Re: [libvirt] [PATCH 11/11] hypervisor: Revisit Coverity issues regarding cpumap

Turns out the issue regarding ptr_arith and sign_exension weren't false positives. When shifting an 'unsigned char' as a target, it gets promoted to an 'int'; however, that 'int' cannot be shifted 32 bits which was how the algorithm was written. For the ptr_arith rather than index into the cpumap, change the to address as necessary and assign directly. --- src/xen/xen_hypervisor.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/xen/xen_hypervisor.c b/src/xen/xen_hypervisor.c index 186f0c7..3ea70a2 100644 --- a/src/xen/xen_hypervisor.c +++ b/src/xen/xen_hypervisor.c @@ -1766,17 +1766,17 @@ virXen_setvcpumap(int handle, int id, unsigned int vcpu, ret = -1; } else { cpumap_t xen_cpumap; /* limited to 64 CPUs in old hypervisors */ - uint64_t *pm = &xen_cpumap; + uint64_t *pm; int j; if ((maplen > (int)sizeof(cpumap_t)) || (sizeof(cpumap_t) & 7)) return -1; - memset(pm, 0, sizeof(cpumap_t)); + memset(&xen_cpumap, 0, sizeof(cpumap_t)); for (j = 0; j < maplen; j++) { - /* coverity[ptr_arith] */ - /* coverity[sign_extension] */ - *(pm + (j / 8)) |= cpumap[j] << (8 * (j & 7)); + if ((j & 7) == 0) + pm = (uint64_t *)((uint64_t)&xen_cpumap + (j & ~0x7UL)); + *pm |= (uint64_t)cpumap[j] << (8 * (j & 7)); } if (hv_versions.hypervisor == 1) {