include .BTF section 2020-02-24 22:04:07 +11:00
watchdog.c powerpc/watchdog: Use hrtimers for per-CPU heartbeat 2019-04-30 11:31:02 +10:00