From 922b9f86a020258d3ea3bfed27251efaed7a03a3 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Mon, 20 Feb 2012 21:32:30 +0000 Subject: [PATCH] powerpc: Fix program check handling when lockdep is enabled In commit 54321242afe ("Disable interrupts early in Program Check"), we switched from enabling to disabling interrupts in program_check_common. Whereas ENABLE_INTS leaves r3 untouched, if lockdep is enabled DISABLE_INTS calls into lockdep code and will clobber r3. That means we pass a bogus struct pt_regs* into program_check_exception() and all hell breaks loose. So load our regs pointer into r3 after we call DISABLE_INTS. Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/kernel/exceptions-64s.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 3844ca7c5099..15c5a4f6de01 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -774,8 +774,8 @@ alignment_common: program_check_common: EXCEPTION_PROLOG_COMMON(0x700, PACA_EXGEN) bl .save_nvgprs - addi r3,r1,STACK_FRAME_OVERHEAD DISABLE_INTS + addi r3,r1,STACK_FRAME_OVERHEAD bl .program_check_exception b .ret_from_except