From 1f8cbb9c8365061d8b866e9b4f4403e029d57989 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 9 Feb 2016 12:00:16 +0100 Subject: [PATCH] s390/perf_event: fix address range for asynchronous stack git commit dc7ee00d4771 ("s390: lowcore stack pointer offsets") introduced a regression in regard to perf_callchain_kernel(). The stack pointer for the asynchronous stack in the lowcore now has an additional offset applied. This offset needs to be taken into account in the calculation for the low and high address for the stack. This bug was already partially fixed with 9cc5c206d9b4 ("s390/dumpstack: fix address ranges for asynchronous and panic stack"). This patch fixes it also for the perf_event code. Fixes: dc7ee00d4771 ("s390: lowcore stack pointer offsets") Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/perf_event.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/s390/kernel/perf_event.c b/arch/s390/kernel/perf_event.c index cfcba2dd9bb5..0943b11a2f6e 100644 --- a/arch/s390/kernel/perf_event.c +++ b/arch/s390/kernel/perf_event.c @@ -260,12 +260,13 @@ static unsigned long __store_trace(struct perf_callchain_entry *entry, void perf_callchain_kernel(struct perf_callchain_entry *entry, struct pt_regs *regs) { - unsigned long head; + unsigned long head, frame_size; struct stack_frame *head_sf; if (user_mode(regs)) return; + frame_size = STACK_FRAME_OVERHEAD + sizeof(struct pt_regs); head = regs->gprs[15]; head_sf = (struct stack_frame *) head; @@ -273,8 +274,9 @@ void perf_callchain_kernel(struct perf_callchain_entry *entry, return; head = head_sf->back_chain; - head = __store_trace(entry, head, S390_lowcore.async_stack - ASYNC_SIZE, - S390_lowcore.async_stack); + head = __store_trace(entry, head, + S390_lowcore.async_stack + frame_size - ASYNC_SIZE, + S390_lowcore.async_stack + frame_size); __store_trace(entry, head, S390_lowcore.thread_info, S390_lowcore.thread_info + THREAD_SIZE); -- 2.20.1