[lkml]   [2018]   [Jul]   [20]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 4.4 26/31] MIPS: Call dump_stack() from show_regs()
4.4-stable review patch.  If anyone has any objections, please let me know.


From: Paul Burton <>

commit 5a267832c2ec47b2dad0fdb291a96bb5b8869315 upstream.

The generic nmi_cpu_backtrace() function calls show_regs() when a struct
pt_regs is available, and dump_stack() otherwise. If we were to make use
of the generic nmi_cpu_backtrace() with MIPS' current implementation of
show_regs() this would mean that we see only register data with no
accompanying stack information, in contrast with our current
implementation which calls dump_stack() regardless of whether register
state is available.

In preparation for making use of the generic nmi_cpu_backtrace() to
implement arch_trigger_cpumask_backtrace(), have our implementation of
show_regs() call dump_stack() and drop the explicit dump_stack() call in
arch_dump_stack() which is invoked by arch_trigger_cpumask_backtrace().

This will allow the output we produce to remain the same after a later
patch switches to using nmi_cpu_backtrace(). It may mean that we produce
extra stack output in other uses of show_regs(), but this:

1) Seems harmless.
2) Is good for consistency between arch_trigger_cpumask_backtrace()
and other users of show_regs().
3) Matches the behaviour of the ARM & PowerPC architectures.

Marked for stable back to v4.9 as a prerequisite of the following patch
"MIPS: Call dump_stack() from show_regs()".

Signed-off-by: Paul Burton <>
Cc: James Hogan <>
Cc: Ralf Baechle <>
Cc: Huacai Chen <>
Cc: # v4.9+
Signed-off-by: Huacai Chen <>
Signed-off-by: Greg Kroah-Hartman <>

arch/mips/kernel/process.c | 4 ++--
arch/mips/kernel/traps.c | 1 +
2 files changed, 3 insertions(+), 2 deletions(-)

--- a/arch/mips/kernel/process.c
+++ b/arch/mips/kernel/process.c
@@ -637,8 +637,8 @@ static void arch_dump_stack(void *info)

if (regs)
- dump_stack();
+ else
+ dump_stack();

void arch_trigger_all_cpu_backtrace(bool include_self)
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -344,6 +344,7 @@ static void __show_regs(const struct pt_
void show_regs(struct pt_regs *regs)
__show_regs((struct pt_regs *)regs);
+ dump_stack();

void show_registers(struct pt_regs *regs)

 \ /
  Last update: 2018-07-20 14:59    [W:0.149 / U:8.504 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site