<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/powerpc/kernel/traps.c, branch v4.13</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>powerpc/64s: Blacklist functions invoked on a trap</title>
<updated>2017-07-03T13:12:01+00:00</updated>
<author>
<name>Naveen N. Rao</name>
<email>naveen.n.rao@linux.vnet.ibm.com</email>
</author>
<published>2017-06-29T17:49:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=15770a13bebc7fae2fbc06bc4cc708a3f724c586'/>
<id>15770a13bebc7fae2fbc06bc4cc708a3f724c586</id>
<content type='text'>
Blacklist all functions involved while handling a trap. We:
- convert some of the symbols into private symbols, and
- blacklist most functions involved while handling a trap.

Reviewed-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Signed-off-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Blacklist all functions involved while handling a trap. We:
- convert some of the symbols into private symbols, and
- blacklist most functions involved while handling a trap.

Reviewed-by: Masami Hiramatsu &lt;mhiramat@kernel.org&gt;
Signed-off-by: Naveen N. Rao &lt;naveen.n.rao@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/book3s/mce: Move add_taint() later in virtual mode</title>
<updated>2017-05-03T04:45:39+00:00</updated>
<author>
<name>Mahesh Salgaonkar</name>
<email>mahesh@linux.vnet.ibm.com</email>
</author>
<published>2017-04-18T16:38:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=d93b0ac01a9ce276ec39644be47001873d3d183c'/>
<id>d93b0ac01a9ce276ec39644be47001873d3d183c</id>
<content type='text'>
machine_check_early() gets called in real mode. The very first time when
add_taint() is called, it prints a warning which ends up calling opal
call (that uses OPAL_CALL wrapper) for writing it to console. If we get a
very first machine check while we are in opal we are doomed. OPAL_CALL
overwrites the PACASAVEDMSR in r13 and in this case when we are done with
MCE handling the original opal call will use this new MSR on it's way
back to opal_return. This usually leads to unexpected behaviour or the
kernel to panic. Instead move the add_taint() call later in the virtual
mode where it is safe to call.

This is broken with current FW level. We got lucky so far for not getting
very first MCE hit while in OPAL. But easily reproducible on Mambo.

Fixes: 27ea2c420cad ("powerpc: Set the correct kernel taint on machine check errors.")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Mahesh Salgaonkar &lt;mahesh@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
machine_check_early() gets called in real mode. The very first time when
add_taint() is called, it prints a warning which ends up calling opal
call (that uses OPAL_CALL wrapper) for writing it to console. If we get a
very first machine check while we are in opal we are doomed. OPAL_CALL
overwrites the PACASAVEDMSR in r13 and in this case when we are done with
MCE handling the original opal call will use this new MSR on it's way
back to opal_return. This usually leads to unexpected behaviour or the
kernel to panic. Instead move the add_taint() call later in the virtual
mode where it is safe to call.

This is broken with current FW level. We got lucky so far for not getting
very first MCE hit while in OPAL. But easily reproducible on Mambo.

Fixes: 27ea2c420cad ("powerpc: Set the correct kernel taint on machine check errors.")
Cc: stable@vger.kernel.org # v4.2+
Signed-off-by: Mahesh Salgaonkar &lt;mahesh@linux.vnet.ibm.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Mark system reset as an NMI with nmi_enter/exit()</title>
<updated>2017-04-28T11:02:25+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2016-12-19T18:30:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2b4f3ac5642672595ef6f71d1572b32475e94863'/>
<id>2b4f3ac5642672595ef6f71d1572b32475e94863</id>
<content type='text'>
System reset is a non-maskable interrupt from Linux's point of view
(occurs under local_irq_disable()), so it should use nmi_enter/exit.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
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<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
System reset is a non-maskable interrupt from Linux's point of view
(occurs under local_irq_disable()), so it should use nmi_enter/exit.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64s: Disallow system reset vs system reset reentrancy</title>
<updated>2017-04-28T11:02:25+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2016-12-19T18:30:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c4f3b52ce7b16824befb16ab3d045c891b08b7db'/>
<id>c4f3b52ce7b16824befb16ab3d045c891b08b7db</id>
<content type='text'>
In preparation for using a dedicated stack for system reset interrupts,
prevent a nested system reset from recovering, in order to simplify
code that is called in crash/debug path. This allows a system reset
interrupt to just use the base stack pointer.

Keep an in_nmi nesting counter similarly to the in_mce counter. Consider
the interrrupt non-recoverable if it is taken inside another system
reset.

Interrupt nesting could be allowed similarly to MCE, but system reset
is a special case that's not for normal operation, so simplicity wins
until there is requirement for nested system reset interrupts.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In preparation for using a dedicated stack for system reset interrupts,
prevent a nested system reset from recovering, in order to simplify
code that is called in crash/debug path. This allows a system reset
interrupt to just use the base stack pointer.

Keep an in_nmi nesting counter similarly to the in_mce counter. Consider
the interrrupt non-recoverable if it is taken inside another system
reset.

Interrupt nesting could be allowed similarly to MCE, but system reset
is a special case that's not for normal operation, so simplicity wins
until there is requirement for nested system reset interrupts.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64s: Add SCV FSCR bit for ISA v3.0</title>
<updated>2017-04-13T13:34:32+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2017-04-07T01:27:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9b7ff0c6586bc0541ebcd1ff6773b11a49f1a058'/>
<id>9b7ff0c6586bc0541ebcd1ff6773b11a49f1a058</id>
<content type='text'>
Add the bit definition and use it in facility_unavailable_exception() so we can
intelligently report the cause if we take a fault for SCV. This doesn't actually
enable SCV.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
[mpe: Drop whitespace changes to the existing entries, flush out change log]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Add the bit definition and use it in facility_unavailable_exception() so we can
intelligently report the cause if we take a fault for SCV. This doesn't actually
enable SCV.

Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
[mpe: Drop whitespace changes to the existing entries, flush out change log]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc/64s: Add msgp facility unavailable log string</title>
<updated>2017-04-13T13:34:32+00:00</updated>
<author>
<name>Nicholas Piggin</name>
<email>npiggin@gmail.com</email>
</author>
<published>2017-04-07T01:27:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=794464f4dea0b13dacad267c06a01fc9c24f713a'/>
<id>794464f4dea0b13dacad267c06a01fc9c24f713a</id>
<content type='text'>
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Signed-off-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc: Create asm/debugfs.h and move powerpc_debugfs_root there</title>
<updated>2017-04-10T21:46:03+00:00</updated>
<author>
<name>Michael Ellerman</name>
<email>mpe@ellerman.id.au</email>
</author>
<published>2017-02-10T01:04:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7644d5819cf8956d799a0a0e5dc75f5a29889bd5'/>
<id>7644d5819cf8956d799a0a0e5dc75f5a29889bd5</id>
<content type='text'>
powerpc_debugfs_root is the dentry representing the root of the
"powerpc" directory tree in debugfs.

Currently it sits in asm/debug.h, a long with some other things that
have "debug" in the name, but are otherwise unrelated.

Pull it out into a separate header, which also includes linux/debugfs.h,
and convert all the users to include debugfs.h instead of debug.h.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
powerpc_debugfs_root is the dentry representing the root of the
"powerpc" directory tree in debugfs.

Currently it sits in asm/debug.h, a long with some other things that
have "debug" in the name, but are otherwise unrelated.

Pull it out into a separate header, which also includes linux/debugfs.h,
and convert all the users to include debugfs.h instead of debug.h.

Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sched/headers: Prepare for new header dependencies before moving code to &lt;linux/sched/debug.h&gt;</title>
<updated>2017-03-02T07:42:34+00:00</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-02-08T17:51:35+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b17b01533b719e9949e437abf66436a875739b40'/>
<id>b17b01533b719e9949e437abf66436a875739b40</id>
<content type='text'>
We are going to split &lt;linux/sched/debug.h&gt; out of &lt;linux/sched.h&gt;, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder &lt;linux/sched/debug.h&gt; file that just
maps to &lt;linux/sched.h&gt; to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We are going to split &lt;linux/sched/debug.h&gt; out of &lt;linux/sched.h&gt;, which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder &lt;linux/sched/debug.h&gt; file that just
maps to &lt;linux/sched.h&gt; to make this patch obviously correct and
bisectable.

Include the new header in the files that are going to need it.

Acked-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Mike Galbraith &lt;efault@gmx.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Replace &lt;asm/uaccess.h&gt; with &lt;linux/uaccess.h&gt; globally</title>
<updated>2016-12-24T19:46:01+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-12-24T19:46:01+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=7c0f6ba682b9c7632072ffbedf8d328c8f3c42ba'/>
<id>7c0f6ba682b9c7632072ffbedf8d328c8f3c42ba</id>
<content type='text'>
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*&lt;asm/uaccess.h&gt;'
  sed -i -e "s!$PATT!#include &lt;linux/uaccess.h&gt;!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This was entirely automated, using the script by Al:

  PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*&lt;asm/uaccess.h&gt;'
  sed -i -e "s!$PATT!#include &lt;linux/uaccess.h&gt;!" \
        $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h)

to do the replacement at the end of the merge window.

Requested-by: Al Viro &lt;viro@zeniv.linux.org.uk&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>powerpc Don't print misleading facility name in facility unavailable exception</title>
<updated>2016-12-02T02:00:53+00:00</updated>
<author>
<name>Balbir Singh</name>
<email>bsingharora@gmail.com</email>
</author>
<published>2016-11-30T06:45:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=93c2ec0f7019a155769d1ecfc08a7de83b47e03d'/>
<id>93c2ec0f7019a155769d1ecfc08a7de83b47e03d</id>
<content type='text'>
The current facility_strings[] are correct when the trap address is
0xf80 (hypervisor facility unavailable). When the trap address is
0xf60 (facility unavailable) IC (Interruption Cause) a.k.a status in the
code is undefined for values 0 and 1.

Add a check to prevent printing the (misleading) facility name for IC 0
and 1 when we came in via 0xf60. In all cases, print the actual IC
value, to avoid any confusion.

This hasn't been seen on real hardware, on only qemu which was
misreporting an exception.

Signed-off-by: Balbir Singh &lt;bsingharora@gmail.com&gt;
[mpe: Fix indentation, combine printks(), massage change log]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The current facility_strings[] are correct when the trap address is
0xf80 (hypervisor facility unavailable). When the trap address is
0xf60 (facility unavailable) IC (Interruption Cause) a.k.a status in the
code is undefined for values 0 and 1.

Add a check to prevent printing the (misleading) facility name for IC 0
and 1 when we came in via 0xf60. In all cases, print the actual IC
value, to avoid any confusion.

This hasn't been seen on real hardware, on only qemu which was
misreporting an exception.

Signed-off-by: Balbir Singh &lt;bsingharora@gmail.com&gt;
[mpe: Fix indentation, combine printks(), massage change log]
Signed-off-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
</pre>
</div>
</content>
</entry>
</feed>
