Re: [v3 PATCH 1/3] panic: Change nmi_panic from macro to function

From: Michal Nazarewicz
Date: Fri Mar 04 2016 - 14:27:51 EST


On Thu, Mar 03 2016, Hidehiro Kawai wrote:
> Change nmi_panic() macro to a normal function for the portability.
> Also, export it for modules.
>
> Changes since v2:
> - Make nmi_panic receive a single string instead of printf style args
>
> Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@xxxxxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxx>
> Cc: Michal Nazarewicz <mina86@xxxxxxxxxx>

Code does what the commit advertises so

Acked-by: Michal Nazarewicz <mina86@xxxxxxxxxx>

> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
> Cc: Nicolas Iooss <nicolas.iooss_linux@xxxxxxx>
> Cc: Javi Merino <javi.merino@xxxxxxx>
> Cc: Gobinda Charan Maji <gobinda.cemk07@xxxxxxxxx>
> Cc: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
> Cc: HATAYAMA Daisuke <d.hatayama@xxxxxxxxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>
> ---
> include/linux/kernel.h | 21 +-------------------
> kernel/panic.c | 20 ++++++++++++++++++++
> 2 files changed, 21 insertions(+), 20 deletions(-)
>
> diff --git a/include/linux/kernel.h b/include/linux/kernel.h
> index f31638c..cbe7d70 100644
> --- a/include/linux/kernel.h
> +++ b/include/linux/kernel.h
> @@ -255,7 +255,7 @@ extern long (*panic_blink)(int state);
> __printf(1, 2)
> void panic(const char *fmt, ...)
> __noreturn __cold;
> -void nmi_panic_self_stop(struct pt_regs *);
> +void nmi_panic(struct pt_regs *regs, const char *msg);
> extern void oops_enter(void);
> extern void oops_exit(void);
> void print_oops_end_marker(void);
> @@ -455,25 +455,6 @@ extern atomic_t panic_cpu;
> #define PANIC_CPU_INVALID -1
>
> /*
> - * A variant of panic() called from NMI context. We return if we've already
> - * panicked on this CPU. If another CPU already panicked, loop in
> - * nmi_panic_self_stop() which can provide architecture dependent code such
> - * as saving register state for crash dump.
> - */
> -#define nmi_panic(regs, fmt, ...) \
> -do { \
> - int old_cpu, cpu; \
> - \
> - cpu = raw_smp_processor_id(); \
> - old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu); \
> - \
> - if (old_cpu == PANIC_CPU_INVALID) \
> - panic(fmt, ##__VA_ARGS__); \
> - else if (old_cpu != cpu) \
> - nmi_panic_self_stop(regs); \
> -} while (0)
> -
> -/*
> * Only to be used by arch init code. If the user over-wrote the default
> * CONFIG_PANIC_TIMEOUT, honor it.
> */
> diff --git a/kernel/panic.c b/kernel/panic.c
> index d96469d..8abfc30 100644
> --- a/kernel/panic.c
> +++ b/kernel/panic.c
> @@ -72,6 +72,26 @@ void __weak nmi_panic_self_stop(struct pt_regs *regs)
>
> atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
>
> +/*
> + * A variant of panic() called from NMI context. We return if we've already
> + * panicked on this CPU. If another CPU already panicked, loop in
> + * nmi_panic_self_stop() which can provide architecture dependent code such
> + * as saving register state for crash dump.
> + */
> +void nmi_panic(struct pt_regs *regs, const char *msg)
> +{
> + int old_cpu, cpu;
> +
> + cpu = raw_smp_processor_id();
> + old_cpu = atomic_cmpxchg(&panic_cpu, PANIC_CPU_INVALID, cpu);
> +
> + if (old_cpu == PANIC_CPU_INVALID)
> + panic("%s", msg);
> + else if (old_cpu != cpu)
> + nmi_panic_self_stop(regs);
> +}
> +EXPORT_SYMBOL(nmi_panic);
> +
> /**
> * panic - halt the system
> * @fmt: The text string to print
>
>

--
Best regards
ããã âðððð86â ãããããã
ÂIf at first you donât succeed, give up skydivingÂ