The branch main has been updated by des: URL: https://cgit.FreeBSD.org/src/commit/?id=0620c99d278b6a2fd6fe995f5bb365158e04ad7c
commit 0620c99d278b6a2fd6fe995f5bb365158e04ad7c Author: Dag-Erling Smørgrav <[email protected]> AuthorDate: 2026-06-05 21:50:38 +0000 Commit: Dag-Erling Smørgrav <[email protected]> CommitDate: 2026-06-05 21:50:38 +0000 audit: Add poll / select support It was previously not possible to poll() or select() on the trigger device, which made implementing proper signal handling in auditd difficult. MFC after: 1 week Sponsored by: Klara, Inc. Reviewed by: kevans, markj Differential Revision: https://reviews.freebsd.org/D57457 --- sys/security/audit/audit_trigger.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/sys/security/audit/audit_trigger.c b/sys/security/audit/audit_trigger.c index 482f7c56a2ef..e2520292cc5d 100644 --- a/sys/security/audit/audit_trigger.c +++ b/sys/security/audit/audit_trigger.c @@ -32,8 +32,10 @@ #include <sys/lock.h> #include <sys/malloc.h> #include <sys/mutex.h> +#include <sys/poll.h> #include <sys/proc.h> #include <sys/queue.h> +#include <sys/selinfo.h> #include <sys/systm.h> #include <sys/uio.h> @@ -45,8 +47,6 @@ * used to communicate with userland. /dev/audit reliably delivers one-byte * messages to a listening application (or discards them if there is no * listening application). - * - * Currently, select/poll are not supported on the trigger device. */ struct trigger_info { unsigned int trigger; @@ -58,6 +58,7 @@ static struct cdev *audit_dev; static int audit_isopen = 0; static TAILQ_HEAD(, trigger_info) trigger_list; static struct mtx audit_trigger_mtx; +static struct selinfo audit_trigger_rsel; static int audit_open(struct cdev *dev, int oflags, int devtype, struct thread *td) @@ -127,6 +128,22 @@ audit_write(struct cdev *dev, struct uio *uio, int ioflag) return (EOPNOTSUPP); } +static int +audit_poll(struct cdev *dev, int events, struct thread *td) +{ + int revents = 0; + + if (events & (POLLIN | POLLRDNORM)) { + mtx_lock(&audit_trigger_mtx); + if (!TAILQ_EMPTY(&trigger_list)) + revents = events & (POLLIN | POLLRDNORM); + else + selrecord(td, &audit_trigger_rsel); + mtx_unlock(&audit_trigger_mtx); + } + return (revents); +} + int audit_send_trigger(unsigned int trigger) { @@ -142,6 +159,7 @@ audit_send_trigger(unsigned int trigger) } ti->trigger = trigger; TAILQ_INSERT_TAIL(&trigger_list, ti, list); + selwakeup(&audit_trigger_rsel); wakeup(&trigger_list); mtx_unlock(&audit_trigger_mtx); return (0); @@ -153,6 +171,7 @@ static struct cdevsw audit_cdevsw = { .d_close = audit_close, .d_read = audit_read, .d_write = audit_write, + .d_poll = audit_poll, .d_name = "audit" };
