[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
bug#15793: Bug: linking shared libraries on Cygwin results in undefined
From: |
Richard PALO |
Subject: |
bug#15793: Bug: linking shared libraries on Cygwin results in undefined references to __stack_chck_guard for code compiled with -fstack-protector |
Date: |
Thu, 24 Sep 2015 15:15:57 +0200 |
User-agent: |
Mozilla/5.0 (X11; SunOS i86pc; rv:) Gecko/20100101 Thunderbird/24.8.1 |
Le 02/11/13 23:45, Richard PALO a écrit :
> Le 02/06/10 05:24, Yaakov (Cygwin/X) a écrit :
>> On Sat, 15 May 2010 09:07:49 +0200
>> Bart Van Assche <address@hidden> wrote:
>>> This behavior has been observed with libtool version 2.2.6.
>>
>> Bug confirmed. When code is compiled with -fstack-protector{,-all},
>> GCC "emits extra code to check for buffer overflows, such as stack
>> smashing attacks". This extra code uses symbols from libssp, and
>> therefore (at least) Cygwin's GCC specs contain:
>>
>> *link_ssp:
>> %{fstack-protector|fstack-protector-all:-lssp_nonshared -lssp}
>>
>> Therefore, when libtool fails to pass -fstack-protector{,-all} at link
>> stage, the link fails.
>>
>> Patch attached. (Yes, I have a copyright assignment on file.)
>>
>>
>> Yaakov
>> Cygwin/X
>>
>
> I've done some limited testing of this patch on a SunOS distro with
> pkgsrc, and it certainly helps a number of cases since it is gcc that
> generates the necessary '-lssp_nonshared -lssp' libs for linking (at
> least in absence of '-nostdlib').
>
> Please include in the upcoming version.
>
>
>
>
I'd like to propose a slight modification this which, in addition, seems to get
over the
issue (at least on solaris) of c++ shared libraries linking '-nostdlib'.
This could easily be adapted for other hosts using g++. Note, it is harmless if
'-dumpspecs'
or no spec with fstack-protector* is available.
It appears there was no warm welcome in tossing the '-nostdlib' setup for g++
shared libraries
for solaris, so this seems to be a reasonable workaround.
--
Richard PALO
0001-workaround-for-nostdlib-with-fstack-protector-on-sol.patch
Description: Text Data
[Prev in Thread] |
Current Thread |
[Next in Thread] |
- bug#15793: Bug: linking shared libraries on Cygwin results in undefined references to __stack_chck_guard for code compiled with -fstack-protector,
Richard PALO <=