man pages section 9: DDI and DKI Kernel Functions

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Updated: July 2014



drv_priv - determine driver privilege


#include <sys/types.h>
#include <sys/cred.h>
#include <sys/ddi.h>

int drv_priv(cred_t *cr);

Interface Level

Architecture independent level 1 (DDI/DKI).



Pointer to the user credential structure.


The drv_priv() function provides a general interface to the system privilege policy. It determines whether the credentials supplied by the user credential structure pointed to by cr identify a process that has the {PRIV_SYS_DEVICES} privilege asserted in its effective set. This function should be used only when file access modes, special minor device numbers, and the device policy (see privileges(5), add_drv(1M)) are insufficient to provide protection for the requested driver function. It is intended to replace all calls to suser() and any explicit checks for effective user ID = 0 in driver code.

Return Values

This routine returns 0 if it succeeds, EPERM if it fails.


The drv_priv() function can be called from user, interrupt, or kernel context.

See also

add_drv(1M), update_drv(1M), privileges(5)

Writing Device Drivers for Oracle Solaris 11.2