[4.4,3/9] arm64: fix for bad_mode() handler to always result in panic

Message ID 20191122105113.11213-3-lee.jones@linaro.org
State Superseded
Headers show
Series
  • [4.4,1/9] ARM: 8904/1: skip nomap memblocks while finding the lowmem/highmem boundary
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Commit Message

Lee Jones Nov. 22, 2019, 10:51 a.m.
From: Hari Vyas <hari.vyas@broadcom.com>


[ Upstream commit e4ba15debcfd27f60d43da940a58108783bff2a6 ]

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>

---
 arch/arm64/kernel/traps.c | 1 -
 1 file changed, 1 deletion(-)

-- 
2.24.0

Patch

diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 6b4579e07aa2..02710f99c137 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -448,7 +448,6 @@  asmlinkage void bad_mode(struct pt_regs *regs, int reason, unsigned int esr)
 	pr_crit("Bad mode in %s handler detected, code 0x%08x -- %s\n",
 		handler[reason], esr, esr_get_class_string(esr));
 
-	die("Oops - bad mode", regs, 0);
 	local_irq_disable();
 	panic("bad mode");
 }