From: Ken Brown <kbrown@cornell.edu>
To: Jeremy Drake <cygwin@jdrake.com>
Cc: Takashi Yano <takashi.yano@nifty.ne.jp>, cygwin-patches@cygwin.com
Subject: Re: [PATCH] fhandler_pipe: add sanity limit to handle loops
Date: Sun, 26 Dec 2021 10:09:57 -0500 [thread overview]
Message-ID: <c7664703-0ec2-388f-64e3-8c46d4590b3e@cornell.edu> (raw)
In-Reply-To: <alpine.BSO.2.21.2112252054310.11760@resin.csoft.net>
On 12/25/2021 11:56 PM, Jeremy Drake wrote:
> I set up a windows server 2022 VM last night and went nuts stressing
> pacman/GPGME. I was able to reproduce the issue there:
>
> status = 0x00000000, phi->NumberOfHandles = 8261392, n_handle = 256
> [#####----------------------------------] 14%
> assertion "phi->NumberOfHandles <= n_handle" failed: file
> "../../.././winsup/cygwin/fhandler_pipe.cc", line 1281, function: void*
> fhandler_pipe::get_query_hdl_per_process(WCHAR*, OBJECT_NAME_INFORMATION*)
>
> So it is not something inherent in the x86_64-on-ARM64 emulation but can
> happen on native x86_64 also.
A Google search led me to something that might explain what's going on. Look at
the function PhEnumHandlesEx2 starting at line 5713 in
https://github.com/processhacker/processhacker/blob/master/phlib/native.c#L5152
Two interesting things:
1. For some processes, NtQueryInformationProcess(ProcessHandleInformation) can
return STATUS_SUCCESS with invalid handle information. See the comment starting
at line 5754, where it is shown how to detect this.
2. You can use the ReturnLength parameter of NtQueryInformationProcess to see
how big a buffer is needed. This might be more efficient than repeatedly
doubling the buffer size.
Ken
next prev parent reply other threads:[~2021-12-26 15:10 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-23 23:10 Jeremy Drake
2021-12-24 0:06 ` Ken Brown
2021-12-24 0:29 ` Jeremy Drake
2021-12-24 17:17 ` Ken Brown
2021-12-24 19:42 ` Jeremy Drake
2021-12-24 22:46 ` Ken Brown
2021-12-24 23:42 ` Jeremy Drake
2021-12-25 0:39 ` Jeremy Drake
2021-12-25 3:19 ` Takashi Yano
2021-12-25 3:47 ` Jeremy Drake
2021-12-25 4:12 ` Takashi Yano
2021-12-25 5:40 ` Jeremy Drake
2021-12-25 17:10 ` Takashi Yano
2021-12-25 17:16 ` Takashi Yano
2021-12-25 19:00 ` Marco Atzeri
2021-12-25 19:20 ` Jeremy Drake
2021-12-25 22:18 ` Ken Brown
2021-12-25 23:00 ` Jeremy Drake
2021-12-26 3:04 ` Ken Brown
2021-12-26 4:56 ` Jeremy Drake
2021-12-26 15:09 ` Ken Brown [this message]
2021-12-26 16:04 ` Ken Brown
2021-12-26 16:24 ` Ken Brown
2021-12-26 21:35 ` Jeremy Drake
2021-12-26 22:18 ` Ken Brown
2021-12-26 22:43 ` Jeremy Drake
2021-12-26 23:12 ` Ken Brown
2021-12-26 23:23 ` Jeremy Drake
2021-12-27 2:42 ` Ken Brown
2021-12-27 21:12 ` Jeremy Drake
2021-12-29 21:59 ` Ken Brown
2021-12-29 23:29 ` Jeremy Drake
2021-12-27 20:01 ` Jon Turney
2021-12-29 5:45 ` Jeremy Drake
2021-12-30 15:44 ` Jon Turney
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