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#include <linux/init.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/proc_fs.h>
#include <linux/types.h>
#include <asm/ptrace.h>
#include <asm/uaccess.h>
#define SAMPLE_BUFFER_SIZE 8192
static char* sample_buffer;
static char* sample_buffer_pos;
static int prof_running = 0;
void
cris_profile_sample(struct pt_regs* regs)
{
if (!prof_running)
return;
if (user_mode(regs))
*(unsigned int*)sample_buffer_pos = current->pid;
else
*(unsigned int*)sample_buffer_pos = 0;
*(unsigned int*)(sample_buffer_pos + 4) = instruction_pointer(regs);
sample_buffer_pos += 8;
if (sample_buffer_pos == sample_buffer + SAMPLE_BUFFER_SIZE)
sample_buffer_pos = sample_buffer;
}
static ssize_t
read_cris_profile(struct file *file, char __user *buf,
size_t count, loff_t *ppos)
{
unsigned long p = *ppos;
if (p > SAMPLE_BUFFER_SIZE)
return 0;
if (p + count > SAMPLE_BUFFER_SIZE)
count = SAMPLE_BUFFER_SIZE - p;
if (copy_to_user(buf, sample_buffer + p,count))
return -EFAULT;
memset(sample_buffer + p, 0, count);
*ppos += count;
return count;
}
static ssize_t
write_cris_profile(struct file *file, const char __user *buf,
size_t count, loff_t *ppos)
{
sample_buffer_pos = sample_buffer;
memset(sample_buffer, 0, SAMPLE_BUFFER_SIZE);
}
static const struct file_operations cris_proc_profile_operations = {
.read = read_cris_profile,
.write = write_cris_profile,
};
static int
__init init_cris_profile(void)
{
struct proc_dir_entry *entry;
sample_buffer = kmalloc(SAMPLE_BUFFER_SIZE, GFP_KERNEL);
if (!sample_buffer) {
return -ENOMEM;
}
sample_buffer_pos = sample_buffer;
entry = proc_create("system_profile", S_IWUSR | S_IRUGO, NULL,
&cris_proc_profile_operations);
if (entry) {
entry->size = SAMPLE_BUFFER_SIZE;
}
prof_running = 1;
return 0;
}
__initcall(init_cris_profile);
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