[PATCH 1/1] UBUNTU: SAUCE: (no-up) version: Implement version_signature proc file.

[Andy Whitcroft]

It seems that the /proc/version_signature support in Jaunty was miss-merged.
A significant rejig of the fs/proc support has occured and we need to
redo this support basically.  The patch below looks like it would do the
job, though I have only compile tested it at this time.  This applies once
the miss-merge is reverted, commit 20391c6e76c6992bdb7027f8b6bdbe35845e909a.

Signed-off-by: Andy Whitcroft <apw at canonical.com>
---
 fs/proc/Makefile            |    1 +
 fs/proc/version_signature.c |   31 +++++++++++++++++++++++++++++++
 init/Kconfig                |    9 +++++++++
 init/version.c              |    6 +++++-
 4 files changed, 46 insertions(+), 1 deletions(-)
 create mode 100644 fs/proc/version_signature.c

diff --git a/fs/proc/Makefile b/fs/proc/Makefile
index 63d9651..8ab67f1 100644
--- a/fs/proc/Makefile
+++ b/fs/proc/Makefile
@@ -25,3 +25,4 @@ proc-$(CONFIG_PROC_VMCORE)	+= vmcore.o
 proc-$(CONFIG_PROC_DEVICETREE)	+= proc_devtree.o
 proc-$(CONFIG_PRINTK)	+= kmsg.o
 proc-$(CONFIG_PROC_PAGE_MONITOR)	+= page.o
+proc-$(CONFIG_VERSION_SIGNATURE)	+= version_signature.o
diff --git a/fs/proc/version_signature.c b/fs/proc/version_signature.c
new file mode 100644
index 0000000..534303e
--- /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", CONFIG_VERSION_SIGNATURE);
+	return 0;
+}
+
+static int version_proc_signature_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, version_signature_proc_show, NULL);
+}
+
+static const struct file_operations version_signature_proc_fops = {
+	.open		= version_signature_proc_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static int __init proc_signature_version_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 f763762..b4e9ae8 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -101,6 +101,15 @@ config LOCALVERSION_AUTO
 
 	  which is done within the script "scripts/setlocalversion".)
 
+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 SWAP
 	bool "Support for paging of anonymous memory (swap)"
 	depends on MMU && BLOCK
diff --git a/init/version.c b/init/version.c
index 52a8b98..9c8a867 100644
--- a/init/version.c
+++ b/init/version.c
@@ -39,7 +39,11 @@ EXPORT_SYMBOL_GPL(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";
 
 const char linux_proc_banner[] =
 	"%s version %s"
-- 
1.6.0.4.911.gc990