[PATCH] tracing: Make undefsyms_base.c a first-class citizen

[Marc Zyngier <maz@kernel.org>]

Linus points out that dumping undefsyms_base.c form the Makefile
is rather ugly, and that a much better course of action would be
to have this file as a first-class citizen in the git tree.

This allows some extra cleanup in the Makefile, and the removal of
the .gitignore file in kernel/trace.

Link: https://lore.kernel.org/r/CAHk-=wieqGd_XKpu8UxDoyADZx8TDe8CF3RmkUXt5N_9t5Pf_w@mail.gmail.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Vincent Donnefort <vdonnefort@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnd Bergmann <arnd@arndb.de>
---
 kernel/trace/.gitignore       |  1 -
 kernel/trace/Makefile         | 23 -----------------------
 kernel/trace/undefsyms_base.c | 14 ++++++++++++++
 3 files changed, 14 insertions(+), 24 deletions(-)
 delete mode 100644 kernel/trace/.gitignore
 create mode 100644 kernel/trace/undefsyms_base.c

diff --git a/kernel/trace/.gitignore b/kernel/trace/.gitignore
deleted file mode 100644
index 6adbb09d6deb0..0000000000000
--- a/kernel/trace/.gitignore
+++ /dev/null
@@ -1 +0,0 @@
-/undefsyms_base.c
diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile
index 4d4229e5eec4b..0b0b8f5b9d2bf 100644
--- a/kernel/trace/Makefile
+++ b/kernel/trace/Makefile
@@ -140,29 +140,6 @@ obj-$(CONFIG_TRACE_REMOTE_TEST) += remote_test.o
 # undefsyms_base generates a set of compiler and tooling-generated symbols that can
 # safely be ignored for simple_ring_buffer.
 #
-filechk_undefsyms_base = \
-	echo '$(pound)include <linux/atomic.h>'; \
-	echo '$(pound)include <linux/string.h>'; \
-	echo '$(pound)include <asm/page.h>'; \
-	echo 'static char page[PAGE_SIZE] __aligned(PAGE_SIZE);'; \
-	echo 'void undefsyms_base(void *p, int n);'; \
-	echo 'void undefsyms_base(void *p, int n) {'; \
-	echo '	char buffer[256] = { 0 };'; \
-	echo '	u32 u = 0;'; \
-	echo '	memset((char * volatile)page, 8, PAGE_SIZE);'; \
-	echo '	memset((char * volatile)buffer, 8, sizeof(buffer));'; \
-	echo '	memcpy((void * volatile)p, buffer, sizeof(buffer));'; \
-	echo '	cmpxchg((u32 * volatile)&u, 0, 8);'; \
-	echo '	WARN_ON(n == 0xdeadbeef);'; \
-	echo '}'
-
-$(obj)/undefsyms_base.c: FORCE
-	$(call filechk,undefsyms_base)
-
-clean-files += undefsyms_base.c
-
-$(obj)/undefsyms_base.o: $(obj)/undefsyms_base.c
-
 targets += undefsyms_base.o
 
 # Ensure KASAN is enabled to avoid logic that may disable FORTIFY_SOURCE when
diff --git a/kernel/trace/undefsyms_base.c b/kernel/trace/undefsyms_base.c
new file mode 100644
index 0000000000000..3db5adf918cce
--- /dev/null
+++ b/kernel/trace/undefsyms_base.c
@@ -0,0 +1,14 @@
+#include <linux/atomic.h>
+#include <linux/string.h>
+#include <asm/page.h>
+static char page[PAGE_SIZE] __aligned(PAGE_SIZE);
+void undefsyms_base(void *p, int n);
+void undefsyms_base(void *p, int n) {
+	char buffer[256] = { 0 };
+	u32 u = 0;
+	memset((char * volatile)page, 8, PAGE_SIZE);
+	memset((char * volatile)buffer, 8, sizeof(buffer));
+	memcpy((void * volatile)p, buffer, sizeof(buffer));
+	cmpxchg((u32 * volatile)&u, 0, 8);
+	WARN_ON(n == 0xdeadbeef);
+}
-- 
2.47.3