From patchwork Tue Jul 30 02:15:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jinjie Ruan X-Patchwork-Id: 13746260 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5615EC3DA4A for ; Tue, 30 Jul 2024 02:10:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:CC:To:From: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Owner; bh=FAgATJ5ZgzVhLbeWEc2x+OHmn78XwZtJcuqZ5DY4948=; b=E9rEjGsQ9B2+hlJdutzemHH1sc ag8On+eNmd2MQlDE0C73GxL3jKQNHBUMmpxUnZslfrBmxrQDPT5DRWBYvl4/7lQagODRMF+8f9mXI u5jvPs9Ywe+0BRBgispKsIbXvp0Yo0AHwdOeK3m3jvltV+H/Zcjj+RsKWMEZRg0F+rxgjmgIY/urK Ypqis1qH5lN45Q7DNw1J0qi4g40JNIHGVVnaPELJCCQ1rtZ5JjVFMG3e7yJL3tLS+W2Ez0Pn0F6dH DVlSgco1EMaBAcdo2Act6WMiZA4QE15vKzF0wARtwLgl3hHT0kAXR4OrNfFv2qdkXGOEv9WhkTnSx 6bqML+Vg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sYcJh-0000000DIxf-21S8; Tue, 30 Jul 2024 02:10:21 +0000 Received: from szxga05-in.huawei.com ([45.249.212.191]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sYcJF-0000000DIsw-0WBo for linux-arm-kernel@lists.infradead.org; Tue, 30 Jul 2024 02:09:55 +0000 Received: from mail.maildlp.com (unknown [172.19.88.163]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4WXz8F3dxkz28fvb; Tue, 30 Jul 2024 10:05:17 +0800 (CST) Received: from kwepemi100008.china.huawei.com (unknown [7.221.188.57]) by mail.maildlp.com (Postfix) with ESMTPS id 82149180043; Tue, 30 Jul 2024 10:09:49 +0800 (CST) Received: from huawei.com (10.90.53.73) by kwepemi100008.china.huawei.com (7.221.188.57) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Tue, 30 Jul 2024 10:09:48 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v2] ARM: stacktrace: Add USER_STACKTRACE support Date: Tue, 30 Jul 2024 10:15:32 +0800 Message-ID: <20240730021532.1752582-1-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Originating-IP: [10.90.53.73] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemi100008.china.huawei.com (7.221.188.57) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240729_190953_571043_FD8A5C11 X-CRM114-Status: GOOD ( 19.58 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Currently, userstacktrace is unsupported for ARM. So use the perf_callchain_user() code as blueprint to implement the arch_stack_walk_user() which add userstacktrace support on ARM. Meanwhile, we can use arch_stack_walk_user() to simplify the implementation of perf_callchain_user(). A ftrace test case is shown as below: # cd /sys/kernel/debug/tracing # echo 1 > options/userstacktrace # echo 1 > options/sym-userobj # echo 1 > events/sched/sched_process_fork/enable # cat trace ...... sh-100 [000] ..... 51.779261: sched_process_fork: comm=sh pid=100 child_comm=sh child_pid=108 sh-100 [000] ..... 51.779285: => /lib/libc.so.6[+0xb3c8c] => /bin/busybox[+0xffb901f1] Also a simple perf test is ok as below: # perf record -e cpu-clock --call-graph fp top # perf report --call-graph ..... [[31m 65.00%[[m 0.00% top [kernel.kallsyms] [k] __ret_fast_syscall | ---__ret_fast_syscall | |--[[31m30.00%[[m--__se_sys_getdents64 | iterate_dir | | | |--[[31m25.00%[[m--proc_pid_readdir Signed-off-by: Jinjie Ruan --- v2: - Update the wrong patch title. - Take off the merged bugfix patch. - Remove the Tested-by. --- arch/arm/Kconfig | 1 + arch/arm/kernel/perf_callchain.c | 70 +++----------------------------- arch/arm/kernel/stacktrace.c | 65 +++++++++++++++++++++++++++++ 3 files changed, 72 insertions(+), 64 deletions(-) diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 54b2bb817a7f..eb9a587935ef 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -152,6 +152,7 @@ config ARM select HAVE_ARCH_VMAP_STACK if MMU && ARM_HAS_GROUP_RELOCS select TRACE_IRQFLAGS_SUPPORT if !CPU_V7M select USE_OF if !(ARCH_FOOTBRIDGE || ARCH_RPC || ARCH_SA1100) + select USER_STACKTRACE_SUPPORT # Above selects are sorted alphabetically; please add new ones # according to that. Thanks. help diff --git a/arch/arm/kernel/perf_callchain.c b/arch/arm/kernel/perf_callchain.c index 1d230ac9d0eb..cdb7aa31c6ec 100644 --- a/arch/arm/kernel/perf_callchain.c +++ b/arch/arm/kernel/perf_callchain.c @@ -12,70 +12,6 @@ #include -/* - * The registers we're interested in are at the end of the variable - * length saved register structure. The fp points at the end of this - * structure so the address of this struct is: - * (struct frame_tail *)(xxx->fp)-1 - * - * This code has been adapted from the ARM OProfile support. - */ -struct frame_tail { - struct frame_tail __user *fp; - unsigned long sp; - unsigned long lr; -} __attribute__((packed)); - -/* - * Get the return address for a single stackframe and return a pointer to the - * next frame tail. - */ -static struct frame_tail __user * -user_backtrace(struct frame_tail __user *tail, - struct perf_callchain_entry_ctx *entry) -{ - struct frame_tail buftail; - unsigned long err; - - if (!access_ok(tail, sizeof(buftail))) - return NULL; - - pagefault_disable(); - err = __copy_from_user_inatomic(&buftail, tail, sizeof(buftail)); - pagefault_enable(); - - if (err) - return NULL; - - perf_callchain_store(entry, buftail.lr); - - /* - * Frame pointers should strictly progress back up the stack - * (towards higher addresses). - */ - if (tail + 1 >= buftail.fp) - return NULL; - - return buftail.fp - 1; -} - -void -perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) -{ - struct frame_tail __user *tail; - - perf_callchain_store(entry, regs->ARM_pc); - - if (!current->mm) - return; - - tail = (struct frame_tail __user *)regs->ARM_fp - 1; - - while ((entry->nr < entry->max_stack) && - tail && !((unsigned long)tail & 0x3)) - tail = user_backtrace(tail, entry); -} - /* * Gets called by walk_stackframe() for every stackframe. This will be called * whist unwinding the stackframe and is like a subroutine return so we use @@ -88,6 +24,12 @@ callchain_trace(void *data, unsigned long pc) return perf_callchain_store(entry, pc) == 0; } +void +perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) +{ + arch_stack_walk_user(callchain_trace, entry, regs); +} + void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { diff --git a/arch/arm/kernel/stacktrace.c b/arch/arm/kernel/stacktrace.c index 620aa82e3bdd..b744792755b5 100644 --- a/arch/arm/kernel/stacktrace.c +++ b/arch/arm/kernel/stacktrace.c @@ -194,4 +194,69 @@ void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, walk_stackframe(&frame, consume_entry, cookie); } + +/* + * The registers we're interested in are at the end of the variable + * length saved register structure. The fp points at the end of this + * structure so the address of this struct is: + * (struct frame_tail *)(xxx->fp)-1 + * + * This code has been adapted from the ARM OProfile support. + */ +struct frame_tail { + struct frame_tail __user *fp; + unsigned long sp; + unsigned long lr; +} __packed; + +/* + * Get the return address for a single stackframe and return a pointer to the + * next frame tail. + */ +static struct frame_tail __user * +unwind_user_frame(struct frame_tail __user *tail, void *cookie, + stack_trace_consume_fn consume_entry) +{ + struct frame_tail buftail; + unsigned long err; + + if (!access_ok(tail, sizeof(buftail))) + return NULL; + + pagefault_disable(); + err = __copy_from_user_inatomic(&buftail, tail, sizeof(buftail)); + pagefault_enable(); + + if (err) + return NULL; + + if (!consume_entry(cookie, buftail.lr)) + return NULL; + + /* + * Frame pointers should strictly progress back up the stack + * (towards higher addresses). + */ + if (tail + 1 >= buftail.fp) + return NULL; + + return buftail.fp - 1; +} + +void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cookie, + const struct pt_regs *regs) +{ + struct frame_tail __user *tail; + + if (!consume_entry(cookie, regs->ARM_pc)) + return; + + if (!current->mm) + return; + + tail = (struct frame_tail __user *)regs->ARM_fp - 1; + + while (tail && !((unsigned long)tail & 0x3)) + tail = unwind_user_frame(tail, cookie, consume_entry); +} #endif