Commit d129f312 authored Sep 10, 2005 by Paolo 'Blaisorblade' Giarrusso Committed by Linus Torvalds Sep 10, 2005

[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>

parent d99c4022

arch/um/kernel/trap_kern.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -57,7 +57,8 @@ int handle_page_fault(unsigned long address, unsigned long ip,
		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 {