On 9/8/17 10:56 AM, Ian Lepore wrote: > On Fri, 2017-09-08 at 08:14 -0400, John Baldwin wrote: >> On 9/7/17 12:29 AM, Maxim Sobolev wrote: >>> >>> Author: sobomax >>> Date: Thu Sep 7 04:29:57 2017 >>> New Revision: 323254 >>> URL: https://svnweb.freebsd.org/changeset/base/323254 >>> >>> Log: >>> In the recvmsg32() system call iterate over returned structure(s) >>> and convert any messages of types SCM_BINTIME, SCM_TIMESTAMP, >>> SCM_REALTIME and SCM_MONOTONIC from 64-bit to its 32-bit >>> representation. Otherwise we either run out of user-supplied >>> buffer to copy those out resulting in the MSG_CTRUNC or simply >>> return values that the userland 32-bit code is not going >>> to parse correctly. This fixes at least two regression tests >>> failing to function properly in 32-bit compat mode: >>> >>> tools/regression/sockets/udp_pingpong >>> tools/regression/sockets/unix_cmsg >>> >>> PR: kern/222039 >>> MFC after: 30 days >> Is this correct on !amd64? Other 32-bit platforms use a 64-bit time_t >> (note the time32_t type defined earlier in freebsd32.h). struct bintime32 >> should use time32_t for the seconds field, not uint32_t. I think that >> will be sufficient to make this correct on !amd64 (it also means that >> bintime32 == bintime on !amd64 so you could perhaps use a simpler BT_CP >> for !amd64, but the existing one is probably ok). >> > > The existing one now does *(uint64_t *) on a value that's only aligned > to a 32-bit boundary. That will work in practice because only i386 has > a 32-bit time_t that will use this code, and it's not a strict- > alignment platform. It may still cause compiler warnings about > alignment.
Mmmm, the code is used on ppc and mips as well (and mips will fault for unaligned access at least). However, once bintime32 is fixed to use time32_t I think the fraction will be 64-bit aligned? I would be fine with BT_CP() being an #ifdef though that just uses "(dst) = (src)" for !amd64. -- John Baldwin _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
