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author | KaiGai Kohei <kaigai@ak.jp.nec.com> | 2007-09-28 19:20:55 +0200 |
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committer | James Morris <jmorris@namei.org> | 2007-10-17 00:59:34 +0200 |
commit | 9fe79ad1e43d236bbbb8edb3cf634356de714c79 (patch) | |
tree | 91149cefa28baf692eb55f88f8c544a33e9126df /security/selinux/ss/services.c | |
parent | SELinux: policy selectable handling of unknown classes and perms (diff) | |
download | linux-9fe79ad1e43d236bbbb8edb3cf634356de714c79.tar.xz linux-9fe79ad1e43d236bbbb8edb3cf634356de714c79.zip |
SELinux: improve performance when AVC misses.
* We add ebitmap_for_each_positive_bit() which enables to walk on
any positive bit on the given ebitmap, to improve its performance
using common bit-operations defined in linux/bitops.h.
In the previous version, this logic was implemented using a combination
of ebitmap_for_each_bit() and ebitmap_node_get_bit(), but is was worse
in performance aspect.
This logic is most frequestly used to compute a new AVC entry,
so this patch can improve SELinux performance when AVC misses are happen.
* struct ebitmap_node is redefined as an array of "unsigned long", to get
suitable for using find_next_bit() which is fasted than iteration of
shift and logical operation, and to maximize memory usage allocated
from general purpose slab.
* Any ebitmap_for_each_bit() are repleced by the new implementation
in ss/service.c and ss/mls.c. Some of related implementation are
changed, however, there is no incompatibility with the previous
version.
* The width of any new line are less or equal than 80-chars.
The following benchmark shows the effect of this patch, when we
access many files which have different security context one after
another. The number is more than /selinux/avc/cache_threshold, so
any access always causes AVC misses.
selinux-2.6 selinux-2.6-ebitmap
AVG: 22.763 [s] 8.750 [s]
STD: 0.265 0.019
------------------------------------------
1st: 22.558 [s] 8.786 [s]
2nd: 22.458 [s] 8.750 [s]
3rd: 22.478 [s] 8.754 [s]
4th: 22.724 [s] 8.745 [s]
5th: 22.918 [s] 8.748 [s]
6th: 22.905 [s] 8.764 [s]
7th: 23.238 [s] 8.726 [s]
8th: 22.822 [s] 8.729 [s]
Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
Diffstat (limited to 'security/selinux/ss/services.c')
-rw-r--r-- | security/selinux/ss/services.c | 16 |
1 files changed, 4 insertions, 12 deletions
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 03140edf97a3..d572dc908f31 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -353,12 +353,8 @@ static int context_struct_compute_av(struct context *scontext, avkey.specified = AVTAB_AV; sattr = &policydb.type_attr_map[scontext->type - 1]; tattr = &policydb.type_attr_map[tcontext->type - 1]; - ebitmap_for_each_bit(sattr, snode, i) { - if (!ebitmap_node_get_bit(snode, i)) - continue; - ebitmap_for_each_bit(tattr, tnode, j) { - if (!ebitmap_node_get_bit(tnode, j)) - continue; + ebitmap_for_each_positive_bit(sattr, snode, i) { + ebitmap_for_each_positive_bit(tattr, tnode, j) { avkey.source_type = i + 1; avkey.target_type = j + 1; for (node = avtab_search_node(&policydb.te_avtab, &avkey); @@ -1668,14 +1664,10 @@ int security_get_user_sids(u32 fromsid, goto out_unlock; } - ebitmap_for_each_bit(&user->roles, rnode, i) { - if (!ebitmap_node_get_bit(rnode, i)) - continue; + ebitmap_for_each_positive_bit(&user->roles, rnode, i) { role = policydb.role_val_to_struct[i]; usercon.role = i+1; - ebitmap_for_each_bit(&role->types, tnode, j) { - if (!ebitmap_node_get_bit(tnode, j)) - continue; + ebitmap_for_each_positive_bit(&role->types, tnode, j) { usercon.type = j+1; if (mls_setup_user_range(fromcon, user, &usercon)) |