Re: [rtla 01/13] rtla: Check for memory allocation failures

[Steven Rostedt]

On Tue, 18 Nov 2025 11:09:46 +0900
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx> wrote:

> On Mon, 17 Nov 2025 15:41:08 -0300
> Wander Lairson Costa <wander@xxxxxxxxxx> wrote:
> 
> > The actions_init() and actions_new() functions did not check the
> > return value of calloc() and realloc() respectively. In a low
> > memory situation, this could lead to a NULL pointer dereference.
> > 
> > Add checks for the return value of memory allocation functions
> > and return an error in case of failure. Update the callers to
> > handle the error properly.
> > 
> > Signed-off-by: Wander Lairson Costa <wander@xxxxxxxxxx>
> > ---
> >  tools/tracing/rtla/src/actions.c       | 26 +++++++++++++++++++++++---
> >  tools/tracing/rtla/src/actions.h       |  2 +-
> >  tools/tracing/rtla/src/timerlat_hist.c |  7 +++++--
> >  tools/tracing/rtla/src/timerlat_top.c  |  7 +++++--
> >  4 files changed, 34 insertions(+), 8 deletions(-)
> > 
> > diff --git a/tools/tracing/rtla/src/actions.c b/tools/tracing/rtla/src/actions.c
> > index 8945aee58d511..01648a1425c10 100644
> > --- a/tools/tracing/rtla/src/actions.c
> > +++ b/tools/tracing/rtla/src/actions.c
> > @@ -11,11 +11,13 @@
> >  /*
> >   * actions_init - initialize struct actions
> >   */
> > -void
> > +int
> >  actions_init(struct actions *self)
> >  {
> >  	self->size = action_default_size;
> >  	self->list = calloc(self->size, sizeof(struct action));
> > +	if (!self->list)
> > +		return -1;  
> 
> Can you return -ENOMEM?

Does it need to? This is user space not the kernel. Errno is already
set by calloc() failing.

-- Steve