On Thu, May 25, 2017 at 04:42:16PM +0100, Catalin Marinas wrote: > The scan_block() function updates the number of references (pointers) to > objects, adding them to the gray_list when object->min_count is reached. > The patch factors out this functionality into a separate update_refs() > function. > > Cc: Michal Hocko <[email protected]> > Cc: Andy Lutomirski <[email protected]> > Cc: "Luis R. Rodriguez" <[email protected]> > Signed-off-by: Catalin Marinas <[email protected]> > --- > mm/kmemleak.c | 43 +++++++++++++++++++++++++------------------ > 1 file changed, 25 insertions(+), 18 deletions(-) > > diff --git a/mm/kmemleak.c b/mm/kmemleak.c > index 964b12eba2c1..266482f460c2 100644 > --- a/mm/kmemleak.c > +++ b/mm/kmemleak.c > @@ -1188,6 +1188,30 @@ static bool update_checksum(struct kmemleak_object > *object) > } > > /* > + * Update an object's references. object->lock must be held by the caller. > + */ > +static void update_refs(struct kmemleak_object *object) > +{ > + if (!color_white(object)) { > + /* non-orphan, ignored or new */ > + return; > + } > + > + /* > + * Increase the object's reference count (number of pointers to the > + * memory block). If this count reaches the required minimum, the > + * object's color will become gray and it will be added to the > + * gray_list. > + */ > + object->count++; > + if (color_gray(object)) { > + /* put_object() called when removing from gray_list */ > + WARN_ON(!get_object(object)); > + list_add_tail(&object->gray_list, &gray_list); > + } > +} > + > +/* > * Memory scanning is a long process and it needs to be interruptable. This > * function checks whether such interrupt condition occurred. > */ > @@ -1259,24 +1283,7 @@ static void scan_block(void *_start, void *_end, > * enclosed by scan_mutex. > */ > spin_lock_nested(&object->lock, SINGLE_DEPTH_NESTING); > - if (!color_white(object)) { > - /* non-orphan, ignored or new */ > - spin_unlock(&object->lock); > - continue; > - } > - > - /* > - * Increase the object's reference count (number of pointers > - * to the memory block). If this count reaches the required > - * minimum, the object's color will become gray and it will be > - * added to the gray_list. > - */ > - object->count++; > - if (color_gray(object)) { > - /* put_object() called when removing from gray_list */ > - WARN_ON(!get_object(object)); > - list_add_tail(&object->gray_list, &gray_list); > - } > + update_refs(object); > spin_unlock(&object->lock);
FWIW, I've tested this patchset and I don't see kmemleak triggering the false positives anymore. I've also done a quick review and couldn't find anything obviously incorrect, just a question: why didn't you moved the spin_lock/unlock into update_refs() too? It would save you 2 lines in the next patch :) Cheers, -- Luís > } > read_unlock_irqrestore(&kmemleak_lock, flags); >
