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| author | Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it> | 2005-09-10 19:44:57 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-10 12:00:18 -0700 |
| commit | d129f31236c241c07e583e8bc695c382365d02ce (patch) | |
| tree | 53e6370fe8e3134f41d8b0c08d9af400ab9504eb /arch/um/kernel | |
| parent | d99c4022f60a9aa3a8dc6b7d71f3d0998c696912 (diff) | |
| download | blackbird-op-linux-d129f31236c241c07e583e8bc695c382365d02ce.tar.gz blackbird-op-linux-d129f31236c241c07e583e8bc695c382365d02ce.zip | |
[PATCH] uml: fix fault handler on write
The UML fault handler was recently changed to enforce PROT_NONE protections,
by requiring VM_READ or VM_EXEC on VMA's.
However, by mistake, things were changed such that VM_READ is always checked,
also on write faults; so a VMA mapped with only PROT_WRITE is not readable
(unless it's prefaulted with MAP_POPULATE or with a write), which is different
from i386.
Discovered while testing remap_file_pages protection support.
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/um/kernel')
| -rw-r--r-- | arch/um/kernel/trap_kern.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/um/kernel/trap_kern.c b/arch/um/kernel/trap_kern.c index b5fc89fe9eab..d20361dcd127 100644 --- a/arch/um/kernel/trap_kern.c +++ b/arch/um/kernel/trap_kern.c @@ -57,7 +57,8 @@ good_area: if(is_write && !(vma->vm_flags & VM_WRITE)) goto out; - if(!(vma->vm_flags & (VM_READ | VM_EXEC))) + /* Don't require VM_READ|VM_EXEC for write faults! */ + if(!is_write && !(vma->vm_flags & (VM_READ | VM_EXEC))) goto out; do { |
