diff options
author | Eric Paris <eparis@redhat.com> | 2010-07-30 03:02:34 (GMT) |
---|---|---|
committer | James Morris <jmorris@namei.org> | 2010-08-02 05:38:39 (GMT) |
commit | 6371dcd36f649d9d07823f31400618155a20dde1 (patch) | |
tree | a08c4ed2ec77225abbfcc099e78ae8d643429787 /security/selinux/ss/policydb.c | |
parent | 016d825fe02cd20fd8803ca37a1e6d428fe878f6 (diff) | |
download | linux-6371dcd36f649d9d07823f31400618155a20dde1.tar.xz |
selinux: convert the policy type_attr_map to flex_array
Current selinux policy can have over 3000 types. The type_attr_map in
policy is an array sized by the number of types times sizeof(struct ebitmap)
(12 on x86_64). Basic math tells us the array is going to be of length
3000 x 12 = 36,000 bytes. The largest 'safe' allocation on a long running
system is 16k. Most of the time a 32k allocation will work. But on long
running systems a 64k allocation (what we need) can fail quite regularly.
In order to deal with this I am converting the type_attr_map to use
flex_arrays. Let the library code deal with breaking this into PAGE_SIZE
pieces.
-v2
rework some of the if(!obj) BUG() to be BUG_ON(!obj)
drop flex_array_put() calls and just use a _get() object directly
-v3
make apply to James' tree (drop the policydb_write changes)
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security/selinux/ss/policydb.c')
-rw-r--r-- | security/selinux/ss/policydb.c | 41 |
1 files changed, 31 insertions, 10 deletions
diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 674ddfe..3a29704 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -31,6 +31,7 @@ #include <linux/string.h> #include <linux/errno.h> #include <linux/audit.h> +#include <linux/flex_array.h> #include "security.h" #include "policydb.h" @@ -739,11 +740,17 @@ void policydb_destroy(struct policydb *p) hashtab_map(p->range_tr, range_tr_destroy, NULL); hashtab_destroy(p->range_tr); - if (p->type_attr_map) { - for (i = 0; i < p->p_types.nprim; i++) - ebitmap_destroy(&p->type_attr_map[i]); + if (p->type_attr_map_array) { + for (i = 0; i < p->p_types.nprim; i++) { + struct ebitmap *e; + + e = flex_array_get(p->type_attr_map_array, i); + if (!e) + continue; + ebitmap_destroy(e); + } + flex_array_free(p->type_attr_map_array); } - kfree(p->type_attr_map); ebitmap_destroy(&p->policycaps); ebitmap_destroy(&p->permissive_map); @@ -2257,19 +2264,33 @@ int policydb_read(struct policydb *p, void *fp) if (rc) goto bad; - p->type_attr_map = kmalloc(p->p_types.nprim * sizeof(struct ebitmap), GFP_KERNEL); - if (!p->type_attr_map) + rc = -ENOMEM; + p->type_attr_map_array = flex_array_alloc(sizeof(struct ebitmap), + p->p_types.nprim, + GFP_KERNEL | __GFP_ZERO); + if (!p->type_attr_map_array) + goto bad; + + /* preallocate so we don't have to worry about the put ever failing */ + rc = flex_array_prealloc(p->type_attr_map_array, 0, p->p_types.nprim - 1, + GFP_KERNEL | __GFP_ZERO); + if (rc) goto bad; for (i = 0; i < p->p_types.nprim; i++) { - ebitmap_init(&p->type_attr_map[i]); + struct ebitmap *e = flex_array_get(p->type_attr_map_array, i); + + BUG_ON(!e); + ebitmap_init(e); if (p->policyvers >= POLICYDB_VERSION_AVTAB) { - if (ebitmap_read(&p->type_attr_map[i], fp)) + rc = ebitmap_read(e, fp); + if (rc) goto bad; } /* add the type itself as the degenerate case */ - if (ebitmap_set_bit(&p->type_attr_map[i], i, 1)) - goto bad; + rc = ebitmap_set_bit(e, i, 1); + if (rc) + goto bad; } rc = policydb_bounds_sanity_check(p); |