From patchwork Wed Oct 30 07:08:37 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hari Bathini X-Patchwork-Id: 13856048 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 8EA281E0E00; Wed, 30 Oct 2024 07:09:43 +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=1730272185; cv=none; b=rfOaW0sKjgFKFI/jtWBlzCHLe2GS3iIQ8kpIRflcLawxUXpfnXDqT+d/5VKwZh6siSMFC/ciRNceuBAfQruOlzcA5TAscXip3/e/4DfJnuYuf4mhLrg7yUE1X8og5Ec0E+vcl07zmp1MbPBbbpvXZx+59aA1yOq/NroOR5l08RY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730272185; c=relaxed/simple; bh=+W95hfalgBx+aCZjq4y20IiUOmE+GTOeYOkNUDcxi8Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=KrVVFg6P1n5q8c/UckHiSpHnYyispMjuDtcK6Bx8lIW2iNnbk5KEfeesIDnehJ5/cYTpsMP4N3MK+POPjskZtdSeubhficGmUU2YjSAQVT0cE5jyLeExsHBhCOAiSDbr+3xCAdsBXlwlzc5XjrjLxYjpiMDjqfw1Bd5OWQpOwSM= 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=bNSELzfj; 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="bNSELzfj" 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 49U2d4tG025654; Wed, 30 Oct 2024 07:09:16 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=bNSELzfjoop8ROkSfvOdzwpBxVg3ihwXG o4UYvy15ZJi0yOLoZGYmUbdkh/VJQ/K+qF5f1Zf+oxD3W26Dv5w4uxcah2+T3wlM q+uzc+GeHJGwIZcrDbdFkJ7J9pRFlr3EhTtDCfz01CTxilaNB4u8hcRwgtRqNEP0 vP8LfvIkck4lvuqssML+DvxpDImfvmZjyWYK8xd5gen4+Oaaf0t13b/r9tWOPOvc EGkE3BSY5RNCPqUGYXX3fqzlpLYQutUI+woM8OWqX/tEj+PAfzCqywCfdvTmduCZ 8YVMewBODNLuEOlYtiujptts+TpAHiH4CQ+sv1wGpYt4siefszk6Q== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 42jb65h2xq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 30 Oct 2024 07:09:16 +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 49U79F7D018962; Wed, 30 Oct 2024 07:09:15 GMT Received: from ppma12.dal12v.mail.ibm.com (dc.9e.1632.ip4.static.sl-reverse.com [50.22.158.220]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 42jb65h2xm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 30 Oct 2024 07:09:15 +0000 (GMT) Received: from pps.filterd (ppma12.dal12v.mail.ibm.com [127.0.0.1]) by ppma12.dal12v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 49U6WrvN017410; Wed, 30 Oct 2024 07:09:15 GMT Received: from smtprelay04.fra02v.mail.ibm.com ([9.218.2.228]) by ppma12.dal12v.mail.ibm.com (PPS) with ESMTPS id 42harsf3nm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 30 Oct 2024 07:09:14 +0000 Received: from smtpav05.fra02v.mail.ibm.com (smtpav05.fra02v.mail.ibm.com [10.20.54.104]) by smtprelay04.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 49U79BpE17105220 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 30 Oct 2024 07:09:11 GMT Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 601662004B; Wed, 30 Oct 2024 07:09:11 +0000 (GMT) Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D0B0D20043; Wed, 30 Oct 2024 07:09:07 +0000 (GMT) Received: from li-bd3f974c-2712-11b2-a85c-df1cec4d728e.in.ibm.com (unknown [9.203.115.143]) by smtpav05.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 30 Oct 2024 07:09:07 +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 v7 04/17] powerpc32/ftrace: Unify 32-bit and 64-bit ftrace entry code Date: Wed, 30 Oct 2024 12:38:37 +0530 Message-ID: <20241030070850.1361304-5-hbathini@linux.ibm.com> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241030070850.1361304-1-hbathini@linux.ibm.com> References: <20241030070850.1361304-1-hbathini@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: xEK9_mj46FhoXGBHGnh-LC3EpLPhFI9g X-Proofpoint-GUID: X6v5Xhr9a9WzsB0MWhS3BtSSm_qp0PR7 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 priorityscore=1501 clxscore=1015 adultscore=0 phishscore=0 bulkscore=0 mlxlogscore=999 impostorscore=0 spamscore=0 suspectscore=0 mlxscore=0 malwarescore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2410300051 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