From nobody Fri Feb 13 01:41:21 2026 Received: from szxga05-in.huawei.com (szxga05-in.huawei.com [45.249.212.191]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D0D3B8C1D; Tue, 4 Jun 2024 03:49:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.191 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717472959; cv=none; b=o0s4/2qsjnw8zKlo7jsPo2hoaecOhG9bYnfX9hJfyUlG0vEBD1v/g04U2FOvlV4ivR3QjZ/5XP7l5mffD/7aODS8TzjpAwpj/+lC8kO3qIxrX5F4kg/AR3ZjzXphITkfTJDpMfwqUMk3YKdlnyEKunxirGq4HW54zTzlGAZ9rGE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717472959; c=relaxed/simple; bh=32h6BoyXtdf0b9iqsX+Zjc0t7Jt5CWu7Fk7Jfg+ZRuk=; h=From:To:CC:Subject:Date:Message-ID:MIME-Version:Content-Type; b=ucK7jxAmw6auVvvPvizHHUkWwRiLWI6dJ4gGvKrmzCCns+/Z2ohfEm+JC6ELSW/efqF4KDrbdatideoh2e6SE6uNWnd4j8023mpU2MR6ZGRHgQto/HFzjjiNFeXVuAWh4SsjS8o9yOdvQq3OlVnLAezya63/did1ByhAvYSroMw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=45.249.212.191 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga05-in.huawei.com (SkyGuard) with ESMTP id 4Vtc3y5hFkz1HCrM; Tue, 4 Jun 2024 11:47:26 +0800 (CST) Received: from kwepemi500008.china.huawei.com (unknown [7.221.188.139]) by mail.maildlp.com (Postfix) with ESMTPS id B93F6140230; Tue, 4 Jun 2024 11:49:12 +0800 (CST) Received: from huawei.com (10.67.174.55) by kwepemi500008.china.huawei.com (7.221.188.139) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.39; Tue, 4 Jun 2024 11:49:11 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v2] riscv: stacktrace: Add USER_STACKTRACE support Date: Tue, 4 Jun 2024 03:47:29 +0000 Message-ID: <20240604034729.841930-1-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To kwepemi500008.china.huawei.com (7.221.188.139) Content-Type: text/plain; charset="utf-8" Currently, userstacktrace is unsupported for riscv. So use the perf_callchain_user() code as blueprint to implement the arch_stack_walk_user() which add userstacktrace support on riscv. Meanwhile, we can use arch_stack_walk_user() to simplify the implementation of perf_callchain_user(). Signed-off-by: Jinjie Ruan Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202406012109.PDAjXm2i-lkp@int= el.com/ --- v2: - Fix the cocci warning, !A || A && B is equivalent to !A || B. --- arch/riscv/Kconfig | 1 + arch/riscv/kernel/perf_callchain.c | 46 ++---------------------------- arch/riscv/kernel/stacktrace.c | 43 ++++++++++++++++++++++++++++ 3 files changed, 47 insertions(+), 43 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 0525ee2d63c7..6ed96d935b8f 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -193,6 +193,7 @@ config RISCV select THREAD_INFO_IN_TASK select TRACE_IRQFLAGS_SUPPORT select UACCESS_MEMCPY if !MMU + select USER_STACKTRACE_SUPPORT select ZONE_DMA32 if 64BIT =20 config CLANG_SUPPORTS_DYNAMIC_FTRACE diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_ca= llchain.c index 3348a61de7d9..c7468af77c66 100644 --- a/arch/riscv/kernel/perf_callchain.c +++ b/arch/riscv/kernel/perf_callchain.c @@ -6,37 +6,9 @@ =20 #include =20 -/* - * Get the return address for a single stackframe and return a pointer to = the - * next frame tail. - */ -static unsigned long user_backtrace(struct perf_callchain_entry_ctx *entry, - unsigned long fp, unsigned long reg_ra) +static bool fill_callchain(void *entry, unsigned long pc) { - struct stackframe buftail; - unsigned long ra =3D 0; - unsigned long __user *user_frame_tail =3D - (unsigned long __user *)(fp - sizeof(struct stackframe)); - - /* Check accessibility of one struct frame_tail beyond */ - if (!access_ok(user_frame_tail, sizeof(buftail))) - return 0; - if (__copy_from_user_inatomic(&buftail, user_frame_tail, - sizeof(buftail))) - return 0; - - if (reg_ra !=3D 0) - ra =3D reg_ra; - else - ra =3D buftail.ra; - - fp =3D buftail.fp; - if (ra !=3D 0) - perf_callchain_store(entry, ra); - else - return 0; - - return fp; + return perf_callchain_store(entry, pc) =3D=3D 0; } =20 /* @@ -56,19 +28,7 @@ static unsigned long user_backtrace(struct perf_callchai= n_entry_ctx *entry, void perf_callchain_user(struct perf_callchain_entry_ctx *entry, struct pt_regs *regs) { - unsigned long fp =3D 0; - - fp =3D regs->s0; - perf_callchain_store(entry, regs->epc); - - fp =3D user_backtrace(entry, fp, regs->ra); - while (fp && !(fp & 0x3) && entry->nr < entry->max_stack) - fp =3D user_backtrace(entry, fp, 0); -} - -static bool fill_callchain(void *entry, unsigned long pc) -{ - return perf_callchain_store(entry, pc) =3D=3D 0; + arch_stack_walk_user(fill_callchain, entry, regs); } =20 void perf_callchain_kernel(struct perf_callchain_entry_ctx *entry, diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c index 528ec7cc9a62..9685a2baa5d9 100644 --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -161,3 +161,46 @@ noinline void arch_stack_walk(stack_trace_consume_fn c= onsume_entry, void *cookie { walk_stackframe(task, regs, consume_entry, cookie); } + +/* + * Get the return address for a single stackframe and return a pointer to = the + * next frame tail. + */ +static unsigned long unwind_user_frame(stack_trace_consume_fn consume_entr= y, + void *cookie, unsigned long fp, + unsigned long reg_ra) +{ + struct stackframe buftail; + unsigned long ra =3D 0; + unsigned long __user *user_frame_tail =3D + (unsigned long __user *)(fp - sizeof(struct stackframe)); + + /* Check accessibility of one struct frame_tail beyond */ + if (!access_ok(user_frame_tail, sizeof(buftail))) + return 0; + if (__copy_from_user_inatomic(&buftail, user_frame_tail, + sizeof(buftail))) + return 0; + + ra =3D reg_ra ? : buftail.ra; + + fp =3D buftail.fp; + if (!ra || !consume_entry(cookie, ra)) + return 0; + + return fp; +} + +void arch_stack_walk_user(stack_trace_consume_fn consume_entry, void *cook= ie, + const struct pt_regs *regs) +{ + unsigned long fp =3D 0; + + fp =3D regs->s0; + if (!consume_entry(cookie, regs->epc)) + return; + + fp =3D unwind_user_frame(consume_entry, cookie, fp, regs->ra); + while (fp && !(fp & 0x3)) + fp =3D unwind_user_frame(consume_entry, cookie, fp, 0); +} --=20 2.34.1