From: Tyler Hall <[email protected]> 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 <[email protected]> Reviewed-by: Peter Maydell <[email protected]> Reviewed-by: Avi Kivity <[email protected]> Signed-off-by: Stefan Hajnoczi <[email protected]> --- exec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/exec.c b/exec.c index feb4795..27b100c 100644 --- a/exec.c +++ b/exec.c @@ -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)); } -- 1.7.10.4
