From patchwork Fri Apr 29 21:48:26 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: 12832891 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 C4AB0C433F5 for ; Fri, 29 Apr 2022 21:48:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239396AbiD2VwR (ORCPT ); Fri, 29 Apr 2022 17:52:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47384 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238812AbiD2VwQ (ORCPT ); Fri, 29 Apr 2022 17:52:16 -0400 Received: from out01.mta.xmission.com (out01.mta.xmission.com [166.70.13.231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 403B7DB2D3; Fri, 29 Apr 2022 14:48:57 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:49628) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYTv-007O8s-O2; Fri, 29 Apr 2022 15:48:55 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYTt-007RIp-EJ; Fri, 29 Apr 2022 15:48:55 -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" Date: Fri, 29 Apr 2022 16:48:26 -0500 Message-Id: <20220429214837.386518-1-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYTt-007RIp-EJ;;;mid=<20220429214837.386518-1-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX18QHwhDIVhRddYvW2NsQFv/0UjlGxd6VNQ= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 01/12] signal: Rename send_signal send_signal_locked X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Rename send_signal send_signal_locked and make to make it usable outside of signal.c. Signed-off-by: "Eric W. Biederman" --- include/linux/signal.h | 2 ++ kernel/signal.c | 24 ++++++++++++------------ 2 files changed, 14 insertions(+), 12 deletions(-) diff --git a/include/linux/signal.h b/include/linux/signal.h index a6db6f2ae113..55605bdf5ce9 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -283,6 +283,8 @@ extern int do_send_sig_info(int sig, struct kernel_siginfo *info, extern int group_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p, enum pid_type type); extern int __group_send_sig_info(int, struct kernel_siginfo *, struct task_struct *); +extern int send_signal_locked(int sig, struct kernel_siginfo *info, + struct task_struct *p, enum pid_type type); extern int sigprocmask(int, sigset_t *, sigset_t *); extern void set_current_blocked(sigset_t *); extern void __set_current_blocked(const sigset_t *); diff --git a/kernel/signal.c b/kernel/signal.c index 30cd1ca43bcd..b0403197b0ad 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1071,8 +1071,8 @@ static inline bool legacy_queue(struct sigpending *signals, int sig) return (sig < SIGRTMIN) && sigismember(&signals->signal, sig); } -static int __send_signal(int sig, struct kernel_siginfo *info, struct task_struct *t, - enum pid_type type, bool force) +static int __send_signal_locked(int sig, struct kernel_siginfo *info, + struct task_struct *t, enum pid_type type, bool force) { struct sigpending *pending; struct sigqueue *q; @@ -1212,8 +1212,8 @@ static inline bool has_si_pid_and_uid(struct kernel_siginfo *info) return ret; } -static int send_signal(int sig, struct kernel_siginfo *info, struct task_struct *t, - enum pid_type type) +int send_signal_locked(int sig, struct kernel_siginfo *info, + struct task_struct *t, enum pid_type type) { /* Should SIGKILL or SIGSTOP be received by a pid namespace init? */ bool force = false; @@ -1245,7 +1245,7 @@ static int send_signal(int sig, struct kernel_siginfo *info, struct task_struct force = true; } } - return __send_signal(sig, info, t, type, force); + return __send_signal_locked(sig, info, t, type, force); } static void print_fatal_signal(int signr) @@ -1284,7 +1284,7 @@ __setup("print-fatal-signals=", setup_print_fatal_signals); int __group_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p) { - return send_signal(sig, info, p, PIDTYPE_TGID); + return send_signal_locked(sig, info, p, PIDTYPE_TGID); } int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p, @@ -1294,7 +1294,7 @@ int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p int ret = -ESRCH; if (lock_task_sighand(p, &flags)) { - ret = send_signal(sig, info, p, type); + ret = send_signal_locked(sig, info, p, type); unlock_task_sighand(p, &flags); } @@ -1347,7 +1347,7 @@ force_sig_info_to_task(struct kernel_siginfo *info, struct task_struct *t, if (action->sa.sa_handler == SIG_DFL && (!t->ptrace || (handler == HANDLER_EXIT))) t->signal->flags &= ~SIGNAL_UNKILLABLE; - ret = send_signal(sig, info, t, PIDTYPE_PID); + ret = send_signal_locked(sig, info, t, PIDTYPE_PID); spin_unlock_irqrestore(&t->sighand->siglock, flags); return ret; @@ -1567,7 +1567,7 @@ int kill_pid_usb_asyncio(int sig, int errno, sigval_t addr, if (sig) { if (lock_task_sighand(p, &flags)) { - ret = __send_signal(sig, &info, p, PIDTYPE_TGID, false); + ret = __send_signal_locked(sig, &info, p, PIDTYPE_TGID, false); unlock_task_sighand(p, &flags); } else ret = -ESRCH; @@ -2103,7 +2103,7 @@ bool do_notify_parent(struct task_struct *tsk, int sig) * parent's namespaces. */ if (valid_signal(sig) && sig) - __send_signal(sig, &info, tsk->parent, PIDTYPE_TGID, false); + __send_signal_locked(sig, &info, tsk->parent, PIDTYPE_TGID, false); __wake_up_parent(tsk, tsk->parent); spin_unlock_irqrestore(&psig->siglock, flags); @@ -2601,7 +2601,7 @@ static int ptrace_signal(int signr, kernel_siginfo_t *info, enum pid_type type) /* If the (new) signal is now blocked, requeue it. */ if (sigismember(¤t->blocked, signr) || fatal_signal_pending(current)) { - send_signal(signr, info, current, type); + send_signal_locked(signr, info, current, type); signr = 0; } @@ -4793,7 +4793,7 @@ void kdb_send_sig(struct task_struct *t, int sig) "the deadlock.\n"); return; } - ret = send_signal(sig, SEND_SIG_PRIV, t, PIDTYPE_PID); + ret = send_signal_locked(sig, SEND_SIG_PRIV, t, PIDTYPE_PID); spin_unlock(&t->sighand->siglock); if (ret) kdb_printf("Fail to deliver Signal %d to process %d.\n", From patchwork Fri Apr 29 21:48:27 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: 12832892 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 0A5B7C433F5 for ; Fri, 29 Apr 2022 21:49:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239454AbiD2VwU (ORCPT ); Fri, 29 Apr 2022 17:52:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47408 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239437AbiD2VwU (ORCPT ); Fri, 29 Apr 2022 17:52:20 -0400 Received: from out01.mta.xmission.com (out01.mta.xmission.com [166.70.13.231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AFC2CDB2D3; Fri, 29 Apr 2022 14:49:00 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:49682) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYTz-007OAF-Rg; Fri, 29 Apr 2022 15:48:59 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYTx-007RIp-Mh; Fri, 29 Apr 2022 15:48:59 -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" Date: Fri, 29 Apr 2022 16:48:27 -0500 Message-Id: <20220429214837.386518-2-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYTx-007RIp-Mh;;;mid=<20220429214837.386518-2-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX1/PJ1H6e11rGx9G4m7P4zknN4wEw7q7DrY= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 02/12] signal: Replace __group_send_sig_info with send_signal_locked X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The function send_signal_locked does more than __group_send_sig_info so replace it. Signed-off-by: "Eric W. Biederman" --- drivers/tty/tty_jobctrl.c | 4 ++-- include/linux/signal.h | 1 - kernel/signal.c | 8 +------- kernel/time/posix-cpu-timers.c | 6 +++--- 4 files changed, 6 insertions(+), 13 deletions(-) diff --git a/drivers/tty/tty_jobctrl.c b/drivers/tty/tty_jobctrl.c index 80b86a7992b5..0d04287da098 100644 --- a/drivers/tty/tty_jobctrl.c +++ b/drivers/tty/tty_jobctrl.c @@ -215,8 +215,8 @@ int tty_signal_session_leader(struct tty_struct *tty, int exit_session) spin_unlock_irq(&p->sighand->siglock); continue; } - __group_send_sig_info(SIGHUP, SEND_SIG_PRIV, p); - __group_send_sig_info(SIGCONT, SEND_SIG_PRIV, p); + send_signal_locked(SIGHUP, SEND_SIG_PRIV, p, PIDTYPE_TGID); + send_signal_locked(SIGCONT, SEND_SIG_PRIV, p, PIDTYPE_TGID); put_pid(p->signal->tty_old_pgrp); /* A noop */ spin_lock(&tty->ctrl.lock); tty_pgrp = get_pid(tty->ctrl.pgrp); diff --git a/include/linux/signal.h b/include/linux/signal.h index 55605bdf5ce9..3b98e7a28538 100644 --- a/include/linux/signal.h +++ b/include/linux/signal.h @@ -282,7 +282,6 @@ extern int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p, enum pid_type type); extern int group_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p, enum pid_type type); -extern int __group_send_sig_info(int, struct kernel_siginfo *, struct task_struct *); extern int send_signal_locked(int sig, struct kernel_siginfo *info, struct task_struct *p, enum pid_type type); extern int sigprocmask(int, sigset_t *, sigset_t *); diff --git a/kernel/signal.c b/kernel/signal.c index b0403197b0ad..72d96614effc 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -1281,12 +1281,6 @@ static int __init setup_print_fatal_signals(char *str) __setup("print-fatal-signals=", setup_print_fatal_signals); -int -__group_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p) -{ - return send_signal_locked(sig, info, p, PIDTYPE_TGID); -} - int do_send_sig_info(int sig, struct kernel_siginfo *info, struct task_struct *p, enum pid_type type) { @@ -2173,7 +2167,7 @@ static void do_notify_parent_cldstop(struct task_struct *tsk, spin_lock_irqsave(&sighand->siglock, flags); if (sighand->action[SIGCHLD-1].sa.sa_handler != SIG_IGN && !(sighand->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDSTOP)) - __group_send_sig_info(SIGCHLD, &info, parent); + send_signal_locked(SIGCHLD, &info, parent, PIDTYPE_TGID); /* * Even if SIGCHLD is not generated, we must wake up wait4 calls. */ diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c index 0a97193984db..cb925e8ef9a8 100644 --- a/kernel/time/posix-cpu-timers.c +++ b/kernel/time/posix-cpu-timers.c @@ -870,7 +870,7 @@ static inline void check_dl_overrun(struct task_struct *tsk) { if (tsk->dl.dl_overrun) { tsk->dl.dl_overrun = 0; - __group_send_sig_info(SIGXCPU, SEND_SIG_PRIV, tsk); + send_signal_locked(SIGXCPU, SEND_SIG_PRIV, tsk, PIDTYPE_TGID); } } @@ -884,7 +884,7 @@ static bool check_rlimit(u64 time, u64 limit, int signo, bool rt, bool hard) rt ? "RT" : "CPU", hard ? "hard" : "soft", current->comm, task_pid_nr(current)); } - __group_send_sig_info(signo, SEND_SIG_PRIV, current); + send_signal_locked(signo, SEND_SIG_PRIV, current, PIDTYPE_TGID); return true; } @@ -958,7 +958,7 @@ static void check_cpu_itimer(struct task_struct *tsk, struct cpu_itimer *it, trace_itimer_expire(signo == SIGPROF ? ITIMER_PROF : ITIMER_VIRTUAL, task_tgid(tsk), cur_time); - __group_send_sig_info(signo, SEND_SIG_PRIV, tsk); + send_signal_locked(signo, SEND_SIG_PRIV, tsk, PIDTYPE_TGID); } if (it->expires && it->expires < *expires) From patchwork Fri Apr 29 21:48:28 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: 12832941 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 53B9DC433FE for ; Fri, 29 Apr 2022 22:07:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1348757AbiD2WKn (ORCPT ); Fri, 29 Apr 2022 18:10:43 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46300 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234141AbiD2WKn (ORCPT ); Fri, 29 Apr 2022 18:10:43 -0400 X-Greylist: delayed 1164 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Fri, 29 Apr 2022 15:07:23 PDT Received: from out02.mta.xmission.com (out02.mta.xmission.com [166.70.13.232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E9668DBD36; Fri, 29 Apr 2022 15:07:22 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:54628) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYU4-00AIHv-5u; Fri, 29 Apr 2022 15:49:04 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYU1-007RIp-SJ; Fri, 29 Apr 2022 15:49:03 -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: Fri, 29 Apr 2022 16:48:28 -0500 Message-Id: <20220429214837.386518-3-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYU1-007RIp-SJ;;;mid=<20220429214837.386518-3-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX180O+oNrK8kueX5JDUgMLmEvvwqhHxDh38= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 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 in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@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 */ From patchwork Fri Apr 29 21:48:29 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: 12832893 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 8C5F4C433F5 for ; Fri, 29 Apr 2022 21:49:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239437AbiD2Vw2 (ORCPT ); Fri, 29 Apr 2022 17:52:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47468 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239499AbiD2Vw1 (ORCPT ); Fri, 29 Apr 2022 17:52:27 -0400 Received: from out01.mta.xmission.com (out01.mta.xmission.com [166.70.13.231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8878DDB494; Fri, 29 Apr 2022 14:49:08 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:49802) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYU7-007OC4-8V; Fri, 29 Apr 2022 15:49:07 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYU6-007RIp-6O; Fri, 29 Apr 2022 15:49:06 -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: Fri, 29 Apr 2022 16:48:29 -0500 Message-Id: <20220429214837.386518-4-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYU6-007RIp-6O;;;mid=<20220429214837.386518-4-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX1+l1YL71w1w1BKCUUmYDmX3zFUC3cyNA9I= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 04/12] ptrace/xtensa: Replace PT_SINGLESTEP 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 in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org xtensa is the last user of the PT_SINGLESTEP flag. Changing tsk->ptrace in user_enable_single_step and user_disable_single_step without locking could potentiallly cause problems. So use a thread info flag instead of a flag in tsk->ptrace. Use TIF_SINGLESTEP that xtensa already had defined but unused. Remove the definitions of PT_SINGLESTEP and PT_BLOCKSTEP as they have no more users. Cc: stable@vger.kernel.org Acked-by: Max Filippov Signed-off-by: "Eric W. Biederman" --- arch/xtensa/kernel/ptrace.c | 4 ++-- arch/xtensa/kernel/signal.c | 4 ++-- include/linux/ptrace.h | 6 ------ 3 files changed, 4 insertions(+), 10 deletions(-) diff --git a/arch/xtensa/kernel/ptrace.c b/arch/xtensa/kernel/ptrace.c index 323c678a691f..b952e67cc0cc 100644 --- a/arch/xtensa/kernel/ptrace.c +++ b/arch/xtensa/kernel/ptrace.c @@ -225,12 +225,12 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task) void user_enable_single_step(struct task_struct *child) { - child->ptrace |= PT_SINGLESTEP; + set_tsk_thread_flag(child, TIF_SINGLESTEP); } void user_disable_single_step(struct task_struct *child) { - child->ptrace &= ~PT_SINGLESTEP; + clear_tsk_thread_flag(child, TIF_SINGLESTEP); } /* diff --git a/arch/xtensa/kernel/signal.c b/arch/xtensa/kernel/signal.c index 6f68649e86ba..ac50ec46c8f1 100644 --- a/arch/xtensa/kernel/signal.c +++ b/arch/xtensa/kernel/signal.c @@ -473,7 +473,7 @@ static void do_signal(struct pt_regs *regs) /* Set up the stack frame */ ret = setup_frame(&ksig, sigmask_to_save(), regs); signal_setup_done(ret, &ksig, 0); - if (current->ptrace & PT_SINGLESTEP) + if (test_thread_flag(TIF_SINGLESTEP)) task_pt_regs(current)->icountlevel = 1; return; @@ -499,7 +499,7 @@ static void do_signal(struct pt_regs *regs) /* If there's no signal to deliver, we just restore the saved mask. */ restore_saved_sigmask(); - if (current->ptrace & PT_SINGLESTEP) + if (test_thread_flag(TIF_SINGLESTEP)) task_pt_regs(current)->icountlevel = 1; return; } diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 4c06f9f8ef3f..c952c5ba8fab 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -46,12 +46,6 @@ extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, #define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT) #define PT_SUSPEND_SECCOMP (PTRACE_O_SUSPEND_SECCOMP << PT_OPT_FLAG_SHIFT) -/* single stepping state bits (used on ARM and PA-RISC) */ -#define PT_SINGLESTEP_BIT 31 -#define PT_SINGLESTEP (1< X-Patchwork-Id: 12832894 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 019A3C433FE for ; Fri, 29 Apr 2022 21:49:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239528AbiD2Vwa (ORCPT ); Fri, 29 Apr 2022 17:52:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47514 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239541AbiD2Vwa (ORCPT ); Fri, 29 Apr 2022 17:52:30 -0400 Received: from out01.mta.xmission.com (out01.mta.xmission.com [166.70.13.231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 490C5DB4B6; Fri, 29 Apr 2022 14:49:11 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:49840) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUA-007OD7-DD; Fri, 29 Apr 2022 15:49:10 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYU9-007RIp-7i; Fri, 29 Apr 2022 15:49:09 -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" Date: Fri, 29 Apr 2022 16:48:30 -0500 Message-Id: <20220429214837.386518-5-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYU9-007RIp-7i;;;mid=<20220429214837.386518-5-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX1/m1omujSCUx+WoYaAXDnsPr1oSU3IgaAc= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 05/12] signal: Use lockdep_assert_held instead of assert_spin_locked X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The distinction is that assert_spin_locked() checks if the lock is held *by*anyone* whereas lockdep_assert_held() asserts the current context holds the lock. Also, the check goes away if you build without lockdep. Suggested-by: Peter Zijlstra Link: https://lkml.kernel.org/r/Ympr/+PX4XgT/UKU@hirez.programming.kicks-ass.net Signed-off-by: "Eric W. Biederman" --- kernel/signal.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/signal.c b/kernel/signal.c index 72d96614effc..3fd2ce133387 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -884,7 +884,7 @@ static int check_kill_permission(int sig, struct kernel_siginfo *info, static void ptrace_trap_notify(struct task_struct *t) { WARN_ON_ONCE(!(t->ptrace & PT_SEIZED)); - assert_spin_locked(&t->sighand->siglock); + lockdep_assert_held(&t->sighand->siglock); task_set_jobctl_pending(t, JOBCTL_TRAP_NOTIFY); ptrace_signal_wake_up(t, t->jobctl & JOBCTL_LISTENING); @@ -1079,7 +1079,7 @@ static int __send_signal_locked(int sig, struct kernel_siginfo *info, int override_rlimit; int ret = 0, result; - assert_spin_locked(&t->sighand->siglock); + lockdep_assert_held(&t->sighand->siglock); result = TRACE_SIGNAL_IGNORED; if (!prepare_signal(sig, t, force)) From patchwork Fri Apr 29 21:48:31 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: 12832896 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 30A24C433EF for ; Fri, 29 Apr 2022 21:49:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239541AbiD2Vwm (ORCPT ); Fri, 29 Apr 2022 17:52:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47550 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239590AbiD2Vwd (ORCPT ); Fri, 29 Apr 2022 17:52:33 -0400 Received: from out01.mta.xmission.com (out01.mta.xmission.com [166.70.13.231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C817DB4B6; Fri, 29 Apr 2022 14:49:14 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:49872) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUD-007OE5-Gn; Fri, 29 Apr 2022 15:49:13 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUC-007RIp-Gl; Fri, 29 Apr 2022 15:49:13 -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, Al Viro Date: Fri, 29 Apr 2022 16:48:31 -0500 Message-Id: <20220429214837.386518-6-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYUC-007RIp-Gl;;;mid=<20220429214837.386518-6-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX1+vbrOvInw4J3zemlYv0MOslvPzk7U8i+A= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 06/12] ptrace: Reimplement PTRACE_KILL by always sending SIGKILL X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Call send_sig_info in PTRACE_KILL instead of ptrace_resume. Calling ptrace_resume is not safe to call if the task has not been stopped with ptrace_freeze_traced. Cc: stable@vger.kernel.org Reported-by: Al Viro Suggested-by: Al Viro Signed-off-by: "Eric W. Biederman" --- kernel/ptrace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index ccc4b465775b..43da5764b6f3 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -1238,7 +1238,7 @@ int ptrace_request(struct task_struct *child, long request, case PTRACE_KILL: if (child->exit_state) /* already dead */ return 0; - return ptrace_resume(child, request, SIGKILL); + return send_sig_info(SIGKILL, SEND_SIG_NOINFO, child); #ifdef CONFIG_HAVE_ARCH_TRACEHOOK case PTRACE_GETREGSET: From patchwork Fri Apr 29 21:48:32 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: 12832945 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 3568AC433FE for ; Fri, 29 Apr 2022 22:07:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381276AbiD2WLC (ORCPT ); Fri, 29 Apr 2022 18:11:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47528 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1381167AbiD2WK7 (ORCPT ); Fri, 29 Apr 2022 18:10:59 -0400 Received: from out02.mta.xmission.com (out02.mta.xmission.com [166.70.13.232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4AA23DC9A2; Fri, 29 Apr 2022 15:07:29 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:54790) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUG-00AIJQ-Lr; Fri, 29 Apr 2022 15:49:16 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUF-007RIp-GC; Fri, 29 Apr 2022 15:49:16 -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" Date: Fri, 29 Apr 2022 16:48:32 -0500 Message-Id: <20220429214837.386518-7-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYUF-007RIp-GC;;;mid=<20220429214837.386518-7-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX1+Z8HlV3UkGfoy7F/rNg/M1zhIgnTw75z0= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 07/12] ptrace: Don't change __state X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Stop playing with tsk->__state to remove TASK_WAKEKILL while a ptrace command is executing. Instead TASK_WAKEKILL from the definition of TASK_TRACED, and implemention a new jobctl flag TASK_PTRACE_FROZEN. This new This new flag is set in jobctl_freeze_task and cleared when ptrace_stop is awoken or in jobctl_unfreeze_task (when ptrace_stop remains asleep). In singal_wake_up add __TASK_TRACED to state along with TASK_WAKEKILL when it is indicated a fatal signal is pending. Skip adding __TASK_TRACED when TASK_PTRACE_FROZEN is not set. This has the same effect as changing TASK_TRACED to __TASK_TRACED as all of the wake_ups that use TASK_KILLABLE go through signal_wake_up. Don't set TASK_TRACED if fatal_signal_pending so that the code continues not to sleep if there was a pending fatal signal before ptrace_stop is called. With TASK_WAKEKILL no longer present in TASK_TRACED signal_pending_state will no longer prevent ptrace_stop from sleeping if there is a pending fatal signal. Previously the __state value of __TASK_TRACED was changed to TASK_RUNNING when woken up or back to TASK_TRACED when the code was left in ptrace_stop. Now when woken up ptrace_stop now clears JOBCTL_PTRACE_FROZEN and when left sleeping ptrace_unfreezed_traced clears JOBCTL_PTRACE_FROZEN. Signed-off-by: "Eric W. Biederman" --- include/linux/sched.h | 2 +- include/linux/sched/jobctl.h | 2 ++ include/linux/sched/signal.h | 8 +++++++- kernel/ptrace.c | 21 ++++++++------------- kernel/signal.c | 9 +++------ 5 files changed, 21 insertions(+), 21 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index d5e3c00b74e1..610f2fdb1e2c 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -103,7 +103,7 @@ struct task_group; /* Convenience macros for the sake of set_current_state: */ #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE) #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED) -#define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED) +#define TASK_TRACED __TASK_TRACED #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD) diff --git a/include/linux/sched/jobctl.h b/include/linux/sched/jobctl.h index fa067de9f1a9..d556c3425963 100644 --- a/include/linux/sched/jobctl.h +++ b/include/linux/sched/jobctl.h @@ -19,6 +19,7 @@ struct task_struct; #define JOBCTL_TRAPPING_BIT 21 /* switching to TRACED */ #define JOBCTL_LISTENING_BIT 22 /* ptracer is listening for events */ #define JOBCTL_TRAP_FREEZE_BIT 23 /* trap for cgroup freezer */ +#define JOBCTL_PTRACE_FROZEN_BIT 24 /* frozen for ptrace */ #define JOBCTL_STOP_DEQUEUED (1UL << JOBCTL_STOP_DEQUEUED_BIT) #define JOBCTL_STOP_PENDING (1UL << JOBCTL_STOP_PENDING_BIT) @@ -28,6 +29,7 @@ struct task_struct; #define JOBCTL_TRAPPING (1UL << JOBCTL_TRAPPING_BIT) #define JOBCTL_LISTENING (1UL << JOBCTL_LISTENING_BIT) #define JOBCTL_TRAP_FREEZE (1UL << JOBCTL_TRAP_FREEZE_BIT) +#define JOBCTL_PTRACE_FROZEN (1UL << JOBCTL_PTRACE_FROZEN_BIT) #define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY) #define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK) diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 3c8b34876744..35af34eeee9e 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -437,7 +437,13 @@ extern void signal_wake_up_state(struct task_struct *t, unsigned int state); static inline void signal_wake_up(struct task_struct *t, bool resume) { - signal_wake_up_state(t, resume ? TASK_WAKEKILL : 0); + unsigned int state = 0; + if (resume) { + state = TASK_WAKEKILL; + if (!(t->jobctl & JOBCTL_PTRACE_FROZEN)) + state |= __TASK_TRACED; + } + signal_wake_up_state(t, state); } static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume) { diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 43da5764b6f3..644eb7439d01 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -197,7 +197,7 @@ static bool ptrace_freeze_traced(struct task_struct *task) spin_lock_irq(&task->sighand->siglock); if (task_is_traced(task) && !looks_like_a_spurious_pid(task) && !__fatal_signal_pending(task)) { - WRITE_ONCE(task->__state, __TASK_TRACED); + task->jobctl |= JOBCTL_PTRACE_FROZEN; ret = true; } spin_unlock_irq(&task->sighand->siglock); @@ -207,23 +207,19 @@ static bool ptrace_freeze_traced(struct task_struct *task) static void ptrace_unfreeze_traced(struct task_struct *task) { - if (READ_ONCE(task->__state) != __TASK_TRACED) - return; - - WARN_ON(!task->ptrace || task->parent != current); + unsigned long flags; /* - * PTRACE_LISTEN can allow ptrace_trap_notify to wake us up remotely. - * Recheck state under the lock to close this race. + * The child may be awake and may have cleared + * JOBCTL_PTRACE_FROZEN (see ptrace_resume). The child will + * not set JOBCTL_PTRACE_FROZEN or enter __TASK_TRACED anew. */ - spin_lock_irq(&task->sighand->siglock); - if (READ_ONCE(task->__state) == __TASK_TRACED) { + if (lock_task_sighand(task, &flags)) { + task->jobctl &= ~JOBCTL_PTRACE_FROZEN; if (__fatal_signal_pending(task)) wake_up_state(task, __TASK_TRACED); - else - WRITE_ONCE(task->__state, TASK_TRACED); + unlock_task_sighand(task, &flags); } - spin_unlock_irq(&task->sighand->siglock); } /** @@ -256,7 +252,6 @@ static int ptrace_check_attach(struct task_struct *child, bool ignore_state) */ read_lock(&tasklist_lock); if (child->ptrace && child->parent == current) { - WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED); /* * child->sighand can't be NULL, release_task() * does ptrace_unlink() before __exit_signal(). diff --git a/kernel/signal.c b/kernel/signal.c index 3fd2ce133387..5cf268982a7e 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2209,11 +2209,8 @@ static int ptrace_stop(int exit_code, int why, int clear_code, spin_lock_irq(¤t->sighand->siglock); } - /* - * schedule() will not sleep if there is a pending signal that - * can awaken the task. - */ - set_special_state(TASK_TRACED); + if (!__fatal_signal_pending(current)) + set_special_state(TASK_TRACED); /* * We're committing to trapping. TRACED should be visible before @@ -2321,7 +2318,7 @@ static int ptrace_stop(int exit_code, int why, int clear_code, current->exit_code = 0; /* LISTENING can be set only during STOP traps, clear it */ - current->jobctl &= ~JOBCTL_LISTENING; + current->jobctl &= ~(JOBCTL_LISTENING | JOBCTL_PTRACE_FROZEN); /* * Queued signals ignored us while we were stopped for tracing. From patchwork Fri Apr 29 21:48:33 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: 12832895 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 41102C433F5 for ; Fri, 29 Apr 2022 21:49:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239614AbiD2Vwl (ORCPT ); Fri, 29 Apr 2022 17:52:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239601AbiD2Vwk (ORCPT ); Fri, 29 Apr 2022 17:52:40 -0400 Received: from out01.mta.xmission.com (out01.mta.xmission.com [166.70.13.231]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A6986DBD0E; Fri, 29 Apr 2022 14:49:20 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:49974) by out01.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUJ-007OFZ-R1; Fri, 29 Apr 2022 15:49:19 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUI-007RIp-M8; Fri, 29 Apr 2022 15:49:19 -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" Date: Fri, 29 Apr 2022 16:48:33 -0500 Message-Id: <20220429214837.386518-8-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYUI-007RIp-M8;;;mid=<20220429214837.386518-8-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX1/sQrokaS8H/jH+t68bDpORX+pJ4dW0els= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 08/12] ptrace: Remove arch_ptrace_attach X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org The last remaining implementation of arch_ptrace_attach is ia64's ptrace_attach_sync_user_rbs which was added at the end of 2007 in commit aa91a2e90044 ("[IA64] Synchronize RBS on PTRACE_ATTACH"). Reading the comments and examining the code ptrace_attach_sync_user_rbs has the sole purpose of saving registers to the stack when ptrace_attach changes TASK_STOPPED to TASK_TRACED. In all other cases arch_ptrace_stop takes care of the register saving. In commit d79fdd6d96f4 ("ptrace: Clean transitions between TASK_STOPPED and TRACED") modified ptrace_attach to wake up the thread and enter ptrace_stop normally even when the thread starts out stopped. This makes ptrace_attach_sync_user_rbs completely unnecessary. So just remove it. Cc: linux-ia64@vger.kernel.org Signed-off-by: "Eric W. Biederman" --- arch/ia64/include/asm/ptrace.h | 4 --- arch/ia64/kernel/ptrace.c | 57 ---------------------------------- kernel/ptrace.c | 18 ----------- 3 files changed, 79 deletions(-) diff --git a/arch/ia64/include/asm/ptrace.h b/arch/ia64/include/asm/ptrace.h index a10a498eede1..402874489890 100644 --- a/arch/ia64/include/asm/ptrace.h +++ b/arch/ia64/include/asm/ptrace.h @@ -139,10 +139,6 @@ static inline long regs_return_value(struct pt_regs *regs) #define arch_ptrace_stop_needed() \ (!test_thread_flag(TIF_RESTORE_RSE)) - extern void ptrace_attach_sync_user_rbs (struct task_struct *); - #define arch_ptrace_attach(child) \ - ptrace_attach_sync_user_rbs(child) - #define arch_has_single_step() (1) #define arch_has_block_step() (1) diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c index a19acd9f5e1f..a45f529046c3 100644 --- a/arch/ia64/kernel/ptrace.c +++ b/arch/ia64/kernel/ptrace.c @@ -617,63 +617,6 @@ void ia64_sync_krbs(void) unw_init_running(do_sync_rbs, ia64_sync_kernel_rbs); } -/* - * After PTRACE_ATTACH, a thread's register backing store area in user - * space is assumed to contain correct data whenever the thread is - * stopped. arch_ptrace_stop takes care of this on tracing stops. - * But if the child was already stopped for job control when we attach - * to it, then it might not ever get into ptrace_stop by the time we - * want to examine the user memory containing the RBS. - */ -void -ptrace_attach_sync_user_rbs (struct task_struct *child) -{ - int stopped = 0; - struct unw_frame_info info; - - /* - * If the child is in TASK_STOPPED, we need to change that to - * TASK_TRACED momentarily while we operate on it. This ensures - * that the child won't be woken up and return to user mode while - * we are doing the sync. (It can only be woken up for SIGKILL.) - */ - - read_lock(&tasklist_lock); - if (child->sighand) { - spin_lock_irq(&child->sighand->siglock); - if (READ_ONCE(child->__state) == TASK_STOPPED && - !test_and_set_tsk_thread_flag(child, TIF_RESTORE_RSE)) { - set_notify_resume(child); - - WRITE_ONCE(child->__state, TASK_TRACED); - stopped = 1; - } - spin_unlock_irq(&child->sighand->siglock); - } - read_unlock(&tasklist_lock); - - if (!stopped) - return; - - unw_init_from_blocked_task(&info, child); - do_sync_rbs(&info, ia64_sync_user_rbs); - - /* - * Now move the child back into TASK_STOPPED if it should be in a - * job control stop, so that SIGCONT can be used to wake it up. - */ - read_lock(&tasklist_lock); - if (child->sighand) { - spin_lock_irq(&child->sighand->siglock); - if (READ_ONCE(child->__state) == TASK_TRACED && - (child->signal->flags & SIGNAL_STOP_STOPPED)) { - WRITE_ONCE(child->__state, TASK_STOPPED); - } - spin_unlock_irq(&child->sighand->siglock); - } - read_unlock(&tasklist_lock); -} - /* * Write f32-f127 back to task->thread.fph if it has been modified. */ diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 644eb7439d01..22041531adf6 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -1280,10 +1280,6 @@ int ptrace_request(struct task_struct *child, long request, return ret; } -#ifndef arch_ptrace_attach -#define arch_ptrace_attach(child) do { } while (0) -#endif - SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, unsigned long, data) { @@ -1292,8 +1288,6 @@ SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, if (request == PTRACE_TRACEME) { ret = ptrace_traceme(); - if (!ret) - arch_ptrace_attach(current); goto out; } @@ -1305,12 +1299,6 @@ SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr, if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { ret = ptrace_attach(child, request, addr, data); - /* - * Some architectures need to do book-keeping after - * a ptrace attach. - */ - if (!ret) - arch_ptrace_attach(child); goto out_put_task_struct; } @@ -1450,12 +1438,6 @@ COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid, if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) { ret = ptrace_attach(child, request, addr, data); - /* - * Some architectures need to do book-keeping after - * a ptrace attach. - */ - if (!ret) - arch_ptrace_attach(child); goto out_put_task_struct; } From patchwork Fri Apr 29 21:48:34 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: 12832943 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 C5E0FC433EF for ; Fri, 29 Apr 2022 22:07:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381273AbiD2WLB (ORCPT ); Fri, 29 Apr 2022 18:11:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46656 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1381267AbiD2WKr (ORCPT ); Fri, 29 Apr 2022 18:10:47 -0400 Received: from out02.mta.xmission.com (out02.mta.xmission.com [166.70.13.232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A9DBBDC596; Fri, 29 Apr 2022 15:07:27 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:54896) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUN-00AIKX-3y; Fri, 29 Apr 2022 15:49:23 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUL-007RIp-QC; Fri, 29 Apr 2022 15:49:22 -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" Date: Fri, 29 Apr 2022 16:48:34 -0500 Message-Id: <20220429214837.386518-9-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYUL-007RIp-QC;;;mid=<20220429214837.386518-9-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX1+z4wBZ5SUESkMZCigxf10zSEqW++hadmI= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 09/12] ptrace: Always take siglock in ptrace_resume X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Make code analysis simpler and future changes easier by always taking siglock in ptrace_resume. Signed-off-by: "Eric W. Biederman" --- kernel/ptrace.c | 13 ++----------- 1 file changed, 2 insertions(+), 11 deletions(-) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 22041531adf6..c1c99e8be147 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -845,8 +845,6 @@ static long ptrace_get_rseq_configuration(struct task_struct *task, static int ptrace_resume(struct task_struct *child, long request, unsigned long data) { - bool need_siglock; - if (!valid_signal(data)) return -EIO; @@ -882,18 +880,11 @@ static int ptrace_resume(struct task_struct *child, long request, * Note that we need siglock even if ->exit_code == data and/or this * status was not reported yet, the new status must not be cleared by * wait_task_stopped() after resume. - * - * If data == 0 we do not care if wait_task_stopped() reports the old - * status and clears the code too; this can't race with the tracee, it - * takes siglock after resume. */ - need_siglock = data && !thread_group_empty(current); - if (need_siglock) - spin_lock_irq(&child->sighand->siglock); + spin_lock_irq(&child->sighand->siglock); child->exit_code = data; wake_up_state(child, __TASK_TRACED); - if (need_siglock) - spin_unlock_irq(&child->sighand->siglock); + spin_unlock_irq(&child->sighand->siglock); return 0; } From patchwork Fri Apr 29 21:48:35 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: 12832944 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 8ECEFC433F5 for ; Fri, 29 Apr 2022 22:07:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356742AbiD2WLA (ORCPT ); Fri, 29 Apr 2022 18:11:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46516 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234141AbiD2WKp (ORCPT ); Fri, 29 Apr 2022 18:10:45 -0400 Received: from out02.mta.xmission.com (out02.mta.xmission.com [166.70.13.232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4D900DBD36; Fri, 29 Apr 2022 15:07:26 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:54950) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUQ-00AILf-7G; Fri, 29 Apr 2022 15:49:26 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUP-007RIp-3B; Fri, 29 Apr 2022 15:49:25 -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" Date: Fri, 29 Apr 2022 16:48:35 -0500 Message-Id: <20220429214837.386518-10-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYUP-007RIp-3B;;;mid=<20220429214837.386518-10-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX18BszdtWlY/czZ0kfmE2y8Ll+tNMQpUINU= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 10/12] ptrace: Only return signr from ptrace_stop if it was provided X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org In ptrace_stop a ptrace_unlink or SIGKILL can occur either after siglock is dropped or after tasklist_lock is dropped. At either point the result can be that ptrace will continue and not stop at schedule. This means that there are cases where the current logic fails to handle the fact that ptrace_stop did not actually stop, and can potentially cause ptrace_report_syscall to attempt to deliver a signal. Instead of attempting to detect in ptrace_stop when it fails to stop update ptrace_resume and ptrace_detach to set a flag to indicate that the signal to continue with has be set. Use that new flag to decided how to set return signal. Signed-off-by: "Eric W. Biederman" --- include/linux/sched/jobctl.h | 2 ++ kernel/ptrace.c | 5 +++++ kernel/signal.c | 12 ++++++------ 3 files changed, 13 insertions(+), 6 deletions(-) diff --git a/include/linux/sched/jobctl.h b/include/linux/sched/jobctl.h index d556c3425963..2ff1bcd63cf4 100644 --- a/include/linux/sched/jobctl.h +++ b/include/linux/sched/jobctl.h @@ -20,6 +20,7 @@ struct task_struct; #define JOBCTL_LISTENING_BIT 22 /* ptracer is listening for events */ #define JOBCTL_TRAP_FREEZE_BIT 23 /* trap for cgroup freezer */ #define JOBCTL_PTRACE_FROZEN_BIT 24 /* frozen for ptrace */ +#define JOBCTL_PTRACE_SIGNR_BIT 25 /* ptrace signal number */ #define JOBCTL_STOP_DEQUEUED (1UL << JOBCTL_STOP_DEQUEUED_BIT) #define JOBCTL_STOP_PENDING (1UL << JOBCTL_STOP_PENDING_BIT) @@ -30,6 +31,7 @@ struct task_struct; #define JOBCTL_LISTENING (1UL << JOBCTL_LISTENING_BIT) #define JOBCTL_TRAP_FREEZE (1UL << JOBCTL_TRAP_FREEZE_BIT) #define JOBCTL_PTRACE_FROZEN (1UL << JOBCTL_PTRACE_FROZEN_BIT) +#define JOBCTL_PTRACE_SIGNR (1UL << JOBCTL_PTRACE_SIGNR_BIT) #define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY) #define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index c1c99e8be147..d80222251f60 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -596,7 +596,11 @@ static int ptrace_detach(struct task_struct *child, unsigned int data) * tasklist_lock avoids the race with wait_task_stopped(), see * the comment in ptrace_resume(). */ + spin_lock(&child->sighand->siglock); child->exit_code = data; + child->jobctl |= JOBCTL_PTRACE_SIGNR; + spin_unlock(&child->sighand->siglock); + __ptrace_detach(current, child); write_unlock_irq(&tasklist_lock); @@ -883,6 +887,7 @@ static int ptrace_resume(struct task_struct *child, long request, */ spin_lock_irq(&child->sighand->siglock); child->exit_code = data; + child->jobctl |= JOBCTL_PTRACE_SIGNR; wake_up_state(child, __TASK_TRACED); spin_unlock_irq(&child->sighand->siglock); diff --git a/kernel/signal.c b/kernel/signal.c index 5cf268982a7e..7cb27a27290a 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2193,7 +2193,6 @@ static int ptrace_stop(int exit_code, int why, int clear_code, __acquires(¤t->sighand->siglock) { bool gstop_done = false; - bool read_code = true; if (arch_ptrace_stop_needed()) { /* @@ -2299,9 +2298,6 @@ static int ptrace_stop(int exit_code, int why, int clear_code, /* tasklist protects us from ptrace_freeze_traced() */ __set_current_state(TASK_RUNNING); - read_code = false; - if (clear_code) - exit_code = 0; read_unlock(&tasklist_lock); } @@ -2311,14 +2307,18 @@ static int ptrace_stop(int exit_code, int why, int clear_code, * any signal-sending on another CPU that wants to examine it. */ spin_lock_irq(¤t->sighand->siglock); - if (read_code) + /* Did userspace perhaps provide a signal to resume with? */ + if (current->jobctl & JOBCTL_PTRACE_SIGNR) exit_code = current->exit_code; + else if (clear_code) + exit_code = 0; + current->last_siginfo = NULL; current->ptrace_message = 0; current->exit_code = 0; /* LISTENING can be set only during STOP traps, clear it */ - current->jobctl &= ~(JOBCTL_LISTENING | JOBCTL_PTRACE_FROZEN); + current->jobctl &= ~(JOBCTL_LISTENING | JOBCTL_PTRACE_FROZEN | JOBCTL_PTRACE_SIGNR); /* * Queued signals ignored us while we were stopped for tracing. From patchwork Fri Apr 29 21:48:36 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: 12832942 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 757D0C433F5 for ; Fri, 29 Apr 2022 22:07:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381257AbiD2WKp (ORCPT ); Fri, 29 Apr 2022 18:10:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46394 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1381167AbiD2WKo (ORCPT ); Fri, 29 Apr 2022 18:10:44 -0400 Received: from out02.mta.xmission.com (out02.mta.xmission.com [166.70.13.232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 144B5DBD0E; Fri, 29 Apr 2022 15:07:25 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:55002) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUT-00AIMf-B9; Fri, 29 Apr 2022 15:49:29 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUS-007RIp-6h; Fri, 29 Apr 2022 15:49:28 -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" Date: Fri, 29 Apr 2022 16:48:36 -0500 Message-Id: <20220429214837.386518-11-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYUS-007RIp-6h;;;mid=<20220429214837.386518-11-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX18Rvz6pahoBBVqRiRjYubwQ90GavkWSLh0= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 11/12] ptrace: Always call schedule in ptrace_stop X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Stop testing for !current->ptrace and setting __state to TASK_RUNNING. The code in __ptrace_unlink wakes up the child with ptrace_signal_wake_up which will set __state to TASK_RUNNING. This leaves the only thing ptrace_stop needs to do is to send the signals. Make the signals sending conditional upon current->ptrace so that the correct signals are sent to the parent. After that call schedule and let the fact that __state == TASK_RUNNING keep the code from sleeping in schedule. Now that it is easy to see that ptrace_stop always sleeps in ptrace_stop after ptrace_freeze_trace succeeds modify ptrace_check_attach to warn if wait_task_inactive fails. Signed-off-by: "Eric W. Biederman" --- kernel/ptrace.c | 14 +++------- kernel/signal.c | 68 ++++++++++++++++++------------------------------- 2 files changed, 28 insertions(+), 54 deletions(-) diff --git a/kernel/ptrace.c b/kernel/ptrace.c index d80222251f60..c1afebd2e8f3 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -261,17 +261,9 @@ static int ptrace_check_attach(struct task_struct *child, bool ignore_state) } read_unlock(&tasklist_lock); - if (!ret && !ignore_state) { - if (!wait_task_inactive(child, __TASK_TRACED)) { - /* - * This can only happen if may_ptrace_stop() fails and - * ptrace_stop() changes ->state back to TASK_RUNNING, - * so we should not worry about leaking __TASK_TRACED. - */ - WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED); - ret = -ESRCH; - } - } + if (!ret && !ignore_state && + WARN_ON_ONCE(!wait_task_inactive(child, __TASK_TRACED))) + ret = -ESRCH; return ret; } diff --git a/kernel/signal.c b/kernel/signal.c index 7cb27a27290a..4cae3f47f664 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -2255,51 +2255,33 @@ static int ptrace_stop(int exit_code, int why, int clear_code, spin_unlock_irq(¤t->sighand->siglock); read_lock(&tasklist_lock); - if (likely(current->ptrace)) { - /* - * Notify parents of the stop. - * - * While ptraced, there are two parents - the ptracer and - * the real_parent of the group_leader. The ptracer should - * know about every stop while the real parent is only - * interested in the completion of group stop. The states - * for the two don't interact with each other. Notify - * separately unless they're gonna be duplicates. - */ + /* + * Notify parents of the stop. + * + * While ptraced, there are two parents - the ptracer and + * the real_parent of the group_leader. The ptracer should + * know about every stop while the real parent is only + * interested in the completion of group stop. The states + * for the two don't interact with each other. Notify + * separately unless they're gonna be duplicates. + */ + if (current->ptrace) do_notify_parent_cldstop(current, true, why); - if (gstop_done && ptrace_reparented(current)) - do_notify_parent_cldstop(current, false, why); - - /* - * Don't want to allow preemption here, because - * sys_ptrace() needs this task to be inactive. - * - * XXX: implement read_unlock_no_resched(). - */ - preempt_disable(); - read_unlock(&tasklist_lock); - cgroup_enter_frozen(); - preempt_enable_no_resched(); - freezable_schedule(); - cgroup_leave_frozen(true); - } else { - /* - * By the time we got the lock, our tracer went away. - * Don't drop the lock yet, another tracer may come. - * - * If @gstop_done, the ptracer went away between group stop - * completion and here. During detach, it would have set - * JOBCTL_STOP_PENDING on us and we'll re-enter - * TASK_STOPPED in do_signal_stop() on return, so notifying - * the real parent of the group stop completion is enough. - */ - if (gstop_done) - do_notify_parent_cldstop(current, false, why); + if (gstop_done && (!current->ptrace || ptrace_reparented(current))) + do_notify_parent_cldstop(current, false, why); - /* tasklist protects us from ptrace_freeze_traced() */ - __set_current_state(TASK_RUNNING); - read_unlock(&tasklist_lock); - } + /* + * Don't want to allow preemption here, because + * sys_ptrace() needs this task to be inactive. + * + * XXX: implement read_unlock_no_resched(). + */ + preempt_disable(); + read_unlock(&tasklist_lock); + cgroup_enter_frozen(); + preempt_enable_no_resched(); + freezable_schedule(); + cgroup_leave_frozen(true); /* * We are back. Now reacquire the siglock before touching From patchwork Fri Apr 29 21:48:37 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: 12832897 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 3E271C433F5 for ; Fri, 29 Apr 2022 21:49:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239601AbiD2Vwz (ORCPT ); Fri, 29 Apr 2022 17:52:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47868 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1346050AbiD2Vwx (ORCPT ); Fri, 29 Apr 2022 17:52:53 -0400 Received: from out03.mta.xmission.com (out03.mta.xmission.com [166.70.13.233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0017EDBD29; Fri, 29 Apr 2022 14:49:33 -0700 (PDT) Received: from in02.mta.xmission.com ([166.70.13.52]:52748) by out03.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUW-001soO-Ol; Fri, 29 Apr 2022 15:49:32 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:36464 helo=localhost.localdomain) by in02.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1nkYUV-007RIp-BQ; Fri, 29 Apr 2022 15:49:32 -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" Date: Fri, 29 Apr 2022 16:48:37 -0500 Message-Id: <20220429214837.386518-12-ebiederm@xmission.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> References: <87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org> MIME-Version: 1.0 X-XM-SPF: eid=1nkYUV-007RIp-BQ;;;mid=<20220429214837.386518-12-ebiederm@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX18HggEQ00jNKxp5LMOxYEPvBJdBGOPmWYg= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: [PATCH v2 12/12] sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Currently ptrace_stop() / do_signal_stop() rely on the special states TASK_TRACED and TASK_STOPPED resp. to keep unique state. That is, this state exists only in task->__state and nowhere else. There's two spots of bother with this: - PREEMPT_RT has task->saved_state which complicates matters, meaning task_is_{traced,stopped}() needs to check an additional variable. - An alternative freezer implementation that itself relies on a special TASK state would loose TASK_TRACED/TASK_STOPPED and will result in misbehaviour. As such, add additional state to task->jobctl to track this state outside of task->__state. NOTE: this doesn't actually fix anything yet, just adds extra state. --EWB * didn't add a unnecessary newline in signal.h * Update t->jobctl in signal_wake_up and ptrace_signal_wake_up instead of in signal_wake_up_state. This prevents the clearing of TASK_STOPPED and TASK_TRACED from getting lost. * Added warnings if JOBCTL_STOPPED or JOBCTL_TRACED are not cleared Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20220421150654.757693825@infradead.org Signed-off-by: Eric W. Biederman --- include/linux/sched.h | 8 +++----- include/linux/sched/jobctl.h | 6 ++++++ include/linux/sched/signal.h | 17 ++++++++++++++--- kernel/ptrace.c | 17 +++++++++++++---- kernel/signal.c | 16 +++++++++++++--- 5 files changed, 49 insertions(+), 15 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 610f2fdb1e2c..cbe5c899599c 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -118,11 +118,9 @@ struct task_group; #define task_is_running(task) (READ_ONCE((task)->__state) == TASK_RUNNING) -#define task_is_traced(task) ((READ_ONCE(task->__state) & __TASK_TRACED) != 0) - -#define task_is_stopped(task) ((READ_ONCE(task->__state) & __TASK_STOPPED) != 0) - -#define task_is_stopped_or_traced(task) ((READ_ONCE(task->__state) & (__TASK_STOPPED | __TASK_TRACED)) != 0) +#define task_is_traced(task) ((READ_ONCE(task->jobctl) & JOBCTL_TRACED) != 0) +#define task_is_stopped(task) ((READ_ONCE(task->jobctl) & JOBCTL_STOPPED) != 0) +#define task_is_stopped_or_traced(task) ((READ_ONCE(task->jobctl) & (JOBCTL_STOPPED | JOBCTL_TRACED)) != 0) /* * Special states are those that do not use the normal wait-loop pattern. See diff --git a/include/linux/sched/jobctl.h b/include/linux/sched/jobctl.h index 2ff1bcd63cf4..9c0b917de2f9 100644 --- a/include/linux/sched/jobctl.h +++ b/include/linux/sched/jobctl.h @@ -22,6 +22,9 @@ struct task_struct; #define JOBCTL_PTRACE_FROZEN_BIT 24 /* frozen for ptrace */ #define JOBCTL_PTRACE_SIGNR_BIT 25 /* ptrace signal number */ +#define JOBCTL_STOPPED_BIT 26 /* do_signal_stop() */ +#define JOBCTL_TRACED_BIT 27 /* ptrace_stop() */ + #define JOBCTL_STOP_DEQUEUED (1UL << JOBCTL_STOP_DEQUEUED_BIT) #define JOBCTL_STOP_PENDING (1UL << JOBCTL_STOP_PENDING_BIT) #define JOBCTL_STOP_CONSUME (1UL << JOBCTL_STOP_CONSUME_BIT) @@ -33,6 +36,9 @@ struct task_struct; #define JOBCTL_PTRACE_FROZEN (1UL << JOBCTL_PTRACE_FROZEN_BIT) #define JOBCTL_PTRACE_SIGNR (1UL << JOBCTL_PTRACE_SIGNR_BIT) +#define JOBCTL_STOPPED (1UL << JOBCTL_STOPPED_BIT) +#define JOBCTL_TRACED (1UL << JOBCTL_TRACED_BIT) + #define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY) #define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK) diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index 35af34eeee9e..4dcce2bbf1fb 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -294,8 +294,10 @@ static inline int kernel_dequeue_signal(void) static inline void kernel_signal_stop(void) { spin_lock_irq(¤t->sighand->siglock); - if (current->jobctl & JOBCTL_STOP_DEQUEUED) + if (current->jobctl & JOBCTL_STOP_DEQUEUED) { + current->jobctl |= JOBCTL_STOPPED; set_special_state(TASK_STOPPED); + } spin_unlock_irq(¤t->sighand->siglock); schedule(); @@ -439,15 +441,24 @@ static inline void signal_wake_up(struct task_struct *t, bool resume) { unsigned int state = 0; if (resume) { + unsigned long jmask = JOBCTL_STOPPED; state = TASK_WAKEKILL; - if (!(t->jobctl & JOBCTL_PTRACE_FROZEN)) + if (!(t->jobctl & JOBCTL_PTRACE_FROZEN)) { + jmask |= JOBCTL_TRACED; state |= __TASK_TRACED; + } + t->jobctl &= ~jmask; } signal_wake_up_state(t, state); } static inline void ptrace_signal_wake_up(struct task_struct *t, bool resume) { - signal_wake_up_state(t, resume ? __TASK_TRACED : 0); + unsigned int state = 0; + if (resume) { + t->jobctl &= ~JOBCTL_TRACED; + state = __TASK_TRACED; + } + signal_wake_up_state(t, state); } void task_join_group_stop(struct task_struct *task); diff --git a/kernel/ptrace.c b/kernel/ptrace.c index c1afebd2e8f3..38913801717f 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -185,7 +185,12 @@ static bool looks_like_a_spurious_pid(struct task_struct *task) return true; } -/* Ensure that nothing can wake it up, even SIGKILL */ +/* + * Ensure that nothing can wake it up, even SIGKILL + * + * A task is switched to this state while a ptrace operation is in progress; + * such that the ptrace operation is uninterruptible. + */ static bool ptrace_freeze_traced(struct task_struct *task) { bool ret = false; @@ -216,8 +221,10 @@ static void ptrace_unfreeze_traced(struct task_struct *task) */ if (lock_task_sighand(task, &flags)) { task->jobctl &= ~JOBCTL_PTRACE_FROZEN; - if (__fatal_signal_pending(task)) + if (__fatal_signal_pending(task)) { + task->jobctl &= ~TASK_TRACED; wake_up_state(task, __TASK_TRACED); + } unlock_task_sighand(task, &flags); } } @@ -462,8 +469,10 @@ static int ptrace_attach(struct task_struct *task, long request, * in and out of STOPPED are protected by siglock. */ if (task_is_stopped(task) && - task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) + task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING)) { + task->jobctl &= ~JOBCTL_STOPPED; signal_wake_up_state(task, __TASK_STOPPED); + } spin_unlock(&task->sighand->siglock); @@ -879,7 +888,7 @@ static int ptrace_resume(struct task_struct *child, long request, */ spin_lock_irq(&child->sighand->siglock); child->exit_code = data; - child->jobctl |= JOBCTL_PTRACE_SIGNR; + child->jobctl = (child->jobctl | JOBCTL_PTRACE_SIGNR) & ~JOBCTL_TRACED; wake_up_state(child, __TASK_TRACED); spin_unlock_irq(&child->sighand->siglock); diff --git a/kernel/signal.c b/kernel/signal.c index 4cae3f47f664..d6573abbc169 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -762,7 +762,10 @@ static int dequeue_synchronous_signal(kernel_siginfo_t *info) */ void signal_wake_up_state(struct task_struct *t, unsigned int state) { + lockdep_assert_held(&t->sighand->siglock); + set_tsk_thread_flag(t, TIF_SIGPENDING); + /* * TASK_WAKEKILL also means wake it up in the stopped/traced/killable * case. We don't check t->state here because there is a race with it @@ -930,9 +933,10 @@ static bool prepare_signal(int sig, struct task_struct *p, bool force) for_each_thread(p, t) { flush_sigqueue_mask(&flush, &t->pending); task_clear_jobctl_pending(t, JOBCTL_STOP_PENDING); - if (likely(!(t->ptrace & PT_SEIZED))) + if (likely(!(t->ptrace & PT_SEIZED))) { + t->jobctl &= ~JOBCTL_STOPPED; wake_up_state(t, __TASK_STOPPED); - else + } else ptrace_trap_notify(t); } @@ -2208,8 +2212,10 @@ static int ptrace_stop(int exit_code, int why, int clear_code, spin_lock_irq(¤t->sighand->siglock); } - if (!__fatal_signal_pending(current)) + if (!__fatal_signal_pending(current)) { set_special_state(TASK_TRACED); + current->jobctl |= JOBCTL_TRACED; + } /* * We're committing to trapping. TRACED should be visible before @@ -2301,6 +2307,7 @@ static int ptrace_stop(int exit_code, int why, int clear_code, /* LISTENING can be set only during STOP traps, clear it */ current->jobctl &= ~(JOBCTL_LISTENING | JOBCTL_PTRACE_FROZEN | JOBCTL_PTRACE_SIGNR); + WARN_ON_ONCE(current->jobctl & JOBCTL_TRACED); /* * Queued signals ignored us while we were stopped for tracing. @@ -2433,6 +2440,7 @@ static bool do_signal_stop(int signr) if (task_participate_group_stop(current)) notify = CLD_STOPPED; + current->jobctl |= JOBCTL_STOPPED; set_special_state(TASK_STOPPED); spin_unlock_irq(¤t->sighand->siglock); @@ -2454,6 +2462,8 @@ static bool do_signal_stop(int signr) /* Now we don't run again until woken by SIGCONT or SIGKILL */ cgroup_enter_frozen(); freezable_schedule(); + + WARN_ON_ONCE(READ_ONCE(current->jobctl) & JOBCTL_STOPPED); return true; } else { /*