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Corrected an error where precious kernel virtual space was being allocated

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for entire SYS5 SHM segments.  This is totally unnecessary, and so the
correct allocation of VM objects has been substituted.  (The vm_mmap
was misused -- vm_object_allocate is more appropriate.)
This commit is contained in:
John Dyson 1996-09-07 03:24:44 +00:00
parent 163d0a5fb8
commit a51f711975
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=18098
1 changed files with 21 additions and 26 deletions
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47
sys/kern/sysv_shm.c
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@ -1,4 +1,4 @@
/* $Id: sysv_shm.c,v 1.20 1996/05/03 21:01:24 phk Exp $ */
/* $Id: sysv_shm.c,v 1.21 1996/05/05 13:53:48 joerg Exp $ */
/* $NetBSD: sysv_shm.c,v 1.23 1994/07/04 23:25:12 glass Exp $ */
/*
@ -49,6 +49,7 @@
#include <vm/vm_prot.h>
#include <vm/lock.h>
#include <vm/pmap.h>
#include <vm/vm_object.h>
#include <vm/vm_map.h>
#include <vm/vm_kern.h>
#include <vm/vm_extern.h>
@ -84,12 +85,12 @@ sy_call_t *shmcalls[] = {
#define SHMSEG_ALLOCATED 0x0800
#define SHMSEG_WANTED 0x1000
static vm_map_t sysvshm_map;
static int shm_last_free, shm_nused, shm_committed;
struct shmid_ds *shmsegs;
struct shm_handle {
vm_offset_t kva;
/* vm_offset_t kva; */
vm_object_t shm_object;
};
struct shmmap_state {
@ -141,10 +142,10 @@ shm_deallocate_segment(shmseg)
size_t size;
shm_handle = shmseg->shm_internal;
size = round_page(shmseg->shm_segsz);
(void) vm_map_remove(sysvshm_map, shm_handle->kva, shm_handle->kva + size);
vm_object_deallocate(shm_handle->shm_object);
free((caddr_t)shm_handle, M_SHM);
shmseg->shm_internal = NULL;
size = round_page(shmseg->shm_segsz);
shm_committed -= btoc(size);
shm_nused--;
shmseg->shm_perm.mode = SHMSEG_FREE;
@ -220,9 +221,11 @@ shmat(p, uap, retval)
struct ucred *cred = p->p_ucred;
struct shmid_ds *shmseg;
struct shmmap_state *shmmap_s = NULL;
struct shm_handle *shm_handle;
vm_offset_t attach_va;
vm_prot_t prot;
vm_size_t size;
int rv;
shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
if (shmmap_s == NULL) {
@ -260,13 +263,17 @@ shmat(p, uap, retval)
else
return EINVAL;
} else {
/* This is just a hint to vm_mmap() about where to put it. */
/* This is just a hint to vm_map_find() about where to put it. */
attach_va = round_page(p->p_vmspace->vm_taddr + MAXTSIZ + MAXDSIZ);
}
error = vm_mmap(&p->p_vmspace->vm_map, &attach_va, size, prot,
VM_PROT_DEFAULT, flags, (caddr_t) uap->shmid, 0);
if (error)
return error;
shm_handle = shmseg->shm_internal;
vm_object_reference(shm_handle->shm_object);
rv = vm_map_find(&p->p_vmspace->vm_map, shm_handle->shm_object,
0, &attach_va, size, (flags & MAP_FIXED)?0:1, prot, prot, 0);
if (rv != KERN_SUCCESS) {
return ENOMEM;
}
shmmap_s->va = attach_va;
shmmap_s->shmid = uap->shmid;
shmseg->shm_lpid = p->p_pid;
@ -454,7 +461,7 @@ shmget_allocate_segment(p, uap, mode, retval)
int mode;
int *retval;
{
int i, segnum, result, shmid, size;
int i, segnum, shmid, size;
struct ucred *cred = p->p_ucred;
struct shmid_ds *shmseg;
struct shm_handle *shm_handle;
@ -488,16 +495,9 @@ shmget_allocate_segment(p, uap, mode, retval)
shm_handle = (struct shm_handle *)
malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK);
shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
result = vm_mmap(sysvshm_map, &shm_handle->kva, size, VM_PROT_ALL,
VM_PROT_DEFAULT, MAP_ANON, (caddr_t) shmid, 0);
if (result != KERN_SUCCESS) {
shmseg->shm_perm.mode = SHMSEG_FREE;
shm_last_free = segnum;
free((caddr_t)shm_handle, M_SHM);
/* Just in case. */
wakeup((caddr_t)shmseg);
return ENOMEM;
}
shm_handle->shm_object =
vm_object_allocate(OBJT_DEFAULT, round_page(size)/PAGE_SIZE);
shmseg->shm_internal = shm_handle;
shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid;
shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid;
@ -601,11 +601,6 @@ shminit(dummy)
void *dummy;
{
int i;
vm_offset_t garbage1, garbage2;
/* actually this *should* be pageable. SHM_{LOCK,UNLOCK} */
sysvshm_map = kmem_suballoc(kernel_map, &garbage1, &garbage2,
shminfo.shmall * PAGE_SIZE, TRUE);
for (i = 0; i < shminfo.shmmni; i++) {
shmsegs[i].shm_perm.mode = SHMSEG_FREE;
shmsegs[i].shm_perm.seq = 0;