make grade 140/140

kernel/proc.c

@@ -345,6 +345,7 @@ fork(void)
       newvma->prot = p->map_region[i]->prot;
       newvma->length = p->map_region[i]->length;
       newvma->flag = p->map_region[i]->flag;
+      newvma->offset = p->map_region[i]->offset;
       release(&lock_vma_pool);
       np->map_region[i] = newvma;
     }
@@ -756,6 +757,7 @@ uint64 do_mmap(struct proc* p, int length, int prot, int flags, int fd)
   newvma->prot = prot;
   newvma->length = length;
   newvma->flag = flags;
+  newvma->offset = 0;
   release(&lock_vma_pool);
 
   filedup(newvma->f);
@@ -800,6 +802,7 @@ uint64 do_munmap(uint64 addr, int length)
     }
   }
   if (vma0 == 0) {
+    printf("failed to ummap %p\n", addr);
     return -1;
   }
   // remove all relavant pages
@@ -809,16 +812,19 @@ uint64 do_munmap(uint64 addr, int length)
   uint64 free_start = MAX(PGROUNDDOWN(addr), vma0->addr);
   uint64 free_end = MIN(PGROUNDUP(addr + length), vma_end);
   for (uint64 va0 = free_start; va0 < free_end; va0 += PGSIZE) {
+    if (walkaddr(p->pagetable, va0)){
       if (vma0->flag == MAP_SHARED) {
         begin_op();
         ilock(vma0->f->ip);
-      writei(vma0->f->ip, 1, va0, va0 - addr, PGSIZE); // ? no sure if to write whole page
+        // int wrsz = 
+        writei(vma0->f->ip, 1, va0, va0 + vma0->offset - vma0->addr, PGSIZE); // ? no sure if to write whole page
+        // printf("Write %d bytes from %p @offset=%d(off=%x,addr=%x)\n", wrsz, va0, va0 + vma0->offset - vma0->addr, vma0->offset, vma0->addr);
         iunlock(vma0->f->ip);
         end_op();
       }
-    if (walkaddr(p->pagetable, va0))
       uvmunmap(p->pagetable, va0, 1, 1);
     }
+  }
   if (free_start <= vma0->addr && free_end >= vma_end) {
       // all released
       fileclose(vma0->f);
@@ -828,6 +834,7 @@ uint64 do_munmap(uint64 addr, int length)
     vma0->length = free_start - vma0->addr;
   } else if (free_start <= vma0->addr) {
     vma0->length -= free_end - vma0->addr;
+    vma0->offset += free_end - vma0->addr;
     vma0->addr = free_end;
   } else {
     panic("unsupported unmap type");

kernel/proc.h

@@ -86,6 +86,7 @@ struct vma {
   uint length;
   uint prot;
   uint flag;
+  uint offset;
   struct file* f;
 };
 

kernel/trap.c

@@ -72,7 +72,6 @@ usertrap(void)
   } else if(r_scause() == 13){
     int va0 = r_stval();
     struct vma* vma0 = 0;
-    if (va0 < MMAP_START) panic("unknown page fault");
     for (int i = 0; i < NMAXVMA; ++ i) {
       if(p->map_region[i]
           && p->map_region[i]->addr <= va0
@@ -81,6 +80,9 @@ usertrap(void)
         break;
       }
     }
+    if (vma0 == 0) {
+      goto bad;
+    }
     uint64 phy_addr = (uint64)kalloc();
     uint pgflag = PTE_U | (vma0->prot << 1); 
     // save some code... there is PTE_R/W/X = PROT_READ/WRITE/EXEC << 1
@@ -88,12 +90,15 @@ usertrap(void)
     memset((void*)phy_addr, 0, PGSIZE);
     begin_op();
     ilock(vma0->f->ip);
-    readi(vma0->f->ip, 0, phy_addr, va0 - vma0->addr, PGSIZE);
+    // int rdsz = 
+    readi(vma0->f->ip, 0, phy_addr, va0 + vma0->offset - vma0->addr, PGSIZE);
+    // printf("Load %d bytes to %p @offset=%d\n", rdsz, va0,va0 + vma0->offset - vma0->addr);
     iunlock(vma0->f->ip);
     end_op();
   } else if((which_dev = devintr()) != 0){
     // ok
   } else {
+bad:
     printf("usertrap(): unexpected scause %p pid=%d\n", r_scause(), p->pid);
     printf("            sepc=%p stval=%p\n", r_sepc(), r_stval());
     setkilled(p);

time.txt

@@ -0,0 +1 @@
+6