f3713fd9cf
Commit 93e6f119c0 ("ipc/mqueue: cleanup definition names and
locations") added global hardcoded limits to the amount of message
queues that can be created. While these limits are per-namespace,
reality is that it ends up breaking userspace applications.
Historically users have, at least in theory, been able to create up to
INT_MAX queues, and limiting it to just 1024 is way too low and dramatic
for some workloads and use cases. For instance, Madars reports:
"This update imposes bad limits on our multi-process application. As
our app uses approaches that each process opens its own set of queues
(usually something about 3-5 queues per process). In some scenarios
we might run up to 3000 processes or more (which of-course for linux
is not a problem). Thus we might need up to 9000 queues or more. All
processes run under one user."
Other affected users can be found in launchpad bug #1155695:
https://bugs.launchpad.net/ubuntu/+source/manpages/+bug/1155695
Instead of increasing this limit, revert it entirely and fallback to the
original way of dealing queue limits -- where once a user's resource
limit is reached, and all memory is used, new queues cannot be created.
Signed-off-by: Davidlohr Bueso <davidlohr@hp.com>
Reported-by: Madars Vitolins <m@silodev.com>
Acked-by: Doug Ledford <dledford@redhat.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: <stable@vger.kernel.org> [3.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
125 lines
2.9 KiB
C
125 lines
2.9 KiB
C
/*
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* Copyright (C) 2007 IBM Corporation
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*
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* Author: Cedric Le Goater <clg@fr.ibm.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*/
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#include <linux/nsproxy.h>
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#include <linux/ipc_namespace.h>
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#include <linux/sysctl.h>
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#ifdef CONFIG_PROC_SYSCTL
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static void *get_mq(ctl_table *table)
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{
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char *which = table->data;
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struct ipc_namespace *ipc_ns = current->nsproxy->ipc_ns;
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which = (which - (char *)&init_ipc_ns) + (char *)ipc_ns;
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return which;
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}
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static int proc_mq_dointvec(ctl_table *table, int write,
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void __user *buffer, size_t *lenp, loff_t *ppos)
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{
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struct ctl_table mq_table;
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memcpy(&mq_table, table, sizeof(mq_table));
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mq_table.data = get_mq(table);
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return proc_dointvec(&mq_table, write, buffer, lenp, ppos);
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}
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static int proc_mq_dointvec_minmax(ctl_table *table, int write,
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void __user *buffer, size_t *lenp, loff_t *ppos)
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{
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struct ctl_table mq_table;
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memcpy(&mq_table, table, sizeof(mq_table));
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mq_table.data = get_mq(table);
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return proc_dointvec_minmax(&mq_table, write, buffer,
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lenp, ppos);
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}
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#else
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#define proc_mq_dointvec NULL
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#define proc_mq_dointvec_minmax NULL
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#endif
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static int msg_max_limit_min = MIN_MSGMAX;
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static int msg_max_limit_max = HARD_MSGMAX;
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static int msg_maxsize_limit_min = MIN_MSGSIZEMAX;
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static int msg_maxsize_limit_max = HARD_MSGSIZEMAX;
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static ctl_table mq_sysctls[] = {
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{
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.procname = "queues_max",
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.data = &init_ipc_ns.mq_queues_max,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_mq_dointvec,
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},
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{
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.procname = "msg_max",
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.data = &init_ipc_ns.mq_msg_max,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_mq_dointvec_minmax,
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.extra1 = &msg_max_limit_min,
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.extra2 = &msg_max_limit_max,
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},
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{
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.procname = "msgsize_max",
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.data = &init_ipc_ns.mq_msgsize_max,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_mq_dointvec_minmax,
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.extra1 = &msg_maxsize_limit_min,
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.extra2 = &msg_maxsize_limit_max,
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},
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{
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.procname = "msg_default",
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.data = &init_ipc_ns.mq_msg_default,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_mq_dointvec_minmax,
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.extra1 = &msg_max_limit_min,
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.extra2 = &msg_max_limit_max,
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},
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{
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.procname = "msgsize_default",
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.data = &init_ipc_ns.mq_msgsize_default,
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.maxlen = sizeof(int),
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.mode = 0644,
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.proc_handler = proc_mq_dointvec_minmax,
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.extra1 = &msg_maxsize_limit_min,
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.extra2 = &msg_maxsize_limit_max,
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},
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{}
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};
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static ctl_table mq_sysctl_dir[] = {
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{
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.procname = "mqueue",
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.mode = 0555,
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.child = mq_sysctls,
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},
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{}
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};
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static ctl_table mq_sysctl_root[] = {
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{
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.procname = "fs",
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.mode = 0555,
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.child = mq_sysctl_dir,
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},
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{}
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};
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struct ctl_table_header *mq_register_sysctl_table(void)
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{
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return register_sysctl_table(mq_sysctl_root);
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}
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