but this is a problem with the library itself, not the checkin. Sun On Tue, Aug 3, 2010 at 8:55 PM, Peng Yuan <yingbo....@gmail.com> wrote: > If libopen64rt_shared.a can be used for executable except for shared > library, I'll support the checkin. Not perfect, but it can work for the > current trunk. Otherwise we must notice the PIE issue. > > I just explain the PIE linking. I don't konw the function of libopen64rt.a > and libopen64rt.a. Why does open64 need them? Why memset.o and cacheinfo.o > are removed from libopen64rt_shared.a? > > All objects participating in -pie link must be compiled with -fPIE. PIE is > not PIC. PIE is for executable (-pie link) and PIC is for shared library > (-shared link). So we cannot replace PIE objects with PIC objects. > > It is a mere coincidence that there is no linker error with > libopen64rt_shared.a at -fPIE. Only cacheinfo.o has dynamic relocation info > (GOT/PLT) at PIE/PIC, but it is removed from libopen64rt_shared.a (see > below). > > The generation of the two libraries: > ar cru libopen64rt.a fastcopy_gh.o malloc_opt.o memset.o cacheinfo.o > ar cru libopen64rt_shared.a fastcopy_gh.o malloc_opt.o memset.o cacheinfo.o > ar dv libopen64rt_shared.a memset.o cacheinfo.o > > The two libraries use the same objects. Note objects in libopen64rt_shared.a > are NOT compiled with -fPIC. > > Why "non -fPIC" libopen64rt_shared.a also works for -shared? > Just a mere coincidence... I look through malloc_opt.c and fastcopy_gh.s > which constitute libopen64rt_shared.a. The codes are simple and have no > global symbols, so they don't need GOT/PLT and there is no difference > between -fPIC and "non -fPIC". Note if we add new functions to the library, > we must pay attention to this issue! > > > On Wed, Aug 4, 2010 at 6:48 AM, Steve Ellcey <s...@cup.hp.com> wrote: >> >> This patch is my proposed fix for bug 577, The problem is that when >> linking a program using the -pie (-fPIE, -fpie) option to create a >> position independent executable we link in libopen64rt.a which contains >> non-PIC code and this causes us to get a link-time error. >> >> My fix is to link in libopen64rt_shared.a instead of libopen64rt.a when >> linking PIE code since the code in libopen64rt_shared.a is built with >> the -fPIC option. We already link in libopen64rt_shared.a instead of >> libopen64rt.a when building shared libraries. >> >> I tested the patch on a small test case that calls bzero (one of the >> functions defined in libopen64rt) and verified that it fixes the bug on >> x86 and since the libopen64rt libraries are only used for x86 targets >> this won't affect any other targets. >> >> Can a gatekeeper approve this patch? >> >> Steve Ellcey >> s...@cup.hp.com >> >> >> Defect report: >> >> http://bugs.open64.net/show_bug.cgi?id=577 >> >> >> Patch: >> >> Index: osprey/driver/phases.c >> =================================================================== >> --- osprey/driver/phases.c (revision 3298) >> +++ osprey/driver/phases.c (working copy) >> @@ -2124,7 +2124,8 @@ add_final_ld_args (string_list_t *args, >> // Bug 3995. >> if (!option_was_seen(O_fno_fast_stdlib) && >> !option_was_seen(O_nolibopen64rt)) { // bug 9611 >> - if (option_was_seen(O_shared)) { >> + if (option_was_seen(O_shared) || option_was_seen(O_pie) || >> + option_was_seen(O_fpie) || option_was_seen(O_fPIE)) { >> add_library(args, "open64rt_shared"); >> } else { >> add_library(args, "open64rt"); >> >> >> ------------------------------------------------------------------------------ >> The Palm PDK Hot Apps Program offers developers who use the >> Plug-In Development Kit to bring their C/C++ apps to Palm for a share >> of $1 Million in cash or HP Products. Visit us here for more details: >> http://p.sf.net/sfu/dev2dev-palm >> _______________________________________________ >> Open64-devel mailing list >> Open64-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/open64-devel > > > > -- > Regards, > Peng Yuan (袁鹏) > Performance that will make your eyes water! > > ------------------------------------------------------------------------------ > The Palm PDK Hot Apps Program offers developers who use the > Plug-In Development Kit to bring their C/C++ apps to Palm for a share > of $1 Million in cash or HP Products. Visit us here for more details: > http://p.sf.net/sfu/dev2dev-palm > _______________________________________________ > Open64-devel mailing list > Open64-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/open64-devel > >
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