sysv_sem.c File Reference

#include <sys/cdefs.h>
#include "opt_compat.h"
#include "opt_sysvipc.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysproto.h>
#include <sys/eventhandler.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/lock.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/racct.h>
#include <sys/sem.h>
#include <sys/syscall.h>
#include <sys/syscallsubr.h>
#include <sys/sysent.h>
#include <sys/sysctl.h>
#include <sys/uio.h>
#include <sys/malloc.h>
#include <sys/jail.h>
#include <security/mac/mac_framework.h>

Include dependency graph for sysv_sem.c:

Go to the source code of this file.

Data Structures
struct	sem_undo
struct	__semctl_args
struct	semget_args
struct	semop_args

Macros
#define	DPRINTF(a)
#define	SEMUNDO_MTX   sem_undo_mtx
#define	SEMUNDO_LOCK()   mtx_lock(&SEMUNDO_MTX);
#define	SEMUNDO_UNLOCK()   mtx_unlock(&SEMUNDO_MTX);
#define	SEMUNDO_LOCKASSERT(how)   mtx_assert(&SEMUNDO_MTX, (how));
#define	SEMMNI   50 /* # of semaphore identifiers */
#define	SEMMNS   340 /* # of semaphores in system */
#define	SEMUME   50 /* max # of undo entries per process */
#define	SEMMNU   150 /* # of undo structures in system */
#define	SEMMSL   SEMMNS /* max # of semaphores per id */
#define	SEMOPM   100 /* max # of operations per semop call */
#define	SEMVMX   32767 /* semaphore maximum value */
#define	SEMAEM   16384 /* adjust on exit max value */
#define	SEM_ALIGN(bytes)   (((bytes) + (sizeof(long) - 1)) & ~(sizeof(long) - 1))
#define	SEMUSZ   SEM_ALIGN(offsetof(struct sem_undo, un_ent[SEMUME]))
#define	SEMU(ix)   ((struct sem_undo *)(((intptr_t)semu)+ix * seminfo.semusz))
#define	SMALL_SOPS   8

Functions
	__FBSDID ("$BSDSUniX$")
	FEATURE (sysv_sem,"System V semaphores support")
static	MALLOC_DEFINE (M_SEM,"sem","SVID compatible semaphores")
static int	seminit (void)
static int	sysvsem_modload (struct module *, int, void *)
static int	semunload (void)
static void	semexit_myhook (void *arg, struct proc *p)
static int	sysctl_sema (SYSCTL_HANDLER_ARGS)
static int	semvalid (int semid, struct semid_kernel *semakptr)
int	__semctl (struct thread *td, struct __semctl_args *uap)
int	semget (struct thread *td, struct semget_args *uap)
int	semop (struct thread *td, struct semop_args *uap)
static struct sem_undo *	semu_alloc (struct thread *td)
static int	semundo_adjust (struct thread *td, struct sem_undo **supptr, int semid, int semseq, int semnum, int adjval)
static void	semundo_clear (int semid, int semnum)
	LIST_HEAD (sem_undo)
	SYSCTL_INT (_kern_ipc, OID_AUTO, semmni, CTLFLAG_RDTUN,&seminfo.semmni, 0,"Number of semaphore identifiers")
	SYSCTL_INT (_kern_ipc, OID_AUTO, semmns, CTLFLAG_RDTUN,&seminfo.semmns, 0,"Maximum number of semaphores in the system")
	SYSCTL_INT (_kern_ipc, OID_AUTO, semmnu, CTLFLAG_RDTUN,&seminfo.semmnu, 0,"Maximum number of undo structures in the system")
	SYSCTL_INT (_kern_ipc, OID_AUTO, semmsl, CTLFLAG_RW,&seminfo.semmsl, 0,"Max semaphores per id")
	SYSCTL_INT (_kern_ipc, OID_AUTO, semopm, CTLFLAG_RDTUN,&seminfo.semopm, 0,"Max operations per semop call")
	SYSCTL_INT (_kern_ipc, OID_AUTO, semume, CTLFLAG_RDTUN,&seminfo.semume, 0,"Max undo entries per process")
	SYSCTL_INT (_kern_ipc, OID_AUTO, semusz, CTLFLAG_RDTUN,&seminfo.semusz, 0,"Size in bytes of undo structure")
	SYSCTL_INT (_kern_ipc, OID_AUTO, semvmx, CTLFLAG_RW,&seminfo.semvmx, 0,"Semaphore maximum value")
	SYSCTL_INT (_kern_ipc, OID_AUTO, semaem, CTLFLAG_RW,&seminfo.semaem, 0,"Adjust on exit max value")
	SYSCTL_PROC (_kern_ipc, OID_AUTO, sema, CTLTYPE_OPAQUE|CTLFLAG_RD, NULL, 0, sysctl_sema,"","Semaphore id pool")
	DECLARE_MODULE (sysvsem, sysvsem_mod, SI_SUB_SYSV_SEM, SI_ORDER_FIRST)
	MODULE_VERSION (sysvsem, 1)
static int	semu_try_free (struct sem_undo *suptr)
int	sys___semctl (struct thread *td, struct __semctl_args *uap)
int	kern_semctl (struct thread *td, int semid, int semnum, int cmd, union semun *arg, register_t *rval)
int	sys_semget (struct thread *td, struct semget_args *uap)
int	sys_semop (struct thread *td, struct semop_args *uap)

Variables
static struct mtx	sem_mtx
static struct mtx	sem_undo_mtx
static int	semtot = 0
static struct semid_kernel *	sema
static struct mtx *	sema_mtx
static struct sem *	sem
struct seminfo	seminfo
static struct syscall_helper_data	sem_syscalls []
static moduledata_t	sysvsem_mod

Macro Definition Documentation

#define DPRINTF

(

a

)

Definition at line 73 of file sysv_sem.c.

Referenced by kern_semctl(), semexit_myhook(), sys_semget(), and sys_semop().

#define SEM_ALIGN

(

bytes

)

(((bytes) + (sizeof(long) - 1)) & ~(sizeof(long) - 1))

Definition at line 167 of file sysv_sem.c.

#define SEMAEM   16384 /* adjust on exit max value */

Definition at line 160 of file sysv_sem.c.

#define SEMMNI   50 /* # of semaphore identifiers */

Definition at line 139 of file sysv_sem.c.

#define SEMMNS   340 /* # of semaphores in system */

Definition at line 142 of file sysv_sem.c.

#define SEMMNU   150 /* # of undo structures in system */

Definition at line 148 of file sysv_sem.c.

#define SEMMSL   SEMMNS /* max # of semaphores per id */

Definition at line 153 of file sysv_sem.c.

#define SEMOPM   100 /* max # of operations per semop call */

Definition at line 156 of file sysv_sem.c.

#define SEMU

(

ix

)

((struct sem_undo *)(((intptr_t)semu)+ix * seminfo.semusz))

Definition at line 175 of file sysv_sem.c.

Referenced by seminit().

#define SEMUME   50 /* max # of undo entries per process */

Definition at line 145 of file sysv_sem.c.

#define SEMUNDO_LOCK

(

)

mtx_lock(&SEMUNDO_MTX);

Referenced by kern_semctl(), semexit_myhook(), and sys_semop().

#define SEMUNDO_LOCKASSERT

(

how

)

mtx_assert(&SEMUNDO_MTX, (how));

Referenced by semu_alloc(), semu_try_free(), semundo_adjust(), and semundo_clear().

#define SEMUNDO_MTX   sem_undo_mtx

#define SEMUNDO_UNLOCK

(

)

mtx_unlock(&SEMUNDO_MTX);

Referenced by kern_semctl(), semexit_myhook(), and sys_semop().

#define SEMUSZ   SEM_ALIGN(offsetof(struct sem_undo, un_ent[SEMUME]))

Definition at line 170 of file sysv_sem.c.

#define SEMVMX   32767 /* semaphore maximum value */

Definition at line 159 of file sysv_sem.c.

#define SMALL_SOPS   8

Function Documentation

__FBSDID

(

"$BSDSUniX$"

)

int __semctl	(	struct thread *	td,
		struct __semctl_args *	uap
	)

DECLARE_MODULE	(	sysvsem	,
		sysvsem_mod	,
		SI_SUB_SYSV_SEM	,
		SI_ORDER_FIRST
	)

FEATURE	(	sysv_sem	,
		"System V semaphores support"
	)

int kern_semctl	(	struct thread *	td,
		int	semid,
		int	semnum,
		int	cmd,
		union semun *	arg,
		register_t *	rval
	)

Definition at line 579 of file sysv_sem.c.

References count, crfree(), DPRINTF, free(), ipcperm(), malloc(), prison_allow(), racct_sub_cred(), sem, sem_mtx, sema, sema_mtx, semtot, semundo_clear(), SEMUNDO_LOCK, SEMUNDO_UNLOCK, semvalid(), time_second, and wakeup().

Referenced by sys___semctl().

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LIST_HEAD

(

sem_undo

)

Definition at line 103 of file sysv_sem.c.

static MALLOC_DEFINE ( M_SEM  , "sem"  , "SVID compatible semaphores"    )

static

MODULE_VERSION	(	sysvsem	,
		1
	)

static void semexit_myhook ( void *  arg, struct proc *  p  )

static

Definition at line 1294 of file sysv_sem.c.

References DPRINTF, panic(), sema, sema_mtx, SEMUNDO_LOCK, SEMUNDO_UNLOCK, sem_undo::un_ent, and wakeup().

Referenced by seminit().

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int semget	(	struct thread *	td,
		struct semget_args *	uap
	)

static int seminit ( void  )

static

Definition at line 248 of file sysv_sem.c.

References malloc(), mtx_init(), sem, sem_mtx, sem_undo_mtx, sema, sema_mtx, semexit_myhook(), SEMU, and syscall_helper_register().

Referenced by sysvsem_modload().

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int semop	(	struct thread *	td,
		struct semop_args *	uap
	)

static struct sem_undo * semu_alloc ( struct thread *  td )

static

Definition at line 369 of file sysv_sem.c.

References SEMUNDO_LOCKASSERT.

Referenced by semundo_adjust().

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static int semu_try_free ( struct sem_undo *  suptr )

static

Definition at line 384 of file sysv_sem.c.

References SEMUNDO_LOCKASSERT.

Referenced by semundo_adjust(), and semundo_clear().

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static int semundo_adjust ( struct thread *  td, struct sem_undo **  supptr, int  semid, int  semseq, int  semnum, int  adjval  )

static

Definition at line 401 of file sysv_sem.c.

References semu_alloc(), semu_try_free(), SEMUNDO_LOCKASSERT, and sem_undo::un_ent.

Referenced by sys_semop().

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static void semundo_clear ( int  semid, int  semnum  )

static

Definition at line 474 of file sysv_sem.c.

References semu_try_free(), SEMUNDO_LOCKASSERT, and sem_undo::un_ent.

Referenced by kern_semctl().

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static int semunload ( void  )

static

Definition at line 303 of file sysv_sem.c.

References free(), mtx_destroy(), sem, sem_mtx, sem_undo_mtx, sema, sema_mtx, semtot, and syscall_helper_unregister().

Referenced by sysvsem_modload().

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static int semvalid ( int  semid, struct semid_kernel *  semakptr  )

static

Definition at line 502 of file sysv_sem.c.

Referenced by kern_semctl().

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int sys___semctl	(	struct thread *	td,
		struct __semctl_args *	uap
	)

Definition at line 521 of file sysv_sem.c.

References __semctl_args::arg, __semctl_args::cmd, kern_semctl(), __semctl_args::semid, and __semctl_args::semnum.

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int sys_semget	(	struct thread *	td,
		struct semget_args *	uap
	)

Definition at line 859 of file sysv_sem.c.

References crhold(), DPRINTF, ipcperm(), semget_args::key, semget_args::nsems, prison_allow(), racct_add(), sem, sem_mtx, sema, sema_mtx, semget_args::semflg, semtot, and time_second.

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int sys_semop	(	struct thread *	td,
		struct semop_args *	uap
	)

Definition at line 983 of file sysv_sem.c.

References DPRINTF, free(), ipcperm(), malloc(), semop_args::nsops, panic(), prison_allow(), racct_get_available(), sem, sema, sema_mtx, semop_args::semid, semundo_adjust(), SEMUNDO_LOCK, SEMUNDO_UNLOCK, semop_args::sops, time_second, and wakeup().

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SYSCTL_INT	(	_kern_ipc	,
		OID_AUTO	,
		semmni	,
		CTLFLAG_RDTUN	,
		&seminfo.	semmni,
		0	,
		"Number of semaphore identifiers"
	)

SYSCTL_INT	(	_kern_ipc	,
		OID_AUTO	,
		semmns	,
		CTLFLAG_RDTUN	,
		&seminfo.	semmns,
		0	,
		"Maximum number of semaphores in the system"
	)

SYSCTL_INT	(	_kern_ipc	,
		OID_AUTO	,
		semmnu	,
		CTLFLAG_RDTUN	,
		&seminfo.	semmnu,
		0	,
		"Maximum number of undo structures in the system"
	)

SYSCTL_INT	(	_kern_ipc	,
		OID_AUTO	,
		semmsl	,
		CTLFLAG_RW	,
		&seminfo.	semmsl,
		0	,
		"Max semaphores per id"
	)

SYSCTL_INT	(	_kern_ipc	,
		OID_AUTO	,
		semopm	,
		CTLFLAG_RDTUN	,
		&seminfo.	semopm,
		0	,
		"Max operations per semop call"
	)

SYSCTL_INT	(	_kern_ipc	,
		OID_AUTO	,
		semume	,
		CTLFLAG_RDTUN	,
		&seminfo.	semume,
		0	,
		"Max undo entries per process"
	)

SYSCTL_INT	(	_kern_ipc	,
		OID_AUTO	,
		semusz	,
		CTLFLAG_RDTUN	,
		&seminfo.	semusz,
		0	,
		"Size in bytes of undo structure"
	)

SYSCTL_INT	(	_kern_ipc	,
		OID_AUTO	,
		semvmx	,
		CTLFLAG_RW	,
		&seminfo.	semvmx,
		0	,
		"Semaphore maximum value"
	)

SYSCTL_INT	(	_kern_ipc	,
		OID_AUTO	,
		semaem	,
		CTLFLAG_RW	,
		&seminfo.	semaem,
		0	,
		"Adjust on exit max value"
	)

SYSCTL_PROC	(	_kern_ipc	,
		OID_AUTO	,
		sema	,
		CTLTYPE_OPAQUE|	CTLFLAG_RD,
		NULL	,
		0	,
		sysctl_sema	,
		""	,
		"Semaphore id pool"
	)

static int sysctl_sema ( SYSCTL_HANDLER_ARGS  )

static

Definition at line 1373 of file sysv_sem.c.

References sema.

static int sysvsem_modload ( struct module *  module, int  cmd, void *  arg  )

static

Definition at line 332 of file sysv_sem.c.

References seminit(), and semunload().

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Variable Documentation

struct sem* sem

static

Definition at line 102 of file sysv_sem.c.

Referenced by kern_semctl(), seminit(), semunload(), sys_semget(), and sys_semop().

struct mtx sem_mtx

static

Definition at line 97 of file sysv_sem.c.

Referenced by kern_semctl(), seminit(), semunload(), and sys_semget().

struct syscall_helper_data sem_syscalls[]

static

Initial value:

= {
        SYSCALL_INIT_HELPER(__semctl),
        SYSCALL_INIT_HELPER(semget),
        SYSCALL_INIT_HELPER(semop),





        SYSCALL_INIT_LAST
}

Definition at line 214 of file sysv_sem.c.

struct mtx sem_undo_mtx

static

Definition at line 98 of file sysv_sem.c.

Referenced by seminit(), and semunload().

struct semid_kernel* sema

static

Definition at line 100 of file sysv_sem.c.

Referenced by kern_semctl(), semexit_myhook(), seminit(), semunload(), sys_semget(), sys_semop(), and sysctl_sema().

struct mtx* sema_mtx

static

Definition at line 101 of file sysv_sem.c.

Referenced by kern_semctl(), semexit_myhook(), seminit(), semunload(), sys_semget(), and sys_semop().

struct seminfo seminfo

Initial value:

= {
                SEMMNI,         
                SEMMNS,         
                SEMMNU,         
                SEMMSL,         
                SEMOPM,         
                SEMUME,         
                SEMUSZ,         
                SEMVMX,         
                SEMAEM          
}

Definition at line 181 of file sysv_sem.c.

int semtot = 0

static

Definition at line 99 of file sysv_sem.c.

Referenced by kern_semctl(), semunload(), and sys_semget().

moduledata_t sysvsem_mod

static

Initial value:

= {
        "sysvsem",
        &sysvsem_modload,
        NULL
}

Definition at line 354 of file sysv_sem.c.