From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 96E9E252901 for ; Wed, 19 Mar 2025 11:58:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742385492; cv=none; b=PZ86sPmikYICCnMPafIQ0FdMx+wAkXECICaAp9e9hdU20bjNRPk+mCl0azlFpJHmq8HeI0wnefnlpfgLDC9idxNSlnnTIzZLZGISRjP/QHjDVf4v7Yc002FyMUsSfO7CFkWekSSNKt95NupROPi1UvejtUPmsnuNLu8jqGV1aqg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742385492; c=relaxed/simple; bh=wT6b6JnWz/fZ6OTXLxUIco8hyKOpMzJo6iTceJDVhZQ=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=VttNfUDBHydnbhBcQFGIeJ9ma4hVQbMPSSJifFs+IDziXDeLoKqXqxYjQVt74c+5U4Xiz/knsCuuihxUSA3Fg15zMf3AaFO6tOZbB8/Z1Nao1VooRaxYL8QqxG4NH/B2ZsxJx7bqmcR6v/FlNG2mdHoXvnGbaZiQOBv/+mUaCWg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=kXVcDQSJ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="kXVcDQSJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3C8EC4CEE9; Wed, 19 Mar 2025 11:58:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742385492; bh=wT6b6JnWz/fZ6OTXLxUIco8hyKOpMzJo6iTceJDVhZQ=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=kXVcDQSJukbMqoHH5olltjcObX2kIeDnJjaPXabuYJWKdyUKz6P5icT3K0fA26LTN I7UWgsdKW22m46wCrUramR8oqz0BSkwCY2ze74PWDnVo8c0yG1/VVnPMTkFdV/RSZo bMmwwFDT0+ulJvzv1+UrwTBjKghCvNF8xMFTFVFIESN2rqWUwhtBFuToHOj0KHs6xA TciW1G+KufAFAFVqizOPPN8NU/K1IR6LVVIg0hnPipXmr8ZIjkT3qTrXvaAlUVIcRQ KODQzuiUNBx8fRimAm9vTd24Vco2KUqOlnH2kjBzV6WHl/Iy/TLHkscAQ6OdxWVLAg x07o9x8DZj3qg== Date: Wed, 19 Mar 2025 20:58:07 +0900 From: Masami Hiramatsu (Google) To: Pu Lehui Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Palmer Dabbelt , Alexandre Ghiti , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , "Masami Hiramatsu (Google)" , "Steven Rostedt (Google)" , Naresh Kamboju , Pu Lehui Subject: Re: [PATCH v2 2/2] riscv: fgraph: Fix stack layout to match __arch_ftrace_regs argument of ftrace_return_to_handler Message-Id: <20250319205807.9b20737122775a81cf4e3a9e@kernel.org> In-Reply-To: <20250317031214.4138436-2-pulehui@huaweicloud.com> References: <20250317031214.4138436-1-pulehui@huaweicloud.com> <20250317031214.4138436-2-pulehui@huaweicloud.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) 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: 8bit On Mon, 17 Mar 2025 03:12:14 +0000 Pu Lehui wrote: > From: Pu Lehui > > Naresh Kamboju reported a "Bad frame pointer" kernel warning while > running LTP trace ftrace_stress_test.sh in riscv. We can reproduce the > same issue with the following command: > > ``` > $ cd /sys/kernel/debug/tracing > $ echo 'f:myprobe do_nanosleep%return args1=$retval' > dynamic_events > $ echo 1 > events/fprobes/enable > $ echo 1 > tracing_on > $ sleep 1 > ``` > > And we can get the following kernel warning: > > [ 127.692888] ------------[ cut here ]------------ > [ 127.693755] Bad frame pointer: expected ff2000000065be50, received ba34c141e9594000 > [ 127.693755] from func do_nanosleep return to ffffffff800ccb16 > [ 127.698699] WARNING: CPU: 1 PID: 129 at kernel/trace/fgraph.c:755 ftrace_return_to_handler+0x1b2/0x1be > [ 127.699894] Modules linked in: > [ 127.700908] CPU: 1 UID: 0 PID: 129 Comm: sleep Not tainted 6.14.0-rc3-g0ab191c74642 #32 > [ 127.701453] Hardware name: riscv-virtio,qemu (DT) > [ 127.701859] epc : ftrace_return_to_handler+0x1b2/0x1be > [ 127.702032] ra : ftrace_return_to_handler+0x1b2/0x1be > [ 127.702151] epc : ffffffff8013b5e0 ra : ffffffff8013b5e0 sp : ff2000000065bd10 > [ 127.702221] gp : ffffffff819c12f8 tp : ff60000080853100 t0 : 6e00000000000000 > [ 127.702284] t1 : 0000000000000020 t2 : 6e7566206d6f7266 s0 : ff2000000065bd80 > [ 127.702346] s1 : ff60000081262000 a0 : 000000000000007b a1 : ffffffff81894f20 > [ 127.702408] a2 : 0000000000000010 a3 : fffffffffffffffe a4 : 0000000000000000 > [ 127.702470] a5 : 0000000000000000 a6 : 0000000000000008 a7 : 0000000000000038 > [ 127.702530] s2 : ba34c141e9594000 s3 : 0000000000000000 s4 : ff2000000065bdd0 > [ 127.702591] s5 : 00007fff8adcf400 s6 : 000055556dc1d8c0 s7 : 0000000000000068 > [ 127.702651] s8 : 00007fff8adf5d10 s9 : 000000000000006d s10: 0000000000000001 > [ 127.702710] s11: 00005555737377c8 t3 : ffffffff819d899e t4 : ffffffff819d899e > [ 127.702769] t5 : ffffffff819d89a0 t6 : ff2000000065bb18 > [ 127.702826] status: 0000000200000120 badaddr: 0000000000000000 cause: 0000000000000003 > [ 127.703292] [] ftrace_return_to_handler+0x1b2/0x1be > [ 127.703760] [] return_to_handler+0x16/0x26 > [ 127.704009] [] return_to_handler+0x0/0x26 > [ 127.704057] [] common_nsleep+0x42/0x54 > [ 127.704117] [] __riscv_sys_clock_nanosleep+0xba/0x10a > [ 127.704176] [] do_trap_ecall_u+0x188/0x218 > [ 127.704295] [] handle_exception+0x14a/0x156 > [ 127.705436] ---[ end trace 0000000000000000 ]--- > > The reason is that the stack layout for constructing argument for the > ftrace_return_to_handler in the return_to_handler does not match the > __arch_ftrace_regs structure of riscv, leading to unexpected results. > Thanks for fixing! This looks good to me. Reviewed-by: Masami Hiramatsu (Google) Thank you, > Fixes: a3ed4157b7d8 ("fgraph: Replace fgraph_ret_regs with ftrace_regs") > Reported-by: Linux Kernel Functional Testing > Closes: https://lore.kernel.org/all/CA+G9fYvp_oAxeDFj88Tk2rfEZ7jtYKAKSwfYS66=57Db9TBdyA@mail.gmail.com > Signed-off-by: Pu Lehui > Reviewed-by: Alexandre Ghiti > Tested-by: Björn Töpel > --- > arch/riscv/kernel/mcount.S | 24 +++++++++++------------- > 1 file changed, 11 insertions(+), 13 deletions(-) > > diff --git a/arch/riscv/kernel/mcount.S b/arch/riscv/kernel/mcount.S > index 068168046e0e..da4a4000e57e 100644 > --- a/arch/riscv/kernel/mcount.S > +++ b/arch/riscv/kernel/mcount.S > @@ -12,8 +12,6 @@ > #include > #include > > -#define ABI_SIZE_ON_STACK 80 > - > .text > > .macro SAVE_ABI_STATE > @@ -28,12 +26,12 @@ > * register if a0 was not saved. > */ > .macro SAVE_RET_ABI_STATE > - addi sp, sp, -ABI_SIZE_ON_STACK > - REG_S ra, 1*SZREG(sp) > - REG_S s0, 8*SZREG(sp) > - REG_S a0, 10*SZREG(sp) > - REG_S a1, 11*SZREG(sp) > - addi s0, sp, ABI_SIZE_ON_STACK > + addi sp, sp, -FREGS_SIZE_ON_STACK > + REG_S ra, FREGS_RA(sp) > + REG_S s0, FREGS_S0(sp) > + REG_S a0, FREGS_A0(sp) > + REG_S a1, FREGS_A1(sp) > + addi s0, sp, FREGS_SIZE_ON_STACK > .endm > > .macro RESTORE_ABI_STATE > @@ -43,11 +41,11 @@ > .endm > > .macro RESTORE_RET_ABI_STATE > - REG_L ra, 1*SZREG(sp) > - REG_L s0, 8*SZREG(sp) > - REG_L a0, 10*SZREG(sp) > - REG_L a1, 11*SZREG(sp) > - addi sp, sp, ABI_SIZE_ON_STACK > + REG_L ra, FREGS_RA(sp) > + REG_L s0, FREGS_S0(sp) > + REG_L a0, FREGS_A0(sp) > + REG_L a1, FREGS_A1(sp) > + addi sp, sp, FREGS_SIZE_ON_STACK > .endm > > SYM_TYPED_FUNC_START(ftrace_stub) > -- > 2.34.1 > -- Masami Hiramatsu (Google)