src/sys/bsm, branch main

sys: add AUE_PDOPENPID

2026-07-07T01:25:08Z

Reviewed by: markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D57124

sys: add AUE_PDRFORK

2026-01-25T15:53:02Z

Reviewed by: asomers, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D54592

vfs: Initial revision of inotify

2025-07-04T14:42:33Z

Add an implementation of inotify_init(), inotify_add_watch(), inotify_rm_watch(), source-compatible with Linux. This provides functionality similar to kevent(2)'s EVFILT_VNODE, i.e., it lets applications monitor filesystem files for accesses. Compared to inotify, however, EVFILT_VNODE has the limitation of requiring the application to open the file to be monitored. This means that activity on a newly created file cannot be monitored reliably, and that a file descriptor per file in the hierarchy is required. inotify on the other hand allows a directory and its entries to be monitored at once. It introduces a new file descriptor type to which "watches" can be attached; a watch is a pseudo-file descriptor associated with a file or directory and a set of events to watch for. When a watched vnode is accessed, a description of the event is queued to the inotify descriptor, readable with read(2). Events for files in a watched directory include the file name. A watched vnode has its usecount bumped, so name cache entries originating from a watched directory are not evicted. Name cache entries are used to populate inotify events for files with a link in a watched directory. In particular, if a file is accessed with, say, read(2), an IN_ACCESS event will be generated for any watched hard link of the file. The inotify_add_watch_at() variant is included so that this functionality is available in capability mode; plain inotify_add_watch() is disallowed in capability mode. When a file in a nullfs mount is watched, the watch is attached to the lower vnode, such that accesses via either layer generate inotify events. Many thanks to Gleb Popov for testing this patch and finding lots of bugs. PR: 258010, 215011 Reviewed by: kib Tested by: arrowd MFC after: 3 months Sponsored by: Klara, Inc. Differential Revision: https://reviews.freebsd.org/D50315

New setcred() system call and associated MAC hooks

2024-12-16T14:42:39Z

This new system call allows to set all necessary credentials of a process in one go: Effective, real and saved UIDs, effective, real and saved GIDs, supplementary groups and the MAC label. Its advantage over standard credential-setting system calls (such as setuid(), seteuid(), etc.) is that it enables MAC modules, such as MAC/do, to restrict the set of credentials some process may gain in a fine-grained manner. Traditionally, credential changes rely on setuid binaries that call multiple credential system calls and in a specific order (setuid() must be last, so as to remain root for all other credential-setting calls, which would otherwise fail with insufficient privileges). This piecewise approach causes the process to transiently hold credentials that are neither the original nor the final ones. For the kernel to enforce that only certain transitions of credentials are allowed, either these possibly non-compliant transient states have to disappear (by setting all relevant attributes in one go), or the kernel must delay setting or checking the new credentials. Delaying setting credentials could be done, e.g., by having some mode where the standard system calls contribute to building new credentials but without committing them. It could be started and ended by a special system call. Delaying checking could mean that, e.g., the kernel only verifies the credentials transition at the next non-credential-setting system call (we just mention this possibility for completeness, but are certainly not endorsing it). We chose the simpler approach of a new system call, as we don't expect the set of credentials one can set to change often. It has the advantages that the traditional system calls' code doesn't have to be changed and that we can establish a special MAC protocol for it, by having some cleanup function called just before returning (this is a requirement for MAC/do), without disturbing the existing ones. The mac_cred_check_setcred() hook is passed the flags received by setcred() (including the version) and both the old and new kernel's 'struct ucred' instead of 'struct setcred' as this should simplify evolving existing hooks as the 'struct setcred' structure evolves. The mac_cred_setcred_enter() and mac_cred_setcred_exit() hooks are always called by pairs around potential calls to mac_cred_check_setcred(). They allow MAC modules to allocate/free data they may need in their mac_cred_check_setcred() hook, as the latter is called under the current process' lock, rendering sleepable allocations impossible. MAC/do is going to leverage these in a subsequent commit. A scheme where mac_cred_check_setcred() could return ERESTART was considered but is incompatible with proper composition of MAC modules. While here, add missing includes and declarations for standalone inclusion of both from kernel and userspace (for the latter, it has been working thanks to already including ). Reviewed by: brooks Approved by: markj (mentor) Relnotes: yes Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D47618

timerfd: Move implementation from linux compat to sys/kern

2023-08-24T20:28:56Z

Move the timerfd impelemntation from linux compat code to sys/kern. Use it to implement the new system calls for timerfd. Add a hook to kern_tc to allow timerfd to know when the system time has stepped. Add kqueue support to timerfd. Adjust a few names to be less Linux centric. RelNotes: YES Reviewed by: markj (on irc), imp, kib (with reservations), jhb (slack) Differential Revision: https://reviews.freebsd.org/D38459

sys: Remove $FreeBSD$: two-line .h pattern

2023-08-16T17:54:11Z

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

Add fspacectl(2), vn_deallocate(9) and VOP_DEALLOCATE(9).

2021-08-05T15:20:42Z

fspacectl(2) is a system call to provide space management support to userspace applications. VOP_DEALLOCATE(9) is a VOP call to perform the deallocation. vn_deallocate(9) is a public KPI for kmods' use. The purpose of proposing a new system call, a KPI and a VOP call is to allow bhyve or other hypervisor monitors to emulate the behavior of SCSI UNMAP/NVMe DEALLOCATE on a plain file. fspacectl(2) comprises of cmd and flags parameters to specify the space management operation to be performed. Currently cmd has to be SPACECTL_DEALLOC, and flags has to be 0. fo_fspacectl is added to fileops. VOP_DEALLOCATE(9) is added as a new VOP call. A trivial implementation of VOP_DEALLOCATE(9) is provided. Sponsored by: The FreeBSD Foundation Reviewed by: kib Differential Revision: https://reviews.freebsd.org/D28347

Add aio_writev and aio_readv

2021-01-03T02:57:58Z

POSIX AIO is great, but it lacks vectored I/O functions. This commit fixes that shortcoming by adding aio_writev and aio_readv. They aren't part of the standard, but they're an obvious extension. They work just like their synchronous equivalents pwritev and preadv. It isn't yet possible to use vectored aiocbs with lio_listio, but that could be added in the future. Reviewed by: jhb, kib, bcr Relnotes: yes Differential Revision: https://reviews.freebsd.org/D27743

Expose eventfd in the native API/ABI using a new __specialfd syscall

2020-12-27T10:57:26Z

eventfd is a Linux system call that produces special file descriptors for event notification. When porting Linux software, it is currently usually emulated by epoll-shim on top of kqueues. Unfortunately, kqueues are not passable between processes. And, as noted by the author of epoll-shim, even if they were, the library state would also have to be passed somehow. This came up when debugging strange HW video decode failures in Firefox. A native implementation would avoid these problems and help with porting Linux software. Since we now already have an eventfd implementation in the kernel (for the Linuxulator), it's pretty easy to expose it natively, which is what this patch does. Submitted by: greg@unrelenting.technology Reviewed by: markj (previous version) MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D26668

bsm: add AUE_CLOSERANGE

2020-04-24T01:27:25Z

AUE_CLOSERANGE has been accepted upstream as 43265; AUE_REALPATHAT has now been upstreamed.