GCC 4.3.0 exposes a kernel bug
Posted Mar 7, 2008 22:27 UTC (Fri) by JoeBuck
In reply to: GCC 4.3.0 exposes a kernel bug
Parent article: GCC 4.3.0 exposes a kernel bug
From the gcc point of view, it was simply a matter of observing that the compiler was emitting an unneeded instruction: we don't have to clear that register because it's already cleared; the standard says so, and real implementations follow the standard correctly (or so it was thought). The result was that code sequences that use the x86 string instructions are slightly smaller and faster with gcc 4.3.0.
The issue of kernels not following the rules in the case of signal handlers was not noticed until the 4.3.0 release process had already started.
If you think that kernel developers should be notified of every change of this kind, just in case it does something, they'd need to subscribe to the svn commit mailing list, and they'd be overwhelmed with messages describing small changes.
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