linux-toradex.git/arch/arc/kernel/kgdb.c, branch v6.7

ARC: pt_regs: create seperate type for ecr

2023-08-18T17:30:47+00:00

Reduces duplication in each ISA specific pt_regs

Tested-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202308151342.ROQ9Urvv-lkp@intel.com
Signed-off-by: Vineet Gupta

ARC: kgdb: add 'fallthrough' to prevent a warning

2021-05-10T19:38:59+00:00

Use the 'fallthrough' macro to document that this switch case
does indeed fall through to the next case.

../arch/arc/kernel/kgdb.c: In function 'kgdb_arch_handle_exception':
../arch/arc/kernel/kgdb.c:141:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
  141 |   if (kgdb_hex2long(&ptr, &addr))
      |      ^
../arch/arc/kernel/kgdb.c:144:2: note: here
  144 |  case 'D':
      |  ^~~~

Cc: linux-snps-arc@lists.infradead.org
Signed-off-by: Randy Dunlap 
Signed-off-by: Vineet Gupta

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500

2019-06-19T15:09:55+00:00

Based on 2 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 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 #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner 
Reviewed-by: Enrico Weigelt 
Reviewed-by: Kate Stewart 
Reviewed-by: Allison Randal 
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman

kgdb/treewide: constify struct kgdb_arch arch_kgdb_ops

2018-12-30T08:33:06+00:00

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 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Yoshinori Sato 
Cc: Richard Kuo 
Cc: Michal Simek 
Cc: Ralf Baechle 
Cc: Paul Burton 
Cc: James Hogan 
Cc: Ley Foon Tan 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Rich Felker 
Cc: "David S. Miller" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: x86@kernel.org
Acked-by: Daniel Thompson 
Acked-by: Paul Burton 
Signed-off-by: Christophe Leroy 
Acked-by: Borislav Petkov 
Acked-by: Michael Ellerman  (powerpc)
Signed-off-by: Daniel Thompson

kgdb: Fix kgdb_roundup_cpus() for arches who used smp_call_function()

2018-12-30T08:28:02+00:00

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->hardirq_context)

Specifically it looked like this:
  sysrq: SysRq : DEBUG
  ------------[ cut here ]------------
  DEBUG_LOCKS_WARN_ON(current->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 
Signed-off-by: Douglas Anderson 
Cc: Vineet Gupta 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Richard Kuo 
Cc: Ralf Baechle 
Cc: Paul Burton 
Cc: James Hogan 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Yoshinori Sato 
Cc: Rich Felker 
Cc: "David S. Miller" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: "H. Peter Anvin" 
Acked-by: Will Deacon 
Signed-off-by: Daniel Thompson

kgdb: Remove irq flags from roundup

2018-12-30T08:24:21+00:00

The function kgdb_roundup_cpus() was passed a parameter that was
documented as:

> the flags that will be used when restoring the interrupts. There is
> 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 
Cc: Vineet Gupta 
Cc: Russell King 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Richard Kuo 
Cc: Ralf Baechle 
Cc: Paul Burton 
Cc: James Hogan 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Cc: Michael Ellerman 
Cc: Yoshinori Sato 
Cc: Rich Felker 
Cc: "David S. Miller" 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: Borislav Petkov 
Cc: "H. Peter Anvin" 
Acked-by: Will Deacon 
Signed-off-by: Daniel Thompson

sched/headers: Prepare for new header dependencies before moving code to

2017-03-02T07:42:36+00:00

We are going to split  out of , which
will have to be picked up from other headers and a couple of .c files.

Create a trivial placeholder  file that just
maps to  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 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

ARC: kgdb: generic kgdb_arch_pc() suffices

2014-10-22T22:14:04+00:00

The ARC version of kgdb_arch_pc() is identical to the generic version in
kernel/debug/debug_core.c.  Drop the ARC version so we use the generic one.

Signed-off-by: Vineet Gupta 
Signed-off-by: Bjorn Helgaas

arc: kgdb: add default implementation for kgdb_roundup_cpus()

2013-11-06T05:11:41+00:00

arc supports kgdb, but need update -- add function kgdb_roundup_cpus(),
or can not pass compiling. At present, add the simple generic one just
like other architectures(e.g. tile, mips ...).

The related error (with allmodconfig):

  kernel/built-in.o: In function `kgdb_cpu_enter':
  kernel/debug/debug_core.c:580: undefined reference to `kgdb_roundup_cpus'

Signed-off-by: Chen Gang 
Signed-off-by: Vineet Gupta

ARC: Remove explicit passing around of ECR

2013-06-26T10:00:50+00:00

With ECR now part of pt_regs

* No need to propagate from lowest asm handlers as arg
* No need to save it in tsk->thread.cause_code
* Avoid bit chopping to access the bit-fields

More code consolidation, cleanup

Signed-off-by: Vineet Gupta