From 74c1eba516fdb0ec1a17b16be7e76613ccba92bf Mon Sep 17 00:00:00 2001
From: asselism <asselism@mit.edu>
Date: Mon, 17 Oct 2022 16:02:54 -0400
Subject: [PATCH] Made va and size page aligned in mappages
---
kernel/vm.c | 15 +++++++++++----
1 file changed, 11 insertions(+), 4 deletions(-)
diff --git a/kernel/vm.c b/kernel/vm.c
index 486945e..5c31e87 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -136,8 +136,9 @@ kvmmap(pagetable_t kpgtbl, uint64 va, uint64 pa, uint64 sz, int perm)
}
// Create PTEs for virtual addresses starting at va that refer to
-// physical addresses starting at pa. va and size might not
-// be page-aligned. Returns 0 on success, -1 if walk() couldn't
+// physical addresses starting at pa.
+// va and size MUST be page-aligned.
+// Returns 0 on success, -1 if walk() couldn't
// allocate a needed page-table page.
int
mappages(pagetable_t pagetable, uint64 va, uint64 size, uint64 pa, int perm)
@@ -145,11 +146,17 @@ mappages(pagetable_t pagetable, uint64 va, uint64 size, uint64 pa, int perm)
uint64 a, last;
pte_t *pte;
+ if((va % PGSIZE) != 0)
+ panic("mappages: va not aligned");
+
+ if((size % PGSIZE) != 0)
+ panic("mappages: size not aligned");
+
if(size == 0)
panic("mappages: size");
- a = PGROUNDDOWN(va);
- last = PGROUNDDOWN(va + size - 1);
+ a = va;
+ last = va + size - PGSIZE;
for(;;){
if((pte = walk(pagetable, a, 1)) == 0)
return -1;