Ping? thanks -- PMM
On 26 May 2015 at 19:46, Peter Maydell <peter.mayd...@linaro.org> wrote: > This patchset fixes some problems in conversions of cmsg structures > in target_to_host_cmsg() (used in send/recvmsg handling). Specifically: > > * we required the msg->msg_controllen to declare the buffer > to have enough space for final trailing padding (we were > checking against CMSG_SPACE), whereas the kernel does not > require this, and common userspace code assumes this. > * we weren't correctly handling the fact that the SO_TIMESTAMP > payload may be larger for the target than the host > * we weren't marking the messages with MSG_CTRUNC when we did > need to truncate a message that wasn't truncated by the host, > but were instead logging a QEMU message; since truncation is > always the result of a guest giving us an insufficiently > sized buffer, we should report it to the guest as the kernel > does and don't log anything > * we weren't handling the possibility of the host having a > more restrictive alignment requirement for payload structs > > The major visible issue I wanted to fix is that glibc's "try to talk > to nscd" code that it will run on startup will receive a cmsg with a > 4 byte payload and only allocates 4 bytes for it, which was causing > us to do the wrong thing on architectures that need 8-alignment > (we dropped the cmsg and printed a diagnostic message). > > > Peter Maydell (2): > linux-user: Fix length handling in host_to_target_cmsg > linux-user: use __get_user and __put_user in cmsg conversions > > linux-user/syscall.c | 89 > ++++++++++++++++++++++++++++++++++++++++++---------- > 1 file changed, 72 insertions(+), 17 deletions(-) > > -- > 1.9.1
