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透過 strace 執行指令時，指令的退出狀態不同

tag-icon • tag-icon mount ftp fuse strace exit-status
透過 strace 執行指令時，指令的退出狀態不同

我可以使用以下命令正常掛載/卸載 FTP 作為檔案系統：

└──> curlftpfs -o codepage=windows-1250 anonymous:[email protected] /home/marek/ftpfs
└──> ls /home/marek/ftpfs/
1 2 3
└──> fusermount -u /home/marek/ftpfs
└──> ls /home/marek/ftpfs/
└──>

但是當我發出問題時，curlftpfs沒有strace安裝任何東西，並且進程以狀態 1 退出：

└──> strace -f curlftpfs -o codepage=windows-1250 anonymous:[email protected] /home/marek/ftpfs
└──> echo $0
1
└──> ls /home/marek/ftpfs/
└──>

最後幾行strace（完整輸出是這裡）：

[pid  9619] mprotect(0x7f08780b2000, 4096, PROT_READ) = 0
[pid  9619] mprotect(0x7f08782bd000, 4096, PROT_READ) = 0
[pid  9619] munmap(0x7f0878e8d000, 135950) = 0
[pid  9619] open("/etc/passwd", O_RDONLY|O_CLOEXEC) = 6
[pid  9619] lseek(6, 0, SEEK_CUR)       = 0
[pid  9619] fstat(6, {st_mode=S_IFREG|0644, st_size=2290, ...}) = 0
[pid  9619] mmap(NULL, 2290, PROT_READ, MAP_SHARED, 6, 0) = 0x7f0878eae000
[pid  9619] lseek(6, 2290, SEEK_SET)    = 2290
[pid  9619] munmap(0x7f0878eae000, 2290) = 0
[pid  9619] close(6)                    = 0
[pid  9619] getgid()                    = 1000
[pid  9619] getuid()                    = 1000
[pid  9619] openat(AT_FDCWD, ".", O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 6
[pid  9619] getdents(6, /* 2 entries */, 32768) = 48
[pid  9619] getdents(6, /* 0 entries */, 32768) = 0
[pid  9619] close(6)                    = 0
[pid  9619] mount("curlftpfs#ftp://anonymous:[email protected]/", ".", "fuse", MS_NOSUID|MS_NODEV, "fd=3,rootmode=40000,user_id=1000"...) = -1 EPERM (Operation not permitted)
[pid  9619] write(2, "fusermount: mount failed: Operat"..., 50fusermount: mount failed: Operation not permitted
) = 50
[pid  9619] close(3)                    = 0
[pid  9619] exit_group(1)               = ?
[pid  9618] <... recvmsg resumed> {msg_name(0)=NULL, msg_iov(1)=[{"", 1}], msg_controllen=0, msg_flags=0}, 0) = 0
[pid  9618] close(6)                    = 0
[pid  9618] wait4(9619,  <unfinished ...>
[pid  9619] +++ exited with 1 +++
<... wait4 resumed> NULL, 0, NULL)      = 9619
--- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=9619, si_uid=1000, si_status=1, si_utime=0, si_stime=0} ---
sendto(4, "QUIT\r\n", 6, MSG_NOSIGNAL, NULL, 0) = 6
poll([{fd=4, events=POLLIN|POLLPRI|POLLRDNORM|POLLRDBAND}], 1, 1000) = 1 ([{fd=4, revents=POLLIN|POLLRDNORM}])
recvfrom(4, "221 Bye\r\n", 16384, 0, NULL, NULL) = 9
close(4)                                = 0
close(3)                                = 0
exit_group(1)                           = ?
+++ exited with 1 +++

答案1

我不熟悉這個可執行文件，但我的猜測是它需要以特權運行（可能是 suid root 或類似的）。 strace -f 無法以特權運行此類進程，除非 strace 本身以 root 身份運行並且您可能需要 -u 選項。

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