Revision 89c38422e072bb453e3045b8f1b962a344c3edea authored by John Garry on 08 November 2018, 10:17:03 UTC, committed by Rob Herring on 08 November 2018, 18:44:34 UTC
Currently the NUMA distance map parsing does not validate the distance table for the distance-matrix rules 1-2 in [1]. However the arch NUMA code may enforce some of these rules, but not all. Such is the case for the arm64 port, which does not enforce the rule that the distance between separates nodes cannot equal LOCAL_DISTANCE. The patch adds the following rules validation: - distance of node to self equals LOCAL_DISTANCE - distance of separate nodes > LOCAL_DISTANCE This change avoids a yet-unresolved crash reported in [2]. A note on dealing with symmetrical distances between nodes: Validating symmetrical distances between nodes is difficult. If it were mandated in the bindings that every distance must be recorded in the table, then it would be easy. However, it isn't. In addition to this, it is also possible to record [b, a] distance only (and not [a, b]). So, when processing the table for [b, a], we cannot assert that current distance of [a, b] != [b, a] as invalid, as [a, b] distance may not be present in the table and current distance would be default at REMOTE_DISTANCE. As such, we maintain the policy that we overwrite distance [a, b] = [b, a] for b > a. This policy is different to kernel ACPI SLIT validation, which allows non-symmetrical distances (ACPI spec SLIT rules allow it). However, the distance debug message is dropped as it may be misleading (for a distance which is later overwritten). Some final notes on semantics: - It is implied that it is the responsibility of the arch NUMA code to reset the NUMA distance map for an error in distance map parsing. - It is the responsibility of the FW NUMA topology parsing (whether OF or ACPI) to enforce NUMA distance rules, and not arch NUMA code. [1] Documents/devicetree/bindings/numa.txt [2] https://www.spinics.net/lists/arm-kernel/msg683304.html Cc: stable@vger.kernel.org # 4.7 Signed-off-by: John Garry <john.garry@huawei.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Rob Herring <robh@kernel.org>
1 parent 6778be4
compat.c
// SPDX-License-Identifier: GPL-2.0
/*
* 32 bit compatibility code for System V IPC
*
* Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
* Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
* Copyright (C) 1999 Arun Sharma <arun.sharma@intel.com>
* Copyright (C) 2000 VA Linux Co
* Copyright (C) 2000 Don Dugger <n0ano@valinux.com>
* Copyright (C) 2000 Hewlett-Packard Co.
* Copyright (C) 2000 David Mosberger-Tang <davidm@hpl.hp.com>
* Copyright (C) 2000 Gerhard Tonn (ton@de.ibm.com)
* Copyright (C) 2000-2002 Andi Kleen, SuSE Labs (x86-64 port)
* Copyright (C) 2000 Silicon Graphics, Inc.
* Copyright (C) 2001 IBM
* Copyright (C) 2004 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Copyright (C) 2004 Arnd Bergmann (arnd@arndb.de)
*
* This code is collected from the versions for sparc64, mips64, s390x, ia64,
* ppc64 and x86_64, all of which are based on the original sparc64 version
* by Jakub Jelinek.
*
*/
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/highuid.h>
#include <linux/init.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/syscalls.h>
#include <linux/ptrace.h>
#include <linux/mutex.h>
#include <linux/uaccess.h>
#include "util.h"
int get_compat_ipc64_perm(struct ipc64_perm *to,
struct compat_ipc64_perm __user *from)
{
struct compat_ipc64_perm v;
if (copy_from_user(&v, from, sizeof(v)))
return -EFAULT;
to->uid = v.uid;
to->gid = v.gid;
to->mode = v.mode;
return 0;
}
int get_compat_ipc_perm(struct ipc64_perm *to,
struct compat_ipc_perm __user *from)
{
struct compat_ipc_perm v;
if (copy_from_user(&v, from, sizeof(v)))
return -EFAULT;
to->uid = v.uid;
to->gid = v.gid;
to->mode = v.mode;
return 0;
}
void to_compat_ipc64_perm(struct compat_ipc64_perm *to, struct ipc64_perm *from)
{
to->key = from->key;
to->uid = from->uid;
to->gid = from->gid;
to->cuid = from->cuid;
to->cgid = from->cgid;
to->mode = from->mode;
to->seq = from->seq;
}
void to_compat_ipc_perm(struct compat_ipc_perm *to, struct ipc64_perm *from)
{
to->key = from->key;
SET_UID(to->uid, from->uid);
SET_GID(to->gid, from->gid);
SET_UID(to->cuid, from->cuid);
SET_GID(to->cgid, from->cgid);
to->mode = from->mode;
to->seq = from->seq;
}
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