[PATCH 05/13] kallsyms: refactor {,module_}kallsyms_on_each_symbol

[Christoph Hellwig]

Require an explicit call to module_kallsyms_on_each_symbol to look
for symbols in modules instead of the call from kallsyms_on_each_symbol,
and acquire module_mutex inside of module_kallsyms_on_each_symbol instead
of leaving that up to the caller.

Signed-off-by: Christoph Hellwig <h...@lst.de>
---
 kernel/kallsyms.c       | 6 +++++-
 kernel/livepatch/core.c | 6 +-----
 kernel/module.c         | 8 ++++----
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index fe9de067771c34..a0d3f0865916f9 100644
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -177,6 +177,10 @@ unsigned long kallsyms_lookup_name(const char *name)
        return module_kallsyms_lookup_name(name);
 }
 
+/*
+ * Iterate over all symbols in vmlinux.  For symbols from modules use
+ * module_kallsyms_on_each_symbol instead.
+ */
 int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *,
                                      unsigned long),
                            void *data)
@@ -192,7 +196,7 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, 
struct module *,
                if (ret != 0)
                        return ret;
        }
-       return module_kallsyms_on_each_symbol(fn, data);
+       return 0;
 }
 
 static unsigned long get_symbol_pos(unsigned long addr,
diff --git a/kernel/livepatch/core.c b/kernel/livepatch/core.c
index 262cd9b003b9f0..f591dac5e86ef4 100644
--- a/kernel/livepatch/core.c
+++ b/kernel/livepatch/core.c
@@ -164,12 +164,8 @@ static int klp_find_object_symbol(const char *objname, 
const char *name,
                .pos = sympos,
        };
 
-       mutex_lock(&module_mutex);
-       if (objname)
+       if (objname || !kallsyms_on_each_symbol(klp_find_callback, &args))
                module_kallsyms_on_each_symbol(klp_find_callback, &args);
-       else
-               kallsyms_on_each_symbol(klp_find_callback, &args);
-       mutex_unlock(&module_mutex);
 
        /*
         * Ensure an address was found. If sympos is 0, ensure symbol is unique;
diff --git a/kernel/module.c b/kernel/module.c
index 6772fb2680eb3e..ae9045c5292a78 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4379,8 +4379,7 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, 
const char *,
        unsigned int i;
        int ret;
 
-       module_assert_mutex();
-
+       mutex_lock(&module_mutex);
        list_for_each_entry(mod, &modules, list) {
                /* We hold module_mutex: no need for rcu_dereference_sched */
                struct mod_kallsyms *kallsyms = mod->kallsyms;
@@ -4396,10 +4395,11 @@ int module_kallsyms_on_each_symbol(int (*fn)(void *, 
const char *,
                        ret = fn(data, kallsyms_symbol_name(kallsyms, i),
                                 mod, kallsyms_symbol_value(sym));
                        if (ret != 0)
-                               return ret;
+                               break;
                }
        }
-       return 0;
+       mutex_unlock(&module_mutex);
+       return ret;
 }
 #endif /* CONFIG_KALLSYMS */
 
-- 
2.29.2