diff options
| -rw-r--r-- | memlayout.h | 1 | ||||
| -rw-r--r-- | vm.c | 6 |
2 files changed, 3 insertions, 4 deletions
diff --git a/memlayout.h b/memlayout.h index ad4fda2..c2879b1 100644 --- a/memlayout.h +++ b/memlayout.h @@ -6,7 +6,6 @@ // Key addresses for address space layout (see kmap in vm.c for the layout) #define KERNBASE 0xF0000000 // First kernel virtual address -#define USERTOP (KERNBASE-PGSIZE) // Highest user virtual address #define KERNLINK (KERNBASE+EXTMEM) // Address where kernel is linked #ifndef __ASSEMBLER__ @@ -99,7 +99,7 @@ mappages(pde_t *pgdir, void *va, uint size, uint pa, int perm, char* (*alloc)(vo // than its memory. // // setupkvm() and exec() set up every page table like this: -// 0..USERTOP : user memory (text, data, stack, heap), mapped to some unused phys mem +// 0..KERNBASE : user memory (text, data, stack, heap), mapped to some unused phys mem // KERNBASE..KERNBASE+EXTMEM: mapped to 0..EXTMEM (below extended memory) // KERNBASE+EXTMEM..KERNBASE+end : mapped to EXTMEM..end (mapped without write permission) // KERNBASE+end..KERBASE+PHYSTOP : mapped to end..PHYSTOP (rw data + free memory) @@ -223,7 +223,7 @@ allocuvm(pde_t *pgdir, uint oldsz, uint newsz) char *mem; uint a; - if(newsz > USERTOP) + if(newsz >= KERNBASE) return 0; if(newsz < oldsz) return oldsz; @@ -279,7 +279,7 @@ freevm(pde_t *pgdir) if(pgdir == 0) panic("freevm: no pgdir"); - deallocuvm(pgdir, USERTOP, 0); + deallocuvm(pgdir, KERNBASE, 0); for(i = 0; i < NPDENTRIES; i++){ if(pgdir[i] & PTE_P) { char * v = p2v(PTE_ADDR(pgdir[i])); |