llseek: automatically add .llseek fop
[linux-2.6.git] / arch / cris / kernel / profile.c
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
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
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
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
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                 entry->size = SAMPLE_BUFFER_SIZE;
80         }
81         prof_running = 1;
82
83         return 0;
84 }
85 __initcall(init_cris_profile);
86