[Toybox] Stat %Z - What are valid values?

[enh]

time_t on 32-bit Android is 32 bits.

that particular value looks like a sign-extension of 0xAFBEADCE, which
is still some time in 2063. (so i'd assume this device's clock is set
wrong, and i'd assume -- since this is presumably a 32-bit device with
a signed 32-bit time_t -- that that's going to be causing other
problems too.)

https://android.googlesource.com/platform/external/toybox/+/android-6.0.1_r77/toys/other/stat.c
doesn't look to different from today.

with 64-bit toybox:

angler:/ # date 060200002064
Mon Jun  2 00:00:00 GMT 2064
angler:/ # rm /data/local/tmp/empty
angler:/ # touch /data/local/tmp/empty
angler:/ # ls -l /data/local/tmp/empty
-rw-rw-rw- 1 root root 0 2064-06-02 00:00 /data/local/tmp/empty
angler:/ # stat /data/local/tmp/empty
  File: `/data/local/tmp/empty'
  Size: 0 Blocks: 0 IO Blocks: 512 regular empty file
Device: fd00h/64768d Inode: 3014659 Links: 1
Access: (666/-rw-rw-rw-) Uid: (    0/    root) Gid: (    0/    root)
Access: 2064-06-02 00:00:11.746667836
Modify: 2064-06-02 00:00:11.746667836
Change: 2064-06-02 00:00:11.746667836
angler:/ # stat -c "%z %Z" /data/local/tmp/empty
2064-06-02 00:00:11.746667836 2979590411
angler:/ # ^D

then with 32-bit toybox:

angler:/ # ls -l /data/local/tmp/empty
-rw-rw-rw- 1 root root 0 1928-04-26 17:31 /data/local/tmp/empty
angler:/ # stat /data/local/tmp/empty
  File: `/data/local/tmp/empty'
  Size: 0 Blocks: 0 IO Blocks: 512 regular empty file
Device: fd00h/64768d Inode: 3014659 Links: 1
Access: (666/-rw-rw-rw-) Uid: (    0/    root) Gid: (    0/    root)
Access: 1928-04-26 17:31:55.746667836
Modify: 1928-04-26 17:31:55.746667836
Change: 1928-04-26 17:31:55.746667836
angler:/ # stat -c "%z %Z" /data/local/tmp/empty
1928-04-26 17:31:55.746667836 18446744072394174731

two patches attached. one avoids sign extension for all calls to
`out`, fixing %Z for systems with a signed 32-bit time_t. the other
removes void* casts unnecessary since POSIX 2008 and fixes the
strftime buffer length argument.

%z is still broken for systems with signed 32-bit time_t, but i think
that's just inherent on such systems.

On Fri, Dec 30, 2016 at 9:28 AM, darken <darken at darken.eu> wrote:
> I've seen a value of "18446744072363093454" for stat %Z (seconds since
> epoch), for some files on a users device (Android 6.01).
>
> This seems suspiciously large and I'm wondering what the valid range for
> this value is.
> What range is valid for the filesystem to return and what value range can
> toybox handle?
>
> ~Matthias
>
> _______________________________________________
> Toybox mailing list
> Toybox at lists.landley.net
> http://lists.landley.net/listinfo.cgi/toybox-landley.net
>



-- 
Elliott Hughes - http://who/enh - http://jessies.org/~enh/
Android native code/tools questions? Mail me/drop by/add me as a reviewer.
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