From: Corinna Vinschen <corinna-cygwin@cygwin.com>
To: cygwin@cygwin.com
Subject: Re: Privilege(s) needed to run top command
Date: Mon, 11 Mar 2019 21:28:00 -0000 [thread overview]
Message-ID: <20190311212845.GE3785@calimero.vinschen.de> (raw)
In-Reply-To: <87r2bd4003.fsf@Rainer.invalid>
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On Mar 11 21:41, Achim Gratz wrote:
> jwang writes:
> > This is used to work for a ordinary login.
> >
> > After re-install, top does not show the true load et al. Nor processes
> > owned by SYSTEM.
> >
> > Please shed some light.
>
> Cygwin is a user-space layer. It can't show you information that the
> underlying OS determines to be off-limits for you.
And I just checked, even under Cygwin 2.11.2, procps and top were
not showing foreign processes if you're running under a non-admin
user account or a non-elevated shell, so this is nothing new.
In fact, `procps' at least tries to access /proc/<PID>/stat. This
doesn't return valid information because it has to be able to open a
process with PROCESS_QUERY_LIMITED_INFORMATION and PROCESS_VM_READ
permissions. No ordinary user has these permissions on processes she
doesn't own.(*)
However, Cygwin's `ps -e' was supposed to show all processes, but
it didn't anymore since I created helper objects in the NT namespace
with insufficient privileges for everyone. I pushed a patch and
uploaded new developer snapshots to https://cywin.com/snapshots/
for testing.
Thanks,
Corinna
(*) That doesn't mean it's not possible. In theory all Cygwin
processes could be opened to allow everyone
PROCESS_QUERY_LIMITED_INFORMATION access, which would at least
fill most of /proc/<PID>/stat for foreign processes.
However, we never did that, so it can't have worked yet.
--
Corinna Vinschen
Cygwin Maintainer
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next prev parent reply other threads:[~2019-03-11 21:28 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-11 16:56 jwang
2019-03-11 20:29 ` L A Walsh
2019-03-11 20:41 ` Achim Gratz
2019-03-11 21:28 ` Corinna Vinschen [this message]
2019-03-11 21:40 ` Achim Gratz
2019-03-12 0:20 ` Andrey Repin
2019-03-12 8:58 ` Corinna Vinschen
2019-03-12 9:48 ` jwang
2019-03-12 11:14 ` Corinna Vinschen
2019-03-12 12:01 ` jwang
2019-03-12 12:39 ` Houder
2019-03-12 15:51 ` jwang
2019-03-12 16:47 ` Corinna Vinschen
2019-03-12 17:06 ` jwang
2019-03-12 17:13 ` Corinna Vinschen
2019-03-12 17:19 ` jwang
2019-03-12 17:40 ` Corinna Vinschen
2019-03-12 17:39 ` Corinna Vinschen
2019-03-12 20:28 ` Corinna Vinschen
2019-03-12 20:50 ` Andrey Repin
2019-03-12 20:59 ` Corinna Vinschen
2019-03-12 21:50 ` Andrey Repin
2019-03-12 18:10 ` Houder
2019-03-12 19:27 ` Achim Gratz
2019-03-13 9:17 ` jwang
2019-03-15 10:20 ` jwang
2019-03-15 11:28 ` Corinna Vinschen
2019-03-15 12:34 ` jwang
2019-03-15 13:38 ` Corinna Vinschen
2019-03-15 13:50 ` jwang
2019-03-15 14:11 ` jwang
2019-03-15 14:53 ` Corinna Vinschen
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