From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755434AbdLGNLU (ORCPT ); Thu, 7 Dec 2017 08:11:20 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:34268 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753914AbdLGNLQ (ORCPT ); Thu, 7 Dec 2017 08:11:16 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Heiko Carstens , Martin Schwidefsky , Ben Hutchings Subject: [PATCH 4.14 04/75] s390/runtime instrumentation: simplify task exit handling Date: Thu, 7 Dec 2017 14:07:26 +0100 Message-Id: <20171207130818.919491737@linuxfoundation.org> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20171207130818.742746317@linuxfoundation.org> References: <20171207130818.742746317@linuxfoundation.org> User-Agent: quilt/0.65 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Heiko Carstens commit 8d9047f8b967ce6181fd824ae922978e1b055cc0 upstream. Free data structures required for runtime instrumentation from arch_release_task_struct(). This allows to simplify the code a bit, and also makes the semantics a bit easier: arch_release_task_struct() is never called from the task that is being removed. In addition this allows to get rid of exit_thread() in a later patch. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- arch/s390/include/asm/runtime_instr.h | 4 +++- arch/s390/kernel/process.c | 5 ++--- arch/s390/kernel/runtime_instr.c | 30 +++++++++++++++--------------- 3 files changed, 20 insertions(+), 19 deletions(-) --- a/arch/s390/include/asm/runtime_instr.h +++ b/arch/s390/include/asm/runtime_instr.h @@ -86,6 +86,8 @@ static inline void restore_ri_cb(struct load_runtime_instr_cb(&runtime_instr_empty_cb); } -void exit_thread_runtime_instr(void); +struct task_struct; + +void runtime_instr_release(struct task_struct *tsk); #endif /* _RUNTIME_INSTR_H */ --- a/arch/s390/kernel/process.c +++ b/arch/s390/kernel/process.c @@ -49,10 +49,8 @@ extern void kernel_thread_starter(void); */ void exit_thread(struct task_struct *tsk) { - if (tsk == current) { - exit_thread_runtime_instr(); + if (tsk == current) exit_thread_gs(); - } } void flush_thread(void) @@ -65,6 +63,7 @@ void release_thread(struct task_struct * void arch_release_task_struct(struct task_struct *tsk) { + runtime_instr_release(tsk); } int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) --- a/arch/s390/kernel/runtime_instr.c +++ b/arch/s390/kernel/runtime_instr.c @@ -21,11 +21,24 @@ /* empty control block to disable RI by loading it */ struct runtime_instr_cb runtime_instr_empty_cb; +void runtime_instr_release(struct task_struct *tsk) +{ + kfree(tsk->thread.ri_cb); +} + static void disable_runtime_instr(void) { - struct pt_regs *regs = task_pt_regs(current); + struct task_struct *task = current; + struct pt_regs *regs; + if (!task->thread.ri_cb) + return; + regs = task_pt_regs(task); + preempt_disable(); load_runtime_instr_cb(&runtime_instr_empty_cb); + kfree(task->thread.ri_cb); + task->thread.ri_cb = NULL; + preempt_enable(); /* * Make sure the RI bit is deleted from the PSW. If the user did not @@ -46,19 +59,6 @@ static void init_runtime_instr_cb(struct cb->valid = 1; } -void exit_thread_runtime_instr(void) -{ - struct task_struct *task = current; - - preempt_disable(); - if (!task->thread.ri_cb) - return; - disable_runtime_instr(); - kfree(task->thread.ri_cb); - task->thread.ri_cb = NULL; - preempt_enable(); -} - SYSCALL_DEFINE1(s390_runtime_instr, int, command) { struct runtime_instr_cb *cb; @@ -67,7 +67,7 @@ SYSCALL_DEFINE1(s390_runtime_instr, int, return -EOPNOTSUPP; if (command == S390_RUNTIME_INSTR_STOP) { - exit_thread_runtime_instr(); + disable_runtime_instr(); return 0; }