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authorAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-02-12 12:36:46 -0200
committerAdhemerval Zanella <adhemerval.zanella@linaro.org>2019-02-14 18:11:15 -0200
commiteb76e5b465a4b7b569cde4b4f57d1fcb4695c1c6 (patch)
treeaff02c87506c03b3492731e636584bd26fdd3895 /sysdeps/unix/sysv/linux/lowlevellock-futex.h
parent20d0195c714fe847183e4a303e55f4ae1242aecf (diff)
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nptl: Reinstate pthread_timedjoin_np as a cancellation point (BZ#24215)
Patch ce7eb0e90315 ("nptl: Cleanup cancellation macros") changed the
join sequence for internal common __pthread_timedjoin_ex to use the
new macro lll_wait_tid.  The idea was this macro would issue the
cancellable futex operation depending whether the timeout is used or
not.  However if a timeout is used, __lll_timedwait_tid is called and
it is not a cancellable entrypoint.

This patch fixes it by simplifying the code in various ways:

  - Instead of adding the cancellation handling on __lll_timedwait_tid,
    it moves the generic implementation to pthread_join_common.c (called
    now timedwait_tid with some fixes to use the correct type for pid).

  - The llvm_wait_tid macro is removed, along with its replication on
    x86_64, i686, and sparc arch-specific lowlevellock.h.

  - sparc32 __lll_timedwait_tid is also removed, since the code is similar
    to generic one.

  - x86_64 and i386 provides arch-specific __lll_timedwait_tid which is
    also removed since they are similar in functionality to generic C code
    and there is no indication it is better than compiler generated code.

New tests, tst-join8 and tst-join9, are provided to check if
pthread_timedjoin_np acts as a cancellation point.

Checked on x86_64-linux-gnu, i686-linux-gnu, sparcv9-linux-gnu, and
aarch64-linux-gnu.

	[BZ #24215]
	* nptl/Makefile (lpthread-routines): Remove lll_timedwait_tid.
	(tests): Add tst-join8 tst-join9.
	* nptl/lll_timedwait_tid.c: Remove file.
	* sysdeps/sparc/sparc32/lll_timedwait_tid.c: Likewise.
	* sysdeps/unix/sysv/linux/i386/lll_timedwait_tid.c: Likewise.
	* sysdeps/sysv/linux/x86_64/lll_timedwait_tid.c: Likewise.
	* nptl/pthread_join_common.c (timedwait_tid): New function.
	(__pthread_timedjoin_ex): Act as cancellation entrypoint is block
	is set.
	* nptl/tst-join5.c (thread_join): New function.
	(tf1, tf2, do_test): Use libsupport and add pthread_timedjoin_np
	check.
	* nptl/tst-join8.c: New file.
	* nptl/tst-join9.c: Likewise.
	* sysdeps/nptl/lowlevellock-futex.h (lll_futex_wait_cancel,
	lll_futex_timed_wait_cancel): Add generic macros.
	* sysdeps/nptl/lowlevellock.h (__lll_timedwait_tid, lll_wait_tid):
	Remove definitions.
	* sysdeps/unix/sysv/linux/i386/lowlevellock.h: Likewise.
	* sysdeps/unix/sysv/linux/sparc/lowlevellock.h: Likewise.
	* sysdeps/unix/sysv/linux/x86_64/lowlevellock.h: Likewise.
	* sysdeps/sparc/sparc32/lowlevellock.c (__lll_timedwait_tid):
	Remove function.
	* sysdeps/unix/sysv/linux/i386/lowlevellock.S (__lll_timedwait_tid):
	Likewise.
	* sysdeps/unix/sysv/linux/x86_64/lowlevellock.S: Likewise.
	* sysdeps/unix/sysv/linux/lowlevellock-futex.h
	(lll_futex_timed_wait_cancel): New macro.
Diffstat (limited to 'sysdeps/unix/sysv/linux/lowlevellock-futex.h')
-rw-r--r--sysdeps/unix/sysv/linux/lowlevellock-futex.h7
1 files changed, 7 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/lowlevellock-futex.h b/sysdeps/unix/sysv/linux/lowlevellock-futex.h
index 8ca3417aaa..6f060b1739 100644
--- a/sysdeps/unix/sysv/linux/lowlevellock-futex.h
+++ b/sysdeps/unix/sysv/linux/lowlevellock-futex.h
@@ -135,6 +135,13 @@
     __err;							       \
   })
 
+#define lll_futex_timed_wait_cancel(futexp, val, timeout, private)	   \
+  ({									   \
+    int __oldtype = CANCEL_ASYNC ();				       	   \
+    long int __err = lll_futex_timed_wait (futexp, val, timeout, private); \
+    CANCEL_RESET (__oldtype);						   \
+    __err;								   \
+  })
 
 #endif  /* !__ASSEMBLER__  */