From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1791) id 153F6384800F; Mon, 1 Mar 2021 17:35:27 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 153F6384800F Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: Adhemerval Zanella To: glibc-cvs@sourceware.org Subject: [glibc/azanella/y2038] linux: Add recvvmsg fallback for 64-bit time_t SO_TIMESTAMP{NS} X-Act-Checkin: glibc X-Git-Author: Adhemerval Zanella X-Git-Refname: refs/heads/azanella/y2038 X-Git-Oldrev: 65fe20db90da9da7c9cc710467e7941ca1059bbe X-Git-Newrev: 0e76aa956f99d7d766c60a2035a4954496e677f1 Message-Id: <20210301173527.153F6384800F@sourceware.org> Date: Mon, 1 Mar 2021 17:35:27 +0000 (GMT) X-BeenThere: glibc-cvs@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Glibc-cvs mailing list List-Unsubscribe: , List-Archive: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Mar 2021 17:35:27 -0000 https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=0e76aa956f99d7d766c60a2035a4954496e677f1 commit 0e76aa956f99d7d766c60a2035a4954496e677f1 Author: Adhemerval Zanella Date: Tue Sep 8 09:08:10 2020 -0300 linux: Add recvvmsg fallback for 64-bit time_t SO_TIMESTAMP{NS} Handle the SO_TIMESTAMP{NS} similar to recvmsg: for !__ASSUME_TIME64_SYSCALLS it converts the first 32-bit time SO_TIMESTAMP or SO_TIMESTAMPNS and appends it to the control buffer if has extra space or returns MSG_CTRUNC otherwise. The 32-bit time field is kept as-is. Also for !__ASSUME_TIME64_SYSCALLS it limits the maximum number of 'struct mmsghdr *' to IOV_MAX (and also increases the stack size requirement to IOV_MAX times sizeof (socklen_t)). The Linux imposes a similar limit to sendmmsg, so bound the array size on recvmmsg is not unreasonable. And this will be used only on older when building with 32-bit time support. Checked on x86_64-linux-gnu and i686-linux-gnu (on 5.4 and on 4.15 kernel). Diff: --- sysdeps/unix/sysv/linux/recvmmsg.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/sysdeps/unix/sysv/linux/recvmmsg.c b/sysdeps/unix/sysv/linux/recvmmsg.c index 672ba20332..5cd107ffa9 100644 --- a/sysdeps/unix/sysv/linux/recvmmsg.c +++ b/sysdeps/unix/sysv/linux/recvmmsg.c @@ -44,13 +44,26 @@ __recvmmsg64 (int fd, struct mmsghdr *vmessages, unsigned int vlen, int flags, ts32 = valid_timespec64_to_timespec (*timeout); pts32 = &ts32; } + + socklen_t csize[IOV_MAX]; + if (vlen > IOV_MAX) + vlen = IOV_MAX; + for (int i = 0; i < vlen; i++) + csize[i] = vmessages[i].msg_hdr.msg_controllen; + # ifdef __ASSUME_RECVMMSG_SYSCALL r = SYSCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, pts32); # else r = SOCKETCALL_CANCEL (recvmmsg, fd, vmessages, vlen, flags, pts32); # endif - if (r >= 0 && timeout != NULL) - *timeout = valid_timespec_to_timespec64 (ts32); + if (r >= 0) + { + if (timeout != NULL) + *timeout = valid_timespec_to_timespec64 (ts32); + + for (int i=0; i < r; i++) + __convert_scm_timestamps (&vmessages[i].msg_hdr, csize[i]); + } #endif /* __ASSUME_TIME64_SYSCALLS */ return r; }