RISC-V: Linux ABI

Linux-specific code that is required for maintaining ABI compatibility.
This doesn't contain the actual system call interface, that is split out
in order to avoid having a patch that's too big.

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

        * sysdeps/riscv/nptl/pthread-offsets.h: New file.
        * sysdeps/riscv/nptl/pthreaddef.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/bits/fcntl.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/bits/mman.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/bits/sigcontext.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/dl-cache.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/flush-icache.c: Likewise.
        * sysdeps/unix/sysv/linux/riscv/getcontext.S: Likewise.
        * sysdeps/unix/sysv/linux/riscv/init-first.c: Likewise.
        * sysdeps/unix/sysv/linux/riscv/libc-vdso.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/makecontext.c: Likewise.
        * sysdeps/unix/sysv/linux/riscv/readelflib.c: Likewise.
        * sysdeps/unix/sysv/linux/riscv/register-dump.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/setcontext.S: Likewise.
        * sysdeps/unix/sysv/linux/riscv/sigcontextinfo.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/swapcontext.S: Likewise.
        * sysdeps/unix/sysv/linux/riscv/sys/cachectl.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/sys/procfs.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/sys/ucontext.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/sys/user.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/ucontext-macros.h: Likewise.
        * sysdeps/unix/sysv/linux/riscv/ucontext_i.sym: Likewise.

1 files changed, 75 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/riscv/dl-cache.h b/sysdeps/unix/sysv/linux/riscv/dl-cache.h
new file mode 100644
index 0000000000..cbd6ef5e09
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/riscv/dl-cache.h
@@ -0,0 +1,75 @@
+/* Support for reading /etc/ld.so.cache files written by Linux ldconfig.
+   Copyright (C) 2003-2018 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/>.  */
+
+#include <ldconfig.h>
+
+/* For now we only support the natural XLEN ABI length on all targets, so the
+   only bits that need to go into ld.so.cache are the FLEG ABI length.  */
+#if defined __riscv_float_abi_double
+# define _DL_CACHE_DEFAULT_ID    (FLAG_RISCV_FLOAT_ABI_DOUBLE | FLAG_ELF_LIBC6)
+#else
+# define _DL_CACHE_DEFAULT_ID    (FLAG_RISCV_FLOAT_ABI_SOFT | FLAG_ELF_LIBC6)
+#endif
+
+#define _dl_cache_check_flags(flags)		    			\
+  ((flags) == _DL_CACHE_DEFAULT_ID)
+
+/* If given a path to one of our library directories, adds every library
+   directory via add_dir (), otherwise just adds the giver directory.  On
+   RISC-V, libraries can be found in paths ending in:
+     - /lib64/lp64d
+     - /lib64/lp64
+     - /lib (only ld.so)
+   so this will add all of those paths.
+
+   According to Joseph Myers:
+       My reasoning for that would be: generic autoconf-configured (etc.)
+       software may only know about using the lib directory, so you want the
+       lib directory to be searched regardless of the ABI - but it's also
+       useful to be able to e.g. list /usr/local/lib in /etc/ld.so.conf for all
+       architectures and have that automatically imply /usr/local/lib64/lp64d
+       etc. so that libraries can be found that come from software that does
+       use the ABI-specific directories.  */
+#define add_system_dir(dir) 						\
+  do							    		\
+    {									\
+      size_t len = strlen (dir);					\
+      char path[len + 9];						\
+      memcpy (path, dir, len + 1);					\
+      if (len >= 12 && ! memcmp(path + len - 12, "/lib64/lp64d", 12))	\
+	{								\
+	  len -= 8;							\
+	  path[len] = '\0';						\
+	}								\
+      if (len >= 11 && ! memcmp(path + len - 11, "/lib64/lp64", 11))	\
+	{								\
+	  len -= 7;							\
+	  path[len] = '\0';						\
+	}								\
+      add_dir (path);							\
+      if (len >= 4 && ! memcmp(path + len - 4, "/lib", 4))		\
+	{								\
+	  memcpy (path + len, "64/lp64d", 9);				\
+	  add_dir (path);						\
+	  memcpy (path + len, "64/lp64", 8);				\
+	  add_dir (path);						\
+	}								\
+    } while (0)
+
+
+#include_next <dl-cache.h>