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sysv_sem: semusz depends on semume.

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Size of the per-process semaphore undo structure (semusz) depends on
the number of the per-process undos.  If kern.ipc.semume is adjusted,
semusz must be adjusted as well, and it makes no sense to delegate
adjustment to user.  Make it automatic.

Reported and tested by:	Olef <o.vandestadt@gmail.com>
PR:	250361
Reviewed by:	jhb, markj
Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
Differential revision:	https://reviews.freebsd.org/D26826
This commit is contained in:
Konstantin Belousov 2020-10-22 09:28:11 +00:00
parent 2ae634c6db
commit 18b8496c23
1 changed files with 5 additions and 4 deletions
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9
sys/kern/sysv_sem.c
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@ -187,13 +187,13 @@ struct sem_undo {
#define SEM_ALIGN(bytes) roundup2(bytes, sizeof(long))
/* actual size of an undo structure */
#define SEMUSZ SEM_ALIGN(offsetof(struct sem_undo, un_ent[SEMUME]))
#define SEMUSZ(x) SEM_ALIGN(offsetof(struct sem_undo, un_ent[(x)]))
/*
* Macro to find a particular sem_undo vector
*/
#define SEMU(ix) \
((struct sem_undo *)(((intptr_t)semu)+ix * seminfo.semusz))
((struct sem_undo *)(((intptr_t)semu) + (ix) * seminfo.semusz))
/*
* semaphore info struct
@ -205,7 +205,7 @@ struct seminfo seminfo = {
.semmsl = SEMMSL, /* max # of semaphores per id */
.semopm = SEMOPM, /* max # of operations per semop call */
.semume = SEMUME, /* max # of undo entries per process */
.semusz = SEMUSZ, /* size in bytes of undo structure */
.semusz = SEMUSZ(SEMUME), /* size in bytes of undo structure */
.semvmx = SEMVMX, /* semaphore maximum value */
.semaem = SEMAEM, /* adjust on exit max value */
};
@ -222,7 +222,7 @@ 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,
SYSCTL_INT(_kern_ipc, OID_AUTO, semusz, CTLFLAG_RD, &seminfo.semusz, 0,
"Size in bytes of undo structure");
SYSCTL_INT(_kern_ipc, OID_AUTO, semvmx, CTLFLAG_RWTUN, &seminfo.semvmx, 0,
"Semaphore maximum value");
@ -284,6 +284,7 @@ seminit(void)
M_WAITOK | M_ZERO);
sema_mtx = malloc(sizeof(struct mtx) * seminfo.semmni, M_SEM,
M_WAITOK | M_ZERO);
seminfo.semusz = SEMUSZ(seminfo.semume);
semu = malloc(seminfo.semmnu * seminfo.semusz, M_SEM, M_WAITOK);
for (i = 0; i < seminfo.semmni; i++) {