diff options
Diffstat (limited to 'ipc/sem.c')
| -rw-r--r-- | ipc/sem.c | 34 |
1 files changed, 34 insertions, 0 deletions
diff --git a/ipc/sem.c b/ipc/sem.c index 01f5c63670ae..d661c491b0a5 100644 --- a/ipc/sem.c +++ b/ipc/sem.c @@ -88,6 +88,40 @@ #include <linux/uaccess.h> #include "util.h" +/* 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). + */ + int sempid; + 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*/ + time_t sem_otime; /* candidate for sem_otime */ +} ____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; /* One queue for each sleeping process in the system. */ struct sem_queue { |