From ddb1b65d61ec6ad45e10b11aa707a0a896ed5d2e Mon Sep 17 00:00:00 2001
From: Philippe Pittoli <karchnu@karchnu.fr>
Date: Fri, 14 Feb 2025 08:05:35 +0100
Subject: [PATCH] Minor comments.
---
kernel/proc.c | 2 +-
kernel/vm.c | 4 ++--
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/proc.c b/kernel/proc.c
index 130d9ce..3b036b3 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -38,7 +38,7 @@ proc_mapstacks(pagetable_t kpgtbl)
char *pa = kalloc();
if(pa == 0)
panic("kalloc");
- uint64 va = KSTACK((int) (p - proc));
+ uint64 va = KSTACK((int) (p - proc)); // p-proc = to get an index (0 to 7)
kvmmap(kpgtbl, va, (uint64)pa, PGSIZE, PTE_R | PTE_W);
}
}
diff --git a/kernel/vm.c b/kernel/vm.c
index 62421a2..9849645 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -158,9 +158,9 @@ mappages(pagetable_t pagetable, uint64 va, uint64 size, uint64 pa, int perm)
a = va;
last = va + size - PGSIZE;
for(;;){
- if((pte = walk(pagetable, a, 1)) == 0)
+ if((pte = walk(pagetable, a, 1)) == 0) // In case the PTE hasn't been allocated.
return -1;
- if(*pte & PTE_V)
+ if(*pte & PTE_V) // In case the PTE already was allocated to someone else (it is valid).
panic("mappages: remap");
*pte = PA2PTE(pa) | perm | PTE_V;
if(a == last)