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kbuild: warn when a moduled uses a symbol marked UNUSED

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We now have infrastructure in place to mark an EXPORTed symbol
as unused. So the natural next step is to warn during buildtime when
a module uses a symbol marked UNUSED.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
This commit is contained in:
Sam Ravnborg 2006-07-01 11:44:23 +02:00
parent 534b89a9f6
commit c96fca2137
2 changed files with 64 additions and 23 deletions
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85
scripts/mod/modpost.c
View file

@ -24,7 +24,10 @@ static int all_versions = 0;
/* If we are modposting external module set to 1 */
static int external_module = 0;
/* How a symbol is exported */
enum export {export_plain, export_gpl, export_gpl_future, export_unknown};
enum export {
export_plain, export_unused, export_gpl,
export_unused_gpl, export_gpl_future, export_unknown
};
void fatal(const char *fmt, ...)
{
@ -191,7 +194,9 @@ static struct {
enum export export;
} export_list[] = {
{ .str = "EXPORT_SYMBOL", .export = export_plain },
{ .str = "EXPORT_UNUSED_SYMBOL", .export = export_unused },
{ .str = "EXPORT_SYMBOL_GPL", .export = export_gpl },
{ .str = "EXPORT_UNUSED_SYMBOL_GPL", .export = export_unused_gpl },
{ .str = "EXPORT_SYMBOL_GPL_FUTURE", .export = export_gpl_future },
{ .str = "(unknown)", .export = export_unknown },
};
@ -218,8 +223,12 @@ static enum export export_from_sec(struct elf_info *elf, Elf_Section sec)
{
if (sec == elf->export_sec)
return export_plain;
else if (sec == elf->export_unused_sec)
return export_unused;
else if (sec == elf->export_gpl_sec)
return export_gpl;
else if (sec == elf->export_unused_gpl_sec)
return export_unused_gpl;
else if (sec == elf->export_gpl_future_sec)
return export_gpl_future;
else
@ -368,8 +377,12 @@ static void parse_elf(struct elf_info *info, const char *filename)
info->modinfo_len = sechdrs[i].sh_size;
} else if (strcmp(secname, "__ksymtab") == 0)
info->export_sec = i;
else if (strcmp(secname, "__ksymtab_unused") == 0)
info->export_unused_sec = i;
else if (strcmp(secname, "__ksymtab_gpl") == 0)
info->export_gpl_sec = i;
else if (strcmp(secname, "__ksymtab_unused_gpl") == 0)
info->export_unused_gpl_sec = i;
else if (strcmp(secname, "__ksymtab_gpl_future") == 0)
info->export_gpl_future_sec = i;
@ -1087,38 +1100,64 @@ void buf_write(struct buffer *buf, const char *s, int len)
buf->pos += len;
}
void check_license(struct module *mod)
static void 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 "
"uses GPL-only symbol '%s'\n", m, e, s);
break;
case export_unused_gpl:
fatal("modpost: GPL-incompatible module %s%s "
"uses GPL-only symbol marked UNUSED '%s'\n", m, e, s);
break;
case export_gpl_future:
warn("modpost: GPL-incompatible module %s%s "
"uses future GPL-only symbol '%s'\n", m, e, s);
break;
case export_plain:
case export_unused:
case export_unknown:
/* ignore */
break;
}
}
static void check_for_unused(enum export exp, const char* m, const char* s)
{
const char *e = is_vmlinux(m) ?"":".ko";
switch (exp) {
case export_unused:
case export_unused_gpl:
warn("modpost: module %s%s "
"uses symbol '%s' marked UNUSED\n", m, e, s);
break;
default:
/* ignore */
break;
}
}
static void check_exports(struct module *mod)
{
struct symbol *s, *exp;
for (s = mod->unres; s; s = s->next) {
const char *basename;
if (mod->gpl_compatible == 1) {
/* GPL-compatible modules may use all symbols */
continue;
}
exp = find_symbol(s->name);
if (!exp || exp->module == mod)
continue;
basename = strrchr(mod->name, '/');
if (basename)
basename++;
switch (exp->export) {
case export_gpl:
fatal("modpost: GPL-incompatible module %s "
"uses GPL-only symbol '%s'\n",
basename ? basename : mod->name,
exp->name);
break;
case export_gpl_future:
warn("modpost: GPL-incompatible module %s "
"uses future GPL-only symbol '%s'\n",
basename ? basename : mod->name,
exp->name);
break;
case export_plain: /* ignore */ break;
case export_unknown: /* ignore */ break;
}
else
basename = mod->name;
if (!mod->gpl_compatible)
check_for_gpl_usage(exp->export, basename, exp->name);
check_for_unused(exp->export, basename, exp->name);
}
}
@ -1399,7 +1438,7 @@ int main(int argc, char **argv)
for (mod = modules; mod; mod = mod->next) {
if (mod->skip)
continue;
check_license(mod);
check_exports(mod);
}
for (mod = modules; mod; mod = mod->next) {

2
scripts/mod/modpost.h
View file

@ -117,7 +117,9 @@ struct elf_info {
Elf_Sym *symtab_start;
Elf_Sym *symtab_stop;
Elf_Section export_sec;
Elf_Section export_unused_sec;
Elf_Section export_gpl_sec;
Elf_Section export_unused_gpl_sec;
Elf_Section export_gpl_future_sec;
const char *strtab;
char *modinfo;