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authorPaul Burton <paul.burton@mips.com>2018-06-22 10:55:45 -0700
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-17 11:37:51 +0200
commit473b33dd615f35c0bad13737def7751fb089ce60 (patch)
treeb2142e3a6272e2e11cee64fb7e2b6cd623b381a7
parent93e54f40c89336adc28b4125529bb75d4b565a70 (diff)
downloadlinux-linaro-stable-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.c4
-rw-r--r--arch/mips/kernel/traps.c1
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)