299 lines
7.2 KiB
C
299 lines
7.2 KiB
C
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#define _SYSTEM 1
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#include <minix/callnr.h>
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#include <minix/com.h>
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#include <minix/config.h>
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#include <minix/const.h>
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#include <minix/ds.h>
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#include <minix/endpoint.h>
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#include <minix/keymap.h>
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#include <minix/minlib.h>
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#include <minix/type.h>
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#include <minix/ipc.h>
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#include <minix/sysutil.h>
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#include <minix/syslib.h>
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#include <minix/safecopies.h>
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#include <minix/bitmap.h>
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#include <errno.h>
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#include <string.h>
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#include <env.h>
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#include <stdio.h>
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#include <fcntl.h>
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#include <signal.h>
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#include <assert.h>
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#include "glo.h"
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#include "proto.h"
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#include "util.h"
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#include "region.h"
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/*===========================================================================*
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* pf_errstr *
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*===========================================================================*/
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char *pf_errstr(u32_t err)
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{
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static char buf[100];
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sprintf(buf, "err 0x%lx ", (long)err);
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if(PFERR_NOPAGE(err)) strcat(buf, "nopage ");
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if(PFERR_PROT(err)) strcat(buf, "protection ");
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if(PFERR_WRITE(err)) strcat(buf, "write");
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if(PFERR_READ(err)) strcat(buf, "read");
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return buf;
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}
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struct pf_state {
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endpoint_t ep;
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vir_bytes vaddr;
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u32_t err;
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};
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struct hm_state {
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endpoint_t requestor;
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struct vmproc *vmp;
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vir_bytes mem;
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vir_bytes len;
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int wrflag;
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};
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static void pf_cont(struct vmproc *vmp, message *m, void *arg, void *statearg);
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static void hm_cont(struct vmproc *vmp, message *m, void *arg, void *statearg);
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static void handle_pagefault(endpoint_t ep, vir_bytes addr, u32_t err, int retry)
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{
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struct vmproc *vmp;
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int s, result;
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struct vir_region *region;
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vir_bytes offset;
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int p, wr = PFERR_WRITE(err);
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int io = 0;
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if(vm_isokendpt(ep, &p) != OK)
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panic("handle_pagefault: endpoint wrong: %d", ep);
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vmp = &vmproc[p];
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assert(vmp->vm_flags & VMF_INUSE);
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/* See if address is valid at all. */
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if(!(region = map_lookup(vmp, addr, NULL))) {
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if(PFERR_PROT(err)) {
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printf("VM: pagefault: SIGSEGV %d protected addr 0x%lx; %s\n",
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ep, addr, pf_errstr(err));
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} else {
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assert(PFERR_NOPAGE(err));
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printf("VM: pagefault: SIGSEGV %d bad addr 0x%lx; %s\n",
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ep, addr, pf_errstr(err));
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sys_sysctl_stacktrace(ep);
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}
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if((s=sys_kill(vmp->vm_endpoint, SIGSEGV)) != OK)
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panic("sys_kill failed: %d", s);
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if((s=sys_vmctl(ep, VMCTL_CLEAR_PAGEFAULT, 0 /*unused*/)) != OK)
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panic("do_pagefaults: sys_vmctl failed: %d", ep);
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return;
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}
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/* If process was writing, see if it's writable. */
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if(!(region->flags & VR_WRITABLE) && wr) {
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printf("VM: pagefault: SIGSEGV %d ro map 0x%lx %s\n",
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ep, addr, pf_errstr(err));
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if((s=sys_kill(vmp->vm_endpoint, SIGSEGV)) != OK)
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panic("sys_kill failed: %d", s);
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if((s=sys_vmctl(ep, VMCTL_CLEAR_PAGEFAULT, 0 /*unused*/)) != OK)
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panic("do_pagefaults: sys_vmctl failed: %d", ep);
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return;
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}
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assert(addr >= region->vaddr);
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offset = addr - region->vaddr;
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/* Access is allowed; handle it. */
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if(retry) {
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result = map_pf(vmp, region, offset, wr, NULL, NULL, 0, &io);
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assert(result != SUSPEND);
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} else {
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struct pf_state state;
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state.ep = ep;
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state.vaddr = addr;
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state.err = err;
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result = map_pf(vmp, region, offset, wr, pf_cont,
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&state, sizeof(state), &io);
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}
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if (io)
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vmp->vm_major_page_fault++;
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else
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vmp->vm_minor_page_fault++;
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if(result == SUSPEND) {
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return;
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}
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if(result != OK) {
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printf("VM: pagefault: SIGSEGV %d pagefault not handled\n", ep);
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if((s=sys_kill(ep, SIGSEGV)) != OK)
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panic("sys_kill failed: %d", s);
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if((s=sys_vmctl(ep, VMCTL_CLEAR_PAGEFAULT, 0 /*unused*/)) != OK)
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panic("do_pagefaults: sys_vmctl failed: %d", ep);
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return;
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}
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pt_clearmapcache();
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/* Pagefault is handled, so now reactivate the process. */
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if((s=sys_vmctl(ep, VMCTL_CLEAR_PAGEFAULT, 0 /*unused*/)) != OK)
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panic("do_pagefaults: sys_vmctl failed: %d", ep);
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}
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static void pf_cont(struct vmproc *vmp, message *m,
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void *arg, void *statearg)
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{
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struct pf_state *state = statearg;
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int p;
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if(vm_isokendpt(state->ep, &p) != OK) return; /* signal */
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handle_pagefault(state->ep, state->vaddr, state->err, 1);
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}
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static void hm_cont(struct vmproc *vmp, message *m,
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void *arg, void *statearg)
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{
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int r;
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struct hm_state *state = statearg;
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printf("hm_cont: result %d\n", m->VMV_RESULT);
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r = handle_memory(vmp, state->mem, state->len, state->wrflag,
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hm_cont, &state, sizeof(state));
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if(r == SUSPEND) {
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printf("VM: hm_cont: damnit: hm_cont: more SUSPEND\n");
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return;
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}
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printf("VM: hm_cont: ok, result %d, requestor %d\n", r, state->requestor);
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if(sys_vmctl(state->requestor, VMCTL_MEMREQ_REPLY, r) != OK)
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panic("hm_cont: sys_vmctl failed: %d", r);
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printf("MEMREQ_REPLY sent\n");
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}
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/*===========================================================================*
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* do_pagefaults *
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*===========================================================================*/
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void do_pagefaults(message *m)
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{
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handle_pagefault(m->m_source, m->VPF_ADDR, m->VPF_FLAGS, 0);
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}
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/*===========================================================================*
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* do_memory *
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*===========================================================================*/
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void do_memory(void)
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{
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endpoint_t who, who_s, requestor;
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vir_bytes mem, mem_s;
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vir_bytes len;
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int wrflag;
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while(1) {
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int p, r = OK;
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struct vmproc *vmp;
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r = sys_vmctl_get_memreq(&who, &mem, &len, &wrflag, &who_s,
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&mem_s, &requestor);
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switch(r) {
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case VMPTYPE_CHECK:
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{
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struct hm_state state;
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if(vm_isokendpt(who, &p) != OK)
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panic("do_memory: bad endpoint: %d", who);
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vmp = &vmproc[p];
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state.vmp = vmp;
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state.mem = mem;
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state.len = len;
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state.wrflag = wrflag;
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state.requestor = requestor;
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r = handle_memory(vmp, mem, len,
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wrflag, hm_cont, &state, sizeof(state));
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break;
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}
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default:
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return;
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}
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if(r != SUSPEND) {
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if(sys_vmctl(requestor, VMCTL_MEMREQ_REPLY, r) != OK)
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panic("do_memory: sys_vmctl failed: %d", r);
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}
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}
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}
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int handle_memory(struct vmproc *vmp, vir_bytes mem, vir_bytes len, int wrflag,
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vfs_callback_t callback, void *state, int statelen)
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{
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struct vir_region *region;
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vir_bytes o;
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struct hm_state *hmstate = (struct hm_state *) state;
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/* Page-align memory and length. */
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o = mem % VM_PAGE_SIZE;
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mem -= o;
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len += o;
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o = len % VM_PAGE_SIZE;
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if(o > 0) len += VM_PAGE_SIZE - o;
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while(len > 0) {
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int r;
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if(!(region = map_lookup(vmp, mem, NULL))) {
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#if VERBOSE
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map_printmap(vmp);
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printf("VM: do_memory: memory doesn't exist\n");
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#endif
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r = EFAULT;
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} else if(!(region->flags & VR_WRITABLE) && wrflag) {
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#if VERBOSE
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printf("VM: do_memory: write to unwritable map\n");
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#endif
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r = EFAULT;
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} else {
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vir_bytes offset, sublen;
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assert(region->vaddr <= mem);
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assert(!(region->vaddr % VM_PAGE_SIZE));
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offset = mem - region->vaddr;
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sublen = len;
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if(offset + sublen > region->length)
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sublen = region->length - offset;
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if(hmstate && hmstate->requestor == VFS_PROC_NR
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&& region->def_memtype == &mem_type_mappedfile) {
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r = map_handle_memory(vmp, region, offset,
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sublen, wrflag, NULL, NULL, 0);
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} else {
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r = map_handle_memory(vmp, region, offset,
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sublen, wrflag, callback, state, sizeof(state));
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}
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len -= sublen;
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mem += sublen;
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}
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if(r != OK) {
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#if VERBOSE
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printf("VM: memory range 0x%lx-0x%lx not available in %d\n",
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mem, mem+len, vmp->vm_endpoint);
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#endif
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return r;
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}
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}
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return OK;
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}
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