86 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			86 lines
		
	
	
		
			1.7 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/types.h>
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#include <asm/ptrace.h>
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#include <asm/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
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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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}
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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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};
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static int
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__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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		entry->size = 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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