From 3752a0364883ed00100cc537832c434de3f77931 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 20 Jun 2013 15:18:04 +0100 Subject: exec.c: address_space_translate: handle access to addr 0 of 2^64 sized region The memory API allows a MemoryRegion's size to be 2^64, as a special case (otherwise the size always fits in a 64 bit integer). This meant that attempts to access address zero in a 2^64 sized region would assert in address_space_translate(): #3 0x00007ffff3e4d192 in __GI___assert_fail#(assertion=0x555555a43f32 "!a.hi", file=0x555555a43ef0 "include/qemu/int128.h", line=18, function=0x555555a4439f "int128_get64") at assert.c:103 #4 0x0000555555877642 in int128_get64 (a=...) at include/qemu/int128.h:18 #5 0x00005555558782f2 in address_space_translate (as=0x55555668d140, /addr=0, xlat=0x7fffafac9918, plen=0x7fffafac9920, is_write=false) at exec.c:221 Fix this by doing the 'min' operation in 128 bit arithmetic rather than 64 bit arithmetic (we know the result of the 'min' definitely fits in 64 bits because one of the inputs did). Signed-off-by: Peter Maydell Signed-off-by: Paolo Bonzini --- exec.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'exec.c') diff --git a/exec.c b/exec.c index 5b8b40d090..eb200d0ffc 100644 --- a/exec.c +++ b/exec.c @@ -218,7 +218,7 @@ MemoryRegionSection *address_space_translate(AddressSpace *as, hwaddr addr, *xlat = addr + section->offset_within_region; diff = int128_sub(section->mr->size, int128_make64(addr)); - *plen = MIN(int128_get64(diff), *plen); + *plen = int128_get64(int128_min(diff, int128_make64(*plen))); return section; } #endif -- cgit v1.2.3