[Bug libc/30477] New: riscv32: time64 does not work

[Bug libc/30477] New: riscv32: time64 does not work

[tsu.yubo at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=30477

            Bug ID: 30477
           Summary: riscv32: time64 does not work
           Product: glibc
           Version: 2.36
            Status: UNCONFIRMED
          Severity: critical
          Priority: P2
         Component: libc
          Assignee: unassigned at sourceware dot org
          Reporter: tsu.yubo at gmail dot com
                CC: drepper.fsp at gmail dot com
  Target Milestone: ---

Hi,

Please correct me if any description or my understanding is incorrect.

We found that in riscv32, time64-related system calls do not work on
glibc-2.36.
The example code is below:
```
/* From Gao Han <gaohan@iscas.ac.cn> */
#include <stdio.h>
#include <fcntl.h>
#include <sys/file.h>
#include <errno.h>
// #include <sys/flock.h>

void
setcloexec(int fd, const char *fn)
{
  int f;

  f = fcntl(fd, F_GETFD);
  if (f == -1)
    printf("unable to read filedescriptor flags for %.250s",fn);
  if (fcntl(fd, F_SETFD, (f|FD_CLOEXEC))==-1)
    printf("unable to set close-on-exec flag for %.250s",fn);
}

int main() {
    const char* dblockfile = "/var/lib/dpkg/lock";
    int dblockfd = open(dblockfile, O_RDWR|O_CREAT|O_TRUNC, 0660);
    struct flock fl;
    while(1) {

        setcloexec(dblockfd, dblockfile);

        // lock
        fl.l_type = F_WRLCK;
        fl.l_whence = SEEK_SET;
        fl.l_start = 0;
        fl.l_len = 0;
        fl.l_pid = 0;

        if (fcntl(dblockfd, F_SETLK, &fl) == -1) {
            printf("lock failed\n");
            if (errno == EINVAL) {
                printf("Invalid argument");
                break;
            }
        } else {
            printf("lock success\n");
        }

        // unlock
        fl.l_type= F_UNLCK;
        fl.l_whence= SEEK_SET;
        fl.l_start= 0;
        fl.l_len= 0;
        fl.l_pid = 0;

        if (fcntl(dblockfd, F_SETLK, &fl) == -1) {
            printf("unlock failed\n");
            if (errno == EINVAL) {
                printf("Invalid argument");
                break;
            }
        } else {
            printf("unlock success\n");
        }

        usleep(200);
    }
}
```
Yes, here we can got `Invalid argument` error. But F_SETLK64 is ok.
This problem arises when we try to build Debian riscv32 rootfs using dpkg. We
can make workaround if pass flags:
```
export DEB_CFLAGS_APPEND="${DEB_CFLAGS_APPEND:+$DEB_CFLAGS_APPEND
}-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
export DEB_CPPFLAGS_APPEND="${DEB_CPPFLAGS_APPEND:+$DEB_CPPFLAGS_APPEND
}-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"
```
In other words, we need to enable `lfs` feature. I heard the new 32-bit
platform should support time64 from start from other developers, So it's
contradictory with the fact.

We suspect that we are not ready to enable these flags but I'm not sure if
there is a historical reason for this：

```code
/* RISC-V requires 64-bit off_t */
# define _POSIX_V7_ILP32_OFF32 -1
# define _POSIX_V6_ILP32_OFF32 -1
# define _XBS5_ILP32_OFF32 -1

# define _POSIX_V7_ILP32_OFFBIG 1
# define _POSIX_V6_ILP32_OFFBIG 1
# define _XBS5_ILP32_OFFBIG     1

```

https://github.com/bminor/glibc/blob/master/sysdeps/unix/sysv/linux/riscv/bits/environments.h#L62

Please help to confirm this and I will help to fix the issue.
TIA.

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[Bug libc/30477] [RISCV]: time64 does not work on riscv32

[tsu.yubo at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=30477

Bo YU <tsu.yubo at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary|riscv32: time64 does not    |[RISCV]: time64 does not
                   |work                        |work on riscv32

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[Bug libc/30477] [RISCV]: time64 does not work on riscv32

[adhemerval.zanella at linaro dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30477

Adhemerval Zanella <adhemerval.zanella at linaro dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |adhemerval.zanella at linaro dot o
                   |                            |rg

--- Comment #1 from Adhemerval Zanella <adhemerval.zanella at linaro dot org> ---
The issue is not that time64 does not work on riscv32, but rather we overlook
the fcntl-linux.h for 32 bit with 64 bit time_t default support (it defines the
old interface values, rather than the expected 64 bit time_t ones).

This patch below should fix it, although it is essentially a ABI break:

diff --git a/sysdeps/unix/sysv/linux/bits/fcntl-linux.h
b/sysdeps/unix/sysv/linux/bits/fcntl-linux.h
index ca6a0d7516..3c15625599 100644
--- a/sysdeps/unix/sysv/linux/bits/fcntl-linux.h
+++ b/sysdeps/unix/sysv/linux/bits/fcntl-linux.h
@@ -101,7 +101,7 @@
 #endif

 #ifndef F_GETLK
-# ifndef __USE_FILE_OFFSET64
+# if !defined(__USE_FILE_OFFSET64) && __TIMESIZE != 64
 #  define F_GETLK      5       /* Get record locking info.  */
 #  define F_SETLK      6       /* Set record locking info (non-blocking).  */
 #  define F_SETLKW     7       /* Set record locking info (blocking).  */

I will send a fix upstream.

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[Bug libc/30477] [RISCV]: time64 does not work on riscv32

[adhemerval.zanella at linaro dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30477

Adhemerval Zanella <adhemerval.zanella at linaro dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at sourceware dot org   |adhemerval.zanella at linaro dot o
                   |                            |rg
         Resolution|---                         |FIXED
             Status|UNCONFIRMED                 |RESOLVED
   Target Milestone|---                         |2.38

--- Comment #2 from Adhemerval Zanella <adhemerval.zanella at linaro dot org> ---
Fixed on 2.38

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[Bug libc/30477] [RISCV]: time64 does not work on riscv32

[tsu.yubo at gmail dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=30477

--- Comment #3 from Bo YU <tsu.yubo at gmail dot com> ---
Okay, many thanks.

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[Bug libc/30477] [RISCV]: time64 does not work on riscv32

[sam at gentoo dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30477

Sam James <sam at gentoo dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |sam at gentoo dot org

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