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authorPaolo 'Blaisorblade' Giarrusso2005-09-10 19:44:57 +0200
committerLinus Torvalds2005-09-10 12:00:18 -0700
commitd129f31236c241c07e583e8bc695c382365d02ce (patch)
tree53e6370fe8e3134f41d8b0c08d9af400ab9504eb /arch/um
parentd99c4022f60a9aa3a8dc6b7d71f3d0998c696912 (diff)
[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')
-rw-r--r--arch/um/kernel/trap_kern.c3
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 {