LSM: shrink sizeof LSM specific portion of common_audit_data
Linus found that the gigantic size of the common audit data caused a big
perf hit on something as simple as running stat() in a loop. This patch
requires LSMs to declare the LSM specific portion separately rather than
doing it in a union. Thus each LSM can be responsible for shrinking their
portion and don't have to pay a penalty just because other LSMs have a
bigger space requirement.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 1a70fa2..00f3860 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -436,9 +436,9 @@
{
struct common_audit_data *ad = a;
audit_log_format(ab, "avc: %s ",
- ad->selinux_audit_data.denied ? "denied" : "granted");
- avc_dump_av(ab, ad->selinux_audit_data.tclass,
- ad->selinux_audit_data.audited);
+ ad->selinux_audit_data->denied ? "denied" : "granted");
+ avc_dump_av(ab, ad->selinux_audit_data->tclass,
+ ad->selinux_audit_data->audited);
audit_log_format(ab, " for ");
}
@@ -452,9 +452,9 @@
{
struct common_audit_data *ad = a;
audit_log_format(ab, " ");
- avc_dump_query(ab, ad->selinux_audit_data.ssid,
- ad->selinux_audit_data.tsid,
- ad->selinux_audit_data.tclass);
+ avc_dump_query(ab, ad->selinux_audit_data->ssid,
+ ad->selinux_audit_data->tsid,
+ ad->selinux_audit_data->tclass);
}
/* This is the slow part of avc audit with big stack footprint */
@@ -464,10 +464,12 @@
unsigned flags)
{
struct common_audit_data stack_data;
+ struct selinux_audit_data sad = {0,};
if (!a) {
a = &stack_data;
COMMON_AUDIT_DATA_INIT(a, NONE);
+ a->selinux_audit_data = &sad;
}
/*
@@ -481,12 +483,12 @@
(flags & MAY_NOT_BLOCK))
return -ECHILD;
- a->selinux_audit_data.tclass = tclass;
- a->selinux_audit_data.requested = requested;
- a->selinux_audit_data.ssid = ssid;
- a->selinux_audit_data.tsid = tsid;
- a->selinux_audit_data.audited = audited;
- a->selinux_audit_data.denied = denied;
+ a->selinux_audit_data->tclass = tclass;
+ a->selinux_audit_data->requested = requested;
+ a->selinux_audit_data->ssid = ssid;
+ a->selinux_audit_data->tsid = tsid;
+ a->selinux_audit_data->audited = audited;
+ a->selinux_audit_data->denied = denied;
a->lsm_pre_audit = avc_audit_pre_callback;
a->lsm_post_audit = avc_audit_post_callback;
common_lsm_audit(a);
@@ -523,7 +525,7 @@
if (unlikely(denied)) {
audited = denied & avd->auditdeny;
/*
- * a->selinux_audit_data.auditdeny is TRICKY! Setting a bit in
+ * a->selinux_audit_data->auditdeny is TRICKY! Setting a bit in
* this field means that ANY denials should NOT be audited if
* the policy contains an explicit dontaudit rule for that
* permission. Take notice that this is unrelated to the
@@ -532,15 +534,15 @@
*
* denied == READ
* avd.auditdeny & ACCESS == 0 (not set means explicit rule)
- * selinux_audit_data.auditdeny & ACCESS == 1
+ * selinux_audit_data->auditdeny & ACCESS == 1
*
* We will NOT audit the denial even though the denied
* permission was READ and the auditdeny checks were for
* ACCESS
*/
if (a &&
- a->selinux_audit_data.auditdeny &&
- !(a->selinux_audit_data.auditdeny & avd->auditdeny))
+ a->selinux_audit_data->auditdeny &&
+ !(a->selinux_audit_data->auditdeny & avd->auditdeny))
audited = 0;
} else if (result)
audited = denied = requested;