Commit 41e3bef5 authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching

Pull livepatching fix from Jiri Kosina:
 "Shadow variable API list_head initialization fix from Petr Mladek"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
  livepatch: Allow to call a custom callback when freeing shadow variables
  livepatch: Initialize shadow variables safely by a custom callback
parents 36e584de 3b2c77d0
...@@ -34,9 +34,13 @@ meta-data and shadow-data: ...@@ -34,9 +34,13 @@ meta-data and shadow-data:
- data[] - storage for shadow data - data[] - storage for shadow data
It is important to note that the klp_shadow_alloc() and It is important to note that the klp_shadow_alloc() and
klp_shadow_get_or_alloc() calls, described below, store a *copy* of the klp_shadow_get_or_alloc() are zeroing the variable by default.
data that the functions are provided. Callers should provide whatever They also allow to call a custom constructor function when a non-zero
mutual exclusion is required of the shadow data. value is needed. Callers should provide whatever mutual exclusion
is required.
Note that the constructor is called under klp_shadow_lock spinlock. It allows
to do actions that can be done only once when a new variable is allocated.
* klp_shadow_get() - retrieve a shadow variable data pointer * klp_shadow_get() - retrieve a shadow variable data pointer
- search hashtable for <obj, id> pair - search hashtable for <obj, id> pair
...@@ -47,7 +51,7 @@ mutual exclusion is required of the shadow data. ...@@ -47,7 +51,7 @@ mutual exclusion is required of the shadow data.
- WARN and return NULL - WARN and return NULL
- if <obj, id> doesn't already exist - if <obj, id> doesn't already exist
- allocate a new shadow variable - allocate a new shadow variable
- copy data into the new shadow variable - initialize the variable using a custom constructor and data when provided
- add <obj, id> to the global hashtable - add <obj, id> to the global hashtable
* klp_shadow_get_or_alloc() - get existing or alloc a new shadow variable * klp_shadow_get_or_alloc() - get existing or alloc a new shadow variable
...@@ -56,16 +60,20 @@ mutual exclusion is required of the shadow data. ...@@ -56,16 +60,20 @@ mutual exclusion is required of the shadow data.
- return existing shadow variable - return existing shadow variable
- if <obj, id> doesn't already exist - if <obj, id> doesn't already exist
- allocate a new shadow variable - allocate a new shadow variable
- copy data into the new shadow variable - initialize the variable using a custom constructor and data when provided
- add <obj, id> pair to the global hashtable - add <obj, id> pair to the global hashtable
* klp_shadow_free() - detach and free a <obj, id> shadow variable * klp_shadow_free() - detach and free a <obj, id> shadow variable
- find and remove a <obj, id> reference from global hashtable - find and remove a <obj, id> reference from global hashtable
- if found, free shadow variable - if found
- call destructor function if defined
- free shadow variable
* klp_shadow_free_all() - detach and free all <*, id> shadow variables * klp_shadow_free_all() - detach and free all <*, id> shadow variables
- find and remove any <*, id> references from global hashtable - find and remove any <*, id> references from global hashtable
- if found, free shadow variable - if found
- call destructor function if defined
- free shadow variable
2. Use cases 2. Use cases
...@@ -107,7 +115,8 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata, ...@@ -107,7 +115,8 @@ struct sta_info *sta_info_alloc(struct ieee80211_sub_if_data *sdata,
sta = kzalloc(sizeof(*sta) + hw->sta_data_size, gfp); sta = kzalloc(sizeof(*sta) + hw->sta_data_size, gfp);
/* Attach a corresponding shadow variable, then initialize it */ /* Attach a corresponding shadow variable, then initialize it */
ps_lock = klp_shadow_alloc(sta, PS_LOCK, NULL, sizeof(*ps_lock), gfp); ps_lock = klp_shadow_alloc(sta, PS_LOCK, sizeof(*ps_lock), gfp,
NULL, NULL);
if (!ps_lock) if (!ps_lock)
goto shadow_fail; goto shadow_fail;
spin_lock_init(ps_lock); spin_lock_init(ps_lock);
...@@ -131,7 +140,7 @@ variable: ...@@ -131,7 +140,7 @@ variable:
void sta_info_free(struct ieee80211_local *local, struct sta_info *sta) void sta_info_free(struct ieee80211_local *local, struct sta_info *sta)
{ {
klp_shadow_free(sta, PS_LOCK); klp_shadow_free(sta, PS_LOCK, NULL);
kfree(sta); kfree(sta);
... ...
...@@ -148,16 +157,24 @@ shadow variables to parents already in-flight. ...@@ -148,16 +157,24 @@ shadow variables to parents already in-flight.
For commit 1d147bfa6429, a good spot to allocate a shadow spinlock is For commit 1d147bfa6429, a good spot to allocate a shadow spinlock is
inside ieee80211_sta_ps_deliver_wakeup(): inside ieee80211_sta_ps_deliver_wakeup():
int ps_lock_shadow_ctor(void *obj, void *shadow_data, void *ctor_data)
{
spinlock_t *lock = shadow_data;
spin_lock_init(lock);
return 0;
}
#define PS_LOCK 1 #define PS_LOCK 1
void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta) void ieee80211_sta_ps_deliver_wakeup(struct sta_info *sta)
{ {
DEFINE_SPINLOCK(ps_lock_fallback);
spinlock_t *ps_lock; spinlock_t *ps_lock;
/* sync with ieee80211_tx_h_unicast_ps_buf */ /* sync with ieee80211_tx_h_unicast_ps_buf */
ps_lock = klp_shadow_get_or_alloc(sta, PS_LOCK, ps_lock = klp_shadow_get_or_alloc(sta, PS_LOCK,
&ps_lock_fallback, sizeof(ps_lock_fallback), sizeof(*ps_lock), GFP_ATOMIC,
GFP_ATOMIC); ps_lock_shadow_ctor, NULL);
if (ps_lock) if (ps_lock)
spin_lock(ps_lock); spin_lock(ps_lock);
... ...
......
...@@ -186,13 +186,20 @@ static inline bool klp_have_reliable_stack(void) ...@@ -186,13 +186,20 @@ static inline bool klp_have_reliable_stack(void)
IS_ENABLED(CONFIG_HAVE_RELIABLE_STACKTRACE); IS_ENABLED(CONFIG_HAVE_RELIABLE_STACKTRACE);
} }
typedef int (*klp_shadow_ctor_t)(void *obj,
void *shadow_data,
void *ctor_data);
typedef void (*klp_shadow_dtor_t)(void *obj, void *shadow_data);
void *klp_shadow_get(void *obj, unsigned long id); void *klp_shadow_get(void *obj, unsigned long id);
void *klp_shadow_alloc(void *obj, unsigned long id, void *data, void *klp_shadow_alloc(void *obj, unsigned long id,
size_t size, gfp_t gfp_flags); size_t size, gfp_t gfp_flags,
void *klp_shadow_get_or_alloc(void *obj, unsigned long id, void *data, klp_shadow_ctor_t ctor, void *ctor_data);
size_t size, gfp_t gfp_flags); void *klp_shadow_get_or_alloc(void *obj, unsigned long id,
void klp_shadow_free(void *obj, unsigned long id); size_t size, gfp_t gfp_flags,
void klp_shadow_free_all(unsigned long id); klp_shadow_ctor_t ctor, void *ctor_data);
void klp_shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor);
void klp_shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor);
#else /* !CONFIG_LIVEPATCH */ #else /* !CONFIG_LIVEPATCH */
......
...@@ -113,8 +113,10 @@ void *klp_shadow_get(void *obj, unsigned long id) ...@@ -113,8 +113,10 @@ void *klp_shadow_get(void *obj, unsigned long id)
} }
EXPORT_SYMBOL_GPL(klp_shadow_get); EXPORT_SYMBOL_GPL(klp_shadow_get);
static void *__klp_shadow_get_or_alloc(void *obj, unsigned long id, void *data, static void *__klp_shadow_get_or_alloc(void *obj, unsigned long id,
size_t size, gfp_t gfp_flags, bool warn_on_exist) size_t size, gfp_t gfp_flags,
klp_shadow_ctor_t ctor, void *ctor_data,
bool warn_on_exist)
{ {
struct klp_shadow *new_shadow; struct klp_shadow *new_shadow;
void *shadow_data; void *shadow_data;
...@@ -125,18 +127,15 @@ static void *__klp_shadow_get_or_alloc(void *obj, unsigned long id, void *data, ...@@ -125,18 +127,15 @@ static void *__klp_shadow_get_or_alloc(void *obj, unsigned long id, void *data,
if (shadow_data) if (shadow_data)
goto exists; goto exists;
/* Allocate a new shadow variable for use inside the lock below */ /*
* Allocate a new shadow variable. Fill it with zeroes by default.
* More complex setting can be done by @ctor function. But it is
* called only when the buffer is really used (under klp_shadow_lock).
*/
new_shadow = kzalloc(size + sizeof(*new_shadow), gfp_flags); new_shadow = kzalloc(size + sizeof(*new_shadow), gfp_flags);
if (!new_shadow) if (!new_shadow)
return NULL; return NULL;
new_shadow->obj = obj;
new_shadow->id = id;
/* Initialize the shadow variable if data provided */
if (data)
memcpy(new_shadow->data, data, size);
/* Look for <obj, id> again under the lock */ /* Look for <obj, id> again under the lock */
spin_lock_irqsave(&klp_shadow_lock, flags); spin_lock_irqsave(&klp_shadow_lock, flags);
shadow_data = klp_shadow_get(obj, id); shadow_data = klp_shadow_get(obj, id);
...@@ -150,6 +149,22 @@ static void *__klp_shadow_get_or_alloc(void *obj, unsigned long id, void *data, ...@@ -150,6 +149,22 @@ static void *__klp_shadow_get_or_alloc(void *obj, unsigned long id, void *data,
goto exists; goto exists;
} }
new_shadow->obj = obj;
new_shadow->id = id;
if (ctor) {
int err;
err = ctor(obj, new_shadow->data, ctor_data);
if (err) {
spin_unlock_irqrestore(&klp_shadow_lock, flags);
kfree(new_shadow);
pr_err("Failed to construct shadow variable <%p, %lx> (%d)\n",
obj, id, err);
return NULL;
}
}
/* No <obj, id> found, so attach the newly allocated one */ /* No <obj, id> found, so attach the newly allocated one */
hash_add_rcu(klp_shadow_hash, &new_shadow->node, hash_add_rcu(klp_shadow_hash, &new_shadow->node,
(unsigned long)new_shadow->obj); (unsigned long)new_shadow->obj);
...@@ -170,26 +185,32 @@ static void *__klp_shadow_get_or_alloc(void *obj, unsigned long id, void *data, ...@@ -170,26 +185,32 @@ static void *__klp_shadow_get_or_alloc(void *obj, unsigned long id, void *data,
* klp_shadow_alloc() - allocate and add a new shadow variable * klp_shadow_alloc() - allocate and add a new shadow variable
* @obj: pointer to parent object * @obj: pointer to parent object
* @id: data identifier * @id: data identifier
* @data: pointer to data to attach to parent
* @size: size of attached data * @size: size of attached data
* @gfp_flags: GFP mask for allocation * @gfp_flags: GFP mask for allocation
* @ctor: custom constructor to initialize the shadow data (optional)
* @ctor_data: pointer to any data needed by @ctor (optional)
* *
* Allocates @size bytes for new shadow variable data using @gfp_flags * Allocates @size bytes for new shadow variable data using @gfp_flags.
* and copies @size bytes from @data into the new shadow variable's own * The data are zeroed by default. They are further initialized by @ctor
* data space. If @data is NULL, @size bytes are still allocated, but * function if it is not NULL. The new shadow variable is then added
* no copy is performed. The new shadow variable is then added to the * to the global hashtable.
* global hashtable.
* *
* If an existing <obj, id> shadow variable can be found, this routine * If an existing <obj, id> shadow variable can be found, this routine will
* will issue a WARN, exit early and return NULL. * issue a WARN, exit early and return NULL.
*
* This function guarantees that the constructor function is called only when
* the variable did not exist before. The cost is that @ctor is called
* in atomic context under a spin lock.
* *
* Return: the shadow variable data element, NULL on duplicate or * Return: the shadow variable data element, NULL on duplicate or
* failure. * failure.
*/ */
void *klp_shadow_alloc(void *obj, unsigned long id, void *data, void *klp_shadow_alloc(void *obj, unsigned long id,
size_t size, gfp_t gfp_flags) size_t size, gfp_t gfp_flags,
klp_shadow_ctor_t ctor, void *ctor_data)
{ {
return __klp_shadow_get_or_alloc(obj, id, data, size, gfp_flags, true); return __klp_shadow_get_or_alloc(obj, id, size, gfp_flags,
ctor, ctor_data, true);
} }
EXPORT_SYMBOL_GPL(klp_shadow_alloc); EXPORT_SYMBOL_GPL(klp_shadow_alloc);
...@@ -197,37 +218,51 @@ EXPORT_SYMBOL_GPL(klp_shadow_alloc); ...@@ -197,37 +218,51 @@ EXPORT_SYMBOL_GPL(klp_shadow_alloc);
* klp_shadow_get_or_alloc() - get existing or allocate a new shadow variable * klp_shadow_get_or_alloc() - get existing or allocate a new shadow variable
* @obj: pointer to parent object * @obj: pointer to parent object
* @id: data identifier * @id: data identifier
* @data: pointer to data to attach to parent
* @size: size of attached data * @size: size of attached data
* @gfp_flags: GFP mask for allocation * @gfp_flags: GFP mask for allocation
* @ctor: custom constructor to initialize the shadow data (optional)
* @ctor_data: pointer to any data needed by @ctor (optional)
* *
* Returns a pointer to existing shadow data if an <obj, id> shadow * Returns a pointer to existing shadow data if an <obj, id> shadow
* variable is already present. Otherwise, it creates a new shadow * variable is already present. Otherwise, it creates a new shadow
* variable like klp_shadow_alloc(). * variable like klp_shadow_alloc().
* *
* This function guarantees that only one shadow variable exists with * This function guarantees that only one shadow variable exists with the given
* the given @id for the given @obj. It also guarantees that the shadow * @id for the given @obj. It also guarantees that the constructor function
* variable will be initialized by the given @data only when it did not * will be called only when the variable did not exist before. The cost is
* exist before. * that @ctor is called in atomic context under a spin lock.
* *
* Return: the shadow variable data element, NULL on failure. * Return: the shadow variable data element, NULL on failure.
*/ */
void *klp_shadow_get_or_alloc(void *obj, unsigned long id, void *data, void *klp_shadow_get_or_alloc(void *obj, unsigned long id,
size_t size, gfp_t gfp_flags) size_t size, gfp_t gfp_flags,
klp_shadow_ctor_t ctor, void *ctor_data)
{ {
return __klp_shadow_get_or_alloc(obj, id, data, size, gfp_flags, false); return __klp_shadow_get_or_alloc(obj, id, size, gfp_flags,
ctor, ctor_data, false);
} }
EXPORT_SYMBOL_GPL(klp_shadow_get_or_alloc); EXPORT_SYMBOL_GPL(klp_shadow_get_or_alloc);
static void klp_shadow_free_struct(struct klp_shadow *shadow,
klp_shadow_dtor_t dtor)
{
hash_del_rcu(&shadow->node);
if (dtor)
dtor(shadow->obj, shadow->data);
kfree_rcu(shadow, rcu_head);
}
/** /**
* klp_shadow_free() - detach and free a <obj, id> shadow variable * klp_shadow_free() - detach and free a <obj, id> shadow variable
* @obj: pointer to parent object * @obj: pointer to parent object
* @id: data identifier * @id: data identifier
* @dtor: custom callback that can be used to unregister the variable
* and/or free data that the shadow variable points to (optional)
* *
* This function releases the memory for this <obj, id> shadow variable * This function releases the memory for this <obj, id> shadow variable
* instance, callers should stop referencing it accordingly. * instance, callers should stop referencing it accordingly.
*/ */
void klp_shadow_free(void *obj, unsigned long id) void klp_shadow_free(void *obj, unsigned long id, klp_shadow_dtor_t dtor)
{ {
struct klp_shadow *shadow; struct klp_shadow *shadow;
unsigned long flags; unsigned long flags;
...@@ -239,8 +274,7 @@ void klp_shadow_free(void *obj, unsigned long id) ...@@ -239,8 +274,7 @@ void klp_shadow_free(void *obj, unsigned long id)
(unsigned long)obj) { (unsigned long)obj) {
if (klp_shadow_match(shadow, obj, id)) { if (klp_shadow_match(shadow, obj, id)) {
hash_del_rcu(&shadow->node); klp_shadow_free_struct(shadow, dtor);
kfree_rcu(shadow, rcu_head);
break; break;
} }
} }
...@@ -252,11 +286,13 @@ EXPORT_SYMBOL_GPL(klp_shadow_free); ...@@ -252,11 +286,13 @@ EXPORT_SYMBOL_GPL(klp_shadow_free);
/** /**
* klp_shadow_free_all() - detach and free all <*, id> shadow variables * klp_shadow_free_all() - detach and free all <*, id> shadow variables
* @id: data identifier * @id: data identifier
* @dtor: custom callback that can be used to unregister the variable
* and/or free data that the shadow variable points to (optional)
* *
* This function releases the memory for all <*, id> shadow variable * This function releases the memory for all <*, id> shadow variable
* instances, callers should stop referencing them accordingly. * instances, callers should stop referencing them accordingly.
*/ */
void klp_shadow_free_all(unsigned long id) void klp_shadow_free_all(unsigned long id, klp_shadow_dtor_t dtor)
{ {
struct klp_shadow *shadow; struct klp_shadow *shadow;
unsigned long flags; unsigned long flags;
...@@ -266,10 +302,8 @@ void klp_shadow_free_all(unsigned long id) ...@@ -266,10 +302,8 @@ void klp_shadow_free_all(unsigned long id)
/* Delete all <*, id> from hash */ /* Delete all <*, id> from hash */
hash_for_each(klp_shadow_hash, i, shadow, node) { hash_for_each(klp_shadow_hash, i, shadow, node) {
if (klp_shadow_match(shadow, shadow->obj, id)) { if (klp_shadow_match(shadow, shadow->obj, id))
hash_del_rcu(&shadow->node); klp_shadow_free_struct(shadow, dtor);
kfree_rcu(shadow, rcu_head);
}
} }
spin_unlock_irqrestore(&klp_shadow_lock, flags); spin_unlock_irqrestore(&klp_shadow_lock, flags);
......
...@@ -56,6 +56,21 @@ struct dummy { ...@@ -56,6 +56,21 @@ struct dummy {
unsigned long jiffies_expire; unsigned long jiffies_expire;
}; };
/*
* The constructor makes more sense together with klp_shadow_get_or_alloc().
* In this example, it would be safe to assign the pointer also to the shadow
* variable returned by klp_shadow_alloc(). But we wanted to show the more
* complicated use of the API.
*/
static int shadow_leak_ctor(void *obj, void *shadow_data, void *ctor_data)
{
void **shadow_leak = shadow_data;
void *leak = ctor_data;
*shadow_leak = leak;
return 0;
}
struct dummy *livepatch_fix1_dummy_alloc(void) struct dummy *livepatch_fix1_dummy_alloc(void)
{ {
struct dummy *d; struct dummy *d;
...@@ -74,7 +89,8 @@ struct dummy *livepatch_fix1_dummy_alloc(void) ...@@ -74,7 +89,8 @@ struct dummy *livepatch_fix1_dummy_alloc(void)
* pointer to handle resource release. * pointer to handle resource release.
*/ */
leak = kzalloc(sizeof(int), GFP_KERNEL); leak = kzalloc(sizeof(int), GFP_KERNEL);
klp_shadow_alloc(d, SV_LEAK, &leak, sizeof(leak), GFP_KERNEL); klp_shadow_alloc(d, SV_LEAK, sizeof(leak), GFP_KERNEL,
shadow_leak_ctor, leak);
pr_info("%s: dummy @ %p, expires @ %lx\n", pr_info("%s: dummy @ %p, expires @ %lx\n",
__func__, d, d->jiffies_expire); __func__, d, d->jiffies_expire);
...@@ -82,9 +98,19 @@ struct dummy *livepatch_fix1_dummy_alloc(void) ...@@ -82,9 +98,19 @@ struct dummy *livepatch_fix1_dummy_alloc(void)
return d; return d;
} }
static void livepatch_fix1_dummy_leak_dtor(void *obj, void *shadow_data)
{
void *d = obj;
void **shadow_leak = shadow_data;
kfree(*shadow_leak);
pr_info("%s: dummy @ %p, prevented leak @ %p\n",
__func__, d, *shadow_leak);
}
void livepatch_fix1_dummy_free(struct dummy *d) void livepatch_fix1_dummy_free(struct dummy *d)
{ {
void **shadow_leak, *leak; void **shadow_leak;
/* /*
* Patch: fetch the saved SV_LEAK shadow variable, detach and * Patch: fetch the saved SV_LEAK shadow variable, detach and
...@@ -93,15 +119,10 @@ void livepatch_fix1_dummy_free(struct dummy *d) ...@@ -93,15 +119,10 @@ void livepatch_fix1_dummy_free(struct dummy *d)
* was loaded.) * was loaded.)
*/ */
shadow_leak = klp_shadow_get(d, SV_LEAK); shadow_leak = klp_shadow_get(d, SV_LEAK);
if (shadow_leak) { if (shadow_leak)
leak = *shadow_leak; klp_shadow_free(d, SV_LEAK, livepatch_fix1_dummy_leak_dtor);
klp_shadow_free(d, SV_LEAK); else
kfree(leak);
pr_info("%s: dummy @ %p, prevented leak @ %p\n",
__func__, d, leak);
} else {
pr_info("%s: dummy @ %p leaked!\n", __func__, d); pr_info("%s: dummy @ %p leaked!\n", __func__, d);
}
kfree(d); kfree(d);
} }
...@@ -147,7 +168,7 @@ static int livepatch_shadow_fix1_init(void) ...@@ -147,7 +168,7 @@ static int livepatch_shadow_fix1_init(void)
static void livepatch_shadow_fix1_exit(void) static void livepatch_shadow_fix1_exit(void)
{ {
/* Cleanup any existing SV_LEAK shadow variables */ /* Cleanup any existing SV_LEAK shadow variables */
klp_shadow_free_all(SV_LEAK); klp_shadow_free_all(SV_LEAK, livepatch_fix1_dummy_leak_dtor);
WARN_ON(klp_unregister_patch(&patch)); WARN_ON(klp_unregister_patch(&patch));
} }
......
...@@ -53,39 +53,42 @@ struct dummy { ...@@ -53,39 +53,42 @@ struct dummy {
bool livepatch_fix2_dummy_check(struct dummy *d, unsigned long jiffies) bool livepatch_fix2_dummy_check(struct dummy *d, unsigned long jiffies)
{ {
int *shadow_count; int *shadow_count;
int count;
/* /*
* Patch: handle in-flight dummy structures, if they do not * Patch: handle in-flight dummy structures, if they do not
* already have a SV_COUNTER shadow variable, then attach a * already have a SV_COUNTER shadow variable, then attach a
* new one. * new one.
*/ */
count = 0;
shadow_count = klp_shadow_get_or_alloc(d, SV_COUNTER, shadow_count = klp_shadow_get_or_alloc(d, SV_COUNTER,
&count, sizeof(count), sizeof(*shadow_count), GFP_NOWAIT,
GFP_NOWAIT); NULL, NULL);
if (shadow_count) if (shadow_count)
*shadow_count += 1; *shadow_count += 1;
return time_after(jiffies, d->jiffies_expire); return time_after(jiffies, d->jiffies_expire);
} }
static void livepatch_fix2_dummy_leak_dtor(void *obj, void *shadow_data)
{
void *d = obj;
void **shadow_leak = shadow_data;
kfree(*shadow_leak);
pr_info("%s: dummy @ %p, prevented leak @ %p\n",
__func__, d, *shadow_leak);
}
void livepatch_fix2_dummy_free(struct dummy *d) void livepatch_fix2_dummy_free(struct dummy *d)
{ {
void **shadow_leak, *leak; void **shadow_leak;
int *shadow_count; int *shadow_count;
/* Patch: copy the memory leak patch from the fix1 module. */ /* Patch: copy the memory leak patch from the fix1 module. */
shadow_leak = klp_shadow_get(d, SV_LEAK); shadow_leak = klp_shadow_get(d, SV_LEAK);
if (shadow_leak) { if (shadow_leak)
leak = *shadow_leak; klp_shadow_free(d, SV_LEAK, livepatch_fix2_dummy_leak_dtor);
klp_shadow_free(d, SV_LEAK); else
kfree(leak);
pr_info("%s: dummy @ %p, prevented leak @ %p\n",
__func__, d, leak);
} else {
pr_info("%s: dummy @ %p leaked!\n", __func__, d); pr_info("%s: dummy @ %p leaked!\n", __func__, d);
}
/* /*
* Patch: fetch the SV_COUNTER shadow variable and display * Patch: fetch the SV_COUNTER shadow variable and display
...@@ -95,7 +98,7 @@ void livepatch_fix2_dummy_free(struct dummy *d) ...@@ -95,7 +98,7 @@ void livepatch_fix2_dummy_free(struct dummy *d)
if (shadow_count) { if (shadow_count) {
pr_info("%s: dummy @ %p, check counter = %d\n", pr_info("%s: dummy @ %p, check counter = %d\n",
__func__, d, *shadow_count); __func__, d, *shadow_count);
klp_shadow_free(d, SV_COUNTER); klp_shadow_free(d, SV_COUNTER, NULL);
} }
kfree(d); kfree(d);
...@@ -142,7 +145,7 @@ static int livepatch_shadow_fix2_init(void) ...@@ -142,7 +145,7 @@ static int livepatch_shadow_fix2_init(void)
static void livepatch_shadow_fix2_exit(void) static void livepatch_shadow_fix2_exit(void)
{ {
/* Cleanup any existing SV_COUNTER shadow variables */ /* Cleanup any existing SV_COUNTER shadow variables */
klp_shadow_free_all(SV_COUNTER); klp_shadow_free_all(SV_COUNTER, NULL);
WARN_ON(klp_unregister_patch(&patch)); WARN_ON(klp_unregister_patch(&patch));
} }
......
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