From: Florian Weimer <fweimer@redhat.com>
To: Baojun Wang <wangbj@gmail.com>
Cc: libc-help@sourceware.org
Subject: Re: dlmopen in LD_PRELOAD
Date: Fri, 21 Jun 2019 11:53:00 -0000 [thread overview]
Message-ID: <87a7ebxihi.fsf@oldenburg2.str.redhat.com> (raw)
In-Reply-To: <CAC+a-TYjvBbS78ETG9qS_1VjkS6j2A2FAM5KJM_gmHKVcRPz9Q@mail.gmail.com> (Baojun Wang's message of "Tue, 18 Jun 2019 00:14:53 -0400")
* Baojun Wang:
> Hi Florian,
>
> (re-send because previous email failed to send due to attachment)
>
> I made a tiny project this issue, it didn't show the same failure, however it did segfaults inside the library being `dlmopen`-ed.
>
> link: `git clone https://github.com/wangbj/dlns-test.git`
> (sorry attachment seems to cause failure to send message)
>
> run.c: an launcher to inject DSOs.
> preload.c: a mini loader using LD_PRELOAD -> dlmopen
> dlns.c: DSO being `dlmopen`-ed
> app.c: app being injected with DSOs.
>
> running `make test` should reproduce the issue. (need to run `ulimit
> -c unlimited` to get core dump).
Sorry, for me, it does not.
This is the output I get:
./run libpreload.so libdlns.so ./app
open /tmp/dlns-test/libdlns.so
dlns_init
[link_map] dso: /tmp/dlns-test/libdlns.so, loaded at: 0x7f0ca0d53000, _DYNAMIC: 0x7f0ca0d56de8
[link_map] dso: /lib64/libdl.so.2, loaded at: 0x7f0ca0d4d000, _DYNAMIC: 0x7f0ca0d51d70
[link_map] dso: /lib64/libpthread.so.0, loaded at: 0x7f0ca0b12000, _DYNAMIC: 0x7f0ca0b2dd60
[link_map] dso: /lib64/libc.so.6, loaded at: 0x7f0ca094c000, _DYNAMIC: 0x7f0ca0b0bb60
[link_map] dso: /lib64/ld-linux-x86-64.so.2, loaded at: (nil), _DYNAMIC: (nil)
#1 local_getpid addr = 0x401610
#0 local_getpid addr = 0x401610
#2 local_getpid addr = 0x401610
#3 local_getpid addr = 0x401610
#1 local_getpid: 0
#1 local_getpid: 0
#1 my own tls: 1234
#2 local_getpid: 0
#2 local_getpid: 0
#3 local_getpid: 0
#3 local_getpid: 0
#3 my own tls: 1234
#2 my own tls: 1234
#0 local_getpid: 0
#0 local_getpid: 0
#0 my own tls: 1234
Has your glibc been built with --enable-bind-now?
Thanks,
Florian
next prev parent reply other threads:[~2019-06-21 11:53 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-17 18:06 Baojun Wang
2019-06-17 18:40 ` Florian Weimer
2019-06-17 18:55 ` Baojun Wang
2019-06-17 18:58 ` Baojun Wang
2019-06-17 19:02 ` Florian Weimer
2019-06-18 4:15 ` Baojun Wang
2019-06-21 11:53 ` Florian Weimer [this message]
2019-06-21 14:11 ` Baojun Wang
2019-06-21 16:11 ` Florian Weimer
2019-06-21 20:23 ` Baojun Wang
2019-07-04 13:22 ` Florian Weimer
2019-07-05 18:21 ` Florian Weimer
2019-07-05 18:26 ` Baojun Wang
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