1 #include <linux/init.h>
2 #include <linux/errno.h>
3 #include <linux/kernel.h>
4 #include <linux/proc_fs.h>
5 #include <linux/slab.h>
6 #include <linux/types.h>
7 #include <asm/ptrace.h>
8 #include <asm/uaccess.h>
9
10 #define SAMPLE_BUFFER_SIZE 8192
11
12 static char *sample_buffer;
13 static char *sample_buffer_pos;
14 static int prof_running = 0;
15
cris_profile_sample(struct pt_regs * regs)16 void cris_profile_sample(struct pt_regs *regs)
17 {
18 if (!prof_running)
19 return;
20
21 if (user_mode(regs))
22 *(unsigned int*)sample_buffer_pos = current->pid;
23 else
24 *(unsigned int*)sample_buffer_pos = 0;
25
26 *(unsigned int *)(sample_buffer_pos + 4) = instruction_pointer(regs);
27 sample_buffer_pos += 8;
28
29 if (sample_buffer_pos == sample_buffer + SAMPLE_BUFFER_SIZE)
30 sample_buffer_pos = sample_buffer;
31 }
32
33 static ssize_t
read_cris_profile(struct file * file,char __user * buf,size_t count,loff_t * ppos)34 read_cris_profile(struct file *file, char __user *buf,
35 size_t count, loff_t *ppos)
36 {
37 unsigned long p = *ppos;
38 ssize_t ret;
39
40 ret = simple_read_from_buffer(buf, count, ppos, sample_buffer,
41 SAMPLE_BUFFER_SIZE);
42 if (ret < 0)
43 return ret;
44
45 memset(sample_buffer + p, 0, ret);
46
47 return ret;
48 }
49
50 static ssize_t
write_cris_profile(struct file * file,const char __user * buf,size_t count,loff_t * ppos)51 write_cris_profile(struct file *file, const char __user *buf,
52 size_t count, loff_t *ppos)
53 {
54 sample_buffer_pos = sample_buffer;
55 memset(sample_buffer, 0, SAMPLE_BUFFER_SIZE);
56 return count < SAMPLE_BUFFER_SIZE ? count : SAMPLE_BUFFER_SIZE;
57 }
58
59 static const struct file_operations cris_proc_profile_operations = {
60 .read = read_cris_profile,
61 .write = write_cris_profile,
62 .llseek = default_llseek,
63 };
64
init_cris_profile(void)65 static int __init init_cris_profile(void)
66 {
67 struct proc_dir_entry *entry;
68
69 sample_buffer = kmalloc(SAMPLE_BUFFER_SIZE, GFP_KERNEL);
70 if (!sample_buffer) {
71 return -ENOMEM;
72 }
73
74 sample_buffer_pos = sample_buffer;
75
76 entry = proc_create("system_profile", S_IWUSR | S_IRUGO, NULL,
77 &cris_proc_profile_operations);
78 if (entry) {
79 proc_set_size(entry, SAMPLE_BUFFER_SIZE);
80 }
81 prof_running = 1;
82
83 return 0;
84 }
85 __initcall(init_cris_profile);
86
87