Hello
On 31/05/2022 10:33, Arnd Bergmann wrote:
(cc correct libc-alpha list, sorry for the typo)
On Tue, May 31, 2022 at 10:24 AM Arnd Bergmann<a...@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'm using Buildroot, I added it to TARGET_CPPFLAGS (also used by
TARGET_CLAGS) and HOST_CPPFLAGS (used by HOST_CFLAGS) in
buildroot/package/Makefile.in
Then all packages are built with the option (unless the package filter
it out, I had to create patches for few of them).
Extracts of logs while rebuild openssh:
/home/arnaud/devenv/branches/kernel510/output/host/bin/i686-buildroot-linux-gnu-gcc
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -Os -g0
-D_FORTIFY_SOURCE=1 -pipe -Wno-error=format-truncation -Wall -Wextra
-Wpointer-arith
-Wuninitialized -Wsign-compare -Wformat-security
-Wsizeof-pointer-memaccess -Wno-pointer-sign -Wno-unused-parameter
-Wno-unused-result -Wimplicit-fallthrough -fno-strict-aliasing -ftrapv
-fno-builtin-memset -fstack-protector-strong -fPIC -I. -I.. -I. -I./..
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64
-D_XOPEN_SOURCE=600 -D_BSD_SOURCE -D_DEFAULT_SOURCE -DHAVE_CONFIG_H -c
daemon.c
/home/arnaud/devenv/branches/kernel510/output/host/bin/i686-buildroot-linux-gnu-gcc
-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -Os -g0
-D_FORTIFY_SOURCE=1 -pipe -Wno-error=format-truncation -Wall -Wextra
-Wpointer-arith
-Wuninitialized -Wsign-compare -Wformat-security
-Wsizeof-pointer-memaccess -Wno-pointer-sign -Wno-unused-parameter
-Wno-unused-result -Wimplicit-fallthrough -fno-strict-aliasing -ftrapv
-fno-builtin-memset -fstack-protector-strong -fPIE -I. -I.
-D_LARGEFILE_SOURCE
-D_FILE_OFFSET_BITS=64 -D_TIME_BITS=64 -D_XOPEN_SOURCE=600
-D_BSD_SOURCE -D_DEFAULT_SOURCE -DSSHDIR=\"/etc/ssh\"
-D_PATH_SSH_PROGRAM=\"/usr/bin/ssh\"
-D_PATH_SSH_ASKPASS_DEFAULT=\"/usr/libexec/ssh-askpass\"
-D_PATH_SFTP_SERVER=\"/usr/libexec/sftp-server\"
-D_PATH_SSH_KEY_SIGN=\"/usr/libexec/ssh-keysign\"
-D_PATH_SSH_PKCS11_HELPER=\"/usr/libexec/ssh-pkcs11-helper\"
-D_PATH_SSH_SK_HELPER=\"/usr/libexec/ssh-sk-helper\"
-D_PATH_SSH_PIDDIR=\"/var/run\"
-D_PATH_PRIVSEP_CHROOT_DIR=\"/var/empty\" -DHAVE_CONFIG_H -c
sshd.c -o sshd.o
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);
}
__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?
I'd tried previously to build the entire distro with musl without
success, not sure I can do it only for openssh.
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.panaio...@gmx.fr <mailto:Arnaud Panaïotis
<arnaud.panaio...@gmx.fr>>
18 place Jean Moulin - 38000 Grenoble
APsudo - www.panaiotis.fr <https://www.panaiotis.fr>
--
L'absence de virus dans ce courrier électronique a été vérifiée par le logiciel
antivirus Avast.
https://www.avast.com/antivirus
_______________________________________________
Y2038 mailing list -- y2038@lists.linaro.org
To unsubscribe send an email to y2038-le...@lists.linaro.org
