[2/3] gdb: include a still-mapped flag in solib unload notification

diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c
index e7fdeca91ff..6457285caeb 100644
--- a/gdb/breakpoint.c
+++ b/gdb/breakpoint.c
@@ -8090,11 +8090,18 @@  disable_breakpoints_in_shlibs (program_space *pspace)
 
 /* Disable any breakpoints and tracepoints that are in SOLIB upon
    notification of unloaded_shlib.  Only apply to enabled breakpoints,
-   disabled ones can just stay disabled.  */
+   disabled ones can just stay disabled.
+
+   When STILL_IN_USE is true, SOLIB hasn't really been unmapped from
+   the inferior.  In this case, don't disable anything.  */
 
 static void
-disable_breakpoints_in_unloaded_shlib (program_space *pspace, const solib &solib)
+disable_breakpoints_in_unloaded_shlib (program_space *pspace, const solib &solib,
+				       bool still_in_use)
 {
+  if (still_in_use)
+    return;
+
   bool disabled_shlib_breaks = false;
 
   for (bp_location *loc : all_bp_locations ())
diff --git a/gdb/bsd-uthread.c b/gdb/bsd-uthread.c
index eb1ed421abc..67db0ca4bda 100644
--- a/gdb/bsd-uthread.c
+++ b/gdb/bsd-uthread.c
@@ -294,9 +294,10 @@  bsd_uthread_solib_loaded (solib &so)
 }
 
 static void
-bsd_uthread_solib_unloaded (program_space *pspace, const solib &so)
+bsd_uthread_solib_unloaded (program_space *pspace, const solib &so,
+			    bool still_in_use)
 {
-  if (bsd_uthread_solib_name.empty ())
+  if (bsd_uthread_solib_name.empty () || still_in_use)
     return;
 
   if (so.so_original_name == bsd_uthread_solib_name)
diff --git a/gdb/interps.c b/gdb/interps.c
index bd65d1a5cc6..8b8b5782966 100644
--- a/gdb/interps.c
+++ b/gdb/interps.c
@@ -496,9 +496,9 @@  interps_notify_solib_loaded (const solib &so)
 /* See interps.h.  */
 
 void
-interps_notify_solib_unloaded (const solib &so)
+interps_notify_solib_unloaded (const solib &so, bool still_in_use)
 {
-  interps_notify (&interp::on_solib_unloaded, so);
+  interps_notify (&interp::on_solib_unloaded, so, still_in_use);
 }
 
 /* See interps.h.  */
diff --git a/gdb/interps.h b/gdb/interps.h
index 987465c894b..2dcf244dbd7 100644
--- a/gdb/interps.h
+++ b/gdb/interps.h
@@ -153,8 +153,11 @@  class interp : public intrusive_list_node<interp>
   /* Notify the interpreter that solib SO has been loaded.  */
   virtual void on_solib_loaded (const solib &so) {}
 
-  /* Notify the interpreter that solib SO has been unloaded.  */
-  virtual void on_solib_unloaded (const solib &so) {}
+  /* Notify the interpreter that solib SO has been unloaded.  When
+     STILL_IN_USE is true, the objfile backing SO is still in use,
+     this indicates that SO was loaded multiple times, but only mapped
+     in once (the mapping was reused).  */
+  virtual void on_solib_unloaded (const solib &so, bool still_in_use) {}
 
   /* Notify the interpreter that a command it is executing is about to cause
      the inferior to proceed.  */
@@ -332,8 +335,11 @@  extern void interps_notify_target_resumed (ptid_t ptid);
 /* Notify all interpreters that solib SO has been loaded.  */
 extern void interps_notify_solib_loaded (const solib &so);
 
-/* Notify all interpreters that solib SO has been unloaded.  */
-extern void interps_notify_solib_unloaded (const solib &so);
+/* Notify all interpreters that solib SO has been unloaded.  When
+   STILL_IN_USE is true, the objfile backing SO is still in use, this
+   indicates that SO was loaded multiple times, but only mapped in
+   once (the mapping was reused).  */
+extern void interps_notify_solib_unloaded (const solib &so, bool still_in_use);
 
 /* Notify all interpreters that the selected traceframe changed.
 
diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
index ff4a0ff3202..9512706d02f 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -760,7 +760,7 @@  mi_interp::on_solib_loaded (const solib &solib)
 }
 
 void
-mi_interp::on_solib_unloaded (const solib &solib)
+mi_interp::on_solib_unloaded (const solib &solib, bool still_in_use)
 {
   ui_out *uiout = this->interp_ui_out ();
 
diff --git a/gdb/mi/mi-interp.h b/gdb/mi/mi-interp.h
index 8f5eee6f558..beff1c1a98c 100644
--- a/gdb/mi/mi-interp.h
+++ b/gdb/mi/mi-interp.h
@@ -61,7 +61,7 @@  class mi_interp final : public interp
 			  const char *format) override;
   void on_target_resumed (ptid_t ptid) override;
   void on_solib_loaded (const solib &so) override;
-  void on_solib_unloaded (const solib &so) override;
+  void on_solib_unloaded (const solib &so, bool still_in_use) override;
   void on_about_to_proceed () override;
   void on_traceframe_changed (int tfnum, int tpnum) override;
   void on_tsv_created (const trace_state_variable *tsv) override;
diff --git a/gdb/observable.h b/gdb/observable.h
index 077014c8401..deea1ffe7ff 100644
--- a/gdb/observable.h
+++ b/gdb/observable.h
@@ -104,7 +104,8 @@  extern observable<solib &/* solib */> solib_loaded;
 /* The shared library SOLIB has been unloaded from program space PSPACE.
    Note  when gdb calls this observer, the library's symbols have not
    been unloaded yet, and thus are still available.  */
-extern observable<program_space *, const solib &/* solib */> solib_unloaded;
+extern observable<program_space *, const solib &/* solib */,
+		  bool /* still_in_use */> solib_unloaded;
 
 /* The symbol file specified by OBJFILE has been loaded.  */
 extern observable<struct objfile */* objfile */> new_objfile;
diff --git a/gdb/solib.c b/gdb/solib.c
index 4a04f1ddb1f..eee02ca5d24 100644
--- a/gdb/solib.c
+++ b/gdb/solib.c
@@ -691,13 +691,17 @@  notify_solib_loaded (solib &so)
   gdb::observers::solib_loaded.notify (so);
 }
 
-/* Notify interpreters and observers that solib SO has been unloaded.  */
+/* Notify interpreters and observers that solib SO has been unloaded.
+   When STILL_IN_USE is true, the objfile backing SO is still in use,
+   this indicates that SO was loaded multiple times, but only mapped
+   in once (the mapping was reused).  */
 
 static void
-notify_solib_unloaded (program_space *pspace, const solib &so)
+notify_solib_unloaded (program_space *pspace, const solib &so,
+		       bool still_in_use)
 {
-  interps_notify_solib_unloaded (so);
-  gdb::observers::solib_unloaded.notify (pspace, so);
+  interps_notify_solib_unloaded (so, still_in_use);
+  gdb::observers::solib_unloaded.notify (pspace, so, still_in_use);
 }
 
 /* See solib.h.  */
@@ -792,18 +796,23 @@  update_solib_list (int from_tty)
       /* If it's not on the inferior's list, remove it from GDB's tables.  */
       else
 	{
+	  bool still_in_use
+	    = (gdb_iter->objfile != nullptr
+	       && solib_used (current_program_space, *gdb_iter));
+
 	  /* Notify any observer that the shared object has been
 	     unloaded before we remove it from GDB's tables.  */
-	  notify_solib_unloaded (current_program_space, *gdb_iter);
-
-	  current_program_space->deleted_solibs.push_back (gdb_iter->so_name);
+	  notify_solib_unloaded (current_program_space, *gdb_iter,
+				 still_in_use);
 
 	  /* Unless the user loaded it explicitly, free SO's objfile.  */
 	  if (gdb_iter->objfile != nullptr
 	      && !(gdb_iter->objfile->flags & OBJF_USERLOADED)
-	      && !solib_used (current_program_space, *gdb_iter))
+	      && !still_in_use)
 	    gdb_iter->objfile->unlink ();
 
+	  current_program_space->deleted_solibs.push_back (gdb_iter->so_name);
+
 	  /* Some targets' section tables might be referring to
 	     sections from so.abfd; remove them.  */
 	  current_program_space->remove_target_sections (&*gdb_iter);
@@ -1158,7 +1167,10 @@  clear_solib (program_space *pspace)
 
   for (solib &so : pspace->so_list)
     {
-      notify_solib_unloaded (pspace, so);
+      bool still_in_use
+	= (so.objfile != nullptr && solib_used (pspace, so));
+
+      notify_solib_unloaded (pspace, so, still_in_use);
       pspace->remove_target_sections (&so);
     };
 
diff --git a/gdb/testsuite/gdb.base/dlmopen.exp b/gdb/testsuite/gdb.base/dlmopen.exp
index f1da76a13f6..14f9084dd6f 100644
--- a/gdb/testsuite/gdb.base/dlmopen.exp
+++ b/gdb/testsuite/gdb.base/dlmopen.exp
@@ -88,6 +88,18 @@  if { [build_executable "failed to build" $testfile $srcfile \
 set bp_inc [gdb_get_line_number "bp.inc" $srcfile_lib]
 set bp_main [gdb_get_line_number "bp.main" $srcfile]
 
+# Figure out the file name for the dynamic linker.
+set dyln_name [section_get $binfile .interp]
+if { $dyln_name eq "" } {
+    unsupported "couldn't find dynamic linker name"
+    return
+}
+
+# Return true if FILENAME is the dynamic linker.  Otherwise return false.
+proc is_dyln { filename } {
+    return [expr {$filename eq $::dyln_name}]
+}
+
 # Check that 'info shared' show NUM occurrences of DSO.
 proc check_dso_count { dso num } {
     global gdb_prompt hex
@@ -210,6 +222,161 @@  proc test_dlmopen_with_attach {} {
     }
 }
 
+# Run 'info sharedlibrary' and count the number of mappings that look
+# like they might be the dynamic linker.  This will only work for
+# Linux right now.
+proc get_dyld_info {} {
+    if { ![istarget *-linux*] } {
+	return [list 0 ""]
+    }
+
+    set dyld_count 0
+    set dyld_start_addr ""
+    gdb_test_multiple "info sharedlibrary" "" {
+	-re "From\\s+To\\s+Syms\\s+Read\\s+Shared Object Library\r\n" {
+	    exp_continue
+	}
+	-re "^($::hex)\\s+$::hex\\s+\[^/\]+(/\[^\r\n\]+)\r\n" {
+	    set addr $expect_out(1,string)
+	    set lib $expect_out(2,string)
+
+	    if { [is_dyln $lib] } {
+		# This looks like it might be the dynamic linker.
+		incr dyld_count
+		if { $dyld_start_addr eq "" } {
+		    set dyld_start_addr $addr
+		} elseif { $dyld_start_addr ne $addr } {
+		    set dyld_start_addr "MULTIPLE"
+		}
+	    }
+
+	    exp_continue
+	}
+	-re "\\(\\*\\): Shared library is missing debugging information\\.\r\n" {
+	    exp_continue
+	}
+	-re "^$::gdb_prompt $" {
+	}
+    }
+
+    if { $dyld_start_addr eq "MULTIPLE" } {
+	set dyld_start_addr ""
+    }
+
+    return [list $dyld_count $dyld_start_addr]
+}
+
+# The inferior for this test causes the dynamic linker to be appear
+# multiple times in the inferior's shared library list, but (at least
+# with glibc), the dynamic linker is really only mapped in once.  That
+# is, each of the dynamic linker instances that appear in the 'info
+# sharedlibrary' output, will have the same address range.
+#
+# This test creates a user breakpoint in the dynamic linker, and then
+# runs over the dlcose calls, which unmap all but one of the dynamic
+# linker instances.
+#
+# The expectation is that the user breakpoint in the dynamic linker
+# should still be active.  Older versions of GDB had a bug where the
+# breakpoint would become pending.
+proc_with_prefix test_solib_unmap_events { } {
+
+    # This test relies on finding the dynamic linker library, and is
+    # currently written assuming Linux.
+    if { ![istarget *-linux*] } {
+	unsupport "cannot find dynamic linker library on this target"
+	return
+    }
+
+    clean_restart $::binfile
+
+    if { ![runto_main] } {
+	return
+    }
+
+    # Check that before any of our dlopen/dlmopen calls, we can find a
+    # single copy of the dynamic linker in the shared library list.
+    set dyld_info [get_dyld_info]
+    set dyld_count [lindex $dyld_info 0]
+    if { $dyld_count != 1 } {
+	unsupported "initial dyld state appears strange"
+	return
+    }
+
+    # Continue the inferior until all solib are loaded.
+    set alarm_lineno [gdb_get_line_number "alarm" $::srcfile]
+    gdb_breakpoint ${::srcfile}:${alarm_lineno}
+    gdb_continue_to_breakpoint "all solib are now loaded"
+
+    # Check that we have multiple copies of dynamic linker loaded, and
+    # that the dynamic linker is only loaded at a single address.
+    set dyld_info [get_dyld_info]
+    set dyld_count [lindex $dyld_info 0]
+    set dyld_start_addr [lindex $dyld_info 1]
+
+    # If we didn't find a suitable dynamic linker address, or we
+    # didn't find multiple copies of the dynamic linker, then
+    # something has gone wrong with the test setup.
+    if { $dyld_count < 2 } {
+	unsupported "multiple copies of the dynamic linker not found"
+	return
+    }
+    if { $dyld_start_addr eq "" } {
+	unsupported "unable to find suitable dynamic linker start address"
+	return
+    }
+
+    # Check the address we found is (likely) writable.
+    gdb_test_multiple "x/1i $dyld_start_addr" "check b/p address" {
+	-re -wrap "Cannot access memory at address \[^\r\n\]+" {
+	    unsupported "dynamic linker address is not accessible"
+	    return
+	}
+	-re -wrap "" {
+	}
+    }
+
+    # Create a breakpoint within the dynamic linker.  It is pretty unlikely
+    # that this breakpoint will ever be hit, but just in case it is, make it
+    # conditional, with a condition that will never be true.  All we really
+    # care about for this test is whether the breakpoint will be made
+    # pending or not (it should not).
+    gdb_test "break *$dyld_start_addr if (0)" \
+	"Breakpoint $::decimal at $::hex\[^\r\n\]+" \
+	"create breakpoint within dynamic linker"
+    set bpnum [get_integer_valueof "\$bpnum" INVALID "get bpnum"]
+
+    # Now continue until the 'bp.main' location, this will unload some
+    # copies, but not all copies, of the dynamic linker.
+    gdb_test "print wait_for_gdb = 0" " = 0"
+    set bp_main [gdb_get_line_number "bp.main" $::srcfile]
+
+    gdb_breakpoint $::srcfile:$bp_main
+    gdb_continue_to_breakpoint "stop at bp.main"
+
+    # At one point, GDB would incorrectly mark the breakpoints in the
+    # dynamic linker as pending when some instances of the library were
+    # unloaded, despite there really only being one copy of the dynamic
+    # linker actually loaded into the inferior's address space.
+    gdb_test_multiple "info breakpoints $bpnum" "check b/p status" {
+	-re -wrap "$bpnum\\s+breakpoint\\s+keep\\s+y\\s+<PENDING>\\s+\\*$::hex\\s*\r\n\\s+stop only if \\(0\\)" {
+	    fail $gdb_test_name
+	}
+
+	-re -wrap "$bpnum\\s+breakpoint\\s+keep\\s+y\\s+$::hex\\s*\[^\r\n\]+\r\n\\s+stop only if \\(0\\)" {
+	    pass $gdb_test_name
+	}
+    }
+
+    # With all the dlclose calls now complete, we should be back to a
+    # single copy of the dynamic linker.
+    set dyld_info [get_dyld_info]
+    set dyld_count [lindex $dyld_info 0]
+    gdb_assert { $dyld_count == 1 } \
+	"one dynamic linker found after dlclose calls"
+}
+
 # Run the actual tests.
 test_dlmopen_no_attach
 test_dlmopen_with_attach
+test_solib_unmap_events
diff --git a/gdb/testsuite/gdb.mi/mi-dlmopen-lib-dep.c b/gdb/testsuite/gdb.mi/mi-dlmopen-lib-dep.c
new file mode 100644
index 00000000000..1645f55b865
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/mi-dlmopen-lib-dep.c
@@ -0,0 +1,21 @@ 
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2021-2024 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+__attribute__((visibility ("default")))
+int gdb_dlmopen_glob = 1;
diff --git a/gdb/testsuite/gdb.mi/mi-dlmopen-lib.c b/gdb/testsuite/gdb.mi/mi-dlmopen-lib.c
new file mode 100644
index 00000000000..4ce9280bad3
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/mi-dlmopen-lib.c
@@ -0,0 +1,28 @@ 
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2021-2024 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+extern int gdb_dlmopen_glob;
+
+__attribute__((visibility ("default")))
+int
+inc (int n)
+{
+  int amount = gdb_dlmopen_glob;
+  return n + amount;  /* bp.inc.  */
+}
diff --git a/gdb/testsuite/gdb.mi/mi-dlmopen.c b/gdb/testsuite/gdb.mi/mi-dlmopen.c
new file mode 100644
index 00000000000..d3853f8d9e5
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/mi-dlmopen.c
@@ -0,0 +1,59 @@ 
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2021-2024 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+*/
+
+#define _GNU_SOURCE
+#include <dlfcn.h>
+#include <stddef.h>
+#include <assert.h>
+#include <unistd.h>
+
+int
+main (void)
+{
+  void *handle[4];
+  int (*fun) (int);
+  Lmid_t lmid;
+  int dl;
+
+  handle[0] = dlmopen (LM_ID_NEWLM, DSO1_NAME, RTLD_LAZY | RTLD_LOCAL);
+  assert (handle[0] != NULL);
+
+  dlinfo (handle[0], RTLD_DI_LMID, &lmid);
+
+  handle[1] = dlopen (DSO1_NAME, RTLD_LAZY | RTLD_LOCAL);
+  assert (handle[1] != NULL);
+
+  handle[2] = dlmopen (LM_ID_NEWLM, DSO1_NAME, RTLD_LAZY | RTLD_LOCAL);
+  assert (handle[2] != NULL);
+
+  handle[3] = dlmopen (lmid, DSO2_NAME, RTLD_LAZY | RTLD_LOCAL);
+  assert (handle[3] != NULL);	/* bp.loaded */
+
+  for (dl = 0; dl < 4; ++dl)
+    {
+      fun = dlsym (handle[dl], "inc");
+      assert (fun != NULL);
+
+      fun (42);
+
+      dlclose (handle[dl]);
+    }
+
+  return 0;  /* bp.main  */
+}
diff --git a/gdb/testsuite/gdb.mi/mi-dlmopen.exp b/gdb/testsuite/gdb.mi/mi-dlmopen.exp
new file mode 100644
index 00000000000..77d166273e3
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/mi-dlmopen.exp
@@ -0,0 +1,209 @@ 
+# This testcase is part of GDB, the GNU debugger.
+#
+# Copyright 2024 Free Software Foundation, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+# MI tests related to loading shared libraries into different namespaces
+# with dlmopen().  The source files for this test are copied (almost)
+# verbatim from the gdb.base/dlmopen.exp test.
+
+load_lib "mi-support.exp"
+
+require allow_dlmopen_tests
+
+standard_testfile .c -lib.c -lib-dep.c
+
+set basename_lib dlmopen-lib
+set srcfile_lib $srcfile2
+set binfile_lib1 [standard_output_file $basename_lib.1.so]
+set binfile_lib2 [standard_output_file $basename_lib.2.so]
+set srcfile_lib_dep $srcfile3
+set binfile_lib_dep [standard_output_file $basename_lib-dep.so]
+
+if { [build_executable "build shlib dep" $binfile_lib_dep $srcfile_lib_dep \
+	  {debug shlib}] == -1 } {
+    return
+}
+
+if { [build_executable "build shlib" $binfile_lib1 $srcfile_lib \
+	  [list debug shlib_load shlib libs=$binfile_lib_dep]] == -1 } {
+    return
+}
+
+if { [build_executable "build shlib" $binfile_lib2 $srcfile_lib \
+	  [list debug shlib_load shlib libs=$binfile_lib_dep]] == -1 } {
+    return
+}
+
+if { [build_executable "failed to build" $testfile $srcfile \
+	  [list additional_flags=-DDSO1_NAME=\"$binfile_lib1\" \
+	       additional_flags=-DDSO2_NAME=\"$binfile_lib2\" \
+	       shlib_load debug]] } {
+    return
+}
+
+# Figure out the file name for the dynamic linker.
+set dyln_name [section_get $binfile .interp]
+if { $dyln_name eq "" } {
+    unsupported "couldn't find dynamic linker name"
+    return
+}
+
+# Some source locations needed by the tests.
+set bp_main [gdb_get_line_number "bp.main" $srcfile]
+set bp_loaded [gdb_get_line_number "bp.loaded" $srcfile]
+
+# Return true if FILENAME is the dynamic linker.  Otherwise return false.
+proc is_dyln { filename } {
+    return [expr {$filename eq $::dyln_name}]
+}
+
+# Run 'info sharedlibrary' and count the number of mappings that look
+# like they might be the dynamic linker.  This will only work for
+# Linux right now.
+proc get_dyld_info {} {
+    if { ![istarget *-linux*] } {
+	return [list 0 ""]
+    }
+
+    set dyld_count 0
+    set dyld_start_addr ""
+    gdb_test_multiple "info sharedlibrary" "" {
+	-re "~\"From\\s+To\\s+Syms\\s+Read\\s+Shared Object Library\\\\n\"\r\n" {
+	    exp_continue
+	}
+	-re "^~\"($::hex)\\s+$::hex\\s+\[^/\]+(/\[^\r\n\]+)\\\\n\"\r\n" {
+	    set addr $expect_out(1,string)
+	    set lib $expect_out(2,string)
+
+	    if { [is_dyln $lib] } {
+		# This looks like it might be the dynamic linker.
+		incr dyld_count
+		if { $dyld_start_addr eq "" } {
+		    set dyld_start_addr $addr
+		} elseif { $dyld_start_addr ne $addr } {
+		    set dyld_start_addr "MULTIPLE"
+		}
+	    }
+
+	    exp_continue
+	}
+	-re "~\"\\(\\*\\): Shared library is missing debugging information\\.\\\\n\"\r\n" {
+	    exp_continue
+	}
+	-re "^\\^done\r\n" {
+	    exp_continue
+	}
+	-re "^$::mi_gdb_prompt$" {
+	}
+    }
+
+    if { $dyld_start_addr eq "MULTIPLE" } {
+	set dyld_start_addr ""
+    }
+
+    return [list $dyld_count $dyld_start_addr]
+}
+
+# Run the inferior over all the 'dlclose' calls and capture the
+# resulting library-unloaded events.  Check that we see the expected
+# number of unload events for the libraries created for this test, and
+# additionally, check for dynamic linker unload events.
+proc check_solib_unload_events {} {
+    mi_clean_restart $::binfile
+
+    if {[mi_runto_main] == -1} {
+	return
+    }
+
+    # After starting we expect the dynamic linker to be loaded exactly
+    # once.  If it is not then we'll not be able to check the dynamic
+    # linker unloaded events later in this script.
+    set dyld_info [get_dyld_info]
+    set dyld_count [lindex $dyld_info 0]
+    if { $dyld_count != 1 } {
+	unsupported "dynamic linker doesn't appear to be loaded"
+	return
+    }
+
+    # Create breakpoints.
+    mi_create_breakpoint "$::srcfile:$::bp_loaded" \
+	"create b/p once libraries are loaded" \
+	-disp keep -func main -file ".*$::srcfile" -line $::bp_loaded
+    mi_create_breakpoint "$::srcfile:$::bp_main" "create b/p at dlclose" \
+	-disp keep -func main -file ".*$::srcfile" -line $::bp_main
+
+    # Run past all the dlopen and dlmopen calls.
+    mi_execute_to "exec-continue" "breakpoint-hit" main "" ".*" $::bp_loaded \
+	{"" "disp=\"keep\""} "continue until all libraries are loaded"
+
+    # Check that the dynamic linker has now been loaded multiple times.
+    set dyld_info [get_dyld_info]
+    set dyld_count [lindex $dyld_info 0]
+    if { $dyld_count < 2 } {
+	unsupported "not enough instances of the dynamic linker are mapped in"
+	return
+    }
+
+    # Continue.  This will run until the end of 'main', and will pass
+    # over all the dlclose calls.
+    if {[mi_send_resuming_command "exec-continue" "exec-next"] == -1} {
+	return
+    }
+
+    # As a result of all the dlclose calls we should see some library
+    # unload events.  Process them now.
+    set dyld_unload_count 0
+    array set unload_counts {}
+    gdb_test_multiple "" "" -prompt $::mi_gdb_prompt {
+	-re "=library-unloaded,id=\"(\[^\"\]+)\",\[^\r\n\]+\r\n" {
+	    set lib $expect_out(1,string)
+	    if {[is_dyln $lib]} {
+		# This is the dynamic linker being unloaded.
+		incr dyld_unload_count
+	    }
+	    set filename [file tail $lib]
+	    incr unload_counts($filename)
+	    exp_continue
+	}
+	-re "\\*stopped,reason=\"breakpoint-hit\",\[^\r\n\]+\r\n$::mi_gdb_prompt" {
+	}
+    }
+
+    # Check we saw the dynamic linker being unloaded the expected number of
+    # times.
+    gdb_assert { $dyld_unload_count == $dyld_count - 1 } \
+	"expected number of dynamic linker unloads"
+
+    # Check that we saw the expected number of library-unloaded events for
+    # each library.  Each DESC is a list of two elements, a filename for a
+    # library, and the number of times it should have been unloaded.
+    foreach desc [list [list $::binfile_lib1 3] \
+		       [list $::binfile_lib_dep 3] \
+		       [list $::binfile_lib2 1]] {
+	set filename [file tail [lindex $desc 0]]
+	set count [lindex $desc 1]
+	gdb_assert { $unload_counts($filename) == $count } \
+	    "check unload count for $filename"
+    }
+
+    # Check that the dynamic linker still shows as loaded exactly once.
+    set dyld_info [get_dyld_info]
+    set dyld_count [lindex $dyld_info 0]
+    gdb_assert { $dyld_count == 1 } \
+	"dynamic linker is mapped once at final b/p"
+}
+
+check_solib_unload_events
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 7ee2043f0f8..dca3d5f2b63 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -10963,5 +10963,38 @@  gdb_caching_proc root_user {} {
     return [expr $uid == 0]
 }
 
+# Return nul-terminated string read from section SECTION of EXEC.  Return ""
+# if no such section or nul-terminated string was found.  Function is useful
+# for sections ".interp" or ".gnu_debuglink".
+
+proc section_get {exec section} {
+    global subdir
+    set tmp [standard_output_file section_get.tmp]
+    set objcopy_program [gdb_find_objcopy]
+
+    set command "exec $objcopy_program -O binary --set-section-flags $section=A --change-section-address $section=0 -j $section $exec $tmp"
+    verbose -log "command is $command"
+    set result [catch $command output]
+    verbose -log "result is $result"
+    verbose -log "output is $output"
+    if {$result == 1} {
+	return ""
+    }
+    set fi [open $tmp]
+    fconfigure $fi -translation binary
+    set data [read $fi]
+    close $fi
+    file delete $tmp
+    # .interp has size $len + 1 but .gnu_debuglink contains garbage after \000.
+    set len [string first \000 $data]
+    if {$len < 0} {
+	verbose -log "section $section not found"
+	return ""
+    }
+    set retval [string range $data 0 [expr $len - 1]]
+    verbose -log "section $section is <$retval>"
+    return $retval
+}
+
 # Always load compatibility stuff.
 load_lib future.exp
diff --git a/gdb/testsuite/lib/prelink-support.exp b/gdb/testsuite/lib/prelink-support.exp
index 894af399bce..3aaea0a36ed 100644
--- a/gdb/testsuite/lib/prelink-support.exp
+++ b/gdb/testsuite/lib/prelink-support.exp
@@ -13,39 +13,6 @@ 
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-# Return nul-terminated string read from section SECTION of EXEC.  Return ""
-# if no such section or nul-terminated string was found.  Function is useful
-# for sections ".interp" or ".gnu_debuglink".
-
-proc section_get {exec section} {
-    global subdir
-    set tmp [standard_output_file section_get.tmp]
-    set objcopy_program [gdb_find_objcopy]
-
-    set command "exec $objcopy_program -O binary --set-section-flags $section=A --change-section-address $section=0 -j $section $exec $tmp"
-    verbose -log "command is $command"
-    set result [catch $command output]
-    verbose -log "result is $result"
-    verbose -log "output is $output"
-    if {$result == 1} {
-	return ""
-    }
-    set fi [open $tmp]
-    fconfigure $fi -translation binary
-    set data [read $fi]
-    close $fi
-    file delete $tmp
-    # .interp has size $len + 1 but .gnu_debuglink contains garbage after \000.
-    set len [string first \000 $data]
-    if {$len < 0} {
-	verbose -log "section $section not found"
-	return ""
-    }
-    set retval [string range $data 0 [expr $len - 1]]
-    verbose -log "section $section is <$retval>"
-    return $retval
-}
-
 # Resolve symlinks.
 
 proc symlink_resolve {file} {