| Message ID | 60381408622ebbb7d205b2cf6edcf8c6acecf1d7.1593584306.git.hns@goldelico.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] modpost: remove use of non-standard strsep() in HOSTCC code | expand |
On Wed, Jul 1, 2020 at 3:18 PM H. Nikolaus Schaller <hns@goldelico.com> wrote: > > 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> > --- Applied to linux-kbuild. Thanks. > 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 6aea65c657454..45f2ab2ec2d46 100644 > --- a/scripts/mod/modpost.c > +++ b/scripts/mod/modpost.c > @@ -138,11 +138,19 @@ 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; > } > > /* A list of all modules we processed */ > -- > 2.26.2 >
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 6aea65c657454..45f2ab2ec2d46 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -138,11 +138,19 @@ 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; } /* A list of all modules we processed */
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> --- scripts/mod/modpost.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)