arm64: fix for bad_mode() handler to always result in panic

commit e4ba15debcfd27f60d43da940a58108783bff2a6 upstream.

The bad_mode() handler is called if we encounter an uunknown exception,
with the expectation that the subsequent call to panic() will halt the
system. Unfortunately, if the exception calling bad_mode() is taken from
EL0, then the call to die() can end up killing the current user task and
calling schedule() instead of falling through to panic().

Remove the die() call altogether, since we really want to bring down the
machine in this "impossible" case.

Signed-off-by: Hari Vyas <hari.vyas@broadcom.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index a4e49e947684dd1a51696cadd81f61fa73c68e6f..5ae9c86c30d1d92f248f5c096d05ce7c58ee3e6d 100644 (file)
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -648,7 +648,6 @@ asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
                handler[reason], smp_processor_id(), esr,
                esr_get_class_string(esr));
 
-       die("Oops - bad mode", regs, 0);
        local_irq_disable();
        panic("bad mode");
 }