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| author | Frans Kaashoek <kaashoek@26-4-190.dynamic.csail.mit.edu> | 2011-08-24 10:24:40 -0400 |
|---|---|---|
| committer | Frans Kaashoek <kaashoek@26-4-190.dynamic.csail.mit.edu> | 2011-08-24 10:24:40 -0400 |
| commit | 6f2327580fe9a5f5b093814126fe7ffc02345407 (patch) | |
| tree | f086e4708d345ad93fc7642e7426f52dbdade494 /vm.c | |
| parent | 194f8bf739d441283c56985017c4a6f1b35a99cd (diff) | |
| download | xv6-labs-6f2327580fe9a5f5b093814126fe7ffc02345407.tar.gz xv6-labs-6f2327580fe9a5f5b093814126fe7ffc02345407.tar.bz2 xv6-labs-6f2327580fe9a5f5b093814126fe7ffc02345407.zip | |
Eliminate USERTOP; no use for it.
Diffstat (limited to 'vm.c')
| -rw-r--r-- | vm.c | 6 |
1 files changed, 3 insertions, 3 deletions
@@ -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])); |