Re: V3.10-rc1 memory leak

[Catalin Marinas <catalin.marinas@arm.com>]

Hi Steve,

On Tue, May 14, 2013 at 08:09:46PM +0100, Steven Rostedt wrote:
> # find /debug/tracing/events/ -name format |xargs grep ffff8800769f7438
> /debug/tracing/events/drm/drm_vblank_event_delivered/format:	field:pid_t pid;	offset:8;	size:4;	signed:1;ffff8800769f7438
> 
> Thus, what it is complaining about being leaked, is currently being
> used.
> 
> I guess it's because the fields are stored on the "event class"
> structure of the module. That is, the struct ftrace_event_class, which
> is part of the module data section:
> 
> struct ftrace_event_class {
>         char                    *system;
>         void                    *probe;
> #ifdef CONFIG_PERF_EVENTS
>         void                    *perf_probe;
> #endif
>         int                     (*reg)(struct ftrace_event_call *event,
>                                        enum trace_reg type, void *data);
>         int                     (*define_fields)(struct ftrace_event_call *);
>         struct list_head        *(*get_fields)(struct ftrace_event_call *);
>         struct list_head        fields;
>         int                     (*raw_init)(struct ftrace_event_call *);
> };
> 
> 
> The list_head fields holds the fields and these are used to print out
> the formats. For some reason, kmemleak is missing that the fields are
> being assigned to this list on module load.
> 
> Catalin, have any idea why kmemleak is not detecting that the field is
> being referenced?

I just got a patch today:

https://lkml.org/lkml/2013/5/10/607

which could be related. If Rusty doesn't push it I'll do. But please let
me know if it does not solve the problem.

Thanks.

-- 
Catalin