18 files changed, 129 insertions, 104 deletions
diff --git a/sysdeps/unix/sysv/linux/Makefile b/sysdeps/unix/sysv/linux/Makefile
index 8b340d4988..9d6a2de870 100644
--- a/sysdeps/unix/sysv/linux/Makefile
+++ b/sysdeps/unix/sysv/linux/Makefile
@@ -49,8 +49,8 @@ sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
 		  bits/mman-linux.h \
 		  bits/siginfo-arch.h bits/siginfo-consts-arch.h
 
-tests += tst-clone tst-clone2 tst-fanotify tst-personality tst-quota \
-	 tst-sync_file_range test-errno-linux
+tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
+	 tst-quota tst-sync_file_range test-errno-linux
 
 # Generate the list of SYS_* macros for the system calls (__NR_* macros).
 
diff --git a/sysdeps/unix/sysv/linux/aarch64/clone.S b/sysdeps/unix/sysv/linux/aarch64/clone.S
index 259ec073c5..905915a0f3 100644
--- a/sysdeps/unix/sysv/linux/aarch64/clone.S
+++ b/sysdeps/unix/sysv/linux/aarch64/clone.S
@@ -23,12 +23,6 @@
 #define _ERRNO_H	1
 #include <bits/errno.h>
 
-#define CLONE_VM_BIT      8
-#define CLONE_VM          (1 << CLONE_VM_BIT)
-
-#define CLONE_THREAD_BIT  16
-#define CLONE_THREAD      (1 << CLONE_THREAD_BIT)
-
 /* int clone(int (*fn)(void *arg),            x0
 	     void *child_stack,               x1
 	     int flags,                       x2
@@ -84,7 +78,8 @@ thread_start:
 	blr	x10
 
 	/* We are done, pass the return value through x0.  */
-	b	HIDDEN_JUMPTARGET(_exit)
+	mov	x8, #SYS_ify(exit)
+	svc	0x0
 	cfi_endproc
 	.size thread_start, .-thread_start
 
diff --git a/sysdeps/unix/sysv/linux/alpha/clone.S b/sysdeps/unix/sysv/linux/alpha/clone.S
index 20ae361c6b..550461fb3b 100644
--- a/sysdeps/unix/sysv/linux/alpha/clone.S
+++ b/sysdeps/unix/sysv/linux/alpha/clone.S
@@ -23,8 +23,6 @@
 #define _ERRNO_H	1
 #include <bits/errno.h>
 
-#define CLONE_VM	0x00000100
-
 /* int clone(int (*fn)(void *arg), void *child_stack, int flags,
 	     void *arg, pid_t *ptid, void *tls, pid_t *ctid);
 
@@ -100,13 +98,8 @@ thread_start:
 	jsr	ra, (pv)
 	ldgp	gp, 0(ra)
 
-	/* Call _exit rather than doing it inline for breakpoint purposes.  */
-	mov	v0, a0
-#ifdef PIC
-	bsr	ra, HIDDEN_JUMPTARGET(_exit)	!samegp
-#else
-	jsr	ra, HIDDEN_JUMPTARGET(_exit)
-#endif
+	ldiq	v0, __NR_exit
+	call_pal PAL_callsys
 
 	/* Die horribly.  */
 	.align	4
diff --git a/sysdeps/unix/sysv/linux/arm/clone.S b/sysdeps/unix/sysv/linux/arm/clone.S
index a309add895..055d1304d9 100644
--- a/sysdeps/unix/sysv/linux/arm/clone.S
+++ b/sysdeps/unix/sysv/linux/arm/clone.S
@@ -24,9 +24,6 @@
 #define _ERRNO_H	1
 #include <bits/errno.h>
 
-#define CLONE_VM      0x00000100
-#define CLONE_THREAD  0x00010000
-
 /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
 	     pid_t *ptid, struct user_desc *tls, pid_t *ctid); */
 
@@ -76,7 +73,8 @@ PSEUDO_END (__clone)
 	BLX (ip)
 
 	@ and we are done, passing the return value through r0
-	b	PLTJMP(HIDDEN_JUMPTARGET(_exit))
+	ldr	r7, =SYS_ify(exit)
+	swi	0x0
 
 	.fnend
 
diff --git a/sysdeps/unix/sysv/linux/hppa/clone.S b/sysdeps/unix/sysv/linux/hppa/clone.S
index d36b302199..8c43944c7a 100644
--- a/sysdeps/unix/sysv/linux/hppa/clone.S
+++ b/sysdeps/unix/sysv/linux/hppa/clone.S
@@ -148,10 +148,10 @@ ENTRY(__clone)
 	copy	%r4, %r19
 #endif
 	/* The call to _exit needs saved r19.  */
-	bl	_exit, %rp
-	copy	%ret0, %arg0
+	ble     0x100(%sr2, %r0)
+	ldi	__NR_exit, %r20
 
-	/* We should not return from _exit.
+	/* We should not return from exit.
            We do not restore r4, or the stack state.  */
 	iitlbp	%r0, (%sr0, %r0)
 
diff --git a/sysdeps/unix/sysv/linux/i386/clone.S b/sysdeps/unix/sysv/linux/i386/clone.S
index a4ba3e20ff..49c82d98b0 100644
--- a/sysdeps/unix/sysv/linux/i386/clone.S
+++ b/sysdeps/unix/sysv/linux/i386/clone.S
@@ -39,8 +39,6 @@
 #define __NR_clone 120
 #define SYS_clone 120
 
-#define CLONE_VM	0x00000100
-
         .text
 ENTRY (__clone)
 	/* Sanity check arguments.  */
diff --git a/sysdeps/unix/sysv/linux/ia64/clone2.S b/sysdeps/unix/sysv/linux/ia64/clone2.S
index 9b59473c80..3157ce92d6 100644
--- a/sysdeps/unix/sysv/linux/ia64/clone2.S
+++ b/sysdeps/unix/sysv/linux/ia64/clone2.S
@@ -74,11 +74,11 @@ ENTRY(__clone2)
 	mov b6=out1
 	br.call.dptk.many rp=b6	/* Call fn(arg) in the child 	*/
 	;;
-	mov out0=r8		/* Argument to _exit		*/
+	mov out0=r8		/* Argument to exit		*/
 	mov gp=loc0
-	.globl HIDDEN_JUMPTARGET(_exit)
-	br.call.dpnt.many rp=HIDDEN_JUMPTARGET(_exit)
-				/* call _exit with result from fn.	*/
+	mov r15=SYS_ify (exit)
+	.save rp, r0
+	break __BREAK_SYSCALL
 	ret			/* Not reached.		*/
 PSEUDO_END(__clone2)
 
diff --git a/sysdeps/unix/sysv/linux/m68k/clone.S b/sysdeps/unix/sysv/linux/m68k/clone.S
index a680191765..0894b2a362 100644
--- a/sysdeps/unix/sysv/linux/m68k/clone.S
+++ b/sysdeps/unix/sysv/linux/m68k/clone.S
@@ -24,8 +24,6 @@
 #include <bits/errno.h>
 #include <tls.h>
 
-#define CLONE_VM      0x00000100
-
 /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
 	     void *parent_tidptr, void *tls, void *child_tidptr) */
 
diff --git a/sysdeps/unix/sysv/linux/mips/clone.S b/sysdeps/unix/sysv/linux/mips/clone.S
index 8b79457b1f..57b6c5e5bb 100644
--- a/sysdeps/unix/sysv/linux/mips/clone.S
+++ b/sysdeps/unix/sysv/linux/mips/clone.S
@@ -25,9 +25,6 @@
 #include <bits/errno.h>
 #include <tls.h>
 
-#define CLONE_VM      0x00000100
-#define CLONE_THREAD  0x00010000
-
 /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
 	     void *parent_tidptr, void *tls, void *child_tidptr) */
 
@@ -137,14 +134,9 @@ L(thread_start):
 	/* Call the user's function.  */
 	jal		t9
 
-	/* Call _exit rather than doing it inline for breakpoint purposes.  */
 	move		a0,v0
-#ifdef __PIC__
-	PTR_LA		t9,_exit
-	jalr		t9
-#else
-	jal		_exit
-#endif
+	li		v0,__NR_exit
+	syscall
 
 	END(__thread_start)
 
diff --git a/sysdeps/unix/sysv/linux/nios2/clone.S b/sysdeps/unix/sysv/linux/nios2/clone.S
index 7929dfa48a..2ba825888c 100644
--- a/sysdeps/unix/sysv/linux/nios2/clone.S
+++ b/sysdeps/unix/sysv/linux/nios2/clone.S
@@ -25,8 +25,6 @@
 #include <bits/errno.h>
 #include <tcb-offsets.h>
 
-#define CLONE_VM      0x00000100
-
 /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
 	     void *parent_tidptr, void *tls, void *child_tidptr) */
 
@@ -75,18 +73,9 @@ thread_start:
         /* Call the user's function.  */
 	callr	r5
 
-	/* _exit with the result.  */
-	mov	r4, r2
-#ifdef PIC
-	nextpc	r22
-1:	movhi	r8, %hiadj(_gp_got - 1b)
-	addi	r8, r8, %lo(_gp_got - 1b)
-	add	r22, r22, r8
-	ldw	r8, %call(HIDDEN_JUMPTARGET(_exit))(r22)
-	jmp	r8
-#else
-	jmpi	_exit
-#endif
+	/* exit with the result.  */
+	movi	r2, SYS_ify (exit)
+	trap
 	cfi_endproc
 
 	cfi_startproc
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S b/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S
index a07b7d3238..e48cc5f2f3 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc32/clone.S
@@ -20,10 +20,6 @@
 #define _ERRNO_H	1
 #include <bits/errno.h>
 
-#define CLONE_VM	0x00000100
-#define CLONE_THREAD	0x00010000
-
-
 /* This is the only really unusual system call in PPC linux, but not
    because of any weirdness in the system call itself; because of
    all the freaky stuff we have to do to make the call useful.  */
@@ -80,8 +76,7 @@ ENTRY (__clone)
 	mtctr	r30
 	mr	r3,r31
 	bctrl
-	/* Call _exit with result from procedure.  */
-	b	HIDDEN_JUMPTARGET(_exit)
+	DO_CALL(SYS_ify(exit))
 
 L(parent):
 	/* Parent.  Restore registers & return.  */
diff --git a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S
index 9e5bfd2d03..78c353a8c7 100644
--- a/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S
+++ b/sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S
@@ -20,9 +20,6 @@
 #define _ERRNO_H	1
 #include <bits/errno.h>
 
-#define CLONE_VM	0x00000100
-#define CLONE_THREAD	0x00010000
-
 /* This is the only really unusual system call in PPC linux, but not
    because of any weirdness in the system call itself; because of
    all the freaky stuff we have to do to make the call useful.  */
@@ -84,15 +81,11 @@ ENTRY (__clone)
 	mr	r3,r31
 	bctrl
 	ld	r2,FRAME_TOC_SAVE(r1)
-	/* Call _exit with result from procedure.  */
-#ifdef SHARED
-	b	JUMPTARGET(__GI__exit)
-#else
-	bl	JUMPTARGET(_exit)
+
+	DO_CALL(SYS_ify(exit))
 	/* We won't ever get here but provide a nop so that the linker
 	   will insert a toc adjusting stub if necessary.  */
 	nop
-#endif
 
 L(badargs):
 	cfi_startproc
diff --git a/sysdeps/unix/sysv/linux/sh/clone.S b/sysdeps/unix/sysv/linux/sh/clone.S
index 9063b21928..b13a64bb10 100644
--- a/sysdeps/unix/sysv/linux/sh/clone.S
+++ b/sysdeps/unix/sysv/linux/sh/clone.S
@@ -73,25 +73,8 @@ ENTRY(__clone)
 	 mov.l	@(4,r15), r4
 
 	/* we are done, passing the return value through r0  */
-	mov.l	.L3, r1
-#ifdef SHARED
-	mov.l	r12, @-r15
-	sts.l	pr, @-r15
-	mov	r0, r4
-	mova	.LG, r0
-	mov.l	.LG, r12
-	add	r0, r12
-	mova	.L3, r0
-	add	r0, r1
-	jsr	@r1
-	 nop
-	lds.l	@r15+, pr
-	rts
-	 mov.l	@r15+, r12
-#else
-	jmp	@r1
-	 mov	r0, r4
-#endif
+	mov	#+SYS_ify(exit), r3
+	trapa	#0x15
 	.align	2
 .LG:
 	.long	_GLOBAL_OFFSET_TABLE_
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S
index 6d2f5bd55f..1afa26e559 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S
+++ b/sysdeps/unix/sysv/linux/sparc/sparc32/clone.S
@@ -24,8 +24,6 @@
 #include <tcb-offsets.h>
 #include <sysdep.h>
 
-#define CLONE_VM	0x00000100
-
 /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
 	     pid_t *ptid, void *tls, pid_t *ctid); */
 
@@ -81,7 +79,8 @@ __thread_start:
 	mov	%g0, %fp	/* terminate backtrace */
 	call	%g2
 	 mov	%g3,%o0
-	call	HIDDEN_JUMPTARGET(_exit),0
+	set	__NR_exit, %g1
+	ta	0x10
 	 nop
 
 	.size	__thread_start, .-__thread_start
diff --git a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S
index fc28539a59..785ccd1beb 100644
--- a/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S
+++ b/sysdeps/unix/sysv/linux/sparc/sparc64/clone.S
@@ -24,8 +24,6 @@
 #include <tcb-offsets.h>
 #include <sysdep.h>
 
-#define CLONE_VM	0x00000100
-
 /* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg,
 	     pid_t *ptid, void *tls, pid_t *ctid); */
 
@@ -78,7 +76,8 @@ __thread_start:
 	mov	%g0, %fp	/* terminate backtrace */
 	call	%g2
 	 mov	%g3,%o0
-	call	HIDDEN_JUMPTARGET(_exit),0
+	set	__NR_exit, %g1
+	ta	0x6d
 	 nop
 
 	.size	__thread_start, .-__thread_start
diff --git a/sysdeps/unix/sysv/linux/tile/clone.S b/sysdeps/unix/sysv/linux/tile/clone.S
index d7d2a3b968..9610acdd8d 100644
--- a/sysdeps/unix/sysv/linux/tile/clone.S
+++ b/sysdeps/unix/sysv/linux/tile/clone.S
@@ -168,10 +168,8 @@ ENTRY (__clone)
 	 move r0, r31
 	 jalr r32
 	}
-	{
-	 j HIDDEN_JUMPTARGET(_exit)
-	 info INFO_OP_CANNOT_BACKTRACE   /* Notify backtracer to stop. */
-	}
+	moveli TREG_SYSCALL_NR_NAME, __NR_exit
+	swint1
 PSEUDO_END (__clone)
 
 libc_hidden_def (__clone)
diff --git a/sysdeps/unix/sysv/linux/tst-clone3.c b/sysdeps/unix/sysv/linux/tst-clone3.c
new file mode 100644
index 0000000000..a742237cb3
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/tst-clone3.c
@@ -0,0 +1,96 @@
+/* Check if clone (CLONE_THREAD) does not call exit_group (BZ #21512)
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <string.h>
+#include <sched.h>
+#include <signal.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <linux/futex.h>
+
+#include <stackinfo.h>  /* For _STACK_GROWS_{UP,DOWN}.  */
+#include <support/check.h>
+
+/* Test if clone call with CLONE_THREAD does not call exit_group.  The 'f'
+   function returns '1', which will be used by clone thread to call the
+   'exit' syscall directly.  If _exit is used instead, exit_group will be
+   used and thus the thread group will finish with return value of '1'
+   (where '2' from main thread is expected.  */
+
+static int
+f (void *a)
+{
+  return 1;
+}
+
+/* Futex wait for TID argument, similar to pthread_join internal
+   implementation.  */
+#define wait_tid(tid) \
+  do {					\
+    __typeof (tid) __tid;		\
+    while ((__tid = (tid)) != 0)	\
+      futex_wait (&(tid), __tid);	\
+  } while (0)
+
+static inline int
+futex_wait (int *futexp, int val)
+{
+  return syscall (__NR_futex, futexp, FUTEX_WAIT, val);
+}
+
+static int
+do_test (void)
+{
+  char st[1024] __attribute__ ((aligned));
+  int clone_flags = CLONE_THREAD;
+  /* Minimum required flags to used along with CLONE_THREAD.  */
+  clone_flags |= CLONE_VM | CLONE_SIGHAND;
+  /* We will used ctid to call on futex to wait for thread exit.  */
+  clone_flags |= CLONE_CHILD_CLEARTID;
+  pid_t ctid, tid;
+
+#ifdef __ia64__
+  extern int __clone2 (int (*__fn) (void *__arg), void *__child_stack_base,
+		       size_t __child_stack_size, int __flags,
+		       void *__arg, ...);
+  tid = __clone2 (f, st, sizeof (st), clone_flags, NULL, /* ptid */ NULL,
+		  /* tls */ NULL, &ctid);
+#else
+#if _STACK_GROWS_DOWN
+  tid = clone (f, st + sizeof (st), clone_flags, NULL, /* ptid */ NULL,
+	       /* tls */ NULL, &ctid);
+#elif _STACK_GROWS_UP
+  tid = clone (f, st, clone_flags, NULL, /* ptid */ NULL, /* tls */ NULL,
+	       &ctid);
+#else
+#error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
+#endif
+#endif
+  if (tid == -1)
+    FAIL_EXIT1 ("clone failed: %m");
+
+  ctid = tid;
+  wait_tid (ctid);
+
+  return 2;
+}
+
+#define EXPECTED_STATUS 2
+#include <support/test-driver.c>
diff --git a/sysdeps/unix/sysv/linux/x86_64/clone.S b/sysdeps/unix/sysv/linux/x86_64/clone.S
index d5c2d07885..b10fc2999c 100644
--- a/sysdeps/unix/sysv/linux/x86_64/clone.S
+++ b/sysdeps/unix/sysv/linux/x86_64/clone.S
@@ -23,8 +23,6 @@
 #include <bits/errno.h>
 #include <asm-syntax.h>
 
-#define CLONE_VM	0x00000100
-
 /* The userland implementation is:
    int clone (int (*fn)(void *arg), void *child_stack, int flags, void *arg),
    the kernel entry is:
@@ -97,7 +95,8 @@ L(thread_start):
 	call	*%rax
 	/* Call exit with return value from function call. */
 	movq	%rax, %rdi
-	call	HIDDEN_JUMPTARGET (_exit)
+	movl	$SYS_ify(exit), %eax
+	syscall
 	cfi_endproc;
 
 	cfi_startproc;