fix coverity warnings (#611)

Fix a few coverity-identified issues.

Signed-off-by: John Levon <john.levon@nutanix.com>
Reviewed-by: Swapnil Ingle <swapnil.ingle@nutanix.com>

2 files changed, 23 insertions, 15 deletions

diff --git a/samples/client.c b/samples/client.c
index 80a84d4..c492854 100644
--- a/samples/client.c
+++ b/samples/client.c
@@ -276,8 +276,8 @@ mmap_sparse_areas(int *fds, struct vfio_region_info *region_info,
 
         ssize_t ret;
         void *addr;
-        char pathname[BUFSIZ];
-        char buf[PATH_MAX];
+        char pathname[PATH_MAX];
+        char buf[PATH_MAX] = "";
 
         ret = snprintf(pathname, sizeof(pathname), "/proc/self/fd/%d", fds[i]);
         assert(ret != -1 && (size_t)ret < sizeof(pathname));
@@ -285,7 +285,6 @@ mmap_sparse_areas(int *fds, struct vfio_region_info *region_info,
         if (ret == -1) {
             err(EXIT_FAILURE, "failed to resolve file descriptor %d", fds[i]);
         }
-        buf[ret + 1] = '\0';
         addr = mmap(NULL, sparse->areas[i].size, PROT_READ | PROT_WRITE,
                     MAP_SHARED, fds[i], region_info->offset +
                     sparse->areas[i].offset);
@@ -295,6 +294,9 @@ mmap_sparse_areas(int *fds, struct vfio_region_info *region_info,
                 i, buf, sparse->areas[i].offset,
                 sparse->areas[i].offset + sparse->areas[i].size - 1);
         }
+
+        ret = munmap(addr, sparse->areas[i].size);
+        assert(ret == 0);
     }
 }
 
@@ -1080,12 +1082,13 @@ map_dma_regions(int sock, struct vfio_user_dma_map *dma_regions,
 
 int main(int argc, char *argv[])
 {
-	int ret, sock, irq_fd;
+    char template[] = "/tmp/libvfio-user.XXXXXX";
+    int ret, sock, irq_fd;
     struct vfio_user_dma_map *dma_regions;
     struct vfio_user_device_info client_dev_info = {0};
     int *dma_region_fds;
     int i;
-    FILE *fp;
+    int tmpfd;
     int server_max_fds;
     size_t server_max_data_xfer_size;
     size_t pgsize;
@@ -1159,14 +1162,16 @@ int main(int argc, char *argv[])
      */
     nr_dma_regions = server_max_fds << 1;
 
-    if ((fp = tmpfile()) == NULL) {
-        err(EXIT_FAILURE, "failed to create DMA file");
+    if ((tmpfd = mkstemp(template)) == -1) {
+        err(EXIT_FAILURE, "failed to create backing file");
     }
 
-    if ((ret = ftruncate(fileno(fp), nr_dma_regions * sysconf(_SC_PAGESIZE))) == -1) {
+    if ((ret = ftruncate(tmpfd, nr_dma_regions * sysconf(_SC_PAGESIZE))) == -1) {
         err(EXIT_FAILURE, "failed to truncate file");
     }
 
+    unlink(template);
+
     dma_regions = alloca(sizeof(*dma_regions) * nr_dma_regions);
     dma_region_fds = alloca(sizeof(*dma_region_fds) * nr_dma_regions);
 
@@ -1176,7 +1181,7 @@ int main(int argc, char *argv[])
         dma_regions[i].size = sysconf(_SC_PAGESIZE);
         dma_regions[i].offset = dma_regions[i].addr;
         dma_regions[i].flags = VFIO_USER_F_DMA_REGION_READ | VFIO_USER_F_DMA_REGION_WRITE;
-        dma_region_fds[i] = fileno(fp);
+        dma_region_fds[i] = tmpfd;
     }
 
     map_dma_regions(sock, dma_regions, dma_region_fds, nr_dma_regions);
diff --git a/samples/server.c b/samples/server.c
index 4da476b..416d5c8 100644
--- a/samples/server.c
+++ b/samples/server.c
@@ -418,6 +418,7 @@ page_align(size_t size)
 
 int main(int argc, char *argv[])
 {
+    char template[] = "/tmp/libvfio-user.XXXXXX";
     int ret;
     bool verbose = false;
     int opt;
@@ -430,7 +431,7 @@ int main(int argc, char *argv[])
         }
     };
     vfu_ctx_t *vfu_ctx;
-    FILE *fp;
+    int tmpfd;
     const vfu_migration_callbacks_t migr_callbacks = {
         .version = VFU_MIGR_CALLBACKS_VERS,
         .transition = &migration_device_state_transition,
@@ -494,10 +495,12 @@ int main(int argc, char *argv[])
      * We choose to use a single file which contains both BAR1 and the migration
      * registers. They could also be completely different files.
      */
-    if ((fp = tmpfile()) == NULL) {
+    if ((tmpfd = mkstemp(template)) == -1) {
         err(EXIT_FAILURE, "failed to create backing file");
     }
 
+    unlink(template);
+
     server_data.bar1_size = bar1_size;
 
     /*
@@ -509,11 +512,11 @@ int main(int argc, char *argv[])
     migr_data_size = page_align(bar1_size + sizeof(time_t));
     migr_size = migr_regs_size + migr_data_size;
 
-    if (ftruncate(fileno(fp), server_data.bar1_size + migr_size) == -1) {
+    if (ftruncate(tmpfd, server_data.bar1_size + migr_size) == -1) {
         err(EXIT_FAILURE, "failed to truncate backing file");
     }
     server_data.bar1 = mmap(NULL, server_data.bar1_size, PROT_READ | PROT_WRITE,
-                            MAP_SHARED, fileno(fp), 0);
+                            MAP_SHARED, tmpfd, 0);
     if (server_data.bar1 == MAP_FAILED) {
         err(EXIT_FAILURE, "failed to mmap BAR1");
     }
@@ -524,7 +527,7 @@ int main(int argc, char *argv[])
     ret = vfu_setup_region(vfu_ctx, VFU_PCI_DEV_BAR1_REGION_IDX,
                            server_data.bar1_size, &bar1_access,
                            VFU_REGION_FLAG_RW, bar1_mmap_areas, 2,
-                           fileno(fp), 0);
+                           tmpfd, 0);
     if (ret < 0) {
         err(EXIT_FAILURE, "failed to setup BAR1 region");
     }
@@ -544,7 +547,7 @@ int main(int argc, char *argv[])
      */
     ret = vfu_setup_region(vfu_ctx, VFU_PCI_DEV_MIGR_REGION_IDX, migr_size,
                            NULL, VFU_REGION_FLAG_RW, migr_mmap_areas,
-                           ARRAY_SIZE(migr_mmap_areas), fileno(fp),
+                           ARRAY_SIZE(migr_mmap_areas), tmpfd,
                            server_data.bar1_size);
     if (ret < 0) {
         err(EXIT_FAILURE, "failed to setup migration region");