This is a note to let you know that I've just added the patch titled
kconfig: fix infinite loop when expanding a macro at the end of file
to the 5.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
kconfig-fix-infinite-loop-when-expanding-a-macro-at-.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 634fcc9b311f4f725827b3588121ff3e537ba8c4
Author: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Date: Sat Feb 3 00:57:59 2024 +0900
kconfig: fix infinite loop when expanding a macro at the end of file
[ Upstream commit af8bbce92044dc58e4cc039ab94ee5d470a621f5 ]
A macro placed at the end of a file with no newline causes an infinite
loop.
[Test Kconfig]
$(info,hello)
\ No newline at end of file
I realized that flex-provided input() returns 0 instead of EOF when it
reaches the end of a file.
Fixes: 104daea149c4 ("kconfig: reference environment variables directly and remove 'option env='")
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/scripts/kconfig/lexer.l b/scripts/kconfig/lexer.l
index 6354c905b006f..3bf90d01c39f9 100644
--- a/scripts/kconfig/lexer.l
+++ b/scripts/kconfig/lexer.l
@@ -305,8 +305,11 @@ static char *expand_token(const char *in, size_t n)
new_string();
append_string(in, n);
- /* get the whole line because we do not know the end of token. */
- while ((c = input()) != EOF) {
+ /*
+ * get the whole line because we do not know the end of token.
+ * input() returns 0 (not EOF!) when it reachs the end of file.
+ */
+ while ((c = input()) != 0) {
if (c == '\n') {
unput(c);
break;
