Split vDSO range lookup to a gdbarch hook

We have a case in solib-svr4.c where we could reuse symfile-mem.c's
vDSO range lookup.  Since symfile-mem.c is not present in all
configurations solib-svr4.c is, move that lookup to a gdbarch hook.

This has the minor (good) side effect that we stop even trying the
target_auxv_search lookup against targets that don't have a concept of
a vDSO, in case symfile-mem.c happens to be linked in the build
(--enable-targets=all).

Tested on x86_64 Fedora 20.

gdb/
2014-10-10  Pedro Alves  <palves@redhat.com>

	* arch-utils.c (default_vsyscall_range): New function.
	* arch-utils.h (default_vsyscall_range): New declaration.
	* gdbarch.sh (vsyscall_range): New hook.
	* gdbarch.h, gdbarch.c: Regenerate.
	* linux-tdep.c (linux_vsyscall_range): New function.
	(linux_init_abi): Install linux_vsyscall_range as
	vsyscall_range gdbarch hook.
	* memrange.c (address_in_mem_range): New function.
	* memrange.h (address_in_mem_range): New declaration.
	* symfile-mem.c (find_vdso_size): Delete function.
	(add_vsyscall_page): Use gdbarch_vsyscall_range.

1 files changed, 5 insertions, 26 deletions

diff --git a/gdb/symfile-mem.c b/gdb/symfile-mem.c
index b6986b0ec72..eea97fd88b4 100644
--- a/gdb/symfile-mem.c
+++ b/gdb/symfile-mem.c
@@ -187,33 +187,15 @@ symbol_file_add_from_memory_wrapper (struct ui_out *uiout, void *data)
   return 0;
 }
 
-/* Rummage through mappings to find the vsyscall page size.  */
-
-static int
-find_vdso_size (CORE_ADDR vaddr, unsigned long size,
-		int read, int write, int exec, int modified,
-		void *data)
-{
-  struct symbol_file_add_from_memory_args *args = data;
-
-  if (vaddr == args->sysinfo_ehdr)
-    {
-      args->size = size;
-      return 1;
-    }
-  return 0;
-}
-
 /* Try to add the symbols for the vsyscall page, if there is one.
    This function is called via the inferior_created observer.  */
 
 static void
 add_vsyscall_page (struct target_ops *target, int from_tty)
 {
-  CORE_ADDR sysinfo_ehdr;
+  struct mem_range vsyscall_range;
 
-  if (target_auxv_search (target, AT_SYSINFO_EHDR, &sysinfo_ehdr) > 0
-      && sysinfo_ehdr != (CORE_ADDR) 0)
+  if (gdbarch_vsyscall_range (target_gdbarch (), &vsyscall_range))
     {
       struct bfd *bfd;
       struct symbol_file_add_from_memory_args args;
@@ -236,14 +218,11 @@ add_vsyscall_page (struct target_ops *target, int from_tty)
 	  return;
 	}
       args.bfd = bfd;
-      args.sysinfo_ehdr = sysinfo_ehdr;
-      args.size = 0;
-      if (gdbarch_find_memory_regions_p (target_gdbarch ()))
-	(void) gdbarch_find_memory_regions (target_gdbarch (),
-					    find_vdso_size, &args);
+      args.sysinfo_ehdr = vsyscall_range.start;
+      args.size = vsyscall_range.length;
 
       args.name = xstrprintf ("system-supplied DSO at %s",
-			      paddress (target_gdbarch (), sysinfo_ehdr));
+			      paddress (target_gdbarch (), vsyscall_range.start));
       /* Pass zero for FROM_TTY, because the action of loading the
 	 vsyscall DSO was not triggered by the user, even if the user
 	 typed "run" at the TTY.  */