From patchwork Tue Aug 4 07:44:07 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: AKASHI Takahiro X-Patchwork-Id: 6934741 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 489C99F373 for ; Tue, 4 Aug 2015 07:47:48 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7D865205CB for ; Tue, 4 Aug 2015 07:47:43 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id ACF5A205E3 for ; Tue, 4 Aug 2015 07:47:41 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZMWuf-0002hs-1C; Tue, 04 Aug 2015 07:45:29 +0000 Received: from mail-pa0-f47.google.com ([209.85.220.47]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1ZMWuV-0001Od-8H for linux-arm-kernel@lists.infradead.org; Tue, 04 Aug 2015 07:45:21 +0000 Received: by pacgq8 with SMTP id gq8so1934585pac.3 for ; Tue, 04 Aug 2015 00:44:58 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=m3Pzj5KTf0M+gxv1EzI0vFNBNJugJwKB9nkoB8u5p20=; b=JolydKV/NQaeiGemSupSJQsGac1F0SHoBMDEROaHw+cOM/dyOtBBmXryG7JlPZYtn6 5p9w+S+S9BfP+iKxeAEXj8OFEMrWz6a8y+kbkJvJxxaUT/XznlOw6SyJWiuH+XfL1bs1 sLYXS5s8RYnigoIa/buGXQh6Hy23dISP1fMsn+rmnVLGLKoiQAC9wkudkhNPQ9JAGzSB VsbdtT9w/q0sahsA5LR6/nQfS3ie0CMkLAtyIzE86hwHPxp6Wz4cluu+WFGD258Ylo3w pgOVx665oWVJbepbdz5IwVa+F+cZ7asq7TeU096B8bgIJ0wirwyrd9cgk9ZtEbq/p4eJ jiSw== X-Gm-Message-State: ALoCoQnTztxuA3Ppqz8x5ALvniOiW0liAUgNIdEc6ckKKgXJUWv8aRzISENakTuEfLGi+AzPFV05 X-Received: by 10.68.169.69 with SMTP id ac5mr5123685pbc.14.1438674298524; Tue, 04 Aug 2015 00:44:58 -0700 (PDT) Received: from localhost.localdomain (61-205-6-81m5.grp1.mineo.jp. [61.205.6.81]) by smtp.googlemail.com with ESMTPSA id bd5sm287869pbb.85.2015.08.04.00.44.53 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 04 Aug 2015 00:44:57 -0700 (PDT) From: AKASHI Takahiro To: catalin.marinas@arm.com, will.deacon@arm.com, rostedt@goodmis.org Subject: [RFC v2 2/4] arm64: ftrace: add arch-specific stack tracer Date: Tue, 4 Aug 2015 16:44:07 +0900 Message-Id: <1438674249-3447-3-git-send-email-takahiro.akashi@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1438674249-3447-1-git-send-email-takahiro.akashi@linaro.org> References: <1438674249-3447-1-git-send-email-takahiro.akashi@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150804_004519_476882_BE67D735 X-CRM114-Status: GOOD ( 20.37 ) X-Spam-Score: -2.6 (--) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: jungseoklee85@gmail.com, linux-kernel@vger.kernel.org, AKASHI Takahiro , broonie@kernel.org, david.griego@linaro.org, olof@lixom.net, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch uses walk_stackframe(), instead of slurping stack contents as orignal check_stack() does, to identify each stack frame. return_to_handler() is handled in a special way because it is not a function, but invoked via function graph tracer by faking a saved lr register on stack. Signed-off-by: AKASHI Takahiro --- arch/arm64/include/asm/ftrace.h | 2 ++ arch/arm64/kernel/ftrace.c | 37 +++++++++++++++++++++++++ arch/arm64/kernel/stacktrace.c | 58 +++++++++++++++++++++++++++++++++++++-- 3 files changed, 95 insertions(+), 2 deletions(-) diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h index 2b43e20..b7d597c 100644 --- a/arch/arm64/include/asm/ftrace.h +++ b/arch/arm64/include/asm/ftrace.h @@ -29,6 +29,8 @@ struct dyn_arch_ftrace { extern unsigned long ftrace_graph_call; +extern void return_to_handler(void); + static inline unsigned long ftrace_call_adjust(unsigned long addr) { /* diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index c851be7..d812870 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -176,3 +176,40 @@ int ftrace_disable_ftrace_graph_caller(void) } #endif /* CONFIG_DYNAMIC_FTRACE */ #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + +#ifdef CONFIG_STACK_TRACER +#define stack_top(fp) (((fp) & ~(THREAD_SIZE-1)) + THREAD_SIZE) +#define stack_index(fp) (stack_top((fp)) - (fp)) + +extern struct stack_trace max_stack_trace; +extern void save_stack_trace_index(struct stack_trace *trace); + +void arch_check_stack(unsigned long ip, unsigned long *stack, + unsigned long *max_size, int *tracer_size) +{ + int i, j; + + max_stack_trace.skip = 0; + save_stack_trace_index(&max_stack_trace); + max_stack_trace.nr_entries--; /* for '-1' entry */ + + /* Skip over the overhead of the stack tracer itself */ + for (i = 0; i < max_stack_trace.nr_entries; i++) { + if ((max_stack_trace.entries[i] + FTRACE_STACK_FRAME_OFFSET) + == ip) + break; + } + + if (unlikely(!*tracer_size)) { + *tracer_size = stack_index((unsigned long)stack) + - max_stack_trace.index[i]; + *max_size -= *tracer_size; + } + + max_stack_trace.nr_entries -= i; + for (j = 0; j < max_stack_trace.nr_entries; j++) { + max_stack_trace.index[j] = max_stack_trace.index[j + i]; + max_stack_trace.entries[j] = max_stack_trace.entries[j + i]; + } +} +#endif /* CONFIG_STACK_TRACER */ diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index bc0689a..496ab0f 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -17,12 +17,15 @@ */ #include #include +#include #include #include #include #include +#define S_FRAME_SIZE sizeof(struct pt_regs) /* asm-offsets.h */ + /* * AArch64 PCS assigns the frame pointer to x29. * @@ -78,9 +81,29 @@ struct stack_trace_data { struct stack_trace *trace; unsigned int no_sched_functions; unsigned int skip; +#ifdef CONFIG_STACK_TRACER + int ftracer; + int ret_stack_index; +#endif }; -static int save_trace(struct stackframe *frame, void *d) +#ifdef CONFIG_STACK_TRACER +static void notrace arm64_stack_index(struct stackframe *frame, + struct stack_trace_data *data) +{ + struct stack_trace *trace = data->trace; + unsigned long top; + unsigned int x = trace->nr_entries; + + top = (frame->fp & ~(THREAD_SIZE-1)) + THREAD_SIZE; + trace->index[x] = top - frame->fp; + /* should not go beyond this frame */ + if (trace->index[x] == THREAD_SIZE) + trace->index[x] = 0; +} +#endif /* CONFIG_STACK_TRACER */ + +static int notrace save_trace(struct stackframe *frame, void *d) { struct stack_trace_data *data = d; struct stack_trace *trace = data->trace; @@ -93,7 +116,13 @@ static int save_trace(struct stackframe *frame, void *d) return 0; } - trace->entries[trace->nr_entries++] = addr; + trace->entries[trace->nr_entries] = addr; +#ifdef CONFIG_STACK_TRACER + if (data->ftracer) { + arm64_stack_index(frame, data); + } +#endif + trace->nr_entries++; return trace->nr_entries >= trace->max_entries; } @@ -105,6 +134,9 @@ void save_stack_trace_tsk(struct task_struct *tsk, struct stack_trace *trace) data.trace = trace; data.skip = trace->skip; +#ifdef CONFIG_STACK_TRACER + data.ftracer = 0; +#endif if (tsk != current) { data.no_sched_functions = 1; @@ -128,4 +160,26 @@ void save_stack_trace(struct stack_trace *trace) save_stack_trace_tsk(current, trace); } EXPORT_SYMBOL_GPL(save_stack_trace); + +#ifdef CONFIG_STACK_TRACER +void notrace save_stack_trace_index(struct stack_trace *trace) +{ + struct stack_trace_data data; + struct stackframe frame; + + data.trace = trace; + data.skip = trace->skip; + data.ftracer = 1; + data.ret_stack_index = current->curr_ret_stack; + + data.no_sched_functions = 0; + frame.fp = (unsigned long)__builtin_frame_address(0); + frame.sp = current_stack_pointer; + frame.pc = (unsigned long)save_stack_trace_index; + + walk_stackframe(&frame, save_trace, &data); + if (trace->nr_entries < trace->max_entries) + trace->entries[trace->nr_entries++] = ULONG_MAX; +} +#endif /* CONFIG_STACK_TRACER */ #endif