Commit Graph

20156 Commits

Author SHA1 Message Date
Nicholas Piggin
391e941b89 powerpc/64s/exception: use common macro for windup
No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 21:39:48 +10:00
Nicholas Piggin
b113c08341 powerpc/64s/exception: shuffle windup code around
Restore all SPRs and CR up-front, these are longer latency
instructions. Move register restore around to maximise pairs of
adjacent loads (e.g., restore r0 next to r1).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 21:39:48 +10:00
Nicholas Piggin
67d4160a61 powerpc/64s/exception: simplify hmi windup code
Duplicate the hmi windup code for both cases, rather than to put a
special case branch in the middle of it. Remove unused label. This
helps with later code consolidation.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 21:39:48 +10:00
Nicholas Piggin
ad73d8d4f4 powerpc/64s/exception: move machine check windup in_mce handling
Move in_mce decrement earlier before registers are restored (but
still after RI=0). This helps with later consolidation.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 21:39:48 +10:00
Nicholas Piggin
9592b29a9c powerpc/64s/exception: windup use r9 consistently to restore SPRs
Trivial code change, r3->r9.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 21:39:48 +10:00
Nicholas Piggin
fbc50063a2 powerpc/64s/exception: mtmsrd L=1 cleanup
All supported 64s CPUs support mtmsrd L=1 instruction, so a cleanup
can be made in sreset and mce handlers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 21:39:48 +10:00
Nicholas Piggin
63d60d0c69 powerpc/64s/exception: avoid SPR RAW scoreboard stall in real mode entry
Move SPR reads ahead of writes. Real mode entry that is not a KVM
guest is rare these days, but bad practice propagates.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 21:39:48 +10:00
Nicholas Piggin
b0b2a93da4 powerpc/64s/exception: clean up system call entry
syscall / hcall entry unnecessarily differs between KVM and non-KVM
builds. Move the SMT priority instruction to the same location
(after INTERRUPT_TO_KERNEL).

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 21:39:48 +10:00
Nicholas Piggin
1582009113 powerpc/64s/exception: move paca save area offsets into exception-64s.S
No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 21:39:20 +10:00
Nicholas Piggin
d064151fd3 powerpc/64s/exception: remove pointless EXCEPTION_PROLOG macro indirection
No generated code change. Final vmlinux is changed only due to change
in bug table line numbers.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 21:38:28 +10:00
Nicholas Piggin
f3c8b6c63e powerpc/64s/exception: generate regs clear instructions using .rept
No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:43 +10:00
Nicholas Piggin
bf66e3c4cf powerpc/64s/exception: fix indenting irregularities
Generally, macros that result in instructions being expanded are
indented by a tab, and those that don't have no indent. Fix the
obvious cases that go contrary to style.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:43 +10:00
Nicholas Piggin
1b4d4a7933 powerpc/64s/exception: use a gas macro for system call handler code
No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:43 +10:00
Nicholas Piggin
f945478d5c powerpc/64s/exception: remove unused BRANCH_TO_COMMON
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:43 +10:00
Nicholas Piggin
64e413515c powerpc/64s/exception: remove __BRANCH_TO_KVM
No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
a0502434bb powerpc/64s/exception: move head-64.h code to exception-64s.S where it is used
No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
12a0480990 powerpc/64s/exception: move exception-64s.h code to exception-64s.S where it is used
No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
f1ff37e8f2 powerpc/64s/exception: move KVM related code together
No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
6d18f29c33 powerpc/64s/exception: remove STD_EXCEPTION_COMMON variants
These are only called in one place each.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
f0ac44788e powerpc/64s/exception: move EXCEPTION_PROLOG_2* to a more logical place
No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
80bd9177de powerpc/64s/exception: improve 0x500 handler code
After the previous cleanup, it becomes possible to consolidate some
common code outside the runtime alternate patching. Also remove
unused labels.

This results in some code change, but unchanged runtime instruction
sequence.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
fc557537f2 powerpc/64s/exception: unwind exception-64s.h macros
Many of these macros just specify 1-4 lines which are only called a
few times each at most, and often just once. Remove this indirection.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
47169fba3a powerpc/64s/exception: Move EXCEPTION_COMMON additions into callers
More cases of code insertion via macros that does not add a great
deal. All the additions have to be specified in the macro arguments,
so they can just as well go after the macro.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
c06075f3d3 powerpc/64s/exception: Move EXCEPTION_COMMON handler and return branches into callers
The aim is to reduce the amount of indirection it takes to get through
the exception handler macros, particularly where it provides little
code sharing.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
5dba1d50ba powerpc/64s/exception: Make EXCEPTION_PROLOG_0 a gas macro for consistency with others
No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
c0c6cd156c powerpc/64s/exception: KVM handler can set the HSRR trap bit
Move the KVM trap HSRR bit into the KVM handler, which can be
conditionally applied when hsrr parameter is set.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
17bdc064a1 powerpc/64s/exception: merge KVM handler and skip variants
Conditionally expand the skip case if it is specified.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
fa4cf6b703 powerpc/64s/exception: consolidate maskable and non-maskable prologs
Conditionally expand the soft-masking test if a mask is passed in.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:42 +10:00
Nicholas Piggin
a7c1ca19c2 powerpc/64s/exception: remove the "extra" macro parameter
Rather than pass in the soft-masking and KVM tests via macro that is
passed to another macro to expand it, switch to usig gas macros and
conditionally expand the soft-masking and KVM tests.

The system reset with its idle test is open coded as it is a one-off.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:41 +10:00
Nicholas Piggin
8f528359ef powerpc/64s/exception: fix sreset KVM test code
The sreset handler KVM test theoretically should not depend on P7.
In practice KVM now only supports P7 and up so no real bug fix, but
this change is made now so the quirk is not propagated through
cleanup patches.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:41 +10:00
Nicholas Piggin
2d046308d0 powerpc/64s/exception: move and tidy EXCEPTION_PROLOG_2 variants
- Re-name the macros to _REAL and _VIRT suffixes rather than no and
  _RELON suffix.

- Move the macro definitions together in the file.

- Move RELOCATABLE ifdef inside the _VIRT macro.

Further consolidation between variants does not buy much here.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:41 +10:00
Nicholas Piggin
bd7b6d1334 powerpc/64s/exception: consolidate EXCEPTION_PROLOG_2 with _NORI variant
Switch to a gas macro that conditionally expands the RI clearing
instruction.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:24:41 +10:00
Nicholas Piggin
4508a74a63 powerpc/64s/exception: remove H concatenation for EXC_HV variants
Replace all instances of this with gas macros that test the hsrr
parameter and use the appropriate register names / labels.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
[mpe: Remove extraneous 2nd check for 0xea0 in SOFTEN_TEST]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 20:23:51 +10:00
Michael Ellerman
1efd8caa9a powerpc/64s/exception: Remove unused SOFTEN_VALUE_0x980
Remove SOFTEN_VALUE_0x980, it's been unused since commit
dabe859ec6 ("powerpc: Give hypervisor decrementer interrupts their
own handler") (Sep 2012).

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-02 18:21:59 +10:00
Nicholas Piggin
4b1f5ccc7c powerpc/64s/exception: fix line wrap and semicolon inconsistencies in macros
By convention, all lines should be separated by a semicolons. Last line
should have neither semicolon or line wrap.

No generated code change.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:55 +10:00
Christoph Hellwig
452d23c0f6 powerpc/powernv: remove the unused vas_win_paste_addr and vas_win_id functions
These two function have never been used anywhere in the kernel tree
since they were added to the kernel.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:55 +10:00
Christoph Hellwig
7eb3cf7619 powerpc/powernv: remove unused NPU DMA code
None of these routines were ever used anywhere in the kernel tree
since they were added to the kernel.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:55 +10:00
Christoph Hellwig
c498a4f9a7 powerpc/powernv: remove the unused tunneling exports
These have been unused anywhere in the kernel tree ever since they've
been added to the kernel.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:55 +10:00
Christoph Hellwig
6398261866 powerpc/powernv: remove the unused pnv_pci_set_p2p function
This function has never been used anywhere in the kernel tree since it
was added to the tree.  We also now have proper PCIe P2P APIs in the core
kernel, and any new P2P support should be using those.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:55 +10:00
Naveen N. Rao
aaf06665f7 powerpc/xmon: Fix disabling tracing while in xmon
Commit ed49f7fd64 ("powerpc/xmon: Disable tracing when entering
xmon") added code to disable recording trace entries while in xmon. The
commit introduced a variable 'tracing_enabled' to record if tracing was
enabled on xmon entry, and used this to conditionally enable tracing
during exit from xmon.

However, we are not checking the value of 'fromipi' variable in
xmon_core() when setting 'tracing_enabled'. Due to this, when secondary
cpus enter xmon, they will see tracing as being disabled already and
tracing won't be re-enabled on exit. Fix the same.

Fixes: ed49f7fd64 ("powerpc/xmon: Disable tracing when entering xmon")
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:55 +10:00
Qian Cai
04db3ede40 powerpc/cacheflush: fix variable set but not used
The powerpc's flush_cache_vmap() is defined as a macro and never use
both of its arguments, so it will generate a compilation warning,

lib/ioremap.c: In function 'ioremap_page_range':
lib/ioremap.c:203:16: warning: variable 'start' set but not used
[-Wunused-but-set-variable]

Fix it by making it an inline function.

Signed-off-by: Qian Cai <cai@lca.pw>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:55 +10:00
Qian Cai
3becd11dff powerpc/eeh_cache: fix a W=1 kernel-doc warning
The opening comment mark "/**" is reserved for kernel-doc comments, so
it will generate a warning with "make W=1".

arch/powerpc/kernel/eeh_cache.c:37: warning: cannot understand function
prototype: 'struct pci_io_addr_range

Since this is not a kernel-doc for the struct below, but rather an
overview of this source eeh_cache.c, just use the free-form comments
kernel-doc syntax instead.

Signed-off-by: Qian Cai <cai@lca.pw>
Acked-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:54 +10:00
Christophe Leroy
f079bb3c5f powerpc/ftrace: Enable C Version of recordmcount
Selects HAVE_C_RECORDMCOUNT to use the C version of the recordmcount
intead of the old Perl Version of recordmcount.

This should improve build time. It also seems like the old Perl Version
misses some calls to _mcount that the C version finds.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:54 +10:00
Nathan Lynch
9fb603050f powerpc/rtas: retry when cpu offline races with suspend/migration
The protocol for suspending or migrating an LPAR requires all present
processor threads to enter H_JOIN. So if we have threads offline, we
have to temporarily bring them up. This can race with administrator
actions such as SMT state changes. As of dfd718a2ed ("powerpc/rtas:
Fix a potential race between CPU-Offline & Migration"),
rtas_ibm_suspend_me() accounts for this, but errors out with -EBUSY
for what almost certainly is a transient condition in any reasonable
scenario.

Callers of rtas_ibm_suspend_me() already retry when -EAGAIN is
returned, and it is typical during a migration for that to happen
repeatedly for several minutes polling the H_VASI_STATE hcall result
before proceeding to the next stage.

So return -EAGAIN instead of -EBUSY when this race is
encountered. Additionally: logging this event is still appropriate but
use pr_info instead of pr_err; and remove use of unlikely() while here
as this is not a hot path at all.

Fixes: dfd718a2ed ("powerpc/rtas: Fix a potential race between CPU-Offline & Migration")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-07-01 16:26:54 +10:00
Michael Ellerman
8b8dc69514 Merge branch 'fixes' into next
Merge our fixes branch into next, this brings in a number of commits
that fix bugs we don't want to hit in next, in particular the fix for
CVE-2019-12817.
2019-07-01 14:04:39 +10:00
Michael Ellerman
b7cbb52401 powerpc fixes for 5.2 #6
One fix for a bug in our context id handling on 64-bit hash CPUs, which can lead
 to unrelated processes being able to read/write to each other's virtual memory.
 See the commit for full details.
 
 That is the fix for CVE-2019-12817.
 
 This also adds a kernel selftest for the bug.
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Merge tag 'powerpc-5.2-6' into fixes

This merges the commits that were the fix for CVE-2019-12817, which was
developed under embargo. They have already been merged by Linus

Merge them into fixes now so that this branch contains all the fixes for
this release.
2019-07-01 13:59:40 +10:00
Nicholas Piggin
e13e7cd4c0 powerpc/64s/exception: Fix machine check early corrupting AMR
The early machine check runs in real mode, so locking is unnecessary.
Worse, the windup does not restore AMR, so this can result in a false
KUAP fault after a recoverable machine check hits inside a user copy
operation.

Fix this similarly to HMI by just avoiding the kuap lock in the
early machine check handler (it will be set by the late handler that
runs in virtual mode if that runs). If the virtual mode handler is
reached, it will lock and restore the AMR.

Fixes: 890274c2dc ("powerpc/64s: Implement KUAP for Radix MMU")
Cc: Russell Currey <ruscur@russell.cc>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-25 21:04:27 +10:00
Suraj Jitindar Singh
3c25ab35fb KVM: PPC: Book3S HV: Clear pending decrementer exceptions on nested guest entry
If we enter an L1 guest with a pending decrementer exception then this
is cleared on guest exit if the guest has writtien a positive value
into the decrementer (indicating that it handled the decrementer
exception) since there is no other way to detect that the guest has
handled the pending exception and that it should be dequeued. In the
event that the L1 guest tries to run a nested (L2) guest immediately
after this and the L2 guest decrementer is negative (which is loaded
by L1 before making the H_ENTER_NESTED hcall), then the pending
decrementer exception isn't cleared and the L2 entry is blocked since
L1 has a pending exception, even though L1 may have already handled
the exception and written a positive value for it's decrementer. This
results in a loop of L1 trying to enter the L2 guest and L0 blocking
the entry since L1 has an interrupt pending with the outcome being
that L2 never gets to run and hangs.

Fix this by clearing any pending decrementer exceptions when L1 makes
the H_ENTER_NESTED hcall since it won't do this if it's decrementer
has gone negative, and anyway it's decrementer has been communicated
to L0 in the hdec_expires field and L0 will return control to L1 when
this goes negative by delivering an H_DECREMENTER exception.

Fixes: 95a6432ce9 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-20 23:52:13 +10:00
Suraj Jitindar Singh
869537709e KVM: PPC: Book3S HV: Signed extend decrementer value if not using large decrementer
On POWER9 the decrementer can operate in large decrementer mode where
the decrementer is 56 bits and signed extended to 64 bits. When not
operating in this mode the decrementer behaves as a 32 bit decrementer
which is NOT signed extended (as on POWER8).

Currently when reading a guest decrementer value we don't take into
account whether the large decrementer is enabled or not, and this
means the value will be incorrect when the guest is not using the
large decrementer. Fix this by sign extending the value read when the
guest isn't using the large decrementer.

Fixes: 95a6432ce9 ("KVM: PPC: Book3S HV: Streamlined guest entry/exit path on P9 for radix guests")
Cc: stable@vger.kernel.org # v4.20+
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-20 23:51:22 +10:00
Suraj Jitindar Singh
5008711259 KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entries
When a guest vcpu moves from one physical thread to another it is
necessary for the host to perform a tlb flush on the previous core if
another vcpu from the same guest is going to run there. This is because the
guest may use the local form of the tlb invalidation instruction meaning
stale tlb entries would persist where it previously ran. This is handled
on guest entry in kvmppc_check_need_tlb_flush() which calls
flush_guest_tlb() to perform the tlb flush.

Previously the generic radix__local_flush_tlb_lpid_guest() function was
used, however the functionality was reimplemented in flush_guest_tlb()
to avoid the trace_tlbie() call as the flushing may be done in real
mode. The reimplementation in flush_guest_tlb() was missing an erat
invalidation after flushing the tlb.

This lead to observable memory corruption in the guest due to the
caching of stale translations. Fix this by adding the erat invalidation.

Fixes: 70ea13f6e6 ("KVM: PPC: Book3S HV: Flush TLB on secondary radix threads")
Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-06-20 22:11:25 +10:00