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path: root/security/selinux/ss/ebitmap.h
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2014-08-01netlabel: shorter names for the NetLabel catmap funcs/structsPaul Moore
Historically the NetLabel LSM secattr catmap functions and data structures have had very long names which makes a mess of the NetLabel code and anyone who uses NetLabel. This patch renames the catmap functions and structures from "*_secattr_catmap_*" to just "*_catmap_*" which improves things greatly. There are no substantial code or logic changes in this patch. Signed-off-by: Paul Moore <pmoore@redhat.com> Tested-by: Casey Schaufler <casey@schaufler-ca.com>
2013-07-25SELinux: Increase ebitmap_node size for 64-bit configurationWaiman Long
Currently, the ebitmap_node structure has a fixed size of 32 bytes. On a 32-bit system, the overhead is 8 bytes, leaving 24 bytes for being used as bitmaps. The overhead ratio is 1/4. On a 64-bit system, the overhead is 16 bytes. Therefore, only 16 bytes are left for bitmap purpose and the overhead ratio is 1/2. With a 3.8.2 kernel, a boot-up operation will cause the ebitmap_get_bit() function to be called about 9 million times. The average number of ebitmap_node traversal is about 3.7. This patch increases the size of the ebitmap_node structure to 64 bytes for 64-bit system to keep the overhead ratio at 1/4. This may also improve performance a little bit by making node to node traversal less frequent (< 2) as more bits are available in each node. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2013-07-25SELinux: Reduce overhead of mls_level_isvalid() function callWaiman Long
While running the high_systime workload of the AIM7 benchmark on a 2-socket 12-core Westmere x86-64 machine running 3.10-rc4 kernel (with HT on), it was found that a pretty sizable amount of time was spent in the SELinux code. Below was the perf trace of the "perf record -a -s" of a test run at 1500 users: 5.04% ls [kernel.kallsyms] [k] ebitmap_get_bit 1.96% ls [kernel.kallsyms] [k] mls_level_isvalid 1.95% ls [kernel.kallsyms] [k] find_next_bit The ebitmap_get_bit() was the hottest function in the perf-report output. Both the ebitmap_get_bit() and find_next_bit() functions were, in fact, called by mls_level_isvalid(). As a result, the mls_level_isvalid() call consumed 8.95% of the total CPU time of all the 24 virtual CPUs which is quite a lot. The majority of the mls_level_isvalid() function invocations come from the socket creation system call. Looking at the mls_level_isvalid() function, it is checking to see if all the bits set in one of the ebitmap structure are also set in another one as well as the highest set bit is no bigger than the one specified by the given policydb data structure. It is doing it in a bit-by-bit manner. So if the ebitmap structure has many bits set, the iteration loop will be done many times. The current code can be rewritten to use a similar algorithm as the ebitmap_contains() function with an additional check for the highest set bit. The ebitmap_contains() function was extended to cover an optional additional check for the highest set bit, and the mls_level_isvalid() function was modified to call ebitmap_contains(). With that change, the perf trace showed that the used CPU time drop down to just 0.08% (ebitmap_contains + mls_level_isvalid) of the total which is about 100X less than before. 0.07% ls [kernel.kallsyms] [k] ebitmap_contains 0.05% ls [kernel.kallsyms] [k] ebitmap_get_bit 0.01% ls [kernel.kallsyms] [k] mls_level_isvalid 0.01% ls [kernel.kallsyms] [k] find_next_bit The remaining ebitmap_get_bit() and find_next_bit() functions calls are made by other kernel routines as the new mls_level_isvalid() function will not call them anymore. This patch also improves the high_systime AIM7 benchmark result, though the improvement is not as impressive as is suggested by the reduction in CPU time spent in the ebitmap functions. The table below shows the performance change on the 2-socket x86-64 system (with HT on) mentioned above. +--------------+---------------+----------------+-----------------+ | Workload | mean % change | mean % change | mean % change | | | 10-100 users | 200-1000 users | 1100-2000 users | +--------------+---------------+----------------+-----------------+ | high_systime | +0.1% | +0.9% | +2.6% | +--------------+---------------+----------------+-----------------+ Signed-off-by: Waiman Long <Waiman.Long@hp.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2011-01-24security:selinux: kill unused MAX_AVTAB_HASH_MASK and ebitmap_startbitShan Wei
Kill unused MAX_AVTAB_HASH_MASK and ebitmap_startbit. Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21SELinux: allow userspace to read policy back out of the kernelEric Paris
There is interest in being able to see what the actual policy is that was loaded into the kernel. The patch creates a new selinuxfs file /selinux/policy which can be read by userspace. The actual policy that is loaded into the kernel will be written back out to userspace. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2007-10-17SELinux: kills warnings in Improve SELinux performance when AVC missesKaiGai Kohei
This patch kills ugly warnings when the "Improve SELinux performance when ACV misses" patch. Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> Signed-off-by: James Morris <jmorris@namei.org>
2007-10-17SELinux: improve performance when AVC misses.KaiGai Kohei
* 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>
2006-12-02NetLabel: convert to an extensibile/sparse category bitmapPaul Moore
The original NetLabel category bitmap was a straight char bitmap which worked fine for the initial release as it only supported 240 bits due to limitations in the CIPSO restricted bitmap tag (tag type 0x01). This patch converts that straight char bitmap into an extensibile/sparse bitmap in order to lay the foundation for other CIPSO tag types and protocols. This patch also has a nice side effect in that all of the security attributes passed by NetLabel into the LSM are now in a format which is in the host's native byte/bit ordering which makes the LSM specific code much simpler; look at the changes in security/selinux/ss/ebitmap.c as an example. Signed-off-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
2006-09-22[NetLabel]: SELinux supportVenkat Yekkirala
Add NetLabel support to the SELinux LSM and modify the socket_post_create() LSM hook to return an error code. The most significant part of this patch is the addition of NetLabel hooks into the following SELinux LSM hooks: * selinux_file_permission() * selinux_socket_sendmsg() * selinux_socket_post_create() * selinux_socket_sock_rcv_skb() * selinux_socket_getpeersec_stream() * selinux_socket_getpeersec_dgram() * selinux_sock_graft() * selinux_inet_conn_request() The basic reasoning behind this patch is that outgoing packets are "NetLabel'd" by labeling their socket and the NetLabel security attributes are checked via the additional hook in selinux_socket_sock_rcv_skb(). NetLabel itself is only a labeling mechanism, similar to filesystem extended attributes, it is up to the SELinux enforcement mechanism to perform the actual access checks. In addition to the changes outlined above this patch also includes some changes to the extended bitmap (ebitmap) and multi-level security (mls) code to import and export SELinux TE/MLS attributes into and out of NetLabel. Signed-off-by: Paul Moore <paul.moore@hp.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2005-09-05[PATCH] selinux: Reduce memory use by avtabStephen Smalley
This patch improves memory use by SELinux by both reducing the avtab node size and reducing the number of avtab nodes. The memory savings are substantial, e.g. on a 64-bit system after boot, James Morris reported the following data for the targeted and strict policies: #objs objsize kernmem Targeted: Before: 237888 40 9.1MB After: 19968 24 468KB Strict: Before: 571680 40 21.81MB After: 221052 24 5.06MB The improvement in memory use comes at a cost in the speed of security server computations of access vectors, but these computations are only required on AVC cache misses, and performance measurements by James Morris using a number of benchmarks have shown that the change does not cause any significant degradation. Note that a rebuilt policy via an updated policy toolchain (libsepol/checkpolicy) is required in order to gain the full benefits of this patch, although some memory savings benefits are immediately applied even to older policies (in particular, the reduction in avtab node size). Sources for the updated toolchain are presently available from the sourceforge CVS tree (http://sourceforge.net/cvs/?group_id=21266), and tarballs are available from http://www.flux.utah.edu/~sds. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!