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| author | Robert Morris <rtm@csail.mit.edu> | 2019-09-20 11:35:27 -0400 |
|---|---|---|
| committer | Robert Morris <rtm@csail.mit.edu> | 2019-09-20 11:35:27 -0400 |
| commit | 4de161f973aa06d5f08de1063d3fc9c22e4547e7 (patch) | |
| tree | bf6ba51ef64ae3e255306de4de0dd609e819fbd6 /kernel/vm.c | |
| parent | ca30cac702157d0d3a2c89e4436f0bff303a6e0a (diff) | |
| download | xv6-labs-2022-4de161f973aa06d5f08de1063d3fc9c22e4547e7.tar.xz xv6-labs-2022-4de161f973aa06d5f08de1063d3fc9c22e4547e7.zip | |
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.c | 5 |
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; } |