minix/kernel/system/do_vmctl.c
Tomas Hruby cca24d06d8 This patch removes the global variables who_p and who_e from the
kernel (sys task).  The main reason is that these would have to become
cpu local variables on SMP.  Once the system task is not a task but a
genuine part of the kernel there is even less reason to have these
extra variables as proc_ptr will already contain all neccessary
information. In addition converting who_e to the process pointer and
back again all the time will be avoided.

Although proc_ptr will contain all important information, accessing it
as a cpu local variable will be fairly expensive, hence the value
would be assigned to some on stack local variable. Therefore it is
better to add the 'caller' argument to the syscall handlers to pass
the value on stack anyway. It also clearly denotes on who's behalf is
the syscall being executed.

This patch also ANSIfies the syscall function headers.

Last but not least, it also fixes a potential bug in virtual_copy_f()
in case the check is disabled. So far the function in case of a
failure could possible reuse an old who_p in case this function had
not been called from the system task.

virtual_copy_f() takes the caller as a parameter too. In case the
checking is disabled, the caller must be NULL and non NULL if it is
enabled as we must be able to suspend the caller.
2010-02-03 09:04:48 +00:00

196 lines
5.4 KiB
C

/* The kernel call implemented in this file:
* m_type: SYS_VMCTL
*
* The parameters for this kernel call are:
* SVMCTL_WHO which process
* SVMCTL_PARAM set this setting (VMCTL_*)
* SVMCTL_VALUE to this value
*/
#include "../system.h"
#include "../vm.h"
#include "../debug.h"
#include <minix/type.h>
/*===========================================================================*
* do_vmctl *
*===========================================================================*/
PUBLIC int do_vmctl(struct proc * caller, message * m_ptr)
{
int proc_nr;
endpoint_t ep = m_ptr->SVMCTL_WHO;
struct proc *p, *rp, *target;
int err;
if(ep == SELF) { ep = m_ptr->m_source; }
if(!isokendpt(ep, &proc_nr)) {
kprintf("do_vmctl: unexpected endpoint %d from VM\n", ep);
return EINVAL;
}
p = proc_addr(proc_nr);
switch(m_ptr->SVMCTL_PARAM) {
case VMCTL_CLEAR_PAGEFAULT:
RTS_LOCK_UNSET(p, RTS_PAGEFAULT);
return OK;
case VMCTL_MEMREQ_GET:
/* Send VM the information about the memory request. */
if(!(rp = vmrequest))
return ESRCH;
vmassert(RTS_ISSET(rp, RTS_VMREQUEST));
#if 0
printf("kernel: vm request sent by: %s / %d about %d; 0x%lx-0x%lx, wr %d, stack: %s ",
rp->p_name, rp->p_endpoint, rp->p_vmrequest.who,
rp->p_vmrequest.start,
rp->p_vmrequest.start + rp->p_vmrequest.length,
rp->p_vmrequest.writeflag, rp->p_vmrequest.stacktrace);
printf("type %d\n", rp->p_vmrequest.type);
#endif
#if DEBUG_VMASSERT
okendpt(rp->p_vmrequest.who, &proc_nr);
target = proc_addr(proc_nr);
#if 0
if(!RTS_ISSET(target, RTS_VMREQTARGET)) {
printf("set stack: %s\n", rp->p_vmrequest.stacktrace);
minix_panic("RTS_VMREQTARGET not set for target",
NO_NUM);
}
#endif
#endif
/* Reply with request fields. */
switch(rp->p_vmrequest.req_type) {
case VMPTYPE_CHECK:
m_ptr->SVMCTL_MRG_TARGET =
rp->p_vmrequest.target;
m_ptr->SVMCTL_MRG_ADDR =
rp->p_vmrequest.params.check.start;
m_ptr->SVMCTL_MRG_LENGTH =
rp->p_vmrequest.params.check.length;
m_ptr->SVMCTL_MRG_FLAG =
rp->p_vmrequest.params.check.writeflag;
m_ptr->SVMCTL_MRG_REQUESTOR =
(void *) rp->p_endpoint;
break;
case VMPTYPE_COWMAP:
case VMPTYPE_SMAP:
case VMPTYPE_SUNMAP:
m_ptr->SVMCTL_MRG_TARGET =
rp->p_vmrequest.target;
m_ptr->SVMCTL_MRG_ADDR =
rp->p_vmrequest.params.map.vir_d;
m_ptr->SVMCTL_MRG_EP2 =
rp->p_vmrequest.params.map.ep_s;
m_ptr->SVMCTL_MRG_ADDR2 =
rp->p_vmrequest.params.map.vir_s;
m_ptr->SVMCTL_MRG_LENGTH =
rp->p_vmrequest.params.map.length;
m_ptr->SVMCTL_MRG_FLAG =
rp->p_vmrequest.params.map.writeflag;
m_ptr->SVMCTL_MRG_REQUESTOR =
(void *) rp->p_endpoint;
break;
default:
minix_panic("VMREQUEST wrong type", NO_NUM);
}
rp->p_vmrequest.vmresult = VMSUSPEND;
/* Remove from request chain. */
vmrequest = vmrequest->p_vmrequest.nextrequestor;
return rp->p_vmrequest.req_type;
case VMCTL_MEMREQ_REPLY:
vmassert(RTS_ISSET(p, RTS_VMREQUEST));
vmassert(p->p_vmrequest.vmresult == VMSUSPEND);
okendpt(p->p_vmrequest.target, &proc_nr);
target = proc_addr(proc_nr);
p->p_vmrequest.vmresult = m_ptr->SVMCTL_VALUE;
vmassert(p->p_vmrequest.vmresult != VMSUSPEND);
#if DEBUG_VMASSERT
if(p->p_vmrequest.vmresult != OK)
kprintf("SYSTEM: VM replied %d to mem request\n",
p->p_vmrequest.vmresult);
printf("memreq reply: vm request sent by: %s / %d about %d; 0x%lx-0x%lx, wr %d, stack: %s ",
p->p_name, p->p_endpoint, p->p_vmrequest.who,
p->p_vmrequest.start,
p->p_vmrequest.start + p->p_vmrequest.length,
p->p_vmrequest.writeflag, p->p_vmrequest.stacktrace);
printf("type %d\n", p->p_vmrequest.type);
#endif
vmassert(RTS_ISSET(target, RTS_VMREQTARGET));
RTS_LOCK_UNSET(target, RTS_VMREQTARGET);
switch(p->p_vmrequest.type) {
case VMSTYPE_KERNELCALL:
/* Put on restart chain. */
p->p_vmrequest.nextrestart = vmrestart;
vmrestart = p;
break;
case VMSTYPE_DELIVERMSG:
vmassert(p->p_misc_flags & MF_DELIVERMSG);
vmassert(p == target);
vmassert(RTS_ISSET(p, RTS_VMREQUEST));
RTS_LOCK_UNSET(p, RTS_VMREQUEST);
break;
case VMSTYPE_MAP:
vmassert(RTS_ISSET(p, RTS_VMREQUEST));
RTS_LOCK_UNSET(p, RTS_VMREQUEST);
break;
default:
#if DEBUG_VMASSERT
printf("suspended with stack: %s\n",
p->p_vmrequest.stacktrace);
#endif
minix_panic("strange request type",
p->p_vmrequest.type);
}
return OK;
case VMCTL_ENABLE_PAGING:
/*
* system task must not get preempted while switching to paging,
* interrupt handling is not safe
*/
lock;
if(vm_running)
minix_panic("do_vmctl: paging already enabled", NO_NUM);
vm_init(p);
if(!vm_running)
minix_panic("do_vmctl: paging enabling failed", NO_NUM);
vmassert(p->p_delivermsg_lin ==
umap_local(p, D, p->p_delivermsg_vir, sizeof(message)));
if ((err = arch_enable_paging()) != OK) {
unlock;
return err;
}
if(newmap(caller, p, (struct mem_map *) m_ptr->SVMCTL_VALUE) != OK)
minix_panic("do_vmctl: newmap failed", NO_NUM);
FIXLINMSG(p);
vmassert(p->p_delivermsg_lin);
unlock;
return OK;
case VMCTL_KERN_PHYSMAP:
{
int i = m_ptr->SVMCTL_VALUE;
return arch_phys_map(i,
(phys_bytes *) &m_ptr->SVMCTL_MAP_PHYS_ADDR,
(phys_bytes *) &m_ptr->SVMCTL_MAP_PHYS_LEN,
&m_ptr->SVMCTL_MAP_FLAGS);
}
case VMCTL_KERN_MAP_REPLY:
{
return arch_phys_map_reply(m_ptr->SVMCTL_VALUE,
(vir_bytes) m_ptr->SVMCTL_MAP_VIR_ADDR);
}
}
/* Try architecture-specific vmctls. */
return arch_do_vmctl(m_ptr, p);
}