From: Alexander Monakov <amonakov@ispras.ru>
To: Jakub Jelinek <jakub@redhat.com>
Cc: Jeff Law <law@redhat.com>,
gcc-patches@gcc.gnu.org, Rich Felker <dalias@libc.org>
Subject: Re: [PATCH] Expand PIC calls without PLT with -fno-plt
Date: Wed, 06 May 2015 16:44:00 -0000 [thread overview]
Message-ID: <alpine.LNX.2.11.1505061939240.22867@monopod.intra.ispras.ru> (raw)
In-Reply-To: <20150506154554.GZ1751@tucnak.redhat.com>
On Wed, 6 May 2015, Jakub Jelinek wrote:
> The linker would know very well what kind of relocations are used for
> particular PLT slot, and for the new relocations which would resolve to the
> address of the .got.plt slot it could just tweak corresponding 3rd insn
> in the slot, to not jump to first plt slot - 16, but a few bytes before that
> that would just load the address of _G_O_T_ into %ebx and then fallthru
> into the 0x4c2b7310 snippet above. The lazy binding would be a few ticks
> slower in that case, but no requirement on %ebx to contain _G_O_T_.
No, %ebx is callee-saved, so you can't outright overwrite it in the PLT stub.
Alexander
next prev parent reply other threads:[~2015-05-06 16:44 UTC|newest]
Thread overview: 106+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-05-04 16:38 PIC calls without PLT, generic implementation Alexander Monakov
2015-05-04 16:38 ` [PATCH i386] Allow sibcalls in no-PLT PIC Alexander Monakov
2015-05-15 16:37 ` Alexander Monakov
2015-05-15 16:48 ` H.J. Lu
2015-05-15 20:08 ` Jan Hubicka
2015-05-15 20:23 ` H.J. Lu
2015-05-15 20:35 ` Rich Felker
2015-05-15 20:37 ` H.J. Lu
2015-05-15 20:45 ` Rich Felker
2015-05-15 22:16 ` H.J. Lu
2015-05-15 23:14 ` Jan Hubicka
2015-05-15 23:30 ` H.J. Lu
2015-05-15 23:35 ` H.J. Lu
2015-05-15 23:44 ` H.J. Lu
2015-05-16 0:18 ` Rich Felker
2015-05-16 14:33 ` H.J. Lu
2015-05-16 19:03 ` H.J. Lu
2015-05-16 19:32 ` Rich Felker
2015-05-16 23:23 ` H.J. Lu
2015-05-15 23:49 ` Rich Felker
2015-05-19 14:48 ` Michael Matz
2015-05-19 15:11 ` Jeff Law
2015-05-19 16:03 ` Michael Matz
2015-05-19 19:11 ` Rich Felker
2015-05-19 18:08 ` Rich Felker
2015-05-19 19:03 ` Richard Henderson
2015-05-19 19:10 ` H.J. Lu
2015-05-19 19:17 ` Richard Henderson
2015-05-19 19:20 ` H.J. Lu
2015-05-19 19:54 ` Richard Henderson
2015-05-19 20:27 ` Rich Felker
2015-05-19 20:44 ` H.J. Lu
2015-05-19 21:28 ` Rich Felker
2015-05-20 0:52 ` H.J. Lu
2015-05-20 1:09 ` Rich Felker
2015-05-22 19:32 ` Richard Henderson
2015-05-19 19:48 ` Rich Felker
2015-05-19 20:16 ` Richard Henderson
2015-05-20 12:13 ` Michael Matz
2015-05-20 12:40 ` H.J. Lu
2015-05-20 14:17 ` Rich Felker
2015-05-20 14:33 ` Michael Matz
2015-05-18 18:25 ` Alexander Monakov
2015-05-18 19:03 ` Jan Hubicka
2015-05-04 16:38 ` [PATCH] Expand PIC calls without PLT with -fno-plt Alexander Monakov
2015-05-04 17:34 ` Jeff Law
2015-05-04 17:40 ` Jakub Jelinek
2015-05-04 17:42 ` Jeff Law
2015-05-06 3:08 ` Rich Felker
2015-05-10 17:07 ` Jan Hubicka
2015-05-06 15:25 ` Alexander Monakov
2015-05-06 15:46 ` Jakub Jelinek
2015-05-06 15:55 ` Jeff Law
2015-05-06 16:44 ` Alexander Monakov [this message]
2015-05-06 17:35 ` Rich Felker
2015-05-06 18:26 ` H.J. Lu
2015-05-06 18:37 ` Rich Felker
2015-05-06 18:45 ` H.J. Lu
2015-05-06 19:01 ` Rich Felker
2015-05-06 19:05 ` H.J. Lu
2015-05-06 19:18 ` Rich Felker
2015-05-06 19:24 ` H.J. Lu
2015-05-11 11:48 ` Michael Matz
2015-05-11 14:20 ` Rich Felker
2015-05-07 18:22 ` Jeff Law
2015-05-07 19:13 ` H.J. Lu
2015-05-10 16:59 ` Jan Hubicka
2015-05-11 20:36 ` Jeff Law
2015-05-11 20:55 ` H.J. Lu
2015-05-11 22:13 ` Jan Hubicka
2015-06-22 15:52 ` Jiong Wang
2015-06-22 18:18 ` Alexander Monakov
2015-06-23 8:41 ` Ramana Radhakrishnan
2015-06-23 10:43 ` Alexander Monakov
2015-06-23 13:28 ` Jeff Law
2015-07-16 10:37 ` [AArch64] Tighten direct call pattern to repair -fno-plt Jiong Wang
2015-07-16 10:47 ` Alexander Monakov
2015-07-16 10:48 ` Jiong Wang
2015-07-21 12:52 ` [AArch64][sibcall]Tighten " Jiong Wang
2015-08-04 9:50 ` James Greenhalgh
2015-08-06 16:18 ` [COMMITTED][AArch64][sibcall]Tighten " Jiong Wang
2015-08-07 8:22 ` James Greenhalgh
2015-08-07 13:28 ` Jiong Wang
2015-08-04 9:50 ` [AArch64] Tighten " James Greenhalgh
2015-08-06 16:16 ` [COMMITTED][AArch64] " Jiong Wang
2015-05-04 16:38 ` [PATCH i386] PR65753: allow PIC tail calls via function pointers Alexander Monakov
2015-05-10 16:37 ` Jan Hubicka
2015-05-11 16:11 ` Alexander Monakov
2015-05-04 16:38 ` [RFC PATCH] ira: accept loads via argp rtx in validate_equiv_mem Alexander Monakov
2015-05-04 17:37 ` Jeff Law
2015-05-04 16:38 ` [PATCH i386] Extend sibcall peepholes to allow source in %eax Alexander Monakov
2015-05-10 16:54 ` Jan Hubicka
2015-05-11 17:50 ` Alexander Monakov
2015-05-11 18:00 ` Jan Hubicka
2015-05-11 19:46 ` Uros Bizjak
2015-05-11 19:48 ` Jeff Law
2015-05-11 20:16 ` Jan Hubicka
2015-05-13 19:05 ` Alexander Monakov
2015-05-13 20:04 ` Jan Hubicka
2015-05-14 17:36 ` Alexander Monakov
2015-05-04 16:38 ` [PATCH i386] Move CLOBBERED_REGS earlier in register class list Alexander Monakov
2015-05-10 16:44 ` Jan Hubicka
2015-05-10 17:51 ` Uros Bizjak
2015-05-10 18:09 ` Uros Bizjak
2015-05-11 16:26 ` Alexander Monakov
2015-05-11 16:30 ` Uros Bizjak
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