diff options
| -rw-r--r-- | configure.ac | 28 |
1 files changed, 23 insertions, 5 deletions
diff --git a/configure.ac b/configure.ac index eb2872c6..17fb1e60 100644 --- a/configure.ac +++ b/configure.ac @@ -3518,10 +3518,11 @@ AC_ARG_WITH([sandbox], ] ) -# Some platforms (seems to be the ones that have a kernel poll(2)-type -# function with which they implement select(2)) use an extra file descriptor -# when calling select(2), which means we can't use the rlimit sandbox. -AC_MSG_CHECKING([if select works with descriptor rlimit]) +# POSIX specifies that poll() "shall fail with EINVAL if the nfds argument +# is greater than OPEN_MAX". On some platforms that includes implementions +# ofselect in userspace on top of poll() so check both work with rlimit NOFILES +# so check that both work before enabling the rlimit sandbox. +AC_MSG_CHECKING([if select and/or poll works with descriptor rlimit]) AC_RUN_IFELSE( [AC_LANG_PROGRAM([[ #include <sys/types.h> @@ -3532,6 +3533,11 @@ AC_RUN_IFELSE( #ifdef HAVE_SYS_SELECT_H # include <sys/select.h> #endif +#ifdef HAVE_POLL_H +# include <poll.h> +#elif HAVE_SYS_POLL_H +# include <sys/poll.h> +#endif #include <errno.h> #include <fcntl.h> #include <stdlib.h> @@ -3540,6 +3546,9 @@ AC_RUN_IFELSE( int fd, r; fd_set fds; struct timeval tv; +#ifdef HAVE_POLL + struct pollfd pfd; +#endif fd = open("/dev/null", O_RDONLY); FD_ZERO(&fds); @@ -3550,7 +3559,16 @@ AC_RUN_IFELSE( tv.tv_sec = 1; tv.tv_usec = 0; r = select(fd+1, &fds, NULL, NULL, &tv); - exit (r == -1 ? 1 : 0); + if (r == -1) + exit(1); +#ifdef HAVE_POLL + pfd.fd = fd; + pfd.events = POLLIN; + r = poll(&pfd, 1, 1); + if (r == -1) + exit(2); +#endif + exit(0); ]])], [AC_MSG_RESULT([yes]) select_works_with_rlimit=yes], |