Fix CI: guard cloexec wrappers for linuxkm/Windows/OS2

Exclude WOLFSSL_LINUXKM from the POSIX wrapper block so kernel builds
don't try to include <fcntl.h>/<sys/socket.h>. For platforms without
POSIX close-on-exec (Windows, OS/2 Open Watcom, linuxkm, Zephyr),
define the wrappers as macros that pass through to plain syscalls,
letting call sites stay unconditional.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: embhorn

wolfcrypt/src/wc_port.c

@@ -20,7 +20,8 @@
  */
 
 #if (defined(__linux__) || defined(__ANDROID__)) && \
-    !defined(WOLFSSL_ZEPHYR) && !defined(_GNU_SOURCE)
+    !defined(WOLFSSL_LINUXKM) && !defined(WOLFSSL_ZEPHYR) && \
+    !defined(_GNU_SOURCE)
     #define _GNU_SOURCE 1
 #endif
 
@@ -5135,7 +5136,8 @@ char* wolfSSL_strnstr(const char* s1, const char* s2, unsigned int n)
 
 #endif /* not SINGLE_THREADED */
 
-#if (defined(__unix__) || defined(__APPLE__)) && !defined(WOLFSSL_ZEPHYR)
+#if (defined(__unix__) || defined(__APPLE__)) && \
+    !defined(WOLFSSL_LINUXKM) && !defined(WOLFSSL_ZEPHYR)
 
 #include <fcntl.h>
 #include <errno.h>
@@ -5202,7 +5204,7 @@ int wc_accept_cloexec(int sockfd, void* addr, void* addrlen)
     return fd;
 }
 
-#endif /* __unix__ || __APPLE__ */
+#endif /* (__unix__ || __APPLE__) && !WOLFSSL_LINUXKM && !WOLFSSL_ZEPHYR */
 
 #if defined(WOLFSSL_LINUXKM) && defined(CONFIG_ARM64) && \
     defined(WC_SYM_RELOC_TABLES)

wolfssl/wolfcrypt/wc_port.h

@@ -1860,11 +1860,22 @@ WOLFSSL_ABI WOLFSSL_API int wolfCrypt_Cleanup(void);
     #define WC_GENERATE_SEED_DEFAULT wc_GenerateSeed
 #endif
 
-#if (defined(__unix__) || defined(__APPLE__)) && !defined(WOLFSSL_ZEPHYR)
+#if (defined(__unix__) || defined(__APPLE__)) && \
+    !defined(WOLFSSL_LINUXKM) && !defined(WOLFSSL_ZEPHYR)
     WOLFSSL_LOCAL void wc_set_cloexec(int fd);
     WOLFSSL_LOCAL int wc_open_cloexec(const char* path, int flags);
     WOLFSSL_LOCAL int wc_socket_cloexec(int domain, int type, int protocol);
     WOLFSSL_LOCAL int wc_accept_cloexec(int sockfd, void* addr, void* addrlen);
+#else
+    /* Platforms without POSIX close-on-exec semantics (Windows, OS/2 OW,
+     * Linux kernel module, Zephyr, etc.): pass through to plain syscalls
+     * where the underlying headers are available in the caller. */
+    #define wc_set_cloexec(fd) ((void)(fd))
+    #define wc_open_cloexec(path, flags) open((path), (flags))
+    #define wc_socket_cloexec(domain, type, protocol) \
+        socket((domain), (type), (protocol))
+    #define wc_accept_cloexec(sockfd, addr, addrlen) \
+        accept((sockfd), (addr), (addrlen))
 #endif
 
 #ifdef __cplusplus