[PATCH] Add kallsyms_lookupname()

From: Rusty Russell <rusty@au1.ibm.com>

Attached patch adds a kallsyms_lookupname() function for lookups of a
symbol name to an address.  Debuggers such as ppc[64] xmon can use this.

It's intentionally not exported as a symbol for module use, since it
can be used to circumvent other symbol export restrictions.

2 files changed, 17 insertions, 0 deletions

diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index d2a90b7766a1..87b9bbbb485e 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -8,6 +8,9 @@
 #include <linux/config.h>
 
 #ifdef CONFIG_KALLSYMS
+/* Lookup the address for a symbol. Returns 0 if not found. */
+unsigned long kallsyms_lookup_name(const char *name);
+
 /* Lookup an address.  modname is set to NULL if it's in the kernel. */
 const char *kallsyms_lookup(unsigned long addr,
 			    unsigned long *symbolsize,
@@ -19,6 +22,11 @@ extern void __print_symbol(const char *fmt, unsigned long address);
 
 #else /* !CONFIG_KALLSYMS */
 
+static inline unsigned long kallsyms_lookup_name(const char *name)
+{
+	return 0;
+}
+
 static inline const char *kallsyms_lookup(unsigned long addr,
 					  unsigned long *symbolsize,
 					  unsigned long *offset,
diff --git a/include/linux/module.h b/include/linux/module.h
index 95cbc9b4936f..e01784890022 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -282,6 +282,10 @@ struct module *module_get_kallsym(unsigned int symnum,
 				  unsigned long *value,
 				  char *type,
 				  char namebuf[128]);
+
+/* Look for this name: can be of form module:name. */
+unsigned long module_kallsyms_lookup_name(const char *name);
+
 int is_exported(const char *name, const struct module *mod);
 
 extern void __module_put_and_exit(struct module *mod, long code)
@@ -434,6 +438,11 @@ static inline struct module *module_get_kallsym(unsigned int symnum,
 	return NULL;
 }
 
+static inline unsigned long module_kallsyms_lookup_name(const char *name)
+{
+	return 0;
+}
+
 static inline int is_exported(const char *name, const struct module *mod)
 {
 	return 0;