From 97446b3c326efbca9698876c41d2d309ea0f229b Mon Sep 17 00:00:00 2001
From: Andy Whitcroft <apw@canonical.com>
Date: Thu, 27 Nov 2008 19:12:07 +0000
Subject: [PATCH] UBUNTU: SAUCE: (no-up) version: Implement version_signature
 proc file.

Signed-off-by: Andy Whitcroft <apw@canonical.com>
Acked-by: Tim Gardener <tim.gardner@canonical.com>
---
 fs/proc/Makefile            |  2 +-
 fs/proc/version_signature.c | 31 +++++++++++++++++++++++++++++++
 init/Kconfig                |  9 +++++++++
 init/version-timestamp.c    |  6 +++++-
 4 files changed, 46 insertions(+), 2 deletions(-)
 create mode 100644 fs/proc/version_signature.c

diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index bd08616ed8ba..de9b299be9fc 100644
--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -33,4 +33,4 @@ proc-$(CONFIG_PROC_KCORE)	+= kcore.o
 proc-$(CONFIG_PROC_VMCORE)	+= vmcore.o
 proc-$(CONFIG_PRINTK)	+= kmsg.o
 proc-$(CONFIG_PROC_PAGE_MONITOR)	+= page.o
-proc-$(CONFIG_BOOT_CONFIG)	+= bootconfig.o
+proc-$(CONFIG_BOOT_CONFIG)	+= bootconfig.o version_signature.o
diff --git a/fs/proc/version_signature.c b/fs/proc/version_signature.c
new file mode 100644
index 000000000000..27d775d87d9f
--- /dev/null
+++ b/fs/proc/version_signature.c
@@ -0,0 +1,31 @@
+#include <linux/fs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/utsname.h>
+
+static int version_signature_proc_show(struct seq_file *m, void *v)
+{
+	seq_printf(m, "%s\n", CONFIG_VERSION_SIGNATURE);
+	return 0;
+}
+
+static int version_signature_proc_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, version_signature_proc_show, NULL);
+}
+
+static const struct proc_ops version_signature_proc_fops = {
+	.proc_open	= version_signature_proc_open,
+	.proc_read	= seq_read,
+	.proc_lseek	= seq_lseek,
+	.proc_release	= single_release,
+};
+
+static int __init proc_version_signature_init(void)
+{
+	proc_create("version_signature", 0, NULL, &version_signature_proc_fops);
+	return 0;
+}
+module_init(proc_version_signature_init);
diff --git a/init/Kconfig b/init/Kconfig
index bee58f7468c3..ec9426c3567d 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -376,6 +376,15 @@ config DEFAULT_HOSTNAME
 	  but you may wish to use a different default here to make a minimal
 	  system more usable with less configuration.
 
+config VERSION_SIGNATURE
+	string "Arbitrary version signature"
+	help
+	  This string will be created in a file, /proc/version_signature. It
+	  is useful in determining arbitrary data about your kernel. For instance,
+	  if you have several kernels of the same version, but need to keep track
+	  of a revision of the same kernel, but not affect it's ability to load
+	  compatible modules, this is the easiest way to do that.
+
 config SYSVIPC
 	bool "System V IPC"
 	help
diff --git a/init/version-timestamp.c b/init/version-timestamp.c
index 043cbf80a766..649275e25ff4 100644
--- a/init/version-timestamp.c
+++ b/init/version-timestamp.c
@@ -27,4 +27,8 @@ struct uts_namespace init_uts_ns = {
 /* FIXED STRINGS! Don't touch! */
 const char linux_banner[] =
 	"Linux version " UTS_RELEASE " (" LINUX_COMPILE_BY "@"
-	LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION "\n";
+	LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION
+#ifdef CONFIG_VERSION_SIGNATURE
+	" (" CONFIG_VERSION_SIGNATURE ")"
+#endif
+	"\n";