1167531 - Uninitialised value uses relating to GonkDisplayJB::GonkDisplayJB

Status: RESOLVED FIXED

(Core Graveyard :: Widget: Gonk, defect)

Description

[Julian Seward [:jseward]]

GonkDisplayJB::GonkDisplayJB allocates a secondary structure

GonkDisplayJB.cpp:132
    mList = (hwc_display_contents_1_t *)malloc(sizeof(*mList) + (sizeof(hwc_layer_1_t)*2));

Some but not all of mList's many fields are filled in in GonkDisplayJB::Post.
It appears that some of these fields (5, I suspect) are used uninitialised
shortly thereafter.

Comment 1

[Julian Seward [:jseward]]

Attachment: Valgrind complaints

Comment 2

[Julian Seward [:jseward]]

Attachment: bug1167531-1.diff

* Allocates mList using calloc so as to ensure that all fields are defined

* [optional cleanup] sets GonkDisplayJB::{mWidth,mHeight} right at the
  start of GonkDisplayJB::GonkDisplayJB so as to make it obvious to all
  that these fields have an initial value regardless of the control flow
  in the constructor body.

Comment 3

[Pulsebot]

https://hg.mozilla.org/integration/mozilla-inbound/rev/ec2a1ba41a7a

Comment 4

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/ec2a1ba41a7a