From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754853Ab3AJQ3M (ORCPT ); Thu, 10 Jan 2013 11:29:12 -0500 Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:47000 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753090Ab3AJQ3L (ORCPT ); Thu, 10 Jan 2013 11:29:11 -0500 Date: Thu, 10 Jan 2013 17:29:07 +0100 From: Florian Westphal To: Alan Cox Cc: Florian Westphal , linux-kernel@vger.kernel.org, gaowanlong@cn.fujitsu.com, gregkh@linuxfoundation.org, frank@lichtenheld.de Subject: Re: regression, bisected: openpty fails from 3.7 onwards without devpts Message-ID: <20130110162907.GB26279@breakpoint.cc> References: <20130110144626.GA26279@breakpoint.cc> <20130110155058.12f66e73@bob.linux.org.uk> MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="envbJBWh7q8WU6mo" Content-Disposition: inline In-Reply-To: <20130110155058.12f66e73@bob.linux.org.uk> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --envbJBWh7q8WU6mo Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Alan Cox wrote: > On Thu, 10 Jan 2013 15:46:26 +0100 > Florian Westphal wrote: > > Frank Lichtenheld discovered that openpty() doesn't work anymore when > > /dev/pts is not present. > > > > We bisected this down to > > > > commit bbb63c514a3464342967237a51a21ea8f61ab951 > > Author: Wanlong Gao > > Subject: drivers:tty:fix up ENOIOCTLCMD error handling [..] > > #include > > #include > > int main(void) { > > int pty_fd, tty_fd; > > if (openpty(&pty_fd, &tty_fd, NULL, NULL, NULL) != 0) { > > perror("openpty"); > > return 1; > > } > > return 0; > > } > > ---- > > [ compile with cc -lutil pty.c -o pty ] > > > > If devpts is available or above commit reverted openpty works again. > > The commit is fairly general - what we need to do here is to figure out > which specific thing trips up openpty so we can put the error on that > back as it was (or find a better way) so it still works. > > Can you attach an strace of the working/failing cases without /dev/pts Sure, attached. /dev/pts is not present. Both traces are from the same machine, with same kernel version (except above commit reverted). --envbJBWh7q8WU6mo Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="openpty.ok.trace.txt" execve("./ptytest", ["./ptytest"], [/* 7 vars */]) = 0 brk(0) = 0x1d04000 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe6784d0000 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory) open("/etc/ld.so.cache", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=15432, ...}) = 0 mmap(NULL, 15432, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7fe6784cc000 close(3) = 0 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/libutil.so.1", O_RDONLY) = 3 read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\20\16\0\0\0\0\0\0"..., 832) = 832 fstat(3, {st_mode=S_IFREG|0644, st_size=10640, ...}) = 0 mmap(NULL, 2105608, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fe6780b0000 mprotect(0x7fe6780b2000, 2093056, PROT_NONE) = 0 mmap(0x7fe6782b1000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1000) = 0x7fe6782b1000 close(3) = 0 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY) = 3 read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\300\357\1\0\0\0\0\0"..., 832) = 832 fstat(3, {st_mode=S_IFREG|0755, st_size=1595408, ...}) = 0 mmap(NULL, 3709016, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7fe677d26000 mprotect(0x7fe677ea6000, 2097152, PROT_NONE) = 0 mmap(0x7fe6780a6000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x180000) = 0x7fe6780a6000 mmap(0x7fe6780ab000, 18520, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fe6780ab000 close(3) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe6784cb000 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe6784ca000 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe6784c9000 arch_prctl(ARCH_SET_FS, 0x7fe6784ca700) = 0 mprotect(0x7fe6780a6000, 16384, PROT_READ) = 0 mprotect(0x7fe6782b1000, 4096, PROT_READ) = 0 mprotect(0x7fe6784d2000, 4096, PROT_READ) = 0 munmap(0x7fe6784cc000, 15432) = 0 open("/dev/ptmx", O_RDWR) = -1 ENOSPC (No space left on device) open("/dev/ptyp0", O_RDWR) = 3 ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B38400 opost isig icanon echo ...}) = 0 ioctl(3, TIOCGPTN, [0]) = -1 EINVAL (Invalid argument) fstat(3, {st_mode=S_IFCHR|S_ISVTX|0666, st_rdev=makedev(2, 0), ...}) = 0 stat("/dev/ttyp0", {st_mode=S_IFCHR|S_ISVTX|0660, st_rdev=makedev(3, 0), ...}) = 0 getuid() = 0 socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 4 connect(4, {sa_family=AF_FILE, path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory) close(4) = 0 socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 4 connect(4, {sa_family=AF_FILE, path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory) close(4) = 0 brk(0) = 0x1d04000 brk(0x1d25000) = 0x1d25000 open("/etc/nsswitch.conf", O_RDONLY) = 4 fstat(4, {st_mode=S_IFREG|0644, st_size=475, ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe6784cf000 read(4, "# /etc/nsswitch.conf\n#\n# Example"..., 4096) = 475 read(4, "", 4096) = 0 close(4) = 0 munmap(0x7fe6784cf000, 4096) = 0 open("/etc/ld.so.cache", O_RDONLY) = 4 fstat(4, {st_mode=S_IFREG|0644, st_size=15432, ...}) = 0 mmap(NULL, 15432, PROT_READ, MAP_PRIVATE, 4, 0) = 0x7fe6784cc000 close(4) = 0 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/libnss_compat.so.2", O_RDONLY) = 4 read(4, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0`\22\0\0\0\0\0\0"..., 832) = 832 fstat(4, {st_mode=S_IFREG|0644, st_size=31584, ...}) = 0 mmap(NULL, 2127048, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 4, 0) = 0x7fe677b1e000 mprotect(0x7fe677b25000, 2093056, PROT_NONE) = 0 mmap(0x7fe677d24000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 4, 0x6000) = 0x7fe677d24000 close(4) = 0 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/libnsl.so.1", O_RDONLY) = 4 read(4, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0 @\0\0\0\0\0\0"..., 832) = 832 fstat(4, {st_mode=S_IFREG|0644, st_size=89056, ...}) = 0 mmap(NULL, 2194128, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 4, 0) = 0x7fe677906000 mprotect(0x7fe67791b000, 2093056, PROT_NONE) = 0 mmap(0x7fe677b1a000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 4, 0x14000) = 0x7fe677b1a000 mmap(0x7fe677b1c000, 6864, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7fe677b1c000 close(4) = 0 mprotect(0x7fe677b1a000, 4096, PROT_READ) = 0 mprotect(0x7fe677d24000, 4096, PROT_READ) = 0 munmap(0x7fe6784cc000, 15432) = 0 open("/etc/ld.so.cache", O_RDONLY) = 4 fstat(4, {st_mode=S_IFREG|0644, st_size=15432, ...}) = 0 mmap(NULL, 15432, PROT_READ, MAP_PRIVATE, 4, 0) = 0x7fe6784cc000 close(4) = 0 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/libnss_nis.so.2", O_RDONLY) = 4 read(4, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0 \0\0\0\0\0\0"..., 832) = 832 fstat(4, {st_mode=S_IFREG|0644, st_size=43552, ...}) = 0 mmap(NULL, 2139320, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 4, 0) = 0x7fe6776fb000 mprotect(0x7fe677705000, 2093056, PROT_NONE) = 0 mmap(0x7fe677904000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 4, 0x9000) = 0x7fe677904000 close(4) = 0 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/libnss_files.so.2", O_RDONLY) = 4 read(4, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\200!\0\0\0\0\0\0"..., 832) = 832 fstat(4, {st_mode=S_IFREG|0644, st_size=47616, ...}) = 0 mmap(NULL, 2143624, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 4, 0) = 0x7fe6774ef000 mprotect(0x7fe6774fa000, 2093056, PROT_NONE) = 0 mmap(0x7fe6776f9000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 4, 0xa000) = 0x7fe6776f9000 close(4) = 0 mprotect(0x7fe6776f9000, 4096, PROT_READ) = 0 mprotect(0x7fe677904000, 4096, PROT_READ) = 0 munmap(0x7fe6784cc000, 15432) = 0 open("/etc/group", O_RDONLY|O_CLOEXEC) = 4 lseek(4, 0, SEEK_CUR) = 0 fstat(4, {st_mode=S_IFREG|0644, st_size=578, ...}) = 0 mmap(NULL, 578, PROT_READ, MAP_SHARED, 4, 0) = 0x7fe6784cf000 lseek(4, 578, SEEK_SET) = 578 munmap(0x7fe6784cf000, 578) = 0 close(4) = 0 chown("/dev/ttyp0", 0, 5) = 0 chmod("/dev/ttyp0", 0620) = 0 ioctl(3, TIOCSPTLCK, [0]) = 0 ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B38400 opost isig icanon echo ...}) = 0 ioctl(3, TIOCGPTN, [0]) = -1 EINVAL (Invalid argument) fstat(3, {st_mode=S_IFCHR|S_ISVTX|0666, st_rdev=makedev(2, 0), ...}) = 0 stat("/dev/ttyp0", {st_mode=S_IFCHR|0620, st_rdev=makedev(3, 0), ...}) = 0 open("/dev/ttyp0", O_RDWR|O_NOCTTY) = 4 fstat(1, {st_mode=S_IFCHR|0600, st_rdev=makedev(5, 1), ...}) = 0 ioctl(1, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 opost isig icanon echo ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7fe6784cf000 write(1, "got 3 4\n", 8) = 8 rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0 rt_sigaction(SIGCHLD, NULL, {SIG_DFL, [], 0}, 8) = 0 rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0 nanosleep({100, 0}, 0x7fffa8389270) = 0 exit_group(0) = ? --envbJBWh7q8WU6mo Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="openpty.fail.trace.txt" execve("./ptytest", ["./ptytest"], [/* 7 vars */]) = 0 brk(0) = 0x1df4000 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f207c0e4000 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory) open("/etc/ld.so.cache", O_RDONLY) = 3 fstat(3, {st_mode=S_IFREG|0644, st_size=15432, ...}) = 0 mmap(NULL, 15432, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f207c0e0000 close(3) = 0 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/libutil.so.1", O_RDONLY) = 3 read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\20\16\0\0\0\0\0\0"..., 832) = 832 fstat(3, {st_mode=S_IFREG|0644, st_size=10640, ...}) = 0 mmap(NULL, 2105608, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f207bcc4000 mprotect(0x7f207bcc6000, 2093056, PROT_NONE) = 0 mmap(0x7f207bec5000, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1000) = 0x7f207bec5000 close(3) = 0 access("/etc/ld.so.nohwcap", F_OK) = -1 ENOENT (No such file or directory) open("/lib/x86_64-linux-gnu/libc.so.6", O_RDONLY) = 3 read(3, "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\300\357\1\0\0\0\0\0"..., 832) = 832 fstat(3, {st_mode=S_IFREG|0755, st_size=1595408, ...}) = 0 mmap(NULL, 3709016, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f207b93a000 mprotect(0x7f207baba000, 2097152, PROT_NONE) = 0 mmap(0x7f207bcba000, 20480, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x180000) = 0x7f207bcba000 mmap(0x7f207bcbf000, 18520, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f207bcbf000 close(3) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f207c0df000 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f207c0de000 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f207c0dd000 arch_prctl(ARCH_SET_FS, 0x7f207c0de700) = 0 mprotect(0x7f207bcba000, 16384, PROT_READ) = 0 mprotect(0x7f207bec5000, 4096, PROT_READ) = 0 mprotect(0x7f207c0e6000, 4096, PROT_READ) = 0 munmap(0x7f207c0e0000, 15432) = 0 open("/dev/ptmx", O_RDWR) = -1 ENOSPC (No space left on device) open("/dev/ptyp0", O_RDWR) = 3 ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B38400 opost isig icanon echo ...}) = 0 ioctl(3, TIOCGPTN, [0]) = -1 ENOTTY (Inappropriate ioctl for device) stat("", 0x7fff02b175d0) = -1 ENOENT (No such file or directory) fcntl(3, F_GETFD) = 0 close(3) = 0 dup(2) = 3 fcntl(3, F_GETFL) = 0x8002 (flags O_RDWR|O_LARGEFILE) brk(0) = 0x1df4000 brk(0x1e15000) = 0x1e15000 fstat(3, {st_mode=S_IFCHR|0600, st_rdev=makedev(5, 1), ...}) = 0 ioctl(3, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 opost isig icanon echo ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f207c0e3000 lseek(3, 0, SEEK_CUR) = -1 ESPIPE (Illegal seek) write(3, "openpty: No such file or directo"..., 35) = 35 close(3) = 0 munmap(0x7f207c0e3000, 4096) = 0 fstat(1, {st_mode=S_IFCHR|0600, st_rdev=makedev(5, 1), ...}) = 0 ioctl(1, SNDCTL_TMR_TIMEBASE or TCGETS, {B9600 opost isig icanon echo ...}) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f207c0e3000 write(1, "got -1 -1\n", 10) = 10 exit_group(1) = ? --envbJBWh7q8WU6mo--