2 * Copyright © 2018 Broadcom
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice (including the next
12 * paragraph) shall be included in all copies or substantial portions of the
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
27 * Implements wrappers of libc functions to fake having a DRM device that
28 * isn't actually present in the kernel.
31 /* Prevent glibc from defining open64 when we want to alias it. */
32 #undef _FILE_OFFSET_BITS
33 #define _LARGEFILE64_SOURCE
40 #include <sys/ioctl.h>
43 #include <sys/sysmacros.h>
48 #include <c11/threads.h>
49 #include <drm-uapi/drm.h>
52 #include "util/u_debug.h"
55 #define REAL_FUNCTION_POINTER(x) typeof(x) *real_##x
57 static mtx_t shim_lock
= _MTX_INITIALIZER_NP
;
58 struct set
*opendir_set
;
61 /* If /dev/dri doesn't exist, we'll need an arbitrary pointer that wouldn't be
62 * returned by any other opendir() call so we can return just our fake node.
64 DIR *fake_dev_dri
= (void *)&opendir_set
;
66 /* XXX: implement REAL_FUNCTION_POINTER(close); */
67 REAL_FUNCTION_POINTER(closedir
);
68 REAL_FUNCTION_POINTER(dup
);
69 REAL_FUNCTION_POINTER(fcntl
);
70 REAL_FUNCTION_POINTER(fopen
);
71 REAL_FUNCTION_POINTER(ioctl
);
72 REAL_FUNCTION_POINTER(mmap
);
73 REAL_FUNCTION_POINTER(open
);
74 REAL_FUNCTION_POINTER(opendir
);
75 REAL_FUNCTION_POINTER(readdir
);
76 REAL_FUNCTION_POINTER(readdir64
);
77 REAL_FUNCTION_POINTER(readlink
);
78 REAL_FUNCTION_POINTER(realpath
);
79 REAL_FUNCTION_POINTER(__xstat
);
80 REAL_FUNCTION_POINTER(__xstat64
);
81 REAL_FUNCTION_POINTER(__fxstat
);
82 REAL_FUNCTION_POINTER(__fxstat64
);
84 /* Full path of /dev/dri/renderD* */
85 static char *render_node_path
;
87 static char *render_node_dirent_name
;
88 /* /sys/dev/char/major:minor/device */
89 static char *device_path
;
90 /* /sys/dev/char/major:minor/device/subsystem */
91 static char *subsystem_path
;
92 int render_node_minor
= -1;
94 struct file_override
{
98 static struct file_override file_overrides
[10];
99 static int file_overrides_count
;
101 /* Come up with a filename for a render node that doesn't actually exist on
105 get_dri_render_node_minor(void)
107 for (int i
= 0; i
< 10; i
++) {
109 asprintf(&render_node_dirent_name
, "renderD%d", minor
);
110 asprintf(&render_node_path
, "/dev/dri/%s",
111 render_node_dirent_name
);
113 if (stat(render_node_path
, &st
) == -1) {
115 render_node_minor
= minor
;
120 fprintf(stderr
, "Couldn't find a spare render node slot\n");
123 static void *get_function_pointer(const char *name
)
125 void *func
= dlsym(RTLD_NEXT
, name
);
127 fprintf(stderr
, "Failed to resolve %s\n", name
);
133 #define GET_FUNCTION_POINTER(x) real_##x = get_function_pointer(#x)
136 drm_shim_override_file(const char *contents
, const char *path_format
, ...)
138 assert(file_overrides_count
< ARRAY_SIZE(file_overrides
));
142 va_start(ap
, path_format
);
143 vasprintf(&path
, path_format
, ap
);
146 struct file_override
*override
= &file_overrides
[file_overrides_count
++];
147 override
->path
= path
;
148 override
->contents
= strdup(contents
);
154 _mesa_set_destroy(opendir_set
, NULL
);
155 free(render_node_path
);
156 free(render_node_dirent_name
);
157 free(subsystem_path
);
160 /* Initialization, which will be called from the first general library call
161 * that might need to be wrapped with the shim.
166 static bool inited
= false;
167 drm_shim_debug
= debug_get_bool_option("DRM_SHIM_DEBUG", false);
169 /* We can't lock this, because we recurse during initialization. */
173 /* This comes first (and we're locked), to make sure we don't recurse
174 * during initialization.
178 opendir_set
= _mesa_set_create(NULL
,
180 _mesa_key_string_equal
);
182 GET_FUNCTION_POINTER(closedir
);
183 GET_FUNCTION_POINTER(dup
);
184 GET_FUNCTION_POINTER(fcntl
);
185 GET_FUNCTION_POINTER(fopen
);
186 GET_FUNCTION_POINTER(ioctl
);
187 GET_FUNCTION_POINTER(mmap
);
188 GET_FUNCTION_POINTER(open
);
189 GET_FUNCTION_POINTER(opendir
);
190 GET_FUNCTION_POINTER(readdir
);
191 GET_FUNCTION_POINTER(readdir64
);
192 GET_FUNCTION_POINTER(readlink
);
193 GET_FUNCTION_POINTER(realpath
);
194 GET_FUNCTION_POINTER(__xstat
);
195 GET_FUNCTION_POINTER(__xstat64
);
196 GET_FUNCTION_POINTER(__fxstat
);
197 GET_FUNCTION_POINTER(__fxstat64
);
199 get_dri_render_node_minor();
201 if (drm_shim_debug
) {
202 fprintf(stderr
, "Initializing DRM shim on %s\n",
206 asprintf(&device_path
,
207 "/sys/dev/char/%d:%d/device",
208 DRM_MAJOR
, render_node_minor
);
210 asprintf(&subsystem_path
,
211 "/sys/dev/char/%d:%d/device/subsystem",
212 DRM_MAJOR
, render_node_minor
);
214 drm_shim_device_init();
216 atexit(destroy_shim
);
219 /* Override libdrm's reading of various sysfs files for device enumeration. */
220 PUBLIC
FILE *fopen(const char *path
, const char *mode
)
224 for (int i
= 0; i
< file_overrides_count
; i
++) {
225 if (strcmp(file_overrides
[i
].path
, path
) == 0) {
228 write(fds
[1], file_overrides
[i
].contents
,
229 strlen(file_overrides
[i
].contents
));
231 return fdopen(fds
[0], "r");
235 return real_fopen(path
, mode
);
237 PUBLIC
FILE *fopen64(const char *path
, const char *mode
)
238 __attribute__((alias("fopen")));
240 /* Intercepts open(render_node_path) to redirect it to the simulator. */
241 PUBLIC
int open(const char *path
, int flags
, ...)
247 mode_t mode
= va_arg(ap
, mode_t
);
250 if (strcmp(path
, render_node_path
) != 0)
251 return real_open(path
, flags
, mode
);
253 int fd
= real_open("/dev/null", O_RDWR
, 0);
255 drm_shim_fd_register(fd
, NULL
);
259 PUBLIC
int open64(const char*, int, ...) __attribute__((alias("open")));
261 /* Fakes stat to return character device stuff for our fake render node. */
262 PUBLIC
int __xstat(int ver
, const char *path
, struct stat
*st
)
266 /* Note: call real stat if we're in the process of probing for a free
269 if (render_node_minor
== -1)
270 return real___xstat(ver
, path
, st
);
272 /* Fool libdrm's probe of whether the /sys dir for this char dev is
275 char *sys_dev_drm_dir
;
276 asprintf(&sys_dev_drm_dir
, "/sys/dev/char/%d:%d/device/drm",
277 DRM_MAJOR
, render_node_minor
);
278 if (strcmp(path
, sys_dev_drm_dir
) == 0) {
279 free(sys_dev_drm_dir
);
282 free(sys_dev_drm_dir
);
284 if (strcmp(path
, render_node_path
) != 0)
285 return real___xstat(ver
, path
, st
);
287 memset(st
, 0, sizeof(*st
));
288 st
->st_rdev
= makedev(DRM_MAJOR
, render_node_minor
);
289 st
->st_mode
= S_IFCHR
;
294 /* Fakes stat to return character device stuff for our fake render node. */
295 PUBLIC
int __xstat64(int ver
, const char *path
, struct stat64
*st
)
299 /* Note: call real stat if we're in the process of probing for a free
302 if (render_node_minor
== -1)
303 return real___xstat64(ver
, path
, st
);
305 /* Fool libdrm's probe of whether the /sys dir for this char dev is
308 char *sys_dev_drm_dir
;
309 asprintf(&sys_dev_drm_dir
, "/sys/dev/char/%d:%d/device/drm",
310 DRM_MAJOR
, render_node_minor
);
311 if (strcmp(path
, sys_dev_drm_dir
) == 0) {
312 free(sys_dev_drm_dir
);
315 free(sys_dev_drm_dir
);
317 if (strcmp(path
, render_node_path
) != 0)
318 return real___xstat64(ver
, path
, st
);
320 memset(st
, 0, sizeof(*st
));
321 st
->st_rdev
= makedev(DRM_MAJOR
, render_node_minor
);
322 st
->st_mode
= S_IFCHR
;
327 /* Fakes fstat to return character device stuff for our fake render node. */
328 PUBLIC
int __fxstat(int ver
, int fd
, struct stat
*st
)
332 struct shim_fd
*shim_fd
= drm_shim_fd_lookup(fd
);
335 return real___fxstat(ver
, fd
, st
);
337 memset(st
, 0, sizeof(*st
));
338 st
->st_rdev
= makedev(DRM_MAJOR
, render_node_minor
);
339 st
->st_mode
= S_IFCHR
;
344 PUBLIC
int __fxstat64(int ver
, int fd
, struct stat64
*st
)
348 struct shim_fd
*shim_fd
= drm_shim_fd_lookup(fd
);
351 return real___fxstat64(ver
, fd
, st
);
353 memset(st
, 0, sizeof(*st
));
354 st
->st_rdev
= makedev(DRM_MAJOR
, render_node_minor
);
355 st
->st_mode
= S_IFCHR
;
360 /* Tracks if the opendir was on /dev/dri. */
362 opendir(const char *name
)
366 DIR *dir
= real_opendir(name
);
367 if (strcmp(name
, "/dev/dri") == 0) {
369 /* If /dev/dri didn't exist, we still want to be able to return our
370 * fake /dev/dri/render* even though we probably can't
371 * mkdir("/dev/dri"). Return a fake DIR pointer for that.
376 mtx_lock(&shim_lock
);
377 _mesa_set_add(opendir_set
, dir
);
378 mtx_unlock(&shim_lock
);
384 /* If we've reached the end of the real directory list and we're
385 * looking at /dev/dri, add our render node to the list.
387 PUBLIC
struct dirent
*
392 struct dirent
*ent
= NULL
;
394 if (dir
!= fake_dev_dri
)
395 ent
= real_readdir(dir
);
396 static struct dirent render_node_dirent
= { 0 };
399 mtx_lock(&shim_lock
);
400 if (_mesa_set_search(opendir_set
, dir
)) {
401 strcpy(render_node_dirent
.d_name
,
402 render_node_dirent_name
);
403 ent
= &render_node_dirent
;
404 _mesa_set_remove_key(opendir_set
, dir
);
406 mtx_unlock(&shim_lock
);
412 /* If we've reached the end of the real directory list and we're
413 * looking at /dev/dri, add our render node to the list.
415 PUBLIC
struct dirent64
*
420 struct dirent64
*ent
= NULL
;
421 if (dir
!= fake_dev_dri
)
422 ent
= real_readdir64(dir
);
423 static struct dirent64 render_node_dirent
= { 0 };
426 mtx_lock(&shim_lock
);
427 if (_mesa_set_search(opendir_set
, dir
)) {
428 strcpy(render_node_dirent
.d_name
,
429 render_node_dirent_name
);
430 ent
= &render_node_dirent
;
431 _mesa_set_remove_key(opendir_set
, dir
);
433 mtx_unlock(&shim_lock
);
439 /* Cleans up tracking of opendir("/dev/dri") */
445 mtx_lock(&shim_lock
);
446 _mesa_set_remove_key(opendir_set
, dir
);
447 mtx_unlock(&shim_lock
);
449 if (dir
!= fake_dev_dri
)
450 return real_closedir(dir
);
455 /* Handles libdrm's readlink to figure out what kind of device we have. */
457 readlink(const char *path
, char *buf
, size_t size
)
461 if (strcmp(path
, subsystem_path
) != 0)
462 return real_readlink(path
, buf
, size
);
464 static const struct {
468 { "/pci", DRM_BUS_PCI
},
469 { "/usb", DRM_BUS_USB
},
470 { "/platform", DRM_BUS_PLATFORM
},
471 { "/spi", DRM_BUS_PLATFORM
},
472 { "/host1x", DRM_BUS_HOST1X
},
475 for (uint32_t i
= 0; i
< ARRAY_SIZE(bus_types
); i
++) {
476 if (bus_types
[i
].bus_type
!= shim_device
.bus_type
)
479 strncpy(buf
, bus_types
[i
].name
, size
);
484 return strlen(buf
) + 1;
487 /* Handles libdrm's realpath to figure out what kind of device we have. */
489 realpath(const char *path
, char *resolved_path
)
493 if (strcmp(path
, device_path
) != 0)
494 return real_realpath(path
, resolved_path
);
496 strcpy(resolved_path
, path
);
498 return resolved_path
;
501 /* Main entrypoint to DRM drivers: the ioctl syscall. We send all ioctls on
502 * our DRM fd to drm_shim_ioctl().
505 ioctl(int fd
, unsigned long request
, ...)
510 va_start(ap
, request
);
511 void *arg
= va_arg(ap
, void *);
514 struct shim_fd
*shim_fd
= drm_shim_fd_lookup(fd
);
516 return real_ioctl(fd
, request
, arg
);
518 return drm_shim_ioctl(fd
, request
, arg
);
521 /* Gallium uses this to dup the incoming fd on gbm screen creation */
523 fcntl(int fd
, int cmd
, ...)
527 struct shim_fd
*shim_fd
= drm_shim_fd_lookup(fd
);
531 void *arg
= va_arg(ap
, void *);
534 int ret
= real_fcntl(fd
, cmd
, arg
);
536 if (shim_fd
&& (cmd
== F_DUPFD
|| cmd
== F_DUPFD_CLOEXEC
))
537 drm_shim_fd_register(ret
, shim_fd
);
541 PUBLIC
int fcntl64(int, int, ...)
542 __attribute__((alias("fcntl")));
544 /* I wrote this when trying to fix gallium screen creation, leaving it around
545 * since it's probably good to have.
552 int ret
= real_dup(fd
);
554 struct shim_fd
*shim_fd
= drm_shim_fd_lookup(fd
);
555 if (shim_fd
&& ret
>= 0)
556 drm_shim_fd_register(ret
, shim_fd
);
562 mmap(void *addr
, size_t length
, int prot
, int flags
, int fd
, off_t offset
)
566 struct shim_fd
*shim_fd
= drm_shim_fd_lookup(fd
);
568 return drm_shim_mmap(shim_fd
, length
, prot
, flags
, fd
, offset
);
570 return real_mmap(addr
, length
, prot
, flags
, fd
, offset
);
572 PUBLIC
void *mmap64(void*, size_t, int, int, int, off_t
)
573 __attribute__((alias("mmap")));