diff options
Diffstat (limited to 'samples/livepatch/livepatch-shadow-fix1.c')
| -rw-r--r-- | samples/livepatch/livepatch-shadow-fix1.c | 39 |
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 |