kbuild: include core debug info when DEBUG_INFO_REDUCED

With CONFIG_DEBUG_INFO_REDUCED, we do get quite a lot of debug info
(around 22.7 MB for a defconfig+DEBUG_INFO_REDUCED). However, the
"basenames must match" rule used by -femit-struct-debug-baseonly
option means that we miss some core data structures, such as struct
{device, file, inode, mm_struct, page} etc.

We can easily get these included as well, while still getting the
benefits of CONFIG_DEBUG_INFO_REDUCED (faster build times and smaller
individual object files): All it takes is a dummy translation unit
including a few strategic headers and compiled with a flag overriding
-femit-struct-debug-baseonly.

This increases the size of .debug_info by ~0.3%, but these 90 KB
contain some rather useful info.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Michal Marek <mmarek@suse.cz>

1 files changed, 27 insertions, 0 deletions

diff --git a/lib/debug_info.c b/lib/debug_info.c
new file mode 100644
index 000000000000..2edbe27517ed
--- /dev/null
+++ b/lib/debug_info.c
@@ -0,0 +1,27 @@
+/*
+ * This file exists solely to ensure debug information for some core
+ * data structures is included in the final image even for
+ * CONFIG_DEBUG_INFO_REDUCED. Please do not add actual code. However,
+ * adding appropriate #includes is fine.
+ */
+#include <stdarg.h>
+
+#include <linux/cred.h>
+#include <linux/crypto.h>
+#include <linux/dcache.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/fscache-cache.h>
+#include <linux/io.h>
+#include <linux/kallsyms.h>
+#include <linux/kernel.h>
+#include <linux/kobject.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+#include <net/addrconf.h>
+#include <net/sock.h>
+#include <net/tcp.h>