From 17745b02462bfbc0f1e8e5b2a062d887280345ea Mon Sep 17 00:00:00 2001 From: Michael Vogt Date: Tue, 28 Oct 2008 20:57:31 +0100 Subject: * apt-pkg/deb/dpkgpm.cc: - fix potential hang when in a backgroud process group --- apt-pkg/deb/dpkgpm.cc | 16 ++++++++++++---- debian/changelog | 2 ++ 2 files changed, 14 insertions(+), 4 deletions(-) diff --git a/apt-pkg/deb/dpkgpm.cc b/apt-pkg/deb/dpkgpm.cc index 85cf4e119..36c20ad85 100644 --- a/apt-pkg/deb/dpkgpm.cc +++ b/apt-pkg/deb/dpkgpm.cc @@ -587,6 +587,11 @@ static int racy_pselect(int nfds, fd_set *readfds, fd_set *writefds, */ bool pkgDPkgPM::Go(int OutStatusFd) { + fd_set rfds; + struct timespec tv; + sigset_t sigmask; + sigset_t original_sigmask; + unsigned int MaxArgs = _config->FindI("Dpkg::MaxArgs",8*1024); unsigned int MaxArgBytes = _config->FindI("Dpkg::MaxArgBytes",32*1024); bool NoTriggers = _config->FindB("DPkg::NoTriggers",false); @@ -795,7 +800,14 @@ bool pkgDPkgPM::Go(int OutStatusFd) rtt = tt; cfmakeraw(&rtt); rtt.c_lflag &= ~ECHO; + // block SIGTTOU during tcsetattr to prevent a hang if + // the process is a member of the background process group + // http://www.opengroup.org/onlinepubs/000095399/functions/tcsetattr.html + sigemptyset(&sigmask); + sigaddset(&sigmask, SIGTTOU); + sigprocmask(SIG_BLOCK,&sigmask, &original_sigmask); tcsetattr(0, TCSAFLUSH, &rtt); + sigprocmask(SIG_SETMASK, &original_sigmask, 0); } // Fork dpkg @@ -862,10 +874,6 @@ bool pkgDPkgPM::Go(int OutStatusFd) close(slave); // setups fds - fd_set rfds; - struct timespec tv; - sigset_t sigmask; - sigset_t original_sigmask; sigemptyset(&sigmask); sigprocmask(SIG_BLOCK,&sigmask,&original_sigmask); diff --git a/debian/changelog b/debian/changelog index 283c49fd5..fdf2db409 100644 --- a/debian/changelog +++ b/debian/changelog @@ -28,6 +28,8 @@ apt (0.7.17) UNRELEASED; urgency=low of variables (LP: #56792) * apt-pkg/cacheiterators.h: - add missing checks for Owner == 0 in end() + * apt-pkg/deb/dpkgpm.cc: + - fix potential hang when in a backgroud process group [ Dereck Wonnacott ] * apt-ftparchive might write corrupt Release files (LP: #46439) -- cgit v1.2.3