In preparation for an instruction data type that can not be directly
used with the '==' operator use functions for checking equality.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Balamuruhan S <bala24@linux.ibm.com>
Link: https://lore.kernel.org/r/20200506034050.24806-11-jniethe5@gmail.com
Use a function for byte swapping instructions in preparation of a more
complicated instruction type.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Balamuruhan S <bala24@linux.ibm.com>
Link: https://lore.kernel.org/r/20200506034050.24806-10-jniethe5@gmail.com
In preparation for using a data type for instructions that can not be
directly used with the '>>' operator use a function for getting the op
code of an instruction.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-9-jniethe5@gmail.com
In preparation for introducing a more complicated instruction type to
accommodate prefixed instructions use an accessor for getting an
instruction as a u32.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-8-jniethe5@gmail.com
In preparation for instructions having a more complex data type start
using a macro, ppc_inst(), for making an instruction out of a u32. A
macro is used so that instructions can be used as initializer elements.
Currently this does nothing, but it will allow for creating a data type
that can represent prefixed instructions.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
[mpe: Change include guard to _ASM_POWERPC_INST_H]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-7-jniethe5@gmail.com
create_branch(), create_cond_branch() and translate_branch() return the
instruction that they create, or return 0 to signal an error. Separate
these concerns in preparation for an instruction type that is not just
an unsigned int. Fill the created instruction to a pointer passed as
the first parameter to the function and use a non-zero return value to
signify an error.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Alistair Popple <alistair@popple.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-6-jniethe5@gmail.com
The instructions for xmon's breakpoint are stored bpt_table[] which is in
the data section. This is problematic as the data section may be marked
as no execute. Move bpt_table[] to the text section.
Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-4-jniethe5@gmail.com
System Reset and Machine Check interrupts that are not recoverable due
to being nested or interrupting when RI=0 currently panic. This is not
necessary, and can often just kill the current context and recover.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Link: https://lore.kernel.org/r/20200508043408.886394-16-npiggin@gmail.com
Similarly to the previous patch, do not trace system reset. This code
is used when there is a crash or hang, and tracing disturbs the system
more and has been known to crash in the crash handling path.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/20200508043408.886394-15-npiggin@gmail.com
Rather than notrace annotations throughout a significant part of the
machine check code across kernel/ pseries/ and powernv/ which can
easily be broken and is infrequently tested, use paca->ftrace_enabled
to blanket-disable tracing of the real-mode non-maskable handler.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Link: https://lore.kernel.org/r/20200508043408.886394-14-npiggin@gmail.com
machine_check_early() is taken as an NMI, so nmi_enter() is used
there. machine_check_exception() is no longer taken as an NMI (it's
invoked via irq_work in the case a machine check hits in kernel mode),
so remove the nmi_enter() from that case.
In NMI context, hash faults don't try to refill the hash table, which
can lead to crashes accessing non-pinned kernel pages. System reset
still has this potential problem.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Drop change in show_regs() which breaks Book3E]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200508043408.886394-12-npiggin@gmail.com
This allows rtas_args to be put on the machine check stack, which
avoids a lot of complications with re-entrancy deadlocks.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Link: https://lore.kernel.org/r/20200508043408.886394-10-npiggin@gmail.com
A spare interrupt stack slot is needed to save irq state when
reconciling NMIs (sreset and decrementer soft-nmi). _DAR is used
for this, but we want to reconcile machine checks as well, which
do use _DAR. Switch to using RESULT instead, as it's used by
system calls.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200508043408.886394-4-npiggin@gmail.com
The architecture allows for machine check exceptions to cause idle
wakeups which resume at the 0x200 address which has to return via
the idle wakeup code, but the early machine check handler is run
first.
The case of a no state-loss sleep is broken because the early
handler uses non-volatile register r1 , which is needed for the wakeup
protocol, but it is not restored.
Fix this by loading r1 from the MCE exception frame before returning
to the idle wakeup code. Also update the comment which has become
stale since the idle rewrite in C.
This crash was found and fix confirmed with a machine check injection
test in qemu powernv model (which is not upstream in qemu yet).
Fixes: 10d91611f4 ("powerpc/64s: Reimplement book3s idle code in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200508043408.886394-2-npiggin@gmail.com
EEH device state is currently removed (by eeh_remove_device()) during
the device release handler, which is invoked as the device's reference
count drops to zero. This may take some time, or forever, as other
threads may hold references.
However, the PCI device state is released synchronously by
pci_stop_and_remove_bus_device(). This mismatch causes problems, for
example the device may be re-discovered as a new device before the
release handler has been called, leaving the PCI and EEH state
mismatched.
So instead, call eeh_remove_device() from the bus device removal
handlers, which are called synchronously in the removal path.
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0a1f5105d3a33b1c090bba31de63eb0cdd25de7b.1588045502.git.sbobroff@linux.ibm.com
Currently we don't report anything useful in /proc/<pid>/status:
$ grep Speculation_Store_Bypass /proc/self/status
Speculation_Store_Bypass: unknown
Our mitigation is currently always a barrier instruction, which
doesn't map that well onto the existing possibilities for the PR_SPEC
values.
However even if we added a "barrier" type PR_SPEC value, userspace
would still need to consult some other source to work out which type
of barrier to use. So reporting "vulnerable" seems sufficient, as
userspace can see that and then consult its source to determine what
barrier to use.
Signed-off-by: Gustavo Walbon <gwalbon@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200402124929.3574166-1-mpe@ellerman.id.au
Aneesh increased the size of struct pt_regs by 16 bytes and started
seeing this WARN_ON:
smp: Bringing up secondary CPUs ...
------------[ cut here ]------------
WARNING: CPU: 0 PID: 0 at arch/powerpc/kernel/process.c:455 giveup_all+0xb4/0x110
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.7.0-rc2-gcc-8.2.0-1.g8f6a41f-default+ #318
NIP: c00000000001a2b4 LR: c00000000001a29c CTR: c0000000031d0000
REGS: c0000000026d3980 TRAP: 0700 Not tainted (5.7.0-rc2-gcc-8.2.0-1.g8f6a41f-default+)
MSR: 800000000282b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 48048224 XER: 00000000
CFAR: c000000000019cc8 IRQMASK: 1
GPR00: c00000000001a264 c0000000026d3c20 c0000000026d7200 800000000280b033
GPR04: 0000000000000001 0000000000000000 0000000000000077 30206d7372203164
GPR08: 0000000000002000 0000000002002000 800000000280b033 3230303030303030
GPR12: 0000000000008800 c0000000031d0000 0000000000800050 0000000002000066
GPR16: 000000000309a1a0 000000000309a4b0 000000000309a2d8 000000000309a890
GPR20: 00000000030d0098 c00000000264da40 00000000fd620000 c0000000ff798080
GPR24: c00000000264edf0 c0000001007469f0 00000000fd620000 c0000000020e5e90
GPR28: c00000000264edf0 c00000000264d200 000000001db60000 c00000000264d200
NIP [c00000000001a2b4] giveup_all+0xb4/0x110
LR [c00000000001a29c] giveup_all+0x9c/0x110
Call Trace:
[c0000000026d3c20] [c00000000001a264] giveup_all+0x64/0x110 (unreliable)
[c0000000026d3c90] [c00000000001ae34] __switch_to+0x104/0x480
[c0000000026d3cf0] [c000000000e0b8a0] __schedule+0x320/0x970
[c0000000026d3dd0] [c000000000e0c518] schedule_idle+0x38/0x70
[c0000000026d3df0] [c00000000019c7c8] do_idle+0x248/0x3f0
[c0000000026d3e70] [c00000000019cbb8] cpu_startup_entry+0x38/0x40
[c0000000026d3ea0] [c000000000011bb0] rest_init+0xe0/0xf8
[c0000000026d3ed0] [c000000002004820] start_kernel+0x990/0x9e0
[c0000000026d3f90] [c00000000000c49c] start_here_common+0x1c/0x400
Which was unexpected. The warning is checking the thread.regs->msr
value of the task we are switching from:
usermsr = tsk->thread.regs->msr;
...
WARN_ON((usermsr & MSR_VSX) && !((usermsr & MSR_FP) && (usermsr & MSR_VEC)));
ie. if MSR_VSX is set then both of MSR_FP and MSR_VEC are also set.
Dumping tsk->thread.regs->msr we see that it's: 0x1db60000
Which is not a normal looking MSR, in fact the only valid bit is
MSR_VSX, all the other bits are reserved in the current definition of
the MSR.
We can see from the oops that it was swapper/0 that we were switching
from when we hit the warning, ie. init_task. So its thread.regs points
to the base (high addresses) in init_stack.
Dumping the content of init_task->thread.regs, with the members of
pt_regs annotated (the 16 bytes larger version), we see:
0000000000000000 c000000002780080 gpr[0] gpr[1]
0000000000000000 c000000002666008 gpr[2] gpr[3]
c0000000026d3ed0 0000000000000078 gpr[4] gpr[5]
c000000000011b68 c000000002780080 gpr[6] gpr[7]
0000000000000000 0000000000000000 gpr[8] gpr[9]
c0000000026d3f90 0000800000002200 gpr[10] gpr[11]
c000000002004820 c0000000026d7200 gpr[12] gpr[13]
000000001db60000 c0000000010aabe8 gpr[14] gpr[15]
c0000000010aabe8 c0000000010aabe8 gpr[16] gpr[17]
c00000000294d598 0000000000000000 gpr[18] gpr[19]
0000000000000000 0000000000001ff8 gpr[20] gpr[21]
0000000000000000 c00000000206d608 gpr[22] gpr[23]
c00000000278e0cc 0000000000000000 gpr[24] gpr[25]
000000002fff0000 c000000000000000 gpr[26] gpr[27]
0000000002000000 0000000000000028 gpr[28] gpr[29]
000000001db60000 0000000004750000 gpr[30] gpr[31]
0000000002000000 000000001db60000 nip msr
0000000000000000 0000000000000000 orig_r3 ctr
c00000000000c49c 0000000000000000 link xer
0000000000000000 0000000000000000 ccr softe
0000000000000000 0000000000000000 trap dar
0000000000000000 0000000000000000 dsisr result
0000000000000000 0000000000000000 ppr kuap
0000000000000000 0000000000000000 pad[2] pad[3]
This looks suspiciously like stack frames, not a pt_regs. If we look
closely we can see return addresses from the stack trace above,
c000000002004820 (start_kernel) and c00000000000c49c (start_here_common).
init_task->thread.regs is setup at build time in processor.h:
#define INIT_THREAD { \
.ksp = INIT_SP, \
.regs = (struct pt_regs *)INIT_SP - 1, /* XXX bogus, I think */ \
The early boot code where we setup the initial stack is:
LOAD_REG_ADDR(r3,init_thread_union)
/* set up a stack pointer */
LOAD_REG_IMMEDIATE(r1,THREAD_SIZE)
add r1,r3,r1
li r0,0
stdu r0,-STACK_FRAME_OVERHEAD(r1)
Which creates a stack frame of size 112 bytes (STACK_FRAME_OVERHEAD).
Which is far too small to contain a pt_regs.
So the result is init_task->thread.regs is pointing at some stack
frames on the init stack, not at a pt_regs.
We have gotten away with this for so long because with pt_regs at its
current size the MSR happens to point into the first frame, at a
location that is not written to by the early asm. With the 16 byte
expansion the MSR falls into the second frame, which is used by the
compiler, and collides with a saved register that tends to be
non-zero.
As far as I can see this has been wrong since the original merge of
64-bit ppc support, back in 2002.
Conceptually swapper should have no regs, it never entered from
userspace, and in fact that's what we do on 32-bit. It's also
presumably what the "bogus" comment is referring to.
So I think the right fix is to just not-initialise regs at all. I'm
slightly worried this will break some code that isn't prepared for a
NULL regs, but we'll have to see.
Remove the comment in head_64.S which refers to us setting up the
regs (even though we never did), and is otherwise not really accurate
any more.
Reported-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/20200428123130.73078-1-mpe@ellerman.id.au
It's not very nice to zero trap for this, because then system calls no
longer have trap_is_syscall(regs) invariant, and we can't distinguish
between sc and scv system calls (in a later patch).
Take one last unused bit from the low bits of the pt_regs.trap word
for this instead. There is not a really good reason why it should be
in trap as opposed to another field, but trap has some concept of
flags and it exists. Ideally I think we would move trap to 2-byte
field and have 2 more bytes available independently.
Add a selftests case for this, which can be seen to fail if
trap_norestart() is changed to return false.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Make them static inlines]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200507121332.2233629-4-mpe@ellerman.id.au
A new system call interrupt will be added with a new trap number.
Hide the explicit 0xc00 test behind an accessor to reduce churn
in callers.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Make it a static inline]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200507121332.2233629-3-mpe@ellerman.id.au
The pt_regs.trap field keeps 4 low bits for some metadata about the
trap or how it was handled, which is masked off in order to test the
architectural trap number.
Add a set_trap() accessor to set this, equivalent to TRAP() for
returning it. This is actually not quite the equivalent of TRAP()
because it always clears the low bits, which may be harmless if
it can only be updated via ptrace syscall, but it seems dangerous.
In fact settting TRAP from ptrace doesn't seem like a great idea
so maybe it's better deleted.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Make it a static inline rather than a shouty macro]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200507121332.2233629-2-mpe@ellerman.id.au
POSIX defines faccessat() as having a fourth "flags" argument, while the
linux syscall doesn't have it. Glibc tries to emulate AT_EACCESS and
AT_SYMLINK_NOFOLLOW, but AT_EACCESS emulation is broken.
Add a new faccessat(2) syscall with the added flags argument and implement
both flags.
The value of AT_EACCESS is defined in glibc headers to be the same as
AT_REMOVEDIR. Use this value for the kernel interface as well, together
with the explanatory comment.
Also add AT_EMPTY_PATH support, which is not documented by POSIX, but can
be useful and is trivial to implement.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
When CONFIG_VIRT_CPU_ACCOUNTING is selected, system call exception
handler doesn't fit below 0xd00 and build fails.
As exception 0xd00 doesn't exist and is never generated by 40x,
comment it out in order to get more space for system call exception.
Fixes: 9e27086292 ("powerpc/32: Warn and return ENOSYS on syscalls from kernel")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/633165d72f75b4ef4c0901aebe99d3915c93e9a2.1589043863.git.christophe.leroy@csgroup.eu
Replace relaswap with built-in one, because relaswap
does a simple byte to byte swap.
Since Spectre mitigations have made indirect function calls more
expensive, and the default simple byte copies swap is implemented
without them, an "optimized" custom swap function is now
a waste of time as well as code.
Signed-off-by: Andrey Abramov <st5pub@yandex.ru>
Reviewed-by: George Spelvin <lkml@sdf.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/994931554238042@iva8-b333b7f98ab0.qloud-c.yandex.net
There are other clocks than the standard ones, for instance
per process clocks. Therefore, being above the last standard clock
doesn't mean it is a bad clock. So, fallback to syscall instead
of returning -EINVAL inconditionaly.
Fixes: e33ffc956b ("powerpc/vdso32: implement clock_getres entirely")
Cc: stable@vger.kernel.org # v5.6+
Reported-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Tested-by: Aurelien Jarno <aurelien@aurel32.net>
Link: https://lore.kernel.org/r/7316a9e2c0c2517923eb4b0411c4a08d15e675a4.1589017281.git.christophe.leroy@csgroup.eu
To prevent verifying the kernel module appended signature
twice (finit_module), once by the module_sig_check() and again by IMA,
powerpc secure boot rules define an IMA architecture specific policy
rule only if CONFIG_MODULE_SIG_FORCE is not enabled. This,
unfortunately, does not take into account the ability of enabling
"sig_enforce" on the boot command line (module.sig_enforce=1).
Including the IMA module appraise rule results in failing the
finit_module syscall, unless the module signing public key is loaded
onto the IMA keyring.
This patch fixes secure boot policy rules to be based on
CONFIG_MODULE_SIG instead.
Fixes: 4238fad366 ("powerpc/ima: Add support to initialize ima policy rules")
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Link: https://lore.kernel.org/r/1588342612-14532-1-git-send-email-nayna@linux.ibm.com
Interrupts that use fast_interrupt_return actually do lock AMR, but
they have been ones which tend to come from userspace (or kernel bugs)
in radix mode. With kuap on hash, segment interrupts are taken in
kernel often, which quickly breaks due to the missing restore.
Fixes: 890274c2dc ("powerpc/64s: Implement KUAP for Radix MMU")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200429065654.1677541-6-npiggin@gmail.com
This merges the lockless page table walk rework series from Aneesh.
Because it touches powerpc KVM code we are sharing it with the kvm-ppc
tree in our topic/ppc-kvm branch.
This is the cover letter from Aneesh:
Avoid IPI while updating page table entries.
Problem Summary:
Slow termination of KVM guest with large guest RAM config due to a
large number of IPIs that were caused by clearing level 1 PTE
entries (THP) entries. This is shown in the stack trace below.
- qemu-system-ppc [kernel.vmlinux] [k] smp_call_function_many
- smp_call_function_many
- 36.09% smp_call_function_many
serialize_against_pte_lookup
radix__pmdp_huge_get_and_clear
zap_huge_pmd
unmap_page_range
unmap_vmas
unmap_region
__do_munmap
__vm_munmap
sys_munmap
system_call
__munmap
qemu_ram_munmap
qemu_anon_ram_free
reclaim_ramblock
call_rcu_thread
qemu_thread_start
start_thread
__clone
Why we need to do IPI when clearing PMD entries:
This was added as part of commit: 13bd817bb8 ("powerpc/thp: Serialize pmd clear against a linux page table walk")
serialize_against_pte_lookup makes sure that all parallel lockless
page table walk completes before we convert a PMD pte entry to regular
pmd entry. We end up doing that conversion in the below scenarios
1) __split_huge_zero_page_pmd
2) do_huge_pmd_wp_page_fallback
3) MADV_DONTNEED running parallel to page faults.
local_irq_disable and lockless page table walk:
The lockless page table walk work with the assumption that we can
dereference the page table contents without holding a lock. For this
to work, we need to make sure we read the page table contents
atomically and page table pages are not going to be freed/released
while we are walking the table pages. We can achieve by using a rcu
based freeing for page table pages or if the architecture implements
broadcast tlbie, we can block the IPI as we walk the page table pages.
To support both the above framework, lockless page table walk is done
with irq disabled instead of rcu_read_lock()
We do have two interface for lockless page table walk, gup fast and
__find_linux_pte. This patch series makes __find_linux_pte table walk
safe against the conversion of PMD PTE to regular PMD.
gup fast:
gup fast is already safe against THP split because kernel now
differentiate between a pmd split and a compound page split. gup fast
can run parallel to a pmd split and we prevent a parallel gup fast to
a hugepage split, by freezing the page refcount and failing the
speculative page ref increment.
Similar to how gup is safe against parallel pmd split, this patch
series updates the __find_linux_pte callers to be safe against a
parallel pmd split. We do that by enforcing the following rules.
1) Don't reload the pte value, because that can be updated in
parallel.
2) Code should be able to work with a stale PTE value and not the
recent one. ie, the pte value that we are looking at may not be the
latest value in the page table.
3) Before looking at pte value check for _PAGE_PTE bit. We now do this
as part of pte_present() check.
Performance:
This speeds up Qemu guest RAM del/unplug time as below
128 core, 496GB guest:
Without patch:
munmap start: timer = 13162 ms, PID=7684
munmap finish: timer = 95312 ms, PID=7684 - delta = 82150 ms
With patch (upto removing IPI)
munmap start: timer = 196449 ms, PID=6681
munmap finish: timer = 196488 ms, PID=6681 - delta = 39ms
With patch (with adding the tlb invalidate in pmdp_huge_get_and_clear_full)
munmap start: timer = 196345 ms, PID=6879
munmap finish: timer = 196714 ms, PID=6879 - delta = 369ms
Link: https://lore.kernel.org/r/20200505071729.54912-1-aneesh.kumar@linux.ibm.com
A lockless page table walk should be safe against parallel THP collapse, THP
split and madvise(MADV_DONTNEED)/parallel fault. This patch makes sure kernel
won't reload the pteval when checking for different conditions. The patch also added
a check for pte_present to make sure the kernel is indeed operating
on a PTE and not a pointer to level 0 table page.
The pfn value we find here can be different from the actual pfn on which
machine check happened. This can happen if we raced with a parallel update
of the page table. In such a scenario we end up isolating a wrong pfn. But that
doesn't have any other side effect.
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/20200505071729.54912-7-aneesh.kumar@linux.ibm.com
This is only used with init_mm currently. Walking init_mm is much simpler
because we don't need to handle concurrent page table like other mm_context
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/20200505071729.54912-5-aneesh.kumar@linux.ibm.com
Commit 0962e8004e ("powerpc/prom: Scan reserved-ranges node for
memory reservations") enabled support to parse reserved-ranges DT
node and reserve kernel memory falling in these ranges for F/W
purposes. Memory reserved for FADump should not overlap with these
ranges as it could corrupt memory meant for F/W or crash'ed kernel
memory to be exported as vmcore.
But since commit 579ca1a276 ("powerpc/fadump: make use of memblock's
bottom up allocation mode"), memblock_find_in_range() is being used to
find the appropriate area to reserve memory for FADump, which can't
account for reserved-ranges as these ranges are reserved only after
FADump memory reservation.
With reserved-ranges now being populated during early boot, look out
for these memory ranges while reserving memory for FADump. Without
this change, MPIPL on PowerNV systems aborts with hostboot failure,
when memory reserved for FADump is less than 4096MB.
Fixes: 579ca1a276 ("powerpc/fadump: make use of memblock's bottom up allocation mode")
Cc: stable@vger.kernel.org
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/158737297693.26700.16193820746269425424.stgit@hbathini.in.ibm.com
At times, memory ranges have to be looked up during early boot, when
kernel couldn't be initialized for dynamic memory allocation. In fact,
reserved-ranges look up is needed during FADump memory reservation.
Without accounting for reserved-ranges in reserving memory for FADump,
MPIPL boot fails with memory corruption issues. So, extend memory
ranges handling to support static allocation and populate reserved
memory ranges during early boot.
Fixes: dda9dbfeeb ("powerpc/fadump: consider reserved ranges while releasing memory")
Cc: stable@vger.kernel.org
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/158737294432.26700.4830263187856221314.stgit@hbathini.in.ibm.com
The system reset interrupt handler locks AMR and exits with
EXCEPTION_RESTORE_REGS without restoring AMR. Similarly to the
soft-NMI handler, it needs to restore.
Fixes: 890274c2dc ("powerpc/64s: Implement KUAP for Radix MMU")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200429065654.1677541-5-npiggin@gmail.com
Any kind of WARN causes a program check that will crash with
unrecoverable exception if it occurs when RI is clear.
Fixes: 68b34588e2 ("powerpc/64/sycall: Implement syscall entry/exit logic in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200429065654.1677541-2-npiggin@gmail.com
Hugh reported that his trusty G5 crashed after a few hours under load
with an "Unrecoverable exception 380".
The crash is in interrupt_return() where we check lazy_irq_pending(),
which calls get_paca() and with CONFIG_DEBUG_PREEMPT=y that goes to
check_preemption_disabled() via debug_smp_processor_id().
As Nick explained on the list:
Problem is MSR[RI] is cleared here, ready to do the last few things
for interrupt return where we're not allowed to take any other
interrupts.
SLB interrupts can happen just about anywhere aside from kernel
text, global variables, and stack. When that hits, it appears to be
unrecoverable due to RI=0.
The problematic access is in preempt_count() which is:
return READ_ONCE(current_thread_info()->preempt_count);
Because of THREAD_INFO_IN_TASK, current_thread_info() just points to
current, so the access is to somewhere in kernel memory, but not on
the stack or in .data, which means it can cause an SLB miss. If we
take an SLB miss with RI=0 it is fatal.
The easiest solution is to add a version of lazy_irq_pending() that
doesn't do the preemption check and call it from the interrupt return
path.
Fixes: 68b34588e2 ("powerpc/64/sycall: Implement syscall entry/exit logic in C")
Reported-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200502143316.929341-1-mpe@ellerman.id.au
On Pseries LPARs, to calculate utilization, we need to know the
[S]PURR ticks when the CPUs were busy or idle.
The total PURR and SPURR ticks are already exposed via the per-cpu
sysfs files "purr" and "spurr". This patch adds support for exposing
the idle PURR and SPURR ticks via new per-cpu sysfs files named
"idle_purr" and "idle_spurr".
This patch also adds helper functions to accurately read the values of
idle_purr and idle_spurr especially from an interrupt context between
when the interrupt has occurred between the pseries_idle_prolog() and
pseries_idle_epilog(). This will ensure that the idle purr/spurr
values corresponding to the latest idle period is accounted for before
these values are read.
Signed-off-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1586249263-14048-5-git-send-email-ego@linux.vnet.ibm.com
CONFIG_PPC_KUAP_DEBUG is not selectable because it depends on PPC_32
which doesn't exists.
Fixing it leads to a deadlock due to a vital register getting
clobbered in _switch().
Change dependency to PPC32 and use r0 instead of r4 in _switch()
Fixes: e2fb9f5444 ("powerpc/32: Prepare for Kernel Userspace Access Protection")
Cc: stable@vger.kernel.org # v5.2+
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/540242f7d4573f7cdf1b3bf46bb35f743b2cd68f.1587124651.git.christophe.leroy@c-s.fr
If {i,d}-cache-block-size is set and {i,d}-cache-line-size is not, use
the block-size value for both. Per the devicetree spec cache-line-size
is only needed if it differs from the block size.
Originally the code would fallback from block size to line size. An
error message was printed if both properties were missing.
Later the code was refactored to use clearer names and logic but it
inadvertently made line size a required property, meaning on systems
without a line size property we fall back to the default from the
cputable.
On powernv (OPAL) platforms, since the introduction of device tree CPU
features (5a61ef74f2 ("powerpc/64s: Support new device tree binding
for discovering CPU features")), that has led to the wrong value being
used, as the fallback value is incorrect for Power8/Power9 CPUs.
The incorrect values flow through to the VDSO and also to the sysconf
values, SC_LEVEL1_ICACHE_LINESIZE etc.
Fixes: bd067f83b0 ("powerpc/64: Fix naming of cache block vs. cache line")
Cc: stable@vger.kernel.org # v4.11+
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reported-by: Qian Cai <cai@lca.pw>
[mpe: Add even more detail to change log]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200416221908.7886-1-chris.packham@alliedtelesis.co.nz
set_thread_uses_vas() sets used_vas flag for a process that opened VAS
window and issue CP_ABORT during context switch for only that process.
In multi-thread application, windows can be shared. For example Thread
A can open a window and Thread B can run COPY/PASTE instructions to
send NX request which may cause corruption or snooping or a covert
channel Also once this flag is set, continue to run CP_ABORT even the
VAS window is closed.
So define vas-windows counter in process mm_context, increment this
counter for each window open and decrement it for window close. If
vas-windows is set, issue CP_ABORT during context switch. It means
clear the foreign real address mapping only if the process / thread
uses COPY/PASTE. Then disable it for that process if windows are not
open.
Moved set_thread_uses_vas() code to vas_tx_win_open() as this
functionality is needed only for userspace open windows. We are adding
VAS userspace support along with this fix. So no need to include this
fix in stable releases.
Fixes: 9d2a4d7133 ("powerpc: Define set_thread_uses_vas()")
Signed-off-by: Haren Myneni <haren@linux.ibm.com>
Reported-by: Nicholas Piggin <npiggin@gmail.com>
Suggested-by: Milton Miller <miltonm@us.ibm.com>
Suggested-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1587017291.2275.1077.camel@hbabu-laptop
- A fix for a crash in machine check handling on pseries (ie. guests)
- A small series to make it possible to disable CONFIG_COMPAT, and turn it off
by default for ppc64le where it's not used.
- A few other miscellaneous fixes and small improvements.
Thanks to:
Alexey Kardashevskiy, Anju T Sudhakar, Arnd Bergmann, Christophe Leroy, Dan
Carpenter, Ganesh Goudar, Geert Uytterhoeven, Geoff Levand, Mahesh Salgaonkar,
Markus Elfring, Michal Suchanek, Nicholas Piggin, Stephen Boyd, Wen Xiong.
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Merge tag 'powerpc-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull more powerpc updates from Michael Ellerman:
"The bulk of this is the series to make CONFIG_COMPAT user-selectable,
it's been around for a long time but was blocked behind the
syscall-in-C series.
Plus there's also a few fixes and other minor things.
Summary:
- A fix for a crash in machine check handling on pseries (ie. guests)
- A small series to make it possible to disable CONFIG_COMPAT, and
turn it off by default for ppc64le where it's not used.
- A few other miscellaneous fixes and small improvements.
Thanks to: Alexey Kardashevskiy, Anju T Sudhakar, Arnd Bergmann,
Christophe Leroy, Dan Carpenter, Ganesh Goudar, Geert Uytterhoeven,
Geoff Levand, Mahesh Salgaonkar, Markus Elfring, Michal Suchanek,
Nicholas Piggin, Stephen Boyd, Wen Xiong"
* tag 'powerpc-5.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
selftests/powerpc: Always build the tm-poison test 64-bit
powerpc: Improve ppc_save_regs()
Revert "powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled"
powerpc/time: Replace <linux/clk-provider.h> by <linux/of_clk.h>
powerpc/pseries/ddw: Extend upper limit for huge DMA window for persistent memory
powerpc/perf: split callchain.c by bitness
powerpc/64: Make COMPAT user-selectable disabled on littleendian by default.
powerpc/64: make buildable without CONFIG_COMPAT
powerpc/perf: consolidate valid_user_sp -> invalid_user_sp
powerpc/perf: consolidate read_user_stack_32
powerpc: move common register copy functions from signal_32.c to signal.c
powerpc: Add back __ARCH_WANT_SYS_LLSEEK macro
powerpc/ps3: Set CONFIG_UEVENT_HELPER=y in ps3_defconfig
powerpc/ps3: Remove an unneeded NULL check
powerpc/ps3: Remove duplicate error message
powerpc/powernv: Re-enable imc trace-mode in kernel
powerpc/perf: Implement a global lock to avoid races between trace, core and thread imc events.
powerpc/pseries: Fix MCE handling on pseries
selftests/eeh: Skip ahci adapters
powerpc/64s: Fix doorbell wakeup msgclr optimisation
Generated files are also checked by sparse that's why add newline to
remove sparse (C=1) warning.
The issue was found on Microblaze and reported like this:
./arch/microblaze/include/generated/uapi/asm/unistd_32.h:438:45: warning:
no newline at end of file
Mips and PowerPC have it already but let's align with style used by m68k.
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Stefan Asserhall <stefan.asserhall@xilinx.com>
Acked-by: Max Filippov <jcmvbkbc@gmail.com> (xtensa)
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Burton <paulburton@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rich Felker <dalias@libc.org>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/4d32ab4e1fb2edb691d2e1687e8fb303c09fd023.1581504803.git.michal.simek@xilinx.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- A large series from Nick for 64-bit to further rework our exception vectors,
and rewrite portions of the syscall entry/exit and interrupt return in C. The
result is much easier to follow code that is also faster in general.
- Cleanup of our ptrace code to split various parts out that had become badly
intertwined with #ifdefs over the years.
- Changes to our NUMA setup under the PowerVM hypervisor which should
hopefully avoid non-sensical topologies which can lead to warnings from the
workqueue code and other problems.
- MAINTAINERS updates to remove some of our old orphan entries and update the
status of others.
- Quite a few other small changes and fixes all over the map.
Thanks to:
Abdul Haleem, afzal mohammed, Alexey Kardashevskiy, Andrew Donnellan, Aneesh
Kumar K.V, Balamuruhan S, Cédric Le Goater, Chen Zhou, Christophe JAILLET,
Christophe Leroy, Christoph Hellwig, Clement Courbet, Daniel Axtens, David
Gibson, Douglas Miller, Fabiano Rosas, Fangrui Song, Ganesh Goudar, Gautham R.
Shenoy, Greg Kroah-Hartman, Greg Kurz, Gustavo Luiz Duarte, Hari Bathini, Ilie
Halip, Jan Kara, Joe Lawrence, Joe Perches, Kajol Jain, Larry Finger,
Laurentiu Tudor, Leonardo Bras, Libor Pechacek, Madhavan Srinivasan, Mahesh
Salgaonkar, Masahiro Yamada, Masami Hiramatsu, Mauricio Faria de Oliveira,
Michael Neuling, Michal Suchanek, Mike Rapoport, Nageswara R Sastry, Nathan
Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick Desaulniers,
Oliver O'Halloran, Po-Hsu Lin, Pratik Rajesh Sampat, Rasmus Villemoes, Ravi
Bangoria, Roman Bolshakov, Sam Bobroff, Sandipan Das, Santosh S, Sedat Dilek,
Segher Boessenkool, Shilpasri G Bhat, Sourabh Jain, Srikar Dronamraju, Stephen
Rothwell, Tyrel Datwyler, Vaibhav Jain, YueHaibing.
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Merge tag 'powerpc-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc updates from Michael Ellerman:
"Slightly late as I had to rebase mid-week to insert a bug fix:
- A large series from Nick for 64-bit to further rework our exception
vectors, and rewrite portions of the syscall entry/exit and
interrupt return in C. The result is much easier to follow code
that is also faster in general.
- Cleanup of our ptrace code to split various parts out that had
become badly intertwined with #ifdefs over the years.
- Changes to our NUMA setup under the PowerVM hypervisor which should
hopefully avoid non-sensical topologies which can lead to warnings
from the workqueue code and other problems.
- MAINTAINERS updates to remove some of our old orphan entries and
update the status of others.
- Quite a few other small changes and fixes all over the map.
Thanks to: Abdul Haleem, afzal mohammed, Alexey Kardashevskiy, Andrew
Donnellan, Aneesh Kumar K.V, Balamuruhan S, Cédric Le Goater, Chen
Zhou, Christophe JAILLET, Christophe Leroy, Christoph Hellwig, Clement
Courbet, Daniel Axtens, David Gibson, Douglas Miller, Fabiano Rosas,
Fangrui Song, Ganesh Goudar, Gautham R. Shenoy, Greg Kroah-Hartman,
Greg Kurz, Gustavo Luiz Duarte, Hari Bathini, Ilie Halip, Jan Kara,
Joe Lawrence, Joe Perches, Kajol Jain, Larry Finger, Laurentiu Tudor,
Leonardo Bras, Libor Pechacek, Madhavan Srinivasan, Mahesh Salgaonkar,
Masahiro Yamada, Masami Hiramatsu, Mauricio Faria de Oliveira, Michael
Neuling, Michal Suchanek, Mike Rapoport, Nageswara R Sastry, Nathan
Chancellor, Nathan Lynch, Naveen N. Rao, Nicholas Piggin, Nick
Desaulniers, Oliver O'Halloran, Po-Hsu Lin, Pratik Rajesh Sampat,
Rasmus Villemoes, Ravi Bangoria, Roman Bolshakov, Sam Bobroff,
Sandipan Das, Santosh S, Sedat Dilek, Segher Boessenkool, Shilpasri G
Bhat, Sourabh Jain, Srikar Dronamraju, Stephen Rothwell, Tyrel
Datwyler, Vaibhav Jain, YueHaibing"
* tag 'powerpc-5.7-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (158 commits)
powerpc: Make setjmp/longjmp signature standard
powerpc/cputable: Remove unnecessary copy of cpu_spec->oprofile_type
powerpc: Suppress .eh_frame generation
powerpc: Drop -fno-dwarf2-cfi-asm
powerpc/32: drop unused ISA_DMA_THRESHOLD
powerpc/powernv: Add documentation for the opal sensor_groups sysfs interfaces
selftests/powerpc: Fix try-run when source tree is not writable
powerpc/vmlinux.lds: Explicitly retain .gnu.hash
powerpc/ptrace: move ptrace_triggered() into hw_breakpoint.c
powerpc/ptrace: create ppc_gethwdinfo()
powerpc/ptrace: create ptrace_get_debugreg()
powerpc/ptrace: split out ADV_DEBUG_REGS related functions.
powerpc/ptrace: move register viewing functions out of ptrace.c
powerpc/ptrace: split out TRANSACTIONAL_MEM related functions.
powerpc/ptrace: split out SPE related functions.
powerpc/ptrace: split out ALTIVEC related functions.
powerpc/ptrace: split out VSX related functions.
powerpc/ptrace: drop PARAMETER_SAVE_AREA_OFFSET
powerpc/ptrace: drop unnecessary #ifdefs CONFIG_PPC64
powerpc/ptrace: remove unused header includes
...
Here are 3 SPDX patches for 5.7-rc1.
One fixes up the SPDX tag for a single driver, while the other two go
through the tree and add SPDX tags for all of the .gitignore files as
needed.
Nothing too complex, but you will get a merge conflict with your current
tree, that should be trivial to handle (one file modified by two things,
one file deleted.)
All 3 of these have been in linux-next for a while, with no reported
issues other than the merge conflict.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx
Pull SPDX updates from Greg KH:
"Here are three SPDX patches for 5.7-rc1.
One fixes up the SPDX tag for a single driver, while the other two go
through the tree and add SPDX tags for all of the .gitignore files as
needed.
Nothing too complex, but you will get a merge conflict with your
current tree, that should be trivial to handle (one file modified by
two things, one file deleted.)
All three of these have been in linux-next for a while, with no
reported issues other than the merge conflict"
* tag 'spdx-5.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx:
ASoC: MT6660: make spdxcheck.py happy
.gitignore: add SPDX License Identifier
.gitignore: remove too obvious comments
This reverts commit ebb37cf3ff.
That commit does not play well with soft-masked irq state
manipulations in idle, interrupt replay, and possibly others due to
tracing code sometimes using irq_work_queue (e.g., in
trace_hardirqs_on()). That can cause PACA_IRQ_DEC to become set when
it is not expected, and be ignored or cleared or cause warnings.
The net result seems to be missing an irq_work until the next timer
interrupt in the worst case which is usually not going to be noticed,
however it could be a long time if the tick is disabled, which is
against the spirit of irq_work and might cause real problems.
The idea is still solid, but it would need more work. It's not really
clear if it would be worth added complexity, so revert this for
now (not a straight revert, but replace with a comment explaining why
we might see interrupts happening, and gives git blame something to
find).
Fixes: ebb37cf3ff ("powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200402120401.1115883-1-npiggin@gmail.com
The PowerPC time code is not a clock provider, and just needs to call
of_clk_init().
Hence it can include <linux/of_clk.h> instead of <linux/clk-provider.h>.
Remove the #ifdef protecting the of_clk_init() call, as a stub is
available for the !CONFIG_COMMON_CLK case.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200213083804.24315-1-geert+renesas@glider.be
- Unit test for overlays with GPIO hogs
- Improve dma-ranges parsing to handle dma-ranges with multiple entries
- Update dtc to upstream version v1.6.0-2-g87a656ae5ff9
- Improve overlay error reporting
- Device link support for power-domains and hwlocks bindings
- Add vendor prefixes for Beacon, Topwise, ENE, Dell, SG Micro, Elida,
PocketBook, Xiaomi, Linutronix, OzzMaker, Waveshare Electronics, and
ITE Tech
- Add deprecated Marvell vendor prefix 'mrvl'
- A bunch of binding conversions to DT schema continues. Of note, the
common serial and USB connector bindings are converted.
- Add more Arm CPU compatibles
- Drop Mark Rutland as DT maintainer :(
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Merge tag 'devicetree-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree updates from Rob Herring:
- Unit test for overlays with GPIO hogs
- Improve dma-ranges parsing to handle dma-ranges with multiple entries
- Update dtc to upstream version v1.6.0-2-g87a656ae5ff9
- Improve overlay error reporting
- Device link support for power-domains and hwlocks bindings
- Add vendor prefixes for Beacon, Topwise, ENE, Dell, SG Micro, Elida,
PocketBook, Xiaomi, Linutronix, OzzMaker, Waveshare Electronics, and
ITE Tech
- Add deprecated Marvell vendor prefix 'mrvl'
- A bunch of binding conversions to DT schema continues. Of note, the
common serial and USB connector bindings are converted.
- Add more Arm CPU compatibles
- Drop Mark Rutland as DT maintainer :(
* tag 'devicetree-for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (106 commits)
MAINTAINERS: drop an old reference to stm32 pwm timers doc
MAINTAINERS: dt: update etnaviv file reference
dt-bindings: usb: dwc2: fix bindings for amlogic, meson-gxbb-usb
dt-bindings: uniphier-system-bus: fix warning in the example
dt-bindings: display: meson-vpu: fix indentation of reg-names' "items"
dt-bindings: iio: Fix adi, ltc2983 uint64-matrix schema constraints
dt-bindings: power: Fix example for power-domain
dt-bindings: arm: Add some constraints for PSCI nodes
of: some unittest overlays not untracked
of: gpio unittest kfree() wrong object
dt-bindings: phy: convert phy-rockchip-inno-usb2 bindings to yaml
dt-bindings: serial: sh-sci: Convert to json-schema
dt-bindings: serial: Document serialN aliases
dt-bindings: thermal: tsens: Set 'additionalProperties: false'
dt-bindings: thermal: tsens: Fix nvmem-cell-names schema
dt-bindings: vendor-prefixes: Add Beacon vendor prefix
dt-bindings: vendor-prefixes: Add Topwise
of: of_private.h: Replace zero-length array with flexible-array member
docs: dt: fix a broken reference to input.yaml
docs: dt: fix references to ap806-system-controller.txt
...
Commit 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
broke the doorbell wakeup optimisation introduced by commit a9af97aa0a
("powerpc/64s: msgclr when handling doorbell exceptions from system
reset").
This patch restores the msgclr, in C code. It's now done in the system
reset wakeup path rather than doorbell interrupt replay where it used
to be, because it is always the right thing to do in the wakeup case,
but it may be rarely of use in other interrupt replay situations in
which case it's wasted work - we would have to run measurements to see
if that was a worthwhile optimisation, and I suspect it would not be.
The results are similar to those in the original commit, test on POWER8
of context_switch selftests benchmark with polling idle disabled (e.g.,
always nap, giving cross-CPU IPIs) gives the following results:
broken patched
Different threads, same core: 317k/s 375k/s +18.7%
Different cores: 280k/s 282k/s +1.0%
Fixes: 3282a3da25 ("powerpc/64: Implement soft interrupt replay in C")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200402121212.1118218-1-npiggin@gmail.com
Before checking for cpu_type == NULL, this same copy happens, so doing
it here will just write the same value to the t->oprofile_type
again.
Remove the repeated copy, as it is unnecessary.
Signed-off-by: Leonardo Bras <leonardo@linux.ibm.com>
Reviewed-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200215053637.280880-1-leonardo@linux.ibm.com
The ISA_DMA_THRESHOLD variable is set by several platforms but never
referenced.
Remove it.
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/20191125092033.20014-1-rppt@kernel.org
Relocatable kernel builds produce a warning about .gnu.hash being an
orphan section:
ld: warning: orphan section `.gnu.hash' from `linker stubs' being placed in section `.gnu.hash'
If we try to discard it the build fails:
ld -EL -m elf64lppc -pie --orphan-handling=warn --build-id -o
.tmp_vmlinux1 -T ./arch/powerpc/kernel/vmlinux.lds --whole-archive
arch/powerpc/kernel/head_64.o arch/powerpc/kernel/entry_64.o
...
sound/built-in.a net/built-in.a virt/built-in.a --no-whole-archive
--start-group lib/lib.a --end-group
ld: could not find section .gnu.hash
So add an entry to explicitly retain it, as we do for .hash.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200227045933.22967-1-mpe@ellerman.id.au
This reconciles interrupts in the system call case like all other
interrupts. This allows system_call_common to be shared with the scv
system call implementation in a subsequent patch.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-31-npiggin@gmail.com
Regular interrupt return restores NVGPRS whereas lite returns do not.
This is clumsy: most interrupts can return without restoring NVGPRS in
most of the time, but there are special cases that require it (when
registers have been modified by the kernel). So change interrupt
return to not restore NVGPRS, and have interrupt handlers restore them
explicitly in the cases that requires it.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-30-npiggin@gmail.com
Implement the bulk of interrupt return logic in C. The asm return code
must handle a few cases: restoring full GPRs, and emulating stack
store.
The stack store emulation is significantly simplfied, rather than
creating a new return frame and switching to that before performing
the store, it uses the PACA to keep a scratch register around to
perform the store.
The asm return code is moved into 64e for now. The new logic has made
allowance for 64e, but I don't have a full environment that works well
to test it, and even booting in emulated qemu is not great for stress
testing. 64e shouldn't be too far off working with this, given a bit
more testing and auditing of the logic.
This is slightly faster on a POWER9 (page fault speed increases about
1.1%), probably due to reduced mtmsrd.
mpe: Includes fixes from Nick for _TIF_EMULATE_STACK_STORE
handling (including the fast_interrupt_return path), to remove
trace_hardirqs_on(), and fixes the interrupt-return part of the
MSR_VSX restore bug caught by tm-unavailable selftest.
mpe: Incorporate fix from Nick:
The return-to-kernel path has to replay any soft-pending interrupts if
it is returning to a context that had interrupts soft-enabled. It has
to do this carefully and avoid plain enabling interrupts if this is an
irq context, which can cause multiple nesting of interrupts on the
stack, and other unexpected issues.
The code which avoided this case got the soft-mask state wrong, and
marked interrupts as enabled before going around again to retry. This
seems to be mostly harmless except when PREEMPT=y, this calls
preempt_schedule_irq with irqs apparently enabled and runs into a BUG
in kernel/sched/core.c
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-29-npiggin@gmail.com
When local_irq_enable() finds a pending soft-masked interrupt, it
"replays" it by setting up registers like the initial interrupt entry,
then calls into the low level handler to set up an interrupt stack
frame and process the interrupt.
This is not necessary, and uses more stack than needed. The high level
interrupt handler can be called directly from C, with just pt_regs set
up on stack. This should be faster and use less stack.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-28-npiggin@gmail.com
Kernel addresses and potentially other sensitive data could be leaked
in volatile registers after a syscall.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-27-npiggin@gmail.com
System call entry and particularly exit code is beyond the limit of
what is reasonable to implement in asm.
This conversion moves all conditional branches out of the asm code,
except for the case that all GPRs should be restored at exit.
Null syscall test is about 5% faster after this patch, because the
exit work is handled under local_irq_disable, and the hard mask and
pending interrupt replay is handled after that, which avoids games
with MSR.
mpe: Includes subsequent fixes from Nick:
This fixes 4 issues caught by TM selftests. First was a tm-syscall bug
that hit due to tabort_syscall being called after interrupts were
reconciled (in a subsequent patch), which led to interrupts being
enabled before tabort_syscall was called. Rather than going through an
un-reconciling interrupts for the return, I just go back to putting
the test early in asm, the C-ification of that wasn't a big win
anyway.
Second is the syscall return _TIF_USER_WORK_MASK check would go into
an infinite loop if _TIF_RESTORE_TM became set. The asm code uses
_TIF_USER_WORK_MASK to brach to slowpath which includes
restore_tm_state.
Third is system call return was not calling restore_tm_state, I missed
this completely (alhtough it's in the return from interrupt C
conversion because when the asm syscall code encountered problems it
would branch to the interrupt return code.
Fourth is MSR_VEC missing from restore_math, which was caught by
tm-unavailable selftest taking an unexpected facility unavailable
interrupt when testing VSX unavailble exception with MSR.FP=1
MSR.VEC=1. Fourth case also has a fixup in a subsequent patch.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-26-npiggin@gmail.com
powerpc has an optimisation where interrupts avoid saving the
non-volatile (or callee saved) registers to the interrupt stack frame
if they are not required.
Two problems with this are that an interrupt does not always know
whether it will need non-volatiles; and if it does need them, they can
only be saved from the entry-scoped asm code (because we don't control
what the C compiler does with these registers).
system calls are the most difficult: some system calls always require
all registers (e.g., fork, to copy regs into the child). Sometimes
registers are only required under certain conditions (e.g., tracing,
signal delivery). These cases require ugly logic in the call
chains (e.g., ppc_fork), and require a lot of logic to be implemented
in asm.
So remove the optimisation for system calls, and always save NVGPRs on
entry. Modern high performance CPUs are not so sensitive, because the
stores are dense in cache and can be hidden by other expensive work in
the syscall path -- the null syscall selftests benchmark on POWER9 is
not slowed (124.40ns before and 123.64ns after, i.e., within the
noise).
Other interrupts retain the NVGPR optimisation for now.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-24-npiggin@gmail.com
The soft NMI handler does not reconcile interrupt state, so it should
not return via the normal ret_from_except path. Return like other NMIs,
using the EXCEPTION_RESTORE_REGS macro.
This becomes important when the scv interrupt is implemented, which
must handle soft-masked interrupts that have r13 set to something
other than the PACA -- returning to kernel in this case must restore
r13.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-23-npiggin@gmail.com
This adds IRQ_HARD_DIS to irq_happened. Although it doesn't seem to
matter much because we're not allowed to enable irqs in an NMI
handler, the soft-irq debugging code is becoming more strict about
ensuring IRQ_HARD_DIS is in sync with MSR[EE], this may help avoid
asserts or other issues.
Add a comment explaining why MCE does not have this. Early machine
check is generally much smaller and more contained code which will
explode if you look at it wrong anyway as it runs in real mode, though
there's an argument that we should do similar reconciling for the MCE
as well.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-22-npiggin@gmail.com
Apart from SRESET, MCE, and syscall (hcall variant), the SRR type
interrupts are not escalated to hypervisor mode, so are delivered to
the OS.
When running PR KVM, the OS is the hypervisor, and the guest runs with
MSR[PR]=1 (ie. usermode), so these interrupts must test if a guest was
running when interrupted. These tests are required at the real-mode
entry points because the PR KVM host runs with LPCR[AIL]=0.
In HV KVM and nested HV KVM, the guest always receives these
interrupts, so there is no need for the host to make this test. So
remove the tests if PR KVM is not configured.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-21-npiggin@gmail.com
A few of the non-standard handlers are left uncommented. Some more
description could be added to some.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-20-npiggin@gmail.com
The hdec interrupt handler is reported to sometimes fire in Linux if
KVM leaves it pending after a guest exists. This is harmless, so there
is a no-op handler for it.
The interrupt handler currently uses the regular kernel stack. Change
this to avoid touching the stack entirely.
This should be the last place where the regular Linux stack can be
accessed with asynchronous interrupts (including PMI) soft-masked.
It might be possible to take advantage of this invariant, e.g., to
context switch the kernel stack SLB entry without clearing MSR[EE].
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-17-npiggin@gmail.com
Replace IEARLY=1 and IEARLY=2 with IBRANCH_COMMON, which controls if
the entry code branches to a common handler; and IREALMODE_COMMON,
which controls whether the common handler should remain in real mode.
These special cases no longer avoid loading the SRR registers, there
is no point as most of them load the registers immediately anyway.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-14-npiggin@gmail.com
This allows more code to be moved out of unrelocated regions. The
system call KVMTEST is changed to be open-coded and remain in the
tramp area to avoid having to move it to entry_64.S. The custom nature
of the system call entry code means the hcall case can be made more
streamlined than regular interrupt handlers.
mpe: Incorporate fix from Nick:
Moving KVM test to the common entry code missed the case of HMI and
MCE, which do not do __GEN_COMMON_ENTRY (because they don't want to
switch to virt mode).
This means a MCE or HMI exception that is taken while KVM is running a
guest context will not be switched out of that context, and KVM won't
be notified. Found by running sigfuz in guest with patched host on
POWER9 DD2.3, which causes some TM related HMI interrupts (which are
expected and supposed to be handled by KVM).
This fix adds a __GEN_REALMODE_COMMON_ENTRY for those handlers to add
the KVM test. This makes them look a little more like other handlers
that all use __GEN_COMMON_ENTRY.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-13-npiggin@gmail.com
As well as moving code out of the unrelocated vectors, this allows the
masked handlers to be moved to common code, and allows the soft_nmi
handler to be generated more like a regular handler.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-12-npiggin@gmail.com
The real mode interrupt entry points currently use rfid to branch to
the common handler in virtual mode. This is a significant amount of
code, and forces other code (notably the KVM test) to live in the
real mode handler.
In the interest of minimising the amount of code that runs unrelocated
move the switch to virt mode into the common code, and do it with
mtmsrd, which avoids clobbering SRRs (although the post-KVMTEST
performance of real-mode interrupt handlers is not a big concern these
days).
This requires CTR to always be saved (real-mode needs to reach 0xc...)
but that's not a huge impact these days. It could be optimized away in
future.
mpe: Incorporate fix from Nick:
It's possible for interrupts to be replayed when TM is enabled and
suspended, for example rt_sigreturn, where the mtmsrd MSR_KERNEL in
the real-mode entry point to the common handler causes a TM Bad Thing
exception (due to attempting to clear suspended).
The fix for this is to have replay interrupts go to the _virt entry
point and skip the mtmsrd, which matches what happens before this
patch.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-11-npiggin@gmail.com
Aside from label names and BUG line numbers, the generated code change
is an additional HMI KVM handler added for the "late" KVM handler,
because early and late HMI generation is achieved by defining two
different interrupt types.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-6-npiggin@gmail.com
These don't provide a large amount of code sharing. Removing them
makes code easier to shuffle around. For example, some of the common
instructions will be moved into the common code gen macro.
No generated code change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-5-npiggin@gmail.com
The code generation macro arguments are difficult to read, and
defaults can't easily be used.
This introduces a block where parameters can be set for interrupt
handler code generation by the subsequent macros, and adds the first
generation macro for interrupt entry.
One interrupt handler is converted to the new macros to demonstrate
the change, the rest will be coverted all at once.
No generated code change.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225173541.1549955-2-npiggin@gmail.com
In restore_tm_sigcontexts() we take the trap value directly from the
user sigcontext with no checking:
err |= __get_user(regs->trap, &sc->gp_regs[PT_TRAP]);
This means we can be in the kernel with an arbitrary regs->trap value.
Although that's not immediately problematic, there is a risk we could
trigger one of the uses of CHECK_FULL_REGS():
#define CHECK_FULL_REGS(regs) BUG_ON(regs->trap & 1)
It can also cause us to unnecessarily save non-volatile GPRs again in
save_nvgprs(), which shouldn't be problematic but is still wrong.
It's also possible it could trick the syscall restart machinery, which
relies on regs->trap not being == 0xc00 (see 9a81c16b52 ("powerpc:
fix double syscall restarts")), though I haven't been able to make
that happen.
Finally it doesn't match the behaviour of the non-TM case, in
restore_sigcontext() which zeroes regs->trap.
So change restore_tm_sigcontexts() to zero regs->trap.
This was discovered while testing Nick's upcoming rewrite of the
syscall entry path. In that series the call to save_nvgprs() prior to
signal handling (do_notify_resume()) is removed, which leaves the
low-bit of regs->trap uncleared which can then trigger the FULL_REGS()
WARNs in setup_tm_sigcontexts().
Fixes: 2b0a576d15 ("powerpc: Add new transactional memory state to the signal context")
Cc: stable@vger.kernel.org # v3.9+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200401023836.3286664-1-mpe@ellerman.id.au
memcpy_mcsafe has been implemented for power machines which is used
by pmem infrastructure, so that an UE encountered during memcpy from
pmem devices would not result in panic instead a right error code
is returned. The implementation expects machine check handler to ignore
the event and set nip to continue the execution from fixup code.
Appropriate changes are already made to powernv machine check handler,
make similar changes to pseries machine check handler to ignore the
the event and set nip to continue execution at the fixup entry if we
hit UE at an instruction with a fixup entry.
while we are at it, have a common function which searches the exception
table entry and updates nip with fixup address, and any future common
changes can be made in this function that are valid for both architectures.
powernv changes are made by
commit 895e3dceeb ("powerpc/mce: Handle UE event for memcpy_mcsafe")
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Santosh S <santosh@fossix.org>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200326184916.31172-1-ganeshgr@linux.ibm.com
We can avoid the #ifdef by using IS_ENABLED() in the existing
condition check.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200313112020.28235-2-mpe@ellerman.id.au
We don't need the NULL check of np, the result is the same because the
OF helpers cope with NULL, of_node_to_nid(NULL) == NUMA_NO_NODE (-1).
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200313112020.28235-1-mpe@ellerman.id.au
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
[mpe: Drop changes to a/p/boot which doesn't use linux headers]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190812215052.71840-10-ndesaulniers@google.com
When a program check exception happens while MMU translation is
disabled, following Oops happens in kprobe_handler() in the following
code:
} else if (*addr != BREAKPOINT_INSTRUCTION) {
BUG: Unable to handle kernel data access on read at 0x0000e268
Faulting instruction address: 0xc000ec34
Oops: Kernel access of bad area, sig: 11 [#1]
BE PAGE_SIZE=16K PREEMPT CMPC885
Modules linked in:
CPU: 0 PID: 429 Comm: cat Not tainted 5.6.0-rc1-s3k-dev-00824-g84195dc6c58a #3267
NIP: c000ec34 LR: c000ecd8 CTR: c019cab8
REGS: ca4d3b58 TRAP: 0300 Not tainted (5.6.0-rc1-s3k-dev-00824-g84195dc6c58a)
MSR: 00001032 <ME,IR,DR,RI> CR: 2a4d3c52 XER: 00000000
DAR: 0000e268 DSISR: c0000000
GPR00: c000b09c ca4d3c10 c66d0620 00000000 ca4d3c60 00000000 00009032 00000000
GPR08: 00020000 00000000 c087de44 c000afe0 c66d0ad0 100d3dd6 fffffff3 00000000
GPR16: 00000000 00000041 00000000 ca4d3d70 00000000 00000000 0000416d 00000000
GPR24: 00000004 c53b6128 00000000 0000e268 00000000 c07c0000 c07bb6fc ca4d3c60
NIP [c000ec34] kprobe_handler+0x128/0x290
LR [c000ecd8] kprobe_handler+0x1cc/0x290
Call Trace:
[ca4d3c30] [c000b09c] program_check_exception+0xbc/0x6fc
[ca4d3c50] [c000e43c] ret_from_except_full+0x0/0x4
--- interrupt: 700 at 0xe268
Instruction dump:
913e0008 81220000 38600001 3929ffff 91220000 80010024 bb410008 7c0803a6
38210020 4e800020 38600000 4e800020 <813b0000> 6d2a7fe0 2f8a0008 419e0154
---[ end trace 5b9152d4cdadd06d ]---
kprobe is not prepared to handle events in real mode and functions
running in real mode should have been blacklisted, so kprobe_handler()
can safely bail out telling 'this trap is not mine' for any trap that
happened while in real-mode.
If the trap happened with MSR_IR or MSR_DR cleared, return 0
immediately.
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Fixes: 6cc89bad60 ("powerpc/kprobes: Invoke handlers directly")
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/424331e2006e7291a1bfe40e7f3fa58825f565e1.1582054578.git.christophe.leroy@c-s.fr
With the EEH early probe now being pseries specific there's no need for
eeh_ops->probe() to take a pci_dn. Instead, we can make it take a pci_dev
and use the probe function to map a pci_dev to an eeh_dev. This allows
the platform to implement it's own method for finding (or creating) an
eeh_dev for a given pci_dev which also removes a use of pci_dn in
generic EEH code.
This patch also renames eeh_device_add_late() to eeh_device_probe(). This
better reflects what it does does and removes the last vestiges of the
early/late EEH probe split.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-6-oohall@gmail.com
The eeh_ops->probe() function is called from two different contexts:
1. On pseries, where we set EEH_PROBE_MODE_DEVTREE, it's called in
eeh_add_device_early() which is supposed to run before we create
a pci_dev.
2. On PowerNV, where we set EEH_PROBE_MODE_DEV, it's called in
eeh_device_add_late() which is supposed to run *after* the
pci_dev is created.
The "early" probe is required because PAPR requires that we perform an RTAS
call to enable EEH support on a device before we start interacting with it
via config space or MMIO. This requirement doesn't exist on PowerNV and
shoehorning two completely separate initialisation paths into a common
interface just results in a convoluted code everywhere.
Additionally the early probe requires the probe function to take an pci_dn
rather than a pci_dev argument. We'd like to make pci_dn a pseries specific
data structure since there's no real requirement for them on PowerNV. To
help both goals move the early probe into the pseries containment zone
so the platform depedence is more explicit.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-5-oohall@gmail.com
This check for a missing PHB has existing in various forms since the
initial PPC64 port was upstreamed in 2002. The idea seems to be that we
need to guard against creating pci-specific data structures for the non-pci
children of a PCI device tree node (e.g. USB devices). However, we only
create pci_dn structures for DT nodes that correspond to PCI devices so
there's not much point in doing this check in the eeh_probe path.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-4-oohall@gmail.com
The pci hotplug helper (pci_hp_add_devices()) calls
eeh_add_device_tree_early() to scan the device-tree for new PCI devices and
do the early EEH probe before the device is scanned. This early probe is a
no-op in a lot of cases because:
a) The early init is only required to satisfy a PAPR requirement that EEH
be configured before we start doing config accesses. On PowerNV it is
a no-op.
b) It's a no-op for devices that have already had their eeh_dev
initialised.
There are four callers of pci_hp_add_devices():
1. arch/powerpc/kernel/eeh_driver.c
Here the hotplug helper is called when re-scanning pci_devs that
were removed during an EEH recovery pass. The EEH stat for each
removed device (the eeh_dev) is retained across a recovery pass
so the early init is a no-op in this case.
2. drivers/pci/hotplug/pnv_php.c
This is also a no-op since the PowerNV hotplug driver is, suprisingly,
PowerNV specific.
3. drivers/pci/hotplug/rpaphp_core.c
4. drivers/pci/hotplug/rpaphp_pci.c
In these two cases new devices have been hotplugged and FW has
provided new DT nodes for each. These are the only two cases where
the EEH we might have new PCI device nodes in the DT so these are
the only two cases where the early EEH probe needs to be done.
We can move the calls to eeh_add_device_tree_early() to the locations where
it's needed and remove it from the generic path. This is preparation for
making the early EEH probe pseries specific.
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-3-oohall@gmail.com
On pseries and PowerNV pcibios_bus_add_device() calls eeh_add_device_late()
so there's no need to do a separate tree traversal to bind the eeh_dev and
pci_dev together setting up the PHB at boot. As a result we can remove
eeh_add_device_tree_late().
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-2-oohall@gmail.com
Move creating the EEH specific sysfs files into eeh_add_device_late()
rather than being open-coded all over the place. Calling the function is
generally done immediately after calling eeh_add_device_late() anyway. This
is also a correctness fix since currently the sysfs files will be added
even if the EEH probe happens to fail.
Similarly, on pseries we currently add the sysfs files before calling
eeh_add_device_late(). This is flat-out broken since the sysfs files
require the pci_dev->dev.archdata.edev pointer to be set, and that is done
in eeh_add_device_late().
Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200306073904.4737-1-oohall@gmail.com
The previous commit reduced the amount of code that is run before we
setup a paca. However there are still a few remaining functions that
run with no paca, or worse, with an arbitrary value in r13 that will
be used as a paca pointer.
In particular the stack protector canary is stored in the paca, so if
stack protector is activated for any of these functions we will read
the stack canary from wherever r13 points. If r13 happens to point
outside of memory we will get a machine check / checkstop.
For example if we modify initialise_paca() to trigger stack
protection, and then boot in the mambo simulator with r13 poisoned in
skiboot before calling the kernel:
DEBUG: 19952232: (19952232): INSTRUCTION: PC=0xC0000000191FC1E8: [0x3C4C006D]: addis r2,r12,0x6D [fetch]
DEBUG: 19952236: (19952236): INSTRUCTION: PC=0xC00000001807EAD8: [0x7D8802A6]: mflr r12 [fetch]
FATAL ERROR: 19952276: (19952276): Check Stop for 0:0: Machine Check with ME bit of MSR off
DEBUG: 19952276: (19952276): INSTRUCTION: PC=0xC0000000191FCA7C: [0xE90D0CF8]: ld r8,0xCF8(r13) [Instruction Failed]
INFO: 19952276: (19952277): ** Execution stopped: Mambo Error, Machine Check Stop, **
systemsim % bt
pc: 0xC0000000191FCA7C initialise_paca+0x54
lr: 0xC0000000191FC22C early_setup+0x44
stack:0x00000000198CBED0 0x0 +0x0
stack:0x00000000198CBF00 0xC0000000191FC22C early_setup+0x44
stack:0x00000000198CBF90 0x1801C968 +0x1801C968
So annotate the relevant functions to ensure stack protection is never
enabled for them.
Fixes: 06ec27aea9 ("powerpc/64: add stack protector support")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320032116.1024773-2-mpe@ellerman.id.au
Currently we set up the paca after parsing the device tree for CPU
features. Prior to that, r13 contains random data, which means there
is random data in r13 while we're running the generic dt parsing code.
This random data varies depending on whether we boot through a vmlinux
or a zImage: for the vmlinux case it's usually around zero, but for
zImages we see random values like 912a72603d420015.
This is poor practice, and can also lead to difficult-to-debug
crashes. For example, when kcov is enabled, the kcov instrumentation
attempts to read preempt_count out of the current task, which goes via
the paca. This then crashes in the zImage case.
Similarly stack protector can cause crashes if r13 is bogus, by
reading from the stack canary in the paca.
To resolve this:
- move the paca setup to before the CPU feature parsing.
- because we no longer have access to CPU feature flags in paca
setup, change the HV feature test in the paca setup path to consider
the actual value of the MSR rather than the CPU feature.
Translations get switched on once we leave early_setup, so I think
we'd already catch any other cases where the paca or task aren't set
up.
Boot tested on a P9 guest and host.
Fixes: fb0b0a73b2 ("powerpc: Enable kcov")
Fixes: 06ec27aea9 ("powerpc/64: add stack protector support")
Cc: stable@vger.kernel.org # v4.20+
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Daniel Axtens <dja@axtens.net>
[mpe: Reword comments & change log a bit to mention stack protector]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200320032116.1024773-1-mpe@ellerman.id.au
Reorder Linux PTE bits to (almost) match Hash PTE bits.
RW Kernel : PP = 00
RO Kernel : PP = 00
RW User : PP = 01
RO User : PP = 11
So naturally, we should have
_PAGE_USER = 0x001
_PAGE_RW = 0x002
Today 0x001 and 0x002 and _PAGE_PRESENT and _PAGE_HASHPTE which
both are software only bits.
Switch _PAGE_USER and _PAGE_PRESET
Switch _PAGE_RW and _PAGE_HASHPTE
This allows to remove a few insns.
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/c4d6c18a7f8d9d3b899bc492f55fbc40ef38896a.1583861325.git.christophe.leroy@c-s.fr
At the time being we have something like
if (something) {
p = get();
if (p) {
if (something_wrong)
goto out;
...
return;
} else if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
p = get();
if (!p) {
if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
This is similar to
p = get();
if (!p) {
if (a != b) {
if (some_error)
goto out;
...
}
goto out;
}
if (something) {
if (something_wrong)
goto out;
...
return;
}
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[mpe: Reflow the comment that was moved]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/07a17425743600460ce35fa9432d42487a825583.1582099499.git.christophe.leroy@c-s.fr
We currently have two section mismatch warnings:
The function __boot_from_prom() references
the function __init prom_init().
The function start_here_common() references
the function __init start_kernel().
The warnings are correct, we do have branches from non-init code into
init code, which is freed after boot. But we don't expect to ever
execute any of that early boot code after boot, if we did that would
be a bug. In particular calling into OF after boot would be fatal
because OF is no longer resident.
So for now fix the warnings by marking the relevant functions as
__REF, which puts them in the ".ref.text" section.
This causes some reordering of the functions in the final link:
@@ -217,10 +217,9 @@
c00000000000b088 t generic_secondary_common_init
c00000000000b124 t __mmu_off
c00000000000b14c t __start_initialization_multiplatform
-c00000000000b1ac t __boot_from_prom
-c00000000000b1ec t __after_prom_start
-c00000000000b260 t p_end
-c00000000000b27c T copy_and_flush
+c00000000000b1ac t __after_prom_start
+c00000000000b220 t p_end
+c00000000000b23c T copy_and_flush
c00000000000b300 T __secondary_start
c00000000000b300 t copy_to_here
c00000000000b344 t start_secondary_prolog
@@ -228,8 +227,9 @@
c00000000000b36c t enable_64b_mode
c00000000000b388 T relative_toc
c00000000000b3a8 t p_toc
-c00000000000b3b0 t start_here_common
-c00000000000b3d0 t start_here_multiplatform
+c00000000000b3b0 t __boot_from_prom
+c00000000000b3f0 t start_here_multiplatform
+c00000000000b480 t start_here_common
c00000000000b880 T system_call_common
c00000000000b974 t system_call
c00000000000b9dc t system_call_exit
In particular __boot_from_prom moves after copy_to_here, which means
it's not copied to zero in the first stage of copy of the kernel to
zero.
But that's OK, because we only call __boot_from_prom before we do the
copy, so it makes no difference when it's copied. The call sequence
is:
__start
-> __start_initialization_multiplatform
-> __boot_from_prom
-> __start
-> __start_initialization_multiplatform
-> __after_prom_start
-> copy_and_flush
-> copy_and_flush (relocated to 0)
-> start_here_multiplatform
-> early_setup
Reported-by: Mauricio Faria de Oliveira <mauricfo@linux.ibm.com>
Reported-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225031328.14676-1-mpe@ellerman.id.au
The "os-term" RTAS calls has one argument with a message address of OS
termination cause. rtas_os_term() already passes it but the recently
added prom_init's version of that missed it; it also does not fill
args correctly.
This passes the message address and initializes the number of arguments.
Fixes: 6a9c930bd7 ("powerpc/prom_init: Add the ESM call to prom_init")
Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200312074404.87293-1-aik@ozlabs.ru
Simplify gen_btf logic to make it work with llvm-objcopy. The existing
'file format' and 'architecture' parsing logic is brittle and does not
work with llvm-objcopy/llvm-objdump.
'file format' output of llvm-objdump>=11 will match GNU objdump, but
'architecture' (bfdarch) may not.
.BTF in .tmp_vmlinux.btf is non-SHF_ALLOC. Add the SHF_ALLOC flag
because it is part of vmlinux image used for introspection. C code
can reference the section via linker script defined __start_BTF and
__stop_BTF. This fixes a small problem that previous .BTF had the
SHF_WRITE flag (objcopy -I binary -O elf* synthesized .data).
Additionally, `objcopy -I binary` synthesized symbols
_binary__btf_vmlinux_bin_start and _binary__btf_vmlinux_bin_stop (not
used elsewhere) are replaced with more commonplace __start_BTF and
__stop_BTF.
Add 2>/dev/null because GNU objcopy (but not llvm-objcopy) warns
"empty loadable segment detected at vaddr=0xffffffff81000000, is this intentional?"
We use a dd command to change the e_type field in the ELF header from
ET_EXEC to ET_REL so that lld will accept .btf.vmlinux.bin.o. Accepting
ET_EXEC as an input file is an extremely rare GNU ld feature that lld
does not intend to support, because this is error-prone.
The output section description .BTF in include/asm-generic/vmlinux.lds.h
avoids potential subtle orphan section placement issues and suppresses
--orphan-handling=warn warnings.
Fixes: df786c9b94 ("bpf: Force .BTF section start to zero when dumping from vmlinux")
Fixes: cb0cc635c7 ("powerpc: Include .BTF section")
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Stanislav Fomichev <sdf@google.com>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Link: https://github.com/ClangBuiltLinux/linux/issues/871
Link: https://lore.kernel.org/bpf/20200318222746.173648-1-maskray@google.com
The original 2005 patch that introduced the powerpc vdso, pre-git
("ppc64: Implement a vDSO and use it for signal trampoline") notes that:
... symbols exposed by the vDSO aren't "normal" function symbols, apps
can't be expected to link against them directly, the vDSO's are both
seen as if they were linked at 0 and the symbols just contain offsets
to the various functions. This is done on purpose to avoid a
relocation step (ppc64 functions normally have descriptors with abs
addresses in them). When glibc uses those functions, it's expected to
use it's own trampolines that know how to reach them.
Despite that explanation, there remains dead #ifdef
VDS64_HAS_DESCRIPTORS code-blocks that provide alternate function
definitions that setup function descriptors.
Since VDS64_HAS_DESCRIPTORS has been unused for all these years, we
might as well finally remove it from the codebase.
Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200224211848.26087-1-joe.lawrence@redhat.com
With commit ("powerpc/numa: Early request for home node associativity"),
commit 2ea6263068 ("powerpc/topology: Get topology for shared
processors at boot") which was requesting home node associativity
becomes redundant.
Hence remove the late request for home node associativity.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reported-by: Abdul Haleem <abdhalee@linux.vnet.ibm.com>
Reviewed-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200129135301.24739-6-srikar@linux.vnet.ibm.com
package_id is to match cores that are part of the same chip. On
PowerNV machines, package_id defaults to chip_id. However ibm,chip_id
property is not present in device-tree of PowerVM LPARs. Hence lscpu
output shows one core per socket and multiple cores.
To overcome this, use nid as the package_id on PowerVM LPARs.
Before the patch:
Architecture: ppc64le
Byte Order: Little Endian
CPU(s): 128
On-line CPU(s) list: 0-127
Thread(s) per core: 8
Core(s) per socket: 1 <----------------------
Socket(s): 16 <----------------------
NUMA node(s): 2
Model: 2.2 (pvr 004e 0202)
Model name: POWER9 (architected), altivec supported
Hypervisor vendor: pHyp
Virtualization type: para
L1d cache: 32K
L1i cache: 32K
L2 cache: 512K
L3 cache: 10240K
NUMA node0 CPU(s): 0-63
NUMA node1 CPU(s): 64-127
#
# cat /sys/devices/system/cpu/cpu0/topology/physical_package_id
-1
After the patch:
Architecture: ppc64le
Byte Order: Little Endian
CPU(s): 128
On-line CPU(s) list: 0-127
Thread(s) per core: 8 <---------------------
Core(s) per socket: 8 <---------------------
Socket(s): 2
NUMA node(s): 2
Model: 2.2 (pvr 004e 0202)
Model name: POWER9 (architected), altivec supported
Hypervisor vendor: pHyp
Virtualization type: para
L1d cache: 32K
L1i cache: 32K
L2 cache: 512K
L3 cache: 10240K
NUMA node0 CPU(s): 0-63
NUMA node1 CPU(s): 64-127
#
# cat /sys/devices/system/cpu/cpu0/topology/physical_package_id
0
Now lscpu output is more in line with the system configuration.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
[mpe: Use pkg_id instead of ppid, tweak change log and comment]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200129135121.24617-1-srikar@linux.vnet.ibm.com
Until commit 7306e83ccf ("powerpc: Don't use CURRENT_THREAD_INFO to
find the stack"), the current stack base address was obtained by
calling current_thread_info(). That inline function was simply masking
out the value of r1.
In that commit, it was changed to using current_stack_pointer() (since
renamed current_stack_frame()), which is a heavier function as it is
an outline assembly function which cannot be inlined and which reads
the content of the stack at 0(r1).
Convert to using current_stack_pointer for geting r1 and masking out
its value to obtain the base address of the stack pointer as before.
Fixes: 7306e83ccf ("powerpc: Don't use CURRENT_THREAD_INFO to find the stack")
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/20200220115141.2707-5-mpe@ellerman.id.au
Instead of #ifdef, use IS_ENABLED(CONFIG_DEBUG_STACKOVERFLOW).
This enable GCC to check for code validity even when the option
is not selected.
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/20200220115141.2707-4-mpe@ellerman.id.au
The purpose of check_stack_overflow() is to verify that the stack has
not overflowed.
To really know whether the stack pointer is still within boundaries,
the check must be done directly on the value of r1.
So use current_stack_pointer, which returns the current value of r1,
rather than current_stack_frame() which causes a frame to be created
and then returns that value.
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/20200220115141.2707-3-mpe@ellerman.id.au
current_stack_pointer(), which was called __get_SP(), used to just
return the value in r1.
But that caused problems in some cases, so it was turned into a
function in commit bfe9a2cfe9 ("powerpc: Reimplement __get_SP() as a
function not a define").
Because it's a function in a separate compilation unit to all its
callers, it has the effect of causing a stack frame to be created, and
then returns the address of that frame. This is good in some cases
like those described in the above commit, but in other cases it's
overkill, we just need to know what stack page we're on.
On some other arches current_stack_pointer is just a register global
giving the stack pointer, and we'd like to do that too. So rename our
current_stack_pointer() to current_stack_frame() to make that
possible.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Link: https://lore.kernel.org/r/20200220115141.2707-1-mpe@ellerman.id.au
Many of the performance monitoring unit (PMU) SPRs are
exposed in the sysfs. This may not be a desirable since
"perf" API is the primary interface to program PMU and
collect counter data in the system. But that said, we
cant remove these sysfs files since we dont whether
anyone/anything is using them.
So the patch adds a new CONFIG option 'CONFIG_PMU_SYSFS'
(user selectable) to be used in sysfs file creation for
PMU SPRs. New option by default is disabled, but can be
enabled if user needs it.
Tested this patch behaviour in powernv and pseries machines.
Patch is also tested for pmac32_defconfig.
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Tested-by: Nageswara R Sastry <nasastry@in.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200214080606.26872-2-kjain@linux.ibm.com
An attempt to refactor the current sysfs.c file.
To start with a big chuck of macro #defines and dscr
functions are moved to start of the file. Secondly,
HAS_ #define macros are cleanup based on CONFIG_ options
Finally new HAS_ macro added:
1. HAS_PPC_PA6T (for PA6T) to separate out non-PMU SPRs.
2. HAS_PPC_PMC56 to separate out PMC SPR's from HAS_PPC_PMC_CLASSIC
which come under CONFIG_PPC64.
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200214080606.26872-1-kjain@linux.ibm.com
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.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200209105901.1620958-1-gregkh@linuxfoundation.org
PowerVM systems running compatibility mode on a few Power8 revisions are
still vulnerable to the hardware defect that loses PMU exceptions arriving
prior to a context switch.
The software fix for this issue is enabled through the CPU_FTR_PMAO_BUG
cpu_feature bit, nevertheless this bit also needs to be set for PowerVM
compatibility mode systems.
Fixes: 68f2f0d431 ("powerpc: Add a cpu feature CPU_FTR_PMAO_BUG")
Signed-off-by: Desnes A. Nunes do Rosario <desnesn@linux.ibm.com>
Reviewed-by: Leonardo Bras <leonardo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200227134715.9715-1-desnesn@linux.ibm.com
Since commit b86fb88855 ("powerpc/32: implement fast entry for
syscalls on non BOOKE") and commit 1a4b739bbb ("powerpc/32:
implement fast entry for syscalls on BOOKE"), syscalls don't
use the exception entry path anymore. It is therefore pointless
to restore r0 and r6-r8 after calling trace_hardirqs_off().
In the meantime, drop the '2:' label which is unused and misleading.
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/d2c6dc65d27e83964eb05f16a126161ab6455eea.1578388585.git.christophe.leroy@c-s.fr
Selecting CONFIG_DEBUG_INFO_BTF results in the below warning from ld:
ld: warning: orphan section `.BTF' from `.btf.vmlinux.bin.o' being placed in section `.BTF'
Include .BTF section in vmlinux explicitly to fix the same.
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200220113132.857132-1-naveen.n.rao@linux.vnet.ibm.com
DAR is set to the first byte of overlap between actual access and
watched range at DSI on Book3S processor. But actual access range
might or might not be within user asked range. So for Book3S, it
must not call dar_within_range().
This revert portion of commit 39413ae009 ("powerpc/hw_breakpoints:
Rewrite 8xx breakpoints to allow any address range size.").
Before patch:
# ./tools/testing/selftests/powerpc/ptrace/perf-hwbreak
...
TESTED: No overlap
FAILED: Partial overlap: 0 != 2
TESTED: Partial overlap
TESTED: No overlap
FAILED: Full overlap: 0 != 2
failure: perf_hwbreak
After patch:
TESTED: No overlap
TESTED: Partial overlap
TESTED: Partial overlap
TESTED: No overlap
TESTED: Full overlap
success: perf_hwbreak
Fixes: 39413ae009 ("powerpc/hw_breakpoints: Rewrite 8xx breakpoints to allow any address range size.")
Reported-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200222082049.330435-1-ravi.bangoria@linux.ibm.com
CR0 can be saved later, and CTR can also be used for saving.
Keep SRR1 in r9 and stash SRR0 in CTR, this avoids using thread_struct
in memory for that.
Saves 3 cycles (ie 1%) in null_syscall selftest on 8xx.
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/b94c3bc03bac9431fec2dadb686384c481889422.1580470483.git.christophe.leroy@c-s.fr
Since commit b86fb88855 ("powerpc/32: implement fast entry for
syscalls on non BOOKE") and commit 1a4b739bbb ("powerpc/32:
implement fast entry for syscalls on BOOKE"), syscalls from
kernel are unexpected and can have catastrophic consequences
as it will destroy the kernel stack.
Test MSR_PR on syscall entry. In case syscall is from kernel,
emit a warning and return ENOSYS error.
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/8ee3bdbbdfdfc64ca7001e90c43b2aee6f333578.1580470482.git.christophe.leroy@c-s.fr
Add a sys interface to allow querying the memory reserved by FADump for
saving the crash dump.
Also added Documentation/ABI for the new sysfs file.
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191211160910.21656-7-sourabhjain@linux.ibm.com
As the number of FADump sysfs files increases it is hard to manage all
of them inside /sys/kernel directory. It's better to have all the
FADump related sysfs files in a dedicated directory
/sys/kernel/fadump. But in order to maintain backward compatibility a
symlink has been added for every sysfs that has moved to new location.
As the FADump sysfs files are now part of a dedicated directory there
is no need to prefix their name with fadump_, hence sysfs file names
are also updated. For example fadump_enabled sysfs file is now
referred as enabled.
Also consolidate ABI documentation for all the FADump sysfs files in a
single file Documentation/ABI/testing/sysfs-kernel-fadump.
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Tested-by: Michal Suchanek <msuchanek@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20191211160910.21656-4-sourabhjain@linux.ibm.com
power_save_ppc32_restore() is called during exception entry, before
re-enabling the MMU. It substracts KERNELBASE from the address
of nap_save_msscr0 to access it.
With CONFIG_VMAP_STACK enabled, data MMU translation has already been
re-enabled, so power_save_ppc32_restore() has to access
nap_save_msscr0 by its virtual address.
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Fixes: cd08f109e2 ("powerpc/32s: Enable CONFIG_VMAP_STACK")
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/7bce32ccbab3ba3e3e0f27da6961bf6313df97ed.1581663140.git.christophe.leroy@c-s.fr
hash_page() needs to read page tables from kernel memory. When entire
kernel memory is mapped by BATs, which is normally the case when
CONFIG_STRICT_KERNEL_RWX is not set, it works even if the page hosting
the page table is not referenced in the MMU hash table.
However, if the page where the page table resides is not covered by
a BAT, a DSI fault can be encountered from hash_page(), and it loops
forever. This can happen when CONFIG_STRICT_KERNEL_RWX is selected
and the alignment of the different regions is too small to allow
covering the entire memory with BATs. This also happens when
CONFIG_DEBUG_PAGEALLOC is selected or when booting with 'nobats'
flag.
Also, if the page containing the kernel stack is not present in the
MMU hash table, registers cannot be saved and a recursive DSI fault
is encountered.
To allow hash_page() to properly do its job at all time and load the
MMU hash table whenever needed, it must run with data MMU disabled.
This means it must be called before re-enabling data MMU. To allow
this, registers clobbered by hash_page() and create_hpte() have to
be saved in the thread struct together with SRR0, SSR1, DAR and DSISR.
It is also necessary to ensure that DSI prolog doesn't overwrite
regs saved by prolog of the current running exception. That means:
- DSI can only use SPRN_SPRG_SCRATCH0
- Exceptions must free SPRN_SPRG_SCRATCH0 before writing to the stack.
This also fixes the Oops reported by Erhard when create_hpte() is
called by add_hash_page().
Due to prolog size increase, a few more exceptions had to get split
in two parts.
Fixes: cd08f109e2 ("powerpc/32s: Enable CONFIG_VMAP_STACK")
Reported-by: Erhard F. <erhard_f@mailbox.org>
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Tested-by: Erhard F. <erhard_f@mailbox.org>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206501
Link: https://lore.kernel.org/r/64a4aa44686e9fd4b01333401367029771d9b231.1581761633.git.christophe.leroy@c-s.fr
After a treclaim, we expect to be in non-transactional state. If we
don't clear the current thread's MSR[TS] before we get preempted, then
tm_recheckpoint_new_task() will recheckpoint and we get rescheduled in
suspended transaction state.
When handling a signal caught in transactional state,
handle_rt_signal64() calls get_tm_stackpointer() that treclaims the
transaction using tm_reclaim_current() but without clearing the
thread's MSR[TS]. This can cause the TM Bad Thing exception below if
later we pagefault and get preempted trying to access the user's
sigframe, using __put_user(). Afterwards, when we are rescheduled back
into do_page_fault() (but now in suspended state since the thread's
MSR[TS] was not cleared), upon executing 'rfid' after completion of
the page fault handling, the exception is raised because a transition
from suspended to non-transactional state is invalid.
Unexpected TM Bad Thing exception at c00000000000de44 (msr 0x8000000302a03031) tm_scratch=800000010280b033
Oops: Unrecoverable exception, sig: 6 [#1]
LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
CPU: 25 PID: 15547 Comm: a.out Not tainted 5.4.0-rc2 #32
NIP: c00000000000de44 LR: c000000000034728 CTR: 0000000000000000
REGS: c00000003fe7bd70 TRAP: 0700 Not tainted (5.4.0-rc2)
MSR: 8000000302a03031 <SF,VEC,VSX,FP,ME,IR,DR,LE,TM[SE]> CR: 44000884 XER: 00000000
CFAR: c00000000000dda4 IRQMASK: 0
PACATMSCRATCH: 800000010280b033
GPR00: c000000000034728 c000000f65a17c80 c000000001662800 00007fffacf3fd78
GPR04: 0000000000001000 0000000000001000 0000000000000000 c000000f611f8af0
GPR08: 0000000000000000 0000000078006001 0000000000000000 000c000000000000
GPR12: c000000f611f84b0 c00000003ffcb200 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000 0000000000000000 c000000f611f8140
GPR24: 0000000000000000 00007fffacf3fd68 c000000f65a17d90 c000000f611f7800
GPR28: c000000f65a17e90 c000000f65a17e90 c000000001685e18 00007fffacf3f000
NIP [c00000000000de44] fast_exception_return+0xf4/0x1b0
LR [c000000000034728] handle_rt_signal64+0x78/0xc50
Call Trace:
[c000000f65a17c80] [c000000000034710] handle_rt_signal64+0x60/0xc50 (unreliable)
[c000000f65a17d30] [c000000000023640] do_notify_resume+0x330/0x460
[c000000f65a17e20] [c00000000000dcc4] ret_from_except_lite+0x70/0x74
Instruction dump:
7c4ff120 e8410170 7c5a03a6 38400000 f8410060 e8010070 e8410080 e8610088
60000000 60000000 e8810090 e8210078 <4c000024> 48000000 e8610178 88ed0989
---[ end trace 93094aa44b442f87 ]---
The simplified sequence of events that triggers the above exception is:
... # userspace in NON-TRANSACTIONAL state
tbegin # userspace in TRANSACTIONAL state
signal delivery # kernelspace in SUSPENDED state
handle_rt_signal64()
get_tm_stackpointer()
treclaim # kernelspace in NON-TRANSACTIONAL state
__put_user()
page fault happens. We will never get back here because of the TM Bad Thing exception.
page fault handling kicks in and we voluntarily preempt ourselves
do_page_fault()
__schedule()
__switch_to(other_task)
our task is rescheduled and we recheckpoint because the thread's MSR[TS] was not cleared
__switch_to(our_task)
switch_to_tm()
tm_recheckpoint_new_task()
trechkpt # kernelspace in SUSPENDED state
The page fault handling resumes, but now we are in suspended transaction state
do_page_fault() completes
rfid <----- trying to get back where the page fault happened (we were non-transactional back then)
TM Bad Thing # illegal transition from suspended to non-transactional
This patch fixes that issue by clearing the current thread's MSR[TS]
just after treclaim in get_tm_stackpointer() so that we stay in
non-transactional state in case we are preempted. In order to make
treclaim and clearing the thread's MSR[TS] atomic from a preemption
perspective when CONFIG_PREEMPT is set, preempt_disable/enable() is
used. It's also necessary to save the previous value of the thread's
MSR before get_tm_stackpointer() is called so that it can be exposed
to the signal handler later in setup_tm_sigcontexts() to inform the
userspace MSR at the moment of the signal delivery.
Found with tm-signal-context-force-tm kernel selftest.
Fixes: 2b0a576d15 ("powerpc: Add new transactional memory state to the signal context")
Cc: stable@vger.kernel.org # v3.9
Signed-off-by: Gustavo Luiz Duarte <gustavold@linux.ibm.com>
Acked-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200211033831.11165-1-gustavold@linux.ibm.com
In ITLB miss handled the line supposed to clear bits 20-23 on the L2
ITLB entry is buggy and does indeed nothing, leading to undefined
value which could allow execution when it shouldn't.
Properly do the clearing with the relevant instruction.
Fixes: 74fabcadfd ("powerpc/8xx: don't use r12/SPRN_SPRG_SCRATCH2 in TLB Miss handlers")
Cc: stable@vger.kernel.org # v5.0+
Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Leonardo Bras <leonardo@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4f70c2778163affce8508a210f65d140e84524b4.1581272050.git.christophe.leroy@c-s.fr
Recovering a dead PHB can currently cause a deadlock as the PCI
rescan/remove lock is taken twice.
This is caused as part of an existing bug in
eeh_handle_special_event(). The pe is processed while traversing the
PHBs even though the pe is unrelated to the loop. This causes the pe
to be, incorrectly, processed more than once.
Untangling this section can move the pe processing out of the loop and
also outside the locked section, correcting both problems.
Fixes: 2e25505147 ("powerpc/eeh: Fix crash when edev->pdev changes")
Cc: stable@vger.kernel.org # 5.4+
Signed-off-by: Sam Bobroff <sbobroff@linux.ibm.com>
Reviewed-by: Frederic Barrat <fbarrat@linux.ibm.com>
Tested-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/0547e82dbf90ee0729a2979a8cac5c91665c621f.1581051445.git.sbobroff@linux.ibm.com
Let's use the struct of_pci_range.flags field instead so we can remove
the pci_space field.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Rob Herring <robh@kernel.org>
