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author | Li Rongqing <lirongqing@baidu.com> | 2019-05-15 01:46:20 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-15 12:54:00 +0300 |
commit | 20de754a7d8852eb25a952b5181a278600a1698b (patch) | |
tree | 313f2c793aa7b50ec92b4e0aecca330eebc9431b | |
parent | 91ae202e2c88a026eb2065fbee10b8e80591a27d (diff) | |
download | linux-20de754a7d8852eb25a952b5181a278600a1698b.tar.xz |
ipc: prevent lockup on alloc_msg and free_msg
[ Upstream commit d6a2946a88f524a47cc9b79279667137899db807 ]
msgctl10 of ltp triggers the following lockup When CONFIG_KASAN is
enabled on large memory SMP systems, the pages initialization can take a
long time, if msgctl10 requests a huge block memory, and it will block
rcu scheduler, so release cpu actively.
After adding schedule() in free_msg, free_msg can not be called when
holding spinlock, so adding msg to a tmp list, and free it out of
spinlock
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-1 rcu_node (CPUs 16-31): P32505
rcu: Tasks blocked on level-1 rcu_node (CPUs 48-63): P34978
rcu: (detected by 11, t=35024 jiffies, g=44237529, q=16542267)
msgctl10 R running task 21608 32505 2794 0x00000082
Call Trace:
preempt_schedule_irq+0x4c/0xb0
retint_kernel+0x1b/0x2d
RIP: 0010:__is_insn_slot_addr+0xfb/0x250
Code: 82 1d 00 48 8b 9b 90 00 00 00 4c 89 f7 49 c1 ee 03 e8 59 83 1d 00 48 b8 00 00 00 00 00 fc ff df 4c 39 eb 48 89 9d 58 ff ff ff <41> c6 04 06 f8 74 66 4c 8d 75 98 4c 89 f1 48 c1 e9 03 48 01 c8 48
RSP: 0018:ffff88bce041f758 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffffffff8471bc50 RCX: ffffffff828a2a57
RDX: dffffc0000000000 RSI: dffffc0000000000 RDI: ffff88bce041f780
RBP: ffff88bce041f828 R08: ffffed15f3f4c5b3 R09: ffffed15f3f4c5b3
R10: 0000000000000001 R11: ffffed15f3f4c5b2 R12: 000000318aee9b73
R13: ffffffff8471bc50 R14: 1ffff1179c083ef0 R15: 1ffff1179c083eec
kernel_text_address+0xc1/0x100
__kernel_text_address+0xe/0x30
unwind_get_return_address+0x2f/0x50
__save_stack_trace+0x92/0x100
create_object+0x380/0x650
__kmalloc+0x14c/0x2b0
load_msg+0x38/0x1a0
do_msgsnd+0x19e/0xcf0
do_syscall_64+0x117/0x400
entry_SYSCALL_64_after_hwframe+0x49/0xbe
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-1 rcu_node (CPUs 0-15): P32170
rcu: (detected by 14, t=35016 jiffies, g=44237525, q=12423063)
msgctl10 R running task 21608 32170 32155 0x00000082
Call Trace:
preempt_schedule_irq+0x4c/0xb0
retint_kernel+0x1b/0x2d
RIP: 0010:lock_acquire+0x4d/0x340
Code: 48 81 ec c0 00 00 00 45 89 c6 4d 89 cf 48 8d 6c 24 20 48 89 3c 24 48 8d bb e4 0c 00 00 89 74 24 0c 48 c7 44 24 20 b3 8a b5 41 <48> c1 ed 03 48 c7 44 24 28 b4 25 18 84 48 c7 44 24 30 d0 54 7a 82
RSP: 0018:ffff88af83417738 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: ffff88bd335f3080 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88bd335f3d64
RBP: ffff88af83417758 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: ffffed13f3f745b2 R12: 0000000000000000
R13: 0000000000000002 R14: 0000000000000000 R15: 0000000000000000
is_bpf_text_address+0x32/0xe0
kernel_text_address+0xec/0x100
__kernel_text_address+0xe/0x30
unwind_get_return_address+0x2f/0x50
__save_stack_trace+0x92/0x100
save_stack+0x32/0xb0
__kasan_slab_free+0x130/0x180
kfree+0xfa/0x2d0
free_msg+0x24/0x50
do_msgrcv+0x508/0xe60
do_syscall_64+0x117/0x400
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Davidlohr said:
"So after releasing the lock, the msg rbtree/list is empty and new
calls will not see those in the newly populated tmp_msg list, and
therefore they cannot access the delayed msg freeing pointers, which
is good. Also the fact that the node_cache is now freed before the
actual messages seems to be harmless as this is wanted for
msg_insert() avoiding GFP_ATOMIC allocations, and after releasing the
info->lock the thing is freed anyway so it should not change things"
Link: http://lkml.kernel.org/r/1552029161-4957-1-git-send-email-lirongqing@baidu.com
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: Zhang Yu <zhangyu31@baidu.com>
Reviewed-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
-rw-r--r-- | ipc/mqueue.c | 10 | ||||
-rw-r--r-- | ipc/msgutil.c | 6 |
2 files changed, 14 insertions, 2 deletions
diff --git a/ipc/mqueue.c b/ipc/mqueue.c index c0d58f390c3b..bce7af1546d9 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -391,7 +391,8 @@ static void mqueue_evict_inode(struct inode *inode) struct user_struct *user; unsigned long mq_bytes, mq_treesize; struct ipc_namespace *ipc_ns; - struct msg_msg *msg; + struct msg_msg *msg, *nmsg; + LIST_HEAD(tmp_msg); clear_inode(inode); @@ -402,10 +403,15 @@ static void mqueue_evict_inode(struct inode *inode) info = MQUEUE_I(inode); spin_lock(&info->lock); while ((msg = msg_get(info)) != NULL) - free_msg(msg); + list_add_tail(&msg->m_list, &tmp_msg); kfree(info->node_cache); spin_unlock(&info->lock); + list_for_each_entry_safe(msg, nmsg, &tmp_msg, m_list) { + list_del(&msg->m_list); + free_msg(msg); + } + /* Total amount of bytes accounted for the mqueue */ mq_treesize = info->attr.mq_maxmsg * sizeof(struct msg_msg) + min_t(unsigned int, info->attr.mq_maxmsg, MQ_PRIO_MAX) * diff --git a/ipc/msgutil.c b/ipc/msgutil.c index 84598025a6ad..e65593742e2b 100644 --- a/ipc/msgutil.c +++ b/ipc/msgutil.c @@ -18,6 +18,7 @@ #include <linux/utsname.h> #include <linux/proc_ns.h> #include <linux/uaccess.h> +#include <linux/sched.h> #include "util.h" @@ -64,6 +65,9 @@ static struct msg_msg *alloc_msg(size_t len) pseg = &msg->next; while (len > 0) { struct msg_msgseg *seg; + + cond_resched(); + alen = min(len, DATALEN_SEG); seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL_ACCOUNT); if (seg == NULL) @@ -176,6 +180,8 @@ void free_msg(struct msg_msg *msg) kfree(msg); while (seg != NULL) { struct msg_msgseg *tmp = seg->next; + + cond_resched(); kfree(seg); seg = tmp; } |