[glibc/azanella/bz12683] nptl: hppa: Fix Race conditions in pthread cancellation (BZ#12683)

[Adhemerval Zanella <azanella@sourceware.org>]

https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=114faca7e80b18db150ffaf0642031b5178b5743

commit 114faca7e80b18db150ffaf0642031b5178b5743
Author: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date:   Fri Feb 3 21:07:07 2017 -0200

    nptl: hppa: Fix Race conditions in pthread cancellation (BZ#12683)
    
    This patch adds the hppa modifications required for the BZ#12683 fix
    by adding the arch-specific cancellation syscall bridge.
    
    Checked on hppa-linux-gnu.

Diff:
---
 sysdeps/hppa/nptl/tcb-offsets.sym             |  3 +
 sysdeps/unix/sysv/linux/hppa/syscall_cancel.S | 83 +++++++++++++++++++++++++++
 sysdeps/unix/sysv/linux/hppa/sysdep.h         |  1 +
 3 files changed, 87 insertions(+)

diff --git a/sysdeps/hppa/nptl/tcb-offsets.sym b/sysdeps/hppa/nptl/tcb-offsets.sym
index 6e852f3..0aff5f3 100644
--- a/sysdeps/hppa/nptl/tcb-offsets.sym
+++ b/sysdeps/hppa/nptl/tcb-offsets.sym
@@ -15,3 +15,6 @@ MUTEX_FUTEX		offsetof (pthread_mutex_t, __data.__lock)
 #define thread_offsetof(mem)    (unsigned int)(offsetof(struct pthread, mem) - sizeof(struct pthread))
 TID_THREAD_OFFSET		thread_offsetof (tid)
 MULTIPLE_THREADS_THREAD_OFFSET	thread_offsetof (header.multiple_threads)
+
+-- Not strictly offsets, used on syscall_cancel.S
+TCB_CANCELED_BIT	CANCELED_BIT
diff --git a/sysdeps/unix/sysv/linux/hppa/syscall_cancel.S b/sysdeps/unix/sysv/linux/hppa/syscall_cancel.S
new file mode 100644
index 0000000..caa9ae2
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/hppa/syscall_cancel.S
@@ -0,0 +1,83 @@
+/* Cancellable syscall wrapper.  Linux/hppa version.
+   Copyright (C) 2019 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 <sysdep.h>
+
+/* long int __syscall_cancel_arch (int *cancelhandling,
+				   long int nr,
+				   long int arg1,
+				   long int arg2,
+				   long int arg3,
+				   long int arg4,
+				   long int arg5,
+				   long int arg6)  */
+
+	.text
+ENTRY(__syscall_cancel_arch)
+	stw	%r2,-20(%r30)
+	ldo	128(%r30),%r30
+	cfi_def_cfa_offset (-128)
+	cfi_offset (2, -20)
+	ldw	-180(%r30),%r28
+	copy	%r24,%r31
+	stw	%r28,-104(%r30)
+#ifndef __PIC__
+	cfi_offset (4, 28)
+#endif
+	ldw	-184(%r30),%r28
+	stw	%r28,-108(%r30)
+	ldw	-188(%r30),%r28
+	stw	%r28,-112(%r30)
+	ldw	-192(%r30),%r28
+	stw	%r4,-100(%r30)
+	stw	%r28,-116(%r30)
+	copy	%r25,%r28
+	copy	%r23,%r25
+#ifdef __PIC__
+	stw	%r19,-32(%r30)
+	cfi_offset (4, 28)
+#endif
+
+	.global __syscall_cancel_arch_start
+__syscall_cancel_arch_start:
+
+	ldw	0(%r26),%r20
+	bb,<	%r20,31-TCB_CANCELED_BIT,1f
+	ldw	-120(%r30),%r21
+	ldw	-116(%r30),%r22
+	copy	%r31,%r26
+	ldw	-112(%r30),%r23
+	ldw	-108(%r30),%r24
+	copy	%r19, %r4
+	ble	0x100(%sr2, %r0)
+
+	.global __syscall_cancel_arch_end
+__syscall_cancel_arch_end:
+
+	copy	%r28, %r20
+	copy	%r4, %r19
+	ldw	-148(%r30),%r2
+	ldw	-100(%r30),%r4
+	bv	%r0(%r2)
+	ldo	-128(%r30),%r30
+1:
+	bl	__syscall_do_cancel,%r2
+	nop
+	nop
+END(__syscall_cancel_arch)
+libc_hidden_def (__syscall_cancel_arch)
diff --git a/sysdeps/unix/sysv/linux/hppa/sysdep.h b/sysdeps/unix/sysv/linux/hppa/sysdep.h
index 2eb7377..b2e90e7 100644
--- a/sysdeps/unix/sysv/linux/hppa/sysdep.h
+++ b/sysdeps/unix/sysv/linux/hppa/sysdep.h
@@ -24,6 +24,7 @@
 #include <sysdeps/unix/sysdep.h>
 #include <sysdeps/unix/sysv/linux/sysdep.h>
 #include <sysdeps/hppa/sysdep.h>
+#include <tls.h>
 
 /* Defines RTLD_PRIVATE_ERRNO.  */
 #include <dl-sysdep.h>