linux-stable.git/arch/powerpc/include, branch v6.0.7

powerpc/64/interrupt: Fix false warning in context tracking due to idle state

2022-10-21T10:38:57+00:00

[ Upstream commit 56adbb7a8b6cc7fc9b940829c38494e53c9e57d1 ]

Commit 171476775d32 ("context_tracking: Convert state to atomic_t")
added a CONTEXT_IDLE state which can be encountered by interrupts from
kernel mode in the idle thread, causing a false positive warning.

Fixes: 171476775d32 ("context_tracking: Convert state to atomic_t")
Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220926054305.2671436-2-npiggin@gmail.com
Signed-off-by: Sasha Levin

powerpc: Fix fallocate and fadvise64_64 compat parameter combination

2022-10-21T10:38:56+00:00

[ Upstream commit 016ff72bd2090903715c0f9422a44afbb966f4ee ]

As reported[1] by Arnd, the arch-specific fadvise64_64 and fallocate
compatibility handlers assume parameters are passed with 32-bit
big-endian ABI. This affects the assignment of odd-even parameter pairs
to the high or low words of a 64-bit syscall parameter.

Fix fadvise64_64 fallocate compat handlers to correctly swap upper/lower
32 bits conditioned on endianness.

A future patch will replace the arch-specific compat fallocate with an
asm-generic implementation. This patch is intended for ease of
back-port.

[1]: https://lore.kernel.org/all/be29926f-226e-48dc-871a-e29a54e80583@www.fastmail.com/

Fixes: 57f48b4b74e7 ("powerpc/compat_sys: swap hi/lo parts of 64-bit syscall args in LE mode")
Reported-by: Arnd Bergmann 
Signed-off-by: Rohan McLure 
Reviewed-by: Arnd Bergmann 
Reviewed-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220921065605.1051927-9-rmclure@linux.ibm.com
Signed-off-by: Sasha Levin

Revert "powerpc/rtas: Implement reentrant rtas call"

2022-10-15T06:02:56+00:00

commit f88aabad33ea22be2ce1c60d8901942e4e2a9edb upstream.

At the time this was submitted by Leonardo, I confirmed -- or thought
I had confirmed -- with PowerVM partition firmware development that
the following RTAS functions:

- ibm,get-xive
- ibm,int-off
- ibm,int-on
- ibm,set-xive

were safe to call on multiple CPUs simultaneously, not only with
respect to themselves as indicated by PAPR, but with arbitrary other
RTAS calls:

https://lore.kernel.org/linuxppc-dev/875zcy2v8o.fsf@linux.ibm.com/

Recent discussion with firmware development makes it clear that this
is not true, and that the code in commit b664db8e3f97 ("powerpc/rtas:
Implement reentrant rtas call") is unsafe, likely explaining several
strange bugs we've seen in internal testing involving DLPAR and
LPM. These scenarios use ibm,configure-connector, whose internal state
can be corrupted by the concurrent use of the "reentrant" functions,
leading to symptoms like endless busy statuses from RTAS.

Fixes: b664db8e3f97 ("powerpc/rtas: Implement reentrant rtas call")
Cc: stable@vger.kernel.org # v5.8+
Signed-off-by: Nathan Lynch 
Reviewed-by: Laurent Dufour 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220907220111.223267-1-nathanl@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman

Revert "powerpc/irq: Don't open code irq_soft_mask helpers"

2022-09-02T08:54:53+00:00

This reverts commit ef5b570d3700fbb8628a58da0487486ceeb713cd.

Zhouyi reported that commit is causing crashes when running rcutorture
with KASAN enabled:

  BUG: using smp_processor_id() in preemptible [00000000] code: rcu_torture_rea/100
  caller is rcu_preempt_deferred_qs_irqrestore+0x74/0xed0
  CPU: 4 PID: 100 Comm: rcu_torture_rea Tainted: G        W          5.19.0-rc5-next-20220708-dirty #253
  Call Trace:
    dump_stack_lvl+0xbc/0x108 (unreliable)
    check_preemption_disabled+0x154/0x160
    rcu_preempt_deferred_qs_irqrestore+0x74/0xed0
    __rcu_read_unlock+0x290/0x3b0
    rcu_torture_read_unlock+0x30/0xb0
    rcutorture_one_extend+0x198/0x810
    rcu_torture_one_read+0x58c/0xc90
    rcu_torture_reader+0x12c/0x360
    kthread+0x1e8/0x220
    ret_from_kernel_thread+0x5c/0x64

KASAN will generate instrumentation instructions around the
WRITE_ONCE(local_paca->irq_soft_mask, mask):

   0xc000000000295cb0 <+0>:	addis   r2,r12,774
   0xc000000000295cb4 <+4>:	addi    r2,r2,16464
   0xc000000000295cb8 <+8>:	mflr    r0
   0xc000000000295cbc <+12>:	bl      0xc00000000008bb4c 
   0xc000000000295cc0 <+16>:	mflr    r0
   0xc000000000295cc4 <+20>:	std     r31,-8(r1)
   0xc000000000295cc8 <+24>:	addi    r3,r13,2354
   0xc000000000295ccc <+28>:	mr      r31,r13
   0xc000000000295cd0 <+32>:	std     r0,16(r1)
   0xc000000000295cd4 <+36>:	stdu    r1,-48(r1)
   0xc000000000295cd8 <+40>:	bl      0xc000000000609b98 <__asan_store1+8>
   0xc000000000295cdc <+44>:	nop
   0xc000000000295ce0 <+48>:	li      r9,1
   0xc000000000295ce4 <+52>:	stb     r9,2354(r31)
   0xc000000000295ce8 <+56>:	addi    r1,r1,48
   0xc000000000295cec <+60>:	ld      r0,16(r1)
   0xc000000000295cf0 <+64>:	ld      r31,-8(r1)
   0xc000000000295cf4 <+68>:	mtlr    r0

If there is a context switch before "stb     r9,2354(r31)", r31 may
not equal to r13, in such case, irq soft mask will not work.

The usual solution of marking the code ineligible for instrumentation
forces the code out-of-line, which we would prefer to avoid. Christophe
proposed a partial revert, but Nick raised some concerns with that. So
for now do a full revert.

Reported-by: Zhouyi Zhou 
[mpe: Construct change log based on Zhouyi's original report]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220831131052.42250-1-mpe@ellerman.id.au

powerpc: Fix hard_irq_disable() with sanitizer

2022-08-31T13:05:27+00:00

As reported by Zhouyi Zhou, WRITE_ONCE() is not atomic
as expected when KASAN or KCSAN are compiled in.

Fix it by re-implementing it using inline assembly.

Fixes: 077fc62b2b66 ("powerpc/irq: remove inline assembly in hard_irq_disable macro")
Reported-by: Zhouyi Zhou 
Signed-off-by: Christophe Leroy 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/a8298991b3df049a54ee8e558838e34265812014.1661272586.git.christophe.leroy@csgroup.eu

Revert "powerpc: Remove unused FW_FEATURE_NATIVE references"

2022-08-25T22:41:54+00:00

This reverts commit 79b74a68486765a4fe685ac4069bc71366c538f5.

It broke booting on IBM Cell machines when the kernel is also built with
CONFIG_PPC_PS3=y.

That's because FW_FEATURE_NATIVE_ALWAYS = 0 does have an important
effect, which is to clear the PS3 ALWAYS features from
FW_FEATURE_ALWAYS.

Note that CONFIG_PPC_NATIVE has since been renamed
CONFIG_PPC_HASH_MMU_NATIVE.

Fixes: 79b74a684867 ("powerpc: Remove unused FW_FEATURE_NATIVE references")
Cc: stable@vger.kernel.org # v5.17+
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/20220823115952.1203106-1-mpe@ellerman.id.au

KVM: Rename mmu_notifier_* to mmu_invalidate_*

2022-08-19T08:05:41+00:00

The motivation of this renaming is to make these variables and related
helper functions less mmu_notifier bound and can also be used for non
mmu_notifier based page invalidation. mmu_invalidate_* was chosen to
better describe the purpose of 'invalidating' a page that those
variables are used for.

  - mmu_notifier_seq/range_start/range_end are renamed to
    mmu_invalidate_seq/range_start/range_end.

  - mmu_notifier_retry{_hva} helper functions are renamed to
    mmu_invalidate_retry{_hva}.

  - mmu_notifier_count is renamed to mmu_invalidate_in_progress to
    avoid confusion with mn_active_invalidate_count.

  - While here, also update kvm_inc/dec_notifier_count() to
    kvm_mmu_invalidate_begin/end() to match the change for
    mmu_notifier_count.

No functional change intended.

Signed-off-by: Chao Peng 
Message-Id: <20220816125322.1110439-3-chao.p.peng@linux.intel.com>
Signed-off-by: Paolo Bonzini

Merge tag 'powerpc-6.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2022-08-14T15:48:13+00:00

Pull powerpc fixes from Michael Ellerman:

 - Ensure we never emit lwarx with EH=1 on 32-bit, because some 32-bit
   CPUs trap on it rather than ignoring it as they should.

 - Fix ftrace when building with clang, which was broken by some
   refactoring.

 - A couple of other minor fixes.

Thanks to Christophe Leroy, Naveen N.  Rao, Nick Desaulniers, Ondrej
Mosnacek, Pali Rohár, Russell Currey, and Segher Boessenkool.

* tag 'powerpc-6.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/kexec: Fix build failure from uninitialised variable
  powerpc/ppc-opcode: Fix PPC_RAW_TW()
  powerpc64/ftrace: Fix ftrace for clang builds
  powerpc: Make eh value more explicit when using lwarx
  powerpc: Don't hide eh field of lwarx behind a macro
  powerpc: Fix eh field when calling lwarx on PPC32

powerpc/ppc-opcode: Fix PPC_RAW_TW()

2022-08-10T05:39:37+00:00

PPC_RAW_TW() is erroneously defined with base code 0x7f000008
instead of 0x7c000008.

That's invisible because its only user is PPC_RAW_TRAP() which is
0x7fe00008, but fix it anyway to avoid any risk of future bug.

Fixes: d00d762daf12 ("powerpc/ppc-opcode: Define and use PPC_RAW_TRAP() and PPC_RAW_TW()")
Reported-by: Naveen N. Rao 
Signed-off-by: Christophe Leroy 
Reviewed-by: Naveen N. Rao 
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/eca9251f1e1f82c4c46ec6380ddb28356ab3fdfe.1659527244.git.christophe.leroy@csgroup.eu

powerpc: Make eh value more explicit when using lwarx

2022-08-10T05:32:20+00:00

Just like the first patch of this series, define a local 'eh' in order
to make the code clearer.

And IS_ENABLED() returns either 1 or 0 so no need to do
IS_ENABLED(CONFIG_PPC64) ? 1 : 0.

Signed-off-by: Christophe Leroy 
[mpe: Use symbolic names, use 'n' constraint per Segher]
Signed-off-by: Michael Ellerman 
Link: https://lore.kernel.org/r/629befaa2d05e2922346e58a383886510d6af55a.1659430931.git.christophe.leroy@csgroup.eu