forked from Minki/linux
87773dd56d
In debugging an application that receives -ENOMEM from ib_reg_mr(), I
found that ib_umem_get() can fail because the pinned_vm count has
wrapped causing it to always be larger than the lock limit even with
RLIMIT_MEMLOCK set to RLIM_INFINITY.
The wrapping of pinned_vm occurs because the process that calls
ib_reg_mr() will have its mm->pinned_vm count incremented. Later a
different process with a different mm_struct than the one that
allocated the ib_umem struct ends up releasing it which results in
decrementing the new processes mm->pinned_vm count past zero and
wrapping.
I'm not entirely sure what circumstances cause a different process to
release the ib_umem than the one that allocated it but the kernel
stack trace of the freeing process from my situation looks like the
following:
Call Trace:
[<ffffffff814d64b1>] dump_stack+0x19/0x1b
[<ffffffffa0b522a5>] ib_umem_release+0x1f5/0x200 [ib_core]
[<ffffffffa0b90681>] mlx4_ib_destroy_qp+0x241/0x440 [mlx4_ib]
[<ffffffffa0b4d93c>] ib_destroy_qp+0x12c/0x170 [ib_core]
[<ffffffffa0cc7129>] ib_uverbs_close+0x259/0x4e0 [ib_uverbs]
[<ffffffff81141cba>] __fput+0xba/0x240
[<ffffffff81141e4e>] ____fput+0xe/0x10
[<ffffffff81060894>] task_work_run+0xc4/0xe0
[<ffffffff810029e5>] do_notify_resume+0x95/0xa0
[<ffffffff814e3dd0>] int_signal+0x12/0x17
The following patch fixes the issue by storing the pid struct of the
process that calls ib_umem_get() so that ib_umem_release and/or
ib_umem_account() can properly decrement the pinned_vm count of the
correct mm_struct.
Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Reviewed-by: Shachar Raindel <raindel@mellanox.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
80 lines
2.5 KiB
C
80 lines
2.5 KiB
C
/*
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* Copyright (c) 2007 Cisco Systems. All rights reserved.
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*
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* This software is available to you under a choice of one of two
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* licenses. You may choose to be licensed under the terms of the GNU
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* General Public License (GPL) Version 2, available from the file
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* COPYING in the main directory of this source tree, or the
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* OpenIB.org BSD license below:
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*
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* Redistribution and use in source and binary forms, with or
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* without modification, are permitted provided that the following
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* conditions are met:
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*
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* - Redistributions of source code must retain the above
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* copyright notice, this list of conditions and the following
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* disclaimer.
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*
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* - Redistributions in binary form must reproduce the above
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* copyright notice, this list of conditions and the following
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* disclaimer in the documentation and/or other materials
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* provided with the distribution.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
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* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
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* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
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* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
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* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#ifndef IB_UMEM_H
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#define IB_UMEM_H
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#include <linux/list.h>
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#include <linux/scatterlist.h>
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#include <linux/workqueue.h>
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struct ib_ucontext;
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struct ib_umem {
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struct ib_ucontext *context;
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size_t length;
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int offset;
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int page_size;
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int writable;
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int hugetlb;
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struct work_struct work;
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struct pid *pid;
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struct mm_struct *mm;
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unsigned long diff;
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struct sg_table sg_head;
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int nmap;
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int npages;
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};
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#ifdef CONFIG_INFINIBAND_USER_MEM
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struct ib_umem *ib_umem_get(struct ib_ucontext *context, unsigned long addr,
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size_t size, int access, int dmasync);
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void ib_umem_release(struct ib_umem *umem);
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int ib_umem_page_count(struct ib_umem *umem);
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#else /* CONFIG_INFINIBAND_USER_MEM */
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#include <linux/err.h>
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static inline struct ib_umem *ib_umem_get(struct ib_ucontext *context,
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unsigned long addr, size_t size,
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int access, int dmasync) {
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return ERR_PTR(-EINVAL);
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}
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static inline void ib_umem_release(struct ib_umem *umem) { }
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static inline int ib_umem_page_count(struct ib_umem *umem) { return 0; }
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#endif /* CONFIG_INFINIBAND_USER_MEM */
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#endif /* IB_UMEM_H */
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