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2010-12-08selinux: cache sidtab_context_to_sid resultsEric Paris1-2/+37
sidtab_context_to_sid takes up a large share of time when creating large numbers of new inodes (~30-40% in oprofile runs). This patch implements a cache of 3 entries which is checked before we do a full context_to_sid lookup. On one system this showed over a x3 improvement in the number of inodes that could be created per second and around a 20% improvement on another system. Any time we look up the same context string sucessivly (imagine ls -lZ) we should hit this cache hot. A cache miss should have a relatively minor affect on performance next to doing the full table search. All operations on the cache are done COMPLETELY lockless. We know that all struct sidtab_node objects created will never be deleted until a new policy is loaded thus we never have to worry about a pointer being dereferenced. Since we also know that pointer assignment is atomic we know that the cache will always have valid pointers. Given this information we implement a FIFO cache in an array of 3 pointers. Every result (whether a cache hit or table lookup) will be places in the 0 spot of the cache and the rest of the entries moved down one spot. The 3rd entry will be lost. Races are possible and are even likely to happen. Lets assume that 4 tasks are hitting sidtab_context_to_sid. The first task checks against the first entry in the cache and it is a miss. Now lets assume a second task updates the cache with a new entry. This will push the first entry back to the second spot. Now the first task might check against the second entry (which it already checked) and will miss again. Now say some third task updates the cache and push the second entry to the third spot. The first task my check the third entry (for the third time!) and again have a miss. At which point it will just do a full table lookup. No big deal! Signed-off-by: Eric Paris <eparis@redhat.com>
2008-08-15selinux: Unify for- and while-loop styleVesa-Matti Kari1-6/+6
Replace "thing != NULL" comparisons with just "thing" to make the code look more uniform (mixed styles were used even in the same source file). Signed-off-by: Vesa-Matti Kari <vmkari@cc.helsinki.fi> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2008-07-14SELinux: open code sidtab lockJames Morris1-11/+7
Open code sidtab lock to make Andrew Morton happy. Signed-off-by: James Morris <jmorris@namei.org> Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
2008-07-14selinux: support deferred mapping of contextsStephen Smalley1-39/+19
Introduce SELinux support for deferred mapping of security contexts in the SID table upon policy reload, and use this support for inode security contexts when the context is not yet valid under the current policy. Only processes with CAP_MAC_ADMIN + mac_admin permission in policy can set undefined security contexts on inodes. Inodes with such undefined contexts are treated as having the unlabeled context until the context becomes valid upon a policy reload that defines the context. Context invalidation upon policy reload also uses this support to save the context information in the SID table and later recover it upon a subsequent policy reload that defines the context again. This support is to enable package managers and similar programs to set down file contexts unknown to the system policy at the time the file is created in order to better support placing loadable policy modules in packages and to support build systems that need to create images of different distro releases with different policies w/o requiring all of the contexts to be defined or legal in the build host policy. With this patch applied, the following sequence is possible, although in practice it is recommended that this permission only be allowed to specific program domains such as the package manager. # rmdir baz # rm bar # touch bar # chcon -t foo_exec_t bar # foo_exec_t is not yet defined chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument # mkdir -Z system_u:object_r:foo_exec_t baz mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument # cat setundefined.te policy_module(setundefined, 1.0) require { type unconfined_t; type unlabeled_t; } files_type(unlabeled_t) allow unconfined_t self:capability2 mac_admin; # make -f /usr/share/selinux/devel/Makefile setundefined.pp # semodule -i setundefined.pp # chcon -t foo_exec_t bar # foo_exec_t is not yet defined # mkdir -Z system_u:object_r:foo_exec_t baz # ls -Zd bar baz -rw-r--r-- root root system_u:object_r:unlabeled_t bar drwxr-xr-x root root system_u:object_r:unlabeled_t baz # cat foo.te policy_module(foo, 1.0) type foo_exec_t; files_type(foo_exec_t) # make -f /usr/share/selinux/devel/Makefile foo.pp # semodule -i foo.pp # defines foo_exec_t # ls -Zd bar baz -rw-r--r-- root root user_u:object_r:foo_exec_t bar drwxr-xr-x root root system_u:object_r:foo_exec_t baz # semodule -r foo # ls -Zd bar baz -rw-r--r-- root root system_u:object_r:unlabeled_t bar drwxr-xr-x root root system_u:object_r:unlabeled_t baz # semodule -i foo.pp # ls -Zd bar baz -rw-r--r-- root root user_u:object_r:foo_exec_t bar drwxr-xr-x root root system_u:object_r:foo_exec_t baz # semodule -r setundefined foo # chcon -t foo_exec_t bar # no longer defined and not allowed chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument # rmdir baz # mkdir -Z system_u:object_r:foo_exec_t baz mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2008-04-21SELinux: sidtab.c whitespace, syntax, and static declaraction cleanupsEric Paris1-4/+2
This patch changes sidtab.c to fix whitespace and syntax issues. Things that are fixed may include (does not not have to include) whitespace at end of lines spaces followed by tabs spaces used instead of tabs spacing around parenthesis locateion of { around struct and else clauses location of * in pointer declarations removal of initialization of static data to keep it in the right section useless {} in if statemetns useless checking for NULL before kfree fixing of the indentation depth of switch statements and any number of other things I forgot to mention Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2007-02-26Reassign printk levels in selinux kernel codeEric Paris1-1/+1
Below is a patch which demotes many printk lines to KERN_DEBUG from KERN_INFO. It should help stop the spamming of logs with messages in which users are not interested nor is there any action that users should take. It also promotes some KERN_INFO to KERN_ERR such as when there are improper attempts to register/unregister security modules. A similar patch was discussed a while back on list: http://marc.theaimsgroup.com/?t=116656343500003&r=1&w=2 This patch addresses almost all of the issues raised. I believe the only advice not taken was in the demoting of messages related to undefined permissions and classes. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> security/selinux/hooks.c | 20 ++++++++++---------- security/selinux/ss/avtab.c | 2 +- security/selinux/ss/policydb.c | 6 +++--- security/selinux/ss/sidtab.c | 2 +- 4 files changed, 15 insertions(+), 15 deletions(-) Signed-off-by: James Morris <jmorris@namei.org>
2007-02-14[PATCH] remove many unneeded #includes of sched.hTim Schmielau1-1/+0
After Al Viro (finally) succeeded in removing the sched.h #include in module.h recently, it makes sense again to remove other superfluous sched.h includes. There are quite a lot of files which include it but don't actually need anything defined in there. Presumably these includes were once needed for macros that used to live in sched.h, but moved to other header files in the course of cleaning it up. To ease the pain, this time I did not fiddle with any header files and only removed #includes from .c-files, which tend to cause less trouble. Compile tested against 2.6.20-rc2 and 2.6.20-rc2-mm2 (with offsets) on alpha, arm, i386, ia64, mips, powerpc, and x86_64 with allnoconfig, defconfig, allmodconfig, and allyesconfig as well as a few randconfigs on x86_64 and all configs in arch/arm/configs on arm. I also checked that no new warnings were introduced by the patch (actually, some warnings are removed that were emitted by unnecessarily included header files). Signed-off-by: Tim Schmielau <tim@physik3.uni-rostock.de> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2005-04-17Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds1-0/+305
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!