On 08/25/2007 01:31 PM, Clark Cooper wrote: >> Your handler can do this by masking >> exceptions, changing the operands of the failed FP instruction, >> or by changing the PC so that the failed instruction is skipped >> (your handler may want to emulate the instruction in this case). > > Given the current SIGFPE handling in the kernel, a userland handler > CAN'T mask the exceptions or clear the exception flags. This is > demonstrated in my example program where I call both feclearexception > and fedisableexception in the handler. The reason these don't work is > that any change you make to these FPU registers is overwritten with > the saved FPU context on return from the signal handler. Changing the > PC won't help since the exception flag is still set and unmasked on > signal return.
Just change the saved FPU context before returning. (It's on the stack when your handler is running.) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
