From: Po Lu <luangruo@yahoo.com>
To: Bruno Haible <bruno@clisp.org>
Cc: "Paul Eggert" <eggert@cs.ucla.edu>,
"Robert Pluim" <rpluim@gmail.com>,
bug-gnulib@gnu.org, "Pádraig Brady" <P@draigbrady.com>,
"Sven Joachim" <svenjoac@gmx.de>,
64937@debbugs.gnu.org, "Natanael Copa" <natanael.copa@gmail.com>,
Emacs-devel@gnu.org, "Thorsten Kukuk" <kukuk@suse.com>
Subject: Re: boot time on Linux
Date: Thu, 10 Aug 2023 10:14:27 +0800 [thread overview]
Message-ID: <875y5nve2k.fsf@yahoo.com> (raw)
In-Reply-To: <5962135.d8TiXCRyrx@nimes> (Bruno Haible's message of "Thu, 10 Aug 2023 02:14:20 +0200")
Bruno Haible <bruno@clisp.org> writes:
> Po Lu wrote:
>> > Also, I don't know how Android records boot time so I'll cc this to Po
>> > Lu, the main developer for Emacs on Android.
>>
>> The boot time is off limits to user programs on Android, for security
>> reasons.
>
> No, it isn't. The attached file, when compiled and run under Termux (which
> doesn't have particular permissions), prints e.g.:
>
> from clock : 1691616762.476870660 = 2023-08-09 21:32:42.476870660
> from sysinfo: 1691616762.329261637 = 2023-08-09 21:32:42.329261637
>
> Note that this uses the kernel's uptime counter, so it will not work well
> when the user changes the current time manually. But this is rare on Android.
This uses the uptime counter (which also results in an SELinux denial
for me, but different Android distributions have SELinux policies of
varying strictness), which cannot establish the precise time the system
started, since time elapses between the read from the uptime counter and
the read from the RTC.
next prev parent reply other threads:[~2023-08-10 2:14 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <87tttmpt5h.fsf@turtle.gmx.de>
[not found] ` <20230808173430.GA27131@suse.com>
[not found] ` <26226778.6c9BZvbsD2@nimes>
[not found] ` <3732835.vtg8X0x55z@nimes>
2023-08-09 19:31 ` boot time on Linux Paul Eggert
2023-08-09 21:06 ` Bruno Haible
2023-08-09 23:53 ` Po Lu
2023-08-10 0:14 ` Bruno Haible
2023-08-10 2:14 ` Po Lu [this message]
2023-08-10 6:22 ` Paul Eggert
2023-08-10 6:58 ` Po Lu
2023-08-10 10:30 ` Bruno Haible
2023-08-10 12:23 ` bug#64937: " Po Lu via GNU coreutils Bug Reports
2023-08-10 12:25 ` Bruno Haible
2023-08-10 13:04 ` Po Lu
2023-08-10 14:12 ` Bruno Haible
2023-08-11 8:27 ` Po Lu
2023-08-10 9:30 ` Natanael Copa
2023-08-10 9:38 ` Po Lu
2023-08-10 10:05 ` Natanael Copa
2023-08-10 15:30 ` Bruno Haible
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