Add the sysctl "kern.function_list", which currently exports all

function symbols in the kernel in a list of C strings, with an extra
nul-termination at the end.

This sysctl requires addition of a new linker operation.  Now,
linker_file_t's need to respond to "each_function_name" to export
their function symbols.

Note that the sysctl doesn't currently allow distinguishing multiple
symbols with the same name from different modules, but could quite
easily without a change to the linker operation.  This will be a nicety
to have when it can be used.

Obtained from:	NAI Labs CBOSS project
Funded by:	DARPA

1 files changed, 31 insertions, 0 deletions

diff --git a/sys/kern/kern_linker.c b/sys/kern/kern_linker.c
index 353d811..7c2b59d 100644
--- a/sys/kern/kern_linker.c
+++ b/sys/kern/kern_linker.c
@@ -1702,3 +1702,34 @@ linker_load_dependancies(linker_file_t lf)
     linker_addmodules(lf, start, stop, 0);
     return error;
 }
+
+static int
+sysctl_kern_function_list_iterate(const char *name, void *opaque)
+{
+	struct sysctl_req *req;
+
+	req = opaque;
+	return (SYSCTL_OUT(req, name, strlen(name) + 1));
+}
+
+/*
+ * Export a nul-separated, double-nul-terminated list of all function names
+ * in the kernel.
+ */
+static int
+sysctl_kern_function_list(SYSCTL_HANDLER_ARGS)
+{
+	linker_file_t lf;
+	int error;
+
+	TAILQ_FOREACH(lf, &linker_files, link) {
+		error = LINKER_EACH_FUNCTION_NAME(lf,
+		    sysctl_kern_function_list_iterate, req);
+		if (error)
+			return (error);
+	}
+	return (SYSCTL_OUT(req, "", 1));
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, function_list, CTLFLAG_RD,
+	NULL, 0, sysctl_kern_function_list, "", "kernel function list");