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| author | Paul Burton <paul.burton@mips.com> | 2018-06-22 20:55:45 +0300 |
|---|---|---|
| committer | Paul Burton <paul.burton@mips.com> | 2018-06-28 21:48:54 +0300 |
| commit | 5a267832c2ec47b2dad0fdb291a96bb5b8869315 (patch) | |
| tree | 49366e977a2cc6fc995117aae5444a924a2c0e2d /arch/mips/kernel | |
| parent | 662d855c66c0a7400f9117b6ac02047942cd1d22 (diff) | |
| download | linux-5a267832c2ec47b2dad0fdb291a96bb5b8869315.tar.xz | |
MIPS: Call dump_stack() from show_regs()
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+
Diffstat (limited to 'arch/mips/kernel')
| -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 8d85046adcc8..d4cfeb931382 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -663,8 +663,8 @@ 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 d67fa74622ee..8d505a21396e 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) |