9c92ab6191
Based on 1 normalized pattern(s): this software is licensed under the terms of the gnu general public license version 2 as published by the free software foundation and may be copied distributed and modified under those terms this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 285 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Alexios Zavras <alexios.zavras@intel.com> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141900.642774971@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
149 lines
3.2 KiB
C
149 lines
3.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright 2012 Google, Inc.
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*/
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#include <linux/kernel.h>
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#include <linux/compiler.h>
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#include <linux/irqflags.h>
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#include <linux/percpu.h>
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#include <linux/smp.h>
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#include <linux/atomic.h>
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#include <linux/types.h>
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#include <linux/mutex.h>
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#include <linux/ftrace.h>
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#include <linux/fs.h>
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#include <linux/debugfs.h>
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#include <linux/err.h>
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#include <linux/cache.h>
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#include <asm/barrier.h>
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#include "internal.h"
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/* This doesn't need to be atomic: speed is chosen over correctness here. */
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static u64 pstore_ftrace_stamp;
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static void notrace pstore_ftrace_call(unsigned long ip,
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unsigned long parent_ip,
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struct ftrace_ops *op,
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struct pt_regs *regs)
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{
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unsigned long flags;
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struct pstore_ftrace_record rec = {};
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struct pstore_record record = {
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.type = PSTORE_TYPE_FTRACE,
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.buf = (char *)&rec,
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.size = sizeof(rec),
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.psi = psinfo,
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};
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if (unlikely(oops_in_progress))
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return;
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local_irq_save(flags);
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rec.ip = ip;
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rec.parent_ip = parent_ip;
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pstore_ftrace_write_timestamp(&rec, pstore_ftrace_stamp++);
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pstore_ftrace_encode_cpu(&rec, raw_smp_processor_id());
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psinfo->write(&record);
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local_irq_restore(flags);
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}
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static struct ftrace_ops pstore_ftrace_ops __read_mostly = {
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.func = pstore_ftrace_call,
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};
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static DEFINE_MUTEX(pstore_ftrace_lock);
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static bool pstore_ftrace_enabled;
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static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf,
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size_t count, loff_t *ppos)
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{
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u8 on;
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ssize_t ret;
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ret = kstrtou8_from_user(buf, count, 2, &on);
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if (ret)
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return ret;
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mutex_lock(&pstore_ftrace_lock);
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if (!on ^ pstore_ftrace_enabled)
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goto out;
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if (on) {
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ftrace_ops_set_global_filter(&pstore_ftrace_ops);
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ret = register_ftrace_function(&pstore_ftrace_ops);
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} else {
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ret = unregister_ftrace_function(&pstore_ftrace_ops);
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}
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if (ret) {
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pr_err("%s: unable to %sregister ftrace ops: %zd\n",
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__func__, on ? "" : "un", ret);
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goto err;
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}
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pstore_ftrace_enabled = on;
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out:
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ret = count;
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err:
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mutex_unlock(&pstore_ftrace_lock);
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return ret;
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}
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static ssize_t pstore_ftrace_knob_read(struct file *f, char __user *buf,
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size_t count, loff_t *ppos)
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{
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char val[] = { '0' + pstore_ftrace_enabled, '\n' };
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return simple_read_from_buffer(buf, count, ppos, val, sizeof(val));
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}
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static const struct file_operations pstore_knob_fops = {
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.open = simple_open,
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.read = pstore_ftrace_knob_read,
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.write = pstore_ftrace_knob_write,
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};
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static struct dentry *pstore_ftrace_dir;
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void pstore_register_ftrace(void)
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{
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struct dentry *file;
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if (!psinfo->write)
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return;
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pstore_ftrace_dir = debugfs_create_dir("pstore", NULL);
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if (!pstore_ftrace_dir) {
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pr_err("%s: unable to create pstore directory\n", __func__);
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return;
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}
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file = debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir,
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NULL, &pstore_knob_fops);
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if (!file) {
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pr_err("%s: unable to create record_ftrace file\n", __func__);
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goto err_file;
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}
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return;
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err_file:
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debugfs_remove(pstore_ftrace_dir);
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}
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void pstore_unregister_ftrace(void)
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{
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mutex_lock(&pstore_ftrace_lock);
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if (pstore_ftrace_enabled) {
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unregister_ftrace_function(&pstore_ftrace_ops);
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pstore_ftrace_enabled = false;
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}
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mutex_unlock(&pstore_ftrace_lock);
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debugfs_remove_recursive(pstore_ftrace_dir);
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}
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