<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/powerpc, branch v6.0.8</title>
<subtitle>Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git</subtitle>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/'/>
<entry>
<title>powerpc/64s/interrupt: Fix clear of PACA_IRQS_HARD_DIS when returning to soft-masked context</title>
<updated>2022-11-03T15:00:25+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2022-10-22T05:22:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=096fcd3381c456b9b241e145cc33065ffe41bac9'/>
<id>096fcd3381c456b9b241e145cc33065ffe41bac9</id>
<content type='text'>
commit 65722736c3baf29e02e964a09e85c9ef71c48e8d upstream.

Commit a4cb3651a1743 ("powerpc/64s/interrupt: Fix lost interrupts when
returning to soft-masked context") fixed the problem of pending irqs
being cleared when clearing the HARD_DIS bit, but then it didn't clear
the bit at all. This change clears HARD_DIS without affecting other bits
in the mask.

When an interrupt hits in a soft-masked section that has MSR[EE]=1, it
can hard disable and set PACA_IRQS_HARD_DIS, which must be cleared when
returning to the EE=1 caller (unless it was set due to a MUST_HARD_MASK
interrupt becoming pending). Failure to clear this leaves the
returned-to context running with MSR[EE]=1 and PACA_IRQS_HARD_DIS, which
confuses irq assertions and could be dangerous for code that might test
the flag.

This was observed in a hash MMU kernel where a kernel hash fault hits in
a local_irqs_disabled region that has EE=1. The hash fault also runs
with EE=1, then as it returns, a decrementer hits in the restart section
and the irq restart code hard-masks which sets the PACA_IRQ_HARD_DIS
flag, which is not clear when the original context is returned to.

Reported-by: Sachin Sant &lt;sachinp@linux.ibm.com&gt;
Fixes: a4cb3651a1743 ("powerpc/64s/interrupt: Fix lost interrupts when returning to soft-masked context")
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Tested-by: Sachin Sant &lt;sachinp@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20221022052207.471328-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 65722736c3baf29e02e964a09e85c9ef71c48e8d upstream.

Commit a4cb3651a1743 ("powerpc/64s/interrupt: Fix lost interrupts when
returning to soft-masked context") fixed the problem of pending irqs
being cleared when clearing the HARD_DIS bit, but then it didn't clear
the bit at all. This change clears HARD_DIS without affecting other bits
in the mask.

When an interrupt hits in a soft-masked section that has MSR[EE]=1, it
can hard disable and set PACA_IRQS_HARD_DIS, which must be cleared when
returning to the EE=1 caller (unless it was set due to a MUST_HARD_MASK
interrupt becoming pending). Failure to clear this leaves the
returned-to context running with MSR[EE]=1 and PACA_IRQS_HARD_DIS, which
confuses irq assertions and could be dangerous for code that might test
the flag.

This was observed in a hash MMU kernel where a kernel hash fault hits in
a local_irqs_disabled region that has EE=1. The hash fault also runs
with EE=1, then as it returns, a decrementer hits in the restart section
and the irq restart code hard-masks which sets the PACA_IRQ_HARD_DIS
flag, which is not clear when the original context is returned to.

Reported-by: Sachin Sant &lt;sachinp@linux.ibm.com&gt;
Fixes: a4cb3651a1743 ("powerpc/64s/interrupt: Fix lost interrupts when returning to soft-masked context")
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Tested-by: Sachin Sant &lt;sachinp@linux.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20221022052207.471328-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64s/interrupt: Fix lost interrupts when returning to soft-masked context</title>
<updated>2022-10-21T10:39:28+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2022-10-13T06:44:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=bb3ff5c52b2793b40b986af8b3c2b74ebd0f8b44'/>
<id>bb3ff5c52b2793b40b986af8b3c2b74ebd0f8b44</id>
<content type='text'>
commit a4cb3651a174366cc85a677da9e3681fbe97fdae upstream.

It's possible for an interrupt returning to an irqs-disabled context to
lose a pending soft-masked irq because it branches to part of the exit
code for irqs-enabled contexts, which is meant to clear only the
PACA_IRQS_HARD_DIS flag from PACAIRQHAPPENED by zeroing the byte. This
just looks like a simple thinko from a recent commit (if there was no
hard mask pending, there would be no reason to clear it anyway).

This also adds comment to the code that actually does need to clear the
flag.

Fixes: e485f6c751e0a ("powerpc/64/interrupt: Fix return to masked context after hard-mask irq becomes pending")
Reported-by: Sachin Sant &lt;sachinp@linux.ibm.com&gt;
Reported-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20221013064418.1311104-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit a4cb3651a174366cc85a677da9e3681fbe97fdae upstream.

It's possible for an interrupt returning to an irqs-disabled context to
lose a pending soft-masked irq because it branches to part of the exit
code for irqs-enabled contexts, which is meant to clear only the
PACA_IRQS_HARD_DIS flag from PACAIRQHAPPENED by zeroing the byte. This
just looks like a simple thinko from a recent commit (if there was no
hard mask pending, there would be no reason to clear it anyway).

This also adds comment to the code that actually does need to clear the
flag.

Fixes: e485f6c751e0a ("powerpc/64/interrupt: Fix return to masked context after hard-mask irq becomes pending")
Reported-by: Sachin Sant &lt;sachinp@linux.ibm.com&gt;
Reported-by: Guenter Roeck &lt;linux@roeck-us.net&gt;
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20221013064418.1311104-1-npiggin@gmail.com
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/pseries/vas: Pass hw_cpu_id to node associativity HCALL</title>
<updated>2022-10-21T10:38:57+00:00</updated>
<author>
<name>Haren Myneni</name>
<email>haren@linux.ibm.com</email>
</author>
<published>2022-09-29T01:57:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=1145320e44005664d10c889e3ff6668b76de67b2'/>
<id>1145320e44005664d10c889e3ff6668b76de67b2</id>
<content type='text'>
[ Upstream commit f3e5d9e53e74d77e711a2c90a91a8b0836a9e0b3 ]

Generally the hypervisor decides to allocate a window on different
VAS instances. But if user space wishes to allocate on the current VAS
instance where the process is executing, the kernel has to pass
associativity domain IDs to allocate VAS window HCALL.

To determine the associativity domain IDs for the current CPU,
smp_processor_id() is passed to node associativity HCALL which may
return H_P2 (-55) error during DLPAR CPU event. This is because Linux
CPU numbers (smp_processor_id()) are not the same as the hypervisor's
view of CPU numbers.

Fix the issue by passing hard_smp_processor_id() with
VPHN_FLAG_VCPU flag (PAPR 14.11.6.1 H_HOME_NODE_ASSOCIATIVITY).

Fixes: b22f2d88e435 ("powerpc/pseries/vas: Integrate API with open/close windows")
Reviewed-by: Nathan Lynch &lt;nathanl@linux.ibm.com&gt;
Signed-off-by: Haren Myneni &lt;haren@linux.ibm.com&gt;
[mpe: Update change log to mention Linux vs HV CPU numbers]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/55380253ea0c11341824cd4c0fc6bbcfc5752689.camel@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit f3e5d9e53e74d77e711a2c90a91a8b0836a9e0b3 ]

Generally the hypervisor decides to allocate a window on different
VAS instances. But if user space wishes to allocate on the current VAS
instance where the process is executing, the kernel has to pass
associativity domain IDs to allocate VAS window HCALL.

To determine the associativity domain IDs for the current CPU,
smp_processor_id() is passed to node associativity HCALL which may
return H_P2 (-55) error during DLPAR CPU event. This is because Linux
CPU numbers (smp_processor_id()) are not the same as the hypervisor's
view of CPU numbers.

Fix the issue by passing hard_smp_processor_id() with
VPHN_FLAG_VCPU flag (PAPR 14.11.6.1 H_HOME_NODE_ASSOCIATIVITY).

Fixes: b22f2d88e435 ("powerpc/pseries/vas: Integrate API with open/close windows")
Reviewed-by: Nathan Lynch &lt;nathanl@linux.ibm.com&gt;
Signed-off-by: Haren Myneni &lt;haren@linux.ibm.com&gt;
[mpe: Update change log to mention Linux vs HV CPU numbers]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/55380253ea0c11341824cd4c0fc6bbcfc5752689.camel@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/kprobes: Fix null pointer reference in arch_prepare_kprobe()</title>
<updated>2022-10-21T10:38:57+00:00</updated>
<author>
<name>Li Huafei</name>
<email>lihuafei1@huawei.com</email>
</author>
<published>2022-09-23T09:32:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=5fd1b369387c53ee6c774ab86e32e362a1e537ac'/>
<id>5fd1b369387c53ee6c774ab86e32e362a1e537ac</id>
<content type='text'>
[ Upstream commit 97f88a3d723162781d6cbfdc7b9617eefab55b19 ]

I found a null pointer reference in arch_prepare_kprobe():

  # echo 'p cmdline_proc_show' &gt; kprobe_events
  # echo 'p cmdline_proc_show+16' &gt;&gt; kprobe_events
  Kernel attempted to read user page (0) - exploit attempt? (uid: 0)
  BUG: Kernel NULL pointer dereference on read at 0x00000000
  Faulting instruction address: 0xc000000000050bfc
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV
  Modules linked in:
  CPU: 0 PID: 122 Comm: sh Not tainted 6.0.0-rc3-00007-gdcf8e5633e2e #10
  NIP:  c000000000050bfc LR: c000000000050bec CTR: 0000000000005bdc
  REGS: c0000000348475b0 TRAP: 0300   Not tainted  (6.0.0-rc3-00007-gdcf8e5633e2e)
  MSR:  9000000000009033 &lt;SF,HV,EE,ME,IR,DR,RI,LE&gt;  CR: 88002444  XER: 20040006
  CFAR: c00000000022d100 DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 0
  ...
  NIP arch_prepare_kprobe+0x10c/0x2d0
  LR  arch_prepare_kprobe+0xfc/0x2d0
  Call Trace:
    0xc0000000012f77a0 (unreliable)
    register_kprobe+0x3c0/0x7a0
    __register_trace_kprobe+0x140/0x1a0
    __trace_kprobe_create+0x794/0x1040
    trace_probe_create+0xc4/0xe0
    create_or_delete_trace_kprobe+0x2c/0x80
    trace_parse_run_command+0xf0/0x210
    probes_write+0x20/0x40
    vfs_write+0xfc/0x450
    ksys_write+0x84/0x140
    system_call_exception+0x17c/0x3a0
    system_call_vectored_common+0xe8/0x278
  --- interrupt: 3000 at 0x7fffa5682de0
  NIP:  00007fffa5682de0 LR: 0000000000000000 CTR: 0000000000000000
  REGS: c000000034847e80 TRAP: 3000   Not tainted  (6.0.0-rc3-00007-gdcf8e5633e2e)
  MSR:  900000000280f033 &lt;SF,HV,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE&gt;  CR: 44002408  XER: 00000000

The address being probed has some special:

  cmdline_proc_show: Probe based on ftrace
  cmdline_proc_show+16: Probe for the next instruction at the ftrace location

The ftrace-based kprobe does not generate kprobe::ainsn::insn, it gets
set to NULL. In arch_prepare_kprobe() it will check for:

  ...
  prev = get_kprobe(p-&gt;addr - 1);
  preempt_enable_no_resched();
  if (prev &amp;&amp; ppc_inst_prefixed(ppc_inst_read(prev-&gt;ainsn.insn))) {
  ...

If prev is based on ftrace, 'ppc_inst_read(prev-&gt;ainsn.insn)' will occur
with a null pointer reference. At this point prev-&gt;addr will not be a
prefixed instruction, so the check can be skipped.

Check if prev is ftrace-based kprobe before reading 'prev-&gt;ainsn.insn'
to fix this problem.

Fixes: b4657f7650ba ("powerpc/kprobes: Don't allow breakpoints on suffixes")
Signed-off-by: Li Huafei &lt;lihuafei1@huawei.com&gt;
[mpe: Trim oops]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220923093253.177298-1-lihuafei1@huawei.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 97f88a3d723162781d6cbfdc7b9617eefab55b19 ]

I found a null pointer reference in arch_prepare_kprobe():

  # echo 'p cmdline_proc_show' &gt; kprobe_events
  # echo 'p cmdline_proc_show+16' &gt;&gt; kprobe_events
  Kernel attempted to read user page (0) - exploit attempt? (uid: 0)
  BUG: Kernel NULL pointer dereference on read at 0x00000000
  Faulting instruction address: 0xc000000000050bfc
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV
  Modules linked in:
  CPU: 0 PID: 122 Comm: sh Not tainted 6.0.0-rc3-00007-gdcf8e5633e2e #10
  NIP:  c000000000050bfc LR: c000000000050bec CTR: 0000000000005bdc
  REGS: c0000000348475b0 TRAP: 0300   Not tainted  (6.0.0-rc3-00007-gdcf8e5633e2e)
  MSR:  9000000000009033 &lt;SF,HV,EE,ME,IR,DR,RI,LE&gt;  CR: 88002444  XER: 20040006
  CFAR: c00000000022d100 DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 0
  ...
  NIP arch_prepare_kprobe+0x10c/0x2d0
  LR  arch_prepare_kprobe+0xfc/0x2d0
  Call Trace:
    0xc0000000012f77a0 (unreliable)
    register_kprobe+0x3c0/0x7a0
    __register_trace_kprobe+0x140/0x1a0
    __trace_kprobe_create+0x794/0x1040
    trace_probe_create+0xc4/0xe0
    create_or_delete_trace_kprobe+0x2c/0x80
    trace_parse_run_command+0xf0/0x210
    probes_write+0x20/0x40
    vfs_write+0xfc/0x450
    ksys_write+0x84/0x140
    system_call_exception+0x17c/0x3a0
    system_call_vectored_common+0xe8/0x278
  --- interrupt: 3000 at 0x7fffa5682de0
  NIP:  00007fffa5682de0 LR: 0000000000000000 CTR: 0000000000000000
  REGS: c000000034847e80 TRAP: 3000   Not tainted  (6.0.0-rc3-00007-gdcf8e5633e2e)
  MSR:  900000000280f033 &lt;SF,HV,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE&gt;  CR: 44002408  XER: 00000000

The address being probed has some special:

  cmdline_proc_show: Probe based on ftrace
  cmdline_proc_show+16: Probe for the next instruction at the ftrace location

The ftrace-based kprobe does not generate kprobe::ainsn::insn, it gets
set to NULL. In arch_prepare_kprobe() it will check for:

  ...
  prev = get_kprobe(p-&gt;addr - 1);
  preempt_enable_no_resched();
  if (prev &amp;&amp; ppc_inst_prefixed(ppc_inst_read(prev-&gt;ainsn.insn))) {
  ...

If prev is based on ftrace, 'ppc_inst_read(prev-&gt;ainsn.insn)' will occur
with a null pointer reference. At this point prev-&gt;addr will not be a
prefixed instruction, so the check can be skipped.

Check if prev is ftrace-based kprobe before reading 'prev-&gt;ainsn.insn'
to fix this problem.

Fixes: b4657f7650ba ("powerpc/kprobes: Don't allow breakpoints on suffixes")
Signed-off-by: Li Huafei &lt;lihuafei1@huawei.com&gt;
[mpe: Trim oops]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220923093253.177298-1-lihuafei1@huawei.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Fix SPE Power ISA properties for e500v1 platforms</title>
<updated>2022-10-21T10:38:57+00:00</updated>
<author>
<name>Pali Rohár</name>
<email>pali@kernel.org</email>
</author>
<published>2022-09-02T21:21:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=cf11c404be430d17d3a29ff48f117cba190eb0b2'/>
<id>cf11c404be430d17d3a29ff48f117cba190eb0b2</id>
<content type='text'>
[ Upstream commit 37b9345ce7f4ab17538ea62def6f6d430f091355 ]

Commit 2eb28006431c ("powerpc/e500v2: Add Power ISA properties to comply
with ePAPR 1.1") introduced new include file e500v2_power_isa.dtsi and
should have used it for all e500v2 platforms. But apparently it was used
also for e500v1 platforms mpc8540, mpc8541, mpc8555 and mpc8560.

e500v1 cores compared to e500v2 do not support double precision floating
point SPE instructions. Hence power-isa-sp.fd should not be set on e500v1
platforms, which is in e500v2_power_isa.dtsi include file.

Fix this issue by introducing a new e500v1_power_isa.dtsi include file and
use it in all e500v1 device tree files.

Fixes: 2eb28006431c ("powerpc/e500v2: Add Power ISA properties to comply with ePAPR 1.1")
Signed-off-by: Pali Rohár &lt;pali@kernel.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220902212103.22534-1-pali@kernel.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 37b9345ce7f4ab17538ea62def6f6d430f091355 ]

Commit 2eb28006431c ("powerpc/e500v2: Add Power ISA properties to comply
with ePAPR 1.1") introduced new include file e500v2_power_isa.dtsi and
should have used it for all e500v2 platforms. But apparently it was used
also for e500v1 platforms mpc8540, mpc8541, mpc8555 and mpc8560.

e500v1 cores compared to e500v2 do not support double precision floating
point SPE instructions. Hence power-isa-sp.fd should not be set on e500v1
platforms, which is in e500v2_power_isa.dtsi include file.

Fix this issue by introducing a new e500v1_power_isa.dtsi include file and
use it in all e500v1 device tree files.

Fixes: 2eb28006431c ("powerpc/e500v2: Add Power ISA properties to comply with ePAPR 1.1")
Signed-off-by: Pali Rohár &lt;pali@kernel.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220902212103.22534-1-pali@kernel.org
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64/interrupt: Fix return to masked context after hard-mask irq becomes pending</title>
<updated>2022-10-21T10:38:57+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2022-09-26T05:43:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=f68c6f756c619f586ab50c9b8025ead62d2352c0'/>
<id>f68c6f756c619f586ab50c9b8025ead62d2352c0</id>
<content type='text'>
[ Upstream commit e485f6c751e0a969327336c635ca602feea117f0 ]

If a synchronous interrupt (e.g., hash fault) is taken inside an
irqs-disabled region which has MSR[EE]=1, then an asynchronous interrupt
that is PACA_IRQ_MUST_HARD_MASK (e.g., PMI) is taken inside the
synchronous interrupt handler, then the synchronous interrupt will
return with MSR[EE]=1 and the asynchronous interrupt fires again.

If the asynchronous interrupt is a PMI and the original context does not
have PMIs disabled (only Linux IRQs), the asynchronous interrupt will
fire despite having the PMI marked soft pending. This can confuse the
perf code and cause warnings.

This patch changes the interrupt return so that irqs-disabled MSR[EE]=1
contexts will be returned to with MSR[EE]=0 if a PACA_IRQ_MUST_HARD_MASK
interrupt has become pending in the meantime.

The longer explanation for what happens:
1. local_irq_disable()
2. Hash fault interrupt fires, do_hash_fault handler runs
3. interrupt_enter_prepare() sets IRQS_ALL_DISABLED
4. interrupt_enter_prepare() sets MSR[EE]=1
5. PMU interrupt fires, masked handler runs
6. Masked handler marks PMI pending
7. Masked handler returns with PACA_IRQ_HARD_DIS set, MSR[EE]=0
8. do_hash_fault interrupt return handler runs
9. interrupt_exit_kernel_prepare() clears PACA_IRQ_HARD_DIS
10. interrupt returns with MSR[EE]=1
11. PMU interrupt fires, perf handler runs

Fixes: 4423eb5ae32e ("powerpc/64/interrupt: make normal synchronous interrupts enable MSR[EE] if possible")
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220926054305.2671436-4-npiggin@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit e485f6c751e0a969327336c635ca602feea117f0 ]

If a synchronous interrupt (e.g., hash fault) is taken inside an
irqs-disabled region which has MSR[EE]=1, then an asynchronous interrupt
that is PACA_IRQ_MUST_HARD_MASK (e.g., PMI) is taken inside the
synchronous interrupt handler, then the synchronous interrupt will
return with MSR[EE]=1 and the asynchronous interrupt fires again.

If the asynchronous interrupt is a PMI and the original context does not
have PMIs disabled (only Linux IRQs), the asynchronous interrupt will
fire despite having the PMI marked soft pending. This can confuse the
perf code and cause warnings.

This patch changes the interrupt return so that irqs-disabled MSR[EE]=1
contexts will be returned to with MSR[EE]=0 if a PACA_IRQ_MUST_HARD_MASK
interrupt has become pending in the meantime.

The longer explanation for what happens:
1. local_irq_disable()
2. Hash fault interrupt fires, do_hash_fault handler runs
3. interrupt_enter_prepare() sets IRQS_ALL_DISABLED
4. interrupt_enter_prepare() sets MSR[EE]=1
5. PMU interrupt fires, masked handler runs
6. Masked handler marks PMI pending
7. Masked handler returns with PACA_IRQ_HARD_DIS set, MSR[EE]=0
8. do_hash_fault interrupt return handler runs
9. interrupt_exit_kernel_prepare() clears PACA_IRQ_HARD_DIS
10. interrupt returns with MSR[EE]=1
11. PMU interrupt fires, perf handler runs

Fixes: 4423eb5ae32e ("powerpc/64/interrupt: make normal synchronous interrupts enable MSR[EE] if possible")
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220926054305.2671436-4-npiggin@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64: mark irqs hard disabled in boot paca</title>
<updated>2022-10-21T10:38:57+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2022-09-26T05:43:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=103fe7ae96b7ce5ebcda478b20b4ae4a87622697'/>
<id>103fe7ae96b7ce5ebcda478b20b4ae4a87622697</id>
<content type='text'>
[ Upstream commit 799f7063c7645f9a751d17f5dfd73b952f962cd2 ]

This prevents interrupts in early boot (e.g., program check) from
enabling MSR[EE], potentially causing endian mismatch or other
crashes when reporting early boot traps.

Fixes: 4423eb5ae32ec ("powerpc/64/interrupt: make normal synchronous interrupts enable MSR[EE] if possible")
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220926054305.2671436-3-npiggin@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 799f7063c7645f9a751d17f5dfd73b952f962cd2 ]

This prevents interrupts in early boot (e.g., program check) from
enabling MSR[EE], potentially causing endian mismatch or other
crashes when reporting early boot traps.

Fixes: 4423eb5ae32ec ("powerpc/64/interrupt: make normal synchronous interrupts enable MSR[EE] if possible")
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220926054305.2671436-3-npiggin@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64/interrupt: Fix false warning in context tracking due to idle state</title>
<updated>2022-10-21T10:38:57+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2022-09-26T05:42:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=387df471e2a3b947f2d2678a0161ba0107732a47'/>
<id>387df471e2a3b947f2d2678a0161ba0107732a47</id>
<content type='text'>
[ 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 &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220926054305.2671436-2-npiggin@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ 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 &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220926054305.2671436-2-npiggin@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64s: Fix GENERIC_CPU build flags for PPC970 / G5</title>
<updated>2022-10-21T10:38:57+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2022-09-21T01:41:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=98d43d681c39ebe5fae11ef68bf1be8a20c1d3fb'/>
<id>98d43d681c39ebe5fae11ef68bf1be8a20c1d3fb</id>
<content type='text'>
[ Upstream commit 58ec7f06b74e0d6e76c4110afce367c8b5f0837d ]

Big-endian GENERIC_CPU supports 970, but builds with -mcpu=power5.
POWER5 is ISA v2.02 whereas 970 is v2.01 plus Altivec. 2.02 added
the popcntb instruction which a compiler might use.

Use -mcpu=power4.

Fixes: 471d7ff8b51b ("powerpc/64s: Remove POWER4 support")
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Reviewed-by: Segher Boessenkool &lt;segher@kernel.crashing.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220921014103.587954-1-npiggin@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 58ec7f06b74e0d6e76c4110afce367c8b5f0837d ]

Big-endian GENERIC_CPU supports 970, but builds with -mcpu=power5.
POWER5 is ISA v2.02 whereas 970 is v2.01 plus Altivec. 2.02 added
the popcntb instruction which a compiler might use.

Use -mcpu=power4.

Fixes: 471d7ff8b51b ("powerpc/64s: Remove POWER4 support")
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Reviewed-by: Segher Boessenkool &lt;segher@kernel.crashing.org&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220921014103.587954-1-npiggin@gmail.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Fix fallocate and fadvise64_64 compat parameter combination</title>
<updated>2022-10-21T10:38:56+00:00</updated>
<author>
<name>Rohan McLure</name>
<email>rmclure@linux.ibm.com</email>
</author>
<published>2022-09-21T06:55:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.exis.tech/linux.git/commit/?id=56ab37073a6a9177c6290c5dfe825448a84474dd'/>
<id>56ab37073a6a9177c6290c5dfe825448a84474dd</id>
<content type='text'>
[ 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 &lt;arnd@arndb.de&gt;
Signed-off-by: Rohan McLure &lt;rmclure@linux.ibm.com&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Reviewed-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220921065605.1051927-9-rmclure@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ 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 &lt;arnd@arndb.de&gt;
Signed-off-by: Rohan McLure &lt;rmclure@linux.ibm.com&gt;
Reviewed-by: Arnd Bergmann &lt;arnd@arndb.de&gt;
Reviewed-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Link: https://lore.kernel.org/r/20220921065605.1051927-9-rmclure@linux.ibm.com
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
