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ipc/sem.c
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// SPDX-License-Identifier: GPL-2.0 |
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/* * linux/ipc/sem.c * Copyright (C) 1992 Krishna Balasubramanian * Copyright (C) 1995 Eric Schenk, Bruno Haible * |
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* /proc/sysvipc/sem support (c) 1999 Dragos Acostachioaie <dragos@iname.com> * * SMP-threaded, sysctl's added |
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* (c) 1999 Manfred Spraul <manfred@colorfullife.com> |
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* Enforced range limit on SEM_UNDO |
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* (c) 2001 Red Hat Inc |
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* Lockless wakeup * (c) 2003 Manfred Spraul <manfred@colorfullife.com> |
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* (c) 2016 Davidlohr Bueso <dave@stgolabs.net> |
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* Further wakeup optimizations, documentation * (c) 2010 Manfred Spraul <manfred@colorfullife.com> |
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* * support for audit of ipc object properties and permission changes * Dustin Kirkland <dustin.kirkland@us.ibm.com> |
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* * namespaces support * OpenVZ, SWsoft Inc. * Pavel Emelianov <xemul@openvz.org> |
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* * Implementation notes: (May 2010) * This file implements System V semaphores. * * User space visible behavior: * - FIFO ordering for semop() operations (just FIFO, not starvation * protection) * - multiple semaphore operations that alter the same semaphore in * one semop() are handled. * - sem_ctime (time of last semctl()) is updated in the IPC_SET, SETVAL and * SETALL calls. * - two Linux specific semctl() commands: SEM_STAT, SEM_INFO. * - undo adjustments at process exit are limited to 0..SEMVMX. * - namespace are supported. * - SEMMSL, SEMMNS, SEMOPM and SEMMNI can be configured at runtine by writing * to /proc/sys/kernel/sem. * - statistics about the usage are reported in /proc/sysvipc/sem. * * Internals: * - scalability: * - all global variables are read-mostly. * - semop() calls and semctl(RMID) are synchronized by RCU. * - most operations do write operations (actually: spin_lock calls) to * the per-semaphore array structure. * Thus: Perfect SMP scaling between independent semaphore arrays. * If multiple semaphores in one array are used, then cache line * trashing on the semaphore array spinlock will limit the scaling. |
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* - semncnt and semzcnt are calculated on demand in count_semcnt() |
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* - the task that performs a successful semop() scans the list of all * sleeping tasks and completes any pending operations that can be fulfilled. * Semaphores are actively given to waiting tasks (necessary for FIFO). * (see update_queue()) * - To improve the scalability, the actual wake-up calls are performed after |
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* dropping all locks. (see wake_up_sem_queue_prepare()) |
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* - All work is done by the waker, the woken up task does not have to do * anything - not even acquiring a lock or dropping a refcount. * - A woken up task may not even touch the semaphore array anymore, it may * have been destroyed already by a semctl(RMID). |
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* - UNDO values are stored in an array (one per process and per * semaphore array, lazily allocated). For backwards compatibility, multiple * modes for the UNDO variables are supported (per process, per thread) * (see copy_semundo, CLONE_SYSVSEM) * - There are two lists of the pending operations: a per-array list * and per-semaphore list (stored in the array). This allows to achieve FIFO * ordering without always scanning all pending operations. * The worst-case behavior is nevertheless O(N^2) for N wakeups. |
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*/ |
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#include <linux/compat.h> |
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#include <linux/slab.h> #include <linux/spinlock.h> #include <linux/init.h> #include <linux/proc_fs.h> #include <linux/time.h> |
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#include <linux/security.h> #include <linux/syscalls.h> #include <linux/audit.h> |
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#include <linux/capability.h> |
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#include <linux/seq_file.h> |
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#include <linux/rwsem.h> |
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#include <linux/nsproxy.h> |
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#include <linux/ipc_namespace.h> |
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#include <linux/sched/wake_q.h> |
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#include <linux/nospec.h> |
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#include <linux/rhashtable.h> |
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|
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#include <linux/uaccess.h> |
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#include "util.h" |
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/* One semaphore structure for each semaphore in the system. */ struct sem { int semval; /* current value */ /* * PID of the process that last modified the semaphore. For * Linux, specifically these are: * - semop * - semctl, via SETVAL and SETALL. * - at task exit when performing undo adjustments (see exit_sem). */ |
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struct pid *sempid; |
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spinlock_t lock; /* spinlock for fine-grained semtimedop */ struct list_head pending_alter; /* pending single-sop operations */ /* that alter the semaphore */ struct list_head pending_const; /* pending single-sop operations */ /* that do not alter the semaphore*/ |
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time64_t sem_otime; /* candidate for sem_otime */ |
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} ____cacheline_aligned_in_smp; /* One sem_array data structure for each set of semaphores in the system. */ struct sem_array { struct kern_ipc_perm sem_perm; /* permissions .. see ipc.h */ time64_t sem_ctime; /* create/last semctl() time */ struct list_head pending_alter; /* pending operations */ /* that alter the array */ struct list_head pending_const; /* pending complex operations */ /* that do not alter semvals */ struct list_head list_id; /* undo requests on this array */ int sem_nsems; /* no. of semaphores in array */ int complex_count; /* pending complex operations */ unsigned int use_global_lock;/* >0: global lock required */ struct sem sems[]; } __randomize_layout; |
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/* One queue for each sleeping process in the system. */ struct sem_queue { |
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struct list_head list; /* queue of pending operations */ struct task_struct *sleeper; /* this process */ struct sem_undo *undo; /* undo structure */ |
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struct pid *pid; /* process id of requesting process */ |
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int status; /* completion status of operation */ struct sembuf *sops; /* array of pending operations */ |
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struct sembuf *blocking; /* the operation that blocked */ |
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int nsops; /* number of operations */ |
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bool alter; /* does *sops alter the array? */ bool dupsop; /* sops on more than one sem_num */ |
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}; /* Each task has a list of undo requests. They are executed automatically * when the process exits. */ struct sem_undo { struct list_head list_proc; /* per-process list: * * all undos from one process * rcu protected */ struct rcu_head rcu; /* rcu struct for sem_undo */ struct sem_undo_list *ulp; /* back ptr to sem_undo_list */ struct list_head list_id; /* per semaphore array list: * all undos for one array */ int semid; /* semaphore set identifier */ short *semadj; /* array of adjustments */ /* one per semaphore */ }; /* sem_undo_list controls shared access to the list of sem_undo structures * that may be shared among all a CLONE_SYSVSEM task group. */ struct sem_undo_list { |
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refcount_t refcnt; |
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spinlock_t lock; struct list_head list_proc; }; |
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#define sem_ids(ns) ((ns)->ids[IPC_SEM_IDS]) |
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|
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static int newary(struct ipc_namespace *, struct ipc_params *); |
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static void freeary(struct ipc_namespace *, struct kern_ipc_perm *); |
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#ifdef CONFIG_PROC_FS |
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static int sysvipc_sem_proc_show(struct seq_file *s, void *it); |
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#endif #define SEMMSL_FAST 256 /* 512 bytes on stack */ #define SEMOPM_FAST 64 /* ~ 372 bytes on stack */ /* |
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* Switching from the mode suitable for simple ops * to the mode for complex ops is costly. Therefore: * use some hysteresis */ #define USE_GLOBAL_LOCK_HYSTERESIS 10 /* |
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* Locking: |
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* a) global sem_lock() for read/write |
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* sem_undo.id_next, |
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* sem_array.complex_count, |
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* sem_array.pending{_alter,_const}, * sem_array.sem_undo |
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* |
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* b) global or semaphore sem_lock() for read/write: |
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* sem_array.sems[i].pending_{const,alter}: |
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* * c) special: * sem_undo_list.list_proc: * * undo_list->lock for write * * rcu for read |
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* use_global_lock: * * global sem_lock() for write * * either local or global sem_lock() for read. * * Memory ordering: * Most ordering is enforced by using spin_lock() and spin_unlock(). * The special case is use_global_lock: * Setting it from non-zero to 0 is a RELEASE, this is ensured by * using smp_store_release(). * Testing if it is non-zero is an ACQUIRE, this is ensured by using * smp_load_acquire(). * Setting it from 0 to non-zero must be ordered with regards to * this smp_load_acquire(), this is guaranteed because the smp_load_acquire() * is inside a spin_lock() and after a write from 0 to non-zero a * spin_lock()+spin_unlock() is done. |
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*/ |
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#define sc_semmsl sem_ctls[0] #define sc_semmns sem_ctls[1] #define sc_semopm sem_ctls[2] #define sc_semmni sem_ctls[3] |
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void sem_init_ns(struct ipc_namespace *ns) |
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{ |
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ns->sc_semmsl = SEMMSL; ns->sc_semmns = SEMMNS; ns->sc_semopm = SEMOPM; ns->sc_semmni = SEMMNI; ns->used_sems = 0; |
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ipc_init_ids(&ns->ids[IPC_SEM_IDS]); |
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} |
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#ifdef CONFIG_IPC_NS |
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void sem_exit_ns(struct ipc_namespace *ns) { |
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free_ipcs(ns, &sem_ids(ns), freeary); |
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idr_destroy(&ns->ids[IPC_SEM_IDS].ipcs_idr); |
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rhashtable_destroy(&ns->ids[IPC_SEM_IDS].key_ht); |
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} |
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#endif |
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void __init sem_init(void) |
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{ |
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sem_init_ns(&init_ipc_ns); |
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ipc_init_proc_interface("sysvipc/sem", " key semid perms nsems uid gid cuid cgid otime ctime ", |
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IPC_SEM_IDS, sysvipc_sem_proc_show); |
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} |
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/** * unmerge_queues - unmerge queues, if possible. * @sma: semaphore array * * The function unmerges the wait queues if complex_count is 0. * It must be called prior to dropping the global semaphore array lock. */ static void unmerge_queues(struct sem_array *sma) { struct sem_queue *q, *tq; /* complex operations still around? */ if (sma->complex_count) return; /* * We will switch back to simple mode. * Move all pending operation back into the per-semaphore * queues. */ list_for_each_entry_safe(q, tq, &sma->pending_alter, list) { struct sem *curr; |
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curr = &sma->sems[q->sops[0].sem_num]; |
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list_add_tail(&q->list, &curr->pending_alter); } INIT_LIST_HEAD(&sma->pending_alter); } /** |
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* merge_queues - merge single semop queues into global queue |
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* @sma: semaphore array * * This function merges all per-semaphore queues into the global queue. * It is necessary to achieve FIFO ordering for the pending single-sop * operations when a multi-semop operation must sleep. * Only the alter operations must be moved, the const operations can stay. */ static void merge_queues(struct sem_array *sma) { int i; for (i = 0; i < sma->sem_nsems; i++) { |
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struct sem *sem = &sma->sems[i]; |
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list_splice_init(&sem->pending_alter, &sma->pending_alter); } } |
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static void sem_rcu_free(struct rcu_head *head) { |
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struct kern_ipc_perm *p = container_of(head, struct kern_ipc_perm, rcu); struct sem_array *sma = container_of(p, struct sem_array, sem_perm); |
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security_sem_free(&sma->sem_perm); |
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kvfree(sma); |
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} |
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/* |
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* Enter the mode suitable for non-simple operations: |
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* Caller must own sem_perm.lock. |
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*/ |
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static void complexmode_enter(struct sem_array *sma) |
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{ int i; struct sem *sem; |
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if (sma->use_global_lock > 0) { /* * We are already in global lock mode. * Nothing to do, just reset the * counter until we return to simple mode. */ sma->use_global_lock = USE_GLOBAL_LOCK_HYSTERESIS; |
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return; } |
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sma->use_global_lock = USE_GLOBAL_LOCK_HYSTERESIS; |
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|
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for (i = 0; i < sma->sem_nsems; i++) { |
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sem = &sma->sems[i]; |
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spin_lock(&sem->lock); spin_unlock(&sem->lock); |
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} |
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} /* * Try to leave the mode that disallows simple operations: * Caller must own sem_perm.lock. */ static void complexmode_tryleave(struct sem_array *sma) { if (sma->complex_count) { /* Complex ops are sleeping. * We must stay in complex mode */ return; } |
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if (sma->use_global_lock == 1) { /* * Immediately after setting use_global_lock to 0, * a simple op can start. Thus: all memory writes * performed by the current operation must be visible * before we set use_global_lock to 0. */ smp_store_release(&sma->use_global_lock, 0); } else { sma->use_global_lock--; } |
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} |
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#define SEM_GLOBAL_LOCK (-1) |
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/* |
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* If the request contains only one semaphore operation, and there are * no complex transactions pending, lock only the semaphore involved. * Otherwise, lock the entire semaphore array, since we either have * multiple semaphores in our own semops, or we need to look at * semaphores from other pending complex operations. |
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*/ static inline int sem_lock(struct sem_array *sma, struct sembuf *sops, int nsops) { |
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struct sem *sem; |
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int idx; |
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|
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if (nsops != 1) { /* Complex operation - acquire a full lock */ ipc_lock_object(&sma->sem_perm); |
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|
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/* Prevent parallel simple ops */ complexmode_enter(sma); return SEM_GLOBAL_LOCK; |
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} /* * Only one semaphore affected - try to optimize locking. |
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* Optimized locking is possible if no complex operation * is either enqueued or processed right now. * |
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* Both facts are tracked by use_global_mode. |
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*/ |
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idx = array_index_nospec(sops->sem_num, sma->sem_nsems); sem = &sma->sems[idx]; |
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|
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/* |
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* Initial check for use_global_lock. Just an optimization, |
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* no locking, no memory barrier. */ |
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if (!sma->use_global_lock) { |
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/* |
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* It appears that no complex operation is around. * Acquire the per-semaphore lock. |
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*/ |
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spin_lock(&sem->lock); |
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/* pairs with smp_store_release() */ if (!smp_load_acquire(&sma->use_global_lock)) { |
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/* fast path successful! */ return sops->sem_num; |
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} |
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spin_unlock(&sem->lock); } /* slow path: acquire the full lock */ ipc_lock_object(&sma->sem_perm); |
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|
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if (sma->use_global_lock == 0) { /* * The use_global_lock mode ended while we waited for * sma->sem_perm.lock. Thus we must switch to locking * with sem->lock. * Unlike in the fast path, there is no need to recheck * sma->use_global_lock after we have acquired sem->lock: * We own sma->sem_perm.lock, thus use_global_lock cannot * change. |
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*/ spin_lock(&sem->lock); |
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|
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ipc_unlock_object(&sma->sem_perm); return sops->sem_num; |
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} else { |
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/* * Not a false alarm, thus continue to use the global lock * mode. No need for complexmode_enter(), this was done by * the caller that has set use_global_mode to non-zero. |
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*/ |
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return SEM_GLOBAL_LOCK; |
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} |
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} static inline void sem_unlock(struct sem_array *sma, int locknum) { |
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if (locknum == SEM_GLOBAL_LOCK) { |
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unmerge_queues(sma); |
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430 |
complexmode_tryleave(sma); |
cf9d5d78d ipc: close open c... |
431 |
ipc_unlock_object(&sma->sem_perm); |
6062a8dc0 ipc,sem: fine gra... |
432 |
} else { |
1a2339567 ipc/sem.c: remove... |
433 |
struct sem *sem = &sma->sems[locknum]; |
6062a8dc0 ipc,sem: fine gra... |
434 435 |
spin_unlock(&sem->lock); } |
6062a8dc0 ipc,sem: fine gra... |
436 437 438 |
} /* |
d9a605e40 ipc: rename ids->... |
439 |
* sem_lock_(check_) routines are called in the paths where the rwsem |
3e148c799 fix idr_find() lo... |
440 |
* is not held. |
321310ced ipc: move sem_obt... |
441 442 |
* * The caller holds the RCU read lock. |
3e148c799 fix idr_find() lo... |
443 |
*/ |
16df3674e ipc,sem: do not h... |
444 445 |
static inline struct sem_array *sem_obtain_object(struct ipc_namespace *ns, int id) { |
55b7ae501 ipc: rename ipc_o... |
446 |
struct kern_ipc_perm *ipcp = ipc_obtain_object_idr(&sem_ids(ns), id); |
16df3674e ipc,sem: do not h... |
447 448 449 450 451 452 |
if (IS_ERR(ipcp)) return ERR_CAST(ipcp); return container_of(ipcp, struct sem_array, sem_perm); } |
16df3674e ipc,sem: do not h... |
453 454 455 456 457 458 459 |
static inline struct sem_array *sem_obtain_object_check(struct ipc_namespace *ns, int id) { struct kern_ipc_perm *ipcp = ipc_obtain_object_check(&sem_ids(ns), id); if (IS_ERR(ipcp)) return ERR_CAST(ipcp); |
b1ed88b47 IPC: fix error ch... |
460 |
|
03f02c765 Storing ipcs into... |
461 |
return container_of(ipcp, struct sem_array, sem_perm); |
023a53557 ipc: integrate ip... |
462 |
} |
6ff379721 IPC/semaphores: c... |
463 464 |
static inline void sem_lock_and_putref(struct sem_array *sma) { |
6062a8dc0 ipc,sem: fine gra... |
465 |
sem_lock(sma, NULL, -1); |
dba4cdd39 ipc: merge ipc_rc... |
466 |
ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); |
6ff379721 IPC/semaphores: c... |
467 |
} |
7ca7e564e ipc: store ipcs i... |
468 469 470 471 |
static inline void sem_rmid(struct ipc_namespace *ns, struct sem_array *s) { ipc_rmid(&sem_ids(ns), &s->sem_perm); } |
101ede01d ipc/sem: avoid ip... |
472 473 474 475 476 477 478 479 480 481 482 483 484 485 |
static struct sem_array *sem_alloc(size_t nsems) { struct sem_array *sma; size_t size; if (nsems > (INT_MAX - sizeof(*sma)) / sizeof(sma->sems[0])) return NULL; size = sizeof(*sma) + nsems * sizeof(sma->sems[0]); sma = kvmalloc(size, GFP_KERNEL); if (unlikely(!sma)) return NULL; memset(sma, 0, size); |
101ede01d ipc/sem: avoid ip... |
486 487 488 |
return sma; } |
f4566f048 ipc: fix wrong co... |
489 490 491 492 493 |
/** * newary - Create a new semaphore set * @ns: namespace * @params: ptr to the structure that contains key, semflg and nsems * |
d9a605e40 ipc: rename ids->... |
494 |
* Called with sem_ids.rwsem held (as a writer) |
f4566f048 ipc: fix wrong co... |
495 |
*/ |
7748dbfaa ipc: unify the sy... |
496 |
static int newary(struct ipc_namespace *ns, struct ipc_params *params) |
1da177e4c Linux-2.6.12-rc2 |
497 |
{ |
1da177e4c Linux-2.6.12-rc2 |
498 499 |
int retval; struct sem_array *sma; |
7748dbfaa ipc: unify the sy... |
500 501 502 |
key_t key = params->key; int nsems = params->u.nsems; int semflg = params->flg; |
b97e820ff ipc/sem.c: add a ... |
503 |
int i; |
1da177e4c Linux-2.6.12-rc2 |
504 505 506 |
if (!nsems) return -EINVAL; |
e38935341 [PATCH] IPC names... |
507 |
if (ns->used_sems + nsems > ns->sc_semmns) |
1da177e4c Linux-2.6.12-rc2 |
508 |
return -ENOSPC; |
101ede01d ipc/sem: avoid ip... |
509 |
sma = sem_alloc(nsems); |
3ab08fe20 ipc: remove brace... |
510 |
if (!sma) |
1da177e4c Linux-2.6.12-rc2 |
511 |
return -ENOMEM; |
3ab08fe20 ipc: remove brace... |
512 |
|
1da177e4c Linux-2.6.12-rc2 |
513 514 515 516 |
sma->sem_perm.mode = (semflg & S_IRWXUGO); sma->sem_perm.key = key; sma->sem_perm.security = NULL; |
aefad9593 sem/security: Pas... |
517 |
retval = security_sem_alloc(&sma->sem_perm); |
1da177e4c Linux-2.6.12-rc2 |
518 |
if (retval) { |
e2029dfee ipc/sem: drop __s... |
519 |
kvfree(sma); |
1da177e4c Linux-2.6.12-rc2 |
520 521 |
return retval; } |
6062a8dc0 ipc,sem: fine gra... |
522 |
for (i = 0; i < nsems; i++) { |
1a2339567 ipc/sem.c: remove... |
523 524 525 |
INIT_LIST_HEAD(&sma->sems[i].pending_alter); INIT_LIST_HEAD(&sma->sems[i].pending_const); spin_lock_init(&sma->sems[i].lock); |
6062a8dc0 ipc,sem: fine gra... |
526 |
} |
b97e820ff ipc/sem.c: add a ... |
527 528 |
sma->complex_count = 0; |
9de5ab8a2 ipc/sem: add hyst... |
529 |
sma->use_global_lock = USE_GLOBAL_LOCK_HYSTERESIS; |
1a82e9e1d ipc/sem: separate... |
530 531 |
INIT_LIST_HEAD(&sma->pending_alter); INIT_LIST_HEAD(&sma->pending_const); |
4daa28f6d ipc/sem.c: conver... |
532 |
INIT_LIST_HEAD(&sma->list_id); |
1da177e4c Linux-2.6.12-rc2 |
533 |
sma->sem_nsems = nsems; |
e54d02b23 ipc: sem: Make se... |
534 |
sma->sem_ctime = ktime_get_real_seconds(); |
e8577d1f0 ipc/sem.c: fully ... |
535 |
|
39c96a1b9 sysvipc: duplicat... |
536 |
/* ipc_addid() locks sma upon success. */ |
2ec55f802 ipc/sem.c: avoid ... |
537 538 |
retval = ipc_addid(&sem_ids(ns), &sma->sem_perm, ns->sc_semmni); if (retval < 0) { |
39cfffd77 ipc/util.c: use i... |
539 |
ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); |
2ec55f802 ipc/sem.c: avoid ... |
540 |
return retval; |
e8577d1f0 ipc/sem.c: fully ... |
541 542 |
} ns->used_sems += nsems; |
6062a8dc0 ipc,sem: fine gra... |
543 |
sem_unlock(sma, -1); |
6d49dab8a ipc: move rcu_rea... |
544 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
545 |
|
7ca7e564e ipc: store ipcs i... |
546 |
return sma->sem_perm.id; |
1da177e4c Linux-2.6.12-rc2 |
547 |
} |
7748dbfaa ipc: unify the sy... |
548 |
|
f4566f048 ipc: fix wrong co... |
549 |
/* |
d9a605e40 ipc: rename ids->... |
550 |
* Called with sem_ids.rwsem and ipcp locked. |
f4566f048 ipc: fix wrong co... |
551 |
*/ |
03f02c765 Storing ipcs into... |
552 553 |
static inline int sem_more_checks(struct kern_ipc_perm *ipcp, struct ipc_params *params) |
7748dbfaa ipc: unify the sy... |
554 |
{ |
03f02c765 Storing ipcs into... |
555 556 557 558 |
struct sem_array *sma; sma = container_of(ipcp, struct sem_array, sem_perm); if (params->u.nsems > sma->sem_nsems) |
7748dbfaa ipc: unify the sy... |
559 560 561 562 |
return -EINVAL; return 0; } |
69894718a ipc: add semget s... |
563 |
long ksys_semget(key_t key, int nsems, int semflg) |
1da177e4c Linux-2.6.12-rc2 |
564 |
{ |
e38935341 [PATCH] IPC names... |
565 |
struct ipc_namespace *ns; |
eb66ec44f ipc: constify ipc... |
566 567 |
static const struct ipc_ops sem_ops = { .getnew = newary, |
50ab44b1c ipc: Directly cal... |
568 |
.associate = security_sem_associate, |
eb66ec44f ipc: constify ipc... |
569 570 |
.more_checks = sem_more_checks, }; |
7748dbfaa ipc: unify the sy... |
571 |
struct ipc_params sem_params; |
e38935341 [PATCH] IPC names... |
572 573 |
ns = current->nsproxy->ipc_ns; |
1da177e4c Linux-2.6.12-rc2 |
574 |
|
e38935341 [PATCH] IPC names... |
575 |
if (nsems < 0 || nsems > ns->sc_semmsl) |
1da177e4c Linux-2.6.12-rc2 |
576 |
return -EINVAL; |
7ca7e564e ipc: store ipcs i... |
577 |
|
7748dbfaa ipc: unify the sy... |
578 579 580 |
sem_params.key = key; sem_params.flg = semflg; sem_params.u.nsems = nsems; |
1da177e4c Linux-2.6.12-rc2 |
581 |
|
7748dbfaa ipc: unify the sy... |
582 |
return ipcget(ns, &sem_ids(ns), &sem_ops, &sem_params); |
1da177e4c Linux-2.6.12-rc2 |
583 |
} |
69894718a ipc: add semget s... |
584 585 586 587 |
SYSCALL_DEFINE3(semget, key_t, key, int, nsems, int, semflg) { return ksys_semget(key, nsems, semflg); } |
78f5009cc ipc/sem.c: avoid ... |
588 |
/** |
4ce33ec2e ipc/sem: optimize... |
589 590 |
* perform_atomic_semop[_slow] - Attempt to perform semaphore * operations on a given array. |
758a6ba39 ipc/sem.c: rename... |
591 |
* @sma: semaphore array |
d198cd6d6 ipc/sem.c: change... |
592 |
* @q: struct sem_queue that describes the operation |
758a6ba39 ipc/sem.c: rename... |
593 |
* |
4ce33ec2e ipc/sem: optimize... |
594 595 596 597 598 599 600 |
* Caller blocking are as follows, based the value * indicated by the semaphore operation (sem_op): * * (1) >0 never blocks. * (2) 0 (wait-for-zero operation): semval is non-zero. * (3) <0 attempting to decrement semval to a value smaller than zero. * |
758a6ba39 ipc/sem.c: rename... |
601 602 |
* Returns 0 if the operation was possible. * Returns 1 if the operation is impossible, the caller must sleep. |
4ce33ec2e ipc/sem: optimize... |
603 |
* Returns <0 for error codes. |
1da177e4c Linux-2.6.12-rc2 |
604 |
*/ |
4ce33ec2e ipc/sem: optimize... |
605 |
static int perform_atomic_semop_slow(struct sem_array *sma, struct sem_queue *q) |
1da177e4c Linux-2.6.12-rc2 |
606 |
{ |
51d6f2635 ipc/sem: Fix semc... |
607 608 |
int result, sem_op, nsops; struct pid *pid; |
1da177e4c Linux-2.6.12-rc2 |
609 |
struct sembuf *sop; |
239521f31 ipc: whitespace c... |
610 |
struct sem *curr; |
d198cd6d6 ipc/sem.c: change... |
611 612 613 614 615 616 |
struct sembuf *sops; struct sem_undo *un; sops = q->sops; nsops = q->nsops; un = q->undo; |
1da177e4c Linux-2.6.12-rc2 |
617 618 |
for (sop = sops; sop < sops + nsops; sop++) { |
ec67aaa46 sysvipc/sem: miti... |
619 620 |
int idx = array_index_nospec(sop->sem_num, sma->sem_nsems); curr = &sma->sems[idx]; |
1da177e4c Linux-2.6.12-rc2 |
621 622 |
sem_op = sop->sem_op; result = curr->semval; |
78f5009cc ipc/sem.c: avoid ... |
623 |
|
1da177e4c Linux-2.6.12-rc2 |
624 625 626 627 628 629 630 631 |
if (!sem_op && result) goto would_block; result += sem_op; if (result < 0) goto would_block; if (result > SEMVMX) goto out_of_range; |
78f5009cc ipc/sem.c: avoid ... |
632 |
|
1da177e4c Linux-2.6.12-rc2 |
633 634 |
if (sop->sem_flg & SEM_UNDO) { int undo = un->semadj[sop->sem_num] - sem_op; |
78f5009cc ipc/sem.c: avoid ... |
635 |
/* Exceeding the undo range is an error. */ |
1da177e4c Linux-2.6.12-rc2 |
636 637 |
if (undo < (-SEMAEM - 1) || undo > SEMAEM) goto out_of_range; |
78f5009cc ipc/sem.c: avoid ... |
638 |
un->semadj[sop->sem_num] = undo; |
1da177e4c Linux-2.6.12-rc2 |
639 |
} |
78f5009cc ipc/sem.c: avoid ... |
640 |
|
1da177e4c Linux-2.6.12-rc2 |
641 642 643 644 |
curr->semval = result; } sop--; |
d198cd6d6 ipc/sem.c: change... |
645 |
pid = q->pid; |
1da177e4c Linux-2.6.12-rc2 |
646 |
while (sop >= sops) { |
51d6f2635 ipc/sem: Fix semc... |
647 |
ipc_update_pid(&sma->sems[sop->sem_num].sempid, pid); |
1da177e4c Linux-2.6.12-rc2 |
648 649 |
sop--; } |
78f5009cc ipc/sem.c: avoid ... |
650 |
|
1da177e4c Linux-2.6.12-rc2 |
651 652 653 654 655 656 657 |
return 0; out_of_range: result = -ERANGE; goto undo; would_block: |
ed247b7ca ipc/sem.c: store ... |
658 |
q->blocking = sop; |
1da177e4c Linux-2.6.12-rc2 |
659 660 661 662 663 664 665 666 |
if (sop->sem_flg & IPC_NOWAIT) result = -EAGAIN; else result = 1; undo: sop--; while (sop >= sops) { |
78f5009cc ipc/sem.c: avoid ... |
667 |
sem_op = sop->sem_op; |
1a2339567 ipc/sem.c: remove... |
668 |
sma->sems[sop->sem_num].semval -= sem_op; |
78f5009cc ipc/sem.c: avoid ... |
669 670 |
if (sop->sem_flg & SEM_UNDO) un->semadj[sop->sem_num] += sem_op; |
1da177e4c Linux-2.6.12-rc2 |
671 672 673 674 675 |
sop--; } return result; } |
4ce33ec2e ipc/sem: optimize... |
676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 |
static int perform_atomic_semop(struct sem_array *sma, struct sem_queue *q) { int result, sem_op, nsops; struct sembuf *sop; struct sem *curr; struct sembuf *sops; struct sem_undo *un; sops = q->sops; nsops = q->nsops; un = q->undo; if (unlikely(q->dupsop)) return perform_atomic_semop_slow(sma, q); /* * We scan the semaphore set twice, first to ensure that the entire * operation can succeed, therefore avoiding any pointless writes * to shared memory and having to undo such changes in order to block * until the operations can go through. */ for (sop = sops; sop < sops + nsops; sop++) { |
ec67aaa46 sysvipc/sem: miti... |
698 699 700 |
int idx = array_index_nospec(sop->sem_num, sma->sem_nsems); curr = &sma->sems[idx]; |
4ce33ec2e ipc/sem: optimize... |
701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 |
sem_op = sop->sem_op; result = curr->semval; if (!sem_op && result) goto would_block; /* wait-for-zero */ result += sem_op; if (result < 0) goto would_block; if (result > SEMVMX) return -ERANGE; if (sop->sem_flg & SEM_UNDO) { int undo = un->semadj[sop->sem_num] - sem_op; /* Exceeding the undo range is an error. */ if (undo < (-SEMAEM - 1) || undo > SEMAEM) return -ERANGE; } } for (sop = sops; sop < sops + nsops; sop++) { |
1a2339567 ipc/sem.c: remove... |
724 |
curr = &sma->sems[sop->sem_num]; |
4ce33ec2e ipc/sem: optimize... |
725 726 727 728 729 730 731 732 733 |
sem_op = sop->sem_op; result = curr->semval; if (sop->sem_flg & SEM_UNDO) { int undo = un->semadj[sop->sem_num] - sem_op; un->semadj[sop->sem_num] = undo; } curr->semval += sem_op; |
51d6f2635 ipc/sem: Fix semc... |
734 |
ipc_update_pid(&curr->sempid, q->pid); |
4ce33ec2e ipc/sem: optimize... |
735 736 737 738 739 740 741 742 |
} return 0; would_block: q->blocking = sop; return sop->sem_flg & IPC_NOWAIT ? -EAGAIN : 1; } |
9ae949fa3 ipc/sem: rework t... |
743 744 |
static inline void wake_up_sem_queue_prepare(struct sem_queue *q, int error, struct wake_q_head *wake_q) |
0a2b9d4c7 ipc/sem.c: move w... |
745 |
{ |
9ae949fa3 ipc/sem: rework t... |
746 747 748 749 750 751 752 753 754 |
wake_q_add(wake_q, q->sleeper); /* * Rely on the above implicit barrier, such that we can * ensure that we hold reference to the task before setting * q->status. Otherwise we could race with do_exit if the * task is awoken by an external event before calling * wake_up_process(). */ WRITE_ONCE(q->status, error); |
d4212093d ipc/sem.c: sem pr... |
755 |
} |
b97e820ff ipc/sem.c: add a ... |
756 757 758 |
static void unlink_queue(struct sem_array *sma, struct sem_queue *q) { list_del(&q->list); |
9f1bc2c90 ipc,sem: have onl... |
759 |
if (q->nsops > 1) |
b97e820ff ipc/sem.c: add a ... |
760 761 |
sma->complex_count--; } |
fd5db4225 ipc/sem.c: optimi... |
762 763 764 765 766 767 768 |
/** check_restart(sma, q) * @sma: semaphore array * @q: the operation that just completed * * update_queue is O(N^2) when it restarts scanning the whole queue of * waiting operations. Therefore this function checks if the restart is * really necessary. It is called after a previously waiting operation |
1a82e9e1d ipc/sem: separate... |
769 770 |
* modified the array. * Note that wait-for-zero operations are handled without restart. |
fd5db4225 ipc/sem.c: optimi... |
771 |
*/ |
4663d3e8f ipc/sem: explicit... |
772 |
static inline int check_restart(struct sem_array *sma, struct sem_queue *q) |
fd5db4225 ipc/sem.c: optimi... |
773 |
{ |
1a82e9e1d ipc/sem: separate... |
774 775 |
/* pending complex alter operations are too difficult to analyse */ if (!list_empty(&sma->pending_alter)) |
fd5db4225 ipc/sem.c: optimi... |
776 777 778 779 780 |
return 1; /* we were a sleeping complex operation. Too difficult */ if (q->nsops > 1) return 1; |
1a82e9e1d ipc/sem: separate... |
781 782 783 784 785 786 787 788 789 790 791 792 793 |
/* It is impossible that someone waits for the new value: * - complex operations always restart. * - wait-for-zero are handled seperately. * - q is a previously sleeping simple operation that * altered the array. It must be a decrement, because * simple increments never sleep. * - If there are older (higher priority) decrements * in the queue, then they have observed the original * semval value and couldn't proceed. The operation * decremented to value - thus they won't proceed either. */ return 0; } |
fd5db4225 ipc/sem.c: optimi... |
794 |
|
1a82e9e1d ipc/sem: separate... |
795 |
/** |
8001c8581 ipc: standardize ... |
796 |
* wake_const_ops - wake up non-alter tasks |
1a82e9e1d ipc/sem: separate... |
797 798 |
* @sma: semaphore array. * @semnum: semaphore that was modified. |
9ae949fa3 ipc/sem: rework t... |
799 |
* @wake_q: lockless wake-queue head. |
1a82e9e1d ipc/sem: separate... |
800 801 802 803 804 |
* * wake_const_ops must be called after a semaphore in a semaphore array * was set to 0. If complex const operations are pending, wake_const_ops must * be called with semnum = -1, as well as with the number of each modified * semaphore. |
9ae949fa3 ipc/sem: rework t... |
805 |
* The tasks that must be woken up are added to @wake_q. The return code |
1a82e9e1d ipc/sem: separate... |
806 807 808 809 |
* is stored in q->pid. * The function returns 1 if at least one operation was completed successfully. */ static int wake_const_ops(struct sem_array *sma, int semnum, |
9ae949fa3 ipc/sem: rework t... |
810 |
struct wake_q_head *wake_q) |
1a82e9e1d ipc/sem: separate... |
811 |
{ |
f150f02cf ipc/sem: use prop... |
812 |
struct sem_queue *q, *tmp; |
1a82e9e1d ipc/sem: separate... |
813 814 815 816 817 818 |
struct list_head *pending_list; int semop_completed = 0; if (semnum == -1) pending_list = &sma->pending_const; else |
1a2339567 ipc/sem.c: remove... |
819 |
pending_list = &sma->sems[semnum].pending_const; |
fd5db4225 ipc/sem.c: optimi... |
820 |
|
f150f02cf ipc/sem: use prop... |
821 822 |
list_for_each_entry_safe(q, tmp, pending_list, list) { int error = perform_atomic_semop(sma, q); |
1a82e9e1d ipc/sem: separate... |
823 |
|
f150f02cf ipc/sem: use prop... |
824 825 826 827 |
if (error > 0) continue; /* operation completed, remove from queue & wakeup */ unlink_queue(sma, q); |
1a82e9e1d ipc/sem: separate... |
828 |
|
f150f02cf ipc/sem: use prop... |
829 830 831 |
wake_up_sem_queue_prepare(q, error, wake_q); if (error == 0) semop_completed = 1; |
1a82e9e1d ipc/sem: separate... |
832 |
} |
f150f02cf ipc/sem: use prop... |
833 |
|
1a82e9e1d ipc/sem: separate... |
834 835 836 837 |
return semop_completed; } /** |
8001c8581 ipc: standardize ... |
838 |
* do_smart_wakeup_zero - wakeup all wait for zero tasks |
1a82e9e1d ipc/sem: separate... |
839 840 841 |
* @sma: semaphore array * @sops: operations that were performed * @nsops: number of operations |
9ae949fa3 ipc/sem: rework t... |
842 |
* @wake_q: lockless wake-queue head |
1a82e9e1d ipc/sem: separate... |
843 |
* |
8001c8581 ipc: standardize ... |
844 845 |
* Checks all required queue for wait-for-zero operations, based * on the actual changes that were performed on the semaphore array. |
1a82e9e1d ipc/sem: separate... |
846 847 848 |
* The function returns 1 if at least one operation was completed successfully. */ static int do_smart_wakeup_zero(struct sem_array *sma, struct sembuf *sops, |
9ae949fa3 ipc/sem: rework t... |
849 |
int nsops, struct wake_q_head *wake_q) |
1a82e9e1d ipc/sem: separate... |
850 851 852 853 854 855 856 857 858 |
{ int i; int semop_completed = 0; int got_zero = 0; /* first: the per-semaphore queues, if known */ if (sops) { for (i = 0; i < nsops; i++) { int num = sops[i].sem_num; |
1a2339567 ipc/sem.c: remove... |
859 |
if (sma->sems[num].semval == 0) { |
1a82e9e1d ipc/sem: separate... |
860 |
got_zero = 1; |
9ae949fa3 ipc/sem: rework t... |
861 |
semop_completed |= wake_const_ops(sma, num, wake_q); |
1a82e9e1d ipc/sem: separate... |
862 863 864 865 866 867 |
} } } else { /* * No sops means modified semaphores not known. * Assume all were changed. |
fd5db4225 ipc/sem.c: optimi... |
868 |
*/ |
1a82e9e1d ipc/sem: separate... |
869 |
for (i = 0; i < sma->sem_nsems; i++) { |
1a2339567 ipc/sem.c: remove... |
870 |
if (sma->sems[i].semval == 0) { |
1a82e9e1d ipc/sem: separate... |
871 |
got_zero = 1; |
9ae949fa3 ipc/sem: rework t... |
872 |
semop_completed |= wake_const_ops(sma, i, wake_q); |
1a82e9e1d ipc/sem: separate... |
873 874 |
} } |
fd5db4225 ipc/sem.c: optimi... |
875 876 |
} /* |
1a82e9e1d ipc/sem: separate... |
877 878 |
* If one of the modified semaphores got 0, * then check the global queue, too. |
fd5db4225 ipc/sem.c: optimi... |
879 |
*/ |
1a82e9e1d ipc/sem: separate... |
880 |
if (got_zero) |
9ae949fa3 ipc/sem: rework t... |
881 |
semop_completed |= wake_const_ops(sma, -1, wake_q); |
fd5db4225 ipc/sem.c: optimi... |
882 |
|
1a82e9e1d ipc/sem: separate... |
883 |
return semop_completed; |
fd5db4225 ipc/sem.c: optimi... |
884 |
} |
636c6be82 ipc/sem.c: optimi... |
885 886 |
/** |
8001c8581 ipc: standardize ... |
887 |
* update_queue - look for tasks that can be completed. |
636c6be82 ipc/sem.c: optimi... |
888 889 |
* @sma: semaphore array. * @semnum: semaphore that was modified. |
9ae949fa3 ipc/sem: rework t... |
890 |
* @wake_q: lockless wake-queue head. |
636c6be82 ipc/sem.c: optimi... |
891 892 |
* * update_queue must be called after a semaphore in a semaphore array |
9f1bc2c90 ipc,sem: have onl... |
893 894 895 |
* was modified. If multiple semaphores were modified, update_queue must * be called with semnum = -1, as well as with the number of each modified * semaphore. |
9ae949fa3 ipc/sem: rework t... |
896 |
* The tasks that must be woken up are added to @wake_q. The return code |
0a2b9d4c7 ipc/sem.c: move w... |
897 |
* is stored in q->pid. |
1a82e9e1d ipc/sem: separate... |
898 899 |
* The function internally checks if const operations can now succeed. * |
0a2b9d4c7 ipc/sem.c: move w... |
900 |
* The function return 1 if at least one semop was completed successfully. |
1da177e4c Linux-2.6.12-rc2 |
901 |
*/ |
9ae949fa3 ipc/sem: rework t... |
902 |
static int update_queue(struct sem_array *sma, int semnum, struct wake_q_head *wake_q) |
1da177e4c Linux-2.6.12-rc2 |
903 |
{ |
f150f02cf ipc/sem: use prop... |
904 |
struct sem_queue *q, *tmp; |
636c6be82 ipc/sem.c: optimi... |
905 |
struct list_head *pending_list; |
0a2b9d4c7 ipc/sem.c: move w... |
906 |
int semop_completed = 0; |
636c6be82 ipc/sem.c: optimi... |
907 |
|
9f1bc2c90 ipc,sem: have onl... |
908 |
if (semnum == -1) |
1a82e9e1d ipc/sem: separate... |
909 |
pending_list = &sma->pending_alter; |
9f1bc2c90 ipc,sem: have onl... |
910 |
else |
1a2339567 ipc/sem.c: remove... |
911 |
pending_list = &sma->sems[semnum].pending_alter; |
9cad200c7 ipc/sem.c: sem us... |
912 913 |
again: |
f150f02cf ipc/sem: use prop... |
914 |
list_for_each_entry_safe(q, tmp, pending_list, list) { |
fd5db4225 ipc/sem.c: optimi... |
915 |
int error, restart; |
636c6be82 ipc/sem.c: optimi... |
916 |
|
d987f8b21 ipc/sem.c: optimi... |
917 918 |
/* If we are scanning the single sop, per-semaphore list of * one semaphore and that semaphore is 0, then it is not |
1a82e9e1d ipc/sem: separate... |
919 |
* necessary to scan further: simple increments |
d987f8b21 ipc/sem.c: optimi... |
920 921 922 923 |
* that affect only one entry succeed immediately and cannot * be in the per semaphore pending queue, and decrements * cannot be successful if the value is already 0. */ |
1a2339567 ipc/sem.c: remove... |
924 |
if (semnum != -1 && sma->sems[semnum].semval == 0) |
d987f8b21 ipc/sem.c: optimi... |
925 |
break; |
d198cd6d6 ipc/sem.c: change... |
926 |
error = perform_atomic_semop(sma, q); |
1da177e4c Linux-2.6.12-rc2 |
927 928 |
/* Does q->sleeper still need to sleep? */ |
9cad200c7 ipc/sem.c: sem us... |
929 930 |
if (error > 0) continue; |
b97e820ff ipc/sem.c: add a ... |
931 |
unlink_queue(sma, q); |
9cad200c7 ipc/sem.c: sem us... |
932 |
|
0a2b9d4c7 ipc/sem.c: move w... |
933 |
if (error) { |
fd5db4225 ipc/sem.c: optimi... |
934 |
restart = 0; |
0a2b9d4c7 ipc/sem.c: move w... |
935 936 |
} else { semop_completed = 1; |
9ae949fa3 ipc/sem: rework t... |
937 |
do_smart_wakeup_zero(sma, q->sops, q->nsops, wake_q); |
fd5db4225 ipc/sem.c: optimi... |
938 |
restart = check_restart(sma, q); |
0a2b9d4c7 ipc/sem.c: move w... |
939 |
} |
fd5db4225 ipc/sem.c: optimi... |
940 |
|
9ae949fa3 ipc/sem: rework t... |
941 |
wake_up_sem_queue_prepare(q, error, wake_q); |
fd5db4225 ipc/sem.c: optimi... |
942 |
if (restart) |
9cad200c7 ipc/sem.c: sem us... |
943 |
goto again; |
1da177e4c Linux-2.6.12-rc2 |
944 |
} |
0a2b9d4c7 ipc/sem.c: move w... |
945 |
return semop_completed; |
1da177e4c Linux-2.6.12-rc2 |
946 |
} |
0a2b9d4c7 ipc/sem.c: move w... |
947 |
/** |
8001c8581 ipc: standardize ... |
948 |
* set_semotime - set sem_otime |
0e8c66569 ipc/sem.c: update... |
949 950 951 952 953 954 955 956 957 |
* @sma: semaphore array * @sops: operations that modified the array, may be NULL * * sem_otime is replicated to avoid cache line trashing. * This function sets one instance to the current time. */ static void set_semotime(struct sem_array *sma, struct sembuf *sops) { if (sops == NULL) { |
2a70b7879 y2038: ipc: Use k... |
958 |
sma->sems[0].sem_otime = ktime_get_real_seconds(); |
0e8c66569 ipc/sem.c: update... |
959 |
} else { |
1a2339567 ipc/sem.c: remove... |
960 |
sma->sems[sops[0].sem_num].sem_otime = |
2a70b7879 y2038: ipc: Use k... |
961 |
ktime_get_real_seconds(); |
0e8c66569 ipc/sem.c: update... |
962 963 964 965 |
} } /** |
8001c8581 ipc: standardize ... |
966 |
* do_smart_update - optimized update_queue |
fd5db4225 ipc/sem.c: optimi... |
967 968 969 |
* @sma: semaphore array * @sops: operations that were performed * @nsops: number of operations |
0a2b9d4c7 ipc/sem.c: move w... |
970 |
* @otime: force setting otime |
9ae949fa3 ipc/sem: rework t... |
971 |
* @wake_q: lockless wake-queue head |
fd5db4225 ipc/sem.c: optimi... |
972 |
* |
1a82e9e1d ipc/sem: separate... |
973 974 |
* do_smart_update() does the required calls to update_queue and wakeup_zero, * based on the actual changes that were performed on the semaphore array. |
0a2b9d4c7 ipc/sem.c: move w... |
975 |
* Note that the function does not do the actual wake-up: the caller is |
9ae949fa3 ipc/sem: rework t... |
976 |
* responsible for calling wake_up_q(). |
0a2b9d4c7 ipc/sem.c: move w... |
977 |
* It is safe to perform this call after dropping all locks. |
fd5db4225 ipc/sem.c: optimi... |
978 |
*/ |
0a2b9d4c7 ipc/sem.c: move w... |
979 |
static void do_smart_update(struct sem_array *sma, struct sembuf *sops, int nsops, |
9ae949fa3 ipc/sem: rework t... |
980 |
int otime, struct wake_q_head *wake_q) |
fd5db4225 ipc/sem.c: optimi... |
981 982 |
{ int i; |
9ae949fa3 ipc/sem: rework t... |
983 |
otime |= do_smart_wakeup_zero(sma, sops, nsops, wake_q); |
1a82e9e1d ipc/sem: separate... |
984 |
|
f269f40ad ipc/sem.c: always... |
985 986 |
if (!list_empty(&sma->pending_alter)) { /* semaphore array uses the global queue - just process it. */ |
9ae949fa3 ipc/sem: rework t... |
987 |
otime |= update_queue(sma, -1, wake_q); |
f269f40ad ipc/sem.c: always... |
988 989 990 991 992 993 994 |
} else { if (!sops) { /* * No sops, thus the modified semaphores are not * known. Check all. */ for (i = 0; i < sma->sem_nsems; i++) |
9ae949fa3 ipc/sem: rework t... |
995 |
otime |= update_queue(sma, i, wake_q); |
f269f40ad ipc/sem.c: always... |
996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 |
} else { /* * Check the semaphores that were increased: * - No complex ops, thus all sleeping ops are * decrease. * - if we decreased the value, then any sleeping * semaphore ops wont be able to run: If the * previous value was too small, then the new * value will be too small, too. */ for (i = 0; i < nsops; i++) { if (sops[i].sem_op > 0) { otime |= update_queue(sma, |
9ae949fa3 ipc/sem: rework t... |
1009 |
sops[i].sem_num, wake_q); |
f269f40ad ipc/sem.c: always... |
1010 |
} |
ab465df9d ipc/sem.c: Fix mi... |
1011 |
} |
9f1bc2c90 ipc,sem: have onl... |
1012 |
} |
fd5db4225 ipc/sem.c: optimi... |
1013 |
} |
0e8c66569 ipc/sem.c: update... |
1014 1015 |
if (otime) set_semotime(sma, sops); |
fd5db4225 ipc/sem.c: optimi... |
1016 |
} |
2f2ed41dc ipc/sem.c: remove... |
1017 |
/* |
b220c57ae ipc/sem.c: make s... |
1018 |
* check_qop: Test if a queued operation sleeps on the semaphore semnum |
2f2ed41dc ipc/sem.c: remove... |
1019 1020 1021 1022 |
*/ static int check_qop(struct sem_array *sma, int semnum, struct sem_queue *q, bool count_zero) { |
b220c57ae ipc/sem.c: make s... |
1023 |
struct sembuf *sop = q->blocking; |
2f2ed41dc ipc/sem.c: remove... |
1024 |
|
9b44ee2ee ipc/sem.c: add a ... |
1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 |
/* * Linux always (since 0.99.10) reported a task as sleeping on all * semaphores. This violates SUS, therefore it was changed to the * standard compliant behavior. * Give the administrators a chance to notice that an application * might misbehave because it relies on the Linux behavior. */ pr_info_once("semctl(GETNCNT/GETZCNT) is since 3.16 Single Unix Specification compliant. " "The task %s (%d) triggered the difference, watch for misbehavior. ", current->comm, task_pid_nr(current)); |
b220c57ae ipc/sem.c: make s... |
1037 1038 |
if (sop->sem_num != semnum) return 0; |
2f2ed41dc ipc/sem.c: remove... |
1039 |
|
b220c57ae ipc/sem.c: make s... |
1040 1041 1042 1043 1044 1045 |
if (count_zero && sop->sem_op == 0) return 1; if (!count_zero && sop->sem_op < 0) return 1; return 0; |
2f2ed41dc ipc/sem.c: remove... |
1046 |
} |
1da177e4c Linux-2.6.12-rc2 |
1047 1048 1049 |
/* The following counts are associated to each semaphore: * semncnt number of tasks waiting on semval being nonzero * semzcnt number of tasks waiting on semval being zero |
b220c57ae ipc/sem.c: make s... |
1050 1051 1052 |
* * Per definition, a task waits only on the semaphore of the first semop * that cannot proceed, even if additional operation would block, too. |
1da177e4c Linux-2.6.12-rc2 |
1053 |
*/ |
2f2ed41dc ipc/sem.c: remove... |
1054 1055 |
static int count_semcnt(struct sem_array *sma, ushort semnum, bool count_zero) |
1da177e4c Linux-2.6.12-rc2 |
1056 |
{ |
2f2ed41dc ipc/sem.c: remove... |
1057 |
struct list_head *l; |
239521f31 ipc: whitespace c... |
1058 |
struct sem_queue *q; |
2f2ed41dc ipc/sem.c: remove... |
1059 |
int semcnt; |
1da177e4c Linux-2.6.12-rc2 |
1060 |
|
2f2ed41dc ipc/sem.c: remove... |
1061 1062 1063 |
semcnt = 0; /* First: check the simple operations. They are easy to evaluate */ if (count_zero) |
1a2339567 ipc/sem.c: remove... |
1064 |
l = &sma->sems[semnum].pending_const; |
2f2ed41dc ipc/sem.c: remove... |
1065 |
else |
1a2339567 ipc/sem.c: remove... |
1066 |
l = &sma->sems[semnum].pending_alter; |
1da177e4c Linux-2.6.12-rc2 |
1067 |
|
2f2ed41dc ipc/sem.c: remove... |
1068 1069 1070 1071 1072 |
list_for_each_entry(q, l, list) { /* all task on a per-semaphore list sleep on exactly * that semaphore */ semcnt++; |
ebc2e5e6a ipc,sem: fix semc... |
1073 |
} |
2f2ed41dc ipc/sem.c: remove... |
1074 |
/* Then: check the complex operations. */ |
1994862dc ipc/sem.c: bugfix... |
1075 |
list_for_each_entry(q, &sma->pending_alter, list) { |
2f2ed41dc ipc/sem.c: remove... |
1076 1077 1078 1079 1080 1081 |
semcnt += check_qop(sma, semnum, q, count_zero); } if (count_zero) { list_for_each_entry(q, &sma->pending_const, list) { semcnt += check_qop(sma, semnum, q, count_zero); } |
1994862dc ipc/sem.c: bugfix... |
1082 |
} |
2f2ed41dc ipc/sem.c: remove... |
1083 |
return semcnt; |
1da177e4c Linux-2.6.12-rc2 |
1084 |
} |
d9a605e40 ipc: rename ids->... |
1085 1086 |
/* Free a semaphore set. freeary() is called with sem_ids.rwsem locked * as a writer and the spinlock for this semaphore set hold. sem_ids.rwsem |
3e148c799 fix idr_find() lo... |
1087 |
* remains locked on exit. |
1da177e4c Linux-2.6.12-rc2 |
1088 |
*/ |
01b8b07a5 IPC: consolidate ... |
1089 |
static void freeary(struct ipc_namespace *ns, struct kern_ipc_perm *ipcp) |
1da177e4c Linux-2.6.12-rc2 |
1090 |
{ |
380af1b33 ipc/sem.c: rewrit... |
1091 1092 |
struct sem_undo *un, *tu; struct sem_queue *q, *tq; |
01b8b07a5 IPC: consolidate ... |
1093 |
struct sem_array *sma = container_of(ipcp, struct sem_array, sem_perm); |
9f1bc2c90 ipc,sem: have onl... |
1094 |
int i; |
9ae949fa3 ipc/sem: rework t... |
1095 |
DEFINE_WAKE_Q(wake_q); |
1da177e4c Linux-2.6.12-rc2 |
1096 |
|
380af1b33 ipc/sem.c: rewrit... |
1097 |
/* Free the existing undo structures for this semaphore set. */ |
cf9d5d78d ipc: close open c... |
1098 |
ipc_assert_locked_object(&sma->sem_perm); |
380af1b33 ipc/sem.c: rewrit... |
1099 1100 1101 |
list_for_each_entry_safe(un, tu, &sma->list_id, list_id) { list_del(&un->list_id); spin_lock(&un->ulp->lock); |
1da177e4c Linux-2.6.12-rc2 |
1102 |
un->semid = -1; |
380af1b33 ipc/sem.c: rewrit... |
1103 1104 |
list_del_rcu(&un->list_proc); spin_unlock(&un->ulp->lock); |
693a8b6ee ipc,rcu: Convert ... |
1105 |
kfree_rcu(un, rcu); |
380af1b33 ipc/sem.c: rewrit... |
1106 |
} |
1da177e4c Linux-2.6.12-rc2 |
1107 1108 |
/* Wake up all pending processes and let them fail with EIDRM. */ |
1a82e9e1d ipc/sem: separate... |
1109 1110 |
list_for_each_entry_safe(q, tq, &sma->pending_const, list) { unlink_queue(sma, q); |
9ae949fa3 ipc/sem: rework t... |
1111 |
wake_up_sem_queue_prepare(q, -EIDRM, &wake_q); |
1a82e9e1d ipc/sem: separate... |
1112 1113 1114 |
} list_for_each_entry_safe(q, tq, &sma->pending_alter, list) { |
b97e820ff ipc/sem.c: add a ... |
1115 |
unlink_queue(sma, q); |
9ae949fa3 ipc/sem: rework t... |
1116 |
wake_up_sem_queue_prepare(q, -EIDRM, &wake_q); |
1da177e4c Linux-2.6.12-rc2 |
1117 |
} |
9f1bc2c90 ipc,sem: have onl... |
1118 |
for (i = 0; i < sma->sem_nsems; i++) { |
1a2339567 ipc/sem.c: remove... |
1119 |
struct sem *sem = &sma->sems[i]; |
1a82e9e1d ipc/sem: separate... |
1120 1121 |
list_for_each_entry_safe(q, tq, &sem->pending_const, list) { unlink_queue(sma, q); |
9ae949fa3 ipc/sem: rework t... |
1122 |
wake_up_sem_queue_prepare(q, -EIDRM, &wake_q); |
1a82e9e1d ipc/sem: separate... |
1123 1124 |
} list_for_each_entry_safe(q, tq, &sem->pending_alter, list) { |
9f1bc2c90 ipc,sem: have onl... |
1125 |
unlink_queue(sma, q); |
9ae949fa3 ipc/sem: rework t... |
1126 |
wake_up_sem_queue_prepare(q, -EIDRM, &wake_q); |
9f1bc2c90 ipc,sem: have onl... |
1127 |
} |
51d6f2635 ipc/sem: Fix semc... |
1128 |
ipc_update_pid(&sem->sempid, NULL); |
9f1bc2c90 ipc,sem: have onl... |
1129 |
} |
1da177e4c Linux-2.6.12-rc2 |
1130 |
|
7ca7e564e ipc: store ipcs i... |
1131 1132 |
/* Remove the semaphore set from the IDR */ sem_rmid(ns, sma); |
6062a8dc0 ipc,sem: fine gra... |
1133 |
sem_unlock(sma, -1); |
6d49dab8a ipc: move rcu_rea... |
1134 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
1135 |
|
9ae949fa3 ipc/sem: rework t... |
1136 |
wake_up_q(&wake_q); |
e38935341 [PATCH] IPC names... |
1137 |
ns->used_sems -= sma->sem_nsems; |
dba4cdd39 ipc: merge ipc_rc... |
1138 |
ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); |
1da177e4c Linux-2.6.12-rc2 |
1139 1140 1141 1142 |
} static unsigned long copy_semid_to_user(void __user *buf, struct semid64_ds *in, int version) { |
239521f31 ipc: whitespace c... |
1143 |
switch (version) { |
1da177e4c Linux-2.6.12-rc2 |
1144 1145 1146 1147 1148 |
case IPC_64: return copy_to_user(buf, in, sizeof(*in)); case IPC_OLD: { struct semid_ds out; |
982f7c2b2 sys_semctl: fix k... |
1149 |
memset(&out, 0, sizeof(out)); |
1da177e4c Linux-2.6.12-rc2 |
1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 |
ipc64_perm_to_ipc_perm(&in->sem_perm, &out.sem_perm); out.sem_otime = in->sem_otime; out.sem_ctime = in->sem_ctime; out.sem_nsems = in->sem_nsems; return copy_to_user(buf, &out, sizeof(out)); } default: return -EINVAL; } } |
e54d02b23 ipc: sem: Make se... |
1162 |
static time64_t get_semotime(struct sem_array *sma) |
d12e1e50e ipc/sem.c: replac... |
1163 1164 |
{ int i; |
e54d02b23 ipc: sem: Make se... |
1165 |
time64_t res; |
d12e1e50e ipc/sem.c: replac... |
1166 |
|
1a2339567 ipc/sem.c: remove... |
1167 |
res = sma->sems[0].sem_otime; |
d12e1e50e ipc/sem.c: replac... |
1168 |
for (i = 1; i < sma->sem_nsems; i++) { |
e54d02b23 ipc: sem: Make se... |
1169 |
time64_t to = sma->sems[i].sem_otime; |
d12e1e50e ipc/sem.c: replac... |
1170 1171 1172 1173 1174 1175 |
if (to > res) res = to; } return res; } |
45a4a64ab semctl(): separat... |
1176 1177 |
static int semctl_stat(struct ipc_namespace *ns, int semid, int cmd, struct semid64_ds *semid64) |
1da177e4c Linux-2.6.12-rc2 |
1178 |
{ |
1da177e4c Linux-2.6.12-rc2 |
1179 |
struct sem_array *sma; |
c2ab975c3 y2038: ipc: Repor... |
1180 |
time64_t semotime; |
45a4a64ab semctl(): separat... |
1181 |
int err; |
1da177e4c Linux-2.6.12-rc2 |
1182 |
|
45a4a64ab semctl(): separat... |
1183 |
memset(semid64, 0, sizeof(*semid64)); |
46c0a8ca3 ipc, kernel: clea... |
1184 |
|
45a4a64ab semctl(): separat... |
1185 |
rcu_read_lock(); |
a280d6dc7 ipc/sem: introduc... |
1186 |
if (cmd == SEM_STAT || cmd == SEM_STAT_ANY) { |
45a4a64ab semctl(): separat... |
1187 1188 1189 1190 1191 |
sma = sem_obtain_object(ns, semid); if (IS_ERR(sma)) { err = PTR_ERR(sma); goto out_unlock; } |
a280d6dc7 ipc/sem: introduc... |
1192 |
} else { /* IPC_STAT */ |
45a4a64ab semctl(): separat... |
1193 1194 1195 1196 |
sma = sem_obtain_object_check(ns, semid); if (IS_ERR(sma)) { err = PTR_ERR(sma); goto out_unlock; |
1da177e4c Linux-2.6.12-rc2 |
1197 |
} |
1da177e4c Linux-2.6.12-rc2 |
1198 |
} |
1da177e4c Linux-2.6.12-rc2 |
1199 |
|
a280d6dc7 ipc/sem: introduc... |
1200 1201 1202 1203 1204 1205 1206 1207 |
/* see comment for SHM_STAT_ANY */ if (cmd == SEM_STAT_ANY) audit_ipc_obj(&sma->sem_perm); else { err = -EACCES; if (ipcperms(ns, &sma->sem_perm, S_IRUGO)) goto out_unlock; } |
1da177e4c Linux-2.6.12-rc2 |
1208 |
|
aefad9593 sem/security: Pas... |
1209 |
err = security_sem_semctl(&sma->sem_perm, cmd); |
45a4a64ab semctl(): separat... |
1210 1211 |
if (err) goto out_unlock; |
1da177e4c Linux-2.6.12-rc2 |
1212 |
|
87ad4b0d8 ipc: fix ipc data... |
1213 1214 1215 1216 1217 1218 1219 |
ipc_lock_object(&sma->sem_perm); if (!ipc_valid_object(&sma->sem_perm)) { ipc_unlock_object(&sma->sem_perm); err = -EIDRM; goto out_unlock; } |
45a4a64ab semctl(): separat... |
1220 |
kernel_to_ipc64_perm(&sma->sem_perm, &semid64->sem_perm); |
c2ab975c3 y2038: ipc: Repor... |
1221 1222 |
semotime = get_semotime(sma); semid64->sem_otime = semotime; |
45a4a64ab semctl(): separat... |
1223 |
semid64->sem_ctime = sma->sem_ctime; |
c2ab975c3 y2038: ipc: Repor... |
1224 1225 1226 1227 |
#ifndef CONFIG_64BIT semid64->sem_otime_high = semotime >> 32; semid64->sem_ctime_high = sma->sem_ctime >> 32; #endif |
45a4a64ab semctl(): separat... |
1228 |
semid64->sem_nsems = sma->sem_nsems; |
87ad4b0d8 ipc: fix ipc data... |
1229 |
|
615c999cd ipc: compute kern... |
1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 |
if (cmd == IPC_STAT) { /* * As defined in SUS: * Return 0 on success */ err = 0; } else { /* * SEM_STAT and SEM_STAT_ANY (both Linux specific) * Return the full id, including the sequence number */ err = sma->sem_perm.id; } |
87ad4b0d8 ipc: fix ipc data... |
1243 |
ipc_unlock_object(&sma->sem_perm); |
1da177e4c Linux-2.6.12-rc2 |
1244 |
out_unlock: |
16df3674e ipc,sem: do not h... |
1245 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
1246 1247 |
return err; } |
45a4a64ab semctl(): separat... |
1248 1249 1250 1251 |
static int semctl_info(struct ipc_namespace *ns, int semid, int cmd, void __user *p) { struct seminfo seminfo; |
27c331a17 ipc/util.c: furth... |
1252 |
int max_idx; |
45a4a64ab semctl(): separat... |
1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 |
int err; err = security_sem_semctl(NULL, cmd); if (err) return err; memset(&seminfo, 0, sizeof(seminfo)); seminfo.semmni = ns->sc_semmni; seminfo.semmns = ns->sc_semmns; seminfo.semmsl = ns->sc_semmsl; seminfo.semopm = ns->sc_semopm; seminfo.semvmx = SEMVMX; seminfo.semmnu = SEMMNU; seminfo.semmap = SEMMAP; seminfo.semume = SEMUME; down_read(&sem_ids(ns).rwsem); if (cmd == SEM_INFO) { seminfo.semusz = sem_ids(ns).in_use; seminfo.semaem = ns->used_sems; } else { seminfo.semusz = SEMUSZ; seminfo.semaem = SEMAEM; } |
27c331a17 ipc/util.c: furth... |
1276 |
max_idx = ipc_get_maxidx(&sem_ids(ns)); |
45a4a64ab semctl(): separat... |
1277 1278 1279 |
up_read(&sem_ids(ns).rwsem); if (copy_to_user(p, &seminfo, sizeof(struct seminfo))) return -EFAULT; |
27c331a17 ipc/util.c: furth... |
1280 |
return (max_idx < 0) ? 0 : max_idx; |
45a4a64ab semctl(): separat... |
1281 |
} |
e1fd1f490 get rid of union ... |
1282 |
static int semctl_setval(struct ipc_namespace *ns, int semid, int semnum, |
45a4a64ab semctl(): separat... |
1283 |
int val) |
e1fd1f490 get rid of union ... |
1284 1285 1286 |
{ struct sem_undo *un; struct sem_array *sma; |
239521f31 ipc: whitespace c... |
1287 |
struct sem *curr; |
45a4a64ab semctl(): separat... |
1288 |
int err; |
9ae949fa3 ipc/sem: rework t... |
1289 |
DEFINE_WAKE_Q(wake_q); |
6062a8dc0 ipc,sem: fine gra... |
1290 1291 |
if (val > SEMVMX || val < 0) return -ERANGE; |
e1fd1f490 get rid of union ... |
1292 |
|
6062a8dc0 ipc,sem: fine gra... |
1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 |
rcu_read_lock(); sma = sem_obtain_object_check(ns, semid); if (IS_ERR(sma)) { rcu_read_unlock(); return PTR_ERR(sma); } if (semnum < 0 || semnum >= sma->sem_nsems) { rcu_read_unlock(); return -EINVAL; } if (ipcperms(ns, &sma->sem_perm, S_IWUGO)) { rcu_read_unlock(); return -EACCES; } |
e1fd1f490 get rid of union ... |
1310 |
|
aefad9593 sem/security: Pas... |
1311 |
err = security_sem_semctl(&sma->sem_perm, SETVAL); |
6062a8dc0 ipc,sem: fine gra... |
1312 1313 1314 1315 |
if (err) { rcu_read_unlock(); return -EACCES; } |
e1fd1f490 get rid of union ... |
1316 |
|
6062a8dc0 ipc,sem: fine gra... |
1317 |
sem_lock(sma, NULL, -1); |
e1fd1f490 get rid of union ... |
1318 |
|
0f3d2b013 ipc: introduce ip... |
1319 |
if (!ipc_valid_object(&sma->sem_perm)) { |
6e224f945 ipc/sem.c: synchr... |
1320 1321 1322 1323 |
sem_unlock(sma, -1); rcu_read_unlock(); return -EIDRM; } |
ec67aaa46 sysvipc/sem: miti... |
1324 |
semnum = array_index_nospec(semnum, sma->sem_nsems); |
1a2339567 ipc/sem.c: remove... |
1325 |
curr = &sma->sems[semnum]; |
e1fd1f490 get rid of union ... |
1326 |
|
cf9d5d78d ipc: close open c... |
1327 |
ipc_assert_locked_object(&sma->sem_perm); |
e1fd1f490 get rid of union ... |
1328 1329 1330 1331 |
list_for_each_entry(un, &sma->list_id, list_id) un->semadj[semnum] = 0; curr->semval = val; |
51d6f2635 ipc/sem: Fix semc... |
1332 |
ipc_update_pid(&curr->sempid, task_tgid(current)); |
e54d02b23 ipc: sem: Make se... |
1333 |
sma->sem_ctime = ktime_get_real_seconds(); |
e1fd1f490 get rid of union ... |
1334 |
/* maybe some queued-up processes were waiting for this */ |
9ae949fa3 ipc/sem: rework t... |
1335 |
do_smart_update(sma, NULL, 0, 0, &wake_q); |
6062a8dc0 ipc,sem: fine gra... |
1336 |
sem_unlock(sma, -1); |
6d49dab8a ipc: move rcu_rea... |
1337 |
rcu_read_unlock(); |
9ae949fa3 ipc/sem: rework t... |
1338 |
wake_up_q(&wake_q); |
6062a8dc0 ipc,sem: fine gra... |
1339 |
return 0; |
e1fd1f490 get rid of union ... |
1340 |
} |
e38935341 [PATCH] IPC names... |
1341 |
static int semctl_main(struct ipc_namespace *ns, int semid, int semnum, |
e1fd1f490 get rid of union ... |
1342 |
int cmd, void __user *p) |
1da177e4c Linux-2.6.12-rc2 |
1343 1344 |
{ struct sem_array *sma; |
239521f31 ipc: whitespace c... |
1345 |
struct sem *curr; |
16df3674e ipc,sem: do not h... |
1346 |
int err, nsems; |
1da177e4c Linux-2.6.12-rc2 |
1347 |
ushort fast_sem_io[SEMMSL_FAST]; |
239521f31 ipc: whitespace c... |
1348 |
ushort *sem_io = fast_sem_io; |
9ae949fa3 ipc/sem: rework t... |
1349 |
DEFINE_WAKE_Q(wake_q); |
16df3674e ipc,sem: do not h... |
1350 1351 1352 1353 1354 |
rcu_read_lock(); sma = sem_obtain_object_check(ns, semid); if (IS_ERR(sma)) { rcu_read_unlock(); |
023a53557 ipc: integrate ip... |
1355 |
return PTR_ERR(sma); |
16df3674e ipc,sem: do not h... |
1356 |
} |
1da177e4c Linux-2.6.12-rc2 |
1357 1358 |
nsems = sma->sem_nsems; |
1da177e4c Linux-2.6.12-rc2 |
1359 |
err = -EACCES; |
c728b9c87 ipc: simplify sem... |
1360 1361 |
if (ipcperms(ns, &sma->sem_perm, cmd == SETALL ? S_IWUGO : S_IRUGO)) goto out_rcu_wakeup; |
1da177e4c Linux-2.6.12-rc2 |
1362 |
|
aefad9593 sem/security: Pas... |
1363 |
err = security_sem_semctl(&sma->sem_perm, cmd); |
c728b9c87 ipc: simplify sem... |
1364 1365 |
if (err) goto out_rcu_wakeup; |
1da177e4c Linux-2.6.12-rc2 |
1366 1367 1368 1369 1370 |
err = -EACCES; switch (cmd) { case GETALL: { |
e1fd1f490 get rid of union ... |
1371 |
ushort __user *array = p; |
1da177e4c Linux-2.6.12-rc2 |
1372 |
int i; |
ce857229e ipc: fix GETALL/I... |
1373 |
sem_lock(sma, NULL, -1); |
0f3d2b013 ipc: introduce ip... |
1374 |
if (!ipc_valid_object(&sma->sem_perm)) { |
6e224f945 ipc/sem.c: synchr... |
1375 1376 1377 |
err = -EIDRM; goto out_unlock; } |
239521f31 ipc: whitespace c... |
1378 |
if (nsems > SEMMSL_FAST) { |
dba4cdd39 ipc: merge ipc_rc... |
1379 |
if (!ipc_rcu_getref(&sma->sem_perm)) { |
ce857229e ipc: fix GETALL/I... |
1380 |
err = -EIDRM; |
6e224f945 ipc/sem.c: synchr... |
1381 |
goto out_unlock; |
ce857229e ipc: fix GETALL/I... |
1382 1383 |
} sem_unlock(sma, -1); |
6d49dab8a ipc: move rcu_rea... |
1384 |
rcu_read_unlock(); |
f8dbe8d29 ipc: drop non-RCU... |
1385 1386 |
sem_io = kvmalloc_array(nsems, sizeof(ushort), GFP_KERNEL); |
239521f31 ipc: whitespace c... |
1387 |
if (sem_io == NULL) { |
dba4cdd39 ipc: merge ipc_rc... |
1388 |
ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); |
1da177e4c Linux-2.6.12-rc2 |
1389 1390 |
return -ENOMEM; } |
4091fd942 ipc: move the rcu... |
1391 |
rcu_read_lock(); |
6ff379721 IPC/semaphores: c... |
1392 |
sem_lock_and_putref(sma); |
0f3d2b013 ipc: introduce ip... |
1393 |
if (!ipc_valid_object(&sma->sem_perm)) { |
1da177e4c Linux-2.6.12-rc2 |
1394 |
err = -EIDRM; |
6e224f945 ipc/sem.c: synchr... |
1395 |
goto out_unlock; |
1da177e4c Linux-2.6.12-rc2 |
1396 |
} |
ce857229e ipc: fix GETALL/I... |
1397 |
} |
1da177e4c Linux-2.6.12-rc2 |
1398 |
for (i = 0; i < sma->sem_nsems; i++) |
1a2339567 ipc/sem.c: remove... |
1399 |
sem_io[i] = sma->sems[i].semval; |
6062a8dc0 ipc,sem: fine gra... |
1400 |
sem_unlock(sma, -1); |
6d49dab8a ipc: move rcu_rea... |
1401 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
1402 |
err = 0; |
239521f31 ipc: whitespace c... |
1403 |
if (copy_to_user(array, sem_io, nsems*sizeof(ushort))) |
1da177e4c Linux-2.6.12-rc2 |
1404 1405 1406 1407 1408 1409 1410 |
err = -EFAULT; goto out_free; } case SETALL: { int i; struct sem_undo *un; |
dba4cdd39 ipc: merge ipc_rc... |
1411 |
if (!ipc_rcu_getref(&sma->sem_perm)) { |
6e224f945 ipc/sem.c: synchr... |
1412 1413 |
err = -EIDRM; goto out_rcu_wakeup; |
6062a8dc0 ipc,sem: fine gra... |
1414 |
} |
16df3674e ipc,sem: do not h... |
1415 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
1416 |
|
239521f31 ipc: whitespace c... |
1417 |
if (nsems > SEMMSL_FAST) { |
f8dbe8d29 ipc: drop non-RCU... |
1418 1419 |
sem_io = kvmalloc_array(nsems, sizeof(ushort), GFP_KERNEL); |
239521f31 ipc: whitespace c... |
1420 |
if (sem_io == NULL) { |
dba4cdd39 ipc: merge ipc_rc... |
1421 |
ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); |
1da177e4c Linux-2.6.12-rc2 |
1422 1423 1424 |
return -ENOMEM; } } |
239521f31 ipc: whitespace c... |
1425 |
if (copy_from_user(sem_io, p, nsems*sizeof(ushort))) { |
dba4cdd39 ipc: merge ipc_rc... |
1426 |
ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); |
1da177e4c Linux-2.6.12-rc2 |
1427 1428 1429 1430 1431 1432 |
err = -EFAULT; goto out_free; } for (i = 0; i < nsems; i++) { if (sem_io[i] > SEMVMX) { |
dba4cdd39 ipc: merge ipc_rc... |
1433 |
ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); |
1da177e4c Linux-2.6.12-rc2 |
1434 1435 1436 1437 |
err = -ERANGE; goto out_free; } } |
4091fd942 ipc: move the rcu... |
1438 |
rcu_read_lock(); |
6ff379721 IPC/semaphores: c... |
1439 |
sem_lock_and_putref(sma); |
0f3d2b013 ipc: introduce ip... |
1440 |
if (!ipc_valid_object(&sma->sem_perm)) { |
1da177e4c Linux-2.6.12-rc2 |
1441 |
err = -EIDRM; |
6e224f945 ipc/sem.c: synchr... |
1442 |
goto out_unlock; |
1da177e4c Linux-2.6.12-rc2 |
1443 |
} |
a5f4db877 ipc/sem: make sem... |
1444 |
for (i = 0; i < nsems; i++) { |
1a2339567 ipc/sem.c: remove... |
1445 |
sma->sems[i].semval = sem_io[i]; |
51d6f2635 ipc/sem: Fix semc... |
1446 |
ipc_update_pid(&sma->sems[i].sempid, task_tgid(current)); |
a5f4db877 ipc/sem: make sem... |
1447 |
} |
4daa28f6d ipc/sem.c: conver... |
1448 |
|
cf9d5d78d ipc: close open c... |
1449 |
ipc_assert_locked_object(&sma->sem_perm); |
4daa28f6d ipc/sem.c: conver... |
1450 |
list_for_each_entry(un, &sma->list_id, list_id) { |
1da177e4c Linux-2.6.12-rc2 |
1451 1452 |
for (i = 0; i < nsems; i++) un->semadj[i] = 0; |
4daa28f6d ipc/sem.c: conver... |
1453 |
} |
e54d02b23 ipc: sem: Make se... |
1454 |
sma->sem_ctime = ktime_get_real_seconds(); |
1da177e4c Linux-2.6.12-rc2 |
1455 |
/* maybe some queued-up processes were waiting for this */ |
9ae949fa3 ipc/sem: rework t... |
1456 |
do_smart_update(sma, NULL, 0, 0, &wake_q); |
1da177e4c Linux-2.6.12-rc2 |
1457 1458 1459 |
err = 0; goto out_unlock; } |
e1fd1f490 get rid of union ... |
1460 |
/* GETVAL, GETPID, GETNCTN, GETZCNT: fall-through */ |
1da177e4c Linux-2.6.12-rc2 |
1461 1462 |
} err = -EINVAL; |
c728b9c87 ipc: simplify sem... |
1463 1464 |
if (semnum < 0 || semnum >= nsems) goto out_rcu_wakeup; |
1da177e4c Linux-2.6.12-rc2 |
1465 |
|
6062a8dc0 ipc,sem: fine gra... |
1466 |
sem_lock(sma, NULL, -1); |
0f3d2b013 ipc: introduce ip... |
1467 |
if (!ipc_valid_object(&sma->sem_perm)) { |
6e224f945 ipc/sem.c: synchr... |
1468 1469 1470 |
err = -EIDRM; goto out_unlock; } |
ec67aaa46 sysvipc/sem: miti... |
1471 1472 |
semnum = array_index_nospec(semnum, nsems); |
1a2339567 ipc/sem.c: remove... |
1473 |
curr = &sma->sems[semnum]; |
1da177e4c Linux-2.6.12-rc2 |
1474 1475 1476 1477 1478 1479 |
switch (cmd) { case GETVAL: err = curr->semval; goto out_unlock; case GETPID: |
51d6f2635 ipc/sem: Fix semc... |
1480 |
err = pid_vnr(curr->sempid); |
1da177e4c Linux-2.6.12-rc2 |
1481 1482 |
goto out_unlock; case GETNCNT: |
2f2ed41dc ipc/sem.c: remove... |
1483 |
err = count_semcnt(sma, semnum, 0); |
1da177e4c Linux-2.6.12-rc2 |
1484 1485 |
goto out_unlock; case GETZCNT: |
2f2ed41dc ipc/sem.c: remove... |
1486 |
err = count_semcnt(sma, semnum, 1); |
1da177e4c Linux-2.6.12-rc2 |
1487 |
goto out_unlock; |
1da177e4c Linux-2.6.12-rc2 |
1488 |
} |
16df3674e ipc,sem: do not h... |
1489 |
|
1da177e4c Linux-2.6.12-rc2 |
1490 |
out_unlock: |
6062a8dc0 ipc,sem: fine gra... |
1491 |
sem_unlock(sma, -1); |
c728b9c87 ipc: simplify sem... |
1492 |
out_rcu_wakeup: |
6d49dab8a ipc: move rcu_rea... |
1493 |
rcu_read_unlock(); |
9ae949fa3 ipc/sem: rework t... |
1494 |
wake_up_q(&wake_q); |
1da177e4c Linux-2.6.12-rc2 |
1495 |
out_free: |
239521f31 ipc: whitespace c... |
1496 |
if (sem_io != fast_sem_io) |
f8dbe8d29 ipc: drop non-RCU... |
1497 |
kvfree(sem_io); |
1da177e4c Linux-2.6.12-rc2 |
1498 1499 |
return err; } |
016d7132f IPC: get rid of t... |
1500 1501 |
static inline unsigned long copy_semid_from_user(struct semid64_ds *out, void __user *buf, int version) |
1da177e4c Linux-2.6.12-rc2 |
1502 |
{ |
239521f31 ipc: whitespace c... |
1503 |
switch (version) { |
1da177e4c Linux-2.6.12-rc2 |
1504 |
case IPC_64: |
016d7132f IPC: get rid of t... |
1505 |
if (copy_from_user(out, buf, sizeof(*out))) |
1da177e4c Linux-2.6.12-rc2 |
1506 |
return -EFAULT; |
1da177e4c Linux-2.6.12-rc2 |
1507 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
1508 1509 1510 |
case IPC_OLD: { struct semid_ds tbuf_old; |
239521f31 ipc: whitespace c... |
1511 |
if (copy_from_user(&tbuf_old, buf, sizeof(tbuf_old))) |
1da177e4c Linux-2.6.12-rc2 |
1512 |
return -EFAULT; |
016d7132f IPC: get rid of t... |
1513 1514 1515 |
out->sem_perm.uid = tbuf_old.sem_perm.uid; out->sem_perm.gid = tbuf_old.sem_perm.gid; out->sem_perm.mode = tbuf_old.sem_perm.mode; |
1da177e4c Linux-2.6.12-rc2 |
1516 1517 1518 1519 1520 1521 1522 |
return 0; } default: return -EINVAL; } } |
522bb2a2b IPC/semaphores: m... |
1523 |
/* |
d9a605e40 ipc: rename ids->... |
1524 |
* This function handles some semctl commands which require the rwsem |
522bb2a2b IPC/semaphores: m... |
1525 |
* to be held in write mode. |
d9a605e40 ipc: rename ids->... |
1526 |
* NOTE: no locks must be held, the rwsem is taken inside this function. |
522bb2a2b IPC/semaphores: m... |
1527 |
*/ |
21a4826a7 IPC/semaphores: r... |
1528 |
static int semctl_down(struct ipc_namespace *ns, int semid, |
45a4a64ab semctl(): separat... |
1529 |
int cmd, struct semid64_ds *semid64) |
1da177e4c Linux-2.6.12-rc2 |
1530 1531 1532 |
{ struct sem_array *sma; int err; |
1da177e4c Linux-2.6.12-rc2 |
1533 |
struct kern_ipc_perm *ipcp; |
d9a605e40 ipc: rename ids->... |
1534 |
down_write(&sem_ids(ns).rwsem); |
7b4cc5d84 ipc: move locking... |
1535 |
rcu_read_lock(); |
4241c1a30 ipc: rename ipcct... |
1536 |
ipcp = ipcctl_obtain_check(ns, &sem_ids(ns), semid, cmd, |
45a4a64ab semctl(): separat... |
1537 |
&semid64->sem_perm, 0); |
7b4cc5d84 ipc: move locking... |
1538 1539 |
if (IS_ERR(ipcp)) { err = PTR_ERR(ipcp); |
7b4cc5d84 ipc: move locking... |
1540 1541 |
goto out_unlock1; } |
073115d6b [PATCH] Rework of... |
1542 |
|
a5f75e7f2 IPC: consolidate ... |
1543 |
sma = container_of(ipcp, struct sem_array, sem_perm); |
1da177e4c Linux-2.6.12-rc2 |
1544 |
|
aefad9593 sem/security: Pas... |
1545 |
err = security_sem_semctl(&sma->sem_perm, cmd); |
7b4cc5d84 ipc: move locking... |
1546 1547 |
if (err) goto out_unlock1; |
1da177e4c Linux-2.6.12-rc2 |
1548 |
|
7b4cc5d84 ipc: move locking... |
1549 |
switch (cmd) { |
1da177e4c Linux-2.6.12-rc2 |
1550 |
case IPC_RMID: |
6062a8dc0 ipc,sem: fine gra... |
1551 |
sem_lock(sma, NULL, -1); |
7b4cc5d84 ipc: move locking... |
1552 |
/* freeary unlocks the ipc object and rcu */ |
01b8b07a5 IPC: consolidate ... |
1553 |
freeary(ns, ipcp); |
522bb2a2b IPC/semaphores: m... |
1554 |
goto out_up; |
1da177e4c Linux-2.6.12-rc2 |
1555 |
case IPC_SET: |
6062a8dc0 ipc,sem: fine gra... |
1556 |
sem_lock(sma, NULL, -1); |
45a4a64ab semctl(): separat... |
1557 |
err = ipc_update_perm(&semid64->sem_perm, ipcp); |
1efdb69b0 userns: Convert i... |
1558 |
if (err) |
7b4cc5d84 ipc: move locking... |
1559 |
goto out_unlock0; |
e54d02b23 ipc: sem: Make se... |
1560 |
sma->sem_ctime = ktime_get_real_seconds(); |
1da177e4c Linux-2.6.12-rc2 |
1561 1562 |
break; default: |
1da177e4c Linux-2.6.12-rc2 |
1563 |
err = -EINVAL; |
7b4cc5d84 ipc: move locking... |
1564 |
goto out_unlock1; |
1da177e4c Linux-2.6.12-rc2 |
1565 |
} |
1da177e4c Linux-2.6.12-rc2 |
1566 |
|
7b4cc5d84 ipc: move locking... |
1567 |
out_unlock0: |
6062a8dc0 ipc,sem: fine gra... |
1568 |
sem_unlock(sma, -1); |
7b4cc5d84 ipc: move locking... |
1569 |
out_unlock1: |
6d49dab8a ipc: move rcu_rea... |
1570 |
rcu_read_unlock(); |
522bb2a2b IPC/semaphores: m... |
1571 |
out_up: |
d9a605e40 ipc: rename ids->... |
1572 |
up_write(&sem_ids(ns).rwsem); |
1da177e4c Linux-2.6.12-rc2 |
1573 1574 |
return err; } |
d969c6fa7 ipc: add semctl s... |
1575 |
long ksys_semctl(int semid, int semnum, int cmd, unsigned long arg) |
1da177e4c Linux-2.6.12-rc2 |
1576 |
{ |
1da177e4c Linux-2.6.12-rc2 |
1577 |
int version; |
e38935341 [PATCH] IPC names... |
1578 |
struct ipc_namespace *ns; |
e1fd1f490 get rid of union ... |
1579 |
void __user *p = (void __user *)arg; |
45a4a64ab semctl(): separat... |
1580 1581 |
struct semid64_ds semid64; int err; |
1da177e4c Linux-2.6.12-rc2 |
1582 1583 1584 1585 1586 |
if (semid < 0) return -EINVAL; version = ipc_parse_version(&cmd); |
e38935341 [PATCH] IPC names... |
1587 |
ns = current->nsproxy->ipc_ns; |
1da177e4c Linux-2.6.12-rc2 |
1588 |
|
239521f31 ipc: whitespace c... |
1589 |
switch (cmd) { |
1da177e4c Linux-2.6.12-rc2 |
1590 1591 |
case IPC_INFO: case SEM_INFO: |
45a4a64ab semctl(): separat... |
1592 |
return semctl_info(ns, semid, cmd, p); |
4b9fcb0ec IPC/semaphores: c... |
1593 |
case IPC_STAT: |
1da177e4c Linux-2.6.12-rc2 |
1594 |
case SEM_STAT: |
a280d6dc7 ipc/sem: introduc... |
1595 |
case SEM_STAT_ANY: |
45a4a64ab semctl(): separat... |
1596 1597 1598 1599 1600 1601 |
err = semctl_stat(ns, semid, cmd, &semid64); if (err < 0) return err; if (copy_semid_to_user(p, &semid64, version)) err = -EFAULT; return err; |
1da177e4c Linux-2.6.12-rc2 |
1602 1603 1604 1605 1606 |
case GETALL: case GETVAL: case GETPID: case GETNCNT: case GETZCNT: |
1da177e4c Linux-2.6.12-rc2 |
1607 |
case SETALL: |
e1fd1f490 get rid of union ... |
1608 |
return semctl_main(ns, semid, semnum, cmd, p); |
45a4a64ab semctl(): separat... |
1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 |
case SETVAL: { int val; #if defined(CONFIG_64BIT) && defined(__BIG_ENDIAN) /* big-endian 64bit */ val = arg >> 32; #else /* 32bit or little-endian 64bit */ val = arg; #endif return semctl_setval(ns, semid, semnum, val); } |
1da177e4c Linux-2.6.12-rc2 |
1620 |
case IPC_SET: |
45a4a64ab semctl(): separat... |
1621 1622 1623 1624 |
if (copy_semid_from_user(&semid64, p, version)) return -EFAULT; case IPC_RMID: return semctl_down(ns, semid, cmd, &semid64); |
1da177e4c Linux-2.6.12-rc2 |
1625 1626 1627 1628 |
default: return -EINVAL; } } |
d969c6fa7 ipc: add semctl s... |
1629 1630 1631 1632 |
SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, unsigned long, arg) { return ksys_semctl(semid, semnum, cmd, arg); } |
c0ebccb6f semctl(): move co... |
1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 |
#ifdef CONFIG_COMPAT struct compat_semid_ds { struct compat_ipc_perm sem_perm; compat_time_t sem_otime; compat_time_t sem_ctime; compat_uptr_t sem_base; compat_uptr_t sem_pending; compat_uptr_t sem_pending_last; compat_uptr_t undo; unsigned short sem_nsems; }; static int copy_compat_semid_from_user(struct semid64_ds *out, void __user *buf, int version) { memset(out, 0, sizeof(*out)); if (version == IPC_64) { |
6aa211e8c fix address space... |
1651 |
struct compat_semid64_ds __user *p = buf; |
c0ebccb6f semctl(): move co... |
1652 1653 |
return get_compat_ipc64_perm(&out->sem_perm, &p->sem_perm); } else { |
6aa211e8c fix address space... |
1654 |
struct compat_semid_ds __user *p = buf; |
c0ebccb6f semctl(): move co... |
1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 |
return get_compat_ipc_perm(&out->sem_perm, &p->sem_perm); } } static int copy_compat_semid_to_user(void __user *buf, struct semid64_ds *in, int version) { if (version == IPC_64) { struct compat_semid64_ds v; memset(&v, 0, sizeof(v)); to_compat_ipc64_perm(&v.sem_perm, &in->sem_perm); |
c2ab975c3 y2038: ipc: Repor... |
1666 1667 1668 1669 |
v.sem_otime = lower_32_bits(in->sem_otime); v.sem_otime_high = upper_32_bits(in->sem_otime); v.sem_ctime = lower_32_bits(in->sem_ctime); v.sem_ctime_high = upper_32_bits(in->sem_ctime); |
c0ebccb6f semctl(): move co... |
1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 |
v.sem_nsems = in->sem_nsems; return copy_to_user(buf, &v, sizeof(v)); } else { struct compat_semid_ds v; memset(&v, 0, sizeof(v)); to_compat_ipc_perm(&v.sem_perm, &in->sem_perm); v.sem_otime = in->sem_otime; v.sem_ctime = in->sem_ctime; v.sem_nsems = in->sem_nsems; return copy_to_user(buf, &v, sizeof(v)); } } |
d969c6fa7 ipc: add semctl s... |
1682 |
long compat_ksys_semctl(int semid, int semnum, int cmd, int arg) |
c0ebccb6f semctl(): move co... |
1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 |
{ void __user *p = compat_ptr(arg); struct ipc_namespace *ns; struct semid64_ds semid64; int version = compat_ipc_parse_version(&cmd); int err; ns = current->nsproxy->ipc_ns; if (semid < 0) return -EINVAL; switch (cmd & (~IPC_64)) { case IPC_INFO: case SEM_INFO: return semctl_info(ns, semid, cmd, p); case IPC_STAT: case SEM_STAT: |
a280d6dc7 ipc/sem: introduc... |
1701 |
case SEM_STAT_ANY: |
c0ebccb6f semctl(): move co... |
1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 |
err = semctl_stat(ns, semid, cmd, &semid64); if (err < 0) return err; if (copy_compat_semid_to_user(p, &semid64, version)) err = -EFAULT; return err; case GETVAL: case GETPID: case GETNCNT: case GETZCNT: case GETALL: case SETALL: return semctl_main(ns, semid, semnum, cmd, p); |
e1fd1f490 get rid of union ... |
1715 1716 |
case SETVAL: return semctl_setval(ns, semid, semnum, arg); |
1da177e4c Linux-2.6.12-rc2 |
1717 |
case IPC_SET: |
c0ebccb6f semctl(): move co... |
1718 1719 1720 1721 1722 |
if (copy_compat_semid_from_user(&semid64, p, version)) return -EFAULT; /* fallthru */ case IPC_RMID: return semctl_down(ns, semid, cmd, &semid64); |
1da177e4c Linux-2.6.12-rc2 |
1723 1724 1725 1726 |
default: return -EINVAL; } } |
d969c6fa7 ipc: add semctl s... |
1727 1728 1729 1730 1731 |
COMPAT_SYSCALL_DEFINE4(semctl, int, semid, int, semnum, int, cmd, int, arg) { return compat_ksys_semctl(semid, semnum, cmd, arg); } |
c0ebccb6f semctl(): move co... |
1732 |
#endif |
1da177e4c Linux-2.6.12-rc2 |
1733 |
|
1da177e4c Linux-2.6.12-rc2 |
1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 |
/* If the task doesn't already have a undo_list, then allocate one * here. We guarantee there is only one thread using this undo list, * and current is THE ONE * * If this allocation and assignment succeeds, but later * portions of this code fail, there is no need to free the sem_undo_list. * Just let it stay associated with the task, and it'll be freed later * at exit time. * * This can block, so callers must hold no locks. */ static inline int get_undo_list(struct sem_undo_list **undo_listp) { struct sem_undo_list *undo_list; |
1da177e4c Linux-2.6.12-rc2 |
1748 1749 1750 |
undo_list = current->sysvsem.undo_list; if (!undo_list) { |
2453a3062 [PATCH] ipc: repl... |
1751 |
undo_list = kzalloc(sizeof(*undo_list), GFP_KERNEL); |
1da177e4c Linux-2.6.12-rc2 |
1752 1753 |
if (undo_list == NULL) return -ENOMEM; |
00a5dfdb9 [PATCH] Fix semun... |
1754 |
spin_lock_init(&undo_list->lock); |
f74370b86 ipc: convert sem_... |
1755 |
refcount_set(&undo_list->refcnt, 1); |
4daa28f6d ipc/sem.c: conver... |
1756 |
INIT_LIST_HEAD(&undo_list->list_proc); |
1da177e4c Linux-2.6.12-rc2 |
1757 1758 1759 1760 1761 |
current->sysvsem.undo_list = undo_list; } *undo_listp = undo_list; return 0; } |
bf17bb717 ipc/sem.c: sem op... |
1762 |
static struct sem_undo *__lookup_undo(struct sem_undo_list *ulp, int semid) |
1da177e4c Linux-2.6.12-rc2 |
1763 |
{ |
bf17bb717 ipc/sem.c: sem op... |
1764 |
struct sem_undo *un; |
4daa28f6d ipc/sem.c: conver... |
1765 |
|
bf17bb717 ipc/sem.c: sem op... |
1766 1767 1768 |
list_for_each_entry_rcu(un, &ulp->list_proc, list_proc) { if (un->semid == semid) return un; |
1da177e4c Linux-2.6.12-rc2 |
1769 |
} |
4daa28f6d ipc/sem.c: conver... |
1770 |
return NULL; |
1da177e4c Linux-2.6.12-rc2 |
1771 |
} |
bf17bb717 ipc/sem.c: sem op... |
1772 1773 1774 |
static struct sem_undo *lookup_undo(struct sem_undo_list *ulp, int semid) { struct sem_undo *un; |
239521f31 ipc: whitespace c... |
1775 |
assert_spin_locked(&ulp->lock); |
bf17bb717 ipc/sem.c: sem op... |
1776 1777 1778 1779 1780 1781 1782 1783 |
un = __lookup_undo(ulp, semid); if (un) { list_del_rcu(&un->list_proc); list_add_rcu(&un->list_proc, &ulp->list_proc); } return un; } |
4daa28f6d ipc/sem.c: conver... |
1784 |
/** |
8001c8581 ipc: standardize ... |
1785 |
* find_alloc_undo - lookup (and if not present create) undo array |
4daa28f6d ipc/sem.c: conver... |
1786 1787 1788 1789 1790 1791 |
* @ns: namespace * @semid: semaphore array id * * The function looks up (and if not present creates) the undo structure. * The size of the undo structure depends on the size of the semaphore * array, thus the alloc path is not that straightforward. |
380af1b33 ipc/sem.c: rewrit... |
1792 1793 |
* Lifetime-rules: sem_undo is rcu-protected, on success, the function * performs a rcu_read_lock(). |
4daa28f6d ipc/sem.c: conver... |
1794 1795 |
*/ static struct sem_undo *find_alloc_undo(struct ipc_namespace *ns, int semid) |
1da177e4c Linux-2.6.12-rc2 |
1796 1797 1798 1799 |
{ struct sem_array *sma; struct sem_undo_list *ulp; struct sem_undo *un, *new; |
6062a8dc0 ipc,sem: fine gra... |
1800 |
int nsems, error; |
1da177e4c Linux-2.6.12-rc2 |
1801 1802 1803 1804 |
error = get_undo_list(&ulp); if (error) return ERR_PTR(error); |
380af1b33 ipc/sem.c: rewrit... |
1805 |
rcu_read_lock(); |
c530c6ac7 IPC: cleanup some... |
1806 |
spin_lock(&ulp->lock); |
1da177e4c Linux-2.6.12-rc2 |
1807 |
un = lookup_undo(ulp, semid); |
c530c6ac7 IPC: cleanup some... |
1808 |
spin_unlock(&ulp->lock); |
239521f31 ipc: whitespace c... |
1809 |
if (likely(un != NULL)) |
1da177e4c Linux-2.6.12-rc2 |
1810 1811 1812 |
goto out; /* no undo structure around - allocate one. */ |
4daa28f6d ipc/sem.c: conver... |
1813 |
/* step 1: figure out the size of the semaphore array */ |
16df3674e ipc,sem: do not h... |
1814 1815 1816 |
sma = sem_obtain_object_check(ns, semid); if (IS_ERR(sma)) { rcu_read_unlock(); |
4de85cd6d ipc/sem.c: use ER... |
1817 |
return ERR_CAST(sma); |
16df3674e ipc,sem: do not h... |
1818 |
} |
023a53557 ipc: integrate ip... |
1819 |
|
1da177e4c Linux-2.6.12-rc2 |
1820 |
nsems = sma->sem_nsems; |
dba4cdd39 ipc: merge ipc_rc... |
1821 |
if (!ipc_rcu_getref(&sma->sem_perm)) { |
6062a8dc0 ipc,sem: fine gra... |
1822 1823 1824 1825 |
rcu_read_unlock(); un = ERR_PTR(-EIDRM); goto out; } |
16df3674e ipc,sem: do not h... |
1826 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
1827 |
|
4daa28f6d ipc/sem.c: conver... |
1828 |
/* step 2: allocate new undo structure */ |
4668edc33 [PATCH] kernel co... |
1829 |
new = kzalloc(sizeof(struct sem_undo) + sizeof(short)*nsems, GFP_KERNEL); |
1da177e4c Linux-2.6.12-rc2 |
1830 |
if (!new) { |
dba4cdd39 ipc: merge ipc_rc... |
1831 |
ipc_rcu_putref(&sma->sem_perm, sem_rcu_free); |
1da177e4c Linux-2.6.12-rc2 |
1832 1833 |
return ERR_PTR(-ENOMEM); } |
1da177e4c Linux-2.6.12-rc2 |
1834 |
|
380af1b33 ipc/sem.c: rewrit... |
1835 |
/* step 3: Acquire the lock on semaphore array */ |
4091fd942 ipc: move the rcu... |
1836 |
rcu_read_lock(); |
6ff379721 IPC/semaphores: c... |
1837 |
sem_lock_and_putref(sma); |
0f3d2b013 ipc: introduce ip... |
1838 |
if (!ipc_valid_object(&sma->sem_perm)) { |
6062a8dc0 ipc,sem: fine gra... |
1839 |
sem_unlock(sma, -1); |
6d49dab8a ipc: move rcu_rea... |
1840 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
1841 1842 1843 1844 |
kfree(new); un = ERR_PTR(-EIDRM); goto out; } |
380af1b33 ipc/sem.c: rewrit... |
1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 |
spin_lock(&ulp->lock); /* * step 4: check for races: did someone else allocate the undo struct? */ un = lookup_undo(ulp, semid); if (un) { kfree(new); goto success; } |
4daa28f6d ipc/sem.c: conver... |
1855 1856 |
/* step 5: initialize & link new undo structure */ new->semadj = (short *) &new[1]; |
380af1b33 ipc/sem.c: rewrit... |
1857 |
new->ulp = ulp; |
4daa28f6d ipc/sem.c: conver... |
1858 1859 |
new->semid = semid; assert_spin_locked(&ulp->lock); |
380af1b33 ipc/sem.c: rewrit... |
1860 |
list_add_rcu(&new->list_proc, &ulp->list_proc); |
cf9d5d78d ipc: close open c... |
1861 |
ipc_assert_locked_object(&sma->sem_perm); |
4daa28f6d ipc/sem.c: conver... |
1862 |
list_add(&new->list_id, &sma->list_id); |
380af1b33 ipc/sem.c: rewrit... |
1863 |
un = new; |
4daa28f6d ipc/sem.c: conver... |
1864 |
|
380af1b33 ipc/sem.c: rewrit... |
1865 |
success: |
c530c6ac7 IPC: cleanup some... |
1866 |
spin_unlock(&ulp->lock); |
6062a8dc0 ipc,sem: fine gra... |
1867 |
sem_unlock(sma, -1); |
1da177e4c Linux-2.6.12-rc2 |
1868 1869 1870 |
out: return un; } |
44ee45467 semtimedop(): mov... |
1871 |
static long do_semtimedop(int semid, struct sembuf __user *tsops, |
3ef56dc26 ipc: Make sys_sem... |
1872 |
unsigned nsops, const struct timespec64 *timeout) |
1da177e4c Linux-2.6.12-rc2 |
1873 1874 1875 1876 |
{ int error = -EINVAL; struct sem_array *sma; struct sembuf fast_sops[SEMOPM_FAST]; |
239521f31 ipc: whitespace c... |
1877 |
struct sembuf *sops = fast_sops, *sop; |
1da177e4c Linux-2.6.12-rc2 |
1878 |
struct sem_undo *un; |
4ce33ec2e ipc/sem: optimize... |
1879 1880 |
int max, locknum; bool undos = false, alter = false, dupsop = false; |
1da177e4c Linux-2.6.12-rc2 |
1881 |
struct sem_queue queue; |
4ce33ec2e ipc/sem: optimize... |
1882 |
unsigned long dup = 0, jiffies_left = 0; |
e38935341 [PATCH] IPC names... |
1883 1884 1885 |
struct ipc_namespace *ns; ns = current->nsproxy->ipc_ns; |
1da177e4c Linux-2.6.12-rc2 |
1886 1887 1888 |
if (nsops < 1 || semid < 0) return -EINVAL; |
e38935341 [PATCH] IPC names... |
1889 |
if (nsops > ns->sc_semopm) |
1da177e4c Linux-2.6.12-rc2 |
1890 |
return -E2BIG; |
239521f31 ipc: whitespace c... |
1891 |
if (nsops > SEMOPM_FAST) { |
344476e16 treewide: kvmallo... |
1892 |
sops = kvmalloc_array(nsops, sizeof(*sops), GFP_KERNEL); |
239521f31 ipc: whitespace c... |
1893 |
if (sops == NULL) |
1da177e4c Linux-2.6.12-rc2 |
1894 1895 |
return -ENOMEM; } |
4ce33ec2e ipc/sem: optimize... |
1896 |
|
239521f31 ipc: whitespace c... |
1897 1898 |
if (copy_from_user(sops, tsops, nsops * sizeof(*tsops))) { error = -EFAULT; |
1da177e4c Linux-2.6.12-rc2 |
1899 1900 |
goto out_free; } |
4ce33ec2e ipc/sem: optimize... |
1901 |
|
1da177e4c Linux-2.6.12-rc2 |
1902 |
if (timeout) { |
44ee45467 semtimedop(): mov... |
1903 1904 |
if (timeout->tv_sec < 0 || timeout->tv_nsec < 0 || timeout->tv_nsec >= 1000000000L) { |
1da177e4c Linux-2.6.12-rc2 |
1905 1906 1907 |
error = -EINVAL; goto out_free; } |
3ef56dc26 ipc: Make sys_sem... |
1908 |
jiffies_left = timespec64_to_jiffies(timeout); |
1da177e4c Linux-2.6.12-rc2 |
1909 |
} |
4ce33ec2e ipc/sem: optimize... |
1910 |
|
1da177e4c Linux-2.6.12-rc2 |
1911 1912 |
max = 0; for (sop = sops; sop < sops + nsops; sop++) { |
4ce33ec2e ipc/sem: optimize... |
1913 |
unsigned long mask = 1ULL << ((sop->sem_num) % BITS_PER_LONG); |
1da177e4c Linux-2.6.12-rc2 |
1914 1915 1916 |
if (sop->sem_num >= max) max = sop->sem_num; if (sop->sem_flg & SEM_UNDO) |
4ce33ec2e ipc/sem: optimize... |
1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 |
undos = true; if (dup & mask) { /* * There was a previous alter access that appears * to have accessed the same semaphore, thus use * the dupsop logic. "appears", because the detection * can only check % BITS_PER_LONG. */ dupsop = true; } if (sop->sem_op != 0) { alter = true; dup |= mask; } |
1da177e4c Linux-2.6.12-rc2 |
1931 |
} |
1da177e4c Linux-2.6.12-rc2 |
1932 |
|
1da177e4c Linux-2.6.12-rc2 |
1933 |
if (undos) { |
6062a8dc0 ipc,sem: fine gra... |
1934 |
/* On success, find_alloc_undo takes the rcu_read_lock */ |
4daa28f6d ipc/sem.c: conver... |
1935 |
un = find_alloc_undo(ns, semid); |
1da177e4c Linux-2.6.12-rc2 |
1936 1937 1938 1939 |
if (IS_ERR(un)) { error = PTR_ERR(un); goto out_free; } |
6062a8dc0 ipc,sem: fine gra... |
1940 |
} else { |
1da177e4c Linux-2.6.12-rc2 |
1941 |
un = NULL; |
6062a8dc0 ipc,sem: fine gra... |
1942 1943 |
rcu_read_lock(); } |
1da177e4c Linux-2.6.12-rc2 |
1944 |
|
16df3674e ipc,sem: do not h... |
1945 |
sma = sem_obtain_object_check(ns, semid); |
023a53557 ipc: integrate ip... |
1946 |
if (IS_ERR(sma)) { |
6062a8dc0 ipc,sem: fine gra... |
1947 |
rcu_read_unlock(); |
023a53557 ipc: integrate ip... |
1948 |
error = PTR_ERR(sma); |
1da177e4c Linux-2.6.12-rc2 |
1949 |
goto out_free; |
023a53557 ipc: integrate ip... |
1950 |
} |
16df3674e ipc,sem: do not h... |
1951 |
error = -EFBIG; |
248e7357c ipc/sem: do not c... |
1952 1953 1954 1955 |
if (max >= sma->sem_nsems) { rcu_read_unlock(); goto out_free; } |
16df3674e ipc,sem: do not h... |
1956 1957 |
error = -EACCES; |
248e7357c ipc/sem: do not c... |
1958 1959 1960 1961 |
if (ipcperms(ns, &sma->sem_perm, alter ? S_IWUGO : S_IRUGO)) { rcu_read_unlock(); goto out_free; } |
16df3674e ipc,sem: do not h... |
1962 |
|
aefad9593 sem/security: Pas... |
1963 |
error = security_sem_semop(&sma->sem_perm, sops, nsops, alter); |
248e7357c ipc/sem: do not c... |
1964 1965 1966 1967 |
if (error) { rcu_read_unlock(); goto out_free; } |
16df3674e ipc,sem: do not h... |
1968 |
|
6e224f945 ipc/sem.c: synchr... |
1969 1970 |
error = -EIDRM; locknum = sem_lock(sma, sops, nsops); |
0f3d2b013 ipc: introduce ip... |
1971 1972 1973 1974 1975 1976 1977 1978 1979 |
/* * We eventually might perform the following check in a lockless * fashion, considering ipc_valid_object() locking constraints. * If nsops == 1 and there is no contention for sem_perm.lock, then * only a per-semaphore lock is held and it's OK to proceed with the * check below. More details on the fine grained locking scheme * entangled here and why it's RMID race safe on comments at sem_lock() */ if (!ipc_valid_object(&sma->sem_perm)) |
6e224f945 ipc/sem.c: synchr... |
1980 |
goto out_unlock_free; |
1da177e4c Linux-2.6.12-rc2 |
1981 |
/* |
4daa28f6d ipc/sem.c: conver... |
1982 |
* semid identifiers are not unique - find_alloc_undo may have |
1da177e4c Linux-2.6.12-rc2 |
1983 |
* allocated an undo structure, it was invalidated by an RMID |
4daa28f6d ipc/sem.c: conver... |
1984 |
* and now a new array with received the same id. Check and fail. |
25985edce Fix common misspe... |
1985 |
* This case can be detected checking un->semid. The existence of |
380af1b33 ipc/sem.c: rewrit... |
1986 |
* "un" itself is guaranteed by rcu. |
1da177e4c Linux-2.6.12-rc2 |
1987 |
*/ |
6062a8dc0 ipc,sem: fine gra... |
1988 1989 |
if (un && un->semid == -1) goto out_unlock_free; |
4daa28f6d ipc/sem.c: conver... |
1990 |
|
d198cd6d6 ipc/sem.c: change... |
1991 1992 1993 |
queue.sops = sops; queue.nsops = nsops; queue.undo = un; |
51d6f2635 ipc/sem: Fix semc... |
1994 |
queue.pid = task_tgid(current); |
d198cd6d6 ipc/sem.c: change... |
1995 |
queue.alter = alter; |
4ce33ec2e ipc/sem: optimize... |
1996 |
queue.dupsop = dupsop; |
d198cd6d6 ipc/sem.c: change... |
1997 1998 |
error = perform_atomic_semop(sma, &queue); |
9ae949fa3 ipc/sem: rework t... |
1999 2000 2001 2002 2003 |
if (error == 0) { /* non-blocking succesfull path */ DEFINE_WAKE_Q(wake_q); /* * If the operation was successful, then do |
0e8c66569 ipc/sem.c: update... |
2004 2005 2006 |
* the required updates. */ if (alter) |
9ae949fa3 ipc/sem: rework t... |
2007 |
do_smart_update(sma, sops, nsops, 1, &wake_q); |
0e8c66569 ipc/sem.c: update... |
2008 2009 |
else set_semotime(sma, sops); |
9ae949fa3 ipc/sem: rework t... |
2010 2011 2012 2013 2014 2015 |
sem_unlock(sma, locknum); rcu_read_unlock(); wake_up_q(&wake_q); goto out_free; |
1da177e4c Linux-2.6.12-rc2 |
2016 |
} |
9ae949fa3 ipc/sem: rework t... |
2017 |
if (error < 0) /* non-blocking error path */ |
0e8c66569 ipc/sem.c: update... |
2018 |
goto out_unlock_free; |
1da177e4c Linux-2.6.12-rc2 |
2019 |
|
9ae949fa3 ipc/sem: rework t... |
2020 2021 |
/* * We need to sleep on this operation, so we put the current |
1da177e4c Linux-2.6.12-rc2 |
2022 2023 |
* task into the pending queue and go to sleep. */ |
b97e820ff ipc/sem.c: add a ... |
2024 2025 |
if (nsops == 1) { struct sem *curr; |
ec67aaa46 sysvipc/sem: miti... |
2026 2027 |
int idx = array_index_nospec(sops->sem_num, sma->sem_nsems); curr = &sma->sems[idx]; |
b97e820ff ipc/sem.c: add a ... |
2028 |
|
f269f40ad ipc/sem.c: always... |
2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 |
if (alter) { if (sma->complex_count) { list_add_tail(&queue.list, &sma->pending_alter); } else { list_add_tail(&queue.list, &curr->pending_alter); } } else { |
1a82e9e1d ipc/sem: separate... |
2039 |
list_add_tail(&queue.list, &curr->pending_const); |
f269f40ad ipc/sem.c: always... |
2040 |
} |
b97e820ff ipc/sem.c: add a ... |
2041 |
} else { |
f269f40ad ipc/sem.c: always... |
2042 2043 |
if (!sma->complex_count) merge_queues(sma); |
9f1bc2c90 ipc,sem: have onl... |
2044 |
if (alter) |
1a82e9e1d ipc/sem: separate... |
2045 |
list_add_tail(&queue.list, &sma->pending_alter); |
9f1bc2c90 ipc,sem: have onl... |
2046 |
else |
1a82e9e1d ipc/sem: separate... |
2047 |
list_add_tail(&queue.list, &sma->pending_const); |
b97e820ff ipc/sem.c: add a ... |
2048 2049 |
sma->complex_count++; } |
b5fa01a22 ipc/sem: simplify... |
2050 |
do { |
f075faa30 ipc/sem.c: preven... |
2051 |
WRITE_ONCE(queue.status, -EINTR); |
b5fa01a22 ipc/sem: simplify... |
2052 |
queue.sleeper = current; |
0b0577f60 ipc/sem.c: handle... |
2053 |
|
b5fa01a22 ipc/sem: simplify... |
2054 2055 2056 |
__set_current_state(TASK_INTERRUPTIBLE); sem_unlock(sma, locknum); rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
2057 |
|
b5fa01a22 ipc/sem: simplify... |
2058 2059 2060 2061 |
if (timeout) jiffies_left = schedule_timeout(jiffies_left); else schedule(); |
1da177e4c Linux-2.6.12-rc2 |
2062 |
|
9ae949fa3 ipc/sem: rework t... |
2063 |
/* |
b5fa01a22 ipc/sem: simplify... |
2064 2065 2066 2067 2068 2069 2070 2071 2072 |
* fastpath: the semop has completed, either successfully or * not, from the syscall pov, is quite irrelevant to us at this * point; we're done. * * We _do_ care, nonetheless, about being awoken by a signal or * spuriously. The queue.status is checked again in the * slowpath (aka after taking sem_lock), such that we can detect * scenarios where we were awakened externally, during the * window between wake_q_add() and wake_up_q(). |
c61284e99 ipc/sem.c: bugfix... |
2073 |
*/ |
b5fa01a22 ipc/sem: simplify... |
2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 |
error = READ_ONCE(queue.status); if (error != -EINTR) { /* * User space could assume that semop() is a memory * barrier: Without the mb(), the cpu could * speculatively read in userspace stale data that was * overwritten by the previous owner of the semaphore. */ smp_mb(); goto out_free; } |
d694ad62b ipc/sem.c: fix ra... |
2085 |
|
b5fa01a22 ipc/sem: simplify... |
2086 |
rcu_read_lock(); |
c626bc46e ipc/sem.c: fix in... |
2087 |
locknum = sem_lock(sma, sops, nsops); |
1da177e4c Linux-2.6.12-rc2 |
2088 |
|
370b262c8 ipc/sem: avoid id... |
2089 2090 2091 2092 |
if (!ipc_valid_object(&sma->sem_perm)) goto out_unlock_free; error = READ_ONCE(queue.status); |
1da177e4c Linux-2.6.12-rc2 |
2093 |
|
b5fa01a22 ipc/sem: simplify... |
2094 2095 2096 2097 2098 2099 |
/* * If queue.status != -EINTR we are woken up by another process. * Leave without unlink_queue(), but with sem_unlock(). */ if (error != -EINTR) goto out_unlock_free; |
0b0577f60 ipc/sem.c: handle... |
2100 |
|
b5fa01a22 ipc/sem: simplify... |
2101 2102 2103 2104 2105 2106 |
/* * If an interrupt occurred we have to clean up the queue. */ if (timeout && jiffies_left == 0) error = -EAGAIN; } while (error == -EINTR && !signal_pending(current)); /* spurious */ |
0b0577f60 ipc/sem.c: handle... |
2107 |
|
b97e820ff ipc/sem.c: add a ... |
2108 |
unlink_queue(sma, &queue); |
1da177e4c Linux-2.6.12-rc2 |
2109 2110 |
out_unlock_free: |
6062a8dc0 ipc,sem: fine gra... |
2111 |
sem_unlock(sma, locknum); |
6d49dab8a ipc: move rcu_rea... |
2112 |
rcu_read_unlock(); |
1da177e4c Linux-2.6.12-rc2 |
2113 |
out_free: |
239521f31 ipc: whitespace c... |
2114 |
if (sops != fast_sops) |
e4243b806 ipc/sem: play nic... |
2115 |
kvfree(sops); |
1da177e4c Linux-2.6.12-rc2 |
2116 2117 |
return error; } |
41f4f0e2f ipc: add semtimed... |
2118 |
long ksys_semtimedop(int semid, struct sembuf __user *tsops, |
21fc538d8 y2038: ipc: Use _... |
2119 |
unsigned int nsops, const struct __kernel_timespec __user *timeout) |
44ee45467 semtimedop(): mov... |
2120 2121 |
{ if (timeout) { |
3ef56dc26 ipc: Make sys_sem... |
2122 2123 |
struct timespec64 ts; if (get_timespec64(&ts, timeout)) |
44ee45467 semtimedop(): mov... |
2124 2125 2126 2127 2128 |
return -EFAULT; return do_semtimedop(semid, tsops, nsops, &ts); } return do_semtimedop(semid, tsops, nsops, NULL); } |
41f4f0e2f ipc: add semtimed... |
2129 |
SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsops, |
21fc538d8 y2038: ipc: Use _... |
2130 |
unsigned int, nsops, const struct __kernel_timespec __user *, timeout) |
41f4f0e2f ipc: add semtimed... |
2131 2132 2133 |
{ return ksys_semtimedop(semid, tsops, nsops, timeout); } |
b0d175781 y2038: ipc: Enabl... |
2134 |
#ifdef CONFIG_COMPAT_32BIT_TIME |
41f4f0e2f ipc: add semtimed... |
2135 2136 2137 |
long compat_ksys_semtimedop(int semid, struct sembuf __user *tsems, unsigned int nsops, const struct compat_timespec __user *timeout) |
44ee45467 semtimedop(): mov... |
2138 2139 |
{ if (timeout) { |
3ef56dc26 ipc: Make sys_sem... |
2140 2141 |
struct timespec64 ts; if (compat_get_timespec64(&ts, timeout)) |
44ee45467 semtimedop(): mov... |
2142 2143 2144 2145 2146 |
return -EFAULT; return do_semtimedop(semid, tsems, nsops, &ts); } return do_semtimedop(semid, tsems, nsops, NULL); } |
41f4f0e2f ipc: add semtimed... |
2147 2148 2149 2150 2151 2152 2153 |
COMPAT_SYSCALL_DEFINE4(semtimedop, int, semid, struct sembuf __user *, tsems, unsigned int, nsops, const struct compat_timespec __user *, timeout) { return compat_ksys_semtimedop(semid, tsems, nsops, timeout); } |
44ee45467 semtimedop(): mov... |
2154 |
#endif |
d5460c997 [CVE-2009-0029] S... |
2155 2156 |
SYSCALL_DEFINE3(semop, int, semid, struct sembuf __user *, tsops, unsigned, nsops) |
1da177e4c Linux-2.6.12-rc2 |
2157 |
{ |
44ee45467 semtimedop(): mov... |
2158 |
return do_semtimedop(semid, tsops, nsops, NULL); |
1da177e4c Linux-2.6.12-rc2 |
2159 2160 2161 2162 |
} /* If CLONE_SYSVSEM is set, establish sharing of SEM_UNDO state between * parent and child tasks. |
1da177e4c Linux-2.6.12-rc2 |
2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 |
*/ int copy_semundo(unsigned long clone_flags, struct task_struct *tsk) { struct sem_undo_list *undo_list; int error; if (clone_flags & CLONE_SYSVSEM) { error = get_undo_list(&undo_list); if (error) return error; |
f74370b86 ipc: convert sem_... |
2174 |
refcount_inc(&undo_list->refcnt); |
1da177e4c Linux-2.6.12-rc2 |
2175 |
tsk->sysvsem.undo_list = undo_list; |
46c0a8ca3 ipc, kernel: clea... |
2176 |
} else |
1da177e4c Linux-2.6.12-rc2 |
2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 |
tsk->sysvsem.undo_list = NULL; return 0; } /* * add semadj values to semaphores, free undo structures. * undo structures are not freed when semaphore arrays are destroyed * so some of them may be out of date. * IMPLEMENTATION NOTE: There is some confusion over whether the * set of adjustments that needs to be done should be done in an atomic * manner or not. That is, if we are attempting to decrement the semval * should we queue up and wait until we can do so legally? * The original implementation attempted to do this (queue and wait). * The current implementation does not do so. The POSIX standard * and SVID should be consulted to determine what behavior is mandated. */ void exit_sem(struct task_struct *tsk) { |
4daa28f6d ipc/sem.c: conver... |
2196 |
struct sem_undo_list *ulp; |
1da177e4c Linux-2.6.12-rc2 |
2197 |
|
4daa28f6d ipc/sem.c: conver... |
2198 2199 |
ulp = tsk->sysvsem.undo_list; if (!ulp) |
1da177e4c Linux-2.6.12-rc2 |
2200 |
return; |
9edff4ab1 ipc: sysvsem: imp... |
2201 |
tsk->sysvsem.undo_list = NULL; |
1da177e4c Linux-2.6.12-rc2 |
2202 |
|
f74370b86 ipc: convert sem_... |
2203 |
if (!refcount_dec_and_test(&ulp->refcnt)) |
1da177e4c Linux-2.6.12-rc2 |
2204 |
return; |
380af1b33 ipc/sem.c: rewrit... |
2205 |
for (;;) { |
1da177e4c Linux-2.6.12-rc2 |
2206 |
struct sem_array *sma; |
380af1b33 ipc/sem.c: rewrit... |
2207 |
struct sem_undo *un; |
6062a8dc0 ipc,sem: fine gra... |
2208 |
int semid, i; |
9ae949fa3 ipc/sem: rework t... |
2209 |
DEFINE_WAKE_Q(wake_q); |
4daa28f6d ipc/sem.c: conver... |
2210 |
|
2a1613a58 ipc/sem.c: add co... |
2211 |
cond_resched(); |
380af1b33 ipc/sem.c: rewrit... |
2212 |
rcu_read_lock(); |
05725f7eb rculist: use list... |
2213 2214 |
un = list_entry_rcu(ulp->list_proc.next, struct sem_undo, list_proc); |
602b8593d ipc,sem: fix use ... |
2215 2216 2217 2218 2219 2220 2221 |
if (&un->list_proc == &ulp->list_proc) { /* * We must wait for freeary() before freeing this ulp, * in case we raced with last sem_undo. There is a small * possibility where we exit while freeary() didn't * finish unlocking sem_undo_list. */ |
e0892e086 ipc: Replace spin... |
2222 2223 |
spin_lock(&ulp->lock); spin_unlock(&ulp->lock); |
602b8593d ipc,sem: fix use ... |
2224 2225 2226 2227 2228 2229 |
rcu_read_unlock(); break; } spin_lock(&ulp->lock); semid = un->semid; spin_unlock(&ulp->lock); |
4daa28f6d ipc/sem.c: conver... |
2230 |
|
602b8593d ipc,sem: fix use ... |
2231 |
/* exit_sem raced with IPC_RMID, nothing to do */ |
6062a8dc0 ipc,sem: fine gra... |
2232 2233 |
if (semid == -1) { rcu_read_unlock(); |
602b8593d ipc,sem: fix use ... |
2234 |
continue; |
6062a8dc0 ipc,sem: fine gra... |
2235 |
} |
1da177e4c Linux-2.6.12-rc2 |
2236 |
|
602b8593d ipc,sem: fix use ... |
2237 |
sma = sem_obtain_object_check(tsk->nsproxy->ipc_ns, semid); |
380af1b33 ipc/sem.c: rewrit... |
2238 |
/* exit_sem raced with IPC_RMID, nothing to do */ |
6062a8dc0 ipc,sem: fine gra... |
2239 2240 |
if (IS_ERR(sma)) { rcu_read_unlock(); |
380af1b33 ipc/sem.c: rewrit... |
2241 |
continue; |
6062a8dc0 ipc,sem: fine gra... |
2242 |
} |
1da177e4c Linux-2.6.12-rc2 |
2243 |
|
6062a8dc0 ipc,sem: fine gra... |
2244 |
sem_lock(sma, NULL, -1); |
6e224f945 ipc/sem.c: synchr... |
2245 |
/* exit_sem raced with IPC_RMID, nothing to do */ |
0f3d2b013 ipc: introduce ip... |
2246 |
if (!ipc_valid_object(&sma->sem_perm)) { |
6e224f945 ipc/sem.c: synchr... |
2247 2248 2249 2250 |
sem_unlock(sma, -1); rcu_read_unlock(); continue; } |
bf17bb717 ipc/sem.c: sem op... |
2251 |
un = __lookup_undo(ulp, semid); |
380af1b33 ipc/sem.c: rewrit... |
2252 2253 2254 2255 |
if (un == NULL) { /* exit_sem raced with IPC_RMID+semget() that created * exactly the same semid. Nothing to do. */ |
6062a8dc0 ipc,sem: fine gra... |
2256 |
sem_unlock(sma, -1); |
6d49dab8a ipc: move rcu_rea... |
2257 |
rcu_read_unlock(); |
380af1b33 ipc/sem.c: rewrit... |
2258 2259 2260 2261 |
continue; } /* remove un from the linked lists */ |
cf9d5d78d ipc: close open c... |
2262 |
ipc_assert_locked_object(&sma->sem_perm); |
4daa28f6d ipc/sem.c: conver... |
2263 |
list_del(&un->list_id); |
a97955844 ipc,sem: remove u... |
2264 2265 2266 2267 |
/* we are the last process using this ulp, acquiring ulp->lock * isn't required. Besides that, we are also protected against * IPC_RMID as we hold sma->sem_perm lock now */ |
380af1b33 ipc/sem.c: rewrit... |
2268 |
list_del_rcu(&un->list_proc); |
380af1b33 ipc/sem.c: rewrit... |
2269 |
|
4daa28f6d ipc/sem.c: conver... |
2270 2271 |
/* perform adjustments registered in un */ for (i = 0; i < sma->sem_nsems; i++) { |
1a2339567 ipc/sem.c: remove... |
2272 |
struct sem *semaphore = &sma->sems[i]; |
4daa28f6d ipc/sem.c: conver... |
2273 2274 |
if (un->semadj[i]) { semaphore->semval += un->semadj[i]; |
1da177e4c Linux-2.6.12-rc2 |
2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 |
/* * Range checks of the new semaphore value, * not defined by sus: * - Some unices ignore the undo entirely * (e.g. HP UX 11i 11.22, Tru64 V5.1) * - some cap the value (e.g. FreeBSD caps * at 0, but doesn't enforce SEMVMX) * * Linux caps the semaphore value, both at 0 * and at SEMVMX. * |
239521f31 ipc: whitespace c... |
2286 |
* Manfred <manfred@colorfullife.com> |
1da177e4c Linux-2.6.12-rc2 |
2287 |
*/ |
5f921ae96 [PATCH] sem2mutex... |
2288 2289 2290 2291 |
if (semaphore->semval < 0) semaphore->semval = 0; if (semaphore->semval > SEMVMX) semaphore->semval = SEMVMX; |
51d6f2635 ipc/sem: Fix semc... |
2292 |
ipc_update_pid(&semaphore->sempid, task_tgid(current)); |
1da177e4c Linux-2.6.12-rc2 |
2293 2294 |
} } |
1da177e4c Linux-2.6.12-rc2 |
2295 |
/* maybe some queued-up processes were waiting for this */ |
9ae949fa3 ipc/sem: rework t... |
2296 |
do_smart_update(sma, NULL, 0, 1, &wake_q); |
6062a8dc0 ipc,sem: fine gra... |
2297 |
sem_unlock(sma, -1); |
6d49dab8a ipc: move rcu_rea... |
2298 |
rcu_read_unlock(); |
9ae949fa3 ipc/sem: rework t... |
2299 |
wake_up_q(&wake_q); |
380af1b33 ipc/sem.c: rewrit... |
2300 |
|
693a8b6ee ipc,rcu: Convert ... |
2301 |
kfree_rcu(un, rcu); |
1da177e4c Linux-2.6.12-rc2 |
2302 |
} |
4daa28f6d ipc/sem.c: conver... |
2303 |
kfree(ulp); |
1da177e4c Linux-2.6.12-rc2 |
2304 2305 2306 |
} #ifdef CONFIG_PROC_FS |
19b4946ca [PATCH] ipc: conv... |
2307 |
static int sysvipc_sem_proc_show(struct seq_file *s, void *it) |
1da177e4c Linux-2.6.12-rc2 |
2308 |
{ |
1efdb69b0 userns: Convert i... |
2309 |
struct user_namespace *user_ns = seq_user_ns(s); |
ade9f91b3 ipc: add missing ... |
2310 2311 |
struct kern_ipc_perm *ipcp = it; struct sem_array *sma = container_of(ipcp, struct sem_array, sem_perm); |
e54d02b23 ipc: sem: Make se... |
2312 |
time64_t sem_otime; |
d12e1e50e ipc/sem.c: replac... |
2313 |
|
d8c633766 ipc/sem.c: synchr... |
2314 2315 2316 |
/* * The proc interface isn't aware of sem_lock(), it calls * ipc_lock_object() directly (in sysvipc_find_ipc). |
5864a2fd3 ipc/sem.c: fix co... |
2317 2318 |
* In order to stay compatible with sem_lock(), we must * enter / leave complex_mode. |
d8c633766 ipc/sem.c: synchr... |
2319 |
*/ |
5864a2fd3 ipc/sem.c: fix co... |
2320 |
complexmode_enter(sma); |
d8c633766 ipc/sem.c: synchr... |
2321 |
|
d12e1e50e ipc/sem.c: replac... |
2322 |
sem_otime = get_semotime(sma); |
19b4946ca [PATCH] ipc: conv... |
2323 |
|
7f032d6ef ipc: remove use o... |
2324 |
seq_printf(s, |
e54d02b23 ipc: sem: Make se... |
2325 2326 |
"%10d %10d %4o %10u %5u %5u %5u %5u %10llu %10llu ", |
7f032d6ef ipc: remove use o... |
2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 |
sma->sem_perm.key, sma->sem_perm.id, sma->sem_perm.mode, sma->sem_nsems, from_kuid_munged(user_ns, sma->sem_perm.uid), from_kgid_munged(user_ns, sma->sem_perm.gid), from_kuid_munged(user_ns, sma->sem_perm.cuid), from_kgid_munged(user_ns, sma->sem_perm.cgid), sem_otime, sma->sem_ctime); |
5864a2fd3 ipc/sem.c: fix co... |
2337 |
complexmode_tryleave(sma); |
7f032d6ef ipc: remove use o... |
2338 |
return 0; |
1da177e4c Linux-2.6.12-rc2 |
2339 2340 |
} #endif |