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-rw-r--r--security/selinux/ss/Makefile2
-rw-r--r--security/selinux/ss/services.c3
-rw-r--r--security/selinux/ss/status.c129
3 files changed, 133 insertions, 1 deletions
diff --git a/security/selinux/ss/Makefile b/security/selinux/ss/Makefile
index 15d4e62917d..974e11c7cf5 100644
--- a/security/selinux/ss/Makefile
+++ b/security/selinux/ss/Makefile
@@ -5,5 +5,5 @@
EXTRA_CFLAGS += -Isecurity/selinux -Isecurity/selinux/include
obj-y := ss.o
-ss-y := ebitmap.o hashtab.o symtab.o sidtab.o avtab.o policydb.o services.o conditional.o mls.o
+ss-y := ebitmap.o hashtab.o symtab.o sidtab.o avtab.o policydb.o services.o conditional.o mls.o status.o
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 9ea2feca3cd..494ff527c17 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -1791,6 +1791,7 @@ int security_load_policy(void *data, size_t len)
selinux_complete_init();
avc_ss_reset(seqno);
selnl_notify_policyload(seqno);
+ selinux_status_update_policyload(seqno);
selinux_netlbl_cache_invalidate();
selinux_xfrm_notify_policyload();
return 0;
@@ -1870,6 +1871,7 @@ int security_load_policy(void *data, size_t len)
avc_ss_reset(seqno);
selnl_notify_policyload(seqno);
+ selinux_status_update_policyload(seqno);
selinux_netlbl_cache_invalidate();
selinux_xfrm_notify_policyload();
@@ -2374,6 +2376,7 @@ out:
if (!rc) {
avc_ss_reset(seqno);
selnl_notify_policyload(seqno);
+ selinux_status_update_policyload(seqno);
selinux_xfrm_notify_policyload();
}
return rc;
diff --git a/security/selinux/ss/status.c b/security/selinux/ss/status.c
new file mode 100644
index 00000000000..5d9b225f856
--- /dev/null
+++ b/security/selinux/ss/status.c
@@ -0,0 +1,129 @@
+/*
+ * mmap based event notifications for SELinux
+ *
+ * Author: KaiGai Kohei <kaigai@ak.jp.nec.com>
+ *
+ * Copyright (C) 2010 NEC corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2,
+ * as published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/gfp.h>
+#include <linux/mm.h>
+#include <linux/mutex.h>
+#include "avc.h"
+#include "services.h"
+
+/*
+ * The selinux_status_page shall be exposed to userspace applications
+ * using mmap interface on /selinux/status.
+ * It enables to notify applications a few events that will cause reset
+ * of userspace access vector without context switching.
+ *
+ * The selinux_kernel_status structure on the head of status page is
+ * protected from concurrent accesses using seqlock logic, so userspace
+ * application should reference the status page according to the seqlock
+ * logic.
+ *
+ * Typically, application checks status->sequence at the head of access
+ * control routine. If it is odd-number, kernel is updating the status,
+ * so please wait for a moment. If it is changed from the last sequence
+ * number, it means something happen, so application will reset userspace
+ * avc, if needed.
+ * In most cases, application shall confirm the kernel status is not
+ * changed without any system call invocations.
+ */
+static struct page *selinux_status_page = NULL;
+static DEFINE_MUTEX(selinux_status_lock);
+
+/*
+ * selinux_kernel_status_page
+ *
+ * It returns a reference to selinux_status_page. If the status page is
+ * not allocated yet, it also tries to allocate it at the first time.
+ */
+struct page *selinux_kernel_status_page(void)
+{
+ struct selinux_kernel_status *status;
+ struct page *result = NULL;
+
+ mutex_lock(&selinux_status_lock);
+ if (!selinux_status_page)
+ {
+ selinux_status_page = alloc_page(GFP_KERNEL|__GFP_ZERO);
+ if (selinux_status_page)
+ {
+ status = page_address(selinux_status_page);
+
+ status->version = SELINUX_KERNEL_STATUS_VERSION;
+ status->sequence = 0;
+ status->enforcing = selinux_enforcing;
+ /*
+ * NOTE: the next policyload event shall set
+ * a positive value on the status->policyload,
+ * although it may not be 1, but never zero.
+ * So, application can know it was updated.
+ */
+ status->policyload = 0;
+ status->deny_unknown = !security_get_allow_unknown();
+ }
+ }
+ result = selinux_status_page;
+ mutex_unlock(&selinux_status_lock);
+
+ return result;
+}
+
+/*
+ * selinux_status_update_setenforce
+ *
+ * It updates status of the current enforcing/permissive mode.
+ */
+void selinux_status_update_setenforce(int enforcing)
+{
+ struct selinux_kernel_status *status;
+
+ mutex_lock(&selinux_status_lock);
+ if (selinux_status_page)
+ {
+ status = page_address(selinux_status_page);
+
+ status->sequence++;
+ smp_wmb();
+
+ status->enforcing = enforcing;
+
+ smp_wmb();
+ status->sequence++;
+ }
+ mutex_unlock(&selinux_status_lock);
+}
+
+/*
+ * selinux_status_update_policyload
+ *
+ * It updates status of the times of policy reloaded, and current
+ * setting of deny_unknown.
+ */
+void selinux_status_update_policyload(int seqno)
+{
+ struct selinux_kernel_status *status;
+
+ mutex_lock(&selinux_status_lock);
+ if (selinux_status_page)
+ {
+ status = page_address(selinux_status_page);
+
+ status->sequence++;
+ smp_wmb();
+
+ status->policyload = seqno;
+ status->deny_unknown = !security_get_allow_unknown();
+
+ smp_wmb();
+ status->sequence++;
+ }
+ mutex_unlock(&selinux_status_lock);
+}