On Wed, Oct 24, 2012 at 10:01 AM, Uros Bizjak <ubiz...@gmail.com> wrote:
>>> Additional test fails on alphaev68-linux-gnu:
>>>
>>> --- FAIL: TestPassFD (0.15 seconds)
>>> passfd_test.go:62: FileConn: dup: Bad file descriptor
>>> FAIL
>>> FAIL: syscall
>>
>> As far as I can see this error message occurs when calling dup on the
>> second file descriptor returned by socketpair. But I can't see why
>> that would fail on Alpha.
>
> For some reason, the second dup on the same file descriptor fails.
> Attached, please find strace dump, where:
>
> ...
> gettimeofday({1351064744, 381316}, NULL) = 0
> gettimeofday({1351064744, 381316}, NULL) = 0
> gettimeofday({1351064744, 382293}, NULL) = 0
> gettimeofday({1351064744, 382293}, NULL) = 0
> gettimeofday({1351064744, 382293}, NULL) = 0
> dup(4) = 9
> osf_sigprocmask(SIG_BLOCK, []) = 0 (old mask [])
> mmap(NULL, 24704, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
> 0) = 0x20003076000
> mprotect(0x20003076000, 8192, PROT_NONE) = 0
> clone(child_stack=0x2000307ab70,
> flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID,
> parent_tidptr=0x2000307b350, tls=0x2000307b970,
> child_tidptr=0x2000307b350) = 21544
> fcntl(9, F_SETFD, FD_CLOEXEC) = 0
> osf_sigprocmask(SIG_BLOCK, []) = 0 (old mask [])
> sigreturn() (mask [SYS STOP TSTP IO USR2]) = 0
> mmap(NULL, 24704, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1,
> 0) = 0x2000307e000
> mprotect(0x2000307e000, 8192, PROT_NONE) = 0
> clone(child_stack=0x20003082b70,
> flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS|CLONE_PARENT_SETTID|CLONE_CHILD_CLEARTID,
> parent_tidptr=0x20003083350, tls=0x20003083970,
> child_tidptr=0x20003083350) = 21545
> futex(0x20000c4a450, FUTEX_WAIT, 0, NULL) = 0
> sigreturn() (mask [ILL ABRT FPE KILL BUS ALRM URG CONT IO XCPU]) = 0
> osf_sigprocmask(SIG_BLOCK, []) = 0 (old mask [])
> futex(0xf84042b248, FUTEX_WAKE, 1) = 1
> wait4(21546, [{WIFEXITED(s) && WEXITSTATUS(s) == 0}], 0, {ru_utime={0,
> 51757}, ru_stime={0, 21484}, ...}) = 21546
> osf_sigprocmask(SIG_BLOCK, []) = 0 (old mask [])
> close(9) = 0
> dup(4) = -1 EBADF (Bad file descriptor)
> open("./a.out", O_RDONLY|O_CLOEXEC) = 3
> ...
>
> Is it OK to call dup on the same FD the second time?
To answer my own question:
dup(4) = 9
...
close(9) = 0
dup(4) = -1 EBADF (Bad file descriptor)
Test is calling dup on a closed file descriptor. FD 4 and 9 share file
status flags.
Uros.
