From dedf1a79be0dffb625192b0f7d75e2cfb8aab4d0 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Mon, 1 Jun 2020 14:57:19 +0900 Subject: [PATCH] modpost: avoid false-positive file open error One problem of grab_file() is that it cannot distinguish the following two cases: - It cannot read the file (the file does not exist, or read permission is not set) - It can read the file, but the file size is zero This is because grab_file() calls mmap(), which requires the mapped length is greater than 0. Hence, grab_file() fails for both cases. If an empty header file were included for checksum calculation, the following warning would be printed: WARNING: modpost: could not open ...: Invalid argument An empty file is a valid source file, so it should not fail. Use read_text_file() instead. It can read a zero-length file. Then, parse_file() will succeed with doing nothing. Going forward, the first case (it cannot read the file) is a fatal error. If the source file from which an object was compiled is missing, something went wrong. Signed-off-by: Masahiro Yamada --- scripts/mod/sumversion.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/scripts/mod/sumversion.c b/scripts/mod/sumversion.c index 5fb142db61957..9f77c9dfce205 100644 --- a/scripts/mod/sumversion.c +++ b/scripts/mod/sumversion.c @@ -258,9 +258,8 @@ static int parse_file(const char *fname, struct md4_ctx *md) char *file; unsigned long i, len; - file = grab_file(fname, &len); - if (!file) - return 0; + file = read_text_file(fname); + len = strlen(file); for (i = 0; i < len; i++) { /* Collapse and ignore \ and CR. */ @@ -287,7 +286,7 @@ static int parse_file(const char *fname, struct md4_ctx *md) add_char(file[i], md); } - release_file(file, len); + free(file); return 1; } /* Check whether the file is a static library or not */ -- 2.39.5