From nobody Mon Feb 9 02:55:19 2026 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) (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 ADC527494; Mon, 8 Jul 2024 03:25:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.187 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720409106; cv=none; b=ODJWoK9qi7KoaBcsRENKWuydC50HuD1NMk6jtOJBIJbXd46oBJSzmQVXVkj414dQ+0WJPSq7rxNXgtynPFu2UmVMXxaXxssc0zv3wwT6IJXB93Azle7E6mUZVxBeY5E1mMSS1dTTGPL2BgFliBKodc/H0Vl3twpnaYY9EWIFumg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720409106; c=relaxed/simple; bh=cUnV2O6AKyz5UnbKsyl6R+zngzKKJAHcApc1Y+rigdo=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=vFbDMg17sPZpF507jOdBPMKGxLW+WCRmiSFxUvDbWTngMuvpiQ4tbEe32tlW3nAP0uCW2SURuh2cCTGS8SrHUbe0xyxxsjvZ7Xbr4eXetyjsQ0MEGHDFJiaWIBxkQZ64cmxofekK/Eo3Bby4bfo5qG8w8Ylgee7/NzOLNbbEJ4k= 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=45.249.212.187 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 [172.19.162.254]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4WHTs85hb7zxVB2; Mon, 8 Jul 2024 11:20:28 +0800 (CST) Received: from kwepemi100008.china.huawei.com (unknown [7.221.188.57]) by mail.maildlp.com (Postfix) with ESMTPS id 6ECFF1800C7; Mon, 8 Jul 2024 11:24:46 +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; Mon, 8 Jul 2024 11:24:45 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v3 1/2] riscv: Fix fp alignment bug in perf_callchain_user() Date: Mon, 8 Jul 2024 11:28:46 +0800 Message-ID: <20240708032847.2998158-2-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240708032847.2998158-1-ruanjinjie@huawei.com> References: <20240708032847.2998158-1-ruanjinjie@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemi100008.china.huawei.com (7.221.188.57) The standard RISC-V calling convention said: "The stack grows downward and the stack pointer is always kept 16-byte aligned". So perf_callchain_user() should check whether 16-byte aligned for fp. Link: https://riscv.org/wp-content/uploads/2015/01/riscv-calling.pdf Fixes: dbeb90b0c1eb ("riscv: Add perf callchain support") Signed-off-by: Jinjie Ruan Cc: Bj=C3=B6rn T=C3=B6pel --- arch/riscv/kernel/perf_callchain.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/kernel/perf_callchain.c b/arch/riscv/kernel/perf_ca= llchain.c index 3348a61de7d9..2932791e9388 100644 --- a/arch/riscv/kernel/perf_callchain.c +++ b/arch/riscv/kernel/perf_callchain.c @@ -62,7 +62,7 @@ void perf_callchain_user(struct perf_callchain_entry_ctx = *entry, perf_callchain_store(entry, regs->epc); =20 fp =3D user_backtrace(entry, fp, regs->ra); - while (fp && !(fp & 0x3) && entry->nr < entry->max_stack) + while (fp && !(fp & 0x7) && entry->nr < entry->max_stack) fp =3D user_backtrace(entry, fp, 0); } =20 --=20 2.34.1 From nobody Mon Feb 9 02:55:19 2026 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) (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 222A87494; Mon, 8 Jul 2024 03:25:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.255 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720409121; cv=none; b=NeBf7Zmz5D7LKWDnoVJfYhaRgbuO1vs8qU+cMZbIGudxtvydGFe6jbWamoZz1XPuB6ERq5ZR2T0QVQDpNRoXnM0uJmeI98BZpG/9UhdwmEaQo0wVRX6qDhAed9gIlpYfkG7xN6COguYxYWay1oZ5ATie+WpkjP2QLBOBcJDeGzs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720409121; c=relaxed/simple; bh=dkU4z013Z+G02C6TKWPigEwbImuXYJcAukS3s4VQPdU=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=YqmNaVYG+21+zodrZ4A+l/zis+OrjswacQoJjokzuthTKbQqxOTns9yu97mHxOKBWvoDoAyscBEl4Ls6ZLpYVRzSsPvpyedmYzc6gL8H385safdn11s5BIps7vHihED/stsp8/V8XR9VmqNDNC/loMJSimeX/JWKBTPaeXtQ8qo= 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=45.249.212.255 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 [172.19.162.254]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4WHTsK05h6z1T5Y1; Mon, 8 Jul 2024 11:20:37 +0800 (CST) Received: from kwepemi100008.china.huawei.com (unknown [7.221.188.57]) by mail.maildlp.com (Postfix) with ESMTPS id 7CDA31800C0; Mon, 8 Jul 2024 11:25:01 +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; Mon, 8 Jul 2024 11:24:46 +0800 From: Jinjie Ruan To: , , , , , , , , , , , , , , , , , , CC: Subject: [PATCH v3 2/2] riscv: stacktrace: Add USER_STACKTRACE support Date: Mon, 8 Jul 2024 11:28:47 +0800 Message-ID: <20240708032847.2998158-3-ruanjinjie@huawei.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240708032847.2998158-1-ruanjinjie@huawei.com> References: <20240708032847.2998158-1-ruanjinjie@huawei.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemi100008.china.huawei.com (7.221.188.57) 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(). 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 ...... bash-178 [000] ...1. 97.968395: sched_process_fork: com= m=3Dbash pid=3D178 child_comm=3Dbash child_pid=3D231 bash-178 [000] ...1. 97.970075: =3D> /lib/libc.so.6[+0xb5090] Also a simple perf test is ok as below: # perf record -e cpu-clock --call-graph fp top # perf report --call-graph ..... [[31m 66.54%[[m 0.00% top [kernel.kallsyms] [k] ret_= from_exception | ---ret_from_exception | |--[[31m58.97%[[m--do_trap_ecall_u | | | |--[[31m17.34%[[m--__riscv_sys_read | | ksys_read | | | | | --[[31m16.88%[[m--vfs_read | | | | | |--[[31m10.90%[[m--seq_read Signed-off-by: Jinjie Ruan Tested-by: Jinjie Ruan Cc: Bj=C3=B6rn T=C3=B6pel --- v3: - Remove the LTP message as Bj=C3=B6rn suggested. - Keep fp 16-bytes aligned in arch_stack_walk_user(). - Add the test info. 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 3b44e7b51436..46121dbcf750 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -194,6 +194,7 @@ 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 2932791e9388..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 & 0x7) && 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 0d3f00eb0bae..5480cc11b523 100644 --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -161,3 +161,46 @@ noinline noinstr void arch_stack_walk(stack_trace_cons= ume_fn consume_entry, void { 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 & 0x7)) + fp =3D unwind_user_frame(consume_entry, cookie, fp, 0); +} --=20 2.34.1