linux/arch/powerpc/kernel
Michael Neuling c1fe190c06 powerpc: Add force enable of DAWR on P9 option
This adds a flag so that the DAWR can be enabled on P9 via:
  echo Y > /sys/kernel/debug/powerpc/dawr_enable_dangerous

The DAWR was previously force disabled on POWER9 in:
  9654153158 powerpc: Disable DAWR in the base POWER9 CPU features
Also see Documentation/powerpc/DAWR-POWER9.txt

This is a dangerous setting, USE AT YOUR OWN RISK.

Some users may not care about a bad user crashing their box
(ie. single user/desktop systems) and really want the DAWR.  This
allows them to force enable DAWR.

This flag can also be used to disable DAWR access. Once this is
cleared, all DAWR access should be cleared immediately and your
machine once again safe from crashing.

Userspace may get confused by toggling this. If DAWR is force
enabled/disabled between getting the number of breakpoints (via
PTRACE_GETHWDBGINFO) and setting the breakpoint, userspace will get an
inconsistent view of what's available. Similarly for guests.

For the DAWR to be enabled in a KVM guest, the DAWR needs to be force
enabled in the host AND the guest. For this reason, this won't work on
POWERVM as it doesn't allow the HCALL to work. Writes of 'Y' to the
dawr_enable_dangerous file will fail if the hypervisor doesn't support
writing the DAWR.

To double check the DAWR is working, run this kernel selftest:
  tools/testing/selftests/powerpc/ptrace/ptrace-hwbreak.c
Any errors/failures/skips mean something is wrong.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-04-20 22:20:45 +10:00
..
syscalls powerpc updates for 5.1 2019-03-07 12:56:26 -08:00
trace powerpc/64: Replace CURRENT_THREAD_INFO with PACA_THREAD_INFO 2019-02-23 22:31:40 +11:00
vdso32 powerpc: Enable kcov 2019-02-23 21:04:32 +11:00
vdso64 powerpc/vdso64: Fix CLOCK_MONOTONIC inconsistencies across Y2038 2019-03-18 19:26:38 +11:00
.gitignore
align.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
asm-offsets.c powerpc/64: Replace CURRENT_THREAD_INFO with PACA_THREAD_INFO 2019-02-23 22:31:40 +11:00
audit.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
btext.c powerpc: Rework btext_find_display to use of_stdout and device_type helpers 2018-11-26 22:33:37 +11:00
cacheinfo.c powerpc: Use device_type helpers to access the node type 2018-11-26 22:33:37 +11:00
cacheinfo.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat_audit.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
cpu_setup_6xx.S powerpc/6xx: fix setup and use of SPRN_SPRG_PGDIR for hash32 2019-03-19 00:30:19 +11:00
cpu_setup_44x.S
cpu_setup_fsl_booke.S powerpc/mm: move platform specific mmu-xxx.h in platform directories 2018-12-04 19:45:01 +11:00
cpu_setup_pa6t.S
cpu_setup_power.S powerpc: Turn off CPU_FTR_P9_TM_HV_ASSIST in non-hypervisor mode 2018-10-09 16:04:27 +11:00
cpu_setup_ppc970.S
cputable.c powerpc/83xx: handle machine check caused by watchdog timer 2018-12-21 20:56:41 -06:00
crash_dump.c powerpc: don't use ioremap_prot() nor __ioremap() unless really needed. 2018-10-14 18:04:09 +11:00
crash.c powerpc: remove kdump.h from page.h 2018-07-30 22:47:53 +10:00
dbell.c
dma-iommu.c powerpc/dma: use the dma_direct mapping routines 2019-02-18 22:41:04 +11:00
dma-mask.c dma-mapping, powerpc: simplify the arch dma_set_mask override 2019-02-18 22:41:03 +11:00
dma-swiotlb.c powerpc/dma: use the generic direct mapping bypass 2019-02-18 22:41:04 +11:00
dt_cpu_ftrs.c treewide: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
eeh_cache.c powerpc/eeh_cache: Bump log level of eeh_addr_cache_print() 2019-02-22 00:10:14 +11:00
eeh_dev.c powerpc/eeh: Cleanup list_head field names 2018-10-13 22:21:25 +11:00
eeh_driver.c powerpc/eeh: Improve recovery of passed-through devices 2019-02-05 11:55:44 +11:00
eeh_event.c powerpc/eeh: Add eeh_force_recover to debugfs 2019-02-22 00:10:15 +11:00
eeh_pe.c powerpc/eeh: Add include_passed to eeh_pe_state_clear() 2019-02-05 11:55:43 +11:00
eeh_sysfs.c powerpc/eeh: Add include_passed to eeh_pe_state_clear() 2019-02-05 11:55:43 +11:00
eeh.c powerpc/eeh: Add eeh_force_recover to debugfs 2019-02-22 00:10:15 +11:00
entry_32.S powerpc/32: Clear on-stack exception marker upon exception return 2019-03-04 00:37:23 +11:00
entry_64.S powerpc/64: Replace CURRENT_THREAD_INFO with PACA_THREAD_INFO 2019-02-23 22:31:40 +11:00
epapr_hcalls.S powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU 2019-02-23 22:31:40 +11:00
epapr_paravirt.c
exceptions-64e.S powerpc/fsl: Fix the flush of branch predictor. 2019-02-27 22:52:38 +11:00
exceptions-64s.S powerpc/64s: Fix unrelocated interrupt trampoline address test 2019-03-02 00:25:47 +11:00
fadump.c powerpc/fadump: Do not allow hot-remove memory from fadump reserved area. 2018-12-21 11:32:49 +11:00
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 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
head_8xx.S powerpc: Rename THREAD_INFO to TASK_STACK 2019-02-23 22:31:40 +11:00
head_32.S powerpc/6xx: fix setup and use of SPRN_SPRG_PGDIR for hash32 2019-03-19 00:30:19 +11:00
head_40x.S powerpc: Rename THREAD_INFO to TASK_STACK 2019-02-23 22:31:40 +11:00
head_44x.S powerpc: 'current_set' is now a table of task_struct pointers 2019-02-23 22:31:40 +11:00
head_64.S powerpc/64: Simplify __secondary_start paca->kstack handling 2019-02-23 22:31:39 +11:00
head_booke.h powerpc: Activate CONFIG_THREAD_INFO_IN_TASK 2019-02-23 22:31:40 +11:00
head_fsl_booke.S powerpc: remove dead code in head_fsl_booke.S 2019-03-05 16:38:45 +11:00
hw_breakpoint.c powerpc: Add force enable of DAWR on P9 option 2019-04-20 22:20:45 +10:00
idle_6xx.S powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU 2019-02-23 22:31:40 +11:00
idle_book3e.S powerpc/64: Replace CURRENT_THREAD_INFO with PACA_THREAD_INFO 2019-02-23 22:31:40 +11:00
idle_book3s.S Merge branch 'fixes' into next 2018-08-13 15:59:06 +10:00
idle_e500.S powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU 2019-02-23 22:31:40 +11:00
idle_power4.S powerpc/64: Replace CURRENT_THREAD_INFO with PACA_THREAD_INFO 2019-02-23 22:31:40 +11:00
idle.c
ima_kexec.c
io-workarounds.c powerpc: handover page flags with a pgprot_t parameter 2018-10-14 18:04:09 +11:00
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 IOMMU Updates for Linux v4.21 2019-01-01 15:55:29 -08:00
irq.c powerpc: clean stack pointers naming 2019-02-23 22:31:40 +11:00
isa-bridge.c powerpc: Use device_type helpers to access the node type 2018-11-26 22:33:37 +11:00
jump_label.c jump_label: move 'asm goto' support test to Kconfig 2019-01-06 09:46:51 +09:00
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 powerpc: Activate CONFIG_THREAD_INFO_IN_TASK 2019-02-23 22:31:40 +11:00
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 powerpc/kvm: Prefer fault_in_pages_readable function 2018-05-17 14:12:40 +10:00
l2cr_6xx.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
legacy_serial.c powerpc: Use of_node_name_eq for node name comparisons 2018-12-22 21:29:50 +11:00
machine_kexec_32.c
machine_kexec_64.c powerpc: Activate CONFIG_THREAD_INFO_IN_TASK 2019-02-23 22:31:40 +11:00
machine_kexec_file_64.c powerpc, kexec_file: factor out memblock-based arch_kexec_walk_mem() 2018-12-06 14:38:50 +00:00
machine_kexec.c powerpc: remove kdump.h from page.h 2018-07-30 22:47:53 +10:00
Makefile powerpc: Enable kcov 2019-02-23 21:04:32 +11:00
mce_power.c powerpc/64s/hash: Do not use PPC_INVALIDATE_ERAT on CPUs before POWER9 2018-10-04 23:16:53 +10:00
mce.c powerpc/64s: Fix HV NMI vs HV interrupt recoverability test 2019-02-26 23:28:24 +11:00
misc_32.S powerpc/32: Remove CURRENT_THREAD_INFO and rename TI_CPU 2019-02-23 22:31:40 +11:00
misc_64.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
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 2018-10-20 13:26:47 +11:00
module.c powerpc64/module elfv1: Set opd addresses after module relocation 2018-10-20 13:26:47 +11:00
module.lds powerpc/modules: Fix alignment of .toc section in kernel modules 2017-12-11 13:03:35 +11:00
msi.c powerpc/msi: Fix NULL pointer access in teardown code 2018-11-29 23:49:11 +11:00
nvram_64.c powerpc: Adopt nvram module for PPC64 2019-01-22 10:21:45 +01:00
of_platform.c
optprobes_head.S powerpc/64: Rename soft_enabled to irq_soft_mask 2018-01-19 22:37:01 +11:00
optprobes.c powerpc/kprobes: Do not disable interrupts for optprobes and kprobes_on_ftrace 2017-11-12 23:51:41 +11:00
paca.c powerpc: use memblock functions returning virtual address 2019-03-12 10:04:01 -07:00
pci_32.c treewide: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
pci_64.c powerpc: handover page flags with a pgprot_t parameter 2018-10-14 18:04:09 +11:00
pci_dn.c powerpc/pci: Separate SR-IOV Calls 2017-12-11 13:03:35 +11:00
pci_of_scan.c powerpc: Use device_type helpers to access the node type 2018-11-26 22:33:37 +11:00
pci-common.c powerpc updates for 5.1 2019-03-07 12:56:26 -08:00
pci-hotplug.c powerpc/pci: Unroll two pass loop when scanning bridges 2017-12-18 23:05:52 -06:00
pmc.c powerpc: change CONFIG_6xx to CONFIG_PPC_BOOK3S_32 2018-11-26 22:33:37 +11:00
ppc32.h
ppc_save_regs.S powerpc: move ASM_CONST and stringify_in_c() into asm-const.h 2018-07-30 22:48:16 +10:00
proc_powerpc.c powerpc: Use octal numbers for file permissions 2018-01-22 05:48:33 +11:00
process.c powerpc: Add force enable of DAWR on P9 option 2019-04-20 22:20:45 +10:00
prom_init_check.sh powerpc: Check prom_init for disallowed sections 2018-10-19 00:56:17 +11:00
prom_init.c powerpc/prom_init: Generate "phandle" instead of "linux, phandle" 2018-10-19 00:56:17 +11:00
prom_parse.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
prom.c powerpc: use memblock functions returning virtual address 2019-03-12 10:04:01 -07:00
ptrace32.c
ptrace.c powerpc: Add force enable of DAWR on P9 option 2019-04-20 22:20:45 +10:00
reloc_32.S
reloc_64.S
rtas_flash.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
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 memblock: drop memblock_alloc_base() 2019-03-12 10:04:01 -07:00
rtasd.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
security.c powerpc/security: Fix spectre_v2 reporting 2019-03-21 21:09:03 +11:00
setup_32.c powerpc updates for 5.1 2019-03-07 12:56:26 -08:00
setup_64.c treewide: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
setup-common.c treewide: add checks for the return value of memblock_alloc*() 2019-03-12 10:04:02 -07:00
setup.h powerpc/tau: Synchronize function prototypes and body 2018-05-25 12:04:43 +10:00
signal_32.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
signal_64.c powerpc/tm: Limit TM code inside PPC_TRANSACTIONAL_MEM 2019-01-11 23:45:00 +11:00
signal.c Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
signal.h powerpc/syscalls: signal_{32, 64} - switch to SYSCALL_DEFINE 2018-05-10 23:25:13 +10:00
smp-tbsync.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
smp.c powerpc: 'current_set' is now a table of task_struct pointers 2019-02-23 22:31:40 +11:00
stacktrace.c powerpc: Remove export of save_stack_trace_tsk_reliable() 2019-03-02 14:43:05 +11:00
suspend.c
swsusp_32.S powerpc: clean inclusions of asm/feature-fixups.h 2018-07-30 22:48:17 +10:00
swsusp_64.c
swsusp_asm64.S powerpc/64s/hash: Simplify slb_flush_and_rebolt() 2018-10-14 18:04:09 +11:00
swsusp_booke.S License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
swsusp.c
sys_ppc32.c powerpc/syscalls: kill ppc32_select() 2018-05-10 23:25:15 +10:00
syscalls.c powerpc/64: Make sys_switch_endian() traceable 2019-02-22 00:10:15 +11:00
sysfs.c powerpc: change CONFIG_6xx to CONFIG_PPC_BOOK3S_32 2018-11-26 22:33:37 +11:00
systbl_chk.sh powerpc: Make it clearer that systbl check errors are errors 2018-05-10 23:25:16 +10:00
systbl.S powerpc: remove nargs from __SYSCALL 2019-03-02 14:43:05 +11:00
tau_6xx.c powerpc/tau: Make some function static 2018-05-25 12:04:44 +10:00
time.c powerpc/kernel/time: Remove duplicate header 2019-01-30 23:42:31 +11:00
tm.S Merge branch 'fixes' into next 2018-10-09 16:51:05 +11:00
traps.c powerpc/64s: Include <asm/nmi.h> header file to fix a warning 2019-03-13 15:03:13 +11:00
udbg_16550.c
udbg.c powerpc: use a CONSOLE_LOGLEVEL_DEBUG macro 2019-01-14 20:39:27 +11:00
uprobes.c
vdso.c powerpc/vdso: don't clear PG_reserved 2019-03-05 21:07:18 -08:00
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/kconfig: define CONFIG_DATA_SHIFT and CONFIG_ETEXT_SHIFT 2019-02-23 21:04:32 +11:00
watchdog.c powerpc: NMI IPI make NMI IPIs fully sychronous 2018-07-24 22:03:14 +10:00