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[ Upstream commit d9101bfa6adc831bda8836c4d774820553c14942 ]
__find_linux_mm_pte() returns a page table entry pointer after walking
the page table without holding locks. To make it safe against a THP
split and/or collapse, we disable interrupts around the lockless page
table walk. However we need to keep interrupts disabled as long as we
use the page table entry pointer that is returned.
Fix addr_to_pfn() to do that.
Fixes: ba41e1e1ccb9 ("powerpc/mce: Hookup derror (load/store) UE errors")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
[mpe: Rearrange code slightly and tweak change log wording]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190918145328.28602-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit d4aa219a074a5abaf95a756b9f0d190b5c03a945 ]
Allow external callers to force the cacheinfo code to release all its
references to cache nodes, e.g. before processing device tree updates
post-migration, and to rebuild the hierarchy afterward.
CPU online/offline must be blocked by callers; enforce this.
Fixes: 410bccf97881 ("powerpc/pseries: Partition migration in the kernel")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 8cfaf106918a8c13abb24c641556172afbb9545c ]
In cpufeatures_process_feature(), if a provided CPU feature is unknown and
enable_unknown is false, we erroneously print that the feature is being
enabled and return true, even though no feature has been enabled, and
may also set feature bits based on the last entry in the match table.
Fix this so that we only set feature bits from the match table if we have
actually enabled a feature from that table, and when failing to enable an
unknown feature, always print the "not enabling" message and return false.
Coincidentally, some older gccs (<GCC 7), when invoked with
-fsanitize-coverage=trace-pc, cause a spurious uninitialised variable
warning in this function:
arch/powerpc/kernel/dt_cpu_ftrs.c: In function ‘cpufeatures_process_feature’:
arch/powerpc/kernel/dt_cpu_ftrs.c:686:7: warning: ‘m’ may be used uninitialized in this function [-Wmaybe-uninitialized]
if (m->cpu_ftr_bit_mask)
An upcoming patch will enable support for kcov, which requires this option.
This patch avoids the warning.
Fixes: 5a61ef74f269 ("powerpc/64s: Support new device tree binding for discovering CPU features")
Reported-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[ajd: add commit message]
Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit fb978ca207743badfe7efd9eebe68bcbb4969f79 ]
Generic implementation fails to remove breakpoints after init
when CONFIG_STRICT_KERNEL_RWX is selected:
[ 13.251285] KGDB: BP remove failed: c001c338
[ 13.259587] kgdbts: ERROR PUT: end of test buffer on 'do_fork_test' line 8 expected OK got $E14#aa
[ 13.268969] KGDB: re-enter exception: ALL breakpoints killed
[ 13.275099] CPU: 0 PID: 1 Comm: init Not tainted 4.18.0-g82bbb913ffd8 #860
[ 13.282836] Call Trace:
[ 13.285313] [c60e1ba0] [c0080ef0] kgdb_handle_exception+0x6f4/0x720 (unreliable)
[ 13.292618] [c60e1c30] [c000e97c] kgdb_handle_breakpoint+0x3c/0x98
[ 13.298709] [c60e1c40] [c000af54] program_check_exception+0x104/0x700
[ 13.305083] [c60e1c60] [c000e45c] ret_from_except_full+0x0/0x4
[ 13.310845] [c60e1d20] [c02a22ac] run_simple_test+0x2b4/0x2d4
[ 13.316532] [c60e1d30] [c0081698] put_packet+0xb8/0x158
[ 13.321694] [c60e1d60] [c00820b4] gdb_serial_stub+0x230/0xc4c
[ 13.327374] [c60e1dc0] [c0080af8] kgdb_handle_exception+0x2fc/0x720
[ 13.333573] [c60e1e50] [c000e928] kgdb_singlestep+0xb4/0xcc
[ 13.339068] [c60e1e70] [c000ae1c] single_step_exception+0x90/0xac
[ 13.345100] [c60e1e80] [c000e45c] ret_from_except_full+0x0/0x4
[ 13.350865] [c60e1f40] [c000e11c] ret_from_syscall+0x0/0x38
[ 13.356346] Kernel panic - not syncing: Recursive entry to debugger
This patch creates powerpc specific version of
kgdb_arch_set_breakpoint() and kgdb_arch_remove_breakpoint()
using patch_instruction()
Fixes: 1e0fc9d1eb2b ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 0a87ccd3699983645f54cafd2258514a716b20b8 upstream.
Advertise client support for the PAPR architected ibm,drc-info device
tree property during CAS handshake.
Fixes: c7a3275e0f9e ("powerpc/pseries: Revert support for ibm,drc-info devtree property")
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1573449697-5448-11-git-send-email-tyreld@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 3a83f677a6eeff65751b29e3648d7c69c3be83f3 ]
On a 2-socket Power9 system with 32 cores/128 threads (SMT4) and 1TB
of memory running the following guest configs:
guest A:
- 224GB of memory
- 56 VCPUs (sockets=1,cores=28,threads=2), where:
VCPUs 0-1 are pinned to CPUs 0-3,
VCPUs 2-3 are pinned to CPUs 4-7,
...
VCPUs 54-55 are pinned to CPUs 108-111
guest B:
- 4GB of memory
- 4 VCPUs (sockets=1,cores=4,threads=1)
with the following workloads (with KSM and THP enabled in all):
guest A:
stress --cpu 40 --io 20 --vm 20 --vm-bytes 512M
guest B:
stress --cpu 4 --io 4 --vm 4 --vm-bytes 512M
host:
stress --cpu 4 --io 4 --vm 2 --vm-bytes 256M
the below soft-lockup traces were observed after an hour or so and
persisted until the host was reset (this was found to be reliably
reproducible for this configuration, for kernels 4.15, 4.18, 5.0,
and 5.3-rc5):
[ 1253.183290] rcu: INFO: rcu_sched self-detected stall on CPU
[ 1253.183319] rcu: 124-....: (5250 ticks this GP) idle=10a/1/0x4000000000000002 softirq=5408/5408 fqs=1941
[ 1256.287426] watchdog: BUG: soft lockup - CPU#105 stuck for 23s! [CPU 52/KVM:19709]
[ 1264.075773] watchdog: BUG: soft lockup - CPU#24 stuck for 23s! [worker:19913]
[ 1264.079769] watchdog: BUG: soft lockup - CPU#31 stuck for 23s! [worker:20331]
[ 1264.095770] watchdog: BUG: soft lockup - CPU#45 stuck for 23s! [worker:20338]
[ 1264.131773] watchdog: BUG: soft lockup - CPU#64 stuck for 23s! [avocado:19525]
[ 1280.408480] watchdog: BUG: soft lockup - CPU#124 stuck for 22s! [ksmd:791]
[ 1316.198012] rcu: INFO: rcu_sched self-detected stall on CPU
[ 1316.198032] rcu: 124-....: (21003 ticks this GP) idle=10a/1/0x4000000000000002 softirq=5408/5408 fqs=8243
[ 1340.411024] watchdog: BUG: soft lockup - CPU#124 stuck for 22s! [ksmd:791]
[ 1379.212609] rcu: INFO: rcu_sched self-detected stall on CPU
[ 1379.212629] rcu: 124-....: (36756 ticks this GP) idle=10a/1/0x4000000000000002 softirq=5408/5408 fqs=14714
[ 1404.413615] watchdog: BUG: soft lockup - CPU#124 stuck for 22s! [ksmd:791]
[ 1442.227095] rcu: INFO: rcu_sched self-detected stall on CPU
[ 1442.227115] rcu: 124-....: (52509 ticks this GP) idle=10a/1/0x4000000000000002 softirq=5408/5408 fqs=21403
[ 1455.111787] INFO: task worker:19907 blocked for more than 120 seconds.
[ 1455.111822] Tainted: G L 5.3.0-rc5-mdr-vanilla+ #1
[ 1455.111833] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1455.111884] INFO: task worker:19908 blocked for more than 120 seconds.
[ 1455.111905] Tainted: G L 5.3.0-rc5-mdr-vanilla+ #1
[ 1455.111925] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1455.111966] INFO: task worker:20328 blocked for more than 120 seconds.
[ 1455.111986] Tainted: G L 5.3.0-rc5-mdr-vanilla+ #1
[ 1455.111998] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1455.112048] INFO: task worker:20330 blocked for more than 120 seconds.
[ 1455.112068] Tainted: G L 5.3.0-rc5-mdr-vanilla+ #1
[ 1455.112097] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1455.112138] INFO: task worker:20332 blocked for more than 120 seconds.
[ 1455.112159] Tainted: G L 5.3.0-rc5-mdr-vanilla+ #1
[ 1455.112179] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1455.112210] INFO: task worker:20333 blocked for more than 120 seconds.
[ 1455.112231] Tainted: G L 5.3.0-rc5-mdr-vanilla+ #1
[ 1455.112242] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1455.112282] INFO: task worker:20335 blocked for more than 120 seconds.
[ 1455.112303] Tainted: G L 5.3.0-rc5-mdr-vanilla+ #1
[ 1455.112332] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 1455.112372] INFO: task worker:20336 blocked for more than 120 seconds.
[ 1455.112392] Tainted: G L 5.3.0-rc5-mdr-vanilla+ #1
CPUs 45, 24, and 124 are stuck on spin locks, likely held by
CPUs 105 and 31.
CPUs 105 and 31 are stuck in smp_call_function_many(), waiting on
target CPU 42. For instance:
# CPU 105 registers (via xmon)
R00 = c00000000020b20c R16 = 00007d1bcd800000
R01 = c00000363eaa7970 R17 = 0000000000000001
R02 = c0000000019b3a00 R18 = 000000000000006b
R03 = 000000000000002a R19 = 00007d537d7aecf0
R04 = 000000000000002a R20 = 60000000000000e0
R05 = 000000000000002a R21 = 0801000000000080
R06 = c0002073fb0caa08 R22 = 0000000000000d60
R07 = c0000000019ddd78 R23 = 0000000000000001
R08 = 000000000000002a R24 = c00000000147a700
R09 = 0000000000000001 R25 = c0002073fb0ca908
R10 = c000008ffeb4e660 R26 = 0000000000000000
R11 = c0002073fb0ca900 R27 = c0000000019e2464
R12 = c000000000050790 R28 = c0000000000812b0
R13 = c000207fff623e00 R29 = c0002073fb0ca808
R14 = 00007d1bbee00000 R30 = c0002073fb0ca800
R15 = 00007d1bcd600000 R31 = 0000000000000800
pc = c00000000020b260 smp_call_function_many+0x3d0/0x460
cfar= c00000000020b270 smp_call_function_many+0x3e0/0x460
lr = c00000000020b20c smp_call_function_many+0x37c/0x460
msr = 900000010288b033 cr = 44024824
ctr = c000000000050790 xer = 0000000000000000 trap = 100
CPU 42 is running normally, doing VCPU work:
# CPU 42 stack trace (via xmon)
[link register ] c00800001be17188 kvmppc_book3s_radix_page_fault+0x90/0x2b0 [kvm_hv]
[c000008ed3343820] c000008ed3343850 (unreliable)
[c000008ed33438d0] c00800001be11b6c kvmppc_book3s_hv_page_fault+0x264/0xe30 [kvm_hv]
[c000008ed33439d0] c00800001be0d7b4 kvmppc_vcpu_run_hv+0x8dc/0xb50 [kvm_hv]
[c000008ed3343ae0] c00800001c10891c kvmppc_vcpu_run+0x34/0x48 [kvm]
[c000008ed3343b00] c00800001c10475c kvm_arch_vcpu_ioctl_run+0x244/0x420 [kvm]
[c000008ed3343b90] c00800001c0f5a78 kvm_vcpu_ioctl+0x470/0x7c8 [kvm]
[c000008ed3343d00] c000000000475450 do_vfs_ioctl+0xe0/0xc70
[c000008ed3343db0] c0000000004760e4 ksys_ioctl+0x104/0x120
[c000008ed3343e00] c000000000476128 sys_ioctl+0x28/0x80
[c000008ed3343e20] c00000000000b388 system_call+0x5c/0x70
--- Exception: c00 (System Call) at 00007d545cfd7694
SP (7d53ff7edf50) is in userspace
It was subsequently found that ipi_message[PPC_MSG_CALL_FUNCTION]
was set for CPU 42 by at least 1 of the CPUs waiting in
smp_call_function_many(), but somehow the corresponding
call_single_queue entries were never processed by CPU 42, causing the
callers to spin in csd_lock_wait() indefinitely.
Nick Piggin suggested something similar to the following sequence as
a possible explanation (interleaving of CALL_FUNCTION/RESCHEDULE
IPI messages seems to be most common, but any mix of CALL_FUNCTION and
!CALL_FUNCTION messages could trigger it):
CPU
X: smp_muxed_ipi_set_message():
X: smp_mb()
X: message[RESCHEDULE] = 1
X: doorbell_global_ipi(42):
X: kvmppc_set_host_ipi(42, 1)
X: ppc_msgsnd_sync()/smp_mb()
X: ppc_msgsnd() -> 42
42: doorbell_exception(): // from CPU X
42: ppc_msgsync()
105: smp_muxed_ipi_set_message():
105: smb_mb()
// STORE DEFERRED DUE TO RE-ORDERING
--105: message[CALL_FUNCTION] = 1
| 105: doorbell_global_ipi(42):
| 105: kvmppc_set_host_ipi(42, 1)
| 42: kvmppc_set_host_ipi(42, 0)
| 42: smp_ipi_demux_relaxed()
| 42: // returns to executing guest
| // RE-ORDERED STORE COMPLETES
->105: message[CALL_FUNCTION] = 1
105: ppc_msgsnd_sync()/smp_mb()
105: ppc_msgsnd() -> 42
42: local_paca->kvm_hstate.host_ipi == 0 // IPI ignored
105: // hangs waiting on 42 to process messages/call_single_queue
This can be prevented with an smp_mb() at the beginning of
kvmppc_set_host_ipi(), such that stores to message[<type>] (or other
state indicated by the host_ipi flag) are ordered vs. the store to
to host_ipi.
However, doing so might still allow for the following scenario (not
yet observed):
CPU
X: smp_muxed_ipi_set_message():
X: smp_mb()
X: message[RESCHEDULE] = 1
X: doorbell_global_ipi(42):
X: kvmppc_set_host_ipi(42, 1)
X: ppc_msgsnd_sync()/smp_mb()
X: ppc_msgsnd() -> 42
42: doorbell_exception(): // from CPU X
42: ppc_msgsync()
// STORE DEFERRED DUE TO RE-ORDERING
-- 42: kvmppc_set_host_ipi(42, 0)
| 42: smp_ipi_demux_relaxed()
| 105: smp_muxed_ipi_set_message():
| 105: smb_mb()
| 105: message[CALL_FUNCTION] = 1
| 105: doorbell_global_ipi(42):
| 105: kvmppc_set_host_ipi(42, 1)
| // RE-ORDERED STORE COMPLETES
-> 42: kvmppc_set_host_ipi(42, 0)
42: // returns to executing guest
105: ppc_msgsnd_sync()/smp_mb()
105: ppc_msgsnd() -> 42
42: local_paca->kvm_hstate.host_ipi == 0 // IPI ignored
105: // hangs waiting on 42 to process messages/call_single_queue
Fixing this scenario would require an smp_mb() *after* clearing
host_ipi flag in kvmppc_set_host_ipi() to order the store vs.
subsequent processing of IPI messages.
To handle both cases, this patch splits kvmppc_set_host_ipi() into
separate set/clear functions, where we execute smp_mb() prior to
setting host_ipi flag, and after clearing host_ipi flag. These
functions pair with each other to synchronize the sender and receiver
sides.
With that change in place the above workload ran for 20 hours without
triggering any lock-ups.
Fixes: 755563bc79c7 ("powerpc/powernv: Fixes for hypervisor doorbell handling") # v4.0
Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190911223155.16045-1-mdroth@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 4e706af3cd8e1d0503c25332b30cad33c97ed442 ]
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>
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[ Upstream commit 8e6b6da91ac9b9ec5a925b6cb13f287a54bd547d ]
Some PowerPC CPUs are vulnerable to L1TF to the same extent as to
Meltdown. It is also mitigated by flushing the L1D on privilege
transition.
Currently the sysfs gives a false negative on L1TF on CPUs that I
verified to be vulnerable, a Power9 Talos II Boston 004e 1202, PowerNV
T2P9D01.
Signed-off-by: Anthony Steinhauser <asteinhauser@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[mpe: Just have cpu_show_l1tf() call cpu_show_meltdown() directly]
Link: https://lore.kernel.org/r/20191029190759.84821-1-asteinhauser@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit eb8e20f89093b64f48975c74ccb114e6775cee22 ]
accumulate_stolen_time() is called prior to interrupt state being
reconciled, which can trip the warning in arch_local_irq_restore():
WARNING: CPU: 5 PID: 1017 at arch/powerpc/kernel/irq.c:258 .arch_local_irq_restore+0x9c/0x130
...
NIP .arch_local_irq_restore+0x9c/0x130
LR .rb_start_commit+0x38/0x80
Call Trace:
.ring_buffer_lock_reserve+0xe4/0x620
.trace_function+0x44/0x210
.function_trace_call+0x148/0x170
.ftrace_ops_no_ops+0x180/0x1d0
ftrace_call+0x4/0x8
.accumulate_stolen_time+0x1c/0xb0
decrementer_common+0x124/0x160
For now just mark it as notrace. We may change the ordering to call it
after interrupt state has been reconciled, but that is a larger
change.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024055932.27940-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 099bc4812f09155da77eeb960a983470249c9ce1 upstream.
Before commit 0366a1c70b89 ("powerpc/irq: Run softirqs off the top of
the irq stack"), check_stack_overflow() was called by do_IRQ(), before
switching to the irq stack.
In that commit, do_IRQ() was renamed __do_irq(), and is now executing
on the irq stack, so check_stack_overflow() has just become almost
useless.
Move check_stack_overflow() call in do_IRQ() to do the check while
still on the current stack.
Fixes: 0366a1c70b89 ("powerpc/irq: Run softirqs off the top of the irq stack")
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e033aa8116ab12b7ca9a9c75189ad0741e3b9b5f.1575872340.git.christophe.leroy@c-s.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 552263456215ada7ee8700ce022d12b0cffe4802 ]
clock_getres in the vDSO library has to preserve the same behaviour
of posix_get_hrtimer_res().
In particular, posix_get_hrtimer_res() does:
sec = 0;
ns = hrtimer_resolution;
and hrtimer_resolution depends on the enablement of the high
resolution timers that can happen either at compile or at run time.
Fix the powerpc vdso implementation of clock_getres keeping a copy of
hrtimer_resolution in vdso data and using that directly.
Fixes: a7f290dad32e ("[PATCH] powerpc: Merge vdso's and add vdso support to 32 bits kernel")
Cc: stable@vger.kernel.org
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Shuah Khan <skhan@linuxfoundation.org>
[chleroy: changed CLOCK_REALTIME_RES to CLOCK_HRTIMER_RES]
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/a55eca3a5e85233838c2349783bcb5164dae1d09.1575273217.git.christophe.leroy@c-s.fr
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit c9029ef9c95765e7b63c4d9aa780674447db1ec0 ]
Commit aea447141c7e ("powerpc: Disable -Wbuiltin-requires-header when
setjmp is used") disabled -Wbuiltin-requires-header because of a
warning about the setjmp and longjmp declarations.
r367387 in clang added another diagnostic around this, complaining
that there is no jmp_buf declaration.
In file included from ../arch/powerpc/xmon/xmon.c:47:
../arch/powerpc/include/asm/setjmp.h:10:13: error: declaration of
built-in function 'setjmp' requires the declaration of the 'jmp_buf'
type, commonly provided in the header <setjmp.h>.
[-Werror,-Wincomplete-setjmp-declaration]
extern long setjmp(long *);
^
../arch/powerpc/include/asm/setjmp.h:11:13: error: declaration of
built-in function 'longjmp' requires the declaration of the 'jmp_buf'
type, commonly provided in the header <setjmp.h>.
[-Werror,-Wincomplete-setjmp-declaration]
extern void longjmp(long *, long);
^
2 errors generated.
We are not using the standard library's longjmp/setjmp implementations
for obvious reasons; make this clear to clang by using -ffreestanding
on these files.
Cc: stable@vger.kernel.org # 4.14+
Suggested-by: Segher Boessenkool <segher@kernel.crashing.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191119045712.39633-3-natechancellor@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 29430fae82073d39b1b881a3cd507416a56a363f upstream.
When calling flush_icache_range with a size >4GB, we were masking
off the upper 32 bits, so we would incorrectly flush a range smaller
than intended.
This patch replaces the 32 bit shifts with 64 bit ones, so that
the full size is accounted for.
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104023305.9581-2-alastair@au1.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f9ec11165301982585e5e5f606739b5bae5331f3 upstream.
When calling __kernel_sync_dicache with a size >4GB, we were masking
off the upper 32 bits, so we would incorrectly flush a range smaller
than intended.
This patch replaces the 32 bit shifts with 64 bit ones, so that
the full size is accounted for.
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Cc: stable@vger.kernel.org
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191104023305.9581-3-alastair@au1.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 505a314fb28ce122091691c51426fa85c084e115 ]
HMIs will crash the kernel due to
BRANCH_LINK_TO_FAR(hmi_exception_realmode)
Calling into the OPD instead of the actual code.
Fixes: 2337d207288f ("powerpc/64: CONFIG_RELOCATABLE support for hmi interrupts")
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
[mpe: Use DOTSYM() rather than #ifdef]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 0deae39cec6dab3a66794f3e9e83ca4dc30080f1 ]
When the watchdog timer is set in interrupt mode, it causes a
machine check when it times out. The purpose of this mode is to
ease debugging, not to crash the kernel and reboot the machine.
This patch implements a special handling for that, in order to not
crash the kernel if the watchdog times out while in interrupt or
within the idle task.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[scottwood: added missing #include]
Signed-off-by: Scott Wood <oss@buserror.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b18f0ae92b0a1db565c3e505fa87b6971ad3b641 ]
This patch fixes early DEBUG messages in prom.c:
- Use %px instead of %p to see the addresses
- Cast memblock_phys_mem_size() with (unsigned long long) to
avoid build failure when phys_addr_t is not 64 bits.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit af2e8c68b9c5403f77096969c516f742f5bb29e0 upstream.
On some systems that are vulnerable to Spectre v2, it is up to
software to flush the link stack (return address stack), in order to
protect against Spectre-RSB.
When exiting from a guest we do some house keeping and then
potentially exit to C code which is several stack frames deep in the
host kernel. We will then execute a series of returns without
preceeding calls, opening up the possiblity that the guest could have
poisoned the link stack, and direct speculative execution of the host
to a gadget of some sort.
To prevent this we add a flush of the link stack on exit from a guest.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
[dja: straightforward backport to v4.19]
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 39e72bf96f5847ba87cc5bd7a3ce0fed813dc9ad upstream.
In commit ee13cb249fab ("powerpc/64s: Add support for software count
cache flush"), I added support for software to flush the count
cache (indirect branch cache) on context switch if firmware told us
that was the required mitigation for Spectre v2.
As part of that code we also added a software flush of the link
stack (return address stack), which protects against Spectre-RSB
between user processes.
That is all correct for CPUs that activate that mitigation, which is
currently Power9 Nimbus DD2.3.
What I got wrong is that on older CPUs, where firmware has disabled
the count cache, we also need to flush the link stack on context
switch.
To fix it we create a new feature bit which is not set by firmware,
which tells us we need to flush the link stack. We set that when
firmware tells us that either of the existing Spectre v2 mitigations
are enabled.
Then we adjust the patching code so that if we see that feature bit we
enable the link stack flush. If we're also told to flush the count
cache in software then we fall through and do that also.
On the older CPUs we don't need to do do the software count cache
flush, firmware has disabled it, so in that case we patch in an early
return after the link stack flush.
The naming of some of the functions is awkward after this patch,
because they're called "count cache" but they also do link stack. But
we'll fix that up in a later commit to ease backporting.
This is the fix for CVE-2019-18660.
Reported-by: Anthony Steinhauser <asteinhauser@google.com>
Fixes: ee13cb249fab ("powerpc/64s: Add support for software count cache flush")
Cc: stable@vger.kernel.org # v4.4+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit d8f0e0b073e1ec52a05f0c2a56318b47387d2f10 upstream.
Add support for disabling the kernel implemented spectre v2 mitigation
(count cache flush on context switch) via the nospectre_v2 and
mitigations=off cmdline options.
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Christopher M. Riedl <cmr@informatik.wtf>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190524024647.381-1-cmr@informatik.wtf
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit e901378578c62202594cba0f6c076f3df365ec91 ]
Fix a bug introduced by the creation of flush_all_to_thread() for
processors that have SPE (Signal Processing Engine) and use it to
compute floating-point operations.
>From userspace perspective, the problem was seen in attempts of
computing floating-point operations which should generate exceptions.
For example:
fork();
float x = 0.0 / 0.0;
isnan(x); // forked process returns False (should be True)
The operation above also should always cause the SPEFSCR FINV bit to
be set. However, the SPE floating-point exceptions were turned off
after a fork().
Kernel versions prior to the bug used flush_spe_to_thread(), which
first saves SPEFSCR register values in tsk->thread and then calls
giveup_spe(tsk).
After commit 579e633e764e, the save_all() function was called first
to giveup_spe(), and then the SPEFSCR register values were saved in
tsk->thread. This would save the SPEFSCR register values after
disabling SPE for that thread, causing the bug described above.
Fixes 579e633e764e ("powerpc: create flush_all_to_thread()")
Signed-off-by: Felipe Rechia <felipe.rechia@datacom.com.br>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 473af09b56dc4be68e4af33220ceca6be67aa60d ]
eeh_add_to_parent_pe() sometimes removes the EEH_PE_KEEP flag, but it
incorrectly removes it from pe->type, instead of pe->state.
However, rather than clearing it from the correct field, remove it.
Inspection of the code shows that it can't ever have had any effect
(even if it had been cleared from the correct field), because the
field is never tested after it is cleared by the statement in
question.
The clear statement was added by commit 807a827d4e74 ("powerpc/eeh:
Keep PE during hotplug"), but it didn't explain why it was necessary.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit bcbe3730531239abd45ab6c6af4a18078b37dd47 ]
If a device is removed during EEH processing (either by a driver's
handler or as part of recovery), it can lead to a null dereference
in eeh_pe_report_edev().
To handle this, skip devices that have been removed.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b4d16ab58c41ff0125822464bdff074cebd0fe47 ]
In the recent commit 8b78fdb045de ("powerpc/time: Use
clockevents_register_device(), fixing an issue with large
decrementer") we changed the way we initialise the decrementer
clockevent(s).
We no longer initialise the mult & shift values of
decrementer_clockevent itself.
This has the effect of breaking PR KVM, because it uses those values
in kvmppc_emulate_dec(). The symptom is guest kernels spin forever
mid-way through boot.
For now fix it by assigning back to decrementer_clockevent the mult
and shift values.
Fixes: 8b78fdb045de ("powerpc/time: Use clockevents_register_device(), fixing an issue with large decrementer")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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decrementer
[ Upstream commit 8b78fdb045de60a4eb35460092bbd3cffa925353 ]
We currently cap the decrementer clockevent at 4 seconds, even on systems
with large decrementer support. Fix this by converting the code to use
clockevents_register_device() which calculates the upper bound based on
the max_delta passed in.
Signed-off-by: Anton Blanchard <anton@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 85a88cabad57d26d826dd94ea34d3a785824d802 ]
When performing partition migrations all present CPUs must be online
as all present CPUs must make the H_JOIN call as part of the migration
process. Once all present CPUs make the H_JOIN call, one CPU is returned
to make the rtas call to perform the migration to the destination system.
During testing of migration and changing the SMT state we have found
instances where CPUs are offlined, as part of the SMT state change,
before they make the H_JOIN call. This results in a hung system where
every CPU is either in H_JOIN or offline.
To prevent this this patch disables CPU hotplug during the migration
process.
Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>
Reviewed-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 984ecdd68de0fa1f63ce205d6c19ef5a7bc67b40 ]
The tbl pointer is being derefenced by IOMMU_PAGE_SIZE prior the check
if it is not NULL.
Just moving the dereference code to after the check, where there will
be guarantee that 'tbl' will not be NULL.
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 56d20861c027498b5a1112b4f9f05b56d906fdda ]
Call Frame Information is used by gdb for back-traces and inserting
breakpoints on function return for the "finish" command. This failed
when inside __kernel_clock_gettime. More concerning than difficulty
debugging is that CFI is also used by stack frame unwinding code to
implement exceptions. If you have an app that needs to handle
asynchronous exceptions for some reason, and you are unlucky enough to
get one inside the VDSO time functions, your app will crash.
What's wrong: There is control flow in __kernel_clock_gettime that
reaches label 99 without saving lr in r12. CFI info however is
interpreted by the unwinder without reference to control flow: It's a
simple matter of "Execute all the CFI opcodes up to the current
address". That means the unwinder thinks r12 contains the return
address at label 99. Disabuse it of that notion by resetting CFI for
the return address at label 99.
Note that the ".cfi_restore lr" could have gone anywhere from the
"mtlr r12" a few instructions earlier to the instruction at label 99.
I put the CFI as late as possible, because in general that's best
practice (and if possible grouped with other CFI in order to reduce
the number of CFI opcodes executed when unwinding). Using r12 as the
return address is perfectly fine after the "mtlr r12" since r12 on
that code path still contains the return address.
__get_datapage also has a CFI error. That function temporarily saves
lr in r0, and reflects that fact with ".cfi_register lr,r0". A later
use of r0 means the CFI at that point isn't correct, as r0 no longer
contains the return address. Fix that too.
Signed-off-by: Alan Modra <amodra@gmail.com>
Tested-by: Reza Arbab <arbab@linux.ibm.com>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 047e6575aec71d75b765c22111820c4776cd1c43 upstream.
On POWER9, under some circumstances, a broadcast TLB invalidation will
fail to invalidate the ERAT cache on some threads when there are
parallel mtpidr/mtlpidr happening on other threads of the same core.
This can cause stores to continue to go to a page after it's unmapped.
The workaround is to force an ERAT flush using PID=0 or LPID=0 tlbie
flush. This additional TLB flush will cause the ERAT cache
invalidation. Since we are using PID=0 or LPID=0, we don't get
filtered out by the TLB snoop filtering logic.
We need to still follow this up with another tlbie to take care of
store vs tlbie ordering issue explained in commit:
a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on
POWER9"). The presence of ERAT cache implies we can still get new
stores and they may miss store queue marking flush.
Cc: stable@vger.kernel.org
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190924035254.24612-3-aneesh.kumar@linux.ibm.com
[sandipan: Backported to v4.19]
Signed-off-by: Sandipan Das <sandipan@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 09ce98cacd51fcd0fa0af2f79d1e1d3192f4cbb0 upstream.
Rename the #define to indicate this is related to store vs tlbie
ordering issue. In the next patch, we will be adding another feature
flag that is used to handles ERAT flush vs tlbie ordering issue.
Fixes: a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190924035254.24612-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 677733e296b5c7a37c47da391fc70a43dc40bd67 upstream.
The store ordering vs tlbie issue mentioned in commit
a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on
POWER9") is fixed for Nimbus 2.3 and Cumulus 1.3 revisions. We don't
need to apply the fixup if we are running on them
We can only do this on PowerNV. On pseries guest with KVM we still
don't support redoing the feature fixup after migration. So we should
be enabling all the workarounds needed, because whe can possibly
migrate between DD 2.3 and DD 2.2
Fixes: a5d4b5891c2f ("powerpc/mm: Fixup tlbie vs store ordering issue on POWER9")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190924035254.24612-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b5bda6263cad9a927e1a4edb7493d542da0c1410 upstream.
schedule_work() cannot be called from MCE exception context as MCE can
interrupt even in interrupt disabled context.
Fixes: 733e4a4c4467 ("powerpc/mce: hookup memory_failure for UE errors")
Cc: stable@vger.kernel.org # v4.15+
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Acked-by: Balbir Singh <bsingharora@gmail.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820081352.8641-2-santosh@fossix.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 99ead78afd1128bfcebe7f88f3b102fb2da09aee upstream.
The current code would fail on huge pages addresses, since the shift would
be incorrect. Use the correct page shift value returned by
__find_linux_pte() to get the correct physical address. The code is more
generic and can handle both regular and compound pages.
Fixes: ba41e1e1ccb9 ("powerpc/mce: Hookup derror (load/store) UE errors")
Signed-off-by: Balbir Singh <bsingharora@gmail.com>
[arbab@linux.ibm.com: Fixup pseries_do_memory_failure()]
Signed-off-by: Reza Arbab <arbab@linux.ibm.com>
Tested-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Santosh Sivaraj <santosh@fossix.org>
Cc: stable@vger.kernel.org # v4.15+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820081352.8641-3-santosh@fossix.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit e7ca44ed3ba77fc26cf32650bb71584896662474 ]
Since commit 4388c9b3a6ee ("powerpc: Do not send system reset request
through the oops path"), pstore dmesg file is not updated when dump is
triggered from HMC. This commit modified system reset (sreset) handler
to invoke fadump or kdump (if configured), without pushing dmesg to
pstore. This leaves pstore to have old dmesg data which won't be much
of a help if kdump fails to capture the dump. This patch fixes that by
calling kmsg_dump() before heading to fadump ot kdump.
Fixes: 4388c9b3a6ee ("powerpc: Do not send system reset request through the oops path")
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190904075949.15607-1-ganeshgr@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 0b66370c61fcf5fcc1d6901013e110284da6e2bb ]
Bare metal machine checks run an "early" handler in real mode before
running the main handler which reports the event.
The main handler runs exactly as a normal interrupt handler, after the
"windup" which sets registers back as they were at interrupt entry.
CFAR does not get restored by the windup code, so that will be wrong
when the handler is run.
Restore the CFAR to the saved value before running the late handler.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802105709.27696-8-npiggin@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit aa06e3d60e245284d1e55497eb3108828092818d ]
The EEH_DEV_NO_HANDLER flag is used by the EEH system to prevent the
use of driver callbacks in drivers that have been bound part way
through the recovery process. This is necessary to prevent later stage
handlers from being called when the earlier stage handlers haven't,
which can be confusing for drivers.
However, the flag is set for all devices that are added after boot
time and only cleared at the end of the EEH recovery process. This
results in hot plugged devices erroneously having the flag set during
the first recovery after they are added (causing their driver's
handlers to be incorrectly ignored).
To remedy this, clear the flag at the beginning of recovery
processing. The flag is still cleared at the end of recovery
processing, although it is no longer really necessary.
Also clear the flag during eeh_handle_special_event(), for the same
reasons.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/b8ca5629d27de74c957d4f4b250177d1b6fc4bbd.1565930772.git.sbobroff@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit a6717c01ddc259f6f73364779df058e2c67309f8 ]
The LPAR migration implementation and userspace-initiated cpu hotplug
can interleave their executions like so:
1. Set cpu 7 offline via sysfs.
2. Begin a partition migration, whose implementation requires the OS
to ensure all present cpus are online; cpu 7 is onlined:
rtas_ibm_suspend_me -> rtas_online_cpus_mask -> cpu_up
This sets cpu 7 online in all respects except for the cpu's
corresponding struct device; dev->offline remains true.
3. Set cpu 7 online via sysfs. _cpu_up() determines that cpu 7 is
already online and returns success. The driver core (device_online)
sets dev->offline = false.
4. The migration completes and restores cpu 7 to offline state:
rtas_ibm_suspend_me -> rtas_offline_cpus_mask -> cpu_down
This leaves cpu7 in a state where the driver core considers the cpu
device online, but in all other respects it is offline and
unused. Attempts to online the cpu via sysfs appear to succeed but the
driver core actually does not pass the request to the lower-level
cpuhp support code. This makes the cpu unusable until the cpu device
is manually set offline and then online again via sysfs.
Instead of directly calling cpu_up/cpu_down, the migration code should
use the higher-level device core APIs to maintain consistent state and
serialize operations.
Fixes: 120496ac2d2d ("powerpc: Bring all threads online prior to migration/hibernation")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190802192926.19277-2-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit a8318c13e79badb92bc6640704a64cc022a6eb97 ]
When in userspace and MSR FP=0 the hardware FP state is unrelated to
the current process. This is extended for transactions where if tbegin
is run with FP=0, the hardware checkpoint FP state will also be
unrelated to the current process. Due to this, we need to ensure this
hardware checkpoint is updated with the correct state before we enable
FP for this process.
Unfortunately we get this wrong when returning to a process from a
hardware interrupt. A process that starts a transaction with FP=0 can
take an interrupt. When the kernel returns back to that process, we
change to FP=1 but with hardware checkpoint FP state not updated. If
this transaction is then rolled back, the FP registers now contain the
wrong state.
The process looks like this:
Userspace: Kernel
Start userspace
with MSR FP=0 TM=1
< -----
...
tbegin
bne
Hardware interrupt
---- >
<do_IRQ...>
....
ret_from_except
restore_math()
/* sees FP=0 */
restore_fp()
tm_active_with_fp()
/* sees FP=1 (Incorrect) */
load_fp_state()
FP = 0 -> 1
< -----
Return to userspace
with MSR TM=1 FP=1
with junk in the FP TM checkpoint
TM rollback
reads FP junk
When returning from the hardware exception, tm_active_with_fp() is
incorrectly making restore_fp() call load_fp_state() which is setting
FP=1.
The fix is to remove tm_active_with_fp().
tm_active_with_fp() is attempting to handle the case where FP state
has been changed inside a transaction. In this case the checkpointed
and transactional FP state is different and hence we must restore the
FP state (ie. we can't do lazy FP restore inside a transaction that's
used FP). It's safe to remove tm_active_with_fp() as this case is
handled by restore_tm_state(). restore_tm_state() detects if FP has
been using inside a transaction and will set load_fp and call
restore_math() to ensure the FP state (checkpoint and transaction) is
restored.
This is a data integrity problem for the current process as the FP
registers are corrupted. It's also a security problem as the FP
registers from one process may be leaked to another.
Similarly for VMX.
A simple testcase to replicate this will be posted to
tools/testing/selftests/powerpc/tm/tm-poison.c
This fixes CVE-2019-15031.
Fixes: a7771176b439 ("powerpc: Don't enable FP/Altivec if not checkpointed")
Cc: stable@vger.kernel.org # 4.15+
Signed-off-by: Gustavo Romero <gromero@linux.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190904045529.23002-2-gromero@linux.vnet.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 5c784c8414fba11b62e12439f11e109fb5751f38 ]
Currently msr_tm_active() is a wrapper around MSR_TM_ACTIVE() if
CONFIG_PPC_TRANSACTIONAL_MEM is set, or it is just a function that
returns false if CONFIG_PPC_TRANSACTIONAL_MEM is not set.
This function is not necessary, since MSR_TM_ACTIVE() just do the same and
could be used, removing the dualism and simplifying the code.
This patchset remove every instance of msr_tm_active() and replaced it
by MSR_TM_ACTIVE().
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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|
[ Upstream commit fd0944baad806dfb4c777124ec712c55b714ff51 ]
When the 'regs' field was added to struct kvm_vcpu_arch, the code
was changed to use several of the fields inside regs (e.g., gpr, lr,
etc.) but not the ccr field, because the ccr field in struct pt_regs
is 64 bits on 64-bit platforms, but the cr field in kvm_vcpu_arch is
only 32 bits. This changes the code to use the regs.ccr field
instead of cr, and changes the assembly code on 64-bit platforms to
use 64-bit loads and stores instead of 32-bit ones.
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@ozlabs.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 9c4e4c90ec24652921e31e9551fcaedc26eec86d ]
Otherwise, the following warning is encountered:
WARNING: vmlinux.o(.text+0x3dc6): Section mismatch in reference from the variable start_here_multiplatform to the function .init.text:.early_setup()
The function start_here_multiplatform() references
the function __init .early_setup().
This is often because start_here_multiplatform lacks a __init
annotation or the annotation of .early_setup is wrong.
Fixes: 56c46bba9bbf ("powerpc/64: Fix booting large kernels with STRICT_KERNEL_RWX")
Cc: Russell Currey <ruscur@russell.cc>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 8205d5d98ef7f155de211f5e2eb6ca03d95a5a60 upstream.
When we take an FP unavailable exception in a transaction we have to
account for the hardware FP TM checkpointed registers being
incorrect. In this case for this process we know the current and
checkpointed FP registers must be the same (since FP wasn't used
inside the transaction) hence in the thread_struct we copy the current
FP registers to the checkpointed ones.
This copy is done in tm_reclaim_thread(). We use thread->ckpt_regs.msr
to determine if FP was on when in userspace. thread->ckpt_regs.msr
represents the state of the MSR when exiting userspace. This is setup
by check_if_tm_restore_required().
Unfortunatley there is an optimisation in giveup_all() which returns
early if tsk->thread.regs->msr (via local variable `usermsr`) has
FP=VEC=VSX=SPE=0. This optimisation means that
check_if_tm_restore_required() is not called and hence
thread->ckpt_regs.msr is not updated and will contain an old value.
This can happen if due to load_fp=255 we start a userspace process
with MSR FP=1 and then we are context switched out. In this case
thread->ckpt_regs.msr will contain FP=1. If that same process is then
context switched in and load_fp overflows, MSR will have FP=0. If that
process now enters a transaction and does an FP instruction, the FP
unavailable will not update thread->ckpt_regs.msr (the bug) and MSR
FP=1 will be retained in thread->ckpt_regs.msr. tm_reclaim_thread()
will then not perform the required memcpy and the checkpointed FP regs
in the thread struct will contain the wrong values.
The code path for this happening is:
Userspace: Kernel
Start userspace
with MSR FP/VEC/VSX/SPE=0 TM=1
< -----
...
tbegin
bne
fp instruction
FP unavailable
---- >
fp_unavailable_tm()
tm_reclaim_current()
tm_reclaim_thread()
giveup_all()
return early since FP/VMX/VSX=0
/* ckpt MSR not updated (Incorrect) */
tm_reclaim()
/* thread_struct ckpt FP regs contain junk (OK) */
/* Sees ckpt MSR FP=1 (Incorrect) */
no memcpy() performed
/* thread_struct ckpt FP regs not fixed (Incorrect) */
tm_recheckpoint()
/* Put junk in hardware checkpoint FP regs */
....
< -----
Return to userspace
with MSR TM=1 FP=1
with junk in the FP TM checkpoint
TM rollback
reads FP junk
This is a data integrity problem for the current process as the FP
registers are corrupted. It's also a security problem as the FP
registers from one process may be leaked to another.
This patch moves up check_if_tm_restore_required() in giveup_all() to
ensure thread->ckpt_regs.msr is updated correctly.
A simple testcase to replicate this will be posted to
tools/testing/selftests/powerpc/tm/tm-poison.c
Similarly for VMX.
This fixes CVE-2019-15030.
Fixes: f48e91e87e67 ("powerpc/tm: Fix FP and VMX register corruption")
Cc: stable@vger.kernel.org # 4.12+
Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190904045529.23002-1-gromero@linux.vnet.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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|
The upstream commit:
22e9c88d486a ("powerpc/64: reuse PPC32 static inline flush_dcache_range()")
has a similar effect, but since it is a rewrite of the assembler to C, is
too invasive for stable. This patch is a minimal fix to address the issue in
assembler.
This patch applies cleanly to v5.2, v4.19 & v4.14.
When calling flush_(inval_)dcache_range with a size >4GB, we were masking
off the upper 32 bits, so we would incorrectly flush a range smaller
than intended.
This patch replaces the 32 bit shifts with 64 bit ones, so that
the full size is accounted for.
Signed-off-by: Alastair D'Silva <alastair@d-silva.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f16d80b75a096c52354c6e0a574993f3b0dfbdfe upstream.
On systems like P9 powernv where we have no TM (or P8 booted with
ppc_tm=off), userspace can construct a signal context which still has
the MSR TS bits set. The kernel tries to restore this context which
results in the following crash:
Unexpected TM Bad Thing exception at c0000000000022fc (msr 0x8000000102a03031) tm_scratch=800000020280f033
Oops: Unrecoverable exception, sig: 6 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
Modules linked in:
CPU: 0 PID: 1636 Comm: sigfuz Not tainted 5.2.0-11043-g0a8ad0ffa4 #69
NIP: c0000000000022fc LR: 00007fffb2d67e48 CTR: 0000000000000000
REGS: c00000003fffbd70 TRAP: 0700 Not tainted (5.2.0-11045-g7142b497d8)
MSR: 8000000102a03031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[E]> CR: 42004242 XER: 00000000
CFAR: c0000000000022e0 IRQMASK: 0
GPR00: 0000000000000072 00007fffb2b6e560 00007fffb2d87f00 0000000000000669
GPR04: 00007fffb2b6e728 0000000000000000 0000000000000000 00007fffb2b6f2a8
GPR08: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR12: 0000000000000000 00007fffb2b76900 0000000000000000 0000000000000000
GPR16: 00007fffb2370000 00007fffb2d84390 00007fffea3a15ac 000001000a250420
GPR20: 00007fffb2b6f260 0000000010001770 0000000000000000 0000000000000000
GPR24: 00007fffb2d843a0 00007fffea3a14a0 0000000000010000 0000000000800000
GPR28: 00007fffea3a14d8 00000000003d0f00 0000000000000000 00007fffb2b6e728
NIP [c0000000000022fc] rfi_flush_fallback+0x7c/0x80
LR [00007fffb2d67e48] 0x7fffb2d67e48
Call Trace:
Instruction dump:
e96a0220 e96a02a8 e96a0330 e96a03b8 394a0400 4200ffdc 7d2903a6 e92d0c00
e94d0c08 e96d0c10 e82d0c18 7db242a6 <4c000024> 7db243a6 7db142a6 f82d0c18
The problem is the signal code assumes TM is enabled when
CONFIG_PPC_TRANSACTIONAL_MEM is enabled. This may not be the case as
with P9 powernv or if `ppc_tm=off` is used on P8.
This means any local user can crash the system.
Fix the problem by returning a bad stack frame to the user if they try
to set the MSR TS bits with sigreturn() on systems where TM is not
supported.
Found with sigfuz kernel selftest on P9.
This fixes CVE-2019-13648.
Fixes: 2b0a576d15e0 ("powerpc: Add new transactional memory state to the signal context")
Cc: stable@vger.kernel.org # v3.9
Reported-by: Praveen Pandey <Praveen.Pandey@in.ibm.com>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190719050502.405-1-mikey@neuling.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 33439620680be5225c1b8806579a291e0d761ca0 ]
In commit 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap
space") support for using hugepages in the vmalloc and ioremap areas was
enabled for radix. Unfortunately this broke EEH MMIO error checking.
Detection works by inserting a hook which checks the results of the
ioreadXX() set of functions. When a read returns a 0xFFs response we
need to check for an error which we do by mapping the (virtual) MMIO
address back to a physical address, then mapping physical address to a
PCI device via an interval tree.
When translating virt -> phys we currently assume the ioremap space is
only populated by PAGE_SIZE mappings. If a hugepage mapping is found we
emit a WARN_ON(), but otherwise handles the check as though a normal
page was found. In pathalogical cases such as copying a buffer
containing a lot of 0xFFs from BAR memory this can result in the system
not booting because it's too busy printing WARN_ON()s.
There's no real reason to assume huge pages can't be present and we're
prefectly capable of handling them, so do that.
Fixes: 4a7b06c157a2 ("powerpc/eeh: Handle hugepages in ioremap space")
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190710150517.27114-1-oohall@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit df5be5be8735ef2ae80d5ae1f2453cd81a035c4b ]
When the firmware does PCI BAR resource allocation, it passes the assigned
addresses and flags (prefetch/64bit/...) via the "reg" property of
a PCI device device tree node so the kernel does not need to do
resource allocation.
The flags are stored in resource::flags - the lower byte stores
PCI_BASE_ADDRESS_SPACE/etc bits and the other bytes are IORESOURCE_IO/etc.
Some flags from PCI_BASE_ADDRESS_xxx and IORESOURCE_xxx are duplicated,
such as PCI_BASE_ADDRESS_MEM_PREFETCH/PCI_BASE_ADDRESS_MEM_TYPE_64/etc.
When parsing the "reg" property, we copy the prefetch flag but we skip
on PCI_BASE_ADDRESS_MEM_TYPE_64 which leaves the flags out of sync.
The missing IORESOURCE_MEM_64 flag comes into play under 2 conditions:
1. we remove PCI_PROBE_ONLY for pseries (by hacking pSeries_setup_arch()
or by passing "/chosen/linux,pci-probe-only");
2. we request resource alignment (by passing pci=resource_alignment=
via the kernel cmd line to request PAGE_SIZE alignment or defining
ppc_md.pcibios_default_alignment which returns anything but 0). Note that
the alignment requests are ignored if PCI_PROBE_ONLY is enabled.
With 1) and 2), the generic PCI code in the kernel unconditionally
decides to:
- reassign the BARs in pci_specified_resource_alignment() (works fine)
- write new BARs to the device - this fails for 64bit BARs as the generic
code looks at IORESOURCE_MEM_64 (not set) and writes only lower 32bits
of the BAR and leaves the upper 32bit unmodified which breaks BAR mapping
in the hypervisor.
This fixes the issue by copying the flag. This is useful if we want to
enforce certain BAR alignment per platform as handling subpage sized BARs
is proven to cause problems with hotplug (SLOF already aligns BARs to 64k).
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: Oliver O'Halloran <oohall@gmail.com>
Reviewed-by: Shawn Anastasio <shawn@anastas.io>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit f474c28fbcbe42faca4eb415172c07d76adcb819 upstream.
powerpc hardware triggers watchpoint before executing the instruction.
To make trigger-after-execute behavior, kernel emulates the
instruction. If the instruction is 'load something into non-volatile
register', exception handler should restore emulated register state
while returning back, otherwise there will be register state
corruption. eg, adding a watchpoint on a list can corrput the list:
# cat /proc/kallsyms | grep kthread_create_list
c00000000121c8b8 d kthread_create_list
Add watchpoint on kthread_create_list->prev:
# perf record -e mem:0xc00000000121c8c0
Run some workload such that new kthread gets invoked. eg, I just
logged out from console:
list_add corruption. next->prev should be prev (c000000001214e00), \
but was c00000000121c8b8. (next=c00000000121c8b8).
WARNING: CPU: 59 PID: 309 at lib/list_debug.c:25 __list_add_valid+0xb4/0xc0
CPU: 59 PID: 309 Comm: kworker/59:0 Kdump: loaded Not tainted 5.1.0-rc7+ #69
...
NIP __list_add_valid+0xb4/0xc0
LR __list_add_valid+0xb0/0xc0
Call Trace:
__list_add_valid+0xb0/0xc0 (unreliable)
__kthread_create_on_node+0xe0/0x260
kthread_create_on_node+0x34/0x50
create_worker+0xe8/0x260
worker_thread+0x444/0x560
kthread+0x160/0x1a0
ret_from_kernel_thread+0x5c/0x70
List corruption happened because it uses 'load into non-volatile
register' instruction:
Snippet from __kthread_create_on_node:
c000000000136be8: addis r29,r2,-19
c000000000136bec: ld r29,31424(r29)
if (!__list_add_valid(new, prev, next))
c000000000136bf0: mr r3,r30
c000000000136bf4: mr r5,r28
c000000000136bf8: mr r4,r29
c000000000136bfc: bl c00000000059a2f8 <__list_add_valid+0x8>
Register state from WARN_ON():
GPR00: c00000000059a3a0 c000007ff23afb50 c000000001344e00 0000000000000075
GPR04: 0000000000000000 0000000000000000 0000001852af8bc1 0000000000000000
GPR08: 0000000000000001 0000000000000007 0000000000000006 00000000000004aa
GPR12: 0000000000000000 c000007ffffeb080 c000000000137038 c000005ff62aaa00
GPR16: 0000000000000000 0000000000000000 c000007fffbe7600 c000007fffbe7370
GPR20: c000007fffbe7320 c000007fffbe7300 c000000001373a00 0000000000000000
GPR24: fffffffffffffef7 c00000000012e320 c000007ff23afcb0 c000000000cb8628
GPR28: c00000000121c8b8 c000000001214e00 c000007fef5b17e8 c000007fef5b17c0
Watchpoint hit at 0xc000000000136bec.
addis r29,r2,-19
=> r29 = 0xc000000001344e00 + (-19 << 16)
=> r29 = 0xc000000001214e00
ld r29,31424(r29)
=> r29 = *(0xc000000001214e00 + 31424)
=> r29 = *(0xc00000000121c8c0)
0xc00000000121c8c0 is where we placed a watchpoint and thus this
instruction was emulated by emulate_step. But because handle_dabr_fault
did not restore emulated register state, r29 still contains stale
value in above register state.
Fixes: 5aae8a5370802 ("powerpc, hw_breakpoints: Implement hw_breakpoints for 64-bit server processors")
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: stable@vger.kernel.org # 2.6.36+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 6ecb78ef56e08d2119d337ae23cb951a640dc52d upstream.
Previously, only IBAT1 and IBAT2 were used to map kernel linear mem.
Since commit 63b2bc619565 ("powerpc/mm/32s: Use BATs for
STRICT_KERNEL_RWX"), we may have all 8 BATs used for mapping
kernel text. But the suspend/restore functions only save/restore
BATs 0 to 3, and clears BATs 4 to 7.
Make suspend and restore functions respectively save and reload
the 8 BATs on CPUs having MMU_FTR_USE_HIGH_BATS feature.
Reported-by: Andreas Schwab <schwab@linux-m68k.org>
Cc: stable@vger.kernel.org
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ea84b580b95521644429cc6748b6c2bf27c8b0f3 upstream.
Instead of running with interrupts disabled, use a semaphore. This should
make it easier for backends that may need to sleep (e.g. EFI) when
performing a write:
|BUG: sleeping function called from invalid context at kernel/sched/completion.c:99
|in_atomic(): 1, irqs_disabled(): 1, pid: 2236, name: sig-xstate-bum
|Preemption disabled at:
|[<ffffffff99d60512>] pstore_dump+0x72/0x330
|CPU: 26 PID: 2236 Comm: sig-xstate-bum Tainted: G D 4.20.0-rc3 #45
|Call Trace:
| dump_stack+0x4f/0x6a
| ___might_sleep.cold.91+0xd3/0xe4
| __might_sleep+0x50/0x90
| wait_for_completion+0x32/0x130
| virt_efi_query_variable_info+0x14e/0x160
| efi_query_variable_store+0x51/0x1a0
| efivar_entry_set_safe+0xa3/0x1b0
| efi_pstore_write+0x109/0x140
| pstore_dump+0x11c/0x330
| kmsg_dump+0xa4/0xd0
| oops_exit+0x22/0x30
...
Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Fixes: 21b3ddd39fee ("efi: Don't use spinlocks for efi vars")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e9666d10a5677a494260d60d1fa0b73cc7646eb3 upstream.
Currently, CONFIG_JUMP_LABEL just means "I _want_ to use jump label".
The jump label is controlled by HAVE_JUMP_LABEL, which is defined
like this:
#if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL)
# define HAVE_JUMP_LABEL
#endif
We can improve this by testing 'asm goto' support in Kconfig, then
make JUMP_LABEL depend on CC_HAS_ASM_GOTO.
Ugly #ifdef HAVE_JUMP_LABEL will go away, and CONFIG_JUMP_LABEL will
match to the real kernel capability.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>
[nc: Fix trivial conflicts in 4.19
arch/xtensa/kernel/jump_label.c doesn't exist yet
Ensured CC_HAVE_ASM_GOTO and HAVE_JUMP_LABEL were sufficiently
eliminated]
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
Aneesh Kumar K.V
Nathan Lynch
Michael Ellerman
Christophe Leroy
Tyrel Datwyler
Michael Roth
Gustavo L. F. Walbon
Anthony Steinhauser
Vincenzo Frascino
Nathan Chancellor
Alastair D'Silva
Benjamin Herrenschmidt
Christopher M. Riedl
Felipe Rechia
Sam Bobroff
Anton Blanchard
Nathan Fontenot
Breno Leitao
Alan Modra
Santosh Sivaraj
Balbir Singh
Ganesh Goudar
Nicholas Piggin
Gustavo Romero
Paul Mackerras
Michael Neuling
Oliver O'Halloran
Alexey Kardashevskiy
Ravi Bangoria
Kees Cook
Masahiro Yamada