xentrace: reduce size of extradata in trace_irq_mask()

Reduce size of extra_data in to avoid possible crash in trace_var.

(XEN) Assertion 'extra_word <= TRACE_EXTRA_MAX' failed at trace.c:687
(XEN) Xen call trace:
(XEN)    [<ffff82c480128783>] __trace_var+0x4d/0x3b8
(XEN)    [<ffff82c480162172>] trace_irq_mask+0x49/0x4b
(XEN)    [<ffff82c4801631ae>] __assign_irq_vector+0x241/0x374
(XEN)    [<ffff82c48015d813>] set_desc_affinity+0x5d/0xd4
(XEN)    [<ffff82c480160708>] set_msi_affinity+0x44/0x1c1
(XEN)    [<ffff82c480162938>] move_masked_irq+0x9c/0xcd
(XEN)    [<ffff82c4801629a7>] move_native_irq+0x3e/0x53
(XEN)    [<ffff82c48015d969>] ack_msi_irq+0x2c/0x6e
(XEN)    [<ffff82c4801622e3>] do_IRQ+0x16f/0x66d

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Acked-by: George Dunlap <george.dunlap@eu.citrix.com>

diff --git a/xen/arch/x86/irq.c b/xen/arch/x86/irq.c
index c89a3c43c272fde080fcacb05333770f4b0c2296..7c5a8b64048430e98891fb7b9daaca31b1161751 100644 (file)
--- a/xen/arch/x86/irq.c
+++ b/xen/arch/x86/irq.c
@@ -77,10 +77,14 @@ void unlock_vector_lock(void)
 static void trace_irq_mask(u32 event, int irq, int vector, cpumask_t *mask)
 {
     struct {
-        int irq, vec;
-        cpumask_t mask;
-    } d = { irq, vector, *mask };
-    trace_var(event, 1, sizeof(d), (unsigned char *)&d);
+        unsigned int irq:16, vec:16;
+        unsigned int mask[6];
+    } d;
+    d.irq = irq;
+    d.vec = vector;
+    memset(d.mask, 0, sizeof(d.mask));
+    memcpy(d.mask, mask, min(sizeof(d.mask), sizeof(cpumask_t)));
+    trace_var(event, 1, sizeof(d), &d);
 }
 
 static int __init __bind_irq_vector(int irq, int vector, cpumask_t cpu_mask)