From patchwork Thu May 5 18:26:36 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Eric W. Biederman" X-Patchwork-Id: 570182 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A055C433F5 for ; Thu, 5 May 2022 18:34:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1383368AbiEESh4 (ORCPT ); Thu, 5 May 2022 14:37:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38122 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1376753AbiEEShG (ORCPT ); Thu, 5 May 2022 14:37:06 -0400 Received: from out02.mta.xmission.com (out02.mta.xmission.com [166.70.13.232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E16F75DBFA; Thu, 5 May 2022 11:27:20 -0700 (PDT) Received: from in01.mta.xmission.com ([166.70.13.51]:53346) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nmgC7-007BrK-Rg; Thu, 05 May 2022 12:27:19 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:37118 helo=localhost.localdomain) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nmgC6-002BtP-LD; Thu, 05 May 2022 12:27:19 -0600 From: "Eric W. Biederman" To: linux-kernel@vger.kernel.org Cc: rjw@rjwysocki.net, Oleg Nesterov , mingo@kernel.org, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, mgorman@suse.de, bigeasy@linutronix.de, Will Deacon , tj@kernel.org, linux-pm@vger.kernel.org, Peter Zijlstra , Richard Weinberger , Anton Ivanov , Johannes Berg , linux-um@lists.infradead.org, Chris Zankel , Max Filippov , linux-xtensa@linux-xtensa.org, Kees Cook , Jann Horn , linux-ia64@vger.kernel.org, "Eric W. Biederman" , stable@vger.kernel.org Date: Thu, 5 May 2022 13:26:36 -0500 Message-Id: <20220505182645.497868-3-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87a6bv6dl6.fsf_-_@email.froward.int.ebiederm.org> References: <87a6bv6dl6.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nmgC6-002BtP-LD; ; ; mid=<20220505182645.497868-3-ebiederm@xmission.com>; ; ; hst=in01.mta.xmission.com; ; ; ip=68.227.174.4; ; ; frm=ebiederm@xmission.com; ; ; spf=softfail X-XM-AID: U2FsdGVkX1+NY/+R9b/DDPjmitNF/LecD2BgPTMG9GU= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v4 03/12] ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org User mode linux is the last user of the PT_DTRACE flag. Using the flag to indicate single stepping is a little confusing and worse changing tsk->ptrace without locking could potentionally cause problems. So use a thread info flag with a better name instead of flag in tsk->ptrace. Remove the definition PT_DTRACE as uml is the last user. Cc: stable@vger.kernel.org Acked-by: Johannes Berg Signed-off-by: "Eric W. Biederman" --- arch/um/include/asm/thread_info.h | 2 ++ arch/um/kernel/exec.c | 2 +- arch/um/kernel/process.c | 2 +- arch/um/kernel/ptrace.c | 8 ++++---- arch/um/kernel/signal.c | 4 ++-- include/linux/ptrace.h | 1 - 6 files changed, 10 insertions(+), 9 deletions(-) diff --git a/arch/um/include/asm/thread_info.h b/arch/um/include/asm/thread_info.h index 1395cbd7e340..c7b4b49826a2 100644 --- a/arch/um/include/asm/thread_info.h +++ b/arch/um/include/asm/thread_info.h @@ -60,6 +60,7 @@ static inline struct thread_info *current_thread_info(void) #define TIF_RESTORE_SIGMASK 7 #define TIF_NOTIFY_RESUME 8 #define TIF_SECCOMP 9 /* secure computing */ +#define TIF_SINGLESTEP 10 /* single stepping userspace */ #define _TIF_SYSCALL_TRACE (1 << TIF_SYSCALL_TRACE) #define _TIF_SIGPENDING (1 << TIF_SIGPENDING) @@ -68,5 +69,6 @@ static inline struct thread_info *current_thread_info(void) #define _TIF_MEMDIE (1 << TIF_MEMDIE) #define _TIF_SYSCALL_AUDIT (1 << TIF_SYSCALL_AUDIT) #define _TIF_SECCOMP (1 << TIF_SECCOMP) +#define _TIF_SINGLESTEP (1 << TIF_SINGLESTEP) #endif diff --git a/arch/um/kernel/exec.c b/arch/um/kernel/exec.c index c85e40c72779..58938d75871a 100644 --- a/arch/um/kernel/exec.c +++ b/arch/um/kernel/exec.c @@ -43,7 +43,7 @@ void start_thread(struct pt_regs *regs, unsigned long eip, unsigned long esp) { PT_REGS_IP(regs) = eip; PT_REGS_SP(regs) = esp; - current->ptrace &= ~PT_DTRACE; + clear_thread_flag(TIF_SINGLESTEP); #ifdef SUBARCH_EXECVE1 SUBARCH_EXECVE1(regs->regs); #endif diff --git a/arch/um/kernel/process.c b/arch/um/kernel/process.c index 80504680be08..88c5c7844281 100644 --- a/arch/um/kernel/process.c +++ b/arch/um/kernel/process.c @@ -335,7 +335,7 @@ int singlestepping(void * t) { struct task_struct *task = t ? t : current; - if (!(task->ptrace & PT_DTRACE)) + if (!test_thread_flag(TIF_SINGLESTEP)) return 0; if (task->thread.singlestep_syscall) diff --git a/arch/um/kernel/ptrace.c b/arch/um/kernel/ptrace.c index bfaf6ab1ac03..5154b27de580 100644 --- a/arch/um/kernel/ptrace.c +++ b/arch/um/kernel/ptrace.c @@ -11,7 +11,7 @@ void user_enable_single_step(struct task_struct *child) { - child->ptrace |= PT_DTRACE; + set_tsk_thread_flag(child, TIF_SINGLESTEP); child->thread.singlestep_syscall = 0; #ifdef SUBARCH_SET_SINGLESTEPPING @@ -21,7 +21,7 @@ void user_enable_single_step(struct task_struct *child) void user_disable_single_step(struct task_struct *child) { - child->ptrace &= ~PT_DTRACE; + clear_tsk_thread_flag(child, TIF_SINGLESTEP); child->thread.singlestep_syscall = 0; #ifdef SUBARCH_SET_SINGLESTEPPING @@ -120,7 +120,7 @@ static void send_sigtrap(struct uml_pt_regs *regs, int error_code) } /* - * XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and + * XXX Check TIF_SINGLESTEP for singlestepping check and * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check */ int syscall_trace_enter(struct pt_regs *regs) @@ -144,7 +144,7 @@ void syscall_trace_leave(struct pt_regs *regs) audit_syscall_exit(regs); /* Fake a debug trap */ - if (ptraced & PT_DTRACE) + if (test_thread_flag(TIF_SINGLESTEP)) send_sigtrap(®s->regs, 0); if (!test_thread_flag(TIF_SYSCALL_TRACE)) diff --git a/arch/um/kernel/signal.c b/arch/um/kernel/signal.c index 88cd9b5c1b74..ae4658f576ab 100644 --- a/arch/um/kernel/signal.c +++ b/arch/um/kernel/signal.c @@ -53,7 +53,7 @@ static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) unsigned long sp; int err; - if ((current->ptrace & PT_DTRACE) && (current->ptrace & PT_PTRACED)) + if (test_thread_flag(TIF_SINGLESTEP) && (current->ptrace & PT_PTRACED)) singlestep = 1; /* Did we come from a system call? */ @@ -128,7 +128,7 @@ void do_signal(struct pt_regs *regs) * on the host. The tracing thread will check this flag and * PTRACE_SYSCALL if necessary. */ - if (current->ptrace & PT_DTRACE) + if (test_thread_flag(TIF_SINGLESTEP)) current->thread.singlestep_syscall = is_syscall(PT_REGS_IP(¤t->thread.regs)); diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 15b3d176b6b4..4c06f9f8ef3f 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -30,7 +30,6 @@ extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ #define PT_PTRACED 0x00000001 -#define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ #define PT_OPT_FLAG_SHIFT 3 /* PT_TRACE_* event enable flags */