From patchwork Fri Oct 18 17:36:19 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hari Bathini X-Patchwork-Id: 13842102 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 1A3A120403F; Fri, 18 Oct 2024 17:37:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729273045; cv=none; b=TEu3w3mDYtnhhISfvN1Y16DIQUVYZwmaHPNYKwovssAUZn15du+CQqVQyFpQIf1abuUMkyA8ylJ59V4TNVt7WnuhjBaYTHTZg9JOOaTUHqXQn3L5dvWciDhe/BsHADHLdGEoprsXzFXqnqr5DPne5h1wMowXn3dDGFqcl8MLWeI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729273045; c=relaxed/simple; bh=+W95hfalgBx+aCZjq4y20IiUOmE+GTOeYOkNUDcxi8Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Gd8b3DrfLk3Tp5aSv/hSFZavbYVq6Y+9JnrFVg/lHRZ0zMt5G/SlU6x1SloeneJ/pbg88sFVlrH/g+7ZM1M5hAa1tN7WAWoaup8kxxBWvl5/6DAssgLlDhWntd1GnBoJpPo3hnqQlzlvFFBHuhH68ttNz+mTVxX1Tb0l9mwNpFs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=irDz35dm; arc=none smtp.client-ip=148.163.158.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="irDz35dm" Received: from pps.filterd (m0353725.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49I9lo9m008102; Fri, 18 Oct 2024 17:37:01 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=s0FRCiVrpvEhkqmos saMa+/8pdEQ0r3/FwKVmEn10sc=; b=irDz35dmdMv18xTHQ6/b+OYhjOR/z2mJM MJ7Ud2bO4ywVt4D/x94Lc1Qm6ScJh+eHcOIxu3YFSmCXHQweMaS4geYnNzBlHPMT mumfaChrujD90Y30eFL1bxhquW8iE7FmJ7dw0YxZVS848nfGVyFsWs2fI70o90uX qpIK+7lSahXtQhE3hBijqdi1SZp+61gPwG/SEPyPGOvx/dAfL+ckwGpDyEB2JpRc kcHPzNs22iEDX+otDxecRMeqKYbeyeFoGbqly76a1ePMqjHVrNoBCastEvhhuhEP 6OxEmz+zH2ghVeFTDhZL6rCVm3OxCx3L/SeOKOIoT/m1uMtoH2qTA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 42as8aa274-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 18 Oct 2024 17:37:00 +0000 (GMT) Received: from m0353725.ppops.net (m0353725.ppops.net [127.0.0.1]) by pps.reinject (8.18.0.8/8.18.0.8) with ESMTP id 49IHb08u011544; Fri, 18 Oct 2024 17:37:00 GMT Received: from ppma23.wdc07v.mail.ibm.com (5d.69.3da9.ip4.static.sl-reverse.com [169.61.105.93]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 42as8aa26w-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 18 Oct 2024 17:37:00 +0000 (GMT) Received: from pps.filterd (ppma23.wdc07v.mail.ibm.com [127.0.0.1]) by ppma23.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 49IF0Shb006757; Fri, 18 Oct 2024 17:36:59 GMT Received: from smtprelay03.fra02v.mail.ibm.com ([9.218.2.224]) by ppma23.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4284xknurs-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 18 Oct 2024 17:36:59 +0000 Received: from smtpav01.fra02v.mail.ibm.com (smtpav01.fra02v.mail.ibm.com [10.20.54.100]) by smtprelay03.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 49IHatGQ39584066 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 18 Oct 2024 17:36:55 GMT Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B719020043; Fri, 18 Oct 2024 17:36:55 +0000 (GMT) Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9EBFB20040; Fri, 18 Oct 2024 17:36:51 +0000 (GMT) Received: from li-bd3f974c-2712-11b2-a85c-df1cec4d728e.ibm.com.com (unknown [9.43.99.188]) by smtpav01.fra02v.mail.ibm.com (Postfix) with ESMTP; Fri, 18 Oct 2024 17:36:51 +0000 (GMT) From: Hari Bathini To: linuxppc-dev , bpf@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Michael Ellerman , "Naveen N. Rao" , Mark Rutland , Daniel Borkmann , Masahiro Yamada , Nicholas Piggin , Alexei Starovoitov , Steven Rostedt , Masami Hiramatsu , Andrii Nakryiko , Christophe Leroy , Vishal Chourasia , Mahesh J Salgaonkar Subject: [PATCH v6 04/17] powerpc32/ftrace: Unify 32-bit and 64-bit ftrace entry code Date: Fri, 18 Oct 2024 23:06:19 +0530 Message-ID: <20241018173632.277333-5-hbathini@linux.ibm.com> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241018173632.277333-1-hbathini@linux.ibm.com> References: <20241018173632.277333-1-hbathini@linux.ibm.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: 8TEt5P_BR_tEhgERfgAfUtj09TS_ZnVo X-Proofpoint-ORIG-GUID: sHcwMwaMmyu_9Y5NJ9s8Gr3A5XxspGpc X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-15_01,2024-10-11_01,2024-09-30_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 mlxscore=0 lowpriorityscore=0 suspectscore=0 mlxlogscore=999 phishscore=0 adultscore=0 impostorscore=0 priorityscore=1501 spamscore=0 malwarescore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2410180111 From: Naveen N Rao On 32-bit powerpc, gcc generates a three instruction sequence for function profiling: mflr r0 stw r0, 4(r1) bl _mcount On kernel boot, the call to _mcount() is nop-ed out, to be patched back in when ftrace is actually enabled. The 'stw' instruction therefore is not necessary unless ftrace is enabled. Nop it out during ftrace init. When ftrace is enabled, we want the 'stw' so that stack unwinding works properly. Perform the same within the ftrace handler, similar to 64-bit powerpc. Reviewed-by: Nicholas Piggin Signed-off-by: Naveen N Rao --- arch/powerpc/kernel/trace/ftrace.c | 6 ++++-- arch/powerpc/kernel/trace/ftrace_entry.S | 4 ++-- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c index 2ef504700e8d..8c3e523e4f96 100644 --- a/arch/powerpc/kernel/trace/ftrace.c +++ b/arch/powerpc/kernel/trace/ftrace.c @@ -240,8 +240,10 @@ int ftrace_init_nop(struct module *mod, struct dyn_ftrace *rec) } else if (IS_ENABLED(CONFIG_PPC32)) { /* Expected sequence: 'mflr r0', 'stw r0,4(r1)', 'bl _mcount' */ ret = ftrace_validate_inst(ip - 8, ppc_inst(PPC_RAW_MFLR(_R0))); - if (!ret) - ret = ftrace_validate_inst(ip - 4, ppc_inst(PPC_RAW_STW(_R0, _R1, 4))); + if (ret) + return ret; + ret = ftrace_modify_code(ip - 4, ppc_inst(PPC_RAW_STW(_R0, _R1, 4)), + ppc_inst(PPC_RAW_NOP())); } else if (IS_ENABLED(CONFIG_MPROFILE_KERNEL)) { /* Expected sequence: 'mflr r0', ['std r0,16(r1)'], 'bl _mcount' */ ret = ftrace_read_inst(ip - 4, &old); diff --git a/arch/powerpc/kernel/trace/ftrace_entry.S b/arch/powerpc/kernel/trace/ftrace_entry.S index 76dbe9fd2c0f..244a1c7bb1e8 100644 --- a/arch/powerpc/kernel/trace/ftrace_entry.S +++ b/arch/powerpc/kernel/trace/ftrace_entry.S @@ -33,6 +33,8 @@ * and then arrange for the ftrace function to be called. */ .macro ftrace_regs_entry allregs + /* Save the original return address in A's stack frame */ + PPC_STL r0, LRSAVE(r1) /* Create a minimal stack frame for representing B */ PPC_STLU r1, -STACK_FRAME_MIN_SIZE(r1) @@ -44,8 +46,6 @@ SAVE_GPRS(3, 10, r1) #ifdef CONFIG_PPC64 - /* Save the original return address in A's stack frame */ - std r0, LRSAVE+SWITCH_FRAME_SIZE+STACK_FRAME_MIN_SIZE(r1) /* Ok to continue? */ lbz r3, PACA_FTRACE_ENABLED(r13) cmpdi r3, 0