Add arm-nacl port.

1 files changed, 238 insertions, 0 deletions

diff --git a/sysdeps/nacl/dl-map-segments.h b/sysdeps/nacl/dl-map-segments.h
new file mode 100644
index 0000000000..f305da304a
--- /dev/null
+++ b/sysdeps/nacl/dl-map-segments.h
@@ -0,0 +1,238 @@
+/* Map in a shared object's segments.  NaCl version.
+   Copyright (C) 2015 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 <assert.h>
+#include <dl-load.h>
+#include <errno.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <libc-internal.h>
+
+
+/* This is basically pread, but with iteration after short reads.  */
+static bool
+read_in_data (int fd, void *data, size_t len, off_t pos)
+{
+  if (__glibc_unlikely (__lseek (fd, pos, SEEK_SET) == (off_t) -1))
+    return true;
+  while (len > 0)
+    {
+      ssize_t n = __read (fd, data, len);
+      if (__glibc_unlikely (n < 0))
+	return true;
+      if (__glibc_unlikely (n == 0))
+	{
+	  errno = EFTYPE;
+	  return true;
+	}
+      data += n;
+      len -= n;
+    }
+  return false;
+}
+
+static const char *
+_dl_map_segments (struct link_map *l, int fd,
+		  const ElfW(Ehdr) *header, int type,
+		  const struct loadcmd loadcmds[], size_t nloadcmds,
+		  const size_t maplength, bool has_holes,
+		  struct link_map *loader)
+{
+  if (__builtin_expect (type, ET_DYN) == ET_DYN)
+    {
+      /* This is a position-independent shared object.  Let the system
+	 choose where to place it.
+
+	 As a refinement, sometimes we have an address that we would
+	 prefer to map such objects at; but this is only a preference,
+	 the OS can do whatever it likes. */
+      ElfW(Addr) mappref
+	= (ELF_PREFERRED_ADDRESS (loader, maplength,
+				  loadcmds[0].mapstart & GLRO(dl_use_load_bias))
+	   - MAP_BASE_ADDR (l));
+
+      uintptr_t mapstart;
+      if (__glibc_likely (loadcmds[0].prot & PROT_EXEC))
+	{
+	  /* When there is a code segment, we must use the
+	     allocate_code_data interface to choose a location.  */
+
+	  uintptr_t code_size = loadcmds[0].allocend - loadcmds[0].mapstart;
+	  uintptr_t data_offset;
+	  size_t data_size;
+
+	  if (__glibc_likely (nloadcmds > 1))
+	    {
+	      data_offset = loadcmds[1].mapstart - loadcmds[0].mapstart;
+	      data_size = ALIGN_UP (maplength - data_offset,
+				    GLRO(dl_pagesize));
+	    }
+	  else
+	    {
+	      data_offset = 0;
+	      data_size = 0;
+	    }
+
+	  int error = __nacl_irt_code_data_alloc.allocate_code_data
+	    (mappref, code_size, data_offset, data_size, &mapstart);
+	  if (__glibc_unlikely (error))
+	    {
+	      errno = error;
+	      return DL_MAP_SEGMENTS_ERROR_MAP_SEGMENT;
+	    }
+	}
+      else
+	{
+	  /* With no code pages involved, plain mmap works fine.  */
+	  void *mapped = __mmap ((void *) mappref, maplength,
+				 PROT_NONE, MAP_ANON, -1, 0);
+	  if (__glibc_unlikely (mapped == MAP_FAILED))
+	    return DL_MAP_SEGMENTS_ERROR_MAP_SEGMENT;
+	  mapstart = (uintptr_t) mapped;
+	}
+
+      l->l_addr = mapstart - loadcmds[0].mapstart;
+    }
+
+  /* Remember which part of the address space this object uses.  */
+  l->l_map_start = loadcmds[0].mapstart + l->l_addr;
+  l->l_map_end = l->l_map_start + maplength;
+  l->l_contiguous = !has_holes;
+
+  /* Now actually map (or read) in each segment.  */
+  for (const struct loadcmd *c = loadcmds; c < &loadcmds[nloadcmds]; ++c)
+    if (__glibc_likely (c->mapend > c->mapstart))
+      {
+	/* Unlike POSIX mmap, NaCl's mmap does not reliably handle COW
+	   faults in the remainder of the final partial page.  So to get
+	   the expected behavior for the unaligned boundary between data
+	   and bss, it's necessary to allocate the final partial page of
+	   data as anonymous memory rather than mapping it from the file.  */
+
+	size_t maplen = c->mapend - c->mapstart;
+	if (c->mapend > c->dataend && c->allocend > c->dataend)
+	  maplen = (c->dataend & -GLRO(dl_pagesize)) - c->mapstart;
+
+	/* Map the segment contents from the file.  */
+	if (__glibc_unlikely (__mmap ((void *) (l->l_addr + c->mapstart),
+				      maplen, c->prot,
+				      MAP_FIXED|MAP_COPY|MAP_FILE,
+				      fd, c->mapoff)
+			      == MAP_FAILED))
+	  {
+	    switch (errno)
+	      {
+	      case EINVAL:
+	      case ENOTSUP:
+	      case ENOSYS:
+		break;
+	      default:
+		return DL_MAP_SEGMENTS_ERROR_MAP_SEGMENT;
+	      }
+
+	    /* No mmap support for this file.  */
+	    if (c->prot & PROT_EXEC)
+	      {
+		/* Read the data into a temporary buffer.  */
+		const size_t len = c->mapend - c->mapstart;
+		void *data = __mmap (NULL, len, PROT_READ | PROT_WRITE,
+				     MAP_ANON|MAP_PRIVATE, -1, 0);
+		if (__glibc_unlikely (data == MAP_FAILED))
+		  return DL_MAP_SEGMENTS_ERROR_MAP_ZERO_FILL;
+		if (read_in_data (fd, data, len, c->mapoff))
+		  return DL_MAP_SEGMENTS_ERROR_MAP_SEGMENT;
+		/* Now validate and install the code.  */
+		int error = __nacl_irt_dyncode.dyncode_create
+		  ((void *) (l->l_addr + c->mapstart), data, len);
+		__munmap (data, len);
+		if (__glibc_unlikely (error))
+		  {
+		    errno = error;
+		    return DL_MAP_SEGMENTS_ERROR_MAP_SEGMENT;
+		  }
+	      }
+	    else
+	      {
+		/* Allocate the pages.  */
+		if (__mmap ((void *) (l->l_addr + c->mapstart),
+			    c->mapend - c->mapstart, c->prot | PROT_WRITE,
+			    MAP_FIXED|MAP_ANON|MAP_PRIVATE, -1, 0)
+		    == MAP_FAILED)
+		  return DL_MAP_SEGMENTS_ERROR_MAP_ZERO_FILL;
+		/* Now read in the data.  */
+		if (read_in_data (fd, (void *) (l->l_addr + c->mapstart),
+				  c->dataend - c->mapstart, c->mapoff))
+		  return DL_MAP_SEGMENTS_ERROR_MAP_SEGMENT;
+		/* Now that we've filled the pages, reset the page
+		   protections to what they should be.  */
+		if (!(c->prot & PROT_WRITE)
+		    && __mprotect ((void *) (l->l_addr + c->mapstart),
+				   c->mapend - c->mapstart, c->prot) < 0)
+		  return DL_MAP_SEGMENTS_ERROR_MPROTECT;
+	      }
+	  }
+	else if (c->allocend > c->dataend)
+	  {
+	    /* Extra zero pages should appear at the end of this segment,
+	       after the data mapped from the file.   */
+
+	    uintptr_t allocend = c->mapend;
+	    if (c->mapend > c->dataend)
+	      {
+		/* The final data page was partial.  So we didn't map it in.
+		   Instead, we must allocate an anonymous page to fill.  */
+		if (c->prot & PROT_WRITE)
+		  /* Do the whole allocation right here.  */
+		  allocend = c->allocend;
+		if (__mmap ((void *) (l->l_addr + c->mapstart + maplen),
+			    allocend - (c->mapstart + maplen), c->prot,
+			    MAP_FIXED|MAP_ANON|MAP_PRIVATE, -1, 0)
+		    == MAP_FAILED)
+		  return DL_MAP_SEGMENTS_ERROR_MAP_ZERO_FILL;
+		if (read_in_data (fd,
+				  (void *) (l->l_addr + c->mapstart + maplen),
+				  c->dataend & (GLRO(dl_pagesize) - 1),
+				  c->mapoff + maplen))
+		  return DL_MAP_SEGMENTS_ERROR_MAP_SEGMENT;
+		/* Now that we've filled the page, reset its
+		   protections to what they should be.  */
+		if (!(c->prot & PROT_WRITE)
+		    && __mprotect ((void *) (l->l_addr + c->mapstart + maplen),
+				   c->mapend - (c->mapstart + maplen),
+				   c->prot) < 0)
+		  return DL_MAP_SEGMENTS_ERROR_MPROTECT;
+	      }
+
+	    /* Now allocate the pure zero-fill pages.  */
+	    if (allocend < c->allocend
+		&& (__mmap ((void *) (l->l_addr + c->mapstart + allocend),
+			   c->allocend - (c->mapstart + allocend), c->prot,
+			   MAP_FIXED|MAP_ANON|MAP_PRIVATE, -1, 0)
+		    == MAP_FAILED))
+	      return DL_MAP_SEGMENTS_ERROR_MAP_ZERO_FILL;
+	  }
+
+	_dl_postprocess_loadcmd (l, header, c);
+      }
+
+  /* Notify ELF_PREFERRED_ADDRESS that we have to load this one
+     fixed.  */
+  ELF_FIXED_ADDRESS (loader, c->mapstart);
+
+  return NULL;
+}