From 9bf670e5d364c43c7d918645533912e03676c17e Mon Sep 17 00:00:00 2001 From: Matt Evans Date: Thu, 12 Aug 2010 20:58:28 +0000 Subject: powerpc: Initialise paca->kstack before early_setup_secondary commit f761622e59433130bc33ad086ce219feee9eb961 upstream. As early setup calls down to slb_initialize(), we must have kstack initialised before checking "should we add a bolted SLB entry for our kstack?" Failing to do so means stack access requires an SLB miss exception to refill an entry dynamically, if the stack isn't accessible via SLB(0) (kernel text & static data). It's not always allowable to take such a miss, and intermittent crashes will result. Primary CPUs don't have this issue; an SLB entry is not bolted for their stack anyway (as that lives within SLB(0)). This patch therefore only affects the init of secondaries. Signed-off-by: Matt Evans Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Greg Kroah-Hartman --- arch/powerpc/kernel/head_64.S | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index cc8fb474d52..b92c4b07707 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -1479,9 +1479,6 @@ __secondary_start: /* Load TOC */ ld r2,PACATOC(r13) - /* Do early setup for that CPU (stab, slb, hash table pointer) */ - bl .early_setup_secondary - /* Initialize the kernel stack. Just a repeat for iSeries. */ LOAD_REG_ADDR(r3, current_set) sldi r28,r24,3 /* get current_set[cpu#] */ @@ -1489,6 +1486,9 @@ __secondary_start: addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD std r1,PACAKSAVE(r13) + /* Do early setup for that CPU (stab, slb, hash table pointer) */ + bl .early_setup_secondary + /* Clear backchain so we get nice backtraces */ li r7,0 mtlr r7 -- cgit v1.2.3-18-g5258