Il 16/08/2013 23:58, Alex Williamson ha scritto: > Since commit 23326164 we align access sizes to match the alignment of > the address, but we don't align the access size itself. This means we > let illegal access sizes (ex. 3) slip through if the address is > sufficiently aligned (ex. 4). This results in an abort which would be > easy for a guest to trigger. Account for aligning the access size.
Is it the same as this? http://lists.gnu.org/archive/html/qemu-devel/2013-07/msg05398.html (which perhaps is buggy as your v1/v2/v3 :))? Paolo > Signed-off-by: Alex Williamson <alex.william...@redhat.com> > Cc: qemu-sta...@nongnu.org > --- > > v4: KISS > v3: Highest power of 2, not lowest > v2: Remove unnecessary loop condition > > exec.c | 18 +++++++++++++----- > 1 file changed, 13 insertions(+), 5 deletions(-) > > diff --git a/exec.c b/exec.c > index 3ca9381..67a822c 100644 > --- a/exec.c > +++ b/exec.c > @@ -1924,12 +1924,20 @@ static int memory_access_size(MemoryRegion *mr, > unsigned l, hwaddr addr) > } > } > > - /* Don't attempt accesses larger than the maximum. */ > - if (l > access_size_max) { > - l = access_size_max; > + /* Don't attempt accesses larger than the maximum or unsupported sizes. > */ > + if (l >= access_size_max) { > + return access_size_max; > + } else { > + if (l >= 8) { > + return 8; > + } else if (l >= 4) { > + return 4; > + } else if (l >= 2) { > + return 2; > + } else { > + return 1; > + } > } > - > - return l; > } > > bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf, > > >
