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For non MIPSr2 processors, such as the BMIPS 5000, calls to arch_local_irq_disable() and others may be preempted, and in doing so a stale value may be restored to c0_status. This fix disables preemption for such processors prior to the call and enables it after the call. Those functions that needed this fix have been "outlined" to mips-atomic.c, as they are no longer good candidates for inlining. This bug was observed in a BMIPS 5000, occuring once every few hours in a continuous reboot test. It was traced to the write_lock_irq() function which was being invoked in release_task() in exit.c. By placing a number of "nops" inbetween the mfc0/mtc0 pair in arch_local_irq_disable(), which is called by write_lock_irq(), we were able to greatly increase the occurance of this bug. Similarly, the application of this commit silenced the bug. Signed-off-by: Jim Quinlan <jim2101024@gmail.com> Cc: linux-mips@linux-mips.org Cc: David Daney <ddaney.cavm@gmail.com> Cc: Kevin Cernekee cernekee@gmail.com Cc: Jim Quinlan <jim2101024@gmail.com> Patchwork: https://patchwork.linux-mips.org/patch/4321/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> |
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| .. | ||
| ashldi3.c | ||
| ashrdi3.c | ||
| bitops.c | ||
| cmpdi2.c | ||
| csum_partial.S | ||
| delay.c | ||
| dump_tlb.c | ||
| iomap-pci.c | ||
| iomap.c | ||
| libgcc.h | ||
| lshrdi3.c | ||
| Makefile | ||
| memcpy.S | ||
| memset.S | ||
| mips-atomic.c | ||
| r3k_dump_tlb.c | ||
| strlen_user.S | ||
| strncpy_user.S | ||
| strnlen_user.S | ||
| ucmpdi2.c | ||
| uncached.c | ||