libkmod-module: check for NULL before accessing pointers

This introduces a few missing NULL-checks in public functions, and
align their docstrings with real behavior by getting rid of copy-paste
mistakes.

Signed-off-by: Luca Bruno <luca.bruno@coreos.com>

diff --git a/TODO b/TODO
index 537e7e13752f48695b07ccceb4512ad5c7e8fcee..3fe06ebe17346f9501819490812b4c132403b47b 100644 (file)
--- a/TODO
+++ b/TODO
@@ -35,6 +35,11 @@ and libkmod
    - kmod_module_symbols_free_list()
    - kmod_module_dependency_symbols_free_list()
 
+* libkmod API breaking changes:
+   - dedicated error value for all kmod_*_get_crc() functions. Currently there
+     is no way for callers to distinguish between a valid CRC=0 and the error
+     code 0.
+
 * index: drop the "open(), seek(), read()" implementation and use another one
   with mmap(). When lookup() is called and the file is not mmaped, mmap it.
   Another possibility is to drop the mmap implementation relying on VFS to have

diff --git a/libkmod/libkmod-module.c b/libkmod/libkmod-module.c
index 0a3ef11c860fb180d4188257c6965d7c2a8ce259..ee420f4ec2bf5a32b8f69163d645ed2f24dda381 100644 (file)
--- a/libkmod/libkmod-module.c
+++ b/libkmod/libkmod-module.c
@@ -2519,7 +2519,7 @@ KMOD_EXPORT const char *kmod_module_version_get_symbol(const struct kmod_list *e
 {
        struct kmod_module_version *version;
 
-       if (entry == NULL)
+       if (entry == NULL || entry->data == NULL)
                return NULL;
 
        version = entry->data;
@@ -2532,14 +2532,13 @@ KMOD_EXPORT const char *kmod_module_version_get_symbol(const struct kmod_list *e
  *
  * Get the crc of a kmod module version.
  *
- * Returns: the crc of this kmod module version on success or NULL on
- * failure. The string is owned by the version, do not free it.
+ * Returns: the crc of this kmod module version if available, otherwise default to 0.
  */
 KMOD_EXPORT uint64_t kmod_module_version_get_crc(const struct kmod_list *entry)
 {
        struct kmod_module_version *version;
 
-       if (entry == NULL)
+       if (entry == NULL || entry->data == NULL)
                return 0;
 
        version = entry->data;
@@ -2660,7 +2659,7 @@ KMOD_EXPORT const char *kmod_module_symbol_get_symbol(const struct kmod_list *en
 {
        struct kmod_module_symbol *symbol;
 
-       if (entry == NULL)
+       if (entry == NULL || entry->data == NULL)
                return NULL;
 
        symbol = entry->data;
@@ -2673,14 +2672,13 @@ KMOD_EXPORT const char *kmod_module_symbol_get_symbol(const struct kmod_list *en
  *
  * Get the crc of a kmod module symbol.
  *
- * Returns: the crc of this kmod module symbol on success or NULL on
- * failure. The string is owned by the symbol, do not free it.
+ * Returns: the crc of this kmod module symbol if available, otherwise default to 0.
  */
 KMOD_EXPORT uint64_t kmod_module_symbol_get_crc(const struct kmod_list *entry)
 {
        struct kmod_module_symbol *symbol;
 
-       if (entry == NULL)
+       if (entry == NULL || entry->data == NULL)
                return 0;
 
        symbol = entry->data;
@@ -2806,7 +2804,7 @@ KMOD_EXPORT const char *kmod_module_dependency_symbol_get_symbol(const struct km
 {
        struct kmod_module_dependency_symbol *dependency_symbol;
 
-       if (entry == NULL)
+       if (entry == NULL || entry->data == NULL)
                return NULL;
 
        dependency_symbol = entry->data;
@@ -2819,14 +2817,13 @@ KMOD_EXPORT const char *kmod_module_dependency_symbol_get_symbol(const struct km
  *
  * Get the crc of a kmod module dependency_symbol.
  *
- * Returns: the crc of this kmod module dependency_symbol on success or NULL on
- * failure. The string is owned by the dependency_symbol, do not free it.
+ * Returns: the crc of this kmod module dependency_symbol if available, otherwise default to 0.
  */
 KMOD_EXPORT uint64_t kmod_module_dependency_symbol_get_crc(const struct kmod_list *entry)
 {
        struct kmod_module_dependency_symbol *dependency_symbol;
 
-       if (entry == NULL)
+       if (entry == NULL || entry->data == NULL)
                return 0;
 
        dependency_symbol = entry->data;
@@ -2846,7 +2843,7 @@ KMOD_EXPORT int kmod_module_dependency_symbol_get_bind(const struct kmod_list *e
 {
        struct kmod_module_dependency_symbol *dependency_symbol;
 
-       if (entry == NULL)
+       if (entry == NULL || entry->data == NULL)
                return 0;
 
        dependency_symbol = entry->data;