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 lf.private_data = NULL; 143 rc = d->dm_fops->open(&vn, &lf); 144 if (rc < 0) { 145 #ifdef INVARIANTS 146 printf("%s:%d open failed with %d\n", __FUNCTION__, __LINE__, rc); 147 #endif 148 return (-rc); 149 } 150 sf = lf.private_data; 151 sf->buf = sb; 152 if (uio->uio_rw == UIO_READ) { 153 if (d->dm_fops->read) 154 rc = d->dm_fops->read(&lf, NULL, len, &off); 155 else 156 rc = ENODEV; 157 } else { 158 if (d->dm_fops->write) 159 rc = d->dm_fops->write(&lf, buf, len, &off); 160 else 161 rc = ENODEV; 162 } 163 if (d->dm_fops->release) 164 d->dm_fops->release(&vn, &lf); 165 else 166 single_release(&vn, &lf); 167 168 if (rc < 0) { 169 #ifdef INVARIANTS 170 printf("%s:%d read/write failed with %d\n", __FUNCTION__, __LINE__, rc); 171 #endif 172 return (-rc); 173 } 174 return (0); 175 } 176 177 static int 178 debugfs_fill_data(PFS_FILL_ARGS) 179 { 180 struct dentry_meta *dm; 181 182 dm = pn->pn_data; 183 sbuf_printf(sb, "%s", (char *)dm->dm_data); 184 return (0); 185 } 186 187 struct dentry * 188 debugfs_create_file(const char *name, umode_t mode, 189 struct dentry *parent, void *data, 190 const struct file_operations *fops) 191 { 192 struct dentry_meta *dm; 193 struct dentry *dnode; 194 struct pfs_node *pnode; 195 int flags; 196 197 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 198 if (dm == NULL) 199 return (NULL); 200 dnode = &dm->dm_dnode; 201 dm->dm_fops = fops; 202 dm->dm_data = data; 203 dm->dm_mode = mode; 204 dm->dm_type = DM_FILE; 205 if (parent != NULL) 206 pnode = parent->d_pfs_node; 207 else 208 pnode = debugfs_root; 209 210 flags = fops->write ? PFS_RDWR : PFS_RD; 211 dnode->d_pfs_node = pfs_create_file(pnode, name, debugfs_fill, 212 debugfs_attr, NULL, debugfs_destroy, flags | PFS_NOWAIT); 213 if (dnode->d_pfs_node == NULL) { 214 free(dm, M_DFSINT); 215 return (NULL); 216 } 217 dnode->d_pfs_node->pn_data = dm; 218 219 return (dnode); 220 } 221 222 struct dentry * 223 debugfs_create_dir(const char *name, struct dentry *parent) 224 { 225 struct dentry_meta *dm; 226 struct dentry *dnode; 227 struct pfs_node *pnode; 228 229 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 230 if (dm == NULL) 231 return (NULL); 232 dnode = &dm->dm_dnode; 233 dm->dm_mode = 0700; 234 dm->dm_type = DM_DIR; 235 if (parent != NULL) 236 pnode = parent->d_pfs_node; 237 else 238 pnode = debugfs_root; 239 240 dnode->d_pfs_node = pfs_create_dir(pnode, name, debugfs_attr, NULL, debugfs_destroy, PFS_RD | PFS_NOWAIT); 241 if (dnode->d_pfs_node == NULL) { 242 free(dm, M_DFSINT); 243 return (NULL); 244 } 245 dnode->d_pfs_node->pn_data = dm; 246 return (dnode); 247 } 248 249 struct dentry * 250 debugfs_create_symlink(const char *name, struct dentry *parent, 251 const char *dest) 252 { 253 struct dentry_meta *dm; 254 struct dentry *dnode; 255 struct pfs_node *pnode; 256 void *data; 257 258 data = strdup_flags(dest, M_DFSINT, M_NOWAIT); 259 if (data == NULL) 260 return (NULL); 261 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 262 if (dm == NULL) 263 goto fail1; 264 dnode = &dm->dm_dnode; 265 dm->dm_mode = 0700; 266 dm->dm_type = DM_SYMLINK; 267 dm->dm_data = data; 268 if (parent != NULL) 269 pnode = parent->d_pfs_node; 270 else 271 pnode = debugfs_root; 272 273 dnode->d_pfs_node = pfs_create_link(pnode, name, &debugfs_fill_data, NULL, NULL, NULL, PFS_NOWAIT); 274 if (dnode->d_pfs_node == NULL) 275 goto fail; 276 dnode->d_pfs_node->pn_data = dm; 277 return (dnode); 278 fail: 279 free(dm, M_DFSINT); 280 fail1: 281 free(data, M_DFSINT); 282 return (NULL); 283 } 284 285 void 286 debugfs_remove(struct dentry *dnode) 287 { 288 if (dnode == NULL) 289 return; 290 291 pfs_destroy(dnode->d_pfs_node); 292 } 293 294 void 295 debugfs_remove_recursive(struct dentry *dnode) 296 { 297 if (dnode == NULL) 298 return; 299 300 pfs_destroy(dnode->d_pfs_node); 301 } 302 303 static int 304 debugfs_init(PFS_INIT_ARGS) 305 { 306 307 debugfs_root = pi->pi_root; 308 309 (void)debugfs_create_symlink("kcov", NULL, "/dev/kcov"); 310 311 return (0); 312 } 313 314 static int 315 debugfs_uninit(PFS_INIT_ARGS) 316 { 317 return (0); 318 } 319 320 #ifdef PR_ALLOW_MOUNT_LINSYSFS 321 PSEUDOFS(debugfs, 1, PR_ALLOW_MOUNT_LINSYSFS); 322 #else 323 PSEUDOFS(debugfs, 1, VFCF_JAIL); 324 #endif 325 MODULE_DEPEND(lindebugfs, linuxkpi, 1, 1, 1); 326