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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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5e6a0e0527
There is no mutex protection of these state checking for 'stop' and 'detach' which can't guarantee there is no another instance is trying to do same operation. Consider two instances case: Instance1: echo stop > /sys/class/remoteproc/remoteproc0/state Instance2: echo stop > /sys/class/remoteproc/remoteproc0/state The issue is that the instance2 case may success, Or it may fail with -EINVAL, which is uncertain. So move this state checking in rproc_cdev_write() and state_store() for 'stop', 'detach' operation to 'rproc_shutdown' , 'rproc_detach' function under the mutex protection. Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com> Link: https://lore.kernel.org/r/1648434012-16655-3-git-send-email-shengjiu.wang@nxp.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
126 lines
2.9 KiB
C
126 lines
2.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Character device interface driver for Remoteproc framework.
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*
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* Copyright (c) 2020, The Linux Foundation. All rights reserved.
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*/
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#include <linux/cdev.h>
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#include <linux/compat.h>
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#include <linux/fs.h>
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#include <linux/module.h>
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#include <linux/remoteproc.h>
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#include <linux/uaccess.h>
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#include <uapi/linux/remoteproc_cdev.h>
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#include "remoteproc_internal.h"
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#define NUM_RPROC_DEVICES 64
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static dev_t rproc_major;
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static ssize_t rproc_cdev_write(struct file *filp, const char __user *buf, size_t len, loff_t *pos)
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{
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struct rproc *rproc = container_of(filp->f_inode->i_cdev, struct rproc, cdev);
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int ret = 0;
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char cmd[10];
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if (!len || len > sizeof(cmd))
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return -EINVAL;
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ret = copy_from_user(cmd, buf, len);
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if (ret)
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return -EFAULT;
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if (!strncmp(cmd, "start", len)) {
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ret = rproc_boot(rproc);
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} else if (!strncmp(cmd, "stop", len)) {
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ret = rproc_shutdown(rproc);
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} else if (!strncmp(cmd, "detach", len)) {
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ret = rproc_detach(rproc);
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} else {
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dev_err(&rproc->dev, "Unrecognized option\n");
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ret = -EINVAL;
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}
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return ret ? ret : len;
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}
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static long rproc_device_ioctl(struct file *filp, unsigned int ioctl, unsigned long arg)
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{
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struct rproc *rproc = container_of(filp->f_inode->i_cdev, struct rproc, cdev);
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void __user *argp = (void __user *)arg;
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s32 param;
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switch (ioctl) {
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case RPROC_SET_SHUTDOWN_ON_RELEASE:
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if (copy_from_user(¶m, argp, sizeof(s32)))
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return -EFAULT;
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rproc->cdev_put_on_release = !!param;
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break;
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case RPROC_GET_SHUTDOWN_ON_RELEASE:
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param = (s32)rproc->cdev_put_on_release;
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if (copy_to_user(argp, ¶m, sizeof(s32)))
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return -EFAULT;
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break;
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default:
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dev_err(&rproc->dev, "Unsupported ioctl\n");
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return -EINVAL;
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}
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return 0;
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}
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static int rproc_cdev_release(struct inode *inode, struct file *filp)
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{
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struct rproc *rproc = container_of(inode->i_cdev, struct rproc, cdev);
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int ret = 0;
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if (!rproc->cdev_put_on_release)
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return 0;
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if (rproc->state == RPROC_RUNNING)
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rproc_shutdown(rproc);
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else if (rproc->state == RPROC_ATTACHED)
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ret = rproc_detach(rproc);
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return ret;
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}
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static const struct file_operations rproc_fops = {
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.write = rproc_cdev_write,
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.unlocked_ioctl = rproc_device_ioctl,
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.compat_ioctl = compat_ptr_ioctl,
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.release = rproc_cdev_release,
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};
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int rproc_char_device_add(struct rproc *rproc)
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{
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int ret;
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cdev_init(&rproc->cdev, &rproc_fops);
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rproc->cdev.owner = THIS_MODULE;
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rproc->dev.devt = MKDEV(MAJOR(rproc_major), rproc->index);
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cdev_set_parent(&rproc->cdev, &rproc->dev.kobj);
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ret = cdev_add(&rproc->cdev, rproc->dev.devt, 1);
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if (ret < 0)
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dev_err(&rproc->dev, "Failed to add char dev for %s\n", rproc->name);
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return ret;
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}
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void rproc_char_device_remove(struct rproc *rproc)
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{
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cdev_del(&rproc->cdev);
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}
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void __init rproc_init_cdev(void)
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{
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int ret;
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ret = alloc_chrdev_region(&rproc_major, 0, NUM_RPROC_DEVICES, "remoteproc");
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if (ret < 0)
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pr_err("Failed to alloc rproc_cdev region, err %d\n", ret);
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}
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