exec.c: Fix off-by-one error in register_subpage

subpage_register() expects "end" to be the last byte in the mapping.
Registering a non-page-aligned memory region that extends up to or
beyond a page boundary causes subpage_register() to silently fail
through the (end >= PAGE_SIZE) check.

This bug does not cause noticeable problems for mappings that do not
extend to a page boundary, though they do register an extra byte.

Signed-off-by: Tyler Hall <tylerwhall@gmail.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
This commit is contained in:
Tyler Hall 2012-07-25 18:45:03 -04:00 committed by Stefan Hajnoczi
parent 8715fc1e4c
commit adb2a9b5d4

2
exec.c
View File

@ -2271,7 +2271,7 @@ static void register_subpage(MemoryRegionSection *section)
subpage = container_of(existing->mr, subpage_t, iomem);
}
start = section->offset_within_address_space & ~TARGET_PAGE_MASK;
end = start + section->size;
end = start + section->size - 1;
subpage_register(subpage, start, end, phys_section_add(section));
}