Webkit's JIT compiler is incompatible with strong memory protections as provided by PAX. See debian bug report: http://bugs.debian.org/605132
Anyone interested in making this work should have two options here.
(1) turn on ASSEMBLER_WX_EXCLUSIVE. This may not be well tested lately in ToT, but will stop allocating WX memory.
(2) Set the flags in Platform.h to compile in both the JIT & the interpreter. If the JIT buffer allocation fails it should automatically fall back to use the JIT.
*** Bug 105730 has been marked as a duplicate of this bug. ***
*** Bug 147542 has been marked as a duplicate of this bug. ***