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authorRobert Morris <[email protected]>2019-09-20 11:35:27 -0400
committerRobert Morris <[email protected]>2019-09-20 11:35:27 -0400
commit4de161f973aa06d5f08de1063d3fc9c22e4547e7 (patch)
treebf6ba51ef64ae3e255306de4de0dd609e819fbd6 /kernel/vm.c
parentca30cac702157d0d3a2c89e4436f0bff303a6e0a (diff)
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don't panic if a program frees all its memory with sbrk().
if a program sbrk()'s to a non-page-boundary, don't free that page. corresponding usertests.
Diffstat (limited to 'kernel/vm.c')
-rw-r--r--kernel/vm.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/kernel/vm.c b/kernel/vm.c
index 51165b7..8036be7 100644
--- a/kernel/vm.c
+++ b/kernel/vm.c
@@ -268,7 +268,10 @@ uvmdealloc(pagetable_t pagetable, uint64 oldsz, uint64 newsz)
{
if(newsz >= oldsz)
return oldsz;
- uvmunmap(pagetable, newsz, oldsz - newsz, 1);
+
+ uint64 newup = PGROUNDUP(newsz);
+ uvmunmap(pagetable, newup, oldsz - newup, 1);
+
return newsz;
}