From 8e4bff4cab0ddac6060645b0715210484d02ff40 Mon Sep 17 00:00:00 2001
From: Yuval Adam <_@yuv.al>
Date: Wed, 30 Aug 2017 08:25:59 +0000
Subject: Initial file dump from open source release

---
 arch/cris/kernel/profile.c | 86 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 86 insertions(+)
 create mode 100644 arch/cris/kernel/profile.c

(limited to 'arch/cris/kernel/profile.c')

diff --git a/arch/cris/kernel/profile.c b/arch/cris/kernel/profile.c
new file mode 100644
index 00000000..cd9f15b9
--- /dev/null
+++ b/arch/cris/kernel/profile.c
@@ -0,0 +1,86 @@
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/proc_fs.h>
+#include <linux/slab.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;
+	ssize_t ret;
+
+	ret = simple_read_from_buffer(buf, count, ppos, sample_buffer,
+						SAMPLE_BUFFER_SIZE);
+	if (ret < 0)
+		return ret;
+
+	memset(sample_buffer + p, 0, ret);
+
+	return ret;
+}
+
+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);
+	return count < SAMPLE_BUFFER_SIZE ? count : SAMPLE_BUFFER_SIZE;
+}
+
+static const struct file_operations cris_proc_profile_operations = {
+	.read		= read_cris_profile,
+	.write		= write_cris_profile,
+	.llseek		= default_llseek,
+};
+
+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) {
+		proc_set_size(entry, SAMPLE_BUFFER_SIZE);
+	}
+	prof_running = 1;
+
+	return 0;
+}
+__initcall(init_cris_profile);
+
-- 
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