ANDROID: security: selinux: Add restricted vendor hook in avc

Add restricted vendor hook for avc, so we can get avc_node
information to monitor avc lifetime.

Bug: 181639260

Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Change-Id: Idbebeca926c2cb407264f2872b032e1f18462697
This commit is contained in:
Kuan-Ying Lee
2021-10-05 17:07:57 +08:00
parent 64eaf18f7f
commit 6605f296d3
3 changed files with 47 additions and 1 deletions

View File

@@ -37,6 +37,7 @@
#include <trace/hooks/pm_domain.h>
#include <trace/hooks/cpuidle_psci.h>
#include <trace/hooks/vmscan.h>
#include <trace/hooks/avc.h>
/*
* Export tracepoints that act as a bare tracehook (ie: have no trace event
@@ -174,3 +175,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_dequeue_entity);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_entity_tick);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_enqueue_task_fair);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_dequeue_task_fair);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_selinux_avc_insert);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_selinux_avc_node_delete);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_selinux_avc_node_replace);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_selinux_avc_lookup);

33
include/trace/hooks/avc.h Normal file
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@@ -0,0 +1,33 @@
/* SPDX-License-Identifier: GPL-2.0 */
#undef TRACE_SYSTEM
#define TRACE_SYSTEM avc
#define TRACE_INCLUDE_PATH trace/hooks
#if !defined(_TRACE_HOOK_AVC_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_HOOK_AVC_H
#include <linux/tracepoint.h>
#include <trace/hooks/vendor_hooks.h>
/*
* Following tracepoints are not exported in tracefs and provide a
* mechanism for vendor modules to hook and extend functionality
*/
struct avc_node;
DECLARE_RESTRICTED_HOOK(android_rvh_selinux_avc_insert,
TP_PROTO(const struct avc_node *node),
TP_ARGS(node), 1);
DECLARE_RESTRICTED_HOOK(android_rvh_selinux_avc_node_delete,
TP_PROTO(const struct avc_node *node),
TP_ARGS(node), 1);
DECLARE_RESTRICTED_HOOK(android_rvh_selinux_avc_node_replace,
TP_PROTO(const struct avc_node *old, const struct avc_node *new),
TP_ARGS(old, new), 1);
DECLARE_RESTRICTED_HOOK(android_rvh_selinux_avc_lookup,
TP_PROTO(const struct avc_node *node, u32 ssid, u32 tsid, u16 tclass),
TP_ARGS(node, ssid, tsid, tclass), 1);
#endif /* _TRACE_HOOK_AVC_H */
/* This part must be outside protection */
#include <trace/define_trace.h>

View File

@@ -44,6 +44,9 @@
#define avc_cache_stats_incr(field) do {} while (0)
#endif
#undef CREATE_TRACE_POINTS
#include <trace/hooks/avc.h>
struct avc_entry {
u32 ssid;
u32 tsid;
@@ -441,6 +444,7 @@ static void avc_node_free(struct rcu_head *rhead)
static void avc_node_delete(struct selinux_avc *avc, struct avc_node *node)
{
trace_android_rvh_selinux_avc_node_delete(node);
hlist_del_rcu(&node->list);
call_rcu(&node->rhead, avc_node_free);
atomic_dec(&avc->avc_cache.active_nodes);
@@ -457,6 +461,7 @@ static void avc_node_kill(struct selinux_avc *avc, struct avc_node *node)
static void avc_node_replace(struct selinux_avc *avc,
struct avc_node *new, struct avc_node *old)
{
trace_android_rvh_selinux_avc_node_replace(old, new);
hlist_replace_rcu(&old->list, &new->list);
call_rcu(&old->rhead, avc_node_free);
atomic_dec(&avc->avc_cache.active_nodes);
@@ -565,8 +570,10 @@ static struct avc_node *avc_lookup(struct selinux_avc *avc,
avc_cache_stats_incr(lookups);
node = avc_search_node(avc, ssid, tsid, tclass);
if (node)
if (node) {
trace_android_rvh_selinux_avc_lookup(node, ssid, tsid, tclass);
return node;
}
avc_cache_stats_incr(misses);
return NULL;
@@ -650,6 +657,7 @@ static struct avc_node *avc_insert(struct selinux_avc *avc,
}
}
hlist_add_head_rcu(&node->list, head);
trace_android_rvh_selinux_avc_insert(node);
found:
spin_unlock_irqrestore(lock, flag);
return node;