From: Vineet Gupta via Libc-alpha <libc-alpha@sourceware.org>
To: libc-alpha@sourceware.org
Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com>,
linux-snps-arc@lists.infradead.org
Subject: [PATCH 2/2] ARC/dl-runtime helper macros
Date: Fri, 29 May 2020 14:21:42 -0700 [thread overview]
Message-ID: <20200529212142.19869-2-vgupta@synopsys.com> (raw)
In-Reply-To: <20200529212142.19869-1-vgupta@synopsys.com>
This is purely for review purposes to attest the interface defined
in prior patch
---
sysdeps/arc/dl-runtime.h | 42 ++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
create mode 100644 sysdeps/arc/dl-runtime.h
diff --git a/sysdeps/arc/dl-runtime.h b/sysdeps/arc/dl-runtime.h
new file mode 100644
index 000000000000..529d49f5d0a1
--- /dev/null
+++ b/sysdeps/arc/dl-runtime.h
@@ -0,0 +1,42 @@
+/* Helpers for On-demand PLT fixup for shared objects. ARC version.
+ Copyright (C) 2017-2020 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public License as
+ published by the Free Software Foundation; either version 2.1 of the
+ License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library. If not, see
+ <https://www.gnu.org/licenses/>. */
+
+/* PLT jump into resolver passes PC of PLTn, while _dl_fixup expects the
+ address of corresponding .rela.plt entry.
+
+ - @plt0: runtime pc of first plt entry (DT_PLTGOT)
+ - @pltn: runtime pc of plt entry being resolved
+ - @size: size of .plt.rela entry (unused). */
+static inline uintptr_t
+reloc_index (uintptr_t plt0, uintptr_t pltn, size_t size)
+{
+ unsigned long int idx = (unsigned long)pltn - (unsigned long)plt0;
+
+ /* PLT trampoline is 16 bytes. */
+ idx /= 16;
+
+ /* Exclude PLT0 and PLT1. */
+ return idx - 2;
+}
+
+static inline uintptr_t
+reloc_offset (uintptr_t plt0, uintptr_t pltn)
+{
+ size_t sz = sizeof (ElfW(Rela));
+ return reloc_index(plt0, pltn, sz) * sz;
+}
--
2.20.1
prev parent reply other threads:[~2020-05-29 21:21 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-28 19:43 [PATCH] dl-runtime: reloc_{offset, index} now functions arch overide'able Vineet Gupta via Libc-alpha
2020-05-29 12:58 ` [PATCH] dl-runtime: reloc_{offset,index} " Adhemerval Zanella via Libc-alpha
2020-05-29 17:39 ` Vineet Gupta via Libc-alpha
2020-05-29 20:54 ` Adhemerval Zanella via Libc-alpha
2020-05-29 21:21 ` [PATCH 1/2] dl-runtime: reloc_{offset, index} " Vineet Gupta via Libc-alpha
2020-05-29 21:21 ` Vineet Gupta via Libc-alpha [this message]
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