From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, cai@lca.pw, jgg@mellanox.com,
linux-mm@kvack.org, mm-commits@vger.kernel.org,
paulmck@kernel.org, torvalds@linux-foundation.org
Subject: [patch 08/10] mm/mmu_notifier: silence PROVE_RCU_LIST warnings
Date: Sat, 21 Mar 2020 18:22:34 -0700 [thread overview]
Message-ID: <20200322012234.XRpe6rsK4%akpm@linux-foundation.org> (raw)
In-Reply-To: <20200321181954.c0564dfd5514cd742b534884@linux-foundation.org>
From: Qian Cai <cai@lca.pw>
Subject: mm/mmu_notifier: silence PROVE_RCU_LIST warnings
It is safe to traverse mm->notifier_subscriptions->list either under SRCU
read lock or mm->notifier_subscriptions->lock using
hlist_for_each_entry_rcu(). Silence the PROVE_RCU_LIST false positives,
for example,
WARNING: suspicious RCU usage
-----------------------------
mm/mmu_notifier.c:484 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
3 locks held by libvirtd/802:
#0: ffff9321e3f58148 (&mm->mmap_sem#2){++++}, at: do_mprotect_pkey+0xe1/0x3e0
#1: ffffffff91ae6160 (mmu_notifier_invalidate_range_start){+.+.}, at: change_p4d_range+0x5fa/0x800
#2: ffffffff91ae6e08 (srcu){....}, at: __mmu_notifier_invalidate_range_start+0x178/0x460
stack backtrace:
CPU: 7 PID: 802 Comm: libvirtd Tainted: G I 5.6.0-rc6-next-20200317+ #2
Hardware name: HP ProLiant BL460c Gen8, BIOS I31 11/02/2014
Call Trace:
dump_stack+0xa4/0xfe
lockdep_rcu_suspicious+0xeb/0xf5
__mmu_notifier_invalidate_range_start+0x3ff/0x460
change_p4d_range+0x746/0x800
change_protection+0x1df/0x300
mprotect_fixup+0x245/0x3e0
do_mprotect_pkey+0x23b/0x3e0
__x64_sys_mprotect+0x51/0x70
do_syscall_64+0x91/0xae8
entry_SYSCALL_64_after_hwframe+0x49/0xb3
Link: http://lkml.kernel.org/r/20200317175640.2047-1-cai@lca.pw
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/mmu_notifier.c | 27 ++++++++++++++++++---------
1 file changed, 18 insertions(+), 9 deletions(-)
--- a/mm/mmu_notifier.c~mm-mmu_notifier-silence-prove_rcu_list-warnings
+++ a/mm/mmu_notifier.c
@@ -307,7 +307,8 @@ static void mn_hlist_release(struct mmu_
* ->release returns.
*/
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist)
+ hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist,
+ srcu_read_lock_held(&srcu))
/*
* If ->release runs before mmu_notifier_unregister it must be
* handled, as it's the only way for the driver to flush all
@@ -370,7 +371,8 @@ int __mmu_notifier_clear_flush_young(str
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(subscription,
- &mm->notifier_subscriptions->list, hlist) {
+ &mm->notifier_subscriptions->list, hlist,
+ srcu_read_lock_held(&srcu)) {
if (subscription->ops->clear_flush_young)
young |= subscription->ops->clear_flush_young(
subscription, mm, start, end);
@@ -389,7 +391,8 @@ int __mmu_notifier_clear_young(struct mm
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(subscription,
- &mm->notifier_subscriptions->list, hlist) {
+ &mm->notifier_subscriptions->list, hlist,
+ srcu_read_lock_held(&srcu)) {
if (subscription->ops->clear_young)
young |= subscription->ops->clear_young(subscription,
mm, start, end);
@@ -407,7 +410,8 @@ int __mmu_notifier_test_young(struct mm_
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(subscription,
- &mm->notifier_subscriptions->list, hlist) {
+ &mm->notifier_subscriptions->list, hlist,
+ srcu_read_lock_held(&srcu)) {
if (subscription->ops->test_young) {
young = subscription->ops->test_young(subscription, mm,
address);
@@ -428,7 +432,8 @@ void __mmu_notifier_change_pte(struct mm
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(subscription,
- &mm->notifier_subscriptions->list, hlist) {
+ &mm->notifier_subscriptions->list, hlist,
+ srcu_read_lock_held(&srcu)) {
if (subscription->ops->change_pte)
subscription->ops->change_pte(subscription, mm, address,
pte);
@@ -476,7 +481,8 @@ static int mn_hlist_invalidate_range_sta
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist) {
+ hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist,
+ srcu_read_lock_held(&srcu)) {
const struct mmu_notifier_ops *ops = subscription->ops;
if (ops->invalidate_range_start) {
@@ -528,7 +534,8 @@ mn_hlist_invalidate_end(struct mmu_notif
int id;
id = srcu_read_lock(&srcu);
- hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist) {
+ hlist_for_each_entry_rcu(subscription, &subscriptions->list, hlist,
+ srcu_read_lock_held(&srcu)) {
/*
* Call invalidate_range here too to avoid the need for the
* subsystem of having to register an invalidate_range_end
@@ -582,7 +589,8 @@ void __mmu_notifier_invalidate_range(str
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(subscription,
- &mm->notifier_subscriptions->list, hlist) {
+ &mm->notifier_subscriptions->list, hlist,
+ srcu_read_lock_held(&srcu)) {
if (subscription->ops->invalidate_range)
subscription->ops->invalidate_range(subscription, mm,
start, end);
@@ -714,7 +722,8 @@ find_get_mmu_notifier(struct mm_struct *
spin_lock(&mm->notifier_subscriptions->lock);
hlist_for_each_entry_rcu(subscription,
- &mm->notifier_subscriptions->list, hlist) {
+ &mm->notifier_subscriptions->list, hlist,
+ lockdep_is_held(&mm->notifier_subscriptions->lock)) {
if (subscription->ops != ops)
continue;
_
next prev parent reply other threads:[~2020-03-22 1:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-22 1:19 incoming Andrew Morton
2020-03-22 1:22 ` [patch 01/10] memcg: fix NULL pointer dereference in __mem_cgroup_usage_unregister_event Andrew Morton
2020-03-22 1:22 ` [patch 02/10] mm/hotplug: fix hot remove failure in SPARSEMEM|!VMEMMAP case Andrew Morton
2020-03-22 1:22 ` [patch 03/10] page-flags: fix a crash at SetPageError(THP_SWAP) Andrew Morton
2020-03-22 1:22 ` [patch 04/10] mm, memcg: fix corruption on 64-bit divisor in memory.high throttling Andrew Morton
2020-03-22 1:22 ` [patch 05/10] mm, memcg: throttle allocators based on ancestral memory.high Andrew Morton
2020-03-22 1:22 ` [patch 06/10] mm: do not allow MADV_PAGEOUT for CoW pages Andrew Morton
2020-03-22 1:22 ` [patch 07/10] epoll: fix possible lost wakeup on epoll_ctl() path Andrew Morton
2020-03-22 1:22 ` Andrew Morton [this message]
2020-03-22 1:22 ` [patch 09/10] mm, slub: prevent kmalloc_node crashes and memory leaks Andrew Morton
2020-03-22 1:22 ` [patch 10/10] x86/mm: split vmalloc_sync_all() Andrew Morton
2020-03-22 1:39 ` + tools-testing-selftests-vm-mlock2-tests-fix-mlock2-false-negative-errors.patch added to -mm tree Andrew Morton
2020-03-22 4:39 ` + libfs-fix-infoleak-in-simple_attr_read.patch " Andrew Morton
2020-03-22 4:41 ` + bus-mhi-fix-printk-format-for-size_t.patch " Andrew Morton
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200322012234.XRpe6rsK4%akpm@linux-foundation.org \
--to=akpm@linux-foundation.org \
--cc=cai@lca.pw \
--cc=jgg@mellanox.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mm-commits@vger.kernel.org \
--cc=paulmck@kernel.org \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).