[PATCH] x86/xen: Improve failed hypercall debugging

From: Andy Lutomirski
Date: Tue May 02 2017 - 13:59:41 EST


When fiddling with xen_exit_mmap(), I noticed that failed multicall
debugging doesn't work if the multicall is just one call. Fix it.

Cc: Juergen Gross <jgross@xxxxxxxx>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxx>
---
arch/x86/xen/multicalls.c | 26 +++++++++++++-------------
1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c
index ea54a08d8301..b6b3f024d342 100644
--- a/arch/x86/xen/multicalls.c
+++ b/arch/x86/xen/multicalls.c
@@ -96,23 +96,23 @@ void xen_mc_flush(void)
for (i = 0; i < b->mcidx; i++)
if (b->entries[i].result < 0)
ret++;
+ }

#if MC_DEBUG
- if (ret) {
- printk(KERN_ERR "%d multicall(s) failed: cpu %d\n",
- ret, smp_processor_id());
- dump_stack();
- for (i = 0; i < b->mcidx; i++) {
- printk(KERN_DEBUG " call %2d/%d: op=%lu arg=[%lx] result=%ld\t%pF\n",
- i+1, b->mcidx,
- b->debug[i].op,
- b->debug[i].args[0],
- b->entries[i].result,
- b->caller[i]);
- }
+ if (ret) {
+ printk(KERN_ERR "%d multicall(s) failed: cpu %d\n",
+ ret, smp_processor_id());
+ dump_stack();
+ for (i = 0; i < b->mcidx; i++) {
+ printk(KERN_DEBUG " call %2d/%d: op=%lu arg=[%lx] result=%ld\t%pF\n",
+ i+1, b->mcidx,
+ b->debug[i].op,
+ b->debug[i].args[0],
+ b->entries[i].result,
+ b->caller[i]);
}
-#endif
}
+#endif

b->mcidx = 0;
b->argidx = 0;
--
2.9.3