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| author | Linus Torvalds <torvalds@osdl.org> | 2005-05-19 02:39:33 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-05-19 18:46:36 +0400 |
| commit | 49a43876b935c811cfd29d8fe998a6912a1cc5c4 (patch) | |
| tree | c7d7a187a2125518e655dfeadffd38156239ffc3 | |
| parent | 05d3794aa8bd3b2c9f7920a05003c331cdeb75c5 (diff) | |
| download | linux-49a43876b935c811cfd29d8fe998a6912a1cc5c4.tar.xz | |
[PATCH] prevent NULL mmap in topdown model
Prevent the topdown allocator from allocating mmap areas all the way
down to address zero.
We still allow a MAP_FIXED mapping of page 0 (needed for various things,
ranging from Wine and DOSEMU to people who want to allow speculative
loads off a NULL pointer).
Tested by Chris Wright.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | mm/mmap.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 01f9793591f6..63df2d698414 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1244,7 +1244,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, addr = mm->free_area_cache; /* make sure it can fit in the remaining address space */ - if (addr >= len) { + if (addr > len) { vma = find_vma(mm, addr-len); if (!vma || addr <= vma->vm_start) /* remember the address as a hint for next time */ @@ -1266,7 +1266,7 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0, /* try just below the current vma->vm_start */ addr = vma->vm_start-len; - } while (len <= vma->vm_start); + } while (len < vma->vm_start); /* * A failed mmap() very likely causes application failure, |