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| author | Frans Kaashoek <[email protected]> | 2022-08-12 13:22:10 -0400 |
|---|---|---|
| committer | Frans Kaashoek <[email protected]> | 2022-08-12 13:22:10 -0400 |
| commit | 899cc02660232092209a5db57b326ab7b49813dd (patch) | |
| tree | abde95c343fb06294fba1c30036a3d6564602693 /kernel/vm.c | |
| parent | 8f58cc7df99e9f697ca3843886802ecab5cb8991 (diff) | |
| download | xv6-labs-899cc02660232092209a5db57b326ab7b49813dd.tar.gz xv6-labs-899cc02660232092209a5db57b326ab7b49813dd.tar.bz2 xv6-labs-899cc02660232092209a5db57b326ab7b49813dd.zip | |
Experiment with being more precise setting permissions for user pages.
Growing adds R|W pages (without X). Exec() marks the stack only R|W.
Probably could setup permissions for text and data better if we call
ld with --no-omagic instead of -N.
Diffstat (limited to 'kernel/vm.c')
| -rw-r--r-- | kernel/vm.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/vm.c b/kernel/vm.c index 3c6f295..284b72d 100644 --- a/kernel/vm.c +++ b/kernel/vm.c @@ -218,7 +218,7 @@ uvmfirst(pagetable_t pagetable, uchar *src, uint sz) // Allocate PTEs and physical memory to grow process from oldsz to // newsz, which need not be page aligned. Returns new size or 0 on error. uint64 -uvmalloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz) +uvmalloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz, int xperm) { char *mem; uint64 a; @@ -234,7 +234,7 @@ uvmalloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz) return 0; } memset(mem, 0, PGSIZE); - if(mappages(pagetable, a, PGSIZE, (uint64)mem, PTE_W|PTE_X|PTE_R|PTE_U) != 0){ + if(mappages(pagetable, a, PGSIZE, (uint64)mem, PTE_R|PTE_U|xperm) != 0){ kfree(mem); uvmdealloc(pagetable, a, oldsz); return 0; |