Re: PING^4: [PATCH] Use dlsym to check if libdl is needed for plugin

[H.J. Lu]

On Mon, Apr 16, 2018 at 3:08 PM, Alexandre Oliva  wrote:
> On Apr  3, 2018, "H.J. Lu"  wrote:
>
>> On Mon, Mar 26, 2018 at 4:10 AM, H.J. Lu  wrote:
>>> On Wed, Mar 14, 2018 at 4:41 AM, H.J. Lu  wrote:
 On Wed, Feb 21, 2018 at 3:02 AM, H.J. Lu  wrote:
> On Wed, Oct 18, 2017 at 5:25 PM, H.J. Lu  wrote:
>> * plugins.m4 (AC_PLUGINS): Use dlsym to check if libdl is needed.
>
> This is ok, thanks

Thanks.

 PING.
>
>>> PING.
>
>> PING.
>
> Sorry about the delay.  Next time, I suggest supplying a link to the
> patch in the archives.  Speaking only for myself, I can say it would

Will do.

> have kept me on track a few times I set out to search for and review
> this one patch, got distracted by something else and ended up not
> reviewing it ;-)
>


-- 
H.J.

Re: PING^4: [PATCH] Use dlsym to check if libdl is needed for plugin

[Alexandre Oliva]

On Apr  3, 2018, "H.J. Lu"  wrote:

> On Mon, Mar 26, 2018 at 4:10 AM, H.J. Lu  wrote:
>> On Wed, Mar 14, 2018 at 4:41 AM, H.J. Lu  wrote:
>>> On Wed, Feb 21, 2018 at 3:02 AM, H.J. Lu  wrote:
 On Wed, Oct 18, 2017 at 5:25 PM, H.J. Lu  wrote:
> * plugins.m4 (AC_PLUGINS): Use dlsym to check if libdl is needed.

This is ok, thanks

>>> PING.

>> PING.

> PING.

Sorry about the delay.  Next time, I suggest supplying a link to the
patch in the archives.  Speaking only for myself, I can say it would
have kept me on track a few times I set out to search for and review
this one patch, got distracted by something else and ended up not
reviewing it ;-)

-- 
Alexandre Oliva, freedom fighterhttp://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist|Red Hat Brasil GNU Toolchain Engineer

PING^4: [PATCH] Use dlsym to check if libdl is needed for plugin

[H.J. Lu]

On Mon, Mar 26, 2018 at 4:10 AM, H.J. Lu  wrote:
> On Wed, Mar 14, 2018 at 4:41 AM, H.J. Lu  wrote:
>> On Wed, Feb 21, 2018 at 3:02 AM, H.J. Lu  wrote:
>>> On Wed, Oct 18, 2017 at 5:25 PM, H.J. Lu  wrote:
 config/plugins.m4 has

  if test "$plugins" = "yes"; then
 AC_SEARCH_LIBS([dlopen], [dl])
   fi

 Plugin uses dlsym, but libasan.so only intercepts dlopen, not dlsym:

 [hjl@gnu-tools-1 binutils-text]$ nm -D /lib64/libasan.so.4| grep " dl"
 00038580 W dlclose
  U dl_iterate_phdr
 0004dc50 W dlopen
  U dlsym
  U dlvsym
 [hjl@gnu-tools-1 binutils-text]$

 Testing dlopen for libdl leads to false negative when -fsanitize=address
 is used.  It results in link failure:

 ../bfd/.libs/libbfd.a(plugin.o): undefined reference to symbol 
 'dlsym@@GLIBC_2.16'

 dlsym should be used to check if libdl is needed for plugin.

 OK for master?

 H.J.
 ---
 config/

 * plugins.m4 (AC_PLUGINS): Use dlsym to check if libdl is needed.

>>
>>
>> PING.
>>
>
> PING.
>

PING.

-- 
H.J.