On unix if exec.Command() is given both ExtraFiles and Ctty, and the
Ctty file descriptor overlaps the range of FDs intended for the child,
then cmd.Start() the ioctl(fd,TIOCSCTTY) call fails with an
"inappropriate ioctl for device" error.
When child file descriptors overlap the new child's ctty the ctty will
be closed in the fd shuffle before the TIOCSCTTY. Thus TIOCSCTTY is
used on one of the ExtraFiles rather than the intended Ctty file. Thus
the error.
exec.Command() callers can workaround this by ensuring the Ctty fd is
larger than any ExtraFiles destined for the child.
Fix this by doing the ctty ioctl before the fd shuffle.
Test for this issue by modifying TestTerminalSignal to use more
ExtraFiles. The test fails on linux and freebsd without this change's
syscall/*.go changes. Other platforms (e.g. darwin, aix, solaris) have
the same fd shuffle logic, so the same fix is applied to them. However,
I was only able to test on linux (32 and 64 bit) and freebsd (64 bit).
Manual runs of the test in https://golang.org/issue/29458 start passing
with this patch:
Before:
% /tmp/src/go/bin/go run t
successfully ran child process with ParentExtraFileFdNum=5, ChildExtraFileFd=6, ParentPtyFd=7
panic: failed to run child process with ParentExtraFileFdNum=10, ChildExtraFileFd=11, ParentPtyFd=11: fork/exec /bin/true: inappropriate ioctl for device
After:
% /tmp/src/go/bin/go run t
successfully ran child process with ParentExtraFileFdNum=5, ChildExtraFileFd=6, ParentPtyFd=7
successfully ran child process with ParentExtraFileFdNum=10, ChildExtraFileFd=11, ParentPtyFd=11
Fixes#29458
Change-Id: I99513de7b6073c7eb855f1eeb4d1f9dc0454ef8b
Reviewed-on: https://go-review.googlesource.com/c/go/+/178919
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
On AIX, sys.Pgid must be a int32 and not a int64 as on Solaris for ioctl
syscall.
Pid_t type can be used to provide the same code in both OS. But pid_t
must be added to ztypes_solaris_amd64.go.
Change-Id: I1dbe57f099f9e5ac9491aaf246a521137eea5014
Reviewed-on: https://go-review.googlesource.com/c/144539
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
AIX and Solaris both requires libc to make any syscalls and their
implementation is really similar.
Therefore, Solaris files reused by AIX have their name changed to *_libc.
exec_libc.go is also adapted to AIX.
Updates: #25893
Change-Id: I50d1d7b964831637013d5e64799187cd9565c42b
Reviewed-on: https://go-review.googlesource.com/c/138719
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Damien Neil
Greg Thelen
Clément Chigot