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/* Copyright (c) 2015, Intel Corporation
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Intel Corporation nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#define _GNU_SOURCE
#include "env_dump.h"
#include <sys/types.h>
#include <pthread.h>
#include <unistd.h>
#include <stdarg.h>
#include <stdlib.h>
#include <dlfcn.h>
#include <link.h>
/* Have a small DB of booleans that will store if we already accounted the
* fd (1) or not yet (0). This DB can hold up to 2048, which is twice the usual
* limit found on Linux.
*/
static pthread_mutex_t fd_mp = PTHREAD_MUTEX_INITIALIZER;
static unsigned long fds[64] = { 0 };
/* get the possibility to call hooks when closing an fd */
static struct fd_close_cb_t {
fd_callback cb;
int fd;
void *user;
} *fd_close_cb;
static size_t fd_close_cb_len;
static inline int
bit_read(int bit)
{
int val;
/* If we go out of the expected range, just give up and say it has been
* reported already!
*/
if (unlikely(bit > sizeof(fds) * 8))
return 1;
val = (fds[bit >> 5] >> (bit & 0x1f)) & 1;
return val;
}
static inline void
bit_write(int bit, int value)
{
int idxh, idxl;
if (unlikely(bit > sizeof(fds) * 8))
return;
idxh = bit >> 5;
idxl = bit & 0x1f;
fds[idxh] = (fds[idxh] & ~(1 << idxl)) | (value << idxl);
}
static ssize_t
get_path_from_fd(int fd, char *buf, size_t bufsiz)
{
/* longest fd path is /proc/4194303/fd/1024 --> 21 chars */
char proc_path[22];
sprintf(proc_path, "/proc/%u/fd/%u", getpid(), fd);
return readlink(proc_path, buf, bufsiz);
}
int
ioctl(int fd, unsigned long int request, ...)
{
int (*orig_ioctl)(int, unsigned long int, ...);
void *arg;
va_list ap;
va_start(ap, request);
arg = va_arg(ap, void *);
/* If it is the first time we see an ioctl on this fd */
pthread_mutex_lock(&fd_mp);
orig_ioctl = _env_dump_resolve_symbol_by_id(SYMB_IOCTL);
if (!bit_read(fd)) {
char path[101];
size_t len = get_path_from_fd(fd, path, sizeof(path));
path[len] = '\0';
if (path[0] == '/')
fprintf(env_file, "IOCTL,%s\n", path);
bit_write(fd, 1);
pthread_mutex_unlock(&fd_mp);
_env_dump_drm_dump_info(path, fd);
} else
pthread_mutex_unlock(&fd_mp);
return orig_ioctl(fd, request, arg);
}
void
_env_dump_close_callback(int fd, fd_callback cb, void *user)
{
int idx = -1, i;
pthread_mutex_lock(&fd_mp);
for (i = 0; i < fd_close_cb_len; i++) {
/* re-use a slot if available */
if (fd_close_cb[i].cb == NULL)
idx = i;
}
if (idx < 0) {
fd_close_cb = realloc(fd_close_cb, sizeof(struct fd_close_cb_t) * (fd_close_cb_len + 1));
/* XXX: just crash if we do not have enough RAM ... */
idx = fd_close_cb_len;
fd_close_cb_len++;
}
fd_close_cb[idx].fd = fd;
fd_close_cb[idx].cb = cb;
fd_close_cb[idx].user = user;
pthread_mutex_unlock(&fd_mp);
}
static void
call_fd_close_callbacks(int fd)
{
int i;
pthread_mutex_lock(&fd_mp);
/* call the callbacks */
for (i = 0; i < fd_close_cb_len; i++) {
/* re-use a slot if available */
if (fd < 0 || fd_close_cb[i].fd == fd) {
fd_callback cb = fd_close_cb[i].cb;
int cb_fd = fd_close_cb[i].fd;
void *cb_user = fd_close_cb[i].user;
fd_close_cb[i].fd = -1;
fd_close_cb[i].cb = NULL;
fd_close_cb[i].user = NULL;
pthread_mutex_unlock(&fd_mp);
cb(cb_fd, cb_user);
pthread_mutex_lock(&fd_mp);
}
}
pthread_mutex_unlock(&fd_mp);
}
int
close(int fd)
{
int (*orig_close)(int);
orig_close = _env_dump_resolve_symbol_by_name("close");
/* call the callbacks */
call_fd_close_callbacks(fd);
pthread_mutex_lock(&fd_mp);
bit_write(fd, 0);
pthread_mutex_unlock(&fd_mp);
return orig_close(fd);
}
void
_env_dump_fd_init()
{
}
void
_env_dump_fd_fini()
{
/* call the callbacks */
call_fd_close_callbacks(-1);
}
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