[PATCH] modpost: List all GPL-only symbols used by GPL-incompatible modules

From: Matthew Garrett
Date: Tue Jan 30 2018 - 14:01:47 EST


modpost currently exits after hitting the first GPL-only symbol used by
a GPL-incompatible module. Delay the failure until all symbols have been
processed in order to print all cases rather than just the first.

Signed-off-by: Matthew Garrett <mjg59@xxxxxxxxxx>
---
scripts/mod/modpost.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index f51cf977c65b..2daa66e4569c 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2056,29 +2056,30 @@ void buf_write(struct buffer *buf, const char *s, int len)
buf->pos += len;
}

-static void check_for_gpl_usage(enum export exp, const char *m, const char *s)
+static int check_for_gpl_usage(enum export exp, const char *m, const char *s)
{
const char *e = is_vmlinux(m) ?"":".ko";

switch (exp) {
case export_gpl:
- fatal("modpost: GPL-incompatible module %s%s "
+ warn("modpost: GPL-incompatible module %s%s "
"uses GPL-only symbol '%s'\n", m, e, s);
- break;
+ return 1;
case export_unused_gpl:
- fatal("modpost: GPL-incompatible module %s%s "
+ warn("modpost: GPL-incompatible module %s%s "
"uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
- break;
+ return 1;
case export_gpl_future:
warn("modpost: GPL-incompatible module %s%s "
"uses future GPL-only symbol '%s'\n", m, e, s);
- break;
+ return 0;
case export_plain:
case export_unused:
case export_unknown:
/* ignore */
- break;
+ return 0;
}
+ return 0;
}

static void check_for_unused(enum export exp, const char *m, const char *s)
@@ -2100,6 +2101,7 @@ static void check_for_unused(enum export exp, const char *m, const char *s)
static void check_exports(struct module *mod)
{
struct symbol *s, *exp;
+ int symbol_mismatch = 0;

for (s = mod->unres; s; s = s->next) {
const char *basename;
@@ -2111,10 +2113,13 @@ static void check_exports(struct module *mod)
basename++;
else
basename = mod->name;
- if (!mod->gpl_compatible)
- check_for_gpl_usage(exp->export, basename, exp->name);
+ if (!mod->gpl_compatible &&
+ check_for_gpl_usage(exp->export, basename, exp->name))
+ symbol_mismatch = 1;
check_for_unused(exp->export, basename, exp->name);
}
+ if (symbol_mismatch)
+ fatal("Module violates symbol usage policy\n");
}

static int check_modname_len(struct module *mod)
--
2.16.0.rc1.238.g530d649a79-goog