git: 6a3fbdc7e9c8 - main - kinfo_vmobject: report backing object of the SysV shm segments

The branch main has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=6a3fbdc7e9c8323a1c13c4afcc65f89cb47911e6

commit 6a3fbdc7e9c8323a1c13c4afcc65f89cb47911e6
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2024-10-05 09:20:21 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2024-10-07 08:22:12 +0000

    kinfo_vmobject: report backing object of the SysV shm segments
    
    Use reserved work for kvo_flags.
    Mark such object with KVMO_FLAG_SYSVSHM.
    Provide segment key in kvo_vn_fileid, vnode never can back shm mapping.
    Provide sequence number in kvo_vn_fsid_freebsd11.
    
    Reviewed by:    markj
    Sponsored by:   The FreeBSD Foundation
    MFC after:      1 week
    Differential revision:  https://reviews.freebsd.org/D46959
---
 sys/sys/user.h     |  5 ++++-
 sys/vm/vm_object.c | 11 +++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/sys/sys/user.h b/sys/sys/user.h
index 00cfbf09b4d6..1fd802b03a42 100644
--- a/sys/sys/user.h
+++ b/sys/sys/user.h
@@ -577,6 +577,8 @@ struct kinfo_vmentry {
 #define	kve_vn_fsid	kve_type_spec._kve_vn_fsid
 #define	kve_obj		kve_type_spec._kve_obj
 
+#define	KVMO_FLAG_SYSVSHM	0x0001
+
 /*
  * The "vm.objects" sysctl provides a list of all VM objects in the system
  * via an array of these entries.
@@ -600,7 +602,8 @@ struct kinfo_vmobject {
 	uint64_t kvo_me;			/* Uniq handle for anon obj */
 	uint64_t _kvo_qspare[6];
 	uint32_t kvo_swapped;			/* Number of swapped pages */
-	uint32_t _kvo_ispare[7];
+	uint32_t kvo_flags;
+	uint32_t _kvo_ispare[6];
 	char	kvo_path[PATH_MAX];		/* Pathname, if any. */
 };
 #define	kvo_vn_fsid	kvo_type_spec._kvo_vn_fsid
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index 86f9271341df..85fc27d169d6 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -67,6 +67,7 @@
 #include <sys/systm.h>
 #include <sys/blockcount.h>
 #include <sys/cpuset.h>
+#include <sys/ipc.h>
 #include <sys/jail.h>
 #include <sys/limits.h>
 #include <sys/lock.h>
@@ -77,6 +78,7 @@
 #include <sys/pctrie.h>
 #include <sys/proc.h>
 #include <sys/refcount.h>
+#include <sys/shm.h>
 #include <sys/sx.h>
 #include <sys/sysctl.h>
 #include <sys/resourcevar.h>
@@ -2506,6 +2508,8 @@ vm_object_list_handler(struct sysctl_req *req, bool swap_only)
 	vm_page_t m;
 	u_long sp;
 	int count, error;
+	key_t key;
+	unsigned short seq;
 	bool want_path;
 
 	if (req->oldptr == NULL) {
@@ -2553,6 +2557,7 @@ vm_object_list_handler(struct sysctl_req *req, bool swap_only)
 		kvo->kvo_memattr = obj->memattr;
 		kvo->kvo_active = 0;
 		kvo->kvo_inactive = 0;
+		kvo->kvo_flags = 0;
 		if (!swap_only) {
 			TAILQ_FOREACH(m, &obj->memq, listq) {
 				/*
@@ -2590,6 +2595,12 @@ vm_object_list_handler(struct sysctl_req *req, bool swap_only)
 			kvo->kvo_swapped = sp > UINT32_MAX ? UINT32_MAX : sp;
 		}
 		VM_OBJECT_RUNLOCK(obj);
+		if ((obj->flags & OBJ_SYSVSHM) != 0) {
+			kvo->kvo_flags |= KVMO_FLAG_SYSVSHM;
+			shmobjinfo(obj, &key, &seq);
+			kvo->kvo_vn_fileid = key;
+			kvo->kvo_vn_fsid_freebsd11 = seq;
+		}
 		if (vp != NULL) {
 			vn_fullpath(vp, &fullpath, &freepath);
 			vn_lock(vp, LK_SHARED | LK_RETRY);