[PATCH v4 04/31] kconfig: remove string expansion in file_lookup()

Masahiro Yamada
2018-05-17T06:18:51Z

There are two callers of file_lookup(), but there is no more reason
to expand the given path.

[1] zconf_initscan()
This is used to open the first Kconfig. sym_expand_string_value()
has never been used in a useful way here; before opening the first
Kconfig file, obviously there is no symbol to expand. If you use
expand_string_value() instead, environments in KBUILD_KCONFIG would
be expanded, but I do not see practical benefits for that.

[2] zconf_nextfile()
This is used to open the next file from 'source' statement.
Symbols in the path like "arch/$SRCARCH/Kconfig" needed expanding,
but it was replaced with the direct environment expansion. The
environment has already been expanded before the token is passed
to the parser.

By the way, file_lookup() was already buggy; it expanded a given path,
but it used the path before expansion for look-up:
if (!strcmp(name, file->name)) {

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Ulf Magnusson <ulfalizer@gmail.com>
---

Changes in v4: None
Changes in v3: None
Changes in v2:
- Simplify the patch. Just remove text expansion.

scripts/kconfig/util.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/scripts/kconfig/util.c b/scripts/kconfig/util.c
index 807147e..790967df 100644
--- a/scripts/kconfig/util.c
+++ b/scripts/kconfig/util.c
@@ -14,18 +14,16 @@
struct file *file_lookup(const char *name)
{
struct file *file;
- char *file_name = sym_expand_string_value(name);

for (file = file_list; file; file = file->next) {
if (!strcmp(name, file->name)) {
- free(file_name);
return file;
}
}

file = xmalloc(sizeof(*file));
memset(file, 0, sizeof(*file));
- file->name = file_name;
+ file->name = xstrdup(name);
file->next = file_list;
file_list = file;
return file;
--
2.7.4