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