diff options
| author | Paul Burton <paul.burton@mips.com> | 2018-06-22 10:55:45 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-07-17 11:37:51 +0200 |
| commit | 473b33dd615f35c0bad13737def7751fb089ce60 (patch) | |
| tree | b2142e3a6272e2e11cee64fb7e2b6cd623b381a7 | |
| parent | 93e54f40c89336adc28b4125529bb75d4b565a70 (diff) | |
| download | linux-rt-473b33dd615f35c0bad13737def7751fb089ce60.tar.gz | |
MIPS: Call dump_stack() from show_regs()
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 <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19596/
Cc: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Huacai Chen <chenhc@lemote.com>
Cc: linux-mips@linux-mips.org
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/mips/kernel/process.c | 4 | ||||
| -rw-r--r-- | arch/mips/kernel/traps.c | 1 |
2 files changed, 3 insertions, 2 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index ebb575c4231b..cb1e9c184b5a 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -641,8 +641,8 @@ static void arch_dump_stack(void *info) if (regs) show_regs(regs); - - dump_stack(); + else + dump_stack(); } void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index bb1d9ff1be5c..8e0749665934 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -351,6 +351,7 @@ static void __show_regs(const struct pt_regs *regs) void show_regs(struct pt_regs *regs) { __show_regs((struct pt_regs *)regs); + dump_stack(); } void show_registers(struct pt_regs *regs) |