<feed xmlns='http://www.w3.org/2005/Atom'>
<title>wireguard-linux/arch/arm64/kernel/kgdb.c, branch jd/unified-crypt-queue</title>
<subtitle>WireGuard for the Linux kernel</subtitle>
<id>https://git.zx2c4.com/wireguard-linux/atom/arch/arm64/kernel/kgdb.c?h=jd%2Funified-crypt-queue</id>
<link rel='self' href='https://git.zx2c4.com/wireguard-linux/atom/arch/arm64/kernel/kgdb.c?h=jd%2Funified-crypt-queue'/>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/'/>
<updated>2019-06-19T15:09:07Z</updated>
<entry>
<title>treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234</title>
<updated>2019-06-19T15:09:07Z</updated>
<author>
<name>Thomas Gleixner</name>
<email>tglx@linutronix.de</email>
</author>
<published>2019-06-03T05:44:50Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=caab277b1de0a22b675c4c95fc7b285ec2eb5bf5'/>
<id>urn:sha1:caab277b1de0a22b675c4c95fc7b285ec2eb5bf5</id>
<content type='text'>
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation this program is
  distributed in the hope that it will be useful but without any
  warranty without even the implied warranty of merchantability or
  fitness for a particular purpose see the gnu general public license
  for more details you should have received a copy of the gnu general
  public license along with this program if not see http www gnu org
  licenses

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 503 file(s).

Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Alexios Zavras &lt;alexios.zavras@intel.com&gt;
Reviewed-by: Allison Randal &lt;allison@lohutok.net&gt;
Reviewed-by: Enrico Weigelt &lt;info@metux.net&gt;
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
</entry>
<entry>
<title>arm64: debug: Remove redundant user_mode(regs) checks from debug handlers</title>
<updated>2019-04-09T10:21:13Z</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2019-02-26T15:37:09Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=fb610f2a2006322bebeb30408fefce6a01df09ea'/>
<id>urn:sha1:fb610f2a2006322bebeb30408fefce6a01df09ea</id>
<content type='text'>
Now that the debug hook dispatching code takes the triggering exception
level into account, there's no need for the hooks themselves to poke
around with user_mode(regs).

Reviewed-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
</content>
</entry>
<entry>
<title>arm64: debug: Separate debug hooks based on target exception level</title>
<updated>2019-04-09T10:21:13Z</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2019-02-26T12:52:47Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=26a04d84bc5311d7785b229b353f327e866ab61a'/>
<id>urn:sha1:26a04d84bc5311d7785b229b353f327e866ab61a</id>
<content type='text'>
Mixing kernel and user debug hooks together is highly error-prone as it
relies on all of the hooks to figure out whether the exception came from
kernel or user, and then to act accordingly.

Make our debug hook code a little more robust by maintaining separate
hook lists for user and kernel, with separate registration functions
to force callers to be explicit about the exception levels that they
care about.

Reviewed-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
</content>
</entry>
<entry>
<title>arm64: debug: Ensure debug handlers check triggering exception level</title>
<updated>2019-03-01T16:23:38Z</updated>
<author>
<name>Will Deacon</name>
<email>will.deacon@arm.com</email>
</author>
<published>2019-03-01T13:28:01Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=6bd288569b50bc89fa5513031086746968f585cb'/>
<id>urn:sha1:6bd288569b50bc89fa5513031086746968f585cb</id>
<content type='text'>
Debug exception handlers may be called for exceptions generated both by
user and kernel code. In many cases, this is checked explicitly, but
in other cases things either happen to work by happy accident or they
go slightly wrong. For example, executing 'brk #4' from userspace will
enter the kprobes code and be ignored, but the instruction will be
retried forever in userspace instead of delivering a SIGTRAP.

Fix this issue in the most stable-friendly fashion by simply adding
explicit checks of the triggering exception level to all of our debug
exception handlers.

Cc: &lt;stable@vger.kernel.org&gt;
Reviewed-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
</entry>
<entry>
<title>kgdb/treewide: constify struct kgdb_arch arch_kgdb_ops</title>
<updated>2018-12-30T08:33:06Z</updated>
<author>
<name>Christophe Leroy</name>
<email>christophe.leroy@c-s.fr</email>
</author>
<published>2018-12-06T20:07:40Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=cc0282975b3f887005c380adcf0af95915f0c1bb'/>
<id>urn:sha1:cc0282975b3f887005c380adcf0af95915f0c1bb</id>
<content type='text'>
checkpatch.pl reports the following:

  WARNING: struct kgdb_arch should normally be const
  #28: FILE: arch/mips/kernel/kgdb.c:397:
  +struct kgdb_arch arch_kgdb_ops = {

This report makes sense, as all other ops struct, this
one should also be const. This patch does the change.

Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: Michal Simek &lt;monstr@monstr.eu&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: Ley Foon Tan &lt;lftan@altera.com&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: x86@kernel.org
Acked-by: Daniel Thompson &lt;daniel.thompson@linaro.org&gt;
Acked-by: Paul Burton &lt;paul.burton@mips.com&gt;
Signed-off-by: Christophe Leroy &lt;christophe.leroy@c-s.fr&gt;
Acked-by: Borislav Petkov &lt;bp@suse.de&gt;
Acked-by: Michael Ellerman &lt;mpe@ellerman.id.au&gt; (powerpc)
Signed-off-by: Daniel Thompson &lt;daniel.thompson@linaro.org&gt;
</content>
</entry>
<entry>
<title>kgdb: Fix kgdb_roundup_cpus() for arches who used smp_call_function()</title>
<updated>2018-12-30T08:28:02Z</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2018-12-05T03:38:26Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=3cd99ac3559855f69afbc1d5080e17eaa12394ff'/>
<id>urn:sha1:3cd99ac3559855f69afbc1d5080e17eaa12394ff</id>
<content type='text'>
When I had lockdep turned on and dropped into kgdb I got a nice splat
on my system.  Specifically it hit:
  DEBUG_LOCKS_WARN_ON(current-&gt;hardirq_context)

Specifically it looked like this:
  sysrq: SysRq : DEBUG
  ------------[ cut here ]------------
  DEBUG_LOCKS_WARN_ON(current-&gt;hardirq_context)
  WARNING: CPU: 0 PID: 0 at .../kernel/locking/lockdep.c:2875 lockdep_hardirqs_on+0xf0/0x160
  CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.19.0 #27
  pstate: 604003c9 (nZCv DAIF +PAN -UAO)
  pc : lockdep_hardirqs_on+0xf0/0x160
  ...
  Call trace:
   lockdep_hardirqs_on+0xf0/0x160
   trace_hardirqs_on+0x188/0x1ac
   kgdb_roundup_cpus+0x14/0x3c
   kgdb_cpu_enter+0x53c/0x5cc
   kgdb_handle_exception+0x180/0x1d4
   kgdb_compiled_brk_fn+0x30/0x3c
   brk_handler+0x134/0x178
   do_debug_exception+0xfc/0x178
   el1_dbg+0x18/0x78
   kgdb_breakpoint+0x34/0x58
   sysrq_handle_dbg+0x54/0x5c
   __handle_sysrq+0x114/0x21c
   handle_sysrq+0x30/0x3c
   qcom_geni_serial_isr+0x2dc/0x30c
  ...
  ...
  irq event stamp: ...45
  hardirqs last  enabled at (...44): [...] __do_softirq+0xd8/0x4e4
  hardirqs last disabled at (...45): [...] el1_irq+0x74/0x130
  softirqs last  enabled at (...42): [...] _local_bh_enable+0x2c/0x34
  softirqs last disabled at (...43): [...] irq_exit+0xa8/0x100
  ---[ end trace adf21f830c46e638 ]---

Looking closely at it, it seems like a really bad idea to be calling
local_irq_enable() in kgdb_roundup_cpus().  If nothing else that seems
like it could violate spinlock semantics and cause a deadlock.

Instead, let's use a private csd alongside
smp_call_function_single_async() to round up the other CPUs.  Using
smp_call_function_single_async() doesn't require interrupts to be
enabled so we can remove the offending bit of code.

In order to avoid duplicating this across all the architectures that
use the default kgdb_roundup_cpus(), we'll add a "weak" implementation
to debug_core.c.

Looking at all the people who previously had copies of this code,
there were a few variants.  I've attempted to keep the variants
working like they used to.  Specifically:
* For arch/arc we passed NULL to kgdb_nmicallback() instead of
  get_irq_regs().
* For arch/mips there was a bit of extra code around
  kgdb_nmicallback()

NOTE: In this patch we will still get into trouble if we try to round
up a CPU that failed to round up before.  We'll try to round it up
again and potentially hang when we try to grab the csd lock.  That's
not new behavior but we'll still try to do better in a future patch.

Suggested-by: Daniel Thompson &lt;daniel.thompson@linaro.org&gt;
Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Acked-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Daniel Thompson &lt;daniel.thompson@linaro.org&gt;
</content>
</entry>
<entry>
<title>kgdb: Remove irq flags from roundup</title>
<updated>2018-12-30T08:24:21Z</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2018-12-05T03:38:25Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=9ef7fa507d6b53a96de4da3298c5f01bde603c0a'/>
<id>urn:sha1:9ef7fa507d6b53a96de4da3298c5f01bde603c0a</id>
<content type='text'>
The function kgdb_roundup_cpus() was passed a parameter that was
documented as:

&gt; the flags that will be used when restoring the interrupts. There is
&gt; local_irq_save() call before kgdb_roundup_cpus().

Nobody used those flags.  Anyone who wanted to temporarily turn on
interrupts just did local_irq_enable() and local_irq_disable() without
looking at them.  So we can definitely remove the flags.

Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Cc: Vineet Gupta &lt;vgupta@synopsys.com&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Cc: Richard Kuo &lt;rkuo@codeaurora.org&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: Benjamin Herrenschmidt &lt;benh@kernel.crashing.org&gt;
Cc: Paul Mackerras &lt;paulus@samba.org&gt;
Cc: Michael Ellerman &lt;mpe@ellerman.id.au&gt;
Cc: Yoshinori Sato &lt;ysato@users.sourceforge.jp&gt;
Cc: Rich Felker &lt;dalias@libc.org&gt;
Cc: "David S. Miller" &lt;davem@davemloft.net&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: "H. Peter Anvin" &lt;hpa@zytor.com&gt;
Acked-by: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Daniel Thompson &lt;daniel.thompson@linaro.org&gt;
</content>
</entry>
<entry>
<title>arm64/debug: Fix registers on sleeping tasks</title>
<updated>2018-03-06T18:52:34Z</updated>
<author>
<name>Douglas Anderson</name>
<email>dianders@chromium.org</email>
</author>
<published>2018-03-05T23:43:09Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=24153c03d4f5dc4ac0ccd446a9636c269c1d4a02'/>
<id>urn:sha1:24153c03d4f5dc4ac0ccd446a9636c269c1d4a02</id>
<content type='text'>
This is the equivalent of commit 001bf455d206 ("ARM: 8428/1: kgdb: Fix
registers on sleeping tasks") but for arm64.  Nuff said.

...well, perhaps I could also add that task_pt_regs are userspace
registers and that's not what kgdb is supposed to be reporting.  We're
supposed to be reporting kernel registers.

Signed-off-by: Douglas Anderson &lt;dianders@chromium.org&gt;
Signed-off-by: Will Deacon &lt;will.deacon@arm.com&gt;
</content>
</entry>
<entry>
<title>sched/headers: Prepare for new header dependencies before moving code to &lt;linux/sched/task_stack.h&gt;</title>
<updated>2017-03-02T07:42:36Z</updated>
<author>
<name>Ingo Molnar</name>
<email>mingo@kernel.org</email>
</author>
<published>2017-02-08T17:51:37Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=68db0cf10678630d286f4bbbbdfa102951a35faa'/>
<id>urn:sha1:68db0cf10678630d286f4bbbbdfa102951a35faa</id>
<content type='text'>
We are going to split &lt;linux/sched/task_stack.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/task_stack.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>
</entry>
<entry>
<title>arm64: kgdb_step_brk_fn: ignore other's exception</title>
<updated>2016-11-07T18:15:20Z</updated>
<author>
<name>Pratyush Anand</name>
<email>panand@redhat.com</email>
</author>
<published>2016-11-02T09:10:42Z</published>
<link rel='alternate' type='text/html' href='https://git.zx2c4.com/wireguard-linux/commit/?id=b66c9870e9746038a532f87632bee8c0dcbeee3a'/>
<id>urn:sha1:b66c9870e9746038a532f87632bee8c0dcbeee3a</id>
<content type='text'>
ARM64 step exception does not have any syndrome information. So, it is
responsibility of exception handler to take care that they handle it
only if exception was raised for them.

Since kgdb_step_brk_fn() always returns 0, therefore we might have problem
when we will have other step handler registered as well.

This patch fixes kgdb_step_brk_fn() to return error in case of step handler
was not meant for kgdb.

Signed-off-by: Pratyush Anand &lt;panand@redhat.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
</entry>
</feed>
