[PATCH 7/8] modules: return licensing information from find_symbol

From: Christoph Hellwig
Date: Thu Jul 30 2020 - 02:10:56 EST


Report the GPLONLY status through a new argument.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
include/linux/module.h | 2 +-
kernel/module.c | 16 +++++++++++-----
2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/include/linux/module.h b/include/linux/module.h
index be04ba2f881daa..30b0f5fcdb3c37 100644
--- a/include/linux/module.h
+++ b/include/linux/module.h
@@ -582,7 +582,7 @@ struct module *find_module(const char *name);
struct symsearch {
const struct kernel_symbol *start, *stop;
const s32 *crcs;
- enum {
+ enum mod_license {
NOT_GPL_ONLY,
GPL_ONLY,
WILL_BE_GPL_ONLY,
diff --git a/kernel/module.c b/kernel/module.c
index a0df783a8a6e5b..afb2bfdd5134b3 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -495,6 +495,7 @@ struct find_symbol_arg {
struct module *owner;
const s32 *crc;
const struct kernel_symbol *sym;
+ enum mod_license license;
};

static bool check_exported_symbol(const struct symsearch *syms,
@@ -528,6 +529,7 @@ static bool check_exported_symbol(const struct symsearch *syms,
fsa->owner = owner;
fsa->crc = symversion(syms->crcs, symnum);
fsa->sym = &syms->start[symnum];
+ fsa->license = syms->license;
return true;
}

@@ -587,6 +589,7 @@ static bool find_exported_symbol_in_section(const struct symsearch *syms,
static const struct kernel_symbol *find_symbol(const char *name,
struct module **owner,
const s32 **crc,
+ enum mod_license *license,
bool gplok,
bool warn)
{
@@ -601,6 +604,8 @@ static const struct kernel_symbol *find_symbol(const char *name,
*owner = fsa.owner;
if (crc)
*crc = fsa.crc;
+ if (license)
+ *license = fsa.license;
return fsa.sym;
}

@@ -1074,7 +1079,7 @@ void __symbol_put(const char *symbol)
struct module *owner;

preempt_disable();
- if (!find_symbol(symbol, &owner, NULL, true, false))
+ if (!find_symbol(symbol, &owner, NULL, NULL, true, false))
BUG();
module_put(owner);
preempt_enable();
@@ -1352,7 +1357,7 @@ static inline int check_modstruct_version(const struct load_info *info,
* locking is necessary -- use preempt_disable() to placate lockdep.
*/
preempt_disable();
- if (!find_symbol("module_layout", NULL, &crc, true, false)) {
+ if (!find_symbol("module_layout", NULL, &crc, NULL, true, false)) {
preempt_enable();
BUG();
}
@@ -1436,6 +1441,7 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod,
struct module *owner;
const struct kernel_symbol *sym;
const s32 *crc;
+ enum mod_license license;
int err;

/*
@@ -1445,7 +1451,7 @@ static const struct kernel_symbol *resolve_symbol(struct module *mod,
*/
sched_annotate_sleep();
mutex_lock(&module_mutex);
- sym = find_symbol(name, &owner, &crc,
+ sym = find_symbol(name, &owner, &crc, &license,
!(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
if (!sym)
goto unlock;
@@ -2216,7 +2222,7 @@ void *__symbol_get(const char *symbol)
const struct kernel_symbol *sym;

preempt_disable();
- sym = find_symbol(symbol, &owner, NULL, true, true);
+ sym = find_symbol(symbol, &owner, NULL, NULL, true, true);
if (sym && strong_try_module_get(owner))
sym = NULL;
preempt_enable();
@@ -2252,7 +2258,7 @@ static int verify_exported_symbols(struct module *mod)
for (i = 0; i < ARRAY_SIZE(arr); i++) {
for (s = arr[i].sym; s < arr[i].sym + arr[i].num; s++) {
if (find_symbol(kernel_symbol_name(s), &owner, NULL,
- true, false)) {
+ NULL, true, false)) {
pr_err("%s: exports duplicate symbol %s"
" (owned by %s)\n",
mod->name, kernel_symbol_name(s),
--
2.27.0