public inbox for libc-alpha@sourceware.org
 help / color / mirror / Atom feed
* [PATCH 1/2] nptl: Remove __ASSUME_SET_ROBUST_LIST
@ 2016-09-21 14:11 Adhemerval Zanella
  2016-09-21 14:11 ` [PATCH 2/2] linux: Remove __ASSUME_SET_ROBUST_LIST defines Adhemerval Zanella
  0 siblings, 1 reply; 16+ messages in thread
From: Adhemerval Zanella @ 2016-09-21 14:11 UTC (permalink / raw)
  To: libc-alpha

This patch removes the __ASSUME_SET_ROBUST_LIST usage on nptl generic
code.  The set_robust_list availability is defined by '__set_robust_list_avail'
which is now defined regardless.  Its initial value is set to -1 and
defined to a positive value if both __NR_set_robust_list is defined
and the syscall returns correctly.

A subsequent patch is intended to remove the Linux definitions of
__ASSUME_SET_ROBUST_LIST.

Tested on x86_64.

	* nptl/nptl-init.c (set_robust_list_not_avail): Remove definition.
	(__pthread_initialize_minimal_internal): Set __set_robust_list_avail
	to 1 if syscall returns correctly.
	(__set_robust_list_avail): Define regardless if
	__ASSUME_SET_ROBUST_LIST is defined or not.
	* nptl/pthreadP.h (__set_robust_list_avail): Likewise.
	* nptl/pthread_create.c (START_THREAD_DEFN): Remove
	__ASSUME_SET_ROBUST_LIST usage.
	* nptl/pthread_mutex_init.c (__pthread_mutex_init): Likewise.
---
 nptl/nptl-init.c          | 12 +++---------
 nptl/pthreadP.h           |  2 --
 nptl/pthread_create.c     |  8 ++------
 nptl/pthread_mutex_init.c |  2 --
 4 files changed, 5 insertions(+), 19 deletions(-)

diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c
index bdbdfed..6dd658a 100644
--- a/nptl/nptl-init.c
+++ b/nptl/nptl-init.c
@@ -48,14 +48,8 @@ int *__libc_multiple_threads_ptr attribute_hidden;
 size_t __static_tls_size;
 size_t __static_tls_align_m1;
 
-#ifndef __ASSUME_SET_ROBUST_LIST
 /* Negative if we do not have the system call and we can use it.  */
-int __set_robust_list_avail;
-# define set_robust_list_not_avail() \
-  __set_robust_list_avail = -1
-#else
-# define set_robust_list_not_avail() do { } while (0)
-#endif
+int __set_robust_list_avail = -1;
 
 #ifndef __ASSUME_FUTEX_CLOCK_REALTIME
 /* Nonzero if we do not have FUTEX_CLOCK_REALTIME.  */
@@ -335,9 +329,9 @@ __pthread_initialize_minimal_internal (void)
     INTERNAL_SYSCALL_DECL (err);
     int res = INTERNAL_SYSCALL (set_robust_list, err, 2, &pd->robust_head,
 				sizeof (struct robust_list_head));
-    if (INTERNAL_SYSCALL_ERROR_P (res, err))
+    if (!INTERNAL_SYSCALL_ERROR_P (res, err))
+      __set_robust_list_avail = 1;
 #endif
-      set_robust_list_not_avail ();
   }
 
 #ifdef __NR_futex
diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h
index 6e0dd09..0ce65f3 100644
--- a/nptl/pthreadP.h
+++ b/nptl/pthreadP.h
@@ -199,10 +199,8 @@ hidden_proto (__pthread_keys)
 /* Number of threads running.  */
 extern unsigned int __nptl_nthreads attribute_hidden;
 
-#ifndef __ASSUME_SET_ROBUST_LIST
 /* Negative if we do not have the system call and we can use it.  */
 extern int __set_robust_list_avail attribute_hidden;
-#endif
 
 /* Thread Priority Protection.  */
 extern int __sched_fifo_min_prio attribute_hidden;
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index a834063..04c5e7f 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -271,18 +271,16 @@ START_THREAD_DEFN
   if (__glibc_unlikely (atomic_exchange_acq (&pd->setxid_futex, 0) == -2))
     futex_wake (&pd->setxid_futex, 1, FUTEX_PRIVATE);
 
-#ifdef __NR_set_robust_list
-# ifndef __ASSUME_SET_ROBUST_LIST
   if (__set_robust_list_avail >= 0)
-# endif
     {
+#ifdef __NR_set_robust_list
       INTERNAL_SYSCALL_DECL (err);
       /* This call should never fail because the initial call in init.c
 	 succeeded.  */
       INTERNAL_SYSCALL (set_robust_list, err, 2, &pd->robust_head,
 			sizeof (struct robust_list_head));
-    }
 #endif
+    }
 
 #ifdef SIGCANCEL
   /* If the parent was running cancellation handlers while creating
@@ -388,7 +386,6 @@ START_THREAD_DEFN
      the breakpoint reports TD_THR_RUN state rather than TD_THR_ZOMBIE.  */
   atomic_bit_set (&pd->cancelhandling, EXITING_BIT);
 
-#ifndef __ASSUME_SET_ROBUST_LIST
   /* If this thread has any robust mutexes locked, handle them now.  */
 # ifdef __PTHREAD_MUTEX_HAVE_PREV
   void *robust = pd->robust_head.list;
@@ -419,7 +416,6 @@ START_THREAD_DEFN
 	}
       while (robust != (void *) &pd->robust_head);
     }
-#endif
 
   /* Mark the memory of the stack as usable to the kernel.  We free
      everything except for the space used for the TCB itself.  */
diff --git a/nptl/pthread_mutex_init.c b/nptl/pthread_mutex_init.c
index 6e5acb6..6aef890 100644
--- a/nptl/pthread_mutex_init.c
+++ b/nptl/pthread_mutex_init.c
@@ -91,11 +91,9 @@ __pthread_mutex_init (pthread_mutex_t *mutex,
 
   if ((imutexattr->mutexkind & PTHREAD_MUTEXATTR_FLAG_ROBUST) != 0)
     {
-#ifndef __ASSUME_SET_ROBUST_LIST
       if ((imutexattr->mutexkind & PTHREAD_MUTEXATTR_FLAG_PSHARED) != 0
 	  && __set_robust_list_avail < 0)
 	return ENOTSUP;
-#endif
 
       mutex->__data.__kind |= PTHREAD_MUTEX_ROBUST_NORMAL_NP;
     }
-- 
2.7.4

^ permalink raw reply	[flat|nested] 16+ messages in thread
* [PATCH 1/2] nptl: Remove __ASSUME_SET_ROBUST_LIST
@ 2017-04-18 21:13 Adhemerval Zanella
  2017-04-19  5:37 ` Florian Weimer
  0 siblings, 1 reply; 16+ messages in thread
From: Adhemerval Zanella @ 2017-04-18 21:13 UTC (permalink / raw)
  To: libc-alpha

This is another patch that was in my backlog, so I am sending it again
on the list since first version was send almost 5 months ago [1].

--

This patch removes the __ASSUME_SET_ROBUST_LIST usage on nptl generic
code.  The set_robust_list availability is defined by '__set_robust_list_avail'
which is now defined regardless.  Its initial value is set to -1 and
defined to a positive value if both __NR_set_robust_list is defined
and the syscall returns correctly.

A subsequent patch is intended to remove the Linux definitions of
__ASSUME_SET_ROBUST_LIST.

Tested on x86_64.

	* nptl/nptl-init.c (set_robust_list_not_avail): Remove definition.
	(__pthread_initialize_minimal_internal): Set __set_robust_list_avail
	to 1 if syscall returns correctly.
	(__set_robust_list_avail): Define regardless if
	__ASSUME_SET_ROBUST_LIST is defined or not.
	* nptl/pthreadP.h (__set_robust_list_avail): Likewise.
	* nptl/pthread_create.c (START_THREAD_DEFN): Remove
	__ASSUME_SET_ROBUST_LIST usage.
	* nptl/pthread_mutex_init.c (__pthread_mutex_init): Likewise.

[1] https://sourceware.org/ml/libc-alpha/2016-09/msg00373.html
---
 nptl/nptl-init.c          | 12 +++---------
 nptl/pthreadP.h           |  2 --
 nptl/pthread_create.c     |  8 ++------
 nptl/pthread_mutex_init.c |  2 --
 4 files changed, 5 insertions(+), 19 deletions(-)

diff --git a/nptl/nptl-init.c b/nptl/nptl-init.c
index 2921607..c86b35e 100644
--- a/nptl/nptl-init.c
+++ b/nptl/nptl-init.c
@@ -48,14 +48,8 @@ int *__libc_multiple_threads_ptr attribute_hidden;
 size_t __static_tls_size;
 size_t __static_tls_align_m1;
 
-#ifndef __ASSUME_SET_ROBUST_LIST
 /* Negative if we do not have the system call and we can use it.  */
-int __set_robust_list_avail;
-# define set_robust_list_not_avail() \
-  __set_robust_list_avail = -1
-#else
-# define set_robust_list_not_avail() do { } while (0)
-#endif
+int __set_robust_list_avail = -1;
 
 #ifndef __ASSUME_FUTEX_CLOCK_REALTIME
 /* Nonzero if we do not have FUTEX_CLOCK_REALTIME.  */
@@ -308,9 +302,9 @@ __pthread_initialize_minimal_internal (void)
     INTERNAL_SYSCALL_DECL (err);
     int res = INTERNAL_SYSCALL (set_robust_list, err, 2, &pd->robust_head,
 				sizeof (struct robust_list_head));
-    if (INTERNAL_SYSCALL_ERROR_P (res, err))
+    if (!INTERNAL_SYSCALL_ERROR_P (res, err))
+      __set_robust_list_avail = 1;
 #endif
-      set_robust_list_not_avail ();
   }
 
 #ifdef __NR_futex
diff --git a/nptl/pthreadP.h b/nptl/pthreadP.h
index 7fc1e50..4125e7f 100644
--- a/nptl/pthreadP.h
+++ b/nptl/pthreadP.h
@@ -213,10 +213,8 @@ hidden_proto (__pthread_keys)
 /* Number of threads running.  */
 extern unsigned int __nptl_nthreads attribute_hidden;
 
-#ifndef __ASSUME_SET_ROBUST_LIST
 /* Negative if we do not have the system call and we can use it.  */
 extern int __set_robust_list_avail attribute_hidden;
-#endif
 
 /* Thread Priority Protection.  */
 extern int __sched_fifo_min_prio attribute_hidden;
diff --git a/nptl/pthread_create.c b/nptl/pthread_create.c
index d0d7414..76b0ac4 100644
--- a/nptl/pthread_create.c
+++ b/nptl/pthread_create.c
@@ -387,18 +387,16 @@ START_THREAD_DEFN
   if (__glibc_unlikely (atomic_exchange_acq (&pd->setxid_futex, 0) == -2))
     futex_wake (&pd->setxid_futex, 1, FUTEX_PRIVATE);
 
-#ifdef __NR_set_robust_list
-# ifndef __ASSUME_SET_ROBUST_LIST
   if (__set_robust_list_avail >= 0)
-# endif
     {
+#ifdef __NR_set_robust_list
       INTERNAL_SYSCALL_DECL (err);
       /* This call should never fail because the initial call in init.c
 	 succeeded.  */
       INTERNAL_SYSCALL (set_robust_list, err, 2, &pd->robust_head,
 			sizeof (struct robust_list_head));
-    }
 #endif
+    }
 
 #ifdef SIGCANCEL
   /* If the parent was running cancellation handlers while creating
@@ -508,7 +506,6 @@ START_THREAD_DEFN
      the breakpoint reports TD_THR_RUN state rather than TD_THR_ZOMBIE.  */
   atomic_bit_set (&pd->cancelhandling, EXITING_BIT);
 
-#ifndef __ASSUME_SET_ROBUST_LIST
   /* If this thread has any robust mutexes locked, handle them now.  */
 # ifdef __PTHREAD_MUTEX_HAVE_PREV
   void *robust = pd->robust_head.list;
@@ -539,7 +536,6 @@ START_THREAD_DEFN
 	}
       while (robust != (void *) &pd->robust_head);
     }
-#endif
 
   /* Mark the memory of the stack as usable to the kernel.  We free
      everything except for the space used for the TCB itself.  */
diff --git a/nptl/pthread_mutex_init.c b/nptl/pthread_mutex_init.c
index 138e144..18724e8 100644
--- a/nptl/pthread_mutex_init.c
+++ b/nptl/pthread_mutex_init.c
@@ -91,11 +91,9 @@ __pthread_mutex_init (pthread_mutex_t *mutex,
 
   if ((imutexattr->mutexkind & PTHREAD_MUTEXATTR_FLAG_ROBUST) != 0)
     {
-#ifndef __ASSUME_SET_ROBUST_LIST
       if ((imutexattr->mutexkind & PTHREAD_MUTEXATTR_FLAG_PSHARED) != 0
 	  && __set_robust_list_avail < 0)
 	return ENOTSUP;
-#endif
 
       mutex->__data.__kind |= PTHREAD_MUTEX_ROBUST_NORMAL_NP;
     }
-- 
2.7.4

^ permalink raw reply	[flat|nested] 16+ messages in thread
end of thread, other threads:[~2017-04-20 17:25 UTC | newest]

Thread overview: 16+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2016-09-21 14:11 [PATCH 1/2] nptl: Remove __ASSUME_SET_ROBUST_LIST Adhemerval Zanella
2016-09-21 14:11 ` [PATCH 2/2] linux: Remove __ASSUME_SET_ROBUST_LIST defines Adhemerval Zanella
2017-04-18 21:13 [PATCH 1/2] nptl: Remove __ASSUME_SET_ROBUST_LIST Adhemerval Zanella
2017-04-19  5:37 ` Florian Weimer
2017-04-19 14:18   ` Adhemerval Zanella
2017-04-19 14:51     ` Andreas Schwab
2017-04-19 14:52       ` Adhemerval Zanella
2017-04-19 15:28     ` Florian Weimer
2017-04-19 17:38       ` Adhemerval Zanella
2017-04-19 18:09         ` Florian Weimer
2017-04-19 21:02           ` Adhemerval Zanella
2017-04-20 12:51           ` Adhemerval Zanella
2017-04-20 12:52             ` Florian Weimer
2017-04-20 13:09               ` Adhemerval Zanella
2017-04-20 13:47                 ` Florian Weimer
2017-04-20 17:25                   ` Adhemerval Zanella

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).