2 * Copyright (c) 2021-2022 Juniper Networks
4 * This software was developed by Mitchell Horne <mhorne@FreeBSD.org>
5 * under sponsorship from Juniper Networks and Klara Systems.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 #include <sys/param.h>
30 #include <sys/systm.h>
32 #include <sys/caprights.h>
34 #include <sys/eventhandler.h>
35 #include <sys/fcntl.h>
37 #include <sys/kerneldump.h>
38 #include <sys/limits.h>
39 #include <sys/malloc.h>
40 #include <sys/namei.h>
44 #include <sys/sysctl.h>
45 #include <sys/vnode.h>
47 #include <machine/vmparam.h>
49 static dumper_start_t vnode_dumper_start;
50 static dumper_t vnode_dump;
51 static dumper_hdr_t vnode_write_headers;
53 static struct sx livedump_sx;
54 SX_SYSINIT(livedump, &livedump_sx, "Livedump sx");
57 * Invoke a live minidump on the system.
60 livedump_start(int fd, int flags, uint8_t compression)
62 #if MINIDUMP_PAGE_TRACKING == 1
63 struct dumperinfo di, *livedi;
64 struct diocskerneldump_arg kda;
70 error = priv_check(curthread, PRIV_KMEM_READ);
77 error = getvnode(curthread, fd, &cap_write_rights, &fp);
82 if ((fp->f_flag & FWRITE) == 0) {
87 /* Set up a new dumper. */
88 bzero(&di, sizeof(di));
89 di.dumper_start = vnode_dumper_start;
90 di.dumper = vnode_dump;
91 di.dumper_hdr = vnode_write_headers;
92 di.blocksize = PAGE_SIZE; /* Arbitrary. */
93 di.maxiosize = MAXDUMPPGS * PAGE_SIZE;
95 bzero(&kda, sizeof(kda));
96 kda.kda_compression = compression;
97 error = dumper_create(&di, "livedump", &kda, &livedi);
101 /* Only allow one livedump to proceed at a time. */
102 if (sx_try_xlock(&livedump_sx) == 0) {
103 dumper_destroy(livedi);
108 /* To be used by the callback functions. */
111 /* Lock the entire file range and vnode. */
112 rl_cookie = vn_rangelock_wlock(vp, 0, OFF_MAX);
113 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
115 EVENTHANDLER_INVOKE(livedumper_start, &error);
120 error = minidumpsys(livedi, true);
122 EVENTHANDLER_INVOKE(livedumper_finish);
125 vn_rangelock_unlock(vp, rl_cookie);
126 sx_xunlock(&livedump_sx);
127 dumper_destroy(livedi);
129 fdrop(fp, curthread);
133 #endif /* MINIDUMP_PAGE_TRACKING == 1 */
137 vnode_dumper_start(struct dumperinfo *di, void *key, uint32_t keysize)
140 /* Always begin with an offset of zero. */
143 KASSERT(keysize == 0, ("encryption not supported for livedumps"));
148 * Callback from dumpsys() to dump a chunk of memory.
151 * arg Opaque private pointer to vnode
152 * virtual Virtual address (where to read the data from)
153 * offset Offset from start of core file
161 vnode_dump(void *arg, void *virtual, off_t offset, size_t length)
168 ASSERT_VOP_LOCKED(vp, __func__);
170 EVENTHANDLER_INVOKE(livedumper_dump, virtual, offset, length, &error);
178 error = vn_rdwr(UIO_WRITE, vp, virtual, length, offset, UIO_SYSSPACE,
179 IO_NODELOCKED, curthread->td_ucred, NOCRED, NULL, curthread);
181 uprintf("%s: error writing livedump block at offset %jx: %d\n",
182 __func__, (uintmax_t)offset, error);
187 * Callback from dumpsys() to write out the dump header, placed at the end.
190 vnode_write_headers(struct dumperinfo *di, struct kerneldumpheader *kdh)
198 ASSERT_VOP_LOCKED(vp, __func__);
200 /* Compensate for compression/encryption adjustment of dumpoff. */
201 offset = roundup2(di->dumpoff, di->blocksize);
203 /* Write the kernel dump header to the end of the file. */
204 error = vn_rdwr(UIO_WRITE, vp, kdh, sizeof(*kdh), offset,
205 UIO_SYSSPACE, IO_NODELOCKED, curthread->td_ucred, NOCRED, NULL,
208 uprintf("%s: error writing livedump header: %d\n", __func__,