1506311 - Refine filtering of CGColorSpaceCreateDevice symbols where redirection instructions can be installed

Status: RESOLVED FIXED

(Core Graveyard :: Web Replay, defect)

Description

[Brian Hackett [Laid off!]]

Attachment: patch

Bug 1505922 adds a redirection for CGColorSpaceCreateDeviceGray, but on 10.13.6 this redirection is unable to be installed; thanks to the diagnostic logging in bug 1506280, this is shown to be because we could not find a place to patch long jumps for the redirection that are in range of a short jump at the start of CGColorSpaceCreateDeviceGray.  The logs indicate that we are, however, skipping over __CGColorSpaceCreateDeviceGray_block_invoke, a large and uncomplicated block of code that is a great place to stick some redirection jumps.

We skip over this because the filter that prevents us from inserting a long jump at the start of CGColorSpaceCreateDeviceGray (it has a backedge which will be corrupted if we insert the long jump) also matches against __CGColorSpaceCreateDeviceGray_block_invoke.

The attached patch fixes this filter so it only matches against the backedge-containing symbol, CGColorSpaceCreateDeviceGray.  A similar case in CGColorSpaceCreateDeviceRGB is also handled.

Comment 1

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/611ca008b6be
Refine filtering of CGColorSpaceCreateDevice symbols where redirection instructions can be installed.

Comment 2

[Brian Hackett [Laid off!]]

Nightly is still broken on 10.13 because of bug 1505922, so landing this now to unbreak things.

Comment 3

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/611ca008b6be