Document new files for Linux i386/ELF port.

Fri Sep  8 16:32:12 1995  Ulrich Drepper  <drepper@gnu.ai.mit.edu>

        * sysdeps/unix/sysv/linux/Implies,
        sysdeps/unix/sysv/linux/Makefile, sysdeps/unix/sysv/linux/Subdirs,
        sysdeps/unix/sysv/linux/accept.S, sysdeps/unix/sysv/linux/adjtime.c,
        sysdeps/unix/sysv/linux/adjtimex.S, sysdeps/unix/sysv/linux/bind.S,
        sysdeps/unix/sysv/linux/connect.S, sysdeps/unix/sysv/linux/direct.h,
        sysdeps/unix/sysv/linux/dl-machine.h, sysdeps/unix/sysv/linux/errnos.h,
        sysdeps/unix/sysv/linux/fork.S, sysdeps/unix/sysv/linux/gethostid.c,
        sysdeps/unix/sysv/linux/gethostname.C,
        sysdeps/unix/sysv/linux/getpeername.S,
        sysdeps/unix/sysv/linux/getpgid.S, sysdeps/unix/sysv/linux/getpgrp.S,
	sysdeps/unix/sysv/linux/getsockname.S,
	sysdeps/unix/sysv/linux/getsockopt.S, sysdeps/unix/sysv/linux/gtty.S,
	sysdeps/unix/sysv/linux/listen.S, sysdeps/unix/sysv/linux/local_lim.h,
	sysdeps/unix/sysv/linux/madvise.c, sysdeps/unix/sysv/linux/msgctl.c,
	sysdeps/unix/sysv/linux/msgget.c, sysdeps/unix/sysv/linux/msgrcv.c,
	sysdeps/unix/sysv/linux/msgsnd.c, sysdeps/unix/sysv/linux/pipe.S,
	sysdeps/unix/sysv/linux/poll.c, sysdeps/unix/sysv/linux/readv.c,
	sysdeps/unix/sysv/linux/recv.S, sysdeps/unix/sysv/linux/recvfrom.S,
	sysdeps/unix/sysv/linux/recvmsg.S, sysdeps/unix/sysv/linux/semctl.c,
	sysdeps/unix/sysv/linux/semget.c, sysdeps/unix/sysv/linux/semop.c,
	sysdeps/unix/sysv/linux/send.S, sysdeps/unix/sysv/linux/sendmsg.S,
	sysdeps/unix/sysv/linux/sendto.S, sysdeps/unix/sysv/linux/setegid.c,
	sysdeps/unix/sysv/linux/seteuid.c, sysdeps/unix/sysv/linux/sethostid.c,
	sysdeps/unix/sysv/linux/setpgid.c, sysdeps/unix/sysv/linux/setpgrp.c,
	sysdeps/unix/sysv/linux/setsid.S, sysdeps/unix/sysv/linux/setsockopt.S,
	sysdeps/unix/sysv/linux/settimeofday.S,
	sysdeps/unix/sysv/linux/shmat.c, sysdeps/unix/sysv/linux/shmctl.c,
	sysdeps/unix/sysv/linux/shmdt.c, sysdeps/unix/sysv/linux/shmget.c,
	sysdeps/unix/sysv/linux/shutdown.S,
	sysdeps/unix/sysv/linux/sigaction.S, sysdeps/unix/sysv/linux/signal.S,
	sysdeps/unix/sysv/linux/sigpending.S, sysdeps/unix/sysv/linux/sigset.h,
	sysdeps/unix/sysv/linux/sockaddrcom.h,
	sysdeps/unix/sysv/linux/socketpair.S, sysdeps/unix/sysv/linux/speed.c,
	sysdeps/unix/sysv/linux/statbuf.h, sysdeps/unix/sysv/linux/stty.S,
	sysdeps/unix/sysv/linux/syscall.h, sysdeps/unix/sysv/linux/sysconf.c,
	sysdeps/unix/sysv/linux/tcdrain.c, sysdeps/unix/sysv/linux/tcflow.c,
	sysdeps/unix/sysv/linux/tcflush.c, sysdeps/unix/sysv/linux/tcgetattr.c,
	sysdeps/unix/sysv/linux/tcsetattr.c,
	sysdeps/unix/sysv/linux/termbits.h, sysdeps/unix/sysv/linux/ualarm.c,
	sysdeps/unix/sysv/linux/ulimit.c, sysdeps/unix/sysv/linux/usleep.c,
	sysdeps/unix/sysv/linux/utsnamelen.h, sysdeps/unix/sysv/linux/vfork.c,
	sysdeps/unix/sysv/linux/wait.c, sysdeps/unix/sysv/linux/wait4.S,
	sysdeps/unix/sysv/linux/waitpid.c, sysdeps/unix/sysv/linux/writev.c:
	New Linux/ELF specific, architecture independent files.

	sysdeps/unix/sysv/linux/i386/Dist,
	sysdeps/unix/sysv/linux/i386/Makefile,
	sysdeps/unix/sysv/linux/i386/brk.S,
	sysdeps/unix/sysv/linux/i386/fcntlbits.h,
	sysdeps/unix/sysv/linux/i386/fpu_control.c,
	sysdeps/unix/sysv/linux/i386/fpu_control.h,
	sysdeps/unix/sysv/linux/i386/fstat.S,
	sysdeps/unix/sysv/linux/i386/fxstat.S,
	sysdeps/unix/sysv/linux/i386/ieee_fpu.c,
	sysdeps/unix/sysv/linux/i386/init-first.S,
	sysdeps/unix/sysv/linux/i386/ipc.S,
	sysdeps/unix/sysv/linux/i386/lstat.S,
	sysdeps/unix/sysv/linux/i386/lxstat.S,
	sysdeps/unix/sysv/linux/i386/mknod.S,
	sysdeps/unix/sysv/linux/i386/mmap.S,
	sysdeps/unix/sysv/linux/i386/sbrk.S,
	sysdeps/unix/sysv/linux/i386/setfpucw.c,
	sysdeps/unix/sysv/linux/i386/signum.h,
	sysdeps/unix/sysv/linux/i386/socket.S,
	sysdeps/unix/sysv/linux/i386/stat.S,
	sysdeps/unix/sysv/linux/i386/syscall.S,
	sysdeps/unix/sysv/linux/i386/sysdep.S,
	sysdeps/unix/sysv/linux/i386/sysdep.h,
	sysdeps/unix/sysv/linux/i386/xmknod.S,
	sysdeps/unix/sysv/linux/i386/xstat.S:
	New Linux i386/ELF specific files.

	sysdeps/unix/sysv/linux/sys/ipc_buf.h,
	sysdeps/unix/sysv/linux/sys/mman.h,
	sysdeps/unix/sysv/linux/sys/msq_buf.h,
	sysdeps/unix/sysv/linux/sys/sem_buf.h,
	sysdeps/unix/sysv/linux/sys/shm_buf.h,
	sysdeps/unix/sysv/linux/sys/socketcall.h,
	sysdeps/unix/sysv/linux/sys/timex.h:
	New Linux/ELF specific, architecture independent header files.

1 files changed, 214 insertions, 0 deletions

diff --git a/sysdeps/unix/sysv/linux/dl-machine.h b/sysdeps/unix/sysv/linux/dl-machine.h
new file mode 100644
index 0000000000..2ed6c670e5
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/dl-machine.h
@@ -0,0 +1,214 @@
+/* Machine-dependent ELF dynamic relocation inline functions.
+   i386/Linux version.
+Copyright (C) 1995 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 Library General Public License as
+published by the Free Software Foundation; either version 2 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
+Library General Public License for more details.
+
+You should have received a copy of the GNU Library General Public
+License along with the GNU C Library; see the file COPYING.LIB.  If
+not, write to the Free Software Foundation, Inc., 675 Mass Ave,
+Cambridge, MA 02139, USA.  */
+
+#define ELF_MACHINE_NAME "i386"
+
+#include <assert.h>
+#include <string.h>
+#include <link.h>
+#include <syscall.h>
+#include <sys/mman.h>
+
+/* Return nonzero iff E_MACHINE is compatible with the running host.  */
+static inline int
+elf_machine_matches_host (Elf32_Half e_machine)
+{
+  switch (e_machine)
+    {
+    case EM_386:
+    case EM_486:
+      return 1;
+    default:
+      return 0;
+    }
+}
+
+
+/* Return the run-time address of the _GLOBAL_OFFSET_TABLE_.
+   Must be inlined in a function which uses global data.  */
+static inline Elf32_Addr *
+elf_machine_got (void)
+{
+  register Elf32_Addr *got asm ("%ebx");
+  return got;
+}
+
+
+/* Return the run-time load address of the shared object.  */
+static inline Elf32_Addr
+elf_machine_load_address (void)
+{
+  Elf32_Addr addr;
+  asm ("	call here\n"
+       "here:	popl %0\n"
+       "	subl $here, %0"
+       : "=r" (addr));
+  return addr;
+}
+/* The `subl' insn above will contain an R_386_32 relocation entry
+   intended to insert the run-time address of the label `here'.
+   This will be the first relocation in the text of the dynamic linker;
+   we skip it to avoid trying to modify read-only text in this early stage.  */
+#define ELF_MACHINE_BEFORE_RTLD_RELOC(dynamic_info) \
+  ++(const Elf32_Rel *) (dynamic_info)[DT_REL]->d_un.d_ptr; \
+  (dynamic_info)[DT_RELSZ]->d_un.d_val -= sizeof (Elf32_Rel)
+
+/* Perform the relocation specified by RELOC and SYM (which is fully resolved).
+   MAP is the object containing the reloc.  */
+
+static inline void
+elf_machine_rel (struct link_map *map,
+		 const Elf32_Rel *reloc,
+		 Elf32_Addr sym_loadaddr, const Elf32_Sym *sym)
+{
+  Elf32_Addr *const reloc_addr = (void *) (map->l_addr + reloc->r_offset);
+  const Elf32_Addr sym_value = sym_loadaddr + sym->st_value;
+
+  switch (ELF32_R_TYPE (reloc->r_info))
+    {
+    case R_386_COPY:
+      memcpy (reloc_addr, (void *) sym_value, sym->st_size);
+      break;
+    case R_386_GLOB_DAT:
+    case R_386_JMP_SLOT:
+      *reloc_addr = sym_value;
+      break;
+    case R_386_32:
+      if (map->l_type == lt_interpreter)
+	{
+	  /* Undo the relocation done here during bootstrapping.  Now we will
+	     relocate it anew, possibly using a binding found in the user
+	     program or a loaded library rather than the dynamic linker's
+	     built-in definitions used while loading those libraries.  */
+	  const Elf32_Sym *const dlsymtab
+	    = (void *) (map->l_addr + map->l_info[DT_SYMTAB]->d_un.d_ptr);
+	  *reloc_addr -= (map->l_addr +
+			  dlsymtab[ELF32_R_SYM (reloc->r_info)].st_value);
+	}
+      *reloc_addr += sym_value;
+      break;
+    case R_386_RELATIVE:
+      if (map->l_type != lt_interpreter) /* Already done in dynamic linker.  */
+	*reloc_addr += map->l_addr;
+      break;
+    case R_386_PC32:
+      *reloc_addr = sym_value - (Elf32_Addr) reloc_addr;
+      break;
+    default:
+      assert (! "unexpected dynamic reloc type");
+      break;
+    }
+}
+
+static inline void
+elf_machine_lazy_rel (struct link_map *map, const Elf32_Rel *reloc)
+{
+  Elf32_Addr *const reloc_addr = (void *) (map->l_addr + reloc->r_offset);
+  switch (ELF32_R_TYPE (reloc->r_info))
+    {
+    case R_386_JMP_SLOT:
+      *reloc_addr += map->l_addr;
+      break;
+    default:
+      assert (! "unexpected PLT reloc type");
+      break;
+    }
+}
+
+/* The i386 never uses Elf32_Rela relocations.  */
+#define ELF_MACHINE_NO_RELA 1
+
+
+/* Set up the loaded object described by L so its unrelocated PLT
+   entries will jump to the on-demand fixup code in dl-runtime.c.  */
+
+static inline void
+elf_machine_runtime_setup (struct link_map *l)
+{
+  Elf32_Addr *got;
+  extern void _dl_runtime_resolve (Elf32_Word);
+
+  /* The GOT entries for functions in the PLT have not yet been filled
+     in.  Their initial contents will arrange when called to push an
+     offset into the .rel.plt section, push _GLOBAL_OFFSET_TABLE_[1],
+     and then jump to _GLOBAL_OFFSET_TABLE[2].  */
+  got = (Elf32_Addr *) (l->l_addr + l->l_info[DT_PLTGOT]->d_un.d_ptr);
+  got[1] = (Elf32_Addr) l;	/* Identify this shared object.  */
+  /* This function will get called to fix up the GOT entry indicated by
+     the offset on the stack, and then jump to the resolved address.  */
+  got[2] = (Elf32_Addr) &_dl_runtime_resolve;
+}
+
+
+/* Mask identifying addresses reserved for the user program,
+   where the dynamic linker should not map anything.  */
+#define ELF_MACHINE_USER_ADDRESS_MASK	0xf8000000UL
+
+
+
+/* Initial entry point code for the dynamic linker.
+   The C function `_dl_start' is the real entry point;
+   its return value is the user program's entry point.  */
+
+#define RTLD_START asm ("\
+.text\n\
+.globl _start\n\
+.globl _dl_start_user\n\
+_start:\n\
+	call _dl_start\n\
+_dl_start_user:\n\
+	# Save the user entry point address in %edi.\n\
+	movl %eax, %edi\n\
+	# Point %ebx at the GOT.
+	call 0f\n\
+0:	popl %ebx\n\
+	addl $_GLOBAL_OFFSET_TABLE_+[.-0b], %ebx\n\
+	# See if we were run as a command with the executable file\n\
+	# name as an extra leading argument.\n\
+	movl rtld_command@GOT(%ebx), %eax\n\
+	movl (%eax),%eax\n\
+	testl %eax,%eax\n\
+	jz 0f\n\
+	# Pop the original argument count, decrement it, and replace\n\
+	# the original first argument pointer with the new count.\n\
+	popl %eax\n\
+	decl %eax\n\
+	movl %eax,(%esp)\n\
+	# Call _dl_init_next to return the address of an initializer\n\
+	# function to run.\n\
+0:	call _dl_init_next@PLT\n\
+	# Check for zero return, when out of initializers.\n\
+	testl %eax,%eax\n\
+	jz 1f\n\
+	# Call the shared object initializer function.\n\
+	# NOTE: We depend only on the registers (%ebx and %edi)\n\
+	# and the return address pushed by this call;\n\
+	# the initializer is called with the stack just\n\
+	# as it appears on entry, and it is free to move\n\
+	# the stack around, as long as it winds up jumping to\n\
+	# the return address on the top of the stack.\n\
+	call *%eax\n\
+	# Loop to call _dl_init_next for the next initializer.\n\
+	jmp 0b\n\
+1:	# Pass our finalizer function to the user in %edx, as per ELF ABI.\n\
+	movl _dl_fini@GOT(%ebx), %edx\n\
+	# Jump to the user's entry point.\n\
+	jmp *%edi\n\
+");