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authorMasahiro Yamada <masahiroy@kernel.org>2023-06-11 18:50:56 +0300
committerMasahiro Yamada <masahiroy@kernel.org>2023-06-22 15:21:06 +0300
commit700c48b439921b67715e25380e0f67e6e490d7b8 (patch)
treee78ec4cda73a6324761c9f6f5da089e6cf33e7a6 /scripts/mod/modpost.c
parent6e7611c485315a0e4e36c763d0810677e1f26ecd (diff)
downloadlinux-700c48b439921b67715e25380e0f67e6e490d7b8.tar.xz
modpost: use null string instead of NULL pointer for default namespace
The default namespace is the null string, "". When set, the null string "" is converted to NULL: s->namespace = namespace[0] ? NOFAIL(strdup(namespace)) : NULL; When printed, the NULL pointer is get back to the null string: sym->namespace ?: "" This saves 1 byte memory allocated for "", but loses the readability. In kernel-space, we strive to save memory, but modpost is a userspace tool used to build the kernel. On modern systems, such small piece of memory is not a big deal. Handle the namespace string as is. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Diffstat (limited to 'scripts/mod/modpost.c')
-rw-r--r--scripts/mod/modpost.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index bc9ef40ac620..a7c979b0ea21 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -300,6 +300,13 @@ static bool contains_namespace(struct list_head *head, const char *namespace)
{
struct namespace_list *list;
+ /*
+ * The default namespace is null string "", which is always implicitly
+ * contained.
+ */
+ if (!namespace[0])
+ return true;
+
list_for_each_entry(list, head, list) {
if (!strcmp(list->namespace, namespace))
return true;
@@ -369,7 +376,7 @@ static struct symbol *sym_add_exported(const char *name, struct module *mod,
s = alloc_symbol(name);
s->module = mod;
s->is_gpl_only = gpl_only;
- s->namespace = namespace[0] ? NOFAIL(strdup(namespace)) : NULL;
+ s->namespace = NOFAIL(strdup(namespace));
list_add_tail(&s->list, &mod->exported_symbols);
hash_add_symbol(s);
@@ -1829,8 +1836,7 @@ static void check_exports(struct module *mod)
else
basename = mod->name;
- if (exp->namespace &&
- !contains_namespace(&mod->imported_namespaces, exp->namespace)) {
+ if (!contains_namespace(&mod->imported_namespaces, exp->namespace)) {
modpost_log(allow_missing_ns_imports ? LOG_WARN : LOG_ERROR,
"module %s uses symbol %s from namespace %s, but does not import it.\n",
basename, exp->name, exp->namespace);
@@ -1916,8 +1922,7 @@ static void add_exported_symbols(struct buffer *buf, struct module *mod)
list_for_each_entry(sym, &mod->exported_symbols, list)
buf_printf(buf, "KSYMTAB_%s(%s, \"%s\", \"%s\");\n",
sym->is_func ? "FUNC" : "DATA", sym->name,
- sym->is_gpl_only ? "_gpl" : "",
- sym->namespace ?: "");
+ sym->is_gpl_only ? "_gpl" : "", sym->namespace);
if (!modversions)
return;
@@ -2185,7 +2190,7 @@ static void write_dump(const char *fname)
buf_printf(&buf, "0x%08x\t%s\t%s\tEXPORT_SYMBOL%s\t%s\n",
sym->crc, sym->name, mod->name,
sym->is_gpl_only ? "_GPL" : "",
- sym->namespace ?: "");
+ sym->namespace);
}
}
write_buf(&buf, fname);