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| author | Frans Kaashoek <[email protected]> | 2019-07-22 15:38:08 -0400 |
|---|---|---|
| committer | Frans Kaashoek <[email protected]> | 2019-07-22 15:38:08 -0400 |
| commit | b2e9c8eea5d4f4edb43ae7be9e15986dbfce5b95 (patch) | |
| tree | 22f78e4caee4b4481d30a1b83acd13b84841a06e /kernel/exec.c | |
| parent | 38b430687cc248d7d2928e3b7cedf9d220b96013 (diff) | |
| download | xv6-labs-b2e9c8eea5d4f4edb43ae7be9e15986dbfce5b95.tar.gz xv6-labs-b2e9c8eea5d4f4edb43ae7be9e15986dbfce5b95.tar.bz2 xv6-labs-b2e9c8eea5d4f4edb43ae7be9e15986dbfce5b95.zip | |
Clear U bit for second stack page so that it functions as a guard page
Diffstat (limited to 'kernel/exec.c')
| -rw-r--r-- | kernel/exec.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/exec.c b/kernel/exec.c index b21afbb..c25dfb0 100644 --- a/kernel/exec.c +++ b/kernel/exec.c @@ -68,6 +68,7 @@ exec(char *path, char **argv) sz = PGROUNDUP(sz); if((sz = uvmalloc(pagetable, sz, sz + 2*PGSIZE)) == 0) goto bad; + clearpteu(pagetable, sz-2*PGSIZE); sp = sz; stackbase = sp - PGSIZE; |