[PATCH v7 4/7] nmi: backtrace: Allow runtime arch specific override
Sumit Garg
sumit.garg at linaro.org
Tue Jan 5 05:32:14 EST 2021
Hello arch maintainers,
On Mon, 2 Nov 2020 at 17:16, Sumit Garg <sumit.garg at linaro.org> wrote:
>
> Add a boolean return to arch_trigger_cpumask_backtrace() to support a
> use-case where a particular architecture detects at runtime if it supports
> NMI backtrace or it would like to fallback to default implementation using
> SMP cross-calls.
>
> Currently such an architecture example is arm64 supporting pseudo NMIs
> feature which is only available on platforms which have support for GICv3
> or later version.
>
> Signed-off-by: Sumit Garg <sumit.garg at linaro.org>
> ---
> arch/arm/include/asm/irq.h | 2 +-
> arch/arm/kernel/smp.c | 3 ++-
> arch/mips/include/asm/irq.h | 2 +-
> arch/mips/kernel/process.c | 3 ++-
> arch/powerpc/include/asm/nmi.h | 2 +-
> arch/powerpc/kernel/stacktrace.c | 3 ++-
> arch/sparc/include/asm/irq_64.h | 2 +-
> arch/sparc/kernel/process_64.c | 4 +++-
> arch/x86/include/asm/irq.h | 2 +-
> arch/x86/kernel/apic/hw_nmi.c | 3 ++-
> include/linux/nmi.h | 12 ++++--------
> 11 files changed, 20 insertions(+), 18 deletions(-)
Do you have any comments here? It would be nice to have your ack here.
-Sumit
>
> diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h
> index 46d4114..54b0180 100644
> --- a/arch/arm/include/asm/irq.h
> +++ b/arch/arm/include/asm/irq.h
> @@ -31,7 +31,7 @@ void handle_IRQ(unsigned int, struct pt_regs *);
> void init_IRQ(void);
>
> #ifdef CONFIG_SMP
> -extern void arch_trigger_cpumask_backtrace(const cpumask_t *mask,
> +extern bool arch_trigger_cpumask_backtrace(const cpumask_t *mask,
> bool exclude_self);
> #define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
> #endif
> diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
> index 48099c6e..bb20a43 100644
> --- a/arch/arm/kernel/smp.c
> +++ b/arch/arm/kernel/smp.c
> @@ -856,7 +856,8 @@ static void raise_nmi(cpumask_t *mask)
> __ipi_send_mask(ipi_desc[IPI_CPU_BACKTRACE], mask);
> }
>
> -void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
> +bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
> {
> nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_nmi);
> + return true;
> }
> diff --git a/arch/mips/include/asm/irq.h b/arch/mips/include/asm/irq.h
> index c5d3517..34f3b42 100644
> --- a/arch/mips/include/asm/irq.h
> +++ b/arch/mips/include/asm/irq.h
> @@ -78,7 +78,7 @@ extern int cp0_fdc_irq;
>
> extern int get_c0_fdc_int(void);
>
> -void arch_trigger_cpumask_backtrace(const struct cpumask *mask,
> +bool arch_trigger_cpumask_backtrace(const struct cpumask *mask,
> bool exclude_self);
> #define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
>
> diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c
> index 75ebd8d..d19e672 100644
> --- a/arch/mips/kernel/process.c
> +++ b/arch/mips/kernel/process.c
> @@ -735,9 +735,10 @@ static void raise_backtrace(cpumask_t *mask)
> }
> }
>
> -void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
> +bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
> {
> nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace);
> + return true;
> }
>
> int mips_get_process_fp_mode(struct task_struct *task)
> diff --git a/arch/powerpc/include/asm/nmi.h b/arch/powerpc/include/asm/nmi.h
> index 84b4cfe..a5eb3e2 100644
> --- a/arch/powerpc/include/asm/nmi.h
> +++ b/arch/powerpc/include/asm/nmi.h
> @@ -9,7 +9,7 @@ static inline void arch_touch_nmi_watchdog(void) {}
> #endif
>
> #if defined(CONFIG_NMI_IPI) && defined(CONFIG_STACKTRACE)
> -extern void arch_trigger_cpumask_backtrace(const cpumask_t *mask,
> +extern bool arch_trigger_cpumask_backtrace(const cpumask_t *mask,
> bool exclude_self);
> #define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
> #endif
> diff --git a/arch/powerpc/kernel/stacktrace.c b/arch/powerpc/kernel/stacktrace.c
> index b644065..22b112a 100644
> --- a/arch/powerpc/kernel/stacktrace.c
> +++ b/arch/powerpc/kernel/stacktrace.c
> @@ -264,8 +264,9 @@ static void raise_backtrace_ipi(cpumask_t *mask)
> }
> }
>
> -void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
> +bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
> {
> nmi_trigger_cpumask_backtrace(mask, exclude_self, raise_backtrace_ipi);
> + return true;
> }
> #endif /* defined(CONFIG_PPC_BOOK3S_64) && defined(CONFIG_NMI_IPI) */
> diff --git a/arch/sparc/include/asm/irq_64.h b/arch/sparc/include/asm/irq_64.h
> index 4d748e9..35c01ff 100644
> --- a/arch/sparc/include/asm/irq_64.h
> +++ b/arch/sparc/include/asm/irq_64.h
> @@ -87,7 +87,7 @@ static inline unsigned long get_softint(void)
> return retval;
> }
>
> -void arch_trigger_cpumask_backtrace(const struct cpumask *mask,
> +bool arch_trigger_cpumask_backtrace(const struct cpumask *mask,
> bool exclude_self);
> #define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
>
> diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
> index a75093b..9182001 100644
> --- a/arch/sparc/kernel/process_64.c
> +++ b/arch/sparc/kernel/process_64.c
> @@ -248,7 +248,7 @@ static void __global_reg_poll(struct global_reg_snapshot *gp)
> }
> }
>
> -void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
> +bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
> {
> struct thread_info *tp = current_thread_info();
> struct pt_regs *regs = get_irq_regs();
> @@ -303,6 +303,8 @@ void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
> memset(global_cpu_snapshot, 0, sizeof(global_cpu_snapshot));
>
> spin_unlock_irqrestore(&global_cpu_snapshot_lock, flags);
> +
> + return true;
> }
>
> #ifdef CONFIG_MAGIC_SYSRQ
> diff --git a/arch/x86/include/asm/irq.h b/arch/x86/include/asm/irq.h
> index 528c8a7..b7668e0 100644
> --- a/arch/x86/include/asm/irq.h
> +++ b/arch/x86/include/asm/irq.h
> @@ -47,7 +47,7 @@ extern void init_ISA_irqs(void);
> extern void __init init_IRQ(void);
>
> #ifdef CONFIG_X86_LOCAL_APIC
> -void arch_trigger_cpumask_backtrace(const struct cpumask *mask,
> +bool arch_trigger_cpumask_backtrace(const struct cpumask *mask,
> bool exclude_self);
>
> #define arch_trigger_cpumask_backtrace arch_trigger_cpumask_backtrace
> diff --git a/arch/x86/kernel/apic/hw_nmi.c b/arch/x86/kernel/apic/hw_nmi.c
> index 34a992e..e7dcd28 100644
> --- a/arch/x86/kernel/apic/hw_nmi.c
> +++ b/arch/x86/kernel/apic/hw_nmi.c
> @@ -34,10 +34,11 @@ static void nmi_raise_cpu_backtrace(cpumask_t *mask)
> apic->send_IPI_mask(mask, NMI_VECTOR);
> }
>
> -void arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
> +bool arch_trigger_cpumask_backtrace(const cpumask_t *mask, bool exclude_self)
> {
> nmi_trigger_cpumask_backtrace(mask, exclude_self,
> nmi_raise_cpu_backtrace);
> + return true;
> }
>
> static int nmi_cpu_backtrace_handler(unsigned int cmd, struct pt_regs *regs)
> diff --git a/include/linux/nmi.h b/include/linux/nmi.h
> index 750c7f3..cedbfc1 100644
> --- a/include/linux/nmi.h
> +++ b/include/linux/nmi.h
> @@ -143,26 +143,22 @@ static inline void touch_nmi_watchdog(void)
> #ifdef arch_trigger_cpumask_backtrace
> static inline bool trigger_all_cpu_backtrace(void)
> {
> - arch_trigger_cpumask_backtrace(cpu_online_mask, false);
> - return true;
> + return arch_trigger_cpumask_backtrace(cpu_online_mask, false);
> }
>
> static inline bool trigger_allbutself_cpu_backtrace(void)
> {
> - arch_trigger_cpumask_backtrace(cpu_online_mask, true);
> - return true;
> + return arch_trigger_cpumask_backtrace(cpu_online_mask, true);
> }
>
> static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
> {
> - arch_trigger_cpumask_backtrace(mask, false);
> - return true;
> + return arch_trigger_cpumask_backtrace(mask, false);
> }
>
> static inline bool trigger_single_cpu_backtrace(int cpu)
> {
> - arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
> - return true;
> + return arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
> }
>
> /* generic implementation */
> --
> 2.7.4
>
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