9 files changed, 60 insertions, 31 deletions
diff --git a/src/v4l2/v4l2_camera.cpp b/src/v4l2/v4l2_camera.cpp
index 7b97c2d5..0f3b862f 100644
--- a/src/v4l2/v4l2_camera.cpp
+++ b/src/v4l2/v4l2_camera.cpp
@@ -2,7 +2,7 @@
 /*
  * Copyright (C) 2019, Google Inc.
  *
- * v4l2_camera.cpp - V4L2 compatibility camera
+ * V4L2 compatibility camera
  */
 
 #include "v4l2_camera.h"
diff --git a/src/v4l2/v4l2_camera.h b/src/v4l2/v4l2_camera.h
index d3483444..278cc33e 100644
--- a/src/v4l2/v4l2_camera.h
+++ b/src/v4l2/v4l2_camera.h
@@ -2,7 +2,7 @@
 /*
  * Copyright (C) 2019, Google Inc.
  *
- * v4l2_camera.h - V4L2 compatibility camera
+ * V4L2 compatibility camera
  */
 
 #pragma once
diff --git a/src/v4l2/v4l2_camera_file.cpp b/src/v4l2/v4l2_camera_file.cpp
index 0a41587c..d8fe854b 100644
--- a/src/v4l2/v4l2_camera_file.cpp
+++ b/src/v4l2/v4l2_camera_file.cpp
@@ -2,7 +2,7 @@
 /*
  * Copyright (C) 2020, Google Inc.
  *
- * v4l2_camera_file.h - V4L2 compatibility camera file information
+ * V4L2 compatibility camera file information
  */
 
 #include "v4l2_camera_file.h"
diff --git a/src/v4l2/v4l2_camera_file.h b/src/v4l2/v4l2_camera_file.h
index 1a7b6a63..1212989e 100644
--- a/src/v4l2/v4l2_camera_file.h
+++ b/src/v4l2/v4l2_camera_file.h
@@ -2,7 +2,7 @@
 /*
  * Copyright (C) 2020, Google Inc.
  *
- * v4l2_camera_file.h - V4L2 compatibility camera file information
+ * V4L2 compatibility camera file information
  */
 
 #pragma once
diff --git a/src/v4l2/v4l2_camera_proxy.cpp b/src/v4l2/v4l2_camera_proxy.cpp
index 341f7902..3f7c00a2 100644
--- a/src/v4l2/v4l2_camera_proxy.cpp
+++ b/src/v4l2/v4l2_camera_proxy.cpp
@@ -2,7 +2,7 @@
 /*
  * Copyright (C) 2019, Google Inc.
  *
- * v4l2_camera_proxy.cpp - Proxy to V4L2 compatibility camera
+ * Proxy to V4L2 compatibility camera
  */
 
 #include "v4l2_camera_proxy.h"
diff --git a/src/v4l2/v4l2_camera_proxy.h b/src/v4l2/v4l2_camera_proxy.h
index 8a0195e1..3d8784df 100644
--- a/src/v4l2/v4l2_camera_proxy.h
+++ b/src/v4l2/v4l2_camera_proxy.h
@@ -2,7 +2,7 @@
 /*
  * Copyright (C) 2019, Google Inc.
  *
- * v4l2_camera_proxy.h - Proxy to V4L2 compatibility camera
+ * Proxy to V4L2 compatibility camera
  */
 
 #pragma once
diff --git a/src/v4l2/v4l2_compat.cpp b/src/v4l2/v4l2_compat.cpp
index 1765fb5d..66468bf3 100644
--- a/src/v4l2/v4l2_compat.cpp
+++ b/src/v4l2/v4l2_compat.cpp
@@ -2,17 +2,20 @@
 /*
  * Copyright (C) 2019, Google Inc.
  *
- * v4l2_compat.cpp - V4L2 compatibility layer
+ * V4L2 compatibility layer
  */
 
 #include "v4l2_compat_manager.h"
 
+#include <assert.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <stdarg.h>
+#include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/stat.h>
 #include <sys/types.h>
+#include <unistd.h>
 
 #include <libcamera/base/utils.h>
 
@@ -28,71 +31,97 @@ using namespace libcamera;
 	va_end(ap);			\
 }
 
+namespace {
+
+/*
+ * Determine if the flags require a further mode arguments that needs to be
+ * parsed from va_args.
+ */
+bool needs_mode(int flags)
+{
+	return (flags & O_CREAT) || ((flags & O_TMPFILE) == O_TMPFILE);
+}
+
+} /* namespace */
+
 extern "C" {
 
 LIBCAMERA_PUBLIC int open(const char *path, int oflag, ...)
 {
 	mode_t mode = 0;
-	if (oflag & O_CREAT || oflag & O_TMPFILE)
+	if (needs_mode(oflag))
 		extract_va_arg(mode_t, mode, oflag);
 
 	return V4L2CompatManager::instance()->openat(AT_FDCWD, path,
 						     oflag, mode);
 }
 
-/* _FORTIFY_SOURCE redirects open to __open_2 */
-LIBCAMERA_PUBLIC int __open_2(const char *path, int oflag)
-{
-	return open(path, oflag);
-}
-
 #ifndef open64
 LIBCAMERA_PUBLIC int open64(const char *path, int oflag, ...)
 {
 	mode_t mode = 0;
-	if (oflag & O_CREAT || oflag & O_TMPFILE)
+	if (needs_mode(oflag))
 		extract_va_arg(mode_t, mode, oflag);
 
 	return V4L2CompatManager::instance()->openat(AT_FDCWD, path,
 						     oflag | O_LARGEFILE, mode);
 }
-
-LIBCAMERA_PUBLIC int __open64_2(const char *path, int oflag)
-{
-	return open(path, oflag);
-}
 #endif
 
 LIBCAMERA_PUBLIC int openat(int dirfd, const char *path, int oflag, ...)
 {
 	mode_t mode = 0;
-	if (oflag & O_CREAT || oflag & O_TMPFILE)
+	if (needs_mode(oflag))
 		extract_va_arg(mode_t, mode, oflag);
 
 	return V4L2CompatManager::instance()->openat(dirfd, path, oflag, mode);
 }
 
-LIBCAMERA_PUBLIC int __openat_2(int dirfd, const char *path, int oflag)
-{
-	return openat(dirfd, path, oflag);
-}
-
 #ifndef openat64
 LIBCAMERA_PUBLIC int openat64(int dirfd, const char *path, int oflag, ...)
 {
 	mode_t mode = 0;
-	if (oflag & O_CREAT || oflag & O_TMPFILE)
+	if (needs_mode(oflag))
 		extract_va_arg(mode_t, mode, oflag);
 
 	return V4L2CompatManager::instance()->openat(dirfd, path,
 						     oflag | O_LARGEFILE, mode);
 }
+#endif
 
-LIBCAMERA_PUBLIC int __openat64_2(int dirfd, const char *path, int oflag)
+/*
+ * _FORTIFY_SOURCE redirects open* to __open*_2. Disable the
+ * -Wmissing-declarations warnings, as the functions won't be declared if
+ *  _FORTIFY_SOURCE is not in use.
+ */
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wmissing-declarations"
+
+LIBCAMERA_PUBLIC int __open_2(const char *path, int oflag)
+{
+	assert(!needs_mode(oflag));
+	return open(path, oflag);
+}
+
+LIBCAMERA_PUBLIC int __open64_2(const char *path, int oflag)
 {
+	assert(!needs_mode(oflag));
+	return open64(path, oflag);
+}
+
+LIBCAMERA_PUBLIC int __openat_2(int dirfd, const char *path, int oflag)
+{
+	assert(!needs_mode(oflag));
 	return openat(dirfd, path, oflag);
 }
-#endif
+
+LIBCAMERA_PUBLIC int __openat64_2(int dirfd, const char *path, int oflag)
+{
+	assert(!needs_mode(oflag));
+	return openat64(dirfd, path, oflag);
+}
+
+#pragma GCC diagnostic pop
 
 LIBCAMERA_PUBLIC int dup(int oldfd)
 {
diff --git a/src/v4l2/v4l2_compat_manager.cpp b/src/v4l2/v4l2_compat_manager.cpp
index 5e8cdb4f..6a00afb5 100644
--- a/src/v4l2/v4l2_compat_manager.cpp
+++ b/src/v4l2/v4l2_compat_manager.cpp
@@ -2,7 +2,7 @@
 /*
  * Copyright (C) 2019, Google Inc.
  *
- * v4l2_compat_manager.cpp - V4L2 compatibility manager
+ * V4L2 compatibility manager
  */
 
 #include "v4l2_compat_manager.h"
diff --git a/src/v4l2/v4l2_compat_manager.h b/src/v4l2/v4l2_compat_manager.h
index 64af9a8c..f7c6f122 100644
--- a/src/v4l2/v4l2_compat_manager.h
+++ b/src/v4l2/v4l2_compat_manager.h
@@ -2,7 +2,7 @@
 /*
  * Copyright (C) 2019, Google Inc.
  *
- * v4l2_compat_manager.h - V4L2 compatibility manager
+ * V4L2 compatibility manager
  */
 
 #pragma once