From 87ddba29e72be6b6594c26d0f9388346d30e5bf1 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Sat, 3 Feb 2024 00:57:59 +0900 Subject: [PATCH] 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 Signed-off-by: Sasha Levin --- scripts/kconfig/lexer.l | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/scripts/kconfig/lexer.l b/scripts/kconfig/lexer.l index 240109f965ae..72e5e9ac52bb 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;