From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: [patch V2 01/29] tracing: Cleanup stack trace code Date: Thu, 18 Apr 2019 10:41:20 +0200 Message-ID: <20190418084253.142712304@linutronix.de> References: <20190418084119.056416939@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: LKML Cc: Mike Snitzer , David Airlie , Catalin Marinas , Joonas Lahtinen , dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, dm-devel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, Alexander Potapenko , Christoph Lameter , Christoph Hellwig , Alasdair Kergon , linux-arch-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, x86-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, kasan-dev-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, Johannes Thumshirn , Andrey Ryabinin , Alexey Dobriyan , intel-gfx-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, David Rientjes , Maarten Lankhorst , Akinobu Mita , Steven Rostedt , Josef Bacik , Rodrigo Vivi , Mike Rapoport List-Id: iommu@lists.linux-foundation.org - Remove the extra array member of stack_dump_trace[]. It's not required as the stack tracer stores at max array size - 1 entries so there is still an empty slot. - Make variables which are only used in trace_stack.c static. - Simplify the enable/disable logic. - Rename stack_trace_print() as it's using the stack_trace_ namespace. Free the name up for stack trace related functions. Signed-off-by: Thomas Gleixner Cc: Steven Rostedt --- V2: Add more cleanups and use print_max_stack() as requested by Steven. --- include/linux/ftrace.h | 18 ++++-------------- kernel/trace/trace_stack.c | 36 ++++++++++++------------------------ 2 files changed, 16 insertions(+), 38 deletions(-) --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -241,21 +241,11 @@ static inline void ftrace_free_mem(struc #ifdef CONFIG_STACK_TRACER -#define STACK_TRACE_ENTRIES 500 - -struct stack_trace; - -extern unsigned stack_trace_index[]; -extern struct stack_trace stack_trace_max; -extern unsigned long stack_trace_max_size; -extern arch_spinlock_t stack_trace_max_lock; - extern int stack_tracer_enabled; -void stack_trace_print(void); -int -stack_trace_sysctl(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, - loff_t *ppos); + +int stack_trace_sysctl(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ DECLARE_PER_CPU(int, disable_stack_tracer); --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -18,8 +18,10 @@ #include "trace.h" -static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES + 1]; -unsigned stack_trace_index[STACK_TRACE_ENTRIES]; +#define STACK_TRACE_ENTRIES 500 + +static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES]; +static unsigned stack_trace_index[STACK_TRACE_ENTRIES]; /* * Reserve one entry for the passed in ip. This will allow @@ -31,17 +33,16 @@ struct stack_trace stack_trace_max = { .entries = &stack_dump_trace[0], }; -unsigned long stack_trace_max_size; -arch_spinlock_t stack_trace_max_lock = +static unsigned long stack_trace_max_size; +static arch_spinlock_t stack_trace_max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; DEFINE_PER_CPU(int, disable_stack_tracer); static DEFINE_MUTEX(stack_sysctl_mutex); int stack_tracer_enabled; -static int last_stack_tracer_enabled; -void stack_trace_print(void) +static void print_max_stack(void) { long i; int size; @@ -61,16 +62,7 @@ void stack_trace_print(void) } } -/* - * When arch-specific code overrides this function, the following - * data should be filled up, assuming stack_trace_max_lock is held to - * prevent concurrent updates. - * stack_trace_index[] - * stack_trace_max - * stack_trace_max_size - */ -void __weak -check_stack(unsigned long ip, unsigned long *stack) +static void check_stack(unsigned long ip, unsigned long *stack) { unsigned long this_size, flags; unsigned long *p, *top, *start; static int tracer_frame; @@ -179,7 +171,7 @@ check_stack(unsigned long ip, unsigned l stack_trace_max.nr_entries = x; if (task_stack_end_corrupted(current)) { - stack_trace_print(); + print_max_stack(); BUG(); } @@ -412,23 +404,20 @@ stack_trace_sysctl(struct ctl_table *tab void __user *buffer, size_t *lenp, loff_t *ppos) { - int ret; + int ret, was_enabled; mutex_lock(&stack_sysctl_mutex); + was_enabled = !!stack_tracer_enabled; ret = proc_dointvec(table, write, buffer, lenp, ppos); - if (ret || !write || - (last_stack_tracer_enabled == !!stack_tracer_enabled)) + if (ret || !write || (was_enabled == !!stack_tracer_enabled)) goto out; - last_stack_tracer_enabled = !!stack_tracer_enabled; - if (stack_tracer_enabled) register_ftrace_function(&trace_ops); else unregister_ftrace_function(&trace_ops); - out: mutex_unlock(&stack_sysctl_mutex); return ret; @@ -444,7 +433,6 @@ static __init int enable_stacktrace(char strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE); stack_tracer_enabled = 1; - last_stack_tracer_enabled = 1; return 1; } __setup("stacktrace", enable_stacktrace); From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF3EDC10F0E for ; Thu, 18 Apr 2019 09:06:24 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id CC83A206B6 for ; Thu, 18 Apr 2019 09:06:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CC83A206B6 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linutronix.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 96FD514CB; Thu, 18 Apr 2019 09:06:16 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 3EE3214A3 for ; Thu, 18 Apr 2019 09:06:15 +0000 (UTC) X-Greylist: greylisting inactive for cl@linux.com in SQLgrey-1.7.6 X-Greylist: domain auto-whitelisted by SQLgrey-1.7.6 Received: from Galois.linutronix.de (Galois.linutronix.de [146.0.238.70]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 4EF36863; Thu, 18 Apr 2019 09:06:11 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtp (Exim 4.80) (envelope-from ) id 1hH2zZ-0001lv-2D; Thu, 18 Apr 2019 11:06:01 +0200 Message-Id: <20190418084253.142712304@linutronix.de> User-Agent: quilt/0.65 Date: Thu, 18 Apr 2019 10:41:20 +0200 From: Thomas Gleixner To: LKML Subject: [patch V2 01/29] tracing: Cleanup stack trace code References: <20190418084119.056416939@linutronix.de> MIME-Version: 1.0 Cc: Mike Snitzer , David Airlie , Catalin Marinas , Joonas Lahtinen , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, dm-devel@redhat.com, Alexander Potapenko , Christoph Lameter , Christoph Hellwig , Alasdair Kergon , linux-arch@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, Johannes Thumshirn , Andrey Ryabinin , Alexey Dobriyan , intel-gfx@lists.freedesktop.org, David Rientjes , Maarten Lankhorst , Akinobu Mita , Steven Rostedt , Josef Bacik , Rodrigo Vivi , Mike Rapoport , Jani Nikula , Andy Lutomirski , Josh Poimboeuf , David Sterba , Dmitry Vyukov , Chris Mason , Pekka Enberg , iommu@lists.linux-foundation.org, Daniel Vetter , Andrew Morton , Robin Murphy , linux-btrfs@vger.kernel.org X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org Message-ID: <20190418084120.zVZRoLB2GiAYHJDYmJGnSTuoDbh1WGkBSoFYzJ9LPqw@z> - Remove the extra array member of stack_dump_trace[]. It's not required as the stack tracer stores at max array size - 1 entries so there is still an empty slot. - Make variables which are only used in trace_stack.c static. - Simplify the enable/disable logic. - Rename stack_trace_print() as it's using the stack_trace_ namespace. Free the name up for stack trace related functions. Signed-off-by: Thomas Gleixner Cc: Steven Rostedt --- V2: Add more cleanups and use print_max_stack() as requested by Steven. --- include/linux/ftrace.h | 18 ++++-------------- kernel/trace/trace_stack.c | 36 ++++++++++++------------------------ 2 files changed, 16 insertions(+), 38 deletions(-) --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -241,21 +241,11 @@ static inline void ftrace_free_mem(struc #ifdef CONFIG_STACK_TRACER -#define STACK_TRACE_ENTRIES 500 - -struct stack_trace; - -extern unsigned stack_trace_index[]; -extern struct stack_trace stack_trace_max; -extern unsigned long stack_trace_max_size; -extern arch_spinlock_t stack_trace_max_lock; - extern int stack_tracer_enabled; -void stack_trace_print(void); -int -stack_trace_sysctl(struct ctl_table *table, int write, - void __user *buffer, size_t *lenp, - loff_t *ppos); + +int stack_trace_sysctl(struct ctl_table *table, int write, + void __user *buffer, size_t *lenp, + loff_t *ppos); /* DO NOT MODIFY THIS VARIABLE DIRECTLY! */ DECLARE_PER_CPU(int, disable_stack_tracer); --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -18,8 +18,10 @@ #include "trace.h" -static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES + 1]; -unsigned stack_trace_index[STACK_TRACE_ENTRIES]; +#define STACK_TRACE_ENTRIES 500 + +static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES]; +static unsigned stack_trace_index[STACK_TRACE_ENTRIES]; /* * Reserve one entry for the passed in ip. This will allow @@ -31,17 +33,16 @@ struct stack_trace stack_trace_max = { .entries = &stack_dump_trace[0], }; -unsigned long stack_trace_max_size; -arch_spinlock_t stack_trace_max_lock = +static unsigned long stack_trace_max_size; +static arch_spinlock_t stack_trace_max_lock = (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; DEFINE_PER_CPU(int, disable_stack_tracer); static DEFINE_MUTEX(stack_sysctl_mutex); int stack_tracer_enabled; -static int last_stack_tracer_enabled; -void stack_trace_print(void) +static void print_max_stack(void) { long i; int size; @@ -61,16 +62,7 @@ void stack_trace_print(void) } } -/* - * When arch-specific code overrides this function, the following - * data should be filled up, assuming stack_trace_max_lock is held to - * prevent concurrent updates. - * stack_trace_index[] - * stack_trace_max - * stack_trace_max_size - */ -void __weak -check_stack(unsigned long ip, unsigned long *stack) +static void check_stack(unsigned long ip, unsigned long *stack) { unsigned long this_size, flags; unsigned long *p, *top, *start; static int tracer_frame; @@ -179,7 +171,7 @@ check_stack(unsigned long ip, unsigned l stack_trace_max.nr_entries = x; if (task_stack_end_corrupted(current)) { - stack_trace_print(); + print_max_stack(); BUG(); } @@ -412,23 +404,20 @@ stack_trace_sysctl(struct ctl_table *tab void __user *buffer, size_t *lenp, loff_t *ppos) { - int ret; + int ret, was_enabled; mutex_lock(&stack_sysctl_mutex); + was_enabled = !!stack_tracer_enabled; ret = proc_dointvec(table, write, buffer, lenp, ppos); - if (ret || !write || - (last_stack_tracer_enabled == !!stack_tracer_enabled)) + if (ret || !write || (was_enabled == !!stack_tracer_enabled)) goto out; - last_stack_tracer_enabled = !!stack_tracer_enabled; - if (stack_tracer_enabled) register_ftrace_function(&trace_ops); else unregister_ftrace_function(&trace_ops); - out: mutex_unlock(&stack_sysctl_mutex); return ret; @@ -444,7 +433,6 @@ static __init int enable_stacktrace(char strncpy(stack_trace_filter_buf, str + len, COMMAND_LINE_SIZE); stack_tracer_enabled = 1; - last_stack_tracer_enabled = 1; return 1; } __setup("stacktrace", enable_stacktrace); _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu