Rather than pass in the soft-masking and KVM tests via macro that is
passed to another macro to expand it, switch to usig gas macros and
conditionally expand the soft-masking and KVM tests.
The system reset with its idle test is open coded as it is a one-off.
No generated code change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The sreset handler KVM test theoretically should not depend on P7.
In practice KVM now only supports P7 and up so no real bug fix, but
this change is made now so the quirk is not propagated through
cleanup patches.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
- Re-name the macros to _REAL and _VIRT suffixes rather than no and
_RELON suffix.
- Move the macro definitions together in the file.
- Move RELOCATABLE ifdef inside the _VIRT macro.
Further consolidation between variants does not buy much here.
No generated code change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Switch to a gas macro that conditionally expands the RI clearing
instruction.
No generated code change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Replace all instances of this with gas macros that test the hsrr
parameter and use the appropriate register names / labels.
No generated code change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Remove extraneous 2nd check for 0xea0 in SOFTEN_TEST]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Remove SOFTEN_VALUE_0x980, it's been unused since commit
dabe859ec6 ("powerpc: Give hypervisor decrementer interrupts their
own handler") (Sep 2012).
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
By convention, all lines should be separated by a semicolons. Last line
should have neither semicolon or line wrap.
No generated code change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
These two function have never been used anywhere in the kernel tree
since they were added to the kernel.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
None of these routines were ever used anywhere in the kernel tree
since they were added to the kernel.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
These have been unused anywhere in the kernel tree ever since they've
been added to the kernel.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This function has never been used anywhere in the kernel tree since it
was added to the tree. We also now have proper PCIe P2P APIs in the core
kernel, and any new P2P support should be using those.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Commit ed49f7fd64 ("powerpc/xmon: Disable tracing when entering
xmon") added code to disable recording trace entries while in xmon. The
commit introduced a variable 'tracing_enabled' to record if tracing was
enabled on xmon entry, and used this to conditionally enable tracing
during exit from xmon.
However, we are not checking the value of 'fromipi' variable in
xmon_core() when setting 'tracing_enabled'. Due to this, when secondary
cpus enter xmon, they will see tracing as being disabled already and
tracing won't be re-enabled on exit. Fix the same.
Fixes: ed49f7fd64 ("powerpc/xmon: Disable tracing when entering xmon")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The guard macro __PPC_ASM_H in the header ppc_asm.h
doesn't match the #ifndef macro _PPC_ASM_H. The patch
makes them the same.
Signed-off-by: Denis Efremov <efremov@linux.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The powerpc's flush_cache_vmap() is defined as a macro and never use
both of its arguments, so it will generate a compilation warning,
lib/ioremap.c: In function 'ioremap_page_range':
lib/ioremap.c:203:16: warning: variable 'start' set but not used
[-Wunused-but-set-variable]
Fix it by making it an inline function.
Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The opening comment mark "/**" is reserved for kernel-doc comments, so
it will generate a warning with "make W=1".
arch/powerpc/kernel/eeh_cache.c:37: warning: cannot understand function
prototype: 'struct pci_io_addr_range
Since this is not a kernel-doc for the struct below, but rather an
overview of this source eeh_cache.c, just use the free-form comments
kernel-doc syntax instead.
Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Selects HAVE_C_RECORDMCOUNT to use the C version of the recordmcount
intead of the old Perl Version of recordmcount.
This should improve build time. It also seems like the old Perl Version
misses some calls to _mcount that the C version finds.
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
An impending change to enable HAVE_C_RECORDMCOUNT on powerpc leads to
warnings such as the following:
# modprobe kprobe_example
ftrace-powerpc: Not expected bl: opcode is 3c4c0001
WARNING: CPU: 0 PID: 227 at kernel/trace/ftrace.c:2001 ftrace_bug+0x90/0x318
Modules linked in:
CPU: 0 PID: 227 Comm: modprobe Not tainted 5.2.0-rc6-00678-g1c329100b942 #2
NIP: c000000000264318 LR: c00000000025d694 CTR: c000000000f5cd30
REGS: c000000001f2b7b0 TRAP: 0700 Not tainted (5.2.0-rc6-00678-g1c329100b942)
MSR: 900000010282b033 <SF,HV,VEC,VSX,EE,FP,ME,IR,DR,RI,LE,TM[E]> CR: 28228222 XER: 00000000
CFAR: c0000000002642fc IRQMASK: 0
<snip>
NIP [c000000000264318] ftrace_bug+0x90/0x318
LR [c00000000025d694] ftrace_process_locs+0x4f4/0x5e0
Call Trace:
[c000000001f2ba40] [0000000000000004] 0x4 (unreliable)
[c000000001f2bad0] [c00000000025d694] ftrace_process_locs+0x4f4/0x5e0
[c000000001f2bb90] [c00000000020ff10] load_module+0x25b0/0x30c0
[c000000001f2bd00] [c000000000210cb0] sys_finit_module+0xc0/0x130
[c000000001f2be20] [c00000000000bda4] system_call+0x5c/0x70
Instruction dump:
419e0018 2f83ffff 419e00bc 2f83ffea 409e00cc 4800001c 0fe00000 3c62ff96
39000001 39400000 386386d0 480000c4 <0fe00000> 3ce20003 39000001 3c62ff96
---[ end trace 4c438d5cebf78381 ]---
ftrace failed to modify
[<c0080000012a0008>] 0xc0080000012a0008
actual: 01:00:4c:3c
Initializing ftrace call sites
ftrace record flags: 2000000
(0)
expected tramp: c00000000006af4c
Looking at the relocation records in __mcount_loc shows a few spurious
entries:
RELOCATION RECORDS FOR [__mcount_loc]:
OFFSET TYPE VALUE
0000000000000000 R_PPC64_ADDR64 .text.unlikely+0x0000000000000008
0000000000000008 R_PPC64_ADDR64 .text.unlikely+0x0000000000000014
0000000000000010 R_PPC64_ADDR64 .text.unlikely+0x0000000000000060
0000000000000018 R_PPC64_ADDR64 .text.unlikely+0x00000000000000b4
0000000000000020 R_PPC64_ADDR64 .init.text+0x0000000000000008
0000000000000028 R_PPC64_ADDR64 .init.text+0x0000000000000014
The first entry in each section is incorrect. Looking at the
relocation records, the spurious entries correspond to the
R_PPC64_ENTRY records:
RELOCATION RECORDS FOR [.text.unlikely]:
OFFSET TYPE VALUE
0000000000000000 R_PPC64_REL64 .TOC.-0x0000000000000008
0000000000000008 R_PPC64_ENTRY *ABS*
0000000000000014 R_PPC64_REL24 _mcount
<snip>
The problem is that we are not validating the return value from
get_mcountsym() in sift_rel_mcount(). With this entry, mcountsym is 0,
but Elf_r_sym(relp) also ends up being 0. Fix this by ensuring
mcountsym is valid before processing the entry.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Tested-by: Satheesh Rajendran <sathnaga@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The protocol for suspending or migrating an LPAR requires all present
processor threads to enter H_JOIN. So if we have threads offline, we
have to temporarily bring them up. This can race with administrator
actions such as SMT state changes. As of dfd718a2ed ("powerpc/rtas:
Fix a potential race between CPU-Offline & Migration"),
rtas_ibm_suspend_me() accounts for this, but errors out with -EBUSY
for what almost certainly is a transient condition in any reasonable
scenario.
Callers of rtas_ibm_suspend_me() already retry when -EAGAIN is
returned, and it is typical during a migration for that to happen
repeatedly for several minutes polling the H_VASI_STATE hcall result
before proceeding to the next stage.
So return -EAGAIN instead of -EBUSY when this race is
encountered. Additionally: logging this event is still appropriate but
use pr_info instead of pr_err; and remove use of unlikely() while here
as this is not a hot path at all.
Fixes: dfd718a2ed ("powerpc/rtas: Fix a potential race between CPU-Offline & Migration")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
commit 243e25112d ("powerpc/xive: Native exploitation of the XIVE
interrupt controller") added an option to turn off Linux native XIVE
usage via the xive=off kernel command line option.
This documents this option.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Stewart Smith <stewart@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Merge our fixes branch into next, this brings in a number of commits
that fix bugs we don't want to hit in next, in particular the fix for
CVE-2019-12817.
One fix for a bug in our context id handling on 64-bit hash CPUs, which can lead
to unrelated processes being able to read/write to each other's virtual memory.
See the commit for full details.
That is the fix for CVE-2019-12817.
This also adds a kernel selftest for the bug.
-----BEGIN PGP SIGNATURE-----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=y5oH
-----END PGP SIGNATURE-----
Merge tag 'powerpc-5.2-6' into fixes
This merges the commits that were the fix for CVE-2019-12817, which was
developed under embargo. They have already been merged by Linus
Merge them into fixes now so that this branch contains all the fixes for
this release.
The early machine check runs in real mode, so locking is unnecessary.
Worse, the windup does not restore AMR, so this can result in a false
KUAP fault after a recoverable machine check hits inside a user copy
operation.
Fix this similarly to HMI by just avoiding the kuap lock in the
early machine check handler (it will be set by the late handler that
runs in virtual mode if that runs). If the virtual mode handler is
reached, it will lock and restore the AMR.
Fixes: 890274c2dc ("powerpc/64s: Implement KUAP for Radix MMU")
Cc: Russell Currey <ruscur@russell.cc>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
If we enter an L1 guest with a pending decrementer exception then this
is cleared on guest exit if the guest has writtien a positive value
into the decrementer (indicating that it handled the decrementer
exception) since there is no other way to detect that the guest has
handled the pending exception and that it should be dequeued. In the
event that the L1 guest tries to run a nested (L2) guest immediately
after this and the L2 guest decrementer is negative (which is loaded
by L1 before making the H_ENTER_NESTED hcall), then the pending
decrementer exception isn't cleared and the L2 entry is blocked since
L1 has a pending exception, even though L1 may have already handled
the exception and written a positive value for it's decrementer. This
results in a loop of L1 trying to enter the L2 guest and L0 blocking
the entry since L1 has an interrupt pending with the outcome being
that L2 never gets to run and hangs.
Fix this by clearing any pending decrementer exceptions when L1 makes
the H_ENTER_NESTED hcall since it won't do this if it's decrementer
has gone negative, and anyway it's decrementer has been communicated
to L0 in the hdec_expires field and L0 will return control to L1 when
this goes negative by delivering an H_DECREMENTER exception.
Fixes: 95a6432ce9 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
On POWER9 the decrementer can operate in large decrementer mode where
the decrementer is 56 bits and signed extended to 64 bits. When not
operating in this mode the decrementer behaves as a 32 bit decrementer
which is NOT signed extended (as on POWER8).
Currently when reading a guest decrementer value we don't take into
account whether the large decrementer is enabled or not, and this
means the value will be incorrect when the guest is not using the
large decrementer. Fix this by sign extending the value read when the
guest isn't using the large decrementer.
Fixes: 95a6432ce9 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
When a guest vcpu moves from one physical thread to another it is
necessary for the host to perform a tlb flush on the previous core if
another vcpu from the same guest is going to run there. This is because the
guest may use the local form of the tlb invalidation instruction meaning
stale tlb entries would persist where it previously ran. This is handled
on guest entry in kvmppc_check_need_tlb_flush() which calls
flush_guest_tlb() to perform the tlb flush.
Previously the generic radix__local_flush_tlb_lpid_guest() function was
used, however the functionality was reimplemented in flush_guest_tlb()
to avoid the trace_tlbie() call as the flushing may be done in real
mode. The reimplementation in flush_guest_tlb() was missing an erat
invalidation after flushing the tlb.
This lead to observable memory corruption in the guest due to the
caching of stale translations. Fix this by adding the erat invalidation.
Fixes: 70ea13f6e6 ("KVM: PPC: Book3S HV: Flush TLB on secondary radix threads")
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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>
With the strict dma mask checking introduced with the switch to
the generic DMA direct code common wifi chips on 32-bit powerbooks
stopped working. Add a 30-bit ZONE_DMA to the 32-bit pmac builds
to allow them to reliably allocate dma coherent memory.
Fixes: 65a21b71f9 ("powerpc/dma: remove dma_nommu_dma_supported")
Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This sets the HAVE_ARCH_HUGE_VMAP option, and defines the required
page table functions.
This enables huge (2MB and 1GB) ioremap mappings. I don't have a
benchmark for this change, but huge vmap will be used by a later core
kernel change to enable huge vmalloc memory mappings. This improves
cached `git diff` performance by about 5% on a 2-node POWER9 with 32MB
size dentry cache hash.
Profiling git diff dTLB misses with a vanilla kernel:
81.75% git [kernel.vmlinux] [k] __d_lookup_rcu
7.21% git [kernel.vmlinux] [k] strncpy_from_user
1.77% git [kernel.vmlinux] [k] find_get_entry
1.59% git [kernel.vmlinux] [k] kmem_cache_free
40,168 dTLB-miss
0.100342754 seconds time elapsed
With powerpc huge vmalloc:
2,987 dTLB-miss
0.095933138 seconds time elapsed
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Radix can use ioremap_page_range for ioremap, after slab is available.
This makes it possible to enable huge ioremap mapping support.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
__ioremap_at error handling is wonky, it requires caller to clean up
after it. Implement a helper that does the map and error cleanup and
remove the requirement from the caller.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Nest and core IMC (In-Memory Collection counters) assigns a particular
cpu as the designated target for counter data collection. During
system boot, the first online cpu in a chip gets assigned as the
designated cpu for that chip(for nest-imc) and the first online cpu in
a core gets assigned as the designated cpu for that core(for
core-imc).
If the designated cpu goes offline, the next online cpu from the same
chip(for nest-imc)/core(for core-imc) is assigned as the next target,
and the event context is migrated to the target cpu. Currently,
cpumask_any_but() function is used to find the target cpu. Though this
function is expected to return a `random` cpu, this always returns the
next online cpu.
If all cpus in a chip/core is offlined in a sequential manner,
starting from the first cpu, the event migration has to happen for all
the cpus which goes offline. Since the migration process involves a
grace period, the total time taken to offline all the cpus will be
significantly high.
Example:
In a system which has 2 sockets, with
NUMA node0 CPU(s): 0-87
NUMA node8 CPU(s): 88-175
Time taken to offline cpu 88-175:
real 2m56.099s
user 0m0.191s
sys 0m0.000s
Use cpumask_last() to choose the target cpu, when the designated cpu
goes online, so the migration will happen only when the last_cpu in
the mask goes offline. This way the time taken to offline all cpus in
a chip/core can be reduced.
With the patch:
Time taken to offline cpu 88-175:
real 0m12.207s
user 0m0.171s
sys 0m0.000s
Offlining all cpus in reverse order is also taken care because,
cpumask_any_but() is used to find the designated cpu if the last cpu
in the mask goes offline. Since cpumask_any_but() always return the
first cpu in the mask, that becomes the designated cpu and migration
will happen only when the first_cpu in the mask goes offline.
Example: With the patch,
Time taken to offline cpu from 175-88:
real 0m9.330s
user 0m0.110s
sys 0m0.000s
Signed-off-by: Anju T Sudhakar <anju@linux.vnet.ibm.com>
Reviewed-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
pr_info shows SPR and timebase as a decimal value with a '0x'
prefix, which is somewhat misleading.
Fix it to print hexadecimal, as was intended.
Fixes: 10d91611f4 ("powerpc/64s: Reimplement book3s idle code in C")
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
A couple of bugs in queue_hotplug_event():
1. Unchecked kmalloc result which could lead to an oops.
2. Use of GFP_KERNEL allocations in interrupt context (this code's
only caller is ras_hotplug_interrupt()).
Use kmemdup to avoid open-coding the allocation+copy and check for
failure; use GFP_ATOMIC for both allocations.
Ultimately it probably would be better to avoid or reduce allocations
in this path if possible.
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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: 5aae8a5370 ("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>
When calling debugfs functions, there is no need to ever check the
return value. The function can work or not, but the code logic should
never do something different based on this.
Because there's no need to check, also make the return value of the
local debugfs_create_io_x64() call void, as no one ever did anything
with the return value (as they did not need to.)
And make the cxl_debugfs_* calls return void as no one was even checking
their return value at all.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Flexible array members should be denoted using [] instead of [0], else
gcc will not warn when they are no longer at the end of the structure.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Move a misplaced paren that makes the condition always true.
Fixes: 63b2bc6195 ("powerpc/mm/32s: Use BATs for STRICT_KERNEL_RWX")
Cc: stable@vger.kernel.org # v5.1+
Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Previously, only IBAT1 and IBAT2 were used to map kernel linear mem.
Since commit 63b2bc6195 ("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>
In some cases, compiler can allocate the same register for operand 'res'
and 'vecoutptr', resulting in segfault at 'stxvd2x 40,0,%[vecoutptr]'
because base register will contain 1, yielding a false-positive.
This is because output 'res' must be marked as an earlyclobber operand so
it may not overlap an input operand ('vecoutptr').
Signed-off-by: Gustavo Romero <gromero@linux.vnet.ibm.com>
Reviewed-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The hcall H_SET_DAWR is used by a guest to set the data address
watchpoint register (DAWR). This hcall is handled in the host in
kvmppc_h_set_dawr() which can be called in either real mode on the
guest exit path from hcall_try_real_mode() in book3s_hv_rmhandlers.S,
or in virtual mode when called from kvmppc_pseries_do_hcall() in
book3s_hv.c.
The function kvmppc_h_set_dawr() updates the dawr and dawrx fields in
the vcpu struct accordingly and then also writes the respective values
into the DAWR and DAWRX registers directly. It is necessary to write
the registers directly here when calling the function in real mode
since the path to re-enter the guest won't do this. However when in
virtual mode the host DAWR and DAWRX values have already been
restored, and so writing the registers would overwrite these.
Additionally there is no reason to write the guest values here as
these will be read from the vcpu struct and written to the registers
appropriately the next time the vcpu is run.
This also avoids the case when handling h_set_dawr for a nested guest
where the guest hypervisor isn't able to write the DAWR and DAWRX
registers directly and must rely on the real hypervisor to do this for
it when it calls H_ENTER_NESTED.
Fixes: c1fe190c06 ("powerpc: Add force enable of DAWR on P9 option")
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Build failure was introduced by the commit identified below,
due to missed macro expension leading to wrong called function's name.
arch/powerpc/kernel/head_fsl_booke.o: In function `SystemCall':
arch/powerpc/kernel/head_fsl_booke.S:416: undefined reference to `kvmppc_handler_BOOKE_INTERRUPT_SYSCALL_SPRN_SRR1'
Makefile:1052: recipe for target 'vmlinux' failed
The called function should be kvmppc_handler_8_0x01B(). This patch fixes it.
Reported-by: Paul Mackerras <paulus@ozlabs.org>
Fixes: 1a4b739bbb ("powerpc/32: implement fast entry for syscalls on BOOKE")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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: 56c46bba9b ("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>
Use r10 instead of r9 to calculate CPU offset as r9 contains
the value from SRR1 which is used later.
Fixes: 1a4b739bbb ("powerpc/32: implement fast entry for syscalls on BOOKE")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
The patch referenced below moved the loading of segment registers
out of load_up_mmu() in order to do it earlier in the boot sequence.
However, the secondary CPU still needs it to be done when loading up
the MMU.
Reported-by: Erhard F. <erhard_f@mailbox.org>
Fixes: 215b823707 ("powerpc/32s: set up an early static hash table for KASAN")
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
It's common for the platform to replace the cache device nodes after a
migration. Since the cacheinfo code is never informed about this, it
never drops its references to the source system's cache nodes, causing
it to wind up in an inconsistent state resulting in warnings and oopses
as soon as CPU online/offline occurs after the migration, e.g.
cache for /cpus/l3-cache@3113(Unified) refers to cache for /cpus/l2-cache@200d(Unified)
WARNING: CPU: 15 PID: 86 at arch/powerpc/kernel/cacheinfo.c:176 release_cache+0x1bc/0x1d0
[...]
NIP release_cache+0x1bc/0x1d0
LR release_cache+0x1b8/0x1d0
Call Trace:
release_cache+0x1b8/0x1d0 (unreliable)
cacheinfo_cpu_offline+0x1c4/0x2c0
unregister_cpu_online+0x1b8/0x260
cpuhp_invoke_callback+0x114/0xf40
cpuhp_thread_fun+0x270/0x310
smpboot_thread_fn+0x2c8/0x390
kthread+0x1b8/0x1c0
ret_from_kernel_thread+0x5c/0x68
Using device tree notifiers won't work since we want to rebuild the
hierarchy only after all the removals and additions have occurred and
the device tree is in a consistent state. Call cacheinfo_teardown()
before processing device tree updates, and rebuild the hierarchy
afterward.
Fixes: 410bccf978 ("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>
CPU online/offline code paths are sensitive to parts of the device
tree (various cpu node properties, cache nodes) that can be changed as
a result of a migration.
Prevent CPU hotplug while the device tree potentially is inconsistent.
Fixes: 410bccf978 ("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>
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: 410bccf978 ("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>
During post-migration device tree updates, we can oops in
pseries_update_drconf_memory() if the source device tree has an
ibm,dynamic-memory-v2 property and the destination has a
ibm,dynamic_memory (v1) property. The notifier processes an "update"
for the ibm,dynamic-memory property but it's really an add in this
scenario. So make sure the old property object is there before
dereferencing it.
Fixes: 2b31e3aec1 ("powerpc/drmem: Add support for ibm, dynamic-memory-v2 property")
Cc: stable@vger.kernel.org # v4.16+
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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>
