avc_open man page

avc_open, avc_destroy, avc_reset, avc_cleanup — userspace SELinux AVC setup and teardown


#include <selinux/selinux.h>
#include <selinux/avc.h>

int avc_open(struct selinux_opt *options, unsigned nopt);

void avc_destroy(void);

int avc_reset(void);

void avc_cleanup(void);


avc_open() initializes the userspace AVC and must be called before any other AVC operation can be performed.

avc_destroy() destroys the userspace AVC, freeing all internal memory structures. After this call has been made, avc_open() must be called again before any AVC operations can be performed.

avc_reset() flushes the userspace AVC, causing it to forget any cached access decisions. The userspace AVC normally calls this function automatically when needed, see Netlink Notification below.

avc_cleanup() attempts to free unused memory within the userspace AVC, but does not flush any cached access decisions. Under normal operation, calling this function should not be necessary.


The userspace AVC obeys callbacks set via selinux_set_callback(3), in particular the logging and audit callbacks.

The options which may be passed to avc_open() include the following:

This option forces the userspace AVC into enforcing mode if the option value is non-NULL; permissive mode otherwise. The system enforcing mode will be ignored.

Return Value

Functions with a return value return zero on success. On error, -1 is returned and errno is set appropriately.


Eamon Walsh <ewalsh@tycho.nsa.gov>

See Also

selinux(8), avc_has_perm(3), avc_context_to_sid(3), avc_cache_stats(3), avc_add_callback(3), selinux_set_callback(3), security_compute_av(3)

Referenced By

avc_add_callback(3), avc_context_to_sid(3), avc_init(3), avc_netlink_loop(3).

Explore man page connections for avc_open(3).

avc_cleanup(3), avc_destroy(3) and avc_reset(3) are aliases of avc_open(3).