Mon Oct 9 02:54:14 1995 Roland McGrath <roland@churchy.gnu.ai.mit.edu>

	* Makeconfig (config-LDFLAGS): Define to
	-Wl-dynamic-linker=$(libdir)$(rtld-installed-name).
	(rtld-installed-name): New variable.
	* elf/Makefile (install-lib): Variable removed.
	(install-others): Define this instead, to
	$(libdir)(rtld-installed-name). 
	($(libdir)(rtld-installed-name)): New target; install from ld.so.

	* elf/ldd.sh.in: New file.
	* elf/Makefile (distribute): Add ldd.sh.in.
	(install-bin): Add ldd.
	($(objpfx)ldd: ldd.sh.in): New rule.

	* sysdeps/mach/hurd/dl-sysdep.c: Use __hurd_fail throughout.
	* hurd/hurd.h (__hurd_fail): Replace macro with inline function.
	Translate some Mach errors to Hurd errors.

	* elf/rtld.c (dl_main): Under --list, print msg if executable is
	statically linked.

	* elf/dl-load.c (_dl_map_object_from_fd): Rewrote program header
	table processing.

Sat Oct  7 01:25:48 1995  Roland McGrath  <roland@churchy.gnu.ai.mit.edu>

	* sysdeps/stub/machine-gmon.h: Add #error.

Fri Oct  6 01:49:48 1995  Roland McGrath  <roland@churchy.gnu.ai.mit.edu>

	* elf/dynamic-link.h (elf_get_dynamic_info): If DYN is null, don't
	examine it.

5 files changed, 177 insertions, 111 deletions

diff --git a/elf/Makefile b/elf/Makefile
index 0065d2b..203406d 100644
--- a/elf/Makefile
+++ b/elf/Makefile
@@ -27,18 +27,18 @@ extra-libs	= libelf libdl
 libelf-routines	:= elf_hash
 libdl-routines	:= dlopen dlclose dlsym dlerror
 libdl-inhibit-o	= $(filter-out .so,$(object-suffixes)) # Build only shared.
-LDFLAGS-dl.so	:= -e 0 # work around ld bug
 
 rtld-routines	:= rtld $(addprefix dl-,load lookup object reloc	\
 				        runtime sysdep error init fini)
 distribute	= $(rtld-routines:=.c) dynamic-link.h do-rel.h \
-		  soinit.c sofini.c
+		  soinit.c sofini.c ldd.sh.in
 
 include ../Makeconfig
 
 ifeq (yes,$(build-shared))
 extra-objs	= $(rtld-routines:=.so) soinit.so sofini.so
-install-lib	= ld.so
+install-others	= $(libdir)(rtld-installed-name)
+install-bin	= ldd
 endif
 
 include ../Rules
@@ -54,3 +54,9 @@ $(objpfx)libdl.so: $(objpfx)libdl_pic.a $(common-objpfx)libc.so $(objpfx)ld.so
 	$(LINK.o) -shared -o $(@:$(objpfx)%=%) \
 		  $(LDFLAGS.so) $(LDFLAGS-dl.so) \
 		  -Wl,--whole-archive $(^:$(objpfx)%=%)
+
+$(libdir)$(rtld-installed-name): $(objpfx)ld.so; $(do-install-program)
+
+$(objpfx)ldd: ldd.sh.in
+	sed 's%@RTLD@%$(libdir)/$(rtld-installed-name)%g' < $< > $@.new
+	mv -f $@.new $@
diff --git a/elf/dl-load.c b/elf/dl-load.c
index 12b945a..b70ba55 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -166,6 +166,7 @@ _dl_map_object_from_fd (const char *name, int fd, char *realname)
   void *file_mapping = NULL;
   size_t mapping_size = 0;
 
+#define LOSE(s) lose (0, (s))
   void lose (int code, const char *msg)
     {
       (void) close (fd);
@@ -174,6 +175,17 @@ _dl_map_object_from_fd (const char *name, int fd, char *realname)
       _dl_signal_error (code, l ? l->l_name : name, msg);
     }
 
+  inline caddr_t map_segment (Elf32_Addr mapstart, size_t len,
+			      int prot, int fixed, off_t offset)
+    {
+      caddr_t mapat = mmap ((caddr_t) mapstart, len, prot,
+			    fixed|MAP_COPY|MAP_FILE|MAP_INHERIT,
+			    fd, offset);
+      if (mapat == (caddr_t) -1)
+	lose (errno, "failed to map segment from shared object");
+      return mapat;
+    }
+
   /* Make sure LOCATION is mapped in.  */
   void *map (off_t location, size_t size)
     {
@@ -194,6 +206,9 @@ _dl_map_object_from_fd (const char *name, int fd, char *realname)
     }
 
   const Elf32_Ehdr *header;
+  const Elf32_Phdr *phdr;
+  const Elf32_Phdr *ph;
+  int type;
 
   /* Look again to see if the real name matched another already loaded.  */
   for (l = _dl_loaded; l; l = l->l_next)
@@ -210,8 +225,6 @@ _dl_map_object_from_fd (const char *name, int fd, char *realname)
   /* Map in the first page to read the header.  */
   header = map (0, sizeof *header);
 
-#undef LOSE
-#define LOSE(s) lose (0, (s))
   /* Check the header for basic validity.  */
   if (*(Elf32_Word *) &header->e_ident != ((ELFMAG0 << (EI_MAG0 * 8)) |
 					   (ELFMAG1 << (EI_MAG1 * 8)) |
@@ -242,27 +255,26 @@ _dl_map_object_from_fd (const char *name, int fd, char *realname)
 	_dl_signal_error (errno, NULL, "cannot open zero fill device");
     }
 
-  {
-    /* Copy the program header table into stack space so we can then unmap
-       the headers.  */
-    Elf32_Phdr phdr[header->e_phnum];
-    const Elf32_Phdr *ph;
-    int anywhere, type;
+  /* Extract the remaining details we need from the ELF header
+     and then map in the program header table.  */
+  l->l_entry = header->e_entry;
+  type = header->e_type;
+  l->l_phnum = header->e_phnum;
+  phdr = map (header->e_phoff, l->l_phnum * sizeof (Elf32_Phdr));
 
-    type = header->e_type;
-    anywhere = type == ET_DYN || type == ET_REL;
-    l->l_entry = header->e_entry;
-
-    ph = map (header->e_phoff, header->e_phnum * sizeof (Elf32_Phdr));
-    memcpy (phdr, ph, sizeof phdr);
-    l->l_phnum = header->e_phnum;
-
-    /* We are done reading the file's headers now.  Unmap them.  */
-    munmap (file_mapping, mapping_size);
+  {
+    /* Scan the program header table, collecting its load commands.  */
+    struct loadcmd
+      {
+	Elf32_Addr mapstart, mapend, dataend, allocend;
+	off_t mapoff;
+	int prot;
+      } loadcmds[l->l_phnum], *c;
+    size_t nloadcmds = 0;
 
-    /* Scan the program header table, processing its load commands.  */
-    l->l_addr = 0;
     l->l_ld = 0;
+    l->l_phdr = 0;
+    l->l_addr = 0;
     for (ph = phdr; ph < &phdr[l->l_phnum]; ++ph)
       switch (ph->p_type)
 	{
@@ -277,114 +289,126 @@ _dl_map_object_from_fd (const char *name, int fd, char *realname)
 	  break;
 
 	case PT_LOAD:
-	  /* A load command tells us to map in part of the file.  */
+	  /* A load command tells us to map in part of the file.
+	     We record the load commands and process them all later.  */
 	  if (ph->p_align % pagesize != 0)
 	    LOSE ("ELF load command alignment not page-aligned");
 	  if ((ph->p_vaddr - ph->p_offset) % ph->p_align)
 	    LOSE ("ELF load command address/offset not properly aligned");
 	  {
-	    Elf32_Addr mapstart = ph->p_vaddr & ~(ph->p_align - 1);
-	    Elf32_Addr mapend = ((ph->p_vaddr + ph->p_filesz + ph->p_align - 1)
-				 & ~(ph->p_align - 1));
-	    off_t mapoff = ph->p_offset & ~(ph->p_align - 1);
-	    caddr_t mapat;
-	    int prot = 0;
+	    struct loadcmd *c = &loadcmds[nloadcmds++];
+	    c->mapstart = ph->p_vaddr & ~(ph->p_align - 1);
+	    c->mapend = ((ph->p_vaddr + ph->p_filesz + ph->p_align - 1)
+			 & ~(ph->p_align - 1));
+	    c->dataend = ph->p_vaddr + ph->p_filesz;
+	    c->allocend = ph->p_vaddr + ph->p_memsz;
+	    c->mapoff = ph->p_offset & ~(ph->p_align - 1);
+	    c->prot = 0;
 	    if (ph->p_flags & PF_R)
-	      prot |= PROT_READ;
+	      c->prot |= PROT_READ;
 	    if (ph->p_flags & PF_W)
-	      prot |= PROT_WRITE;
+	      c->prot |= PROT_WRITE;
 	    if (ph->p_flags & PF_X)
-	      prot |= PROT_EXEC;
+	      c->prot |= PROT_EXEC;
+	    break;
+	  }
+	}
 
-	    if (anywhere)
-	      {
-		/* XXX this loses if the first segment mmap call puts
-		   it someplace where the later segments cannot fit.  */
-		mapat = mmap ((caddr_t) (l->l_addr + mapstart),
-			      mapend - mapstart,
-			      prot, MAP_COPY|MAP_FILE|MAP_INHERIT |
-			      /* Let the system choose any convenient
-				 location if this is the first segment.
-				 Following segments must be contiguous in
-				 virtual space with the first.  */
-			      (l->l_addr == 0 ? 0 : MAP_FIXED),
-			      fd, mapoff);
-		if (l->l_addr == 0)
-		  /* This was the first segment mapped, so MAPAT is
-		     the address the system chose for us.  Record it.  */
-		  l->l_addr = (Elf32_Addr) mapat - mapstart;
-	      }
-	    else
-	      {
-		mapat = mmap ((caddr_t) mapstart, mapend - mapstart,
-			      prot, MAP_COPY|MAP_FILE|MAP_INHERIT|MAP_FIXED,
-			      fd, mapoff);
-		/* This file refers to absolute addresses.  So consider its
-		   "load base" to be zero, since that is what we add to the
-		   file's addresses to find them in our memory.  */
-		l->l_addr = 0;
-	      }
-	    if (mapat == (caddr_t) -1)
-	      lose (errno, "failed to map segment from shared object");
+    /* We are done reading the file's headers now.  Unmap them.  */
+    munmap (file_mapping, mapping_size);
+
+    /* Now process the load commands and map segments into memory.  */
+    c = loadcmds;
+
+    if (type == ET_DYN || type == ET_REL)
+      {
+	/* This is a position-independent shared object.  We can let the
+	   kernel map it anywhere it likes, but we must have space for all
+	   the segments in their specified positions relative to the first.
+	   So we map the first segment without MAP_FIXED, but with its
+	   extent increased to cover all the segments.  Then we unmap the
+	   excess portion, and there is known sufficient space there to map
+	   the later segments.  */
+ 	caddr_t mapat;
+	mapat = map_segment (c->mapstart,
+			     loadcmds[nloadcmds - 1].allocend - c->mapstart,
+			     c->prot, 0, c->mapoff);
+	l->l_addr = (Elf32_Addr) mapat - c->mapstart;
+
+	/* Unmap the excess portion, and then jump into the normal
+	   segment-mapping loop to handle the portion of the segment past
+	   the end of the file mapping.  */
+	munmap (mapat + c->mapend,
+		loadcmds[nloadcmds - 1].allocend - c->mapend);
+	goto postmap;
+      }
+
+    while (c < &loadcmds[nloadcmds])
+      {
+	if (c->mapend > c->mapstart)
+	  /* Map the segment contents from the file.  */
+	  map_segment (l->l_addr + c->mapstart, c->mapend - c->mapstart,
+		       c->prot, MAP_FIXED, c->mapoff);
+
+      postmap:
+	if (c->allocend > c->dataend)
+	  {
+	    /* Extra zero pages should appear at the end of this segment,
+	       after the data mapped from the file.   */
+	    Elf32_Addr zero, zeroend, zeropage;
+
+	    zero = l->l_addr + c->dataend;
+	    zeroend = l->l_addr + c->allocend;
+	    zeropage = (zero + pagesize - 1) & ~(pagesize - 1);
 
-	    if (ph->p_memsz > ph->p_filesz)
+	    if (zeroend < zeropage)
+	      /* All the extra data is in the last page of the segment.
+		 We can just zero it.  */
+	      zeropage = zeroend;
+
+	    if (zeropage > zero)
 	      {
-		/* Extra zero pages should appear at the end of this segment,
-		   after the data mapped from the file.   */
-		caddr_t zero, zeroend, zeropage;
-
-		mapat += ph->p_vaddr - mapstart;
-		zero = mapat + ph->p_filesz;
-		zeroend = mapat + ph->p_memsz;
-		zeropage = (caddr_t) ((Elf32_Addr) (zero + pagesize - 1)
-				      & ~(pagesize - 1));
-
-		if (zeroend < zeropage)
-		  /* All the extra data is in the last page of the segment.
-		     We can just zero it.  */
-		  zeropage = zeroend;
-		if (zeropage > zero)
+		/* Zero the final part of the last page of the segment.  */
+		if ((c->prot & PROT_WRITE) == 0)
 		  {
-		    /* Zero the final part of the last page of the segment.  */
-		    if ((prot & PROT_WRITE) == 0)
-		      {
-			/* Dag nab it.  */
-			if (mprotect ((caddr_t) ((Elf32_Addr) zero
-						 & ~(pagesize - 1)),
-				      pagesize,
-				      prot|PROT_WRITE) < 0)
-			  lose (errno, "cannot change memory protections");
-		      }
-		    memset (zero, 0, zeropage - zero);
-		    if ((prot & PROT_WRITE) == 0)
-		      mprotect ((caddr_t) ((Elf32_Addr) zero
-					   & ~(pagesize - 1)),
-				pagesize, prot);
+		    /* Dag nab it.  */
+		    if (mprotect ((caddr_t) (zero & ~(pagesize - 1)),
+				  pagesize, c->prot|PROT_WRITE) < 0)
+		      lose (errno, "cannot change memory protections");
 		  }
+		memset ((void *) zero, 0, zeropage - zero);
+		if ((c->prot & PROT_WRITE) == 0)
+		  mprotect ((caddr_t) (zero & ~(pagesize - 1)),
+			    pagesize, c->prot);
+	      }
 
-		if (zeroend > zeropage)
-		  /* Map the remaining zero pages in from the zero fill FD.  */
-		  mapat = mmap (zeropage, zeroend - zeropage, prot,
-				MAP_ANON|MAP_PRIVATE|MAP_FIXED|MAP_INHERIT,
-				_dl_zerofd, 0);
+	    if (zeroend > zeropage)
+	      {
+		/* Map the remaining zero pages in from the zero fill FD.  */
+		caddr_t mapat;
+		mapat = mmap ((caddr_t) zeropage, zeroend - zeropage, c->prot,
+			      MAP_ANON|MAP_PRIVATE|MAP_FIXED|MAP_INHERIT,
+			      _dl_zerofd, 0);
+		if (mapat == (caddr_t) -1)
+		  lose (errno, "cannot map zero pages");
 	      }
 	  }
-	}
 
-    if (l->l_ld == 0)
-      {
-	if (type == ET_DYN)
-	  LOSE ("object file has no dynamic section");
+	++c;
       }
-    else
-      (Elf32_Addr) l->l_ld += l->l_addr;
+  }
 
-    if (l->l_phdr == 0)
-      l->l_phdr = (void *) ((const Elf32_Ehdr *) l->l_addr)->e_phoff;
-    (Elf32_Addr) l->l_phdr += l->l_addr;
+  if (l->l_ld == 0)
+    {
+      if (type == ET_DYN)
+	LOSE ("object file has no dynamic section");
+    }
+  else
+    (Elf32_Addr) l->l_ld += l->l_addr;
 
-    l->l_entry += l->l_addr;
-  }
+  if (l->l_phdr == 0)
+    l->l_phdr = (void *) ((const Elf32_Ehdr *) l->l_addr)->e_phoff;
+  (Elf32_Addr) l->l_phdr += l->l_addr;
 
   elf_get_dynamic_info (l->l_ld, l->l_info);
   if (l->l_info[DT_HASH])
diff --git a/elf/dynamic-link.h b/elf/dynamic-link.h
index a7316ee..84d440e 100644
--- a/elf/dynamic-link.h
+++ b/elf/dynamic-link.h
@@ -32,6 +32,9 @@ elf_get_dynamic_info (Elf32_Dyn *dyn, Elf32_Dyn *info[DT_NUM])
   for (i = 0; i < DT_NUM; ++i)
     info[i] = NULL;
 
+  if (! dyn)
+    return;
+
   while (dyn->d_tag != DT_NULL)
     {
       assert (dyn->d_tag < DT_NUM);
diff --git a/elf/ldd.sh.in b/elf/ldd.sh.in
new file mode 100644
index 0000000..58ae501
--- /dev/null
+++ b/elf/ldd.sh.in
@@ -0,0 +1,26 @@
+#! /bin/sh
+
+# This is the `ldd' command, which lists what shared libraries are
+# used by given dynamically-linked executables.  It works by invoking the
+# run-time dynamic linker as a command and giving it the special `--list'
+# switch.
+
+RTLD=@RTLD@
+
+case $# in
+0)
+  echo >&2 "Usage: $0 FILE..."
+  exit 1 ;;
+1)
+  # We don't list the file name when there is only one.
+  exec ${RTLD} --list "$1" && exit 1
+  exit ;;
+*)
+  set -e	# Bail out immediately if ${RTLD} loses on any argument.
+  for file; do
+    echo "${file}:"
+    ${RTLD} --list "$file"
+  done
+esac
+
+exit 0
diff --git a/elf/rtld.c b/elf/rtld.c
index 6be05eb..d780fcb 100644
--- a/elf/rtld.c
+++ b/elf/rtld.c
@@ -281,6 +281,13 @@ of this helper program; chances are you did not intend to run this program.\n",
 
       if (list_only)
 	{
+	  if (! _dl_loaded->l_info[DT_NEEDED])
+	    {
+	      _dl_sysdep_message (_dl_loaded->l_name, ": statically linked\n",
+				  NULL);
+	      _exit (1);
+	    }
+
 	  for (l = _dl_loaded->l_next; l; l = l->l_next)
 	    {
 	      char buf[20], *bp;