From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
To: libc-alpha@sourceware.org
Subject: [PATCH v2 07/21] nptl: powerpc: Fix Race conditions in pthread cancellation (BZ#12683)
Date: Mon, 26 Feb 2018 18:03:22 -0300 [thread overview]
Message-ID: <1519679016-12241-8-git-send-email-adhemerval.zanella@linaro.org> (raw)
In-Reply-To: <1519679016-12241-1-git-send-email-adhemerval.zanella@linaro.org>
This patches adds the powerpc64 modification required for the BZ#12683.
It basically adds the required __pthread_get_pc function and a arch
specific syscall_cancel implementation.
The powerpc requires an arch-specific syscall_cancel because
INTERNAL_SYSCALL_NCS adds a mfcr just after the sc instruction to get
the CR0.SO bit information from kernel (which signals the error
return status). So for cancelled syscalls with side effects,
__pthread_get_pc will point to mcfr and thus invalidating the checks
on sigcancel_handler.
Checked on powerpc64le-linux-gnu and powerpc-linux-gnu.
[BZ #12683]
* sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S: New file.
* sysdeps/unix/sysv/linux/powerpc/sysdep-cancel.h
(__pthread_get_pc): New function.
---
ChangeLog | 5 ++
sysdeps/unix/sysv/linux/powerpc/sigcontextinfo.h | 16 ++++++
sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S | 64 ++++++++++++++++++++++++
3 files changed, 85 insertions(+)
create mode 100644 sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S
diff --git a/sysdeps/unix/sysv/linux/powerpc/sigcontextinfo.h b/sysdeps/unix/sysv/linux/powerpc/sigcontextinfo.h
index 72381e3..3be71f7 100644
--- a/sysdeps/unix/sysv/linux/powerpc/sigcontextinfo.h
+++ b/sysdeps/unix/sysv/linux/powerpc/sigcontextinfo.h
@@ -15,7 +15,11 @@
License along with the GNU C Library; if not, see
<http://www.gnu.org/licenses/>. */
+#ifndef _SIGCONTEXTINFO_H
+#define _SIGCONTEXTINFO_H
+
#include <signal.h>
+#include <stdint.h>
#define SIGCONTEXT struct sigcontext *
#define SIGCONTEXT_EXTRA_ARGS
@@ -24,3 +28,15 @@
#define GET_STACK(ctx) ((void *)((ctx)->regs->gpr[1]))
#define CALL_SIGHANDLER(handler, signo, ctx) \
(handler)((signo), SIGCONTEXT_EXTRA_ARGS (ctx))
+
+static inline uintptr_t
+ucontext_get_pc (const ucontext_t *uc)
+{
+#ifdef __powerpc64__
+ return uc->uc_mcontext.gp_regs[PT_NIP];
+#else
+ return uc->uc_mcontext.uc_regs->gregs[PT_NIP];
+#endif
+}
+
+#endif /* _SIGCONTEXTINFO_H */
diff --git a/sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S b/sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S
new file mode 100644
index 0000000..2e56c72
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/powerpc/syscall_cancel.S
@@ -0,0 +1,64 @@
+/* Cancellable syscall wrapper. Linux/powerpc version.
+ 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 <sysdep.h>
+
+/* long int [r3] __syscall_cancel_arch (int *cancelhandling [r3],
+ long int nr [r4],
+ long int arg1 [r5],
+ long int arg2 [r6],
+ long int arg3 [r7],
+ long int arg4 [r8],
+ long int arg5 [r9],
+ long int arg6 [r10]) */
+
+ENTRY (__syscall_cancel_arch)
+
+ .globl __syscall_cancel_arch_start
+ .type __syscall_cancel_arch_start,@function
+__syscall_cancel_arch_start:
+
+ /* if (*cancelhandling & CANCELED_BITMASK)
+ __syscall_do_cancel() */
+ lwz r0,0(r3)
+ rldicl. r0,r0,62,63
+ beq 1f
+ b __syscall_do_cancel
+ nop
+1:
+ ABORT_TRANSACTION
+ /* Issue a 6 argument syscall, the nr [r4] being the syscall
+ number. */
+ mr r0,r4
+ mr r3,r5
+ mr r4,r6
+ mr r5,r7
+ mr r6,r8
+ mr r7,r9
+ mr r8,r10
+ sc
+
+ .globl __syscall_cancel_arch_end
+ .type __syscall_cancel_arch_end,@function
+__syscall_cancel_arch_end:
+
+ bnslr+
+ neg r3,r3
+ blr
+END (__syscall_cancel_arch)
+libc_hidden_def (__syscall_cancel_arch)
--
2.7.4
next prev parent reply other threads:[~2018-02-26 21:02 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-26 21:03 [PATCH v2 00/21] nptl: Fix Race conditions in pthread cancellation (BZ#12683) Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 01/21] powerpc: Create stackframe information on syscall Adhemerval Zanella
2018-02-26 21:41 ` Andreas Schwab
2018-02-27 12:05 ` Adhemerval Zanella
2018-05-07 2:49 ` Zack Weinberg
2018-05-07 13:57 ` Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 02/21] nptl: Fix testcases for new pthread cancellation mechanism Adhemerval Zanella
2018-02-26 21:43 ` Andreas Schwab
2018-02-27 12:05 ` Adhemerval Zanella
2018-05-07 2:49 ` Zack Weinberg
2018-05-07 17:13 ` Adhemerval Zanella
2018-05-08 13:35 ` Zack Weinberg
2018-05-08 17:26 ` Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 03/21] nptl: Fix Race conditions in pthread cancellation (BZ#12683) Adhemerval Zanella
2018-04-27 12:20 ` Zack Weinberg
2018-04-27 12:25 ` Adhemerval Zanella
2018-05-07 2:48 ` Zack Weinberg
2018-05-07 2:49 ` Zack Weinberg
2018-05-08 17:11 ` Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 04/21] nptl: x86_64: " Adhemerval Zanella
2018-05-07 2:49 ` Zack Weinberg
2018-05-08 17:55 ` Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 05/21] nptl: x32: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 06/21] nptl: i386: " Adhemerval Zanella
2018-05-07 2:49 ` Zack Weinberg
2018-05-08 17:56 ` Adhemerval Zanella
2018-02-26 21:03 ` Adhemerval Zanella [this message]
2018-05-07 19:25 ` [PATCH v2 07/21] nptl: powerpc: " Tulio Magno Quites Machado Filho
2018-05-08 18:07 ` Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 08/21] nptl: aarch64: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 09/21] nptl: arm: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 10/21] nptl: s390: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 11/21] nptl: ia64: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 12/21] nptl: alpha: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 13/21] nptl: m68k: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 14/21] nptl: microblaze: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 15/21] nptl: tile: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 16/21] nptl: sparc: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 17/21] nptl: nios2: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 18/21] nptl: sh: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 19/21] nptl: mips: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 20/21] nptl: hppa: " Adhemerval Zanella
2018-02-26 21:03 ` [PATCH v2 21/21] nptl: riscv: " Adhemerval Zanella
2018-02-27 1:16 ` DJ Delorie
2018-02-27 13:03 ` Adhemerval Zanella
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