Fix race between cat /proc/slab_allocators and rmmod

Same story as with cat /proc/*/wchan race vs rmmod race, only
/proc/slab_allocators want more info than just symbol name.

Signed-off-by: Alexey Dobriyan <adobriyan@sw.ru>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 7 deletions

diff --git a/mm/slab.c b/mm/slab.c
index 1115e2065bfc..acda7e2d66e4 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -4432,16 +4432,12 @@ static void handle_slab(unsigned long *n, struct kmem_cache *c, struct slab *s)
 static void show_symbol(struct seq_file *m, unsigned long address)
 {
 #ifdef CONFIG_KALLSYMS
-        char *modname;
-        const char *name;
         unsigned long offset, size;
-        char namebuf[KSYM_NAME_LEN+1];
-
-        name = kallsyms_lookup(address, &size, &offset, &modname, namebuf);
+        char modname[MODULE_NAME_LEN + 1], name[KSYM_NAME_LEN + 1];
 
-        if (name) {
+        if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) {
                 seq_printf(m, "%s+%#lx/%#lx", name, offset, size);
-                if (modname)
+                if (modname[0])
                         seq_printf(m, " [%s]", modname);
                 return;
         }