Use ALIGN_* macros in _dl_map_object_from_fd.

Cleanup _dl_map_object_from_fd to make it clear exactly
what we're doing with the mappings i.e. extending the the
start of the map down to a page boundary, extending the
end of the map up to a page boundary, and offset itself
also to page boundary. The result is much easier to read
as expected from the ALIGN_* cleanups.

diff --git a/ChangeLog b/ChangeLog
index 760e9bc..bb75382 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2015-09-18  Carlos O'Donell  <carlos@redhat.com>
+
+       * elf/dl-load.c: Include libc-internal.h.
+       (_dl_map_object_from_fd): Use ALIGN_UP and ALIGN_DOWN.
+
 2015-09-18  Vincent Bernat  <vincent@bernat.im>
 
        [BZ #17887]

diff --git a/elf/dl-load.c b/elf/dl-load.c
index 0c052e4..993a419 100644 (file)
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -36,6 +36,7 @@
 #include <caller.h>
 #include <sysdep.h>
 #include <stap-probe.h>
+#include <libc-internal.h>
 
 #include <dl-dst.h>
 #include <dl-load.h>
@@ -1077,12 +1078,11 @@ _dl_map_object_from_fd (const char *name, int fd, struct filebuf *fbp,
            }
 
          struct loadcmd *c = &loadcmds[nloadcmds++];
-         c->mapstart = ph->p_vaddr & ~(GLRO(dl_pagesize) - 1);
-         c->mapend = ((ph->p_vaddr + ph->p_filesz + GLRO(dl_pagesize) - 1)
-                      & ~(GLRO(dl_pagesize) - 1));
+         c->mapstart = ALIGN_DOWN (ph->p_vaddr, GLRO(dl_pagesize));
+         c->mapend = ALIGN_UP (ph->p_vaddr + ph->p_filesz, GLRO(dl_pagesize));
          c->dataend = ph->p_vaddr + ph->p_filesz;
          c->allocend = ph->p_vaddr + ph->p_memsz;
-         c->mapoff = ph->p_offset & ~(GLRO(dl_pagesize) - 1);
+         c->mapoff = ALIGN_DOWN (ph->p_offset, GLRO(dl_pagesize));
 
          /* Determine whether there is a gap between the last segment
             and this one.  */