Safe memory functions

Introduce *x() wrappers for strdup(), malloc(), and calloc() which abort
on ENOMEM.

Fixes `-Wanalyzer-possible-null-dereference` warnings.

meson.build

@@ -86,6 +86,7 @@ endif
 preload_lib = shared_library('umockdev-preload',
   ['src/libumockdev-preload.c',
    'src/debug.c',
+   'src/utils.c',
    'src/ioctl_tree.c'],
   c_args: ['-fvisibility=default'],
   version: '0.0.0',
@@ -111,6 +112,7 @@ umockdev_lib = shared_library('umockdev',
    'src/uevent_sender.c',
    'src/ioctl_tree.vapi',
    'src/ioctl_tree.c',
+   'src/utils.c',
    'src/debug.c'],
   vala_vapi: 'umockdev-1.0.vapi',
   vala_gir: 'UMockdev-1.0.gir',
@@ -172,6 +174,7 @@ umockdev_record_exe = executable('umockdev-record',
    'src/umockdev-spi.vala',
    'src/ioctl_tree.vapi',
    'src/ioctl_tree.c',
+   'src/utils.c',
    'src/debug.c'],
   dependencies: [glib, gobject, gio_unix, vapi_posix, vapi_config, vapi_ioctl, libpcap],
   link_with: [umockdev_utils_lib],
@@ -238,6 +241,7 @@ endif
 test('ioctl-tree', executable('test-ioctl-tree',
   ['tests/test-ioctl-tree.c',
    'src/ioctl_tree.c',
+   'src/utils.c',
    'src/debug.c'],
   include_directories: include_directories('src'),
   dependencies: [glib]))

src/debug.c

@@ -3,6 +3,7 @@
 #include <stdio.h>
 
 #include "debug.h"
+#include "utils.h"
 
 unsigned debug_categories = 0;
 
@@ -13,7 +14,7 @@ init_debug(void)
     char *d_copy, *token;
     if (d == NULL)
 	return;
-    d_copy = strdup(d);
+    d_copy = strdupx(d);
     for (token = strtok(d_copy, " ,"); token; token = strtok(NULL, " ,")) {
 	if (strcmp (token, "all") == 0)
 	    debug_categories = ~0;

src/ioctl_tree.c

@@ -27,23 +27,14 @@
 #include <linux/hidraw.h>
 
 #include "debug.h"
+#include "utils.h"
 #include "ioctl_tree.h"
 
 #define TRUE 1
 #define FALSE 0
 
 #define UNUSED __attribute__ ((unused))
 
-static void *
-callocx (size_t nmemb, size_t size)
-{
-  void *r = calloc (nmemb, size);
-  if (r == NULL) {
-      perror ("failed to allocate memory");
-      abort ();
-  }
-  return r;
-}
 
 /***********************************
  *
@@ -328,7 +319,7 @@ ioctl_node_list *
 ioctl_node_list_new(void)
 {
     ioctl_node_list *l;
-    l = malloc(sizeof(ioctl_node_list));
+    l = mallocx(sizeof(ioctl_node_list));
     l->n = 0;
     l->capacity = 10;
     l->items = callocx(sizeof(ioctl_tree *), l->capacity);
@@ -496,7 +487,7 @@ static void
 ioctl_simplestruct_init_from_bin(ioctl_tree * node, const void *data)
 {
     DBG(DBG_IOCTL_TREE, "ioctl_simplestruct_init_from_bin: %s(%X): size is %u bytes\n", node->type->name, (unsigned) node->id, (unsigned) NSIZE(node));
-    node->data = malloc(NSIZE(node));
+    node->data = mallocx(NSIZE(node));
     memcpy(node->data, data, NSIZE(node));
 }
 
@@ -507,7 +498,7 @@ ioctl_simplestruct_init_from_text(ioctl_tree * node, const char *data)
      * correct length for data; this happens for variable length ioctls such as
      * EVIOCGBIT */
     size_t data_len = strlen(data) / 2;
-    node->data = malloc(data_len);
+    node->data = mallocx(data_len);
 
     if (NSIZE(node) != data_len) {
 	DBG(DBG_IOCTL_TREE, "ioctl_simplestruct_init_from_text: adjusting ioctl ID %X (size %u) to actual data length %zu\n",
@@ -570,7 +561,7 @@ ioctl_varlenstruct_init_from_bin(ioctl_tree * node, const void *data)
 {
     size_t size = node->type->get_data_size(node->id, data);
     DBG(DBG_IOCTL_TREE, "ioctl_varlenstruct_init_from_bin: %s(%X): size is %zu bytes\n", node->type->name, (unsigned) node->id, size);
-    node->data = malloc(size);
+    node->data = mallocx(size);
     memcpy(node->data, data, size);
 }
 
@@ -579,7 +570,7 @@ ioctl_varlenstruct_init_from_text(ioctl_tree * node, const char *data)
 {
     size_t data_len = strlen(data) / 2;
 
-    node->data = malloc(data_len);
+    node->data = mallocx(data_len);
 
     if (!read_hex(data, node->data, data_len)) {
 	fprintf(stderr, "ioctl_varlenstruct_init_from_text: failed to parse '%s'\n", data);
@@ -999,7 +990,7 @@ ioctl_type_get_by_name(const char *name, IOCTL_REQUEST_TYPE *out_id)
     long offset = 0;
 
     /* chop off real name from offset */
-    real_name = strdup(name);
+    real_name = strdupx(name);
     parens = strchr(real_name, '(');
     if (parens != NULL) {
 	*parens = '\0';

src/libumockdev-preload.c

@@ -57,6 +57,7 @@
 
 #include "config.h"
 #include "debug.h"
+#include "utils.h"
 #include "ioctl_tree.h"
 
 /* fix missing O_TMPFILE on some systems */
@@ -483,9 +484,9 @@ ioctl_emulate_open(int fd, const char *dev_path, int must_exist)
 	}
     }
 
-    fdinfo = malloc(sizeof(struct ioctl_fd_info));
+    fdinfo = mallocx(sizeof(struct ioctl_fd_info));
     fdinfo->ioctl_sock = sock;
-    fdinfo->dev_path = strdup(dev_path);
+    fdinfo->dev_path = strdupx(dev_path);
     fdinfo->is_default = is_default;
     pthread_mutex_init(&fdinfo->sock_lock, NULL);
 
@@ -856,7 +857,7 @@ script_start_record(int fd, const char *logname, const char *recording_path, enu
 	}
     }
 
-    srinfo = malloc(sizeof(struct script_record_info));
+    srinfo = mallocx(sizeof(struct script_record_info));
     srinfo->log = log;
     if (clock_gettime(CLOCK_MONOTONIC, &srinfo->time) < 0) {
 	fprintf(stderr, "libumockdev-preload: failed to clock_gettime: %m\n");

src/uevent_sender.c

@@ -30,6 +30,7 @@
 
 #include <libudev.h>
 
+#include "utils.h"
 #include "uevent_sender.h"
 
 struct _uevent_sender {
@@ -49,7 +50,7 @@ uevent_sender_open(const char *rootpath)
 	perror("uevent_sender_open: cannot allocate struct");
 	abort();
     }
-    s->rootpath = strdup(rootpath);
+    s->rootpath = strdupx(rootpath);
     s->udev = udev_new();
     snprintf(s->socket_glob, sizeof(s->socket_glob), "%s/event[0-9]*", rootpath);
 

src/utils.c

@@ -0,0 +1,40 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "utils.h"
+
+static void
+abort_errno (const char *msg)
+{
+  perror (msg);
+  abort ();
+}
+
+void *
+callocx (size_t nmemb, size_t size)
+{
+  void *r = calloc (nmemb, size);
+  if (r == NULL)
+      abort_errno ("failed to allocate memory");
+  return r;
+}
+
+void *
+mallocx (size_t size)
+{
+  void *r = malloc (size);
+  if (r == NULL)
+      abort_errno ("failed to allocate memory");
+  return r;
+}
+
+
+char *
+strdupx (const char *s)
+{
+  char *r = strdup (s);
+  if (r == NULL)
+    abort_errno ("failed to allocate memory for strdup");
+  return r;
+}

src/utils.h

@@ -0,0 +1,6 @@
+#pragma once
+
+/* variants of glibc functions that abort() on ENOMEM */
+void *mallocx (size_t size);
+void *callocx (size_t nmemb, size_t size);
+char *strdupx (const char *s);