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 buf = uio->uio_iov[0].iov_base; 134 len = min(uio->uio_iov[0].iov_len, uio->uio_resid); 135 off = 0; 136 lf.private_data = NULL; 137 rc = d->dm_fops->open(&vn, &lf); 138 if (rc < 0) { 139 #ifdef INVARIANTS 140 printf("%s:%d open failed with %d\n", __FUNCTION__, __LINE__, rc); 141 #endif 142 return (-rc); 143 } 144 sf = lf.private_data; 145 sf->buf = sb; 146 if (uio->uio_rw == UIO_READ) { 147 if (d->dm_fops->read) 148 rc = d->dm_fops->read(&lf, NULL, len, &off); 149 else 150 rc = ENODEV; 151 } else { 152 if (d->dm_fops->write) 153 rc = d->dm_fops->write(&lf, buf, len, &off); 154 else 155 rc = ENODEV; 156 } 157 if (d->dm_fops->release) 158 d->dm_fops->release(&vn, &lf); 159 else 160 single_release(&vn, &lf); 161 162 if (rc < 0) { 163 #ifdef INVARIANTS 164 printf("%s:%d read/write failed with %d\n", __FUNCTION__, __LINE__, rc); 165 #endif 166 return (-rc); 167 } 168 return (0); 169 } 170 171 static int 172 debugfs_fill_data(PFS_FILL_ARGS) 173 { 174 struct dentry_meta *dm; 175 176 dm = pn->pn_data; 177 sbuf_printf(sb, "%s", (char *)dm->dm_data); 178 return (0); 179 } 180 181 struct dentry * 182 debugfs_create_file(const char *name, umode_t mode, 183 struct dentry *parent, void *data, 184 const struct file_operations *fops) 185 { 186 struct dentry_meta *dm; 187 struct dentry *dnode; 188 struct pfs_node *pnode; 189 int flags; 190 191 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 192 if (dm == NULL) 193 return (NULL); 194 dnode = &dm->dm_dnode; 195 dm->dm_fops = fops; 196 dm->dm_data = data; 197 dm->dm_mode = mode; 198 dm->dm_type = DM_FILE; 199 if (parent != NULL) 200 pnode = parent->d_pfs_node; 201 else 202 pnode = debugfs_root; 203 204 flags = fops->write ? PFS_RDWR : PFS_RD; 205 dnode->d_pfs_node = pfs_create_file(pnode, name, debugfs_fill, 206 debugfs_attr, NULL, debugfs_destroy, flags | PFS_NOWAIT); 207 if (dnode->d_pfs_node == NULL) { 208 free(dm, M_DFSINT); 209 return (NULL); 210 } 211 dnode->d_pfs_node->pn_data = dm; 212 213 return (dnode); 214 } 215 216 struct dentry * 217 debugfs_create_dir(const char *name, struct dentry *parent) 218 { 219 struct dentry_meta *dm; 220 struct dentry *dnode; 221 struct pfs_node *pnode; 222 223 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 224 if (dm == NULL) 225 return (NULL); 226 dnode = &dm->dm_dnode; 227 dm->dm_mode = 0700; 228 dm->dm_type = DM_DIR; 229 if (parent != NULL) 230 pnode = parent->d_pfs_node; 231 else 232 pnode = debugfs_root; 233 234 dnode->d_pfs_node = pfs_create_dir(pnode, name, debugfs_attr, NULL, debugfs_destroy, PFS_RD | PFS_NOWAIT); 235 if (dnode->d_pfs_node == NULL) { 236 free(dm, M_DFSINT); 237 return (NULL); 238 } 239 dnode->d_pfs_node->pn_data = dm; 240 return (dnode); 241 } 242 243 struct dentry * 244 debugfs_create_symlink(const char *name, struct dentry *parent, 245 const char *dest) 246 { 247 struct dentry_meta *dm; 248 struct dentry *dnode; 249 struct pfs_node *pnode; 250 void *data; 251 252 data = strdup_flags(dest, M_DFSINT, M_NOWAIT); 253 if (data == NULL) 254 return (NULL); 255 dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO); 256 if (dm == NULL) 257 goto fail1; 258 dnode = &dm->dm_dnode; 259 dm->dm_mode = 0700; 260 dm->dm_type = DM_SYMLINK; 261 dm->dm_data = data; 262 if (parent != NULL) 263 pnode = parent->d_pfs_node; 264 else 265 pnode = debugfs_root; 266 267 dnode->d_pfs_node = pfs_create_link(pnode, name, &debugfs_fill_data, NULL, NULL, NULL, PFS_NOWAIT); 268 if (dnode->d_pfs_node == NULL) 269 goto fail; 270 dnode->d_pfs_node->pn_data = dm; 271 return (dnode); 272 fail: 273 free(dm, M_DFSINT); 274 fail1: 275 free(data, M_DFSINT); 276 return (NULL); 277 } 278 279 void 280 debugfs_remove(struct dentry *dnode) 281 { 282 if (dnode == NULL) 283 return; 284 285 pfs_destroy(dnode->d_pfs_node); 286 } 287 288 void 289 debugfs_remove_recursive(struct dentry *dnode) 290 { 291 if (dnode == NULL) 292 return; 293 294 pfs_destroy(dnode->d_pfs_node); 295 } 296 297 static int 298 debugfs_init(PFS_INIT_ARGS) 299 { 300 301 debugfs_root = pi->pi_root; 302 303 (void)debugfs_create_symlink("kcov", NULL, "/dev/kcov"); 304 305 return (0); 306 } 307 308 static int 309 debugfs_uninit(PFS_INIT_ARGS) 310 { 311 return (0); 312 } 313 314 #ifdef PR_ALLOW_MOUNT_LINSYSFS 315 PSEUDOFS(debugfs, 1, PR_ALLOW_MOUNT_LINSYSFS); 316 #else 317 PSEUDOFS(debugfs, 1, VFCF_JAIL); 318 #endif 319 MODULE_DEPEND(lindebugfs, linuxkpi, 1, 1, 1); 320