commit 9d72dcef89 upstream.
On PowerNV the PCIe topology is (currently) managed by the powernv platform
code in Linux in cooperation with the platform firmware. Linux's native
PCIe port service drivers operate independently of both and this can cause
problems.
The main issue is that the portbus driver will conflict with the platform
specific hotplug driver (pnv_php) over ownership of the MSI used to notify
the host when a hotplug event occurs. The portbus driver claims this MSI on
behalf of the individual port services because the same interrupt is used
for hotplug events, PMEs (on root ports), and link bandwidth change
notifications. The portbus driver will always claim the interrupt even if
the individual port service drivers, such as pciehp, are compiled out.
The second, bigger, problem is that the hotplug port service driver
fundamentally does not work on PowerNV. The platform assumes that all
PCI devices have a corresponding arch-specific handle derived from the DT
node for the device (pci_dn) and without one the platform will not allow
a PCI device to be enabled. This problem is largely due to historical
baggage, but it can't be resolved without significant re-factoring of the
platform PCI support.
We can fix these problems in the interim by setting the
"pcie_ports_disabled" flag during platform initialisation. The flag
indicates the platform owns the PCIe ports which stops the portbus driver
from being registered.
This does have the side effect of disabling all port services drivers
that is: AER, PME, BW notifications, hotplug, and DPC. However, this is
not a huge disadvantage on PowerNV since these services are either unused
or handled through other means.
Fixes: 66725152fb ("PCI/hotplug: PowerPC PowerNV PCI hotplug driver")
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191118065553.30362-1-oohall@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6da3eced8c upstream.
Recently, the spinlock implementation grew a static key optimization,
but the jump_label.h header include was left out, leading to build
errors:
linux/arch/powerpc/include/asm/spinlock.h:44:7: error: implicit declaration of function ‘static_branch_unlikely’
44 | if (!static_branch_unlikely(&shared_processor))
This commit adds the missing header.
mpe: The build break is only seen with CONFIG_JUMP_LABEL=n.
Fixes: 656c21d6af ("powerpc/shared: Use static key to detect shared processor")
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191223133147.129983-1-Jason@zx2c4.com
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 8fabc62323 ]
Some powerpc platforms (e.g. 85xx) limit DMA-able memory way below 4G.
If a system has more physical memory than this limit, the swiotlb
buffer is not addressable because it is allocated from memblock using
top-down mode.
Force memblock to bottom-up mode before calling swiotlb_init() to
ensure that the swiotlb buffer is DMA-able.
Reported-by: Christian Zigotzky <chzigotzky@xenosoft.de>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191204123524.22919-1-rppt@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3a83f677a6 ]
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: 755563bc79 ("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>
[ Upstream commit 934bda59f2 ]
While developing KASAN for 64-bit book3s, I hit the following stack
over-read.
It occurs because the hypercall to put characters onto the terminal
takes 2 longs (128 bits/16 bytes) of characters at a time, and so
hvc_put_chars() would unconditionally copy 16 bytes from the argument
buffer, regardless of supplied length. However, udbg_hvc_putc() can
call hvc_put_chars() with a single-byte buffer, leading to the error.
==================================================================
BUG: KASAN: stack-out-of-bounds in hvc_put_chars+0xdc/0x110
Read of size 8 at addr c0000000023e7a90 by task swapper/0
CPU: 0 PID: 0 Comm: swapper Not tainted 5.2.0-rc2-next-20190528-02824-g048a6ab4835b #113
Call Trace:
dump_stack+0x104/0x154 (unreliable)
print_address_description+0xa0/0x30c
__kasan_report+0x20c/0x224
kasan_report+0x18/0x30
__asan_report_load8_noabort+0x24/0x40
hvc_put_chars+0xdc/0x110
hvterm_raw_put_chars+0x9c/0x110
udbg_hvc_putc+0x154/0x200
udbg_write+0xf0/0x240
console_unlock+0x868/0xd30
register_console+0x970/0xe90
register_early_udbg_console+0xf8/0x114
setup_arch+0x108/0x790
start_kernel+0x104/0x784
start_here_common+0x1c/0x534
Memory state around the buggy address:
c0000000023e7980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0000000023e7a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1
>c0000000023e7a80: f1 f1 01 f2 f2 f2 00 00 00 00 00 00 00 00 00 00
^
c0000000023e7b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0000000023e7b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
Document that a 16-byte buffer is requred, and provide it in udbg.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a8de1304b7 ]
The DTC v1.5.1 added references to (U)INT32_MAX.
This is no problem for user-space programs since <stdint.h> defines
(U)INT32_MAX along with (u)int32_t.
For the kernel space, libfdt_env.h needs to be adjusted before we
pull in the changes.
In the kernel, we usually use s/u32 instead of (u)int32_t for the
fixed-width types.
Accordingly, we already have S/U32_MAX for their max values.
So, we should not add (U)INT32_MAX to <linux/limits.h> any more.
Instead, add them to the in-kernel libfdt_env.h to compile the
latest libfdt.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 465bfd9c44 ]
When building pseries_defconfig, building vdso32 errors out:
error: unknown target ABI 'elfv1'
This happens because -m32 in clang changes the target to 32-bit,
which does not allow the ABI to be changed.
Commit 4dc831aa88 ("powerpc: Fix compiling a BE kernel with a
powerpc64le toolchain") added these flags to fix building big endian
kernels with a little endian GCC.
Clang doesn't need -mabi because the target triple controls the
default value. -mlittle-endian and -mbig-endian manipulate the triple
into either powerpc64-* or powerpc64le-*, which properly sets the
default ABI.
Adding a debug print out in the PPC64TargetInfo constructor after line
383 above shows this:
$ echo | ./clang -E --target=powerpc64-linux -mbig-endian -o /dev/null -
Default ABI: elfv1
$ echo | ./clang -E --target=powerpc64-linux -mlittle-endian -o /dev/null -
Default ABI: elfv2
$ echo | ./clang -E --target=powerpc64le-linux -mbig-endian -o /dev/null -
Default ABI: elfv1
$ echo | ./clang -E --target=powerpc64le-linux -mlittle-endian -o /dev/null -
Default ABI: elfv2
Don't specify -mabi when building with clang to avoid the build error
with -m32 and not change any code generation.
-mcall-aixdesc is not an implemented flag in clang so it can be safely
excluded as well, see commit 238abecde8 ("powerpc: Don't use gcc
specific options on clang").
pseries_defconfig successfully builds after this patch and
powernv_defconfig and ppc44x_defconfig don't regress.
Reviewed-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
[mpe: Trim clang links in change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191119045712.39633-2-natechancellor@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4e706af3cd ]
The issue was showing "Mitigation" message via sysfs whatever the
state of "RFI Flush", but it should show "Vulnerable" when it is
disabled.
If you have "L1D private" feature enabled and not "RFI Flush" you are
vulnerable to meltdown attacks.
"RFI Flush" is the key feature to mitigate the meltdown whatever the
"L1D private" state.
SEC_FTR_L1D_THREAD_PRIV is a feature for Power9 only.
So the message should be as the truth table shows:
CPU | L1D private | RFI Flush | sysfs
----|-------------|-----------|-------------------------------------
P9 | False | False | Vulnerable
P9 | False | True | Mitigation: RFI Flush
P9 | True | False | Vulnerable: L1D private per thread
P9 | True | True | Mitigation: RFI Flush, L1D private per thread
P8 | False | False | Vulnerable
P8 | False | True | Mitigation: RFI Flush
Output before this fix:
# cat /sys/devices/system/cpu/vulnerabilities/meltdown
Mitigation: RFI Flush, L1D private per thread
# echo 0 > /sys/kernel/debug/powerpc/rfi_flush
# cat /sys/devices/system/cpu/vulnerabilities/meltdown
Mitigation: L1D private per thread
Output after fix:
# cat /sys/devices/system/cpu/vulnerabilities/meltdown
Mitigation: RFI Flush, L1D private per thread
# echo 0 > /sys/kernel/debug/powerpc/rfi_flush
# cat /sys/devices/system/cpu/vulnerabilities/meltdown
Vulnerable: L1D private per thread
Signed-off-by: Gustavo L. F. Walbon <gwalbon@linux.ibm.com>
Signed-off-by: Mauro S. M. Rodrigues <maurosr@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190502210907.42375-1-gwalbon@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7d82127474 ]
When unloading the module, one gets
------------[ cut here ]------------
Device 'cmm0' does not have a release() function, it is broken and must be fixed. See Documentation/kobject.txt.
WARNING: CPU: 0 PID: 19308 at drivers/base/core.c:1244 .device_release+0xcc/0xf0
...
We only have one static fake device. There is nothing to do when
releasing the device (via cmm_exit()).
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191031142933.10779-2-david@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 16f6b67cf0 ]
With large memory (8TB and more) hotplug, we can get soft lockup
warnings as below. These were caused by a long loop without any
explicit cond_resched which is a problem for !PREEMPT kernels.
Avoid this using cond_resched() while inserting hash page table
entries. We already do similar cond_resched() in __add_pages(), see
commit f64ac5e6e3 ("mm, memory_hotplug: add scheduling point to
__add_pages").
rcu: 3-....: (24002 ticks this GP) idle=13e/1/0x4000000000000002 softirq=722/722 fqs=12001
(t=24003 jiffies g=4285 q=2002)
NMI backtrace for cpu 3
CPU: 3 PID: 3870 Comm: ndctl Not tainted 5.3.0-197.18-default+ #2
Call Trace:
dump_stack+0xb0/0xf4 (unreliable)
nmi_cpu_backtrace+0x124/0x130
nmi_trigger_cpumask_backtrace+0x1ac/0x1f0
arch_trigger_cpumask_backtrace+0x28/0x3c
rcu_dump_cpu_stacks+0xf8/0x154
rcu_sched_clock_irq+0x878/0xb40
update_process_times+0x48/0x90
tick_sched_handle.isra.16+0x4c/0x80
tick_sched_timer+0x68/0xe0
__hrtimer_run_queues+0x180/0x430
hrtimer_interrupt+0x110/0x300
timer_interrupt+0x108/0x2f0
decrementer_common+0x114/0x120
--- interrupt: 901 at arch_add_memory+0xc0/0x130
LR = arch_add_memory+0x74/0x130
memremap_pages+0x494/0x650
devm_memremap_pages+0x3c/0xa0
pmem_attach_disk+0x188/0x750
nvdimm_bus_probe+0xac/0x2c0
really_probe+0x148/0x570
driver_probe_device+0x19c/0x1d0
device_driver_attach+0xcc/0x100
bind_store+0x134/0x1c0
drv_attr_store+0x44/0x60
sysfs_kf_write+0x64/0x90
kernfs_fop_write+0x1a0/0x270
__vfs_write+0x3c/0x70
vfs_write+0xd0/0x260
ksys_write+0xdc/0x130
system_call+0x5c/0x68
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/20191001084656.31277-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8e6b6da91a ]
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>
[ Upstream commit e44ff9ea8f ]
Some of our scripts are passed $objdump and then call it as
"$objdump". This doesn't work if it contains spaces because we're
using ccache, for example you get errors such as:
./arch/powerpc/tools/relocs_check.sh: line 48: ccache ppc64le-objdump: No such file or directory
./arch/powerpc/tools/unrel_branch_check.sh: line 26: ccache ppc64le-objdump: No such file or directory
Fix it by not quoting the string when we expand it, allowing the shell
to do the right thing for us.
Fixes: a71aa05e14 ("powerpc: Convert relocs_check to a shell script using grep")
Fixes: 4ea80652dc ("powerpc/64s: Tool to flag direct branches from unrelocated interrupt vectors")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191024004730.32135-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 75838a3290 ]
If the hypervisor returned H_PTEG_FULL for H_ENTER hcall, retry a hash page table
insert by removing a random entry from the group.
After some runtime, it is very well possible to find all the 8 hash page table
entry slot in the hpte group used for mapping. Don't fail a bolted entry insert
in that case. With Storage class memory a user can find this error easily since
a namespace enable/disable is equivalent to memory add/remove.
This results in failures as reported below:
$ ndctl create-namespace -r region1 -t pmem -m devdax -a 65536 -s 100M
libndctl: ndctl_dax_enable: dax1.3: failed to enable
Error: namespace1.2: failed to enable
failed to create namespace: No such device or address
In kernel log we find the details as below:
Unable to create mapping for hot added memory 0xc000042006000000..0xc00004200d000000: -1
dax_pmem: probe of dax1.3 failed with error -14
This indicates that we failed to create a bolted hash table entry for direct-map
address backing the namespace.
We also observe failures such that not all namespaces will be enabled with
ndctl enable-namespace all command.
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/20191024093542.29777-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit eb8e20f890 ]
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>
[ Upstream commit c9029ef9c9 ]
Commit aea447141c ("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>
commit b67a95f2ab upstream.
The PCI INTx interrupts and other LSI interrupts are handled differently
under a sPAPR platform. When the interrupt source characteristics are
queried, the hypervisor returns an H_INT_ESB flag to inform the OS
that it should be using the H_INT_ESB hcall for interrupt management
and not loads and stores on the interrupt ESB pages.
A default -1 value is returned for the addresses of the ESB pages. The
driver ignores this condition today and performs a bogus IO mapping.
Recent changes and the DEBUG_VM configuration option make the bug
visible with :
kernel BUG at arch/powerpc/include/asm/book3s/64/pgtable.h:612!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Radix MMU=Hash SMP NR_CPUS=1024 NUMA pSeries
Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.0-0.rc6.git0.1.fc32.ppc64le #1
NIP: c000000000f63294 LR: c000000000f62e44 CTR: 0000000000000000
REGS: c0000000fa45f0d0 TRAP: 0700 Not tainted (5.4.0-0.rc6.git0.1.fc32.ppc64le)
...
NIP ioremap_page_range+0x4c4/0x6e0
LR ioremap_page_range+0x74/0x6e0
Call Trace:
ioremap_page_range+0x74/0x6e0 (unreliable)
do_ioremap+0x8c/0x120
__ioremap_caller+0x128/0x140
ioremap+0x30/0x50
xive_spapr_populate_irq_data+0x170/0x260
xive_irq_domain_map+0x8c/0x170
irq_domain_associate+0xb4/0x2d0
irq_create_mapping+0x1e0/0x3b0
irq_create_fwspec_mapping+0x27c/0x3e0
irq_create_of_mapping+0x98/0xb0
of_irq_parse_and_map_pci+0x168/0x230
pcibios_setup_device+0x88/0x250
pcibios_setup_bus_devices+0x54/0x100
__of_scan_bus+0x160/0x310
pcibios_scan_phb+0x330/0x390
pcibios_init+0x8c/0x128
do_one_initcall+0x60/0x2c0
kernel_init_freeable+0x290/0x378
kernel_init+0x2c/0x148
ret_from_kernel_thread+0x5c/0x80
Fixes: bed81ee181 ("powerpc/xive: introduce H_INT_ESB hcall")
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Tested-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191203163642.2428-1-clg@kaod.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1ca3dec2b2 upstream.
When the machine crash handler is invoked, all interrupts are masked
but interrupts which have not been started yet do not have an ESB page
mapped in the Linux address space. This crashes the 'crash kexec'
sequence on sPAPR guests.
To fix, force the mapping of the ESB page when an interrupt is being
mapped in the Linux IRQ number space. This is done by setting the
initial state of the interrupt to OFF which is not necessarily the
case on PowerNV.
Fixes: 243e25112d ("powerpc/xive: Native exploitation of the XIVE interrupt controller")
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Greg Kurz <groug@kaod.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191031063100.3864-1-clg@kaod.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit b682c86924 ]
The add_ssaaaa, sub_ddmmss, umul_ppmm and udiv_qrnnd macros originate
from GCC's longlong.h which in turn was copied from GMP's longlong.h a
few decades ago.
This was found when compiling with clang:
arch/powerpc/math-emu/fnmsub.c:46:2: error: invalid use of a cast in a
inline asm context requiring an l-value: remove the cast or build with
-fheinous-gnu-extensions
FP_ADD_D(R, T, B);
^~~~~~~~~~~~~~~~~
...
./arch/powerpc/include/asm/sfp-machine.h:283:27: note: expanded from
macro 'sub_ddmmss'
: "=r" ((USItype)(sh)), \
~~~~~~~~~~^~~
Segher points out: this was fixed in GCC over 16 years ago
( https://gcc.gnu.org/r56600 ), and in GMP (where it comes from)
presumably before that.
Update the add_ssaaaa, sub_ddmmss, umul_ppmm and udiv_qrnnd macros to
the latest GCC version in order to git rid of the invalid casts. These
were taken as-is from GCC's longlong in order to make future syncs
obvious. Other parts of sfp-machine.h were left as-is as the file
contains more features than present in longlong.h.
Link: https://github.com/ClangBuiltLinux/linux/issues/260
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit efa9ace68e ]
In dlpar_parse_cc_property(), 'prop->name' is allocated by kstrdup().
kstrdup() may return NULL, so it should be checked and handle error.
And prop should be freed if 'prop->name' is NULL.
Signed-off-by: Gen Zhang <blackgod016574@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 505a314fb2 ]
HMIs will crash the kernel due to
BRANCH_LINK_TO_FAR(hmi_exception_realmode)
Calling into the OPD instead of the actual code.
Fixes: 2337d20728 ("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>
[ Upstream commit 47918bc68b ]
In update_lmb_associativity_index() we lookup dr_node using
of_find_node_by_path() which takes a reference for us. In the
non-error case we forget to drop the reference. Note that
find_aa_index() does modify properties of the node, but doesn't need
an extra reference held once it's returned.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0deae39cec ]
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>
[ Upstream commit c20577014f ]
The current implementation of the OPAL_PCI_EEH_FREEZE_STATUS call in
skiboot's NPU driver does not touch the pci_error_type parameter so
it might have garbage but the powernv code analyzes it nevertheless.
This initializes pcierr and fstate to zero in all call sites.
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3cfb9ebe90 ]
The bamboo dts has a bug: it uses a non-naturally aligned range
for PCI memory space. This isnt' supported by the code, thus
causing PCI to break on this system.
This is due to the fact that while the chip memory map has 1G
reserved for PCI memory, it's only 512M aligned. The code doesn't
know how to split that into 2 different PMMs and fails, so limit
the region to 512M.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 49a502ea23 ]
As several other arches including x86, this patch makes it explicit
that a bad page fault is a NULL pointer dereference when the fault
address is lower than PAGE_SIZE
In the mean time, this page makes all bad_page_fault() messages
shorter so that they remain on one single line. And it prefixes them
by "BUG: " so that they get easily grepped.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Avoid pr_cont()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b18f0ae92b ]
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>
[ Upstream commit 72e7bcc2cd ]
When building for ppc32 with clang these flags are unsupported:
-ffixed-r2 and -mmultiple
llvm's lib/Target/PowerPC/PPCRegisterInfo.cpp marks r2 as reserved on
when building for SVR4ABI and !ppc64:
// The SVR4 ABI reserves r2 and r13
if (Subtarget.isSVR4ABI()) {
// We only reserve r2 if we need to use the TOC pointer. If we have no
// explicit uses of the TOC pointer (meaning we're a leaf function with
// no constant-pool loads, etc.) and we have no potential uses inside an
// inline asm block, then we can treat r2 has an ordinary callee-saved
// register.
const PPCFunctionInfo *FuncInfo = MF.getInfo<PPCFunctionInfo>();
if (!TM.isPPC64() || FuncInfo->usesTOCBasePtr() || MF.hasInlineAsm())
markSuperRegs(Reserved, PPC::R2); // System-reserved register
markSuperRegs(Reserved, PPC::R13); // Small Data Area pointer register
}
This means we can safely omit -ffixed-r2 when building for 32-bit
targets.
The -mmultiple/-mno-multiple flags are not supported by clang, so
platforms that might support multiple miss out on using multiple word
instructions.
We wrap these flags in cc-option so that when Clang gains support the
kernel will be able use these flags.
Clang 8 can then build a ppc44x_defconfig which boots in Qemu:
make CC=clang-8 ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnu- ppc44x_defconfig
./scripts/config -e CONFIG_DEVTMPFS -d DEVTMPFS_MOUNT
make CC=clang-8 ARCH=powerpc CROSS_COMPILE=powerpc-linux-gnu-
qemu-system-ppc -M bamboo \
-kernel arch/powerpc/boot/zImage \
-dtb arch/powerpc/boot/dts/bamboo.dtb \
-initrd ~/ppc32-440-rootfs.cpio \
-nographic -serial stdio -monitor pty -append "console=ttyS0"
Link: https://github.com/ClangBuiltLinux/linux/issues/261
Link: https://bugs.llvm.org/show_bug.cgi?id=39556
Link: https://bugs.llvm.org/show_bug.cgi?id=39555
Signed-off-by: Joel Stanley <joel@jms.id.au>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2d46d4877b ]
Raw event code has couple of fields "unit" and "cache" in it, to capture
the "unit" to monitor for a given pmcxsel and cache reload qualifier to
program in MMCR1.
isa207_get_constraint() refers "unit" field to update the MMCRC (L2/L3)
Event bus control fields with "cache" bits of the raw event code.
These are power8 specific and not supported by PowerISA v3.0 pmu. So wrap
the checks to be power8 specific. Also, "cache" bit field is referred to
update MMCR1[16:17] and this check can be power8 specific.
Fixes: 7ffd948fae ('powerpc/perf: factor out power8 pmu functions')
Signed-off-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e93ba1b7eb ]
This patch fixes the loop in p_block_mapped() and v_block_mapped()
to scan the entire bat_addrs[] array.
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>
[ Upstream commit 7de0869093 ]
We have seen many crashes on powerpc hosts while loading bpf programs.
The problem here is that bpf_int_jit_compile() does a first pass
to compute the program length.
Then it allocates memory to store the generated program and
calls bpf_jit_build_body() a second time (and a third time
later)
What I have observed is that the second bpf_jit_build_body()
could end up using few more words than expected.
If bpf_jit_binary_alloc() put the space for the program
at the end of the allocated page, we then write on
a non mapped memory.
It appears that bpf_jit_emit_tail_call() calls
bpf_jit_emit_common_epilogue() while ctx->seen might not
be stable.
Only after the second pass we can be sure ctx->seen wont be changed.
Trying to avoid a second pass seems quite complex and probably
not worth it.
Fixes: ce0761419f ("powerpc/bpf: Implement support for tail calls")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Sandipan Das <sandipan@linux.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191101033444.143741-1-edumazet@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit af2e8c68b9 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>
commit 39e72bf96f upstream.
In commit ee13cb249f ("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: ee13cb249f ("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>
[ Upstream commit 9c87156cce ]
When building with clang (8 trunk, 7.0 release) the frame size limit is
hit:
arch/powerpc/xmon/xmon.c:452:12: warning: stack frame size of 2576
bytes in function 'xmon_core' [-Wframe-larger-than=]
Some investigation by Naveen indicates this is due to clang saving the
addresses to printf format strings on the stack.
While this issue is investigated, bump up the frame size limit for xmon
when building with clang.
Link: https://github.com/ClangBuiltLinux/linux/issues/252
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e901378578 ]
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 579e633e76, 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 579e633e76 ("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>
[ Upstream commit 81d1b54dec ]
When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the
linear mapping at the text/data boundary so we can map the kernel
text read only.
Currently we always use a small page at the text/data boundary, even
when that's not necessary:
Mapped 0x0000000000000000-0x0000000000e00000 with 2.00 MiB pages
Mapped 0x0000000000e00000-0x0000000001000000 with 64.0 KiB pages
Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
This is because the check that the mapping crosses the __init_begin
boundary is too strict, it also returns true when we map exactly up to
the boundary.
So fix it to check that the mapping would actually map past
__init_begin, and with that we see:
Mapped 0x0000000000000000-0x0000000040000000 with 2.00 MiB pages
Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3b5657ed5b ]
When we have CONFIG_STRICT_KERNEL_RWX enabled, we want to split the
linear mapping at the text/data boundary so we can map the kernel text
read only.
But the current logic uses small pages for the entire text section,
regardless of whether a larger page size would fit. eg. with the
boundary at 16M we could use 2M pages, but instead we use 64K pages up
to the 16M boundary:
Mapped 0x0000000000000000-0x0000000001000000 with 64.0 KiB pages
Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
This is because the test is checking if addr is < __init_begin
and addr + mapping_size is >= _stext. But that is true for all pages
between _stext and __init_begin.
Instead what we want to check is if we are crossing the text/data
boundary, which is at __init_begin. With that fixed we see:
Mapped 0x0000000000000000-0x0000000000e00000 with 2.00 MiB pages
Mapped 0x0000000000e00000-0x0000000001000000 with 64.0 KiB pages
Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
ie. we're correctly using 2MB pages below __init_begin, but we still
drop down to 64K pages unnecessarily at the boundary.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5c6499b704 ]
When we have CONFIG_STRICT_KERNEL_RWX enabled, we try to split the
kernel linear (1:1) mapping so that the kernel text is in a separate
page to kernel data, so we can mark the former read-only.
We could achieve that just by always using 64K pages for the linear
mapping, but we try to be smarter. Instead we use huge pages when
possible, and only switch to smaller pages when necessary.
However we have an off-by-one bug in that logic, which causes us to
calculate the wrong boundary between text and data.
For example with the end of the kernel text at 16M we see:
radix-mmu: Mapped 0x0000000000000000-0x0000000001200000 with 64.0 KiB pages
radix-mmu: Mapped 0x0000000001200000-0x0000000040000000 with 2.00 MiB pages
radix-mmu: Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
ie. we mapped from 0 to 18M with 64K pages, even though the boundary
between text and data is at 16M.
With the fix we see we're correctly hitting the 16M boundary:
radix-mmu: Mapped 0x0000000000000000-0x0000000001000000 with 64.0 KiB pages
radix-mmu: Mapped 0x0000000001000000-0x0000000040000000 with 2.00 MiB pages
radix-mmu: Mapped 0x0000000040000000-0x0000000100000000 with 1.00 GiB pages
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c6c26fb55e ]
This patch exports the raw per-CPU VPA data via debugfs.
A per-CPU file is created which exports the VPA data of
that CPU to help debug some of the VPA related issues or
to analyze the per-CPU VPA related statistics.
v3: Removed offline CPU check.
v2: Included offline CPU check and other review comments.
Signed-off-by: Aravinda Prasad <aravinda@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
