From 9bcec938aab22a1b7ced916a6895e5029d4ed04f Mon Sep 17 00:00:00 2001 From: "Frank Ch. Eigler" Date: Tue, 25 Mar 2014 13:08:30 +0100 Subject: trace: add workaround for SystemTap PR13296 SystemTap sdt.h sometimes results in compiled probes without sufficient information to extract arguments. This can be solved in a slightly hacky way by encouraging the compiler to place arguments into registers. This patch fixes the apic_reset_irq_delivered() trace event on Fedora 20 with gcc-4.8.2-7.fc20 and systemtap-sdt-devel-2.4-2.fc20 on x86_64. Signed-off-by: Frank Ch. Eigler Signed-off-by: Stefan Hajnoczi --- hw/intc/apic_common.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'hw/intc') diff --git a/hw/intc/apic_common.c b/hw/intc/apic_common.c index c623fcc6d8..7ecce2dcce 100644 --- a/hw/intc/apic_common.c +++ b/hw/intc/apic_common.c @@ -117,7 +117,12 @@ void apic_report_irq_delivered(int delivered) void apic_reset_irq_delivered(void) { - trace_apic_reset_irq_delivered(apic_irq_delivered); + /* Copy this into a local variable to encourage gcc to emit a plain + * register for a sys/sdt.h marker. For details on this workaround, see: + * https://sourceware.org/bugzilla/show_bug.cgi?id=13296 + */ + volatile int a_i_d = apic_irq_delivered; + trace_apic_reset_irq_delivered(a_i_d); apic_irq_delivered = 0; } -- cgit v1.2.3