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Diffstat (limited to 'samples/livepatch/livepatch-shadow-fix1.c')
-rw-r--r--samples/livepatch/livepatch-shadow-fix1.c39
1 files changed, 26 insertions, 13 deletions
diff --git a/samples/livepatch/livepatch-shadow-fix1.c b/samples/livepatch/livepatch-shadow-fix1.c
index e89ca4546114..918ce17b43fd 100644
--- a/samples/livepatch/livepatch-shadow-fix1.c
+++ b/samples/livepatch/livepatch-shadow-fix1.c
@@ -52,17 +52,21 @@ struct dummy {
*/
static int shadow_leak_ctor(void *obj, void *shadow_data, void *ctor_data)
{
- void **shadow_leak = shadow_data;
- void *leak = ctor_data;
+ int **shadow_leak = shadow_data;
+ int **leak = ctor_data;
- *shadow_leak = leak;
+ if (!ctor_data)
+ return -EINVAL;
+
+ *shadow_leak = *leak;
return 0;
}
static struct dummy *livepatch_fix1_dummy_alloc(void)
{
struct dummy *d;
- void *leak;
+ int *leak;
+ int **shadow_leak;
d = kzalloc(sizeof(*d), GFP_KERNEL);
if (!d)
@@ -76,25 +80,34 @@ static struct dummy *livepatch_fix1_dummy_alloc(void)
* variable. A patched dummy_free routine can later fetch this
* pointer to handle resource release.
*/
- leak = kzalloc(sizeof(int), GFP_KERNEL);
- if (!leak) {
- kfree(d);
- return NULL;
+ leak = kzalloc(sizeof(*leak), GFP_KERNEL);
+ if (!leak)
+ goto err_leak;
+
+ shadow_leak = klp_shadow_alloc(d, SV_LEAK, sizeof(leak), GFP_KERNEL,
+ shadow_leak_ctor, &leak);
+ if (!shadow_leak) {
+ pr_err("%s: failed to allocate shadow variable for the leaking pointer: dummy @ %p, leak @ %p\n",
+ __func__, d, leak);
+ goto err_shadow;
}
- klp_shadow_alloc(d, SV_LEAK, sizeof(leak), GFP_KERNEL,
- shadow_leak_ctor, leak);
-
pr_info("%s: dummy @ %p, expires @ %lx\n",
__func__, d, d->jiffies_expire);
return d;
+
+err_shadow:
+ kfree(leak);
+err_leak:
+ kfree(d);
+ return NULL;
}
static void livepatch_fix1_dummy_leak_dtor(void *obj, void *shadow_data)
{
void *d = obj;
- void **shadow_leak = shadow_data;
+ int **shadow_leak = shadow_data;
kfree(*shadow_leak);
pr_info("%s: dummy @ %p, prevented leak @ %p\n",
@@ -103,7 +116,7 @@ static void livepatch_fix1_dummy_leak_dtor(void *obj, void *shadow_data)
static void livepatch_fix1_dummy_free(struct dummy *d)
{
- void **shadow_leak;
+ int **shadow_leak;
/*
* Patch: fetch the saved SV_LEAK shadow variable, detach and