minix/servers/vm/exit.c
Ben Gras b1da7fafd0 vm: fix a null dereference on out-of-memory
. also make other out-of-memory conditions less fatal
	. add a test case for a user program using all the memory
	  it can
	. remove some diagnostic prints for situations that are normal
	  when running out of memory so running the test isn't noisy
2012-11-09 18:36:51 +01:00

135 lines
2.7 KiB
C

#define _SYSTEM 1
#include <minix/callnr.h>
#include <minix/com.h>
#include <minix/config.h>
#include <minix/const.h>
#include <minix/ds.h>
#include <minix/endpoint.h>
#include <minix/keymap.h>
#include <minix/minlib.h>
#include <minix/type.h>
#include <minix/ipc.h>
#include <minix/sysutil.h>
#include <minix/syslib.h>
#include <minix/bitmap.h>
#include <errno.h>
#include <assert.h>
#include <env.h>
#include "glo.h"
#include "proto.h"
#include "util.h"
#include "sanitycheck.h"
void free_proc(struct vmproc *vmp)
{
map_free_proc(vmp);
pt_free(&vmp->vm_pt);
region_init(&vmp->vm_regions_avl);
vmp->vm_region_top = 0;
#if VMSTATS
vmp->vm_bytecopies = 0;
#endif
}
void clear_proc(struct vmproc *vmp)
{
region_init(&vmp->vm_regions_avl);
vmp->vm_region_top = 0;
vmp->vm_callback = NULL; /* No pending vfs callback. */
vmp->vm_flags = 0; /* Clear INUSE, so slot is free. */
vmp->vm_yielded = 0;
#if VMSTATS
vmp->vm_bytecopies = 0;
#endif
}
/*===========================================================================*
* do_exit *
*===========================================================================*/
int do_exit(message *msg)
{
int proc;
struct vmproc *vmp;
SANITYCHECK(SCL_FUNCTIONS);
if(vm_isokendpt(msg->VME_ENDPOINT, &proc) != OK) {
printf("VM: bogus endpoint VM_EXIT %d\n", msg->VME_ENDPOINT);
return EINVAL;
}
vmp = &vmproc[proc];
if(!(vmp->vm_flags & VMF_EXITING)) {
printf("VM: unannounced VM_EXIT %d\n", msg->VME_ENDPOINT);
return EINVAL;
}
{
/* Free pagetable and pages allocated by pt code. */
SANITYCHECK(SCL_DETAIL);
free_proc(vmp);
SANITYCHECK(SCL_DETAIL);
}
SANITYCHECK(SCL_DETAIL);
/* Reset process slot fields. */
clear_proc(vmp);
SANITYCHECK(SCL_FUNCTIONS);
return OK;
}
/*===========================================================================*
* do_willexit *
*===========================================================================*/
int do_willexit(message *msg)
{
int proc;
struct vmproc *vmp;
if(vm_isokendpt(msg->VMWE_ENDPOINT, &proc) != OK) {
printf("VM: bogus endpoint VM_EXITING %d\n",
msg->VMWE_ENDPOINT);
return EINVAL;
}
vmp = &vmproc[proc];
vmp->vm_flags |= VMF_EXITING;
return OK;
}
int do_procctl(message *msg)
{
endpoint_t proc;
struct vmproc *vmp;
if(vm_isokendpt(msg->VMPCTL_WHO, &proc) != OK) {
printf("VM: bogus endpoint VM_PROCCTL %d\n",
msg->VMPCTL_WHO);
return EINVAL;
}
vmp = &vmproc[proc];
switch(msg->VMPCTL_PARAM) {
case VMPPARAM_CLEAR:
if(msg->m_source != RS_PROC_NR
&& msg->m_source != VFS_PROC_NR)
return EPERM;
free_proc(vmp);
if(pt_new(&vmp->vm_pt) != OK)
panic("VMPPARAM_CLEAR: pt_new failed");
pt_bind(&vmp->vm_pt, vmp);
return OK;
default:
return EINVAL;
}
return OK;
}