nptl: Move legacy unwinding implementation into libc

It is still used internally.  Since unwinding is now available
unconditionally, avoid indirect calls through function pointers loaded
from the stack by inlining the non-cancellation cleanup code.  This
avoids a regression in security hardening.

The out-of-line  __libc_cleanup_routine implementation is no longer
needed because the inline definition is now static __always_inline.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

1 files changed, 1 insertions, 25 deletions

diff --git a/sysdeps/nptl/libc-lockP.h b/sysdeps/nptl/libc-lockP.h
index 63b605dee2..2c928b7a76 100644
--- a/sysdeps/nptl/libc-lockP.h
+++ b/sysdeps/nptl/libc-lockP.h
@@ -251,32 +251,12 @@ _Static_assert (LLL_LOCK_INITIALIZER == 0, "LLL_LOCK_INITIALIZER != 0");
 /* Get once control variable.  */
 #define __libc_once_get(ONCE_CONTROL)	((ONCE_CONTROL) != PTHREAD_ONCE_INIT)
 
-/* Note that for I/O cleanup handling we are using the old-style
-   cancel handling.  It does not have to be integrated with C++ snce
-   no C++ code is called in the middle.  The old-style handling is
-   faster and the support is not going away.  */
-extern void _pthread_cleanup_push (struct _pthread_cleanup_buffer *buffer,
-				   void (*routine) (void *), void *arg);
-extern void _pthread_cleanup_pop (struct _pthread_cleanup_buffer *buffer,
-				  int execute);
-extern void _pthread_cleanup_push_defer (struct _pthread_cleanup_buffer *buffer,
-					 void (*routine) (void *), void *arg);
-extern void _pthread_cleanup_pop_restore (struct _pthread_cleanup_buffer *buffer,
-					  int execute);
-
-/* Sometimes we have to exit the block in the middle.  */
-#define __libc_cleanup_end(DOIT) \
-    if (_avail) {							      \
-      __libc_ptf_call_always (_pthread_cleanup_pop_restore, (&_buffer, DOIT));\
-    } else if (DOIT)							      \
-      _buffer.__routine (_buffer.__arg)
-
 /* __libc_cleanup_push and __libc_cleanup_pop depend on exception
    handling and stack unwinding.  */
 #ifdef __EXCEPTIONS
 
 /* Normal cleanup handling, based on C cleanup attribute.  */
-__extern_inline void
+static __always_inline void
 __libc_cleanup_routine (struct __pthread_cleanup_frame *f)
 {
   if (f->__do_it)
@@ -388,8 +368,6 @@ weak_extern (__pthread_once)
 weak_extern (__pthread_initialize)
 weak_extern (__pthread_atfork)
 weak_extern (__pthread_setcancelstate)
-weak_extern (_pthread_cleanup_push_defer)
-weak_extern (_pthread_cleanup_pop_restore)
 # else
 #  pragma weak __pthread_mutex_init
 #  pragma weak __pthread_mutex_destroy
@@ -412,8 +390,6 @@ weak_extern (_pthread_cleanup_pop_restore)
 #  pragma weak __pthread_initialize
 #  pragma weak __pthread_atfork
 #  pragma weak __pthread_setcancelstate
-#  pragma weak _pthread_cleanup_push_defer
-#  pragma weak _pthread_cleanup_pop_restore
 # endif
 #endif