[Webkit-unassigned] [Bug 157338] REGRESSION(r200383): All layout and API tests crash in GTK+ debug bot after r200383

[bugzilla-daemon at webkit.org]

https://bugs.webkit.org/show_bug.cgi?id=157338

Zan Dobersek <zan at falconsigh.net> changed:

           What    |Removed                     |Added
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                 CC|                            |zan at falconsigh.net
             Blocks|157045                      |

--- Comment #4 from Zan Dobersek <zan at falconsigh.net> ---
The callFunc functions that are instantiated must be aligned to the minimum supported value so that the two tags can be encoded into the bottom two bits of the pointer value.

This isn't the case in builds with GCC that don't at least use  -O2 -- -falign-functions is disabled then, and callFunc address can have the second-lowest bit always set. Lazy initialization in callFunc<>() then fails because the pointer value always seems to encode the initialization tag, returning early and not initializing anything.

The simplest way to deal with this would be to slap a aligned() attribute onto the static function declaration.

Only tested on x86-64. ARM Thumb2 probably suffers from the same issue, but AFAIU this is occurring even in release builds where -falign-functions should be enabled.

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