Ralf Baechle wrote:
There is no hazard barrier between writes to c0_context and subsequent
read accesses. This is a fairly theoretical hole as c0_context is only
written on CPU bootup and other, unrelated code will almost certainly
It was actually in the bootup code where I saw the problem, and this
patch doesn't deal with that case:
MTC0 zero, CP0_CONTEXT # clear context register
PTR_LA $28, init_thread_union
/* Set the SP after an empty pt_regs. */
PTR_LI sp, _THREAD_SIZE - 32 - PT_SIZE
PTR_ADDU sp, $28
back_to_back_c0_hazard
set_saved_sp sp, t0, t1
The problem I observed is that the Context valuse used by set_saved_sp
is whatever it inherits from YAMON.
Chris
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Chris Dearman Desk: +1 408 530 5092 Cell: +1 650 224 8603
MIPS Technologies Inc 955 East Arques Ave, Sunnyvale CA 94085
