Commit 8b55992f added some Coverity comments to silence what was
a real bug in the code. Since then, we've had a miserable run
of trying to fix the underlying problem (commits c059cde and
ba5193c), and still have a problem on 32-bit machines.
This fixes the problem for once and for all, by realizing that
on older xen, cpumap_t is identical to uint64_t, and using the
new virendian.h to do the transformation from the API (documented
to be little-endian) to the host structure.
* src/xen/xen_hypervisor.c (virXen_setvcpumap): Do the conversion
correctly. Finally.
---
src/xen/xen_hypervisor.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
diff --git a/src/xen/xen_hypervisor.c b/src/xen/xen_hypervisor.c
index 9b7dd2e..d803972 100644
--- a/src/xen/xen_hypervisor.c
+++ b/src/xen/xen_hypervisor.c
@@ -80,6 +80,7 @@
#include "virfile.h"
#include "virnodesuspend.h"
#include "virtypedparam.h"
+#include "virendian.h"
#define VIR_FROM_THIS VIR_FROM_XEN
@@ -1773,18 +1774,13 @@ virXen_setvcpumap(int handle,
ret = -1;
} else {
cpumap_t xen_cpumap; /* limited to 64 CPUs in old hypervisors */
- uint64_t *pm = &xen_cpumap;
- int j;
+ char buf[8] = "";
- if ((maplen > (int)sizeof(cpumap_t)) || (sizeof(cpumap_t) & 7))
+ if (maplen > sizeof(cpumap_t) || sizeof(cpumap_t) != sizeof(uint64_t))
return -1;
-
- memset(&xen_cpumap, 0, sizeof(cpumap_t));
- for (j = 0; j < maplen; j++) {
- if ((j & 7) == 0)
- pm = (uint64_t *)((uint64_t)&xen_cpumap + (j & ~0x7UL));
- *pm |= (uint64_t)cpumap[j] << (8 * (j & 7));
- }
+ /* Supply trailing 0s if user's input array was short */
+ memcpy(buf, cpumap, maplen);
+ xen_cpumap = virReadBufInt64LE(buf);
if (hv_versions.hypervisor == 1) {
xen_op_v1 op;
--
1.8.1.2
--
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