Commit e1d12d70 authored Feb 18, 2015 by Heiko Carstens Committed by Martin Schwidefsky Mar 25, 2015

s390/traps: panic() instead of die() on translation exception



In case of a translation exception the page tables are corrupted. If the
exception handler then calls die() which again calls show_regs()
-> show_code() -> copy_from_user(), the kernel may access the same memory
location again and generates yet another translation exception. Which in turn
will lead to a deadlock on the die_lock spinlock, which the kernel tries to
grab recursively.

Given that the page tables are corrupted anyway, if we see such an exception,
let's simply panic.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

parent 86cd741b

arch/s390/kernel/traps.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -174,7 +174,7 @@ static inline void do_fp_trap(struct pt_regs *regs, int fpc)
		void translation_exception(struct pt_regs *regs)
		{
		/* May never happen. */
		die(regs, "Translation exception");
		panic("Translation exception");
		}

		void illegal_op(struct pt_regs *regs)

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