Messages in this thread | | | Date | Tue, 31 May 2022 14:16:58 +0200 | Subject | Re: PROBLEM: with daemon.c after y2038 on 32-bits Kernel | From | Arnaud Panaïotis <> |
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Hello,
On 31/05/2022 12:54, Adhemerval Zanella wrote: > > On 31/05/2022 05:33, Arnd Bergmann via Libc-alpha wrote: >> (cc correct libc-alpha list, sorry for the typo) >> >> On Tue, May 31, 2022 at 10:24 AM Arnd Bergmann <arnd@kernel.org> wrote: >>> On 17/05/2022 09:51, Arnaud Panaïotis wrote: >>>> I'm working for a client to generate embedded 32-bits Linux Kernel working after y2038 issue. >>>> >>>> I generated a 5.15 Kernel thought Buildroot with Coreutils 9.0, GCC 11.2.0, Binutils 2.37, Glibc 2.34-9 and CFLAGS -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64. >>>> >>>> I encounter an issue while working with OpenSSH (I initially contacted them before). >>> To clarify: did you build just openssh with -D_TIME_BITS=64, or did >>> you build the entire user space this way?
I made a patch for the whole Builroot, this way all packages are built with it (unless it is filter-out, I had to make few patches).
Option is present in build log for daemon.c and sshd.c
>>> >>>> After 2038, /usr/sbin/sshd does not create an error but it child does generate this one: >>>> daemon() failed: Value too large for defined data type >>>> >>>> This happend here in sshd.c: >>>> >>>> 2019 /* >>>> 2020 * If not in debugging mode, not started from inetd and not already >>>> 2021 * daemonized (eg re-exec via SIGHUP), disconnect from the controlling >>>> 2022 * terminal, and fork. The original process exits. >>>> 2023 */ >>>> 2024 already_daemon = daemonized(); >>>> 2025 if (!(debug_flag || inetd_flag || no_daemon_flag || already_daemon)) { >>>> 2026 >>>> 2027 if (daemon(0, 0) == -1) >>>> 2028 fatal("daemon() failed: %.200s", strerror(errno)); >>> My guess is that there are parts of glibc that are not fully >>> y2038-safe at the moment, but >>> merely provide the interfaces for time64 applications. >>> >>> >>> In the glibc code, I see >>> >>> int >>> daemon (int nochdir, int noclose) >>> { >>> ... >>> if ((fd = __open_nocancel(_PATH_DEVNULL, O_RDWR, 0)) != -1 >>> && (__builtin_expect (__fstat64 (fd, &st), 0) >>> == 0)) { >>> ... >>> } else { >>> __close_nocancel_nostatus (fd); >>> return -1; >>> } >>> return (0); >>> } > Thanks for catching it, I have opened a bug report for it [1] and I will fix > and backport to 2.34 and 2.35. > > [1] https://sourceware.org/bugzilla/show_bug.cgi?id=29203 Thanks, I'll watch this. > >>> __fstatat64 (int fd, const char *file, struct stat64 *buf, int flags) >>> { >>> struct __stat64_t64 st_t64; >>> return __fstatat64_time64 (fd, file, &st_t64, flags) >>> ?: __cp_stat64_t64_stat64 (&st_t64, buf); >>> } >>> >>> If I'm reading this correctly, daemon() internally uses the time32 >>> version of 'stat', which fails for files with out-of-range timestamps. >>> Are you able to rebuild the ssh binary (or your entire distro, if that's >>> easier) against musl-1.2.x instead of glibc to see if the same thing >>> happens there?
Musl did not worked previously for me, not sure for openssh only within Buildroot.
I'll test the patch from ticket 29203, probably the easiest solution for me.
>>> >>> Arnd >>> >>>> To reproduce: >>>> >>>> # date -s "2040-05-12" >>>> # hwclock --systohc >>>> # reboot >>>> # /usr/sbin/sshd >>>> >>>> Note this error occurs only after the reboot, and setting a date before 2038 also require a reboot to remove the error. >>>> >>>> strace and gdb trace linked. >>>> >>>> Let me know if you need additional information. --
*Arnaud PANAÏOTIS* | Lead Developer Freelance +33 6 34 82 12 62 | arnaud.panaiotis@gmx.fr <mailto:Arnaud Panaïotis <arnaud.panaiotis@gmx.fr>>
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-- L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel antivirus Avast. https://www.avast.com/antivirus
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