If the FPU registers are otherwise preserved across a system call,
they should be copied by fork(). Otherwise it will not work
properly if you use floating point in the same routine that does a
fork() (remember, to the C compiler, fork() is just another
function.)
Most ABI's I've seen say FPU regs are clobbered across a function
call, or some subset of them are. And the same holds for system
calls. The one case to be careful about, as Xavier has mentioned, is
the FPU control register.
Later,
David S. Miller
davem@dm.cobaltmicro.com
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