Check for KALLSYMS

Check at ./configure time that the kernel was built with kallsyms
support.  If the kernel doesn't have CONFIG_KALLSYMS defined the
modules will still compile cleanly but will not be loadable.  So
we really want to catch this early during ./configure.  Note that
we do not require CONFIG_KALLSYMS_ALL but it may be safely defined.

Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #6

diff --git a/config/spl-build.m4 b/config/spl-build.m4
index dae1ac4fc1ff079be24cb2dcf4fc6e564f56651e..e9695de9a2b3dd6521ddedf536d1ffab73c17cab 100644 (file)
--- a/config/spl-build.m4
+++ b/config/spl-build.m4
@@ -82,6 +82,7 @@ AC_DEFUN([SPL_AC_CONFIG_KERNEL], [
        SPL_AC_KERN_PATH_PARENT_HEADER
        SPL_AC_KERN_PATH_PARENT_SYMBOL
        SPL_AC_KERN_PATH_LOCKED
+       SPL_AC_CONFIG_KALLSYMS
        SPL_AC_CONFIG_ZLIB_INFLATE
        SPL_AC_CONFIG_ZLIB_DEFLATE
        SPL_AC_2ARGS_ZLIB_DEFLATE_WORKSPACESIZE
@@ -2129,6 +2130,26 @@ AC_DEFUN([SPL_AC_KERN_PATH_LOCKED], [
                [])
 ])
 
+dnl #
+dnl # /proc/kallsyms support,
+dnl # Verify the kernel has CONFIG_KALLSYMS support enabled.
+dnl #
+AC_DEFUN([SPL_AC_CONFIG_KALLSYMS], [
+       AC_MSG_CHECKING([whether CONFIG_KALLSYMS is defined])
+       SPL_LINUX_TRY_COMPILE([
+               #if !defined(CONFIG_KALLSYMS)
+               #error CONFIG_KALLSYMS not defined
+               #endif
+       ],[ ],[
+               AC_MSG_RESULT([yes])
+       ],[
+               AC_MSG_RESULT([no])
+               AC_MSG_ERROR([
+       *** This kernel does not include the required kallsyms support.
+       *** Rebuild the kernel with CONFIG_KALLSYMS=y set.])
+       ])
+])
+
 dnl #
 dnl # zlib inflate compat,
 dnl # Verify the kernel has CONFIG_ZLIB_INFLATE support enabled.