Hello,
I've noticed that test-system-cmds fails on OpenBSD-CURRENT while
testing the update to guile 3.0.9:
test-system-cmds: system* exit status was 127 rather than 42
FAIL: test-system-cmds
Here's an excerpt of the ktrace of the child process while executing
that specific test: (the first fork() is the one implicitly done by
posix_spawn(3))
5590 guile RET fork 0
[...]
5590 guile CALL dup2(0,3)
5590 guile RET dup2 3
5590 guile CALL dup2(1,4)
5590 guile RET dup2 4
5590 guile CALL dup2(2,5)
5590 guile RET dup2 5
5590 guile CALL dup2(3,0)
5590 guile RET dup2 0
5590 guile CALL dup2(4,1)
5590 guile RET dup2 1
5590 guile CALL dup2(5,2)
5590 guile RET dup2 2
5590 guile CALL close(1023)
5590 guile RET close -1 errno 9 Bad file descriptor
5590 guile CALL kbind(0x7f7ffffd51f8,24,0x2b5c5ced59893fa9)
5590 guile RET kbind 0
5590 guile CALL exit(127)
(if you prefer I can provide a full ktrace of guile executing that
test case)
My interpretation is that the sequence of dup2(2) is from
posix_spawn_file_actions_adddup2 in do_spawn, while the strange
close(1023) is from close_inherited_fds_slow. Such file descriptor is
not open, so close(2) fails with EBADF and the posix_spawn machinery
exits prematurely. My current RLIMIT_NOFILE is 1024, so the number
would make sense.
On OpenBSD I've tried to use the following patch to work around the
issue:
[[[
Index: libguile/posix.c
--- libguile/posix.c.orig
+++ libguile/posix.c
@@ -1325,6 +1325,7 @@ SCM_DEFINE (scm_fork, "primitive-fork", 0, 0, 0,
static void
close_inherited_fds_slow (posix_spawn_file_actions_t *actions, int max_fd)
{
+ max_fd = getdtablecount();
while (--max_fd > 2)
posix_spawn_file_actions_addclose (actions, max_fd);
}
]]]
getdtablecount(2) returns the number of file descriptor currently open
by the process. unfortunately it doesn't seem to be portable. (well,
tbf /proc/self/fd is not portable too.)
However, while this pleases the system* test, it breaks the pipe
tests:
Running popen.test
FAIL: popen.test: open-input-pipe: echo hello
FAIL: popen.test: pipeline - arguments: (expected-value ("HELLO WORLD\n" (0
0)) actual-value ("" (127 0)))
the reason seem to be similar:
74865 guile CALL dup2(7,3)
74865 guile RET dup2 3
74865 guile CALL dup2(10,4)
74865 guile RET dup2 4
74865 guile CALL dup2(2,5)
74865 guile RET dup2 5
74865 guile CALL dup2(3,0)
74865 guile RET dup2 0
74865 guile CALL dup2(4,1)
74865 guile RET dup2 1
74865 guile CALL dup2(5,2)
74865 guile RET dup2 2
74865 guile CALL close(8)
74865 guile RET close -1 errno 9 Bad file descriptor
74865 guile CALL kbind(0x7f7ffffcfa88,24,0x2125923bdf2ca9e)
74865 guile RET kbind 0
74865 guile CALL exit(127)
I guess it's trying to close the fd of the pipe that was closed.
I'm not sure what to do from here, I'm not used to the posix_spawn_*
APIs. I'm happy to help testing diffs or by providing more info if
needed.
Thanks,
Omar Polo
