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b61b8bba18
When the last CPU in an rdt_domain goes offline, its rdt_domain struct gets freed. Current pseudo-locking code is unaware of this scenario and tries to dereference the freed structure in a few places. Add checks to prevent pseudo-locking code from doing this. While further work is needed to seamlessly restore resource groups (not just pseudo-locking) to their configuration when the domain is brought back online, the immediate issue of invalid pointers is addressed here. Fixes:f4e80d67a5
("x86/intel_rdt: Resctrl files reflect pseudo-locked information") Fixes:443810fe61
("x86/intel_rdt: Create debugfs files for pseudo-locking testing") Fixes:746e08590b
("x86/intel_rdt: Create character device exposing pseudo-locked region") Fixes:33dc3e410a
("x86/intel_rdt: Make CPU information accessible for pseudo-locked regions") Signed-off-by: Jithu Joseph <jithu.joseph@intel.com> Signed-off-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: fenghua.yu@intel.com Cc: tony.luck@intel.com Cc: gavin.hindman@intel.com Cc: hpa@zytor.com Link: https://lkml.kernel.org/r/231f742dbb7b00a31cc104416860e27dba6b072d.1539384145.git.reinette.chatre@intel.com
484 lines
12 KiB
C
484 lines
12 KiB
C
/*
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* Resource Director Technology(RDT)
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* - Cache Allocation code.
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*
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* Copyright (C) 2016 Intel Corporation
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*
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* Authors:
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* Fenghua Yu <fenghua.yu@intel.com>
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* Tony Luck <tony.luck@intel.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms and conditions of the GNU General Public License,
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* version 2, as published by the Free Software Foundation.
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*
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* This program is distributed in the hope it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* More information about RDT be found in the Intel (R) x86 Architecture
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* Software Developer Manual June 2016, volume 3, section 17.17.
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernfs.h>
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#include <linux/seq_file.h>
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#include <linux/slab.h>
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#include "intel_rdt.h"
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/*
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* Check whether MBA bandwidth percentage value is correct. The value is
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* checked against the minimum and max bandwidth values specified by the
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* hardware. The allocated bandwidth percentage is rounded to the next
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* control step available on the hardware.
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*/
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static bool bw_validate(char *buf, unsigned long *data, struct rdt_resource *r)
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{
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unsigned long bw;
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int ret;
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/*
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* Only linear delay values is supported for current Intel SKUs.
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*/
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if (!r->membw.delay_linear) {
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rdt_last_cmd_puts("No support for non-linear MB domains\n");
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return false;
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}
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ret = kstrtoul(buf, 10, &bw);
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if (ret) {
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rdt_last_cmd_printf("Non-decimal digit in MB value %s\n", buf);
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return false;
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}
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if ((bw < r->membw.min_bw || bw > r->default_ctrl) &&
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!is_mba_sc(r)) {
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rdt_last_cmd_printf("MB value %ld out of range [%d,%d]\n", bw,
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r->membw.min_bw, r->default_ctrl);
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return false;
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}
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*data = roundup(bw, (unsigned long)r->membw.bw_gran);
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return true;
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}
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int parse_bw(struct rdt_parse_data *data, struct rdt_resource *r,
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struct rdt_domain *d)
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{
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unsigned long bw_val;
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if (d->have_new_ctrl) {
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rdt_last_cmd_printf("duplicate domain %d\n", d->id);
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return -EINVAL;
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}
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if (!bw_validate(data->buf, &bw_val, r))
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return -EINVAL;
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d->new_ctrl = bw_val;
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d->have_new_ctrl = true;
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return 0;
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}
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/*
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* Check whether a cache bit mask is valid. The SDM says:
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* Please note that all (and only) contiguous '1' combinations
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* are allowed (e.g. FFFFH, 0FF0H, 003CH, etc.).
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* Additionally Haswell requires at least two bits set.
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*/
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static bool cbm_validate(char *buf, u32 *data, struct rdt_resource *r)
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{
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unsigned long first_bit, zero_bit, val;
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unsigned int cbm_len = r->cache.cbm_len;
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int ret;
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ret = kstrtoul(buf, 16, &val);
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if (ret) {
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rdt_last_cmd_printf("non-hex character in mask %s\n", buf);
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return false;
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}
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if (val == 0 || val > r->default_ctrl) {
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rdt_last_cmd_puts("mask out of range\n");
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return false;
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}
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first_bit = find_first_bit(&val, cbm_len);
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zero_bit = find_next_zero_bit(&val, cbm_len, first_bit);
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if (find_next_bit(&val, cbm_len, zero_bit) < cbm_len) {
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rdt_last_cmd_printf("mask %lx has non-consecutive 1-bits\n", val);
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return false;
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}
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if ((zero_bit - first_bit) < r->cache.min_cbm_bits) {
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rdt_last_cmd_printf("Need at least %d bits in mask\n",
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r->cache.min_cbm_bits);
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return false;
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}
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*data = val;
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return true;
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}
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/*
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* Read one cache bit mask (hex). Check that it is valid for the current
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* resource type.
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*/
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int parse_cbm(struct rdt_parse_data *data, struct rdt_resource *r,
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struct rdt_domain *d)
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{
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struct rdtgroup *rdtgrp = data->rdtgrp;
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u32 cbm_val;
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if (d->have_new_ctrl) {
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rdt_last_cmd_printf("duplicate domain %d\n", d->id);
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return -EINVAL;
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}
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/*
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* Cannot set up more than one pseudo-locked region in a cache
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* hierarchy.
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*/
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if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
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rdtgroup_pseudo_locked_in_hierarchy(d)) {
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rdt_last_cmd_printf("pseudo-locked region in hierarchy\n");
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return -EINVAL;
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}
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if (!cbm_validate(data->buf, &cbm_val, r))
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return -EINVAL;
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if ((rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
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rdtgrp->mode == RDT_MODE_SHAREABLE) &&
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rdtgroup_cbm_overlaps_pseudo_locked(d, cbm_val)) {
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rdt_last_cmd_printf("CBM overlaps with pseudo-locked region\n");
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return -EINVAL;
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}
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/*
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* The CBM may not overlap with the CBM of another closid if
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* either is exclusive.
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*/
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if (rdtgroup_cbm_overlaps(r, d, cbm_val, rdtgrp->closid, true)) {
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rdt_last_cmd_printf("overlaps with exclusive group\n");
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return -EINVAL;
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}
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if (rdtgroup_cbm_overlaps(r, d, cbm_val, rdtgrp->closid, false)) {
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if (rdtgrp->mode == RDT_MODE_EXCLUSIVE ||
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rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
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rdt_last_cmd_printf("overlaps with other group\n");
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return -EINVAL;
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}
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}
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d->new_ctrl = cbm_val;
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d->have_new_ctrl = true;
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return 0;
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}
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/*
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* For each domain in this resource we expect to find a series of:
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* id=mask
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* separated by ";". The "id" is in decimal, and must match one of
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* the "id"s for this resource.
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*/
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static int parse_line(char *line, struct rdt_resource *r,
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struct rdtgroup *rdtgrp)
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{
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struct rdt_parse_data data;
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char *dom = NULL, *id;
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struct rdt_domain *d;
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unsigned long dom_id;
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if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP &&
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r->rid == RDT_RESOURCE_MBA) {
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rdt_last_cmd_puts("Cannot pseudo-lock MBA resource\n");
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return -EINVAL;
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}
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next:
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if (!line || line[0] == '\0')
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return 0;
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dom = strsep(&line, ";");
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id = strsep(&dom, "=");
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if (!dom || kstrtoul(id, 10, &dom_id)) {
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rdt_last_cmd_puts("Missing '=' or non-numeric domain\n");
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return -EINVAL;
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}
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dom = strim(dom);
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list_for_each_entry(d, &r->domains, list) {
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if (d->id == dom_id) {
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data.buf = dom;
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data.rdtgrp = rdtgrp;
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if (r->parse_ctrlval(&data, r, d))
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return -EINVAL;
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if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
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/*
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* In pseudo-locking setup mode and just
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* parsed a valid CBM that should be
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* pseudo-locked. Only one locked region per
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* resource group and domain so just do
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* the required initialization for single
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* region and return.
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*/
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rdtgrp->plr->r = r;
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rdtgrp->plr->d = d;
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rdtgrp->plr->cbm = d->new_ctrl;
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d->plr = rdtgrp->plr;
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return 0;
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}
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goto next;
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}
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}
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return -EINVAL;
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}
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int update_domains(struct rdt_resource *r, int closid)
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{
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struct msr_param msr_param;
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cpumask_var_t cpu_mask;
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struct rdt_domain *d;
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bool mba_sc;
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u32 *dc;
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int cpu;
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if (!zalloc_cpumask_var(&cpu_mask, GFP_KERNEL))
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return -ENOMEM;
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msr_param.low = closid;
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msr_param.high = msr_param.low + 1;
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msr_param.res = r;
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mba_sc = is_mba_sc(r);
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list_for_each_entry(d, &r->domains, list) {
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dc = !mba_sc ? d->ctrl_val : d->mbps_val;
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if (d->have_new_ctrl && d->new_ctrl != dc[closid]) {
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cpumask_set_cpu(cpumask_any(&d->cpu_mask), cpu_mask);
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dc[closid] = d->new_ctrl;
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}
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}
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/*
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* Avoid writing the control msr with control values when
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* MBA software controller is enabled
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*/
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if (cpumask_empty(cpu_mask) || mba_sc)
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goto done;
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cpu = get_cpu();
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/* Update CBM on this cpu if it's in cpu_mask. */
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if (cpumask_test_cpu(cpu, cpu_mask))
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rdt_ctrl_update(&msr_param);
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/* Update CBM on other cpus. */
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smp_call_function_many(cpu_mask, rdt_ctrl_update, &msr_param, 1);
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put_cpu();
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done:
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free_cpumask_var(cpu_mask);
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return 0;
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}
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static int rdtgroup_parse_resource(char *resname, char *tok,
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struct rdtgroup *rdtgrp)
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{
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struct rdt_resource *r;
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for_each_alloc_enabled_rdt_resource(r) {
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if (!strcmp(resname, r->name) && rdtgrp->closid < r->num_closid)
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return parse_line(tok, r, rdtgrp);
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}
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rdt_last_cmd_printf("unknown/unsupported resource name '%s'\n", resname);
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return -EINVAL;
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}
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ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
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char *buf, size_t nbytes, loff_t off)
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{
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struct rdtgroup *rdtgrp;
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struct rdt_domain *dom;
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struct rdt_resource *r;
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char *tok, *resname;
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int ret = 0;
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/* Valid input requires a trailing newline */
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if (nbytes == 0 || buf[nbytes - 1] != '\n')
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return -EINVAL;
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buf[nbytes - 1] = '\0';
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rdtgrp = rdtgroup_kn_lock_live(of->kn);
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if (!rdtgrp) {
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rdtgroup_kn_unlock(of->kn);
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return -ENOENT;
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}
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rdt_last_cmd_clear();
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/*
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* No changes to pseudo-locked region allowed. It has to be removed
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* and re-created instead.
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*/
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if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
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ret = -EINVAL;
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rdt_last_cmd_puts("resource group is pseudo-locked\n");
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goto out;
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}
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for_each_alloc_enabled_rdt_resource(r) {
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list_for_each_entry(dom, &r->domains, list)
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dom->have_new_ctrl = false;
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}
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while ((tok = strsep(&buf, "\n")) != NULL) {
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resname = strim(strsep(&tok, ":"));
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if (!tok) {
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rdt_last_cmd_puts("Missing ':'\n");
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ret = -EINVAL;
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goto out;
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}
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if (tok[0] == '\0') {
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rdt_last_cmd_printf("Missing '%s' value\n", resname);
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ret = -EINVAL;
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goto out;
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}
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ret = rdtgroup_parse_resource(resname, tok, rdtgrp);
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if (ret)
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goto out;
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}
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for_each_alloc_enabled_rdt_resource(r) {
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ret = update_domains(r, rdtgrp->closid);
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if (ret)
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goto out;
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}
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if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
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/*
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* If pseudo-locking fails we keep the resource group in
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* mode RDT_MODE_PSEUDO_LOCKSETUP with its class of service
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* active and updated for just the domain the pseudo-locked
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* region was requested for.
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*/
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ret = rdtgroup_pseudo_lock_create(rdtgrp);
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}
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out:
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rdtgroup_kn_unlock(of->kn);
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return ret ?: nbytes;
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}
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static void show_doms(struct seq_file *s, struct rdt_resource *r, int closid)
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{
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struct rdt_domain *dom;
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bool sep = false;
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u32 ctrl_val;
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seq_printf(s, "%*s:", max_name_width, r->name);
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list_for_each_entry(dom, &r->domains, list) {
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if (sep)
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seq_puts(s, ";");
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ctrl_val = (!is_mba_sc(r) ? dom->ctrl_val[closid] :
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dom->mbps_val[closid]);
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seq_printf(s, r->format_str, dom->id, max_data_width,
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ctrl_val);
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sep = true;
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}
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seq_puts(s, "\n");
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}
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int rdtgroup_schemata_show(struct kernfs_open_file *of,
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struct seq_file *s, void *v)
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{
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struct rdtgroup *rdtgrp;
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struct rdt_resource *r;
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int ret = 0;
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u32 closid;
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rdtgrp = rdtgroup_kn_lock_live(of->kn);
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if (rdtgrp) {
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if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) {
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for_each_alloc_enabled_rdt_resource(r)
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seq_printf(s, "%s:uninitialized\n", r->name);
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} else if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKED) {
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if (!rdtgrp->plr->d) {
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rdt_last_cmd_clear();
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rdt_last_cmd_puts("Cache domain offline\n");
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ret = -ENODEV;
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} else {
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seq_printf(s, "%s:%d=%x\n",
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rdtgrp->plr->r->name,
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rdtgrp->plr->d->id,
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rdtgrp->plr->cbm);
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}
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} else {
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closid = rdtgrp->closid;
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for_each_alloc_enabled_rdt_resource(r) {
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if (closid < r->num_closid)
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show_doms(s, r, closid);
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}
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}
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} else {
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ret = -ENOENT;
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}
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rdtgroup_kn_unlock(of->kn);
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return ret;
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}
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void mon_event_read(struct rmid_read *rr, struct rdt_domain *d,
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struct rdtgroup *rdtgrp, int evtid, int first)
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{
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/*
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* setup the parameters to send to the IPI to read the data.
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*/
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rr->rgrp = rdtgrp;
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rr->evtid = evtid;
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rr->d = d;
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rr->val = 0;
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rr->first = first;
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smp_call_function_any(&d->cpu_mask, mon_event_count, rr, 1);
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}
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int rdtgroup_mondata_show(struct seq_file *m, void *arg)
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{
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struct kernfs_open_file *of = m->private;
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u32 resid, evtid, domid;
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struct rdtgroup *rdtgrp;
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struct rdt_resource *r;
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union mon_data_bits md;
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struct rdt_domain *d;
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struct rmid_read rr;
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int ret = 0;
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rdtgrp = rdtgroup_kn_lock_live(of->kn);
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md.priv = of->kn->priv;
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resid = md.u.rid;
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domid = md.u.domid;
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evtid = md.u.evtid;
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r = &rdt_resources_all[resid];
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d = rdt_find_domain(r, domid, NULL);
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if (!d) {
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ret = -ENOENT;
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goto out;
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}
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mon_event_read(&rr, d, rdtgrp, evtid, false);
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if (rr.val & RMID_VAL_ERROR)
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seq_puts(m, "Error\n");
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else if (rr.val & RMID_VAL_UNAVAIL)
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seq_puts(m, "Unavailable\n");
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else
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seq_printf(m, "%llu\n", rr.val * r->mon_scale);
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out:
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rdtgroup_kn_unlock(of->kn);
|
|
return ret;
|
|
}
|