1899874 - Implement forceSoftwareRendering for canvas contextes

Status: RESOLVED FIXED

(Core :: Privacy: Anti-Tracking, enhancement)

Description

[Tom Ritter [:tjr]]

In addition to Bug 1894958, we would like to collect the same canvases; rendered with software rendering. We have long assumed that software-rendering canvases would remove entropy from the result; but we need to validate this.

Comment 1

[Tom Ritter [:tjr]]

Attachment: Bug 1899874: Add a privileged forceSoftwareRendering attribute to Canvas Attributes. r?jgilbert

willReadFrequently does basically what we want for Canvas2D;
however it won't work on Windows and it doesn't exist for WebGL

So we will just add our own (privileged) attribute we can set

Comment 2

[Tom Ritter [:tjr]]

Attachment: Bug 1899874: Plumb forceSoftwareRendering down the stack. r?jgilbert

willReadFrequently already implies this; however that can't
be enabled on Windows. We can use our own attribute to control
the value as it plumbs into the depths of Canvas2D

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/b73df6e562de
Add a privileged forceSoftwareRendering attribute to Canvas Attributes. r=jgilbert,webidl,smaug
https://hg.mozilla.org/integration/autoland/rev/693209b2919f
Plumb forceSoftwareRendering down the stack. r=jgilbert

Comment 4

[Serban Stanca [:SerbanS]]

Backed out for causing multiple failures.

• Backout link

---

• Push with failures - build bustages
• Failure Log
• Failure line: /builds/worker/checkouts/gecko/gfx/gl/GLContextProviderWGL.cpp(475,8): error: no viable conversion from 'mozilla::CastableTypedEnumResult<CreateContextFlags>' to 'bool'

---

• Push with failures - leak failures
• Failure Log
• Failure line: TEST-UNEXPECTED-FAIL | leakcheck | tab 232 bytes leaked (Mutex, StringBuffer, nsJSPrincipals, nsSimpleURI)

---

• Push with failures - reftests failures
• Failure Log
• Failure line: Assertion failure: NS_IsMainThread(), at /builds/worker/checkouts/gecko/dom/base/nsContentUtils.cpp:3616

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/347c3fe4a18f
Add a privileged forceSoftwareRendering attribute to Canvas Attributes. r=jgilbert,webidl,smaug
https://hg.mozilla.org/integration/autoland/rev/cd0e7d18bbff
Plumb forceSoftwareRendering down the stack. r=jgilbert

Comment 6

[pstanciu]

https://hg.mozilla.org/mozilla-central/rev/347c3fe4a18f
https://hg.mozilla.org/mozilla-central/rev/cd0e7d18bbff

Comment 7

[Cristian Tuns]

Backed out, It is crashing the browser on windows and linux, Bug 1906687.

• Backout link

Comment 8

[Serban Stanca [:SerbanS]]

Backout merged in central: https://hg.mozilla.org/mozilla-central/rev/a8c9a7b30e1d6d94af346771559847a296b82b71

Comment 9

[Fatih Kilic [:fkilic]]

Updated revisions to fix the crashing issue. Thank you!

Comment 10

[Donal Meehan [:dmeehan]]

Backout uplifted to beta: https://hg.mozilla.org/releases/mozilla-beta/rev/21e46c6e9c1ba42028495c6f66acc9fe3674674d

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0755e1ce963d
Add a privileged forceSoftwareRendering attribute to Canvas Attributes. r=jgilbert,webidl,smaug
https://hg.mozilla.org/integration/autoland/rev/373176b6f4ad
Plumb forceSoftwareRendering down the stack. r=jgilbert

Comment 12

[Cristina Horotan [:chorotan]]

https://hg.mozilla.org/mozilla-central/rev/0755e1ce963d
https://hg.mozilla.org/mozilla-central/rev/373176b6f4ad

Comment 13

[BugBot [:suhaib / :marco/ :calixte]]

Since nightly and release are affected, beta will likely be affected too.
For more information, please visit BugBot documentation.

Comment 14

[Mathew Hodson]

Was backed out of Firefox 129