Kernel threads should be able to use COP2 if the platform needs it.
Do not call die_if_kernel() for a coprocessor unusable exception if
the exception due to COP2 usage. Instead, the default notifier for
COP2 exceptions is updated to call die_if_kernel.
Signed-off-by: Jayachandran C <jchandra@xxxxxxxxxxxx>
---
arch/mips/kernel/traps.c | 15 +++++----------
1 file changed, 5 insertions(+), 10 deletions(-)
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index a200b5b..36c242f 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -970,15 +970,9 @@ static int default_cu2_call(struct notifier_block *nfb, unsigned long action,
{
struct pt_regs *regs = data;
- switch (action) {
- default:
- die_if_kernel("Unhandled kernel unaligned access or invalid "
+ die_if_kernel("COP2: Unhandled kernel unaligned access or invalid "
"instruction", regs);
- /* Fall through */
-
- case CU2_EXCEPTION:
- force_sig(SIGILL, current);
- }
+ force_sig(SIGILL, current);
return NOTIFY_OK;
}
@@ -992,10 +986,11 @@ asmlinkage void do_cpu(struct pt_regs *regs)
int status;
unsigned long __maybe_unused flags;
- die_if_kernel("do_cpu invoked from kernel context!", regs);
-
cpid = (regs->cp0_cause >> CAUSEB_CE) & 3;
+ if (cpid != 2)
+ die_if_kernel("do_cpu invoked from kernel context!", regs);
+
switch (cpid) {
case 0:
epc = (unsigned int __user *)exception_epc(regs);
--
1.7.9.5
