[PATCH 07/12] elf: convert _dl_map_segments's mmap() to a callback

[Stas Sergeev <stsp2@yandex.ru>]

This only applies to file-based mmap.
Since _dl_map_segment() was converted to
anonymous mmap, only 1 place is now converted
to a callback.

The test-suite was run on x86_64/64 and showed no regressions.

Signed-off-by: Stas Sergeev <stsp2@yandex.ru>
---
 elf/dl-load.c         | 19 ++++++++++++++-----
 elf/dl-load.h         |  8 ++++++--
 elf/dl-map-segments.h |  6 +++---
 3 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/elf/dl-load.c b/elf/dl-load.c
index ceafaa4228..c0704dc89c 100644
--- a/elf/dl-load.c
+++ b/elf/dl-load.c
@@ -975,11 +975,12 @@ _dl_process_phdrs (struct link_map *l, int fd)
 }
 
 static int
-_dl_map_object_1 (struct link_map *l, int fd,
+_dl_map_object_1 (struct link_map *l, void *fd,
                   struct filebuf *fbp,
                   int mode, struct link_map *loader,
                   void **stack_endp, int *errval_p,
-                  const char **errstring_p)
+                  const char **errstring_p,
+                  __typeof (do_mmap) *m_map)
 {
   const ElfW(Ehdr) *header;
   const ElfW(Phdr) *phdr;
@@ -1179,7 +1180,7 @@ _dl_map_object_1 (struct link_map *l, int fd,
        l_map_start, l_map_end, l_addr, l_contiguous, l_text_end, l_phdr
      */
     errstring = _dl_map_segments (l, fd, header, type, loadcmds, nloadcmds,
-				  maplength, has_holes, loader);
+				  maplength, has_holes, loader, m_map);
     if (__glibc_unlikely (errstring != NULL))
       {
 	/* Mappings can be in an inconsistent state: avoid unmap.  */
@@ -1430,6 +1431,14 @@ _dl_map_object_2 (struct link_map *l, int mode,
 /* Map in the shared object NAME, actually located in REALNAME, and already
    opened on FD.  */
 
+static void *
+do_mmap (void *addr, size_t length, int prot, int flags,
+         void *arg, off_t offset)
+{
+  int fd = arg ? *(const int *) arg : -1;
+  return __mmap (addr, length, prot, flags, fd, offset);
+}
+
 #ifndef EXTERNAL_MAP_FROM_FD
 static
 #endif
@@ -1550,8 +1559,8 @@ _dl_map_object_from_fd (const char *name, const char *origname, int fd,
       goto lose_errno;
     }
 
-  if (_dl_map_object_1 (l, fd, fbp, mode, loader, stack_endp, &errval,
-                        &errstring))
+  if (_dl_map_object_1 (l, &fd, fbp, mode, loader, stack_endp, &errval,
+                        &errstring, do_mmap))
     goto lose;
 
   _dl_process_phdrs (l, fd);
diff --git a/elf/dl-load.h b/elf/dl-load.h
index ecf6910c68..eff5146acd 100644
--- a/elf/dl-load.h
+++ b/elf/dl-load.h
@@ -80,6 +80,9 @@ struct loadcmd
   int prot;                             /* PROT_* bits.  */
 };
 
+static void *
+do_mmap (void *addr, size_t length, int prot, int flags,
+         void *arg, off_t offset);
 
 /* This is a subroutine of _dl_map_segments.  It should be called for each
    load command, some time after L->l_addr has been set correctly.  It is
@@ -113,13 +116,14 @@ _dl_postprocess_loadcmd (struct link_map *l, const ElfW(Ehdr) *header,
    The file <dl-map-segments.h> defines this function.  The canonical
    implementation in elf/dl-map-segments.h might be replaced by a sysdeps
    version.  */
-static const char *_dl_map_segments (struct link_map *l, int fd,
+static const char *_dl_map_segments (struct link_map *l, void *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);
+                                     struct link_map *loader,
+                                     __typeof (do_mmap) *m_map);
 
 /* All the error message strings _dl_map_segments might return are
    listed here so that different implementations in different sysdeps
diff --git a/elf/dl-map-segments.h b/elf/dl-map-segments.h
index ed7675cabf..7bcfcd9eff 100644
--- a/elf/dl-map-segments.h
+++ b/elf/dl-map-segments.h
@@ -74,11 +74,11 @@ _dl_map_segment (ElfW(Addr) mappref, size_t maplength, size_t mapalign)
    other use of those parts of the address space).  */
 
 static __always_inline const char *
-_dl_map_segments (struct link_map *l, int fd,
+_dl_map_segments (struct link_map *l, void *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)
+                  struct link_map *loader, __typeof (do_mmap) *m_map)
 {
   const struct loadcmd *c = loadcmds;
 
@@ -138,7 +138,7 @@ _dl_map_segments (struct link_map *l, int fd,
     {
       if (c->mapend > c->mapstart
           /* Map the segment contents from the file.  */
-          && (__mmap ((void *) (l->l_addr + c->mapstart),
+          && (m_map ((void *) (l->l_addr + c->mapstart),
                       c->mapend - c->mapstart, c->prot,
                       MAP_FIXED|MAP_COPY|MAP_FILE,
                       fd, c->mapoff)
-- 
2.37.2