From 28146206578ebe1b84b48e6f255738a227058c04 Mon Sep 17 00:00:00 2001 From: Artem Khramov Date: Thu, 15 Aug 2019 03:21:48 +0600 Subject: bpo-37811: FreeBSD, OSX: fix poll(2) usage in sockets module (GH-15202) FreeBSD implementation of poll(2) restricts the timeout argument to be either zero, or positive, or equal to INFTIM (-1). Unless otherwise overridden, socket timeout defaults to -1. This value is then converted to milliseconds (-1000) and used as argument to the poll syscall. poll returns EINVAL (22), and the connection fails. This bug was discovered during the EINTR handling testing, and the reproduction code can be found in https://bugs.python.org/issue23618 (see connect_eintr.py, attached). On GNU/Linux, the example runs as expected. This change is trivial: If the supplied timeout value is negative, truncate it to -1. --- Misc/ACKS | 1 + .../next/Library/2019-08-14-21-41-07.bpo-37811.d1xYj7.rst | 4 ++++ Modules/socketmodule.c | 11 +++++++++++ 3 files changed, 16 insertions(+) create mode 100644 Misc/NEWS.d/next/Library/2019-08-14-21-41-07.bpo-37811.d1xYj7.rst diff --git a/Misc/ACKS b/Misc/ACKS index 3b4cf85..52a5d70 100644 --- a/Misc/ACKS +++ b/Misc/ACKS @@ -837,6 +837,7 @@ Lawrence Kesteloot Garvit Khatri Vivek Khera Dhiru Kholia +Artem Khramov Akshit Khurana Sanyam Khurana Mads Kiilerich diff --git a/Misc/NEWS.d/next/Library/2019-08-14-21-41-07.bpo-37811.d1xYj7.rst b/Misc/NEWS.d/next/Library/2019-08-14-21-41-07.bpo-37811.d1xYj7.rst new file mode 100644 index 0000000..662e7dc --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-08-14-21-41-07.bpo-37811.d1xYj7.rst @@ -0,0 +1,4 @@ +Fix ``socket`` module's ``socket.connect(address)`` function being unable to +establish connection in case of interrupted system call. The problem was +observed on all OSes which ``poll(2)`` system call can take only +non-negative integers and -1 as a timeout value. diff --git a/Modules/socketmodule.c b/Modules/socketmodule.c index f220c26..d4f2098 100755 --- a/Modules/socketmodule.c +++ b/Modules/socketmodule.c @@ -789,6 +789,17 @@ internal_select(PySocketSockObject *s, int writing, _PyTime_t interval, ms = _PyTime_AsMilliseconds(interval, _PyTime_ROUND_CEILING); assert(ms <= INT_MAX); + /* On some OSes, typically BSD-based ones, the timeout parameter of the + poll() syscall, when negative, must be exactly INFTIM, where defined, + or -1. See issue 37811. */ + if (ms < 0) { +#ifdef INFTIM + ms = INFTIM; +#else + ms = -1; +#endif + } + Py_BEGIN_ALLOW_THREADS; n = poll(&pollfd, 1, (int)ms); Py_END_ALLOW_THREADS; -- cgit v0.12