[src/trunk]: src/libexec/ld.elf_so switch back to using a file mapping for th...

[chs <chs%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e5d7182f5407
branches:  trunk
changeset: 482069:e5d7182f5407
user:      chs <chs%NetBSD.org@localhost>
date:      Sun Feb 13 04:28:09 2000 +0000

description:
switch back to using a file mapping for the initial mapping of a new object.
this allows the kernel to use PMAP_PREFER() to give us better alignment on
platforms that care.

diffstat:

 libexec/ld.elf_so/map_object.c |  54 ++++++++++++++++++++++-------------------
 1 files changed, 29 insertions(+), 25 deletions(-)

diffs (102 lines):

diff -r c2f2547efa8d -r e5d7182f5407 libexec/ld.elf_so/map_object.c
--- a/libexec/ld.elf_so/map_object.c    Sun Feb 13 03:34:40 2000 +0000
+++ b/libexec/ld.elf_so/map_object.c    Sun Feb 13 04:28:09 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: map_object.c,v 1.10 1999/11/07 00:21:13 mycroft Exp $   */
+/*     $NetBSD: map_object.c,v 1.11 2000/02/13 04:28:09 chs Exp $       */
 
 /*
  * Copyright 1996 John D. Polstra.
@@ -178,57 +178,60 @@
 #endif
 
        /*
-        * Map the entire address space of the object as an anonymous
+        * Map the entire address space of the object as a file
         * region to stake out our contiguous region and establish a
-        * base for relocation.
+        * base for relocation.  We use a file mapping so that
+        * the kernel will give us whatever alignment is appropriate
+        * for the platform we're running on.
         *
-        * We map it using the data/BSS protection, then overlay bits
-        * of the file over the top, and unmap the gaps left by padding
-        * to alignment.
+        * We map it using the text protection, map the data segment
+        * into the right place, then map an anon segment for the bss
+        * and unmap the gaps left by padding to alignment.
         */
+
        base_offset = round_down(segs[0]->p_offset);
        base_vaddr = round_down(segs[0]->p_vaddr);
        base_vlimit = round_up(segs[1]->p_vaddr + segs[1]->p_memsz);
+       text_vlimit = round_up(segs[0]->p_vaddr + segs[0]->p_memsz);
        mapsize = base_vlimit - base_vaddr;
+
 #ifdef RTLD_LOADER
        base_addr = u.hdr.e_type == ET_EXEC ? (caddr_t) base_vaddr : NULL;
 #else
        base_addr = NULL;
 #endif
 
-       mapbase = mmap(base_addr, mapsize, protflags(segs[1]->p_flags),
-                      MAP_ANON | MAP_PRIVATE, -1, (off_t) 0);
+       mapbase = mmap(base_addr, mapsize, protflags(segs[0]->p_flags),
+                      MAP_FILE | MAP_PRIVATE, fd, base_offset);
        if (mapbase == MAP_FAILED) {
                _rtld_error("mmap of entire address space failed: %s",
                    xstrerror(errno));
                return NULL;
        }
-       if (base_addr != NULL && mapbase != base_addr) {
-               _rtld_error("mmap returned wrong address: wanted %p, got %p",
-                   base_addr, mapbase);
-               munmap(mapbase, mapsize);
-               return NULL;
-       }
+
        base_addr = mapbase;
 
-       /* Overlay the text segment onto the proper region. */
-       text_vlimit = round_up(segs[0]->p_vaddr + segs[0]->p_memsz);
-       if (mmap(base_addr, text_vlimit - base_vaddr,
-           protflags(segs[0]->p_flags), MAP_FILE | MAP_PRIVATE | MAP_FIXED,
-           fd, base_offset) == MAP_FAILED) {
-               _rtld_error("mmap of text failed: %s", xstrerror(errno));
-               return NULL;
-       }
-
        /* Overlay the data segment onto the proper region. */
        data_offset = round_down(segs[1]->p_offset);
        data_vaddr = round_down(segs[1]->p_vaddr);
        data_vlimit = round_up(segs[1]->p_vaddr + segs[1]->p_filesz);
        data_addr = mapbase + (data_vaddr - base_vaddr);
        if (mmap(data_addr, data_vlimit - data_vaddr,
-           protflags(segs[1]->p_flags), MAP_FILE | MAP_PRIVATE | MAP_FIXED,
-           fd, data_offset) == MAP_FAILED) {
+                protflags(segs[1]->p_flags),
+                MAP_FILE | MAP_PRIVATE | MAP_FIXED, fd, data_offset)
+           == MAP_FAILED) {
                _rtld_error("mmap of data failed: %s", xstrerror(errno));
+               munmap(mapbase, mapsize);
+               return NULL;
+       }
+
+       /* Overlay the bss segment onto the proper region. */
+       if (mmap(mapbase + data_vlimit - base_vaddr, base_vlimit - data_vlimit,
+                protflags(segs[1]->p_flags),
+                MAP_ANON | MAP_PRIVATE | MAP_FIXED, -1, 0)
+           == MAP_FAILED) {
+               _rtld_error("mmap of bss failed: %s", xstrerror(errno));
+               munmap(mapbase, mapsize);
                return NULL;
        }
 
@@ -238,6 +241,7 @@
        if (gap_size != 0 && munmap(gap_addr, gap_size) == -1) {
                _rtld_error("munmap of text -> data gap failed: %s",
                    xstrerror(errno));
+               munmap(mapbase, mapsize);
                return NULL;
        }