minix/servers/vm/exit.c
Ben Gras 040362e379 exec() cleanup, generalization, improvement
. make exec() callers (i.e. vfs and rs) determine the
	  memory layout by explicitly reserving regions using
	  mmap() calls on behalf of the exec()ing process,
	  i.e. handling all of the exec logic, thereby eliminating
	  all special exec() knowledge from VM.
	. the new procedure is: clear the exec()ing process
	  first, then call third-party mmap()s to reserve memory, then
	  copy the executable file section contents in, all using callbacks
	  tailored to the caller's way of starting an executable
	. i.e. no more explicit EXEC_NEWMEM-style calls in PM or VM
	  as with rigid 2-section arguments
	. this naturally allows generalizing exec() by simply loading
	  all ELF sections
	. drop/merge of lots of duplicate exec() code into libexec
	. not copying the code sections to vfs and into the executable
	  again is a measurable performance improvement (about 3.3% faster
	  for 'make' in src/servers/)
2012-06-07 15:15:01 +02:00

148 lines
3.2 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);
vmp->vm_heap = NULL;
if(vmp->vm_flags & VMF_HASPT) {
vmp->vm_flags &= ~VMF_HASPT;
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_heap = NULL;
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;
}
if(vmp->vm_flags & VMF_HAS_DMA) {
release_dma(vmp);
} else if(vmp->vm_flags & VMF_HASPT) {
/* Free pagetable and pages allocated by pt code. */
SANITYCHECK(SCL_DETAIL);
free_proc(vmp);
SANITYCHECK(SCL_DETAIL);
} else {
/* Free the data and stack segments. */
free_mem(vmp->vm_arch.vm_seg[D].mem_phys,
vmp->vm_arch.vm_seg[S].mem_vir +
vmp->vm_arch.vm_seg[S].mem_len -
vmp->vm_arch.vm_seg[D].mem_vir);
}
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);
pt_new(&vmp->vm_pt);
vmp->vm_flags |= VMF_HASPT;
pt_bind(&vmp->vm_pt, vmp);
regular_segs(vmp);
return OK;
default:
return EINVAL;
}
return OK;
}