perf/x86: Make dummy_iregs static

Having pt_regs on-stack is unfortunate, it's 168 bytes. Since it isn't
actually used, make it a static variable. This both gets if off the
stack and ensures it gets 0 initialized, just in case someone does
look at it.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20201030151955.324273677@infradead.org

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 276b29d..b47cc42 100644 (file)
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -1738,7 +1738,7 @@ __intel_pmu_pebs_event(struct perf_event *event,
        struct x86_perf_regs perf_regs;
        struct pt_regs *regs = &perf_regs.regs;
        void *at = get_next_pebs_record_by_bit(base, top, bit);
-       struct pt_regs dummy_iregs;
+       static struct pt_regs dummy_iregs;
 
        if (hwc->flags & PERF_X86_EVENT_AUTO_RELOAD) {
                /*