* Re: Global addressing [not found] <oru1ybbtoo.fsf@free.redhat.lsd.ic.unicamp.br> @ 2001-09-10 14:28 ` Joy Mukherjee 2001-09-13 17:36 ` Alexandre Oliva 0 siblings, 1 reply; 10+ messages in thread From: Joy Mukherjee @ 2001-09-10 14:28 UTC (permalink / raw) To: Alexandre Oliva; +Cc: gcc, gcc-help Hi! Just one more thing to ask - Is there any way I can get the beginning and end addresses of the Global Offset Table ? The tag _GLOBAL_OFFSET_TABLE_ points to somewhere in the middle of the .got section so that both +ve and -ve offsets are possible , but I want to know the exact addresses where the GOT begins and ends . How can I do that ? Thank you so much for all your help . Joy ****************************************************************************** JOY MUKHERJEE OFFICE: GRADUATE STUDENT DEPTT. OF COMPUTER SCIENCE MCBRYDE HALL VIRGINIA TECH BLACKSBURG , VA - 24061 PH. - (540) 231 5853 RESIDENCE: 1211 PROGRESS STREET APT. # 7100 F BLACKSBURG , VA - 24060 USA. PH. - (540) 951 7771 Other e-mails : jmukherj@vt.edu jmjee@lycos.com ****************************************************************************** On 10 Sep 2001, Alexandre Oliva wrote: > On Sep 6, 2001, Joy Mukherjee <jmukherj@csgrad.cs.vt.edu> wrote: > > > But is there any other way also to force indexed global > > addressing ? > > I don't think there's any other mostly target-independent flag. Some > targets may offer flags to do it, but none of those I'm familiar > with do. > > -- > Alexandre Oliva Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/ > Red Hat GCC Developer aoliva@{cygnus.com, redhat.com} > CS PhD student at IC-Unicamp oliva@{lsd.ic.unicamp.br, gnu.org} > Free Software Evangelist *Please* write to mailing lists, not to me > > ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Global addressing 2001-09-10 14:28 ` Global addressing Joy Mukherjee @ 2001-09-13 17:36 ` Alexandre Oliva 2001-09-13 19:27 ` Start and end of the GOT Joy Mukherjee 0 siblings, 1 reply; 10+ messages in thread From: Alexandre Oliva @ 2001-09-13 17:36 UTC (permalink / raw) To: Joy Mukherjee; +Cc: gcc, gcc-help On Sep 10, 2001, Joy Mukherjee <jmukherj@csgrad.cs.vt.edu> wrote: > I want to know the exact addresses where the GOT begins and ends. > How can I do that ? Look for `.got' in the output of `objdump -h'. In case you want to do it at run-time, it depends on the platform. -- Alexandre Oliva Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/ Red Hat GCC Developer aoliva@{cygnus.com, redhat.com} CS PhD student at IC-Unicamp oliva@{lsd.ic.unicamp.br, gnu.org} Free Software Evangelist *Please* write to mailing lists, not to me ^ permalink raw reply [flat|nested] 10+ messages in thread
* Start and end of the GOT 2001-09-13 17:36 ` Alexandre Oliva @ 2001-09-13 19:27 ` Joy Mukherjee 2001-09-14 7:44 ` Alexandre Oliva 0 siblings, 1 reply; 10+ messages in thread From: Joy Mukherjee @ 2001-09-13 19:27 UTC (permalink / raw) To: Alexandre Oliva; +Cc: gcc, gcc-help Alexandre, Thanks again for your help . I do want to do it at runtime . I am working on Red Hat Linux (glibc), intel x86, gcc 2.96 ( this I am not very sure ) . Can you please tell me how this thing might work at runtime ? Thanks again . Joy. Joy Mukherjee Graduate Student, Deptt. of CS, Virginia Tech, Blacksburg,VA - 24061. On 13 Sep 2001, Alexandre Oliva wrote: > On Sep 10, 2001, Joy Mukherjee <jmukherj@csgrad.cs.vt.edu> wrote: > > > I want to know the exact addresses where the GOT begins and ends. > > How can I do that ? > > Look for `.got' in the output of `objdump -h'. > > In case you want to do it at run-time, it depends on the platform. > > -- > Alexandre Oliva Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/ > Red Hat GCC Developer aoliva@{cygnus.com, redhat.com} > CS PhD student at IC-Unicamp oliva@{lsd.ic.unicamp.br, gnu.org} > Free Software Evangelist *Please* write to mailing lists, not to me > > ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Start and end of the GOT 2001-09-13 19:27 ` Start and end of the GOT Joy Mukherjee @ 2001-09-14 7:44 ` Alexandre Oliva 2001-09-14 17:33 ` Joy Mukherjee 0 siblings, 1 reply; 10+ messages in thread From: Alexandre Oliva @ 2001-09-14 7:44 UTC (permalink / raw) To: Joy Mukherjee; +Cc: gcc, gcc-help On Sep 13, 2001, Joy Mukherjee <jmukherj@csgrad.cs.vt.edu> wrote: > Thanks again for your help . I do want to do it at runtime . I am > working on Red Hat Linux (glibc), intel x86 AFAIK, all you have to do is to get the value of ebx in a function compiled with -fPIC. -- Alexandre Oliva Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/ Red Hat GCC Developer aoliva@{cygnus.com, redhat.com} CS PhD student at IC-Unicamp oliva@{lsd.ic.unicamp.br, gnu.org} Free Software Evangelist *Please* write to mailing lists, not to me ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Start and end of the GOT 2001-09-14 7:44 ` Alexandre Oliva @ 2001-09-14 17:33 ` Joy Mukherjee 2001-09-17 15:17 ` Richard Henderson 0 siblings, 1 reply; 10+ messages in thread From: Joy Mukherjee @ 2001-09-14 17:33 UTC (permalink / raw) To: Alexandre Oliva; +Cc: gcc, gcc-help True, but %ebx just contains the start address of the GOT. How do I get the END address ? or in other words , how do I get its size ? Thank again for your help . Joy Joy Mukherjee Graduate Student, Deptt. of CS, Virginia Tech, Blacksburg,VA - 24061. On 14 Sep 2001, Alexandre Oliva wrote: > On Sep 13, 2001, Joy Mukherjee <jmukherj@csgrad.cs.vt.edu> wrote: > > > Thanks again for your help . I do want to do it at runtime . I am > > working on Red Hat Linux (glibc), intel x86 > > AFAIK, all you have to do is to get the value of ebx in a function > compiled with -fPIC. > > -- > Alexandre Oliva Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/ > Red Hat GCC Developer aoliva@{cygnus.com, redhat.com} > CS PhD student at IC-Unicamp oliva@{lsd.ic.unicamp.br, gnu.org} > Free Software Evangelist *Please* write to mailing lists, not to me > > ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Start and end of the GOT 2001-09-14 17:33 ` Joy Mukherjee @ 2001-09-17 15:17 ` Richard Henderson 2001-09-17 15:36 ` Jakub Jelinek 0 siblings, 1 reply; 10+ messages in thread From: Richard Henderson @ 2001-09-17 15:17 UTC (permalink / raw) To: Joy Mukherjee; +Cc: Alexandre Oliva, gcc, gcc-help On Fri, Sep 14, 2001 at 08:33:21PM -0400, Joy Mukherjee wrote: > True, but %ebx just contains the start address of the GOT. How do I get > the END address ? or in other words , how do I get its size ? You can't. r~ ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Start and end of the GOT 2001-09-17 15:17 ` Richard Henderson @ 2001-09-17 15:36 ` Jakub Jelinek 2001-09-17 15:53 ` Richard Henderson 0 siblings, 1 reply; 10+ messages in thread From: Jakub Jelinek @ 2001-09-17 15:36 UTC (permalink / raw) To: Richard Henderson, Joy Mukherjee, Alexandre Oliva, gcc, gcc-help On Mon, Sep 17, 2001 at 03:17:52PM -0700, Richard Henderson wrote: > On Fri, Sep 14, 2001 at 08:33:21PM -0400, Joy Mukherjee wrote: > > True, but %ebx just contains the start address of the GOT. How do I get > > the END address ? or in other words , how do I get its size ? > > You can't. Well, assuming IA-32 and nobody playing with linker scripts, end will be _DYNAMIC because .sdata2/.sbss2 sections are usually not used on IA-32. Jakub ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Start and end of the GOT 2001-09-17 15:36 ` Jakub Jelinek @ 2001-09-17 15:53 ` Richard Henderson 2001-09-17 16:09 ` H . J . Lu 0 siblings, 1 reply; 10+ messages in thread From: Richard Henderson @ 2001-09-17 15:53 UTC (permalink / raw) To: Jakub Jelinek; +Cc: Joy Mukherjee, Alexandre Oliva, gcc, gcc-help On Tue, Sep 18, 2001 at 12:39:15AM +0200, Jakub Jelinek wrote: > Well, assuming IA-32 and nobody playing with linker scripts, end will be > _DYNAMIC because .sdata2/.sbss2 sections are usually not used on IA-32. I urge you not to rely on this. The NetBSD ld.so self-relocation code does (did, anyway) this, and it is the reason that .dynamic is still where it is. Personally, I think this is a bug in the NetBSD ld.so and should have been fixed rather than wasting some 400 bytes of the small data area. r~ ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Start and end of the GOT 2001-09-17 15:53 ` Richard Henderson @ 2001-09-17 16:09 ` H . J . Lu 2001-09-17 16:22 ` Richard Henderson 0 siblings, 1 reply; 10+ messages in thread From: H . J . Lu @ 2001-09-17 16:09 UTC (permalink / raw) To: Richard Henderson, Jakub Jelinek, Joy Mukherjee, Alexandre Oliva, gcc, gcc-help On Mon, Sep 17, 2001 at 03:53:33PM -0700, Richard Henderson wrote: > On Tue, Sep 18, 2001 at 12:39:15AM +0200, Jakub Jelinek wrote: > > Well, assuming IA-32 and nobody playing with linker scripts, end will be > > _DYNAMIC because .sdata2/.sbss2 sections are usually not used on IA-32. > > I urge you not to rely on this. > > The NetBSD ld.so self-relocation code does (did, anyway) this, and it > is the reason that .dynamic is still where it is. Personally, I think > this is a bug in the NetBSD ld.so and should have been fixed rather > than wasting some 400 bytes of the small data area. > Does that mean Linux also wastes 400 bytes? I'd like to get them back for Linux. H.J. ^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: Start and end of the GOT 2001-09-17 16:09 ` H . J . Lu @ 2001-09-17 16:22 ` Richard Henderson 0 siblings, 0 replies; 10+ messages in thread From: Richard Henderson @ 2001-09-17 16:22 UTC (permalink / raw) To: H . J . Lu; +Cc: Jakub Jelinek, Joy Mukherjee, Alexandre Oliva, gcc, gcc-help On Mon, Sep 17, 2001 at 04:08:37PM -0700, H . J . Lu wrote: > Does that mean Linux also wastes 400 bytes? I'd like to get them back > for Linux. Yes, but do not uglify the linker scripts even more with such port-specific hacks. 400 bytes isn't worth that. r~ ^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2001-09-17 16:22 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
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[not found] <oru1ybbtoo.fsf@free.redhat.lsd.ic.unicamp.br>
2001-09-10 14:28 ` Global addressing Joy Mukherjee
2001-09-13 17:36 ` Alexandre Oliva
2001-09-13 19:27 ` Start and end of the GOT Joy Mukherjee
2001-09-14 7:44 ` Alexandre Oliva
2001-09-14 17:33 ` Joy Mukherjee
2001-09-17 15:17 ` Richard Henderson
2001-09-17 15:36 ` Jakub Jelinek
2001-09-17 15:53 ` Richard Henderson
2001-09-17 16:09 ` H . J . Lu
2001-09-17 16:22 ` Richard Henderson
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