Re: [PATCH v1 4/8] arch, ftrace: For KASAN put hard/soft IRQ entries into separate sections

From: Steven Rostedt
Date: Thu Jan 28 2016 - 09:53:56 EST


On Wed, 27 Jan 2016 19:25:09 +0100
Alexander Potapenko <glider@xxxxxxxxxx> wrote:

> --- a/include/linux/ftrace.h
> +++ b/include/linux/ftrace.h
> @@ -762,6 +762,26 @@ struct ftrace_graph_ret {
> typedef void (*trace_func_graph_ret_t)(struct ftrace_graph_ret *); /* return */
> typedef int (*trace_func_graph_ent_t)(struct ftrace_graph_ent *); /* entry */
>
> +#if defined(CONFIG_FUNCTION_GRAPH_TRACER) || defined(CONFIG_KASAN)
> +/*
> + * We want to know which function is an entrypoint of a hardirq.
> + */
> +#define __irq_entry __attribute__((__section__(".irqentry.text")))
> +#define __softirq_entry \
> + __attribute__((__section__(".softirqentry.text")))
> +
> +/* Limits of hardirq entrypoints */
> +extern char __irqentry_text_start[];
> +extern char __irqentry_text_end[];
> +/* Limits of softirq entrypoints */
> +extern char __softirqentry_text_start[];
> +extern char __softirqentry_text_end[];
> +
> +#else
> +#define __irq_entry
> +#define __softirq_entry
> +#endif
> +
> #ifdef CONFIG_FUNCTION_GRAPH_TRACER
>
> /* for init task */

Since this is no longer just used for function tracing, perhaps the
code should be moved to include/linux/irq.h or something.

-- Steve