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| author | Takashi Iwai <tiwai@suse.de> | 2018-08-12 08:55:01 +0200 |
|---|---|---|
| committer | Takashi Iwai <tiwai@suse.de> | 2018-08-12 08:55:10 +0200 |
| commit | 73b383141d296c55bfbc0ce336a4a946627e7780 (patch) | |
| tree | df0840c4ea4bbd5aa453931a594936bd9adab61d /arch/mips/kernel/process.c | |
| parent | 627661ced8246c8e833f3bc3817070e934cd79ba (diff) | |
| parent | 91c6e15efc1756b068dc6e945c1626397e60a119 (diff) | |
| download | linux-73b383141d296c55bfbc0ce336a4a946627e7780.tar.bz2 | |
Merge branch 'for-next' into for-linus
Preparation for 4.19 merge material.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Diffstat (limited to 'arch/mips/kernel/process.c')
| -rw-r--r-- | arch/mips/kernel/process.c | 43 |
1 files changed, 29 insertions, 14 deletions
diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index 8d85046adcc8..9670e70139fd 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -29,6 +29,7 @@ #include <linux/kallsyms.h> #include <linux/random.h> #include <linux/prctl.h> +#include <linux/nmi.h> #include <asm/asm.h> #include <asm/bootinfo.h> @@ -655,28 +656,42 @@ unsigned long arch_align_stack(unsigned long sp) return sp & ALMASK; } -static void arch_dump_stack(void *info) +static DEFINE_PER_CPU(call_single_data_t, backtrace_csd); +static struct cpumask backtrace_csd_busy; + +static void handle_backtrace(void *info) { - struct pt_regs *regs; + nmi_cpu_backtrace(get_irq_regs()); + cpumask_clear_cpu(smp_processor_id(), &backtrace_csd_busy); +} - regs = get_irq_regs(); +static void raise_backtrace(cpumask_t *mask) +{ + call_single_data_t *csd; + int cpu; - if (regs) - show_regs(regs); + for_each_cpu(cpu, mask) { + /* + * If we previously sent an IPI to the target CPU & it hasn't + * cleared its bit in the busy cpumask then it didn't handle + * our previous IPI & it's not safe for us to reuse the + * call_single_data_t. + */ + if (cpumask_test_and_set_cpu(cpu, &backtrace_csd_busy)) { + pr_warn("Unable to send backtrace IPI to CPU%u - perhaps it hung?\n", + cpu); + continue; + } - dump_stack(); + csd = &per_cpu(backtrace_csd, cpu); + csd->func = handle_backtrace; + smp_call_function_single_async(cpu, csd); + } } void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self) { - long this_cpu = get_cpu(); - - if (cpumask_test_cpu(this_cpu, mask) && !exclude_self) - dump_stack(); - - smp_call_function_many(mask, arch_dump_stack, NULL, 1); - - put_cpu(); + nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace); } int mips_get_process_fp_mode(struct task_struct *task) |