Re: Memory corruption due to word sharing

From: David Miller
Date: Wed Feb 01 2012 - 13:11:34 EST


From: Michael Matz <matz@xxxxxxx>
Date: Wed, 1 Feb 2012 18:41:05 +0100 (CET)

> One problem is that it's not a new problem, GCC emitted similar code since
> about forever, and still they turned up only now (well, probably because
> ia64 is dead, but sparc64 should have similar problems).

Indeed, on sparc64 it does do the silly 64-bit access too:

wrong:
ldx [%o0+8], %g2
sethi %hi(2147483648), %g1
or %g2, %g1, %g1
jmp %o7+8
stx %g1, [%o0+8]

Personally I've avoided C bitfields like the plague in any code I've
written.
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