Re: [Valgrind-developers] Why -Wl, -z, interpose, -z, initfirst for valgrind on Linux?

[Tom H. <to...@co...>]

On 22/09/17 09:33, Ivo Raisr wrote:
> 2017-09-22 7:24 GMT+02:00 John Reiser <jr...@bi...>:
>> What is the purpose of the bits DF_1_INTERPOSE and DF_1_INITFIRST that are
>> set in
>> the DT_FLAGS_1 word of the Dynamic section of files
>>          $PREFIX/lib/valgrind/vgpreload_$TOOL-$ARCH-linux.so
>> for which the ultimate source is:
>>      $ grep -e -z, Makefile*
>>      Makefile.all.am:PRELOAD_LDFLAGS_COMMON_LINUX  = -nodefaultlibs -shared
>> -Wl,-z,interpose,-z,initfirst
>>      Makefile.all.am:PRELOAD_LDFLAGS_COMMON_SOLARIS = -nodefaultlibs -shared
>> -Wl,-z,interpose,-z,initfirst
>>      Makefile.tool.am:TOOL_LDFLAGS_ARM_LINUX += -Wl,-z,noexecstack
>>
>> Which particular symbols are those flags designed to affect?
> 
> I can only add that Solaris followed Linux lead here.
> I tried to remove the -z flags on Solaris and did not observe problems...

They appear to go all the way back to commit 918c3a7b7e0 by Jeremy in 
2003 so I suspect the reason for them is long since forgotten...

Tom

-- 
Tom Hughes (to...@co...)
http://compton.nu/