libc: Extend __libc_freeres framework (Bug 23329).

The __libc_freeres framework does not extend to non-libc.so objects.
This causes problems in general for valgrind and mtrace detecting
unfreed objects in both libdl.so and libpthread.so.  This change is
a pre-requisite to properly moving the malloc hooks out of malloc
since such a move now requires precise accounting of all allocated
data before destructors are run.

This commit adds a proper hook in libc.so.6 for both libdl.so and
for libpthread.so, this ensures that shm-directory.c which uses
freeit () to free memory is called properly.  We also remove the
nptl_freeres hook and fall back to using weak-ref-and-check idiom
for a loaded libpthread.so, thus making this process similar for
all DSOs.

Lastly we follow best practice and use explicit free calls for
both libdl.so and libpthread.so instead of the generic hook process
which has undefined order.

Tested on x86_64 with no regressions.

Signed-off-by: DJ Delorie <dj@redhat.com>
Signed-off-by: Carlos O'Donell <carlos@redhat.com>

4 files changed, 7 insertions, 7 deletions

diff --git a/sysdeps/mach/strerror_l.c b/sysdeps/mach/strerror_l.c
index b9842ccf40..7111124439 100644
--- a/sysdeps/mach/strerror_l.c
+++ b/sysdeps/mach/strerror_l.c
@@ -24,6 +24,7 @@
 #include <mach/error.h>
 #include <errorlib.h>
 #include <sys/param.h>
+#include <libc-symbols.h>
 
 
 static __thread char *last_value;
@@ -86,7 +87,7 @@ strerror_l (int errnum, locale_t loc)
   return (char *) translate (es->subsystem[sub].codes[code], loc);
 }
 
-
+/* This is called when a thread is exiting to free the last_value string.  */
 void
 __strerror_thread_freeres (void)
 {
diff --git a/sysdeps/nptl/pthread-functions.h b/sysdeps/nptl/pthread-functions.h
index 53a4b38fbc..fa103695d9 100644
--- a/sysdeps/nptl/pthread-functions.h
+++ b/sysdeps/nptl/pthread-functions.h
@@ -94,7 +94,6 @@ struct pthread_functions
        __attribute ((noreturn)) __cleanup_fct_attribute;
   void (*ptr__nptl_deallocate_tsd) (void);
   int (*ptr__nptl_setxid) (struct xid_command *);
-  void (*ptr_freeres) (void);
   void (*ptr_set_robust) (struct pthread *);
 };
 
diff --git a/sysdeps/nptl/unwind-forcedunwind.c b/sysdeps/nptl/unwind-forcedunwind.c
index 0621c8002f..5902fa4be7 100644
--- a/sysdeps/nptl/unwind-forcedunwind.c
+++ b/sysdeps/nptl/unwind-forcedunwind.c
@@ -79,9 +79,9 @@ pthread_cancel_init (void)
   libgcc_s_handle = handle;
 }
 
+/* Register for cleanup in libpthread.so.  */
 void
-__libc_freeres_fn_section
-__unwind_freeres (void)
+__nptl_unwind_freeres (void)
 {
   void *handle = libgcc_s_handle;
   if (handle != NULL)
diff --git a/sysdeps/unix/sysv/linux/shm-directory.c b/sysdeps/unix/sysv/linux/shm-directory.c
index c494d3fbf6..6a7c7fd182 100644
--- a/sysdeps/unix/sysv/linux/shm-directory.c
+++ b/sysdeps/unix/sysv/linux/shm-directory.c
@@ -135,13 +135,13 @@ __shm_directory (size_t *len)
 }
 #if IS_IN (libpthread)
 hidden_def (__shm_directory)
-#endif
-
 
 /* Make sure the table is freed if we want to free everything before
    exiting.  */
-libc_freeres_fn (freeit)
+void
+__shm_directory_freeres (void)
 {
   if (mountpoint.dir != defaultdir)
     free (mountpoint.dir);
 }
+#endif