selinux: use GFP_NOWAIT in the AVC kmem_caches

There is a strange __GFP_NOMEMALLOC usage pattern in SELinux,
specifically GFP_ATOMIC | __GFP_NOMEMALLOC which doesn't make much
sense.  GFP_ATOMIC on its own allows to access memory reserves while
__GFP_NOMEMALLOC dictates we cannot use memory reserves.  Replace this
with the much more sane GFP_NOWAIT in the AVC code as we can tolerate
memory allocation failures in that code.

Signed-off-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Paul Moore <paul@paul-moore.com>
This commit is contained in:
Michal Hocko 2017-08-03 10:11:52 +02:00 committed by Paul Moore
parent af63f4193f
commit 476accbe2f

View File

@ -348,27 +348,26 @@ static struct avc_xperms_decision_node
struct avc_xperms_decision_node *xpd_node;
struct extended_perms_decision *xpd;
xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep,
GFP_ATOMIC | __GFP_NOMEMALLOC);
xpd_node = kmem_cache_zalloc(avc_xperms_decision_cachep, GFP_NOWAIT);
if (!xpd_node)
return NULL;
xpd = &xpd_node->xpd;
if (which & XPERMS_ALLOWED) {
xpd->allowed = kmem_cache_zalloc(avc_xperms_data_cachep,
GFP_ATOMIC | __GFP_NOMEMALLOC);
GFP_NOWAIT);
if (!xpd->allowed)
goto error;
}
if (which & XPERMS_AUDITALLOW) {
xpd->auditallow = kmem_cache_zalloc(avc_xperms_data_cachep,
GFP_ATOMIC | __GFP_NOMEMALLOC);
GFP_NOWAIT);
if (!xpd->auditallow)
goto error;
}
if (which & XPERMS_DONTAUDIT) {
xpd->dontaudit = kmem_cache_zalloc(avc_xperms_data_cachep,
GFP_ATOMIC | __GFP_NOMEMALLOC);
GFP_NOWAIT);
if (!xpd->dontaudit)
goto error;
}
@ -396,8 +395,7 @@ static struct avc_xperms_node *avc_xperms_alloc(void)
{
struct avc_xperms_node *xp_node;
xp_node = kmem_cache_zalloc(avc_xperms_cachep,
GFP_ATOMIC|__GFP_NOMEMALLOC);
xp_node = kmem_cache_zalloc(avc_xperms_cachep, GFP_NOWAIT);
if (!xp_node)
return xp_node;
INIT_LIST_HEAD(&xp_node->xpd_head);
@ -550,7 +548,7 @@ static struct avc_node *avc_alloc_node(void)
{
struct avc_node *node;
node = kmem_cache_zalloc(avc_node_cachep, GFP_ATOMIC|__GFP_NOMEMALLOC);
node = kmem_cache_zalloc(avc_node_cachep, GFP_NOWAIT);
if (!node)
goto out;