From f752ac4d7d96159776b0eea47489796bd90856fd Mon Sep 17 00:00:00 2001 From: Martin Schwidefsky Date: Tue, 16 Apr 2013 13:25:06 +0200 Subject: [PATCH] s390/mm: protection exception PSW for aborted transaction Protection exception usually are suppressing and the fault handler needs to rewind the PSW by the instruction length to get the correct fault address. Except for protection exceptions while the CPU is in the middle of a transaction. The CPU stores the transaction abort PSW at the start of the transaction, if the transaction is aborted the PSW is already correct and may not be modified by the fault handler. Signed-off-by: Martin Schwidefsky --- arch/s390/mm/fault.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c index 2fb9e63b8fc4..047c3e4c59a2 100644 --- a/arch/s390/mm/fault.c +++ b/arch/s390/mm/fault.c @@ -395,8 +395,13 @@ void __kprobes do_protection_exception(struct pt_regs *regs) int fault; trans_exc_code = regs->int_parm_long; - /* Protection exception is suppressing, decrement psw address. */ - regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16); + /* + * Protection exceptions are suppressing, decrement psw address. + * The exception to this rule are aborted transactions, for these + * the PSW already points to the correct location. + */ + if (!(regs->int_code & 0x200)) + regs->psw.addr = __rewind_psw(regs->psw, regs->int_code >> 16); /* * Check for low-address protection. This needs to be treated * as a special case because the translation exception code