mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-10 02:29:01 +00:00
2cd648c110
sem_ctime is initialized to the semget() time and then updated at every semctl() that changes the array. Thus it does not represent the time of the last change. Especially, semop() calls are only stored in sem_otime, not in sem_ctime. This is already described in ipc/sem.c, I just overlooked that there is a comment in include/linux/sem.h and man semctl(2) as well. So: Correct wrong comments. Link: http://lkml.kernel.org/r/20170515171912.6298-4-manfred@colorfullife.com Signed-off-by: Manfred Spraul <manfred@colorfullife.com> Cc: Kees Cook <keescook@chromium.org> Cc: <1vier1@web.de> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Fabian Frederick <fabf@skynet.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
92 lines
2.9 KiB
C
92 lines
2.9 KiB
C
#ifndef _UAPI_LINUX_SEM_H
|
|
#define _UAPI_LINUX_SEM_H
|
|
|
|
#include <linux/ipc.h>
|
|
|
|
/* semop flags */
|
|
#define SEM_UNDO 0x1000 /* undo the operation on exit */
|
|
|
|
/* semctl Command Definitions. */
|
|
#define GETPID 11 /* get sempid */
|
|
#define GETVAL 12 /* get semval */
|
|
#define GETALL 13 /* get all semval's */
|
|
#define GETNCNT 14 /* get semncnt */
|
|
#define GETZCNT 15 /* get semzcnt */
|
|
#define SETVAL 16 /* set semval */
|
|
#define SETALL 17 /* set all semval's */
|
|
|
|
/* ipcs ctl cmds */
|
|
#define SEM_STAT 18
|
|
#define SEM_INFO 19
|
|
|
|
/* Obsolete, used only for backwards compatibility and libc5 compiles */
|
|
struct semid_ds {
|
|
struct ipc_perm sem_perm; /* permissions .. see ipc.h */
|
|
__kernel_time_t sem_otime; /* last semop time */
|
|
__kernel_time_t sem_ctime; /* create/last semctl() time */
|
|
struct sem *sem_base; /* ptr to first semaphore in array */
|
|
struct sem_queue *sem_pending; /* pending operations to be processed */
|
|
struct sem_queue **sem_pending_last; /* last pending operation */
|
|
struct sem_undo *undo; /* undo requests on this array */
|
|
unsigned short sem_nsems; /* no. of semaphores in array */
|
|
};
|
|
|
|
/* Include the definition of semid64_ds */
|
|
#include <asm/sembuf.h>
|
|
|
|
/* semop system calls takes an array of these. */
|
|
struct sembuf {
|
|
unsigned short sem_num; /* semaphore index in array */
|
|
short sem_op; /* semaphore operation */
|
|
short sem_flg; /* operation flags */
|
|
};
|
|
|
|
/* arg for semctl system calls. */
|
|
union semun {
|
|
int val; /* value for SETVAL */
|
|
struct semid_ds __user *buf; /* buffer for IPC_STAT & IPC_SET */
|
|
unsigned short __user *array; /* array for GETALL & SETALL */
|
|
struct seminfo __user *__buf; /* buffer for IPC_INFO */
|
|
void __user *__pad;
|
|
};
|
|
|
|
struct seminfo {
|
|
int semmap;
|
|
int semmni;
|
|
int semmns;
|
|
int semmnu;
|
|
int semmsl;
|
|
int semopm;
|
|
int semume;
|
|
int semusz;
|
|
int semvmx;
|
|
int semaem;
|
|
};
|
|
|
|
/*
|
|
* SEMMNI, SEMMSL and SEMMNS are default values which can be
|
|
* modified by sysctl.
|
|
* The values has been chosen to be larger than necessary for any
|
|
* known configuration.
|
|
*
|
|
* SEMOPM should not be increased beyond 1000, otherwise there is the
|
|
* risk that semop()/semtimedop() fails due to kernel memory fragmentation when
|
|
* allocating the sop array.
|
|
*/
|
|
|
|
|
|
#define SEMMNI 32000 /* <= IPCMNI max # of semaphore identifiers */
|
|
#define SEMMSL 32000 /* <= INT_MAX max num of semaphores per id */
|
|
#define SEMMNS (SEMMNI*SEMMSL) /* <= INT_MAX max # of semaphores in system */
|
|
#define SEMOPM 500 /* <= 1 000 max num of ops per semop call */
|
|
#define SEMVMX 32767 /* <= 32767 semaphore maximum value */
|
|
#define SEMAEM SEMVMX /* adjust on exit max value */
|
|
|
|
/* unused */
|
|
#define SEMUME SEMOPM /* max num of undo entries per process */
|
|
#define SEMMNU SEMMNS /* num of undo structures system wide */
|
|
#define SEMMAP SEMMNS /* # of entries in semaphore map */
|
|
#define SEMUSZ 20 /* sizeof struct sem_undo */
|
|
|
|
|
|
#endif /* _UAPI_LINUX_SEM_H */
|