kallsyms: Skip the name search for empty string

When kallsyms_lookup_name is called with empty string,
it will do futile search for it through all the symbols.

Skipping the search for empty string.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220316122419.933957-3-jolsa@kernel.org

diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c
index 951c932..79f2eb6 100644 (file)
--- a/kernel/kallsyms.c
+++ b/kernel/kallsyms.c
@@ -212,6 +212,10 @@ unsigned long kallsyms_lookup_name(const char *name)
        unsigned long i;
        unsigned int off;
 
+       /* Skip the search for empty string. */
+       if (!*name)
+               return 0;
+
        for (i = 0, off = 0; i < kallsyms_num_syms; i++) {
                off = kallsyms_expand_symbol(off, namebuf, ARRAY_SIZE(namebuf));