1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2016-2018, Matthew Macy <mmacy@freebsd.org> 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 * 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include <sys/param.h> 33 #include <sys/systm.h> 34 #include <sys/queue.h> 35 #include <sys/blist.h> 36 #include <sys/conf.h> 37 #include <sys/exec.h> 38 #include <sys/filedesc.h> 39 #include <sys/kernel.h> 40 #include <sys/linker.h> 41 #include <sys/malloc.h> 42 #include <sys/mount.h> 43 #include <sys/mutex.h> 44 #include <sys/proc.h> 45 #include <sys/resourcevar.h> 46 #include <sys/sbuf.h> 47 #include <sys/smp.h> 48 #include <sys/socket.h> 49 #include <sys/vnode.h> 50 #include <sys/bus.h> 51 #include <sys/pciio.h> 52 53 #include <dev/pci/pcivar.h> 54 #include <dev/pci/pcireg.h> 55 56 #include <net/if.h> 57 58 #include <vm/vm.h> 59 #include <vm/pmap.h> 60 #include <vm/vm_map.h> 61 #include <vm/vm_param.h> 62 #include <vm/vm_object.h> 63 #include <vm/swap_pager.h> 64 65 #include <machine/bus.h> 66 67 #include <compat/linux/linux_ioctl.h> 68 #include <compat/linux/linux_mib.h> 69 #include <compat/linux/linux_util.h> 70 #include <fs/pseudofs/pseudofs.h> 71 72 #include <linux/debugfs.h> 73 #include <linux/seq_file.h> 74 #include <linux/compat.h> 75 76 MALLOC_DEFINE(M_DFSINT, "debugfsint", "Linux debugfs internal"); 77 78 static struct pfs_node *debugfs_root; 79 80 #define DM_SYMLINK 0x1 81 #define DM_DIR 0x2 82 #define DM_FILE 0x3 83 84 struct dentry_meta { 85 struct dentry dm_dnode; 86 const struct file_operations *dm_fops; 87 void *dm_data; 88 umode_t dm_mode; 89 int dm_type; 90 }; 91 92 static int 93 debugfs_attr(PFS_ATTR_ARGS) 94 { 95 struct dentry_meta *dm; 96 97 dm = pn->pn_data; 98 99 vap->va_mode = dm->dm_mode; 100 return (0); 101 } 102 103 static int 104 debugfs_destroy(PFS_DESTROY_ARGS) 105 { 106 struct dentry_meta *dm; 107 108 dm = pn->pn_data; 109 if (dm->dm_type == DM_SYMLINK) 110 free(dm->dm_data, M_DFSINT); 111 112 free(dm, M_DFSINT); 113 return (0); 114 } 115 116 static int 117 debugfs_fill(PFS_FILL_ARGS) 118 { 119 struct dentry_meta *d; 120 struct linux_file lf = {}; 121 struct seq_file *sf; 122 struct vnode vn; 123 void *buf; 124 int rc; 125 size_t len; 126 off_t off; 127 128 d = pn->pn_data; 129 130 if ((rc = linux_set_current_flags(curthread, M_NOWAIT))) 131 return (rc); 132 vn.v_data = d->dm_data; 133 if (uio->uio_rw == UIO_READ) { 134 buf = uio->uio_iov[0].iov_base; 135 len = min(uio->uio_iov[0].iov_len, uio->uio_resid); 136 } else { 137 sbuf_finish(sb); 138 buf = sbuf_data(sb); 139 len = sbuf_len(sb); 140 } 141 off = 0; 142 rc = d->dm_fops->open(&vn, &lf); 143 if (rc < 0) { 144 #ifdef INVARIANTS 145 printf("%s:%d open failed with %d\n", __FUNCTION__, __LINE__, rc); 146 #endif 147 return (-rc); 148 } 149 sf = lf.private_data; 150 sf->buf = sb; 151 if (uio->uio_rw == UIO_READ) { 152 if (d->dm_fops->read) 153 rc = d->dm_fops->read(&lf, NULL, len, &off); 154 else 155 rc = -ENODEV; 156 } else { 157 if (d->dm_fops->write) 158 rc = d->dm_fops->write(&lf, buf, len, &off); 159 else 160 rc = -ENODEV; 161 } 162 if (d->dm_fops->release) 163 d->dm_fops->release(&vn, &lf); 164 else 165 single_release(&vn, &lf); 166 167 if (rc < 0) { 168 #ifdef INVARIANTS 169 printf("%s:%d read/write failed with %d\n", __FUNCTION__, __LINE__, rc); 170 #endif 171 return (-rc); 172 } 173 return (0); 174 } 175 176 static int 177 debugfs_fill_data(PFS_FILL_ARGS) 178 { 179 struct dentry_meta *dm; 180 181 dm = pn->pn_data; 182 sbuf_printf(sb, "%s", (char *)dm->dm_data); 183 return (0); 184 } 185 186 struct dentry * 187 debugfs_create_file(const char *name, umode_t mode, 188 struct dentry *parent, void *data, 189 const struct file_operations *fops) 190 { 191 struct dentry_meta *dm; 192 struct dentry *dnode; 193 struct pfs_node *pnode; 194 int flags; 195 196 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 197 if (dm == NULL) 198 return (NULL); 199 dnode = &dm->dm_dnode; 200 dm->dm_fops = fops; 201 dm->dm_data = data; 202 dm->dm_mode = mode; 203 dm->dm_type = DM_FILE; 204 if (parent != NULL) 205 pnode = parent->d_pfs_node; 206 else 207 pnode = debugfs_root; 208 209 flags = fops->write ? PFS_RDWR : PFS_RD; 210 dnode->d_pfs_node = pfs_create_file(pnode, name, debugfs_fill, 211 debugfs_attr, NULL, debugfs_destroy, flags | PFS_NOWAIT); 212 if (dnode->d_pfs_node == NULL) { 213 free(dm, M_DFSINT); 214 return (NULL); 215 } 216 dnode->d_pfs_node->pn_data = dm; 217 218 return (dnode); 219 } 220 221 struct dentry * 222 debugfs_create_dir(const char *name, struct dentry *parent) 223 { 224 struct dentry_meta *dm; 225 struct dentry *dnode; 226 struct pfs_node *pnode; 227 228 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 229 if (dm == NULL) 230 return (NULL); 231 dnode = &dm->dm_dnode; 232 dm->dm_mode = 0700; 233 dm->dm_type = DM_DIR; 234 if (parent != NULL) 235 pnode = parent->d_pfs_node; 236 else 237 pnode = debugfs_root; 238 239 dnode->d_pfs_node = pfs_create_dir(pnode, name, debugfs_attr, NULL, debugfs_destroy, PFS_RD | PFS_NOWAIT); 240 if (dnode->d_pfs_node == NULL) { 241 free(dm, M_DFSINT); 242 return (NULL); 243 } 244 dnode->d_pfs_node->pn_data = dm; 245 return (dnode); 246 } 247 248 struct dentry * 249 debugfs_create_symlink(const char *name, struct dentry *parent, 250 const char *dest) 251 { 252 struct dentry_meta *dm; 253 struct dentry *dnode; 254 struct pfs_node *pnode; 255 void *data; 256 257 data = strdup_flags(dest, M_DFSINT, M_NOWAIT); 258 if (data == NULL) 259 return (NULL); 260 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 261 if (dm == NULL) 262 goto fail1; 263 dnode = &dm->dm_dnode; 264 dm->dm_mode = 0700; 265 dm->dm_type = DM_SYMLINK; 266 dm->dm_data = data; 267 if (parent != NULL) 268 pnode = parent->d_pfs_node; 269 else 270 pnode = debugfs_root; 271 272 dnode->d_pfs_node = pfs_create_link(pnode, name, &debugfs_fill_data, NULL, NULL, NULL, PFS_NOWAIT); 273 if (dnode->d_pfs_node == NULL) 274 goto fail; 275 dnode->d_pfs_node->pn_data = dm; 276 return (dnode); 277 fail: 278 free(dm, M_DFSINT); 279 fail1: 280 free(data, M_DFSINT); 281 return (NULL); 282 } 283 284 void 285 debugfs_remove(struct dentry *dnode) 286 { 287 if (dnode == NULL) 288 return; 289 290 pfs_destroy(dnode->d_pfs_node); 291 } 292 293 void 294 debugfs_remove_recursive(struct dentry *dnode) 295 { 296 if (dnode == NULL) 297 return; 298 299 pfs_destroy(dnode->d_pfs_node); 300 } 301 302 static int 303 debugfs_init(PFS_INIT_ARGS) 304 { 305 306 debugfs_root = pi->pi_root; 307 308 (void)debugfs_create_symlink("kcov", NULL, "/dev/kcov"); 309 310 return (0); 311 } 312 313 static int 314 debugfs_uninit(PFS_INIT_ARGS) 315 { 316 return (0); 317 } 318 319 #ifdef PR_ALLOW_MOUNT_LINSYSFS 320 PSEUDOFS(debugfs, 1, PR_ALLOW_MOUNT_LINSYSFS); 321 #else 322 PSEUDOFS(debugfs, 1, VFCF_JAIL); 323 #endif 324 MODULE_DEPEND(lindebugfs, linuxkpi, 1, 1, 1); 325