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| author | Eric Blake <eblake@redhat.com> | 2013-09-26 07:07:07 -0600 |
|---|---|---|
| committer | Eric Blake <eblake@redhat.com> | 2013-09-26 13:16:04 -0600 |
| commit | fdd1b511c5c12912aae79b58e0c5f6ffa0492d6e (patch) | |
| tree | 0e969daf7b52ec17b51d962720a5ec66fc9387aa /lib/dup2.c | |
| parent | 3bd0d48db800994cc10c3340c41d3242390dc68f (diff) | |
| download | gnulib-fdd1b511c5c12912aae79b58e0c5f6ffa0492d6e.tar.gz | |
dup2, dup3: work around another cygwin crasher
Cygwin 1.7.25 can crash due to an off-by-one bug on an attempt to
duplicate a file into the current RLIMIT_NOFILE soft limit, when
that limit is smaller than the hard limit. The intent in the
cygwin code was to allow the dup and auto-increase the soft limit,
which is itself questionable (and which we work around in the
gnulib getdtablesize module); but avoiding the crash is worth
doing even if the soft limit semantics are wrong.
http://cygwin.com/ml/cygwin/2013-09/msg00397.html
http://cygwin.com/ml/cygwin-developers/2013-q3/msg00010.html
* m4/dup2.m4 (gl_FUNC_DUP2): Expose the bug.
* m4/dup3.m4 (gl_FUNC_DUP3): Likewise.
* tests/test-dup2.c (main): Likewise.
* lib/dup2.c (rpl_dup2): Use setdtablesize to avoid it.
* lib/dup3.c (dup3): Likewise.
* doc/posix-functions/dup2.texi (dup2): Document it.
* doc/glibc-functions/dup3.texi (dup3): Likewise.
Signed-off-by: Eric Blake <eblake@redhat.com>
Diffstat (limited to 'lib/dup2.c')
| -rw-r--r-- | lib/dup2.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/lib/dup2.c b/lib/dup2.c index 9219eb3823..f128e7a63c 100644 --- a/lib/dup2.c +++ b/lib/dup2.c @@ -96,7 +96,11 @@ rpl_dup2 (int fd, int desired_fd) /* On Linux kernels 2.6.26-2.6.29, dup2 (fd, fd) returns -EBADF. On Cygwin 1.5.x, dup2 (1, 1) returns 0. On Cygwin 1.7.17, dup2 (1, -1) dumps core. + On Cygwin 1.7.25, dup2 (1, 256) can dump core. On Haiku, dup2 (fd, fd) mistakenly clears FD_CLOEXEC. */ +# if HAVE_SETDTABLESIZE + setdtablesize (desired_fd + 1); +# endif if (desired_fd < 0) fd = desired_fd; if (fd == desired_fd) |