spapr_pci: Fix leak in spapr_phb_vfio_get_loc_code() with g_autofree

This uses g_autofree to simplify logic in spapr_phb_vfio_get_loc_code(),
in the process fixing a leak in one of the paths.  I'm told this fixes
Coverity error CID 1460454

Reported-by: Peter Maydell <peter.maydell@linaro.org>
Fixes: 16b0ea1d852 ("spapr_pci: populate ibm,loc-code")
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

diff --git a/hw/ppc/spapr_pci.c b/hw/ppc/spapr_pci.c
index 7a725855f91fa9ce4a9d12fcfc2720f183179219..7430bd63142b2efae67cf831add322c65bfefe96 100644 (file)
--- a/hw/ppc/spapr_pci.c
+++ b/hw/ppc/spapr_pci.c
@@ -782,33 +782,29 @@ static AddressSpace *spapr_pci_dma_iommu(PCIBus *bus, void *opaque, int devfn)
 
 static char *spapr_phb_vfio_get_loc_code(SpaprPhbState *sphb,  PCIDevice *pdev)
 {
-    char *path = NULL, *buf = NULL, *host = NULL;
+    g_autofree char *path = NULL;
+    g_autofree char *host = NULL;
+    g_autofree char *devspec = NULL;
+    char *buf = NULL;
 
     /* Get the PCI VFIO host id */
     host = object_property_get_str(OBJECT(pdev), "host", NULL);
     if (!host) {
-        goto err_out;
+        return NULL;
     }
 
     /* Construct the path of the file that will give us the DT location */
     path = g_strdup_printf("/sys/bus/pci/devices/%s/devspec", host);
-    g_free(host);
-    if (!g_file_get_contents(path, &buf, NULL, NULL)) {
-        goto err_out;
+    if (!g_file_get_contents(path, &devspec, NULL, NULL)) {
+        return NULL;
     }
-    g_free(path);
 
     /* Construct and read from host device tree the loc-code */
-    path = g_strdup_printf("/proc/device-tree%s/ibm,loc-code", buf);
-    g_free(buf);
+    path = g_strdup_printf("/proc/device-tree%s/ibm,loc-code", devspec);
     if (!g_file_get_contents(path, &buf, NULL, NULL)) {
-        goto err_out;
+        return NULL;
     }
     return buf;
-
-err_out:
-    g_free(path);
-    return NULL;
 }
 
 static char *spapr_phb_get_loc_code(SpaprPhbState *sphb, PCIDevice *pdev)