From 50bec4ce5d36ebf96189dcc54e20c7fce4bf61bf Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Fri, 14 Nov 2008 18:18:05 +0100 Subject: [S390] ftrace: fix kernel stack backchain walking With CONFIG_IRQSOFF_TRACER the trace_hardirqs_off() function includes a call to __builtin_return_address(1). But we calltrace_hardirqs_off() from early entry code. There we have just a single stack frame. So this results in a kernel stack backchain walk that would walk beyond the kernel stack. Following the NULL terminated backchain this results in a lowcore read access. To fix this we simply call trace_hardirqs_off_caller() and pass the current instruction pointer. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/entry64.S | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) (limited to 'arch/s390/kernel/entry64.S') diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S index d7ce150453f2..41aca06682aa 100644 --- a/arch/s390/kernel/entry64.S +++ b/arch/s390/kernel/entry64.S @@ -61,19 +61,22 @@ _TIF_WORK_INT = (_TIF_SIGPENDING | _TIF_NOTIFY_RESUME | _TIF_NEED_RESCHED | \ #ifdef CONFIG_TRACE_IRQFLAGS .macro TRACE_IRQS_ON - brasl %r14,trace_hardirqs_on + basr %r2,%r0 + brasl %r14,trace_hardirqs_on_caller .endm .macro TRACE_IRQS_OFF - brasl %r14,trace_hardirqs_off + basr %r2,%r0 + brasl %r14,trace_hardirqs_off_caller .endm .macro TRACE_IRQS_CHECK + basr %r2,%r0 tm SP_PSW(%r15),0x03 # irqs enabled? jz 0f - brasl %r14,trace_hardirqs_on + brasl %r14,trace_hardirqs_on_caller j 1f -0: brasl %r14,trace_hardirqs_off +0: brasl %r14,trace_hardirqs_off_caller 1: .endm #else -- cgit v1.2.1