From: "H. Nikolaus Schaller" hns@goldelico.com
mainline inclusion from mainline-5.8 commit 736bb11898ef748da1d805f40d485b66ceac9a3c category: bugfix bugzilla: 46847 CVE: NA
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strsep() is neither standard C nor POSIX and used outside the kernel code here. Using it here requires that the build host supports it out of the box which is e.g. not true for a Darwin build host and using a cross-compiler. This leads to:
scripts/mod/modpost.c:145:2: warning: implicit declaration of function 'strsep' [-Wimplicit-function-declaration] return strsep(stringp, "\n"); ^
and a segfault when running MODPOST.
See also: https://stackoverflow.com/a/7219504
So let's replace this by strchr() instead of using strsep(). It does not hurt kernel size or speed since this code is run on the build host.
Fixes: ac5100f5432967 ("modpost: add read_text_file() and get_line() helpers") Co-developed-by: Masahiro Yamada masahiroy@kernel.org Signed-off-by: H. Nikolaus Schaller hns@goldelico.com Signed-off-by: Masahiro Yamada masahiroy@kernel.org Signed-off-by: Wang Wensheng wangwensheng4@huawei.com Reviewed-by: Jian Cheng cj.chengjian@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- scripts/mod/modpost.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 99334521909b..b476d84feda7 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -160,11 +160,19 @@ char *read_text_file(const char *filename)
char *get_line(char **stringp) { + char *orig = *stringp, *next; + /* do not return the unwanted extra line at EOF */ - if (*stringp && **stringp == '\0') + if (!orig || *orig == '\0') return NULL;
- return strsep(stringp, "\n"); + next = strchr(orig, '\n'); + if (next) + *next++ = '\0'; + + *stringp = next; + + return orig; }
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