inet: fix: possible unaligned access in packed structure (inet/inet6)

[lttng-tools.git] / src / common / macros.h

diff --git a/src/common/macros.h b/src/common/macros.h
index 9304388554d0af82e61ab6ae2e0abddca933960d..e2d0fcf3eae8e61fd1c7030e5f807e3d1b92bdf6 100644 (file)
--- a/src/common/macros.h
+++ b/src/common/macros.h
@@ -21,6 +21,7 @@
 
 #include <stdlib.h>
 #include <string.h>
+#include <common/compat/string.h>
 
 /*
  * Takes a pointer x and transform it so we can use it to access members
@@ -62,7 +63,7 @@ void *zmalloc(size_t len)
 #endif
 
 #ifndef max_t
-#define max_t(type, a, b)      ((type) max(a, b))
+#define max_t(type, a, b)      max((type) a, (type) b)
 #endif
 
 #ifndef min
@@ -73,10 +74,26 @@ void *zmalloc(size_t len)
 #define LTTNG_PACKED __attribute__((__packed__))
 #endif
 
-#ifndef LTTNG_HIDDEN
+/*
+ * LTTNG_HIDDEN: set the hidden attribute for internal functions
+ * On Windows, symbols are local unless explicitly exported,
+ * see https://gcc.gnu.org/wiki/Visibility
+ */
+#if defined(_WIN32) || defined(__CYGWIN__)
+#define LTTNG_HIDDEN
+#else
 #define LTTNG_HIDDEN __attribute__((visibility("hidden")))
 #endif
 
+#define member_sizeof(type, field)     sizeof(((type *) 0)->field)
+
+/*
+ * Get an aligned pointer to a value. This is meant
+ * as a helper to pass an aligned pointer to a member in a packed structure
+ * to a function.
+ */
+#define ALIGNED_CONST_PTR(value) (((const typeof(value) []) { value }))
+
 /*
  * lttng_strncpy returns 0 on success, or nonzero on failure.
  * It checks that the @src string fits into @dst_len before performing
@@ -87,7 +104,7 @@ void *zmalloc(size_t len)
 static inline
 int lttng_strncpy(char *dst, const char *src, size_t dst_len)
 {
-       if (strnlen(src, dst_len) == dst_len) {
+       if (lttng_strnlen(src, dst_len) == dst_len) {
                /* Fail since copying would result in truncation. */
                return -1;
        }