cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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fault_inject.c (2221B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * fault injection support for nvme.
      4 *
      5 * Copyright (c) 2018, Oracle and/or its affiliates
      6 */
      7
      8#include <linux/moduleparam.h>
      9#include "nvme.h"
     10
     11static DECLARE_FAULT_ATTR(fail_default_attr);
     12/* optional fault injection attributes boot time option:
     13 * nvme_core.fail_request=<interval>,<probability>,<space>,<times>
     14 */
     15static char *fail_request;
     16module_param(fail_request, charp, 0000);
     17
     18void nvme_fault_inject_init(struct nvme_fault_inject *fault_inj,
     19			    const char *dev_name)
     20{
     21	struct dentry *dir, *parent;
     22	struct fault_attr *attr = &fault_inj->attr;
     23
     24	/* set default fault injection attribute */
     25	if (fail_request)
     26		setup_fault_attr(&fail_default_attr, fail_request);
     27
     28	/* create debugfs directory and attribute */
     29	parent = debugfs_create_dir(dev_name, NULL);
     30	if (!parent) {
     31		pr_warn("%s: failed to create debugfs directory\n", dev_name);
     32		return;
     33	}
     34
     35	*attr = fail_default_attr;
     36	dir = fault_create_debugfs_attr("fault_inject", parent, attr);
     37	if (IS_ERR(dir)) {
     38		pr_warn("%s: failed to create debugfs attr\n", dev_name);
     39		debugfs_remove_recursive(parent);
     40		return;
     41	}
     42	fault_inj->parent = parent;
     43
     44	/* create debugfs for status code and dont_retry */
     45	fault_inj->status = NVME_SC_INVALID_OPCODE;
     46	fault_inj->dont_retry = true;
     47	debugfs_create_x16("status", 0600, dir,	&fault_inj->status);
     48	debugfs_create_bool("dont_retry", 0600, dir, &fault_inj->dont_retry);
     49}
     50
     51void nvme_fault_inject_fini(struct nvme_fault_inject *fault_inject)
     52{
     53	/* remove debugfs directories */
     54	debugfs_remove_recursive(fault_inject->parent);
     55}
     56
     57void nvme_should_fail(struct request *req)
     58{
     59	struct gendisk *disk = req->q->disk;
     60	struct nvme_fault_inject *fault_inject = NULL;
     61	u16 status;
     62
     63	if (disk) {
     64		struct nvme_ns *ns = disk->private_data;
     65
     66		if (ns)
     67			fault_inject = &ns->fault_inject;
     68		else
     69			WARN_ONCE(1, "No namespace found for request\n");
     70	} else {
     71		fault_inject = &nvme_req(req)->ctrl->fault_inject;
     72	}
     73
     74	if (fault_inject && should_fail(&fault_inject->attr, 1)) {
     75		/* inject status code and DNR bit */
     76		status = fault_inject->status;
     77		if (fault_inject->dont_retry)
     78			status |= NVME_SC_DNR;
     79		nvme_req(req)->status =	status;
     80	}
     81}
     82EXPORT_SYMBOL_GPL(nvme_should_fail);