git: bda73e441f25 - main - posix shm: add shm_get_path(9)
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Date: Tue, 08 Oct 2024 12:39:24 UTC
The branch main has been updated by kib: URL: https://cgit.FreeBSD.org/src/commit/?id=bda73e441f2576de5ad00856d758354c299a3f75 commit bda73e441f2576de5ad00856d758354c299a3f75 Author: Konstantin Belousov <kib@FreeBSD.org> AuthorDate: 2024-10-07 01:44:49 +0000 Commit: Konstantin Belousov <kib@FreeBSD.org> CommitDate: 2024-10-08 12:38:03 +0000 posix shm: add shm_get_path(9) to calculate the posix shm path from the vm_object backing shm segment. Reviewed by: markj Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D46970 --- sys/kern/uipc_shm.c | 31 +++++++++++++++++++++++++++++++ sys/sys/mman.h | 1 + 2 files changed, 32 insertions(+) diff --git a/sys/kern/uipc_shm.c b/sys/kern/uipc_shm.c index cf98e1410074..f6861a3278ff 100644 --- a/sys/kern/uipc_shm.c +++ b/sys/kern/uipc_shm.c @@ -2208,3 +2208,34 @@ sys_shm_open2(struct thread *td, struct shm_open2_args *uap) return (kern_shm_open2(td, uap->path, uap->flags, uap->mode, uap->shmflags, NULL, uap->name)); } + +int +shm_get_path(struct vm_object *obj, char *path, size_t sz) +{ + struct shmfd *shmfd; + int error; + + error = 0; + shmfd = NULL; + sx_slock(&shm_dict_lock); + VM_OBJECT_RLOCK(obj); + if ((obj->flags & OBJ_POSIXSHM) == 0) { + error = EINVAL; + } else { + if (obj->type == shmfd_pager_type) + shmfd = obj->un_pager.swp.swp_priv; + else if (obj->type == OBJT_PHYS) + shmfd = obj->un_pager.phys.phys_priv; + if (shmfd == NULL) { + error = ENXIO; + } else { + strlcpy(path, shmfd->shm_path == NULL ? "anon" : + shmfd->shm_path, sz); + } + } + if (error != 0) + path[0] = '\0'; + VM_OBJECT_RUNLOCK(obj); + sx_sunlock(&shm_dict_lock); + return (error); +} diff --git a/sys/sys/mman.h b/sys/sys/mman.h index 6ee2d5562db1..d2c7bdf1f022 100644 --- a/sys/sys/mman.h +++ b/sys/sys/mman.h @@ -310,6 +310,7 @@ void shm_drop(struct shmfd *shmfd); int shm_dotruncate(struct shmfd *shmfd, off_t length); bool shm_largepage(struct shmfd *shmfd); void shm_remove_prison(struct prison *pr); +int shm_get_path(struct vm_object *obj, char *path, size_t sz); extern struct fileops shm_ops;