p_candebug

NAME

p_candebug — determine debuggability of a process

#include <sys/param.h>
#include <sys/proc.h>

int
p_candebug(struct thread *td, struct proc *p);

This function can be used to determine if a given process p is debuggable by the thread td.

The following sysctl(8) variables directly influence the behaviour of p_candebug():

kern.securelevel: Debugging of the init process is not allowed if this variable is 1 or greater.
security.bsd.unprivileged_proc_debug: Must be set to a non-zero value to allow unprivileged processes access to the kernel's debug facilities.

The p_candebug() function returns 0 if the process denoted by p is debuggable by thread td, or a non-zero error return value otherwise.

[EACCESS]: The MAC subsystem denied debuggability.
[EAGAIN]: Process p is in the process of being exec()'ed.
[EPERM]: Thread td lacks super-user credentials and process p is executing a set-user-ID or set-group-ID executable.
[EPERM]: Thread td lacks super-user credentials and process p's group set is not a subset of td's effective group set.
[EPERM]: Thread td lacks super-user credentials and process p's user IDs do not match thread td's effective user ID.
[EPERM]: Process p denotes the initial process initproc() and the sysctl(8) variable kern.securelevel is greater than zero.
[ESRCH]: Process p is not visible to thread td as determined by cr_seeotheruids(9) or cr_seeothergids(9).
[ESRCH]: Thread td has been jailed and process p does not belong to the same jail as td.
[ESRCH]: The MAC subsystem denied debuggability.