From patchwork Thu Apr 18 08:41:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 10907759 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6839013B5 for ; Thu, 18 Apr 2019 17:57:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4F87F28D4E for ; Thu, 18 Apr 2019 17:57:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 417DA28D50; Thu, 18 Apr 2019 17:57:54 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id B7A9228D4E for ; Thu, 18 Apr 2019 17:57:53 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 07AEE6E185; Thu, 18 Apr 2019 17:57:49 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a01:7a0:2:106d:700::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id 970CB6E0CC; Thu, 18 Apr 2019 09:06:36 +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 1hH2zb-0001m0-4R; Thu, 18 Apr 2019 11:06:03 +0200 Message-Id: <20190418084253.234868907@linutronix.de> User-Agent: quilt/0.65 Date: Thu, 18 Apr 2019 10:41:21 +0200 From: Thomas Gleixner To: LKML Subject: [patch V2 02/29] stacktrace: Provide helpers for common stack trace operations References: <20190418084119.056416939@linutronix.de> MIME-Version: 1.0 X-Mailman-Approved-At: Thu, 18 Apr 2019 17:57:47 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mike Snitzer , David Airlie , Catalin Marinas , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, dm-devel@redhat.com, Alexander Potapenko , Christoph Lameter , Christoph Hellwig , Alasdair Kergon , Marek Szyprowski , 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 , Akinobu Mita , Steven Rostedt , Josef Bacik , Rodrigo Vivi , Mike Rapoport , Andy Lutomirski , Josh Poimboeuf , David Sterba , Dmitry Vyukov , Chris Mason , Pekka Enberg , iommu@lists.linux-foundation.org, Andrew Morton , Robin Murphy , linux-btrfs@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP All operations with stack traces are based on struct stack_trace. That's a horrible construct as the struct is a kitchen sink for input and output. Quite some usage sites embed it into their own data structures which creates weird indirections. There is absolutely no point in doing so. For all use cases a storage array and the number of valid stack trace entries in the array is sufficient. Provide helper functions which avoid the struct stack_trace indirection so the usage sites can be cleaned up. Signed-off-by: Thomas Gleixner --- include/linux/stacktrace.h | 27 +++++++ kernel/stacktrace.c | 160 ++++++++++++++++++++++++++++++++++++++++----- 2 files changed, 172 insertions(+), 15 deletions(-) --- a/include/linux/stacktrace.h +++ b/include/linux/stacktrace.h @@ -3,11 +3,26 @@ #define __LINUX_STACKTRACE_H #include +#include struct task_struct; struct pt_regs; #ifdef CONFIG_STACKTRACE +void stack_trace_print(unsigned long *trace, unsigned int nr_entries, + int spaces); +int stack_trace_snprint(char *buf, size_t size, unsigned long *entries, + unsigned int nr_entries, int spaces); +unsigned int stack_trace_save(unsigned long *store, unsigned int size, + unsigned int skipnr); +unsigned int stack_trace_save_tsk(struct task_struct *task, + unsigned long *store, unsigned int size, + unsigned int skipnr); +unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store, + unsigned int size, unsigned int skipnr); +unsigned int stack_trace_save_user(unsigned long *store, unsigned int size); + +/* Internal interfaces. Do not use in generic code */ struct stack_trace { unsigned int nr_entries, max_entries; unsigned long *entries; @@ -41,4 +56,16 @@ extern void save_stack_trace_user(struct # define save_stack_trace_tsk_reliable(tsk, trace) ({ -ENOSYS; }) #endif /* CONFIG_STACKTRACE */ +#if defined(CONFIG_STACKTRACE) && defined(CONFIG_HAVE_RELIABLE_STACKTRACE) +int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store, + unsigned int size); +#else +static inline int stack_trace_save_tsk_reliable(struct task_struct *tsk, + unsigned long *store, + unsigned int size) +{ + return -ENOSYS; +} +#endif + #endif /* __LINUX_STACKTRACE_H */ --- a/kernel/stacktrace.c +++ b/kernel/stacktrace.c @@ -11,35 +11,52 @@ #include #include -void print_stack_trace(struct stack_trace *trace, int spaces) +/** + * stack_trace_print - Print the entries in the stack trace + * @entries: Pointer to storage array + * @nr_entries: Number of entries in the storage array + * @spaces: Number of leading spaces to print + */ +void stack_trace_print(unsigned long *entries, unsigned int nr_entries, + int spaces) { - int i; + unsigned int i; - if (WARN_ON(!trace->entries)) + if (WARN_ON(!entries)) return; - for (i = 0; i < trace->nr_entries; i++) - printk("%*c%pS\n", 1 + spaces, ' ', (void *)trace->entries[i]); + for (i = 0; i < nr_entries; i++) + printk("%*c%pS\n", 1 + spaces, ' ', (void *)entries[i]); +} +EXPORT_SYMBOL_GPL(stack_trace_print); + +void print_stack_trace(struct stack_trace *trace, int spaces) +{ + stack_trace_print(trace->entries, trace->nr_entries, spaces); } EXPORT_SYMBOL_GPL(print_stack_trace); -int snprint_stack_trace(char *buf, size_t size, - struct stack_trace *trace, int spaces) +/** + * stack_trace_snprint - Print the entries in the stack trace into a buffer + * @buf: Pointer to the print buffer + * @size: Size of the print buffer + * @entries: Pointer to storage array + * @nr_entries: Number of entries in the storage array + * @spaces: Number of leading spaces to print + */ +int stack_trace_snprint(char *buf, size_t size, unsigned long *entries, + unsigned int nr_entries, int spaces) { - int i; - int generated; - int total = 0; + unsigned int generated, i, total = 0; - if (WARN_ON(!trace->entries)) + if (WARN_ON(!entries)) return 0; - for (i = 0; i < trace->nr_entries; i++) { + for (i = 0; i < nr_entries; i++) { generated = snprintf(buf, size, "%*c%pS\n", 1 + spaces, ' ', - (void *)trace->entries[i]); + (void *)entries[i]); total += generated; - - /* Assume that generated isn't a negative number */ if (generated >= size) { buf += size; size = 0; @@ -51,6 +68,14 @@ int snprint_stack_trace(char *buf, size_ return total; } +EXPORT_SYMBOL_GPL(stack_trace_snprint); + +int snprint_stack_trace(char *buf, size_t size, + struct stack_trace *trace, int spaces) +{ + return stack_trace_snprint(buf, size, trace->entries, + trace->nr_entries, spaces); +} EXPORT_SYMBOL_GPL(snprint_stack_trace); /* @@ -77,3 +102,108 @@ save_stack_trace_tsk_reliable(struct tas WARN_ONCE(1, KERN_INFO "save_stack_tsk_reliable() not implemented yet.\n"); return -ENOSYS; } + +/** + * stack_trace_save - Save a stack trace into a storage array + * @store: Pointer to storage array + * @size: Size of the storage array + * @skipnr: Number of entries to skip at the start of the stack trace + */ +unsigned int stack_trace_save(unsigned long *store, unsigned int size, + unsigned int skipnr) +{ + struct stack_trace trace = { + .entries = store, + .max_entries = size, + .skip = skipnr + 1, + }; + + save_stack_trace(&trace); + return trace.nr_entries; +} +EXPORT_SYMBOL_GPL(stack_trace_save); + +/** + * stack_trace_save_tsk - Save a task stack trace into a storage array + * @task: The task to examine + * @store: Pointer to storage array + * @size: Size of the storage array + * @skipnr: Number of entries to skip at the start of the stack trace + */ +unsigned int stack_trace_save_tsk(struct task_struct *task, + unsigned long *store, unsigned int size, + unsigned int skipnr) +{ + struct stack_trace trace = { + .entries = store, + .max_entries = size, + .skip = skipnr + 1, + }; + + save_stack_trace_tsk(task, &trace); + return trace.nr_entries; +} + +/** + * stack_trace_save_regs - Save a stack trace based on pt_regs into a storage array + * @regs: Pointer to pt_regs to examine + * @store: Pointer to storage array + * @size: Size of the storage array + * @skipnr: Number of entries to skip at the start of the stack trace + */ +unsigned int stack_trace_save_regs(struct pt_regs *regs, unsigned long *store, + unsigned int size, unsigned int skipnr) +{ + struct stack_trace trace = { + .entries = store, + .max_entries = size, + .skip = skipnr, + }; + + save_stack_trace_regs(regs, &trace); + return trace.nr_entries; +} + +#ifdef CONFIG_HAVE_RELIABLE_STACKTRACE +/** + * stack_trace_save_tsk_reliable - Save task stack with verification + * @tsk: Pointer to the task to examine + * @store: Pointer to storage array + * @size: Size of the storage array + * + * Returns: An error if it detects any unreliable features of the + * stack. Otherwise it guarantees that the stack trace is + * reliable and returns the number of entries stored. + * + * If the task is not 'current', the caller *must* ensure the task is inactive. + */ +int stack_trace_save_tsk_reliable(struct task_struct *tsk, unsigned long *store, + unsigned int size) +{ + struct stack_trace trace = { + .entries = store, + .max_entries = size, + }; + int ret = save_stack_trace_tsk_reliable(tsk, &trace); + + return ret ? ret : trace.nr_entries; +} +#endif + +#ifdef CONFIG_USER_STACKTRACE_SUPPORT +/** + * stack_trace_save_user - Save a user space stack trace into a storage array + * @store: Pointer to storage array + * @size: Size of the storage array + */ +unsigned int stack_trace_save_user(unsigned long *store, unsigned int size) +{ + struct stack_trace trace = { + .entries = store, + .max_entries = size, + }; + + save_stack_trace_user(&trace); + return trace.nr_entries; +} +#endif /* CONFIG_USER_STACKTRACE_SUPPORT */ From patchwork Thu Apr 18 08:41:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Gleixner X-Patchwork-Id: 10907757 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 4048913B5 for ; Thu, 18 Apr 2019 17:57:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 2505128D4E for ; Thu, 18 Apr 2019 17:57:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 12D3628D50; Thu, 18 Apr 2019 17:57:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.2 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 8B64128D4E for ; Thu, 18 Apr 2019 17:57:51 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id F2A6D6E184; Thu, 18 Apr 2019 17:57:48 +0000 (UTC) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a01:7a0:2:106d:700::1]) by gabe.freedesktop.org (Postfix) with ESMTPS id 971D06E0E6; Thu, 18 Apr 2019 09:06:36 +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 1hH305-0001rb-3d; Thu, 18 Apr 2019 11:06:33 +0200 Message-Id: <20190418084254.549410214@linutronix.de> User-Agent: quilt/0.65 Date: Thu, 18 Apr 2019 10:41:35 +0200 From: Thomas Gleixner To: LKML Subject: [patch V2 16/29] drm: Simplify stacktrace handling References: <20190418084119.056416939@linutronix.de> MIME-Version: 1.0 X-Mailman-Approved-At: Thu, 18 Apr 2019 17:57:47 +0000 X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mike Snitzer , David Airlie , Catalin Marinas , dri-devel@lists.freedesktop.org, linux-mm@kvack.org, dm-devel@redhat.com, Alexander Potapenko , Christoph Lameter , Christoph Hellwig , Alasdair Kergon , Marek Szyprowski , linux-arch@vger.kernel.org, x86@kernel.org, kasan-dev@googlegroups.com, David Rientjes , Andrey Ryabinin , Alexey Dobriyan , intel-gfx@lists.freedesktop.org, Johannes Thumshirn , Akinobu Mita , Josef Bacik , Mike Rapoport , Steven Rostedt , Andy Lutomirski , Rodrigo Vivi , David Sterba , Dmitry Vyukov , Josh Poimboeuf , Chris Mason , Pekka Enberg , iommu@lists.linux-foundation.org, Andrew Morton , Robin Murphy , linux-btrfs@vger.kernel.org Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" X-Virus-Scanned: ClamAV using ClamSMTP Replace the indirection through struct stack_trace by using the storage array based interfaces. The original code in all printing functions is really wrong. It allocates a storage array on stack which is unused because depot_fetch_stack() does not store anything in it. It overwrites the entries pointer in the stack_trace struct so it points to the depot storage. Signed-off-by: Thomas Gleixner Cc: intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen Cc: Maarten Lankhorst Cc: dri-devel@lists.freedesktop.org Cc: David Airlie Cc: Jani Nikula Cc: Daniel Vetter Cc: Rodrigo Vivi Acked-by: Daniel Vetter --- drivers/gpu/drm/drm_mm.c | 22 +++++++--------------- drivers/gpu/drm/i915/i915_vma.c | 11 ++++------- drivers/gpu/drm/i915/intel_runtime_pm.c | 21 +++++++-------------- 3 files changed, 18 insertions(+), 36 deletions(-) --- a/drivers/gpu/drm/drm_mm.c +++ b/drivers/gpu/drm/drm_mm.c @@ -106,22 +106,19 @@ static noinline void save_stack(struct drm_mm_node *node) { unsigned long entries[STACKDEPTH]; - struct stack_trace trace = { - .entries = entries, - .max_entries = STACKDEPTH, - .skip = 1 - }; + unsigned int n; - save_stack_trace(&trace); + n = stack_trace_save(entries, ARRAY_SIZE(entries), 1); /* May be called under spinlock, so avoid sleeping */ - node->stack = depot_save_stack(&trace, GFP_NOWAIT); + node->stack = stack_depot_save(entries, n, GFP_NOWAIT); } static void show_leaks(struct drm_mm *mm) { struct drm_mm_node *node; - unsigned long entries[STACKDEPTH]; + unsigned long *entries; + unsigned int nr_entries; char *buf; buf = kmalloc(BUFSZ, GFP_KERNEL); @@ -129,19 +126,14 @@ static void show_leaks(struct drm_mm *mm return; list_for_each_entry(node, drm_mm_nodes(mm), node_list) { - struct stack_trace trace = { - .entries = entries, - .max_entries = STACKDEPTH - }; - if (!node->stack) { DRM_ERROR("node [%08llx + %08llx]: unknown owner\n", node->start, node->size); continue; } - depot_fetch_stack(node->stack, &trace); - snprint_stack_trace(buf, BUFSZ, &trace, 0); + nr_entries = stack_depot_fetch(node->stack, &entries); + stack_trace_snprint(buf, BUFSZ, entries, nr_entries, 0); DRM_ERROR("node [%08llx + %08llx]: inserted at\n%s", node->start, node->size, buf); } --- a/drivers/gpu/drm/i915/i915_vma.c +++ b/drivers/gpu/drm/i915/i915_vma.c @@ -36,11 +36,8 @@ static void vma_print_allocator(struct i915_vma *vma, const char *reason) { - unsigned long entries[12]; - struct stack_trace trace = { - .entries = entries, - .max_entries = ARRAY_SIZE(entries), - }; + unsigned long *entries; + unsigned int nr_entries; char buf[512]; if (!vma->node.stack) { @@ -49,8 +46,8 @@ static void vma_print_allocator(struct i return; } - depot_fetch_stack(vma->node.stack, &trace); - snprint_stack_trace(buf, sizeof(buf), &trace, 0); + nr_entries = stack_depot_fetch(vma->node.stack, &entries); + stack_trace_snprint(buf, sizeof(buf), entries, nr_entries, 0); DRM_DEBUG_DRIVER("vma.node [%08llx + %08llx] %s: inserted at %s\n", vma->node.start, vma->node.size, reason, buf); } --- a/drivers/gpu/drm/i915/intel_runtime_pm.c +++ b/drivers/gpu/drm/i915/intel_runtime_pm.c @@ -60,27 +60,20 @@ static noinline depot_stack_handle_t __save_depot_stack(void) { unsigned long entries[STACKDEPTH]; - struct stack_trace trace = { - .entries = entries, - .max_entries = ARRAY_SIZE(entries), - .skip = 1, - }; + unsigned int n; - save_stack_trace(&trace); - return depot_save_stack(&trace, GFP_NOWAIT | __GFP_NOWARN); + n = stack_trace_save(entries, ARRAY_SIZE(entries), 1); + return stack_depot_save(entries, n, GFP_NOWAIT | __GFP_NOWARN); } static void __print_depot_stack(depot_stack_handle_t stack, char *buf, int sz, int indent) { - unsigned long entries[STACKDEPTH]; - struct stack_trace trace = { - .entries = entries, - .max_entries = ARRAY_SIZE(entries), - }; + unsigned long *entries; + unsigned int nr_entries; - depot_fetch_stack(stack, &trace); - snprint_stack_trace(buf, sz, &trace, indent); + nr_entries = stack_depot_fetch(stack, &entries); + stack_trace_snprint(buf, sz, entries, nr_entries, indent); } static void init_intel_runtime_pm_wakeref(struct drm_i915_private *i915)