glibc/0009_nptl_2.17_adapt_for_bug_29029.patch

249 lines
8.4 KiB
Diff

From ffdf4f3f121f35834131396c52049745cca21a22 Mon Sep 17 00:00:00 2001
From: Yang Yanchao <yangyanchao6@huawei.com>
Date: Mon, 18 Apr 2022 11:10:46 +0800
Subject: [PATCH] nptl 2.17 adapt for bug 29029
upstream bug 29029 has revert some struct and function,
this commit is to adapt the change.
---
nptl_2_17/cancellation.c | 91 +++++++++++++++++++++++++++++++++
nptl_2_17/cancellation_2_17.c | 60 ++++++++++++++++------
nptl_2_17/compat_pthread_2_17.h | 21 --------
3 files changed, 136 insertions(+), 36 deletions(-)
create mode 100644 nptl_2_17/cancellation.c
diff --git a/nptl_2_17/cancellation.c b/nptl_2_17/cancellation.c
new file mode 100644
index 00000000..f4b08902
--- /dev/null
+++ b/nptl_2_17/cancellation.c
@@ -0,0 +1,91 @@
+/* Copyright (C) 2002-2022 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
+ <https://www.gnu.org/licenses/>. */
+
+#include <setjmp.h>
+#include <stdlib.h>
+#include "pthreadP.h"
+#include <futex-internal.h>
+
+
+/* The next two functions are similar to pthread_setcanceltype() but
+ more specialized for the use in the cancelable functions like write().
+ They do not need to check parameters etc. These functions must be
+ AS-safe, with the exception of the actual cancellation, because they
+ are called by wrappers around AS-safe functions like write().*/
+int
+__pthread_enable_asynccancel (void)
+{
+ struct pthread *self = THREAD_SELF;
+ int oldval = atomic_load_relaxed (&self->cancelhandling);
+
+ while (1)
+ {
+ int newval = oldval | CANCELTYPE_BITMASK;
+
+ if (newval == oldval)
+ break;
+
+ if (atomic_compare_exchange_weak_acquire (&self->cancelhandling,
+ &oldval, newval))
+ {
+ if (cancel_enabled_and_canceled_and_async (newval))
+ {
+ self->result = PTHREAD_CANCELED;
+ __do_cancel ();
+ }
+
+ break;
+ }
+ }
+
+ return oldval;
+}
+libc_hidden_def (__pthread_enable_asynccancel)
+
+/* See the comment for __pthread_enable_asynccancel regarding
+ the AS-safety of this function. */
+void
+__pthread_disable_asynccancel (int oldtype)
+{
+ /* If asynchronous cancellation was enabled before we do not have
+ anything to do. */
+ if (oldtype & CANCELTYPE_BITMASK)
+ return;
+
+ struct pthread *self = THREAD_SELF;
+ int newval;
+ int oldval = atomic_load_relaxed (&self->cancelhandling);
+ do
+ {
+ newval = oldval & ~CANCELTYPE_BITMASK;
+ }
+ while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling,
+ &oldval, newval));
+
+ /* We cannot return when we are being canceled. Upon return the
+ thread might be things which would have to be undone. The
+ following loop should loop until the cancellation signal is
+ delivered. */
+ while (__glibc_unlikely ((newval & (CANCELING_BITMASK | CANCELED_BITMASK))
+ == CANCELING_BITMASK))
+ {
+ futex_wait_simple ((unsigned int *) &self->cancelhandling, newval,
+ FUTEX_PRIVATE);
+ newval = atomic_load_relaxed (&self->cancelhandling);
+ }
+}
+libc_hidden_def (__pthread_disable_asynccancel)
diff --git a/nptl_2_17/cancellation_2_17.c b/nptl_2_17/cancellation_2_17.c
index 5c9ce572..9bc199e7 100644
--- a/nptl_2_17/cancellation_2_17.c
+++ b/nptl_2_17/cancellation_2_17.c
@@ -1,6 +1,5 @@
-/* Copyright (C) 2002-2018 Free Software Foundation, Inc.
+/* Copyright (C) 2002-2022 Free Software Foundation, Inc.
This file is part of the GNU C Library.
- Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
@@ -14,30 +13,42 @@
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/>. */
+ <https://www.gnu.org/licenses/>. */
#include "pthreadP_2_17.h"
#include <setjmp.h>
#include <stdlib.h>
#include <futex-internal.h>
+/* The next two functions are similar to pthread_setcanceltype() but
+ more specialized for the use in the cancelable functions like write().
+ They do not need to check parameters etc. These functions must be
+ AS-safe, with the exception of the actual cancellation, because they
+ are called by wrappers around AS-safe functions like write().*/
int
__pthread_enable_asynccancel (void)
{
struct pthread *self = THREAD_SELF;
+ int oldval = atomic_load_relaxed (&self->cancelhandling);
- int oldval = THREAD_GETMEM (self, canceltype);
- THREAD_SETMEM (self, canceltype, PTHREAD_CANCEL_ASYNCHRONOUS);
+ while (1)
+ {
+ int newval = oldval | CANCELTYPE_BITMASK;
- int ch = THREAD_GETMEM (self, cancelhandling);
+ if (newval == oldval)
+ break;
- if (self->cancelstate == PTHREAD_CANCEL_ENABLE
- && (ch & CANCELED_BITMASK)
- && !(ch & EXITING_BITMASK)
- && !(ch & TERMINATED_BITMASK))
- {
- THREAD_SETMEM (self, result, PTHREAD_CANCELED);
- __do_cancel ();
+ if (atomic_compare_exchange_weak_acquire (&self->cancelhandling,
+ &oldval, newval))
+ {
+ if (cancel_enabled_and_canceled_and_async (newval))
+ {
+ self->result = PTHREAD_CANCELED;
+ __do_cancel ();
+ }
+
+ break;
+ }
}
return oldval;
@@ -51,10 +62,29 @@ __pthread_disable_asynccancel (int oldtype)
{
/* If asynchronous cancellation was enabled before we do not have
anything to do. */
- if (oldtype == PTHREAD_CANCEL_ASYNCHRONOUS)
+ if (oldtype & CANCELTYPE_BITMASK)
return;
struct pthread *self = THREAD_SELF;
- self->canceltype = PTHREAD_CANCEL_DEFERRED;
+ int newval;
+ int oldval = atomic_load_relaxed (&self->cancelhandling);
+ do
+ {
+ newval = oldval & ~CANCELTYPE_BITMASK;
+ }
+ while (!atomic_compare_exchange_weak_acquire (&self->cancelhandling,
+ &oldval, newval));
+
+ /* We cannot return when we are being canceled. Upon return the
+ thread might be things which would have to be undone. The
+ following loop should loop until the cancellation signal is
+ delivered. */
+ while (__glibc_unlikely ((newval & (CANCELING_BITMASK | CANCELED_BITMASK))
+ == CANCELING_BITMASK))
+ {
+ futex_wait_simple ((unsigned int *) &self->cancelhandling, newval,
+ FUTEX_PRIVATE);
+ newval = atomic_load_relaxed (&self->cancelhandling);
+ }
}
libc_hidden_def (__pthread_disable_asynccancel)
diff --git a/nptl_2_17/compat_pthread_2_17.h b/nptl_2_17/compat_pthread_2_17.h
index d13051ba..5109ebc3 100644
--- a/nptl_2_17/compat_pthread_2_17.h
+++ b/nptl_2_17/compat_pthread_2_17.h
@@ -19,30 +19,9 @@
#define __PTHREAD_MUTEX_USE_UNION 0
#endif
-#define CANCELSTATE_BIT 0
-#define CANCELSTATE_BITMASK (0x01 << CANCELSTATE_BIT)
- /* Bit set if asynchronous cancellation mode is selected. */
-#define CANCELTYPE_BIT 1
-#define CANCELTYPE_BITMASK (0x01 << CANCELTYPE_BIT)
- /* Bit set if canceling has been initiated. */
-#define CANCELING_BIT 2
-#define CANCELING_BITMASK (0x01 << CANCELING_BIT)
- /* Bit set if canceled. */
-#define CANCELED_BIT 3
-#define CANCELED_BITMASK (0x01 << CANCELED_BIT)
- /* Bit set if thread is exiting. */
-#define EXITING_BIT 4
-#define EXITING_BITMASK (0x01 << EXITING_BIT)
- /* Bit set if thread terminated and TCB is freed. */
-#define TERMINATED_BIT 5
-#define TERMINATED_BITMASK (0x01 << TERMINATED_BIT)
- /* Bit set if thread is supposed to change XID. */
-#define SETXID_BIT 6
-#define SETXID_BITMASK (0x01 << SETXID_BIT)
/* Mask for the rest. Helps the compiler to optimize. */
#define CANCEL_RESTMASK 0xffffff80
-
#define CANCEL_ENABLED_AND_CANCELED_AND_ASYNCHRONOUS(value) \
(((value) & (CANCELSTATE_BITMASK | CANCELTYPE_BITMASK | CANCELED_BITMASK \
| EXITING_BITMASK | CANCEL_RESTMASK | TERMINATED_BITMASK)) \
--
2.33.0