From e1a37303c89696a110c61a156768ea15cc03a246 Mon Sep 17 00:00:00 2001
From: Robert Morris <rtm@csail.mit.edu>
Date: Fri, 20 Sep 2019 12:13:57 -0400
Subject: yet another sbrk() bug fix, and usertest
---
kernel/vm.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
(limited to 'kernel/vm.c')
diff --git a/kernel/vm.c b/kernel/vm.c
index 8036be7..c5da0c1 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -270,7 +270,8 @@ uvmdealloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz)
return oldsz;
uint64 newup = PGROUNDUP(newsz);
- uvmunmap(pagetable, newup, oldsz - newup, 1);
+ if(newup < PGROUNDUP(oldsz))
+ uvmunmap(pagetable, newup, oldsz - newup, 1);
return newsz;
}
--
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