1#include <linux/init.h> 2#include <linux/errno.h> 3#include <linux/kernel.h> 4#include <linux/proc_fs.h> 5#include <linux/types.h> 6#include <asm/ptrace.h> 7#include <asm/uaccess.h> 8 9#define SAMPLE_BUFFER_SIZE 8192 10 11static char* sample_buffer; 12static char* sample_buffer_pos; 13static int prof_running = 0; 14 15void 16cris_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 33static ssize_t 34read_cris_profile(struct file *file, char __user *buf, 35 size_t count, loff_t *ppos) 36{ 37 unsigned long p = *ppos; 38 39 if (p > SAMPLE_BUFFER_SIZE) 40 return 0; 41 42 if (p + count > SAMPLE_BUFFER_SIZE) 43 count = SAMPLE_BUFFER_SIZE - p; 44 if (copy_to_user(buf, sample_buffer + p,count)) 45 return -EFAULT; 46 47 memset(sample_buffer + p, 0, count); 48 *ppos += count; 49 50 return count; 51} 52 53static ssize_t 54write_cris_profile(struct file *file, const char __user *buf, 55 size_t count, loff_t *ppos) 56{ 57 sample_buffer_pos = sample_buffer; 58 memset(sample_buffer, 0, SAMPLE_BUFFER_SIZE); 59} 60 61static const struct file_operations cris_proc_profile_operations = { 62 .read = read_cris_profile, 63 .write = write_cris_profile, 64}; 65 66static int 67__init init_cris_profile(void) 68{ 69 struct proc_dir_entry *entry; 70 71 sample_buffer = kmalloc(SAMPLE_BUFFER_SIZE, GFP_KERNEL); 72 if (!sample_buffer) { 73 return -ENOMEM; 74 } 75 76 sample_buffer_pos = sample_buffer; 77 78 entry = create_proc_entry("system_profile", S_IWUSR | S_IRUGO, NULL); 79 if (entry) { 80 entry->proc_fops = &cris_proc_profile_operations; 81 entry->size = SAMPLE_BUFFER_SIZE; 82 } 83 prof_running = 1; 84 85 return 0; 86} 87 88__initcall(init_cris_profile); 89