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authorLinus Torvalds <torvalds@linux-foundation.org>2020-01-27 10:54:24 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-01-27 10:54:24 -0800
commit715d1285695382b5074e49a0fe475b9ba56a1101 (patch)
tree9d79af4ac798bb93567ccfcbf66c2db6adca3791 /samples
parent12fb2b993e1508a0d9032a2314dfdda2a3a5535e (diff)
parentf46e49a9cc3814f3564477f0fffc00e0a2bc9e80 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching
Pull livepatching updates from Jiri Kosina: "Fixes for selftests and samples for 'shadow variables' livepatching feature, from Petr Mladek" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching: livepatch: Handle allocation failure in the sample of shadow variable API livepatch/samples/selftest: Use klp_shadow_alloc() API correctly livepatch/selftest: Clean up shadow variable names and type livepatch/sample: Use the right type for the leaking data pointer
Diffstat (limited to 'samples')
-rw-r--r--samples/livepatch/livepatch-shadow-fix1.c39
-rw-r--r--samples/livepatch/livepatch-shadow-fix2.c4
-rw-r--r--samples/livepatch/livepatch-shadow-mod.c4
3 files changed, 30 insertions, 17 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
diff --git a/samples/livepatch/livepatch-shadow-fix2.c b/samples/livepatch/livepatch-shadow-fix2.c
index 50d223b82e8b..29fe5cd42047 100644
--- a/samples/livepatch/livepatch-shadow-fix2.c
+++ b/samples/livepatch/livepatch-shadow-fix2.c
@@ -59,7 +59,7 @@ static bool livepatch_fix2_dummy_check(struct dummy *d, unsigned long jiffies)
static void livepatch_fix2_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",
@@ -68,7 +68,7 @@ static void livepatch_fix2_dummy_leak_dtor(void *obj, void *shadow_data)
static void livepatch_fix2_dummy_free(struct dummy *d)
{
- void **shadow_leak;
+ int **shadow_leak;
int *shadow_count;
/* Patch: copy the memory leak patch from the fix1 module. */
diff --git a/samples/livepatch/livepatch-shadow-mod.c b/samples/livepatch/livepatch-shadow-mod.c
index ecfe83a943a7..7e753b0d2fa6 100644
--- a/samples/livepatch/livepatch-shadow-mod.c
+++ b/samples/livepatch/livepatch-shadow-mod.c
@@ -95,7 +95,7 @@ struct dummy {
static __used noinline struct dummy *dummy_alloc(void)
{
struct dummy *d;
- void *leak;
+ int *leak;
d = kzalloc(sizeof(*d), GFP_KERNEL);
if (!d)
@@ -105,7 +105,7 @@ static __used noinline struct dummy *dummy_alloc(void)
msecs_to_jiffies(1000 * EXPIRE_PERIOD);
/* Oops, forgot to save leak! */
- leak = kzalloc(sizeof(int), GFP_KERNEL);
+ leak = kzalloc(sizeof(*leak), GFP_KERNEL);
if (!leak) {
kfree(d);
return NULL;