module: show version information for built-in modules in sysfs

Currently only drivers that are built as modules have their versions
shown in /sys/module/<module_name>/version, but this information might
also be useful for built-in drivers as well. This especially important
for drivers that do not define any parameters - such drivers, if
built-in, are completely invisible from userspace.

This patch changes MODULE_VERSION() macro so that in case when we are
compiling built-in module, version information is stored in a separate
section. Kernel then uses this data to create 'version' sysfs attribute
in the same fashion it creates attributes for module parameters.

Signed-off-by: Dmitry Torokhov <dtor@vmware.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 68649336c4ad..6ebb81030d2d 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -364,6 +364,13 @@
                 VMLINUX_SYMBOL(__start___param) = .;                    \
                 *(__param)                                              \
                 VMLINUX_SYMBOL(__stop___param) = .;                     \
+        }                                                               \
+                                                                        \
+        /* Built-in module versions. */                                 \
+        __modver : AT(ADDR(__modver) - LOAD_OFFSET) {                   \
+                VMLINUX_SYMBOL(__start___modver) = .;                   \
+                *(__modver)                                             \
+                VMLINUX_SYMBOL(__stop___modver) = .;                    \
                 . = ALIGN((align));                                     \
                 VMLINUX_SYMBOL(__end_rodata) = .;                       \
         }                                                               \