RISC-V: ABI Implementation

This patch contains code that needs to directly know about the RISC-V
ABI, which is specified in a work-in-progress psABI document:

  https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md

This is meant to contain all the RISC-V code that needs to explicitly
name registers or manage in-memory structure layout.  This does not
contain any of the Linux-specific code.

2018-01-29  Palmer Dabbelt  <palmer@sifive.com>

        * sysdeps/riscv/__longjmp.S: New file.
        * sysdeps/riscv/backtrace.c: Likewise.
        * sysdeps/riscv/bits/endian.h: Likewise.
        * sysdeps/riscv/bits/setjmp.h: Likewise.
        * sysdeps/riscv/bits/wordsize.h: Likewise.
        * sysdeps/riscv/bsd-_setjmp.c: Likewise.
        * sysdeps/riscv/bsd-setjmp.c: Likewise.
        * sysdeps/riscv/dl-trampoline.S: Likewise.
        * sysdeps/riscv/gccframe.h: Likewise.
        * sysdeps/riscv/jmpbuf-offsets.h: Likewise.
        * sysdeps/riscv/jmpbuf-unwind.h: Likewise.
        * sysdeps/riscv/machine-gmon.h: Likewise.
        * sysdeps/riscv/memusage.h: Likewise.
        * sysdeps/riscv/setjmp.S: Likewise.
        * sysdeps/riscv/sys/asm.h: Likewise.
        * sysdeps/riscv/tls-macros.h: Likewise.

1 files changed, 47 insertions, 0 deletions

diff --git a/sysdeps/riscv/ldsodefs.h b/sysdeps/riscv/ldsodefs.h
new file mode 100644
index 0000000000..c032b73a9c
--- /dev/null
+++ b/sysdeps/riscv/ldsodefs.h
@@ -0,0 +1,47 @@
+/* Run-time dynamic linker data structures for loaded ELF shared objects.
+   Copyright (C) 2011-2018 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
+   <http://www.gnu.org/licenses/>.  */
+
+#ifndef _RISCV_LDSODEFS_H
+#define _RISCV_LDSODEFS_H 1
+
+#include <elf.h>
+
+struct La_riscv_regs;
+struct La_riscv_retval;
+
+#define ARCH_PLTENTER_MEMBERS						\
+    ElfW(Addr) (*riscv_gnu_pltenter) (ElfW(Sym) *, unsigned int,	\
+				      uintptr_t *, uintptr_t *,		\
+				      const struct La_riscv_regs *,	\
+				      unsigned int *, const char *name,	\
+				      long int *framesizep);
+
+#define ARCH_PLTEXIT_MEMBERS						\
+    unsigned int (*riscv_gnu_pltexit) (ElfW(Sym) *, unsigned int,	\
+				       uintptr_t *, uintptr_t *,	\
+				       const struct La_riscv_regs *,	\
+				       struct La_riscv_retval *,	\
+				       const char *);
+
+/* The RISC-V ABI specifies that the dynamic section has to be read-only.  */
+
+#define DL_RO_DYN_SECTION 1
+
+#include_next <ldsodefs.h>
+
+#endif