Commit ca6279d1 authored Feb 03, 2024 by Masahiro Yamada Committed by Sasha Levin Mar 26, 2024

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: 104daea1 ("kconfig: reference environment variables directly and remove 'option env='")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent a8cc354a

scripts/kconfig/lexer.l

+5 −2

Original line number	Diff line number	Diff line
		@@ -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;