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

[Alexander Potapenko]

On the other hand, this will require including <linux/irq.h> into
various files that currently use __irq_section.
But that header has a comment saying:

/*
 * Please do not include this file in generic code.  There is currently
 * no requirement for any architecture to implement anything held
 * within this file.
 *
 * Thanks. --rmk
 */

Do we really want to put anything into that header?

On Fri, Jan 29, 2016 at 12:33 PM, Alexander Potapenko <glider@xxxxxxxxxx> wrote:
> Agreed. Once I receive more comments I will make a new patch set and
> include this change as well.
>
> On Thu, Jan 28, 2016 at 3:53 PM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
>> 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
>>
>
>
>
> --
> Alexander Potapenko
> Software Engineer
>
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-- 
Alexander Potapenko
Software Engineer

Google Germany GmbH
Erika-Mann-StraÃe, 33
80636 MÃnchen

GeschÃftsfÃhrer: Matthew Scott Sucherman, Paul Terence Manicle
Registergericht und -nummer: Hamburg, HRB 86891
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