From patchwork Fri Oct 18 17:36:17 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hari Bathini X-Patchwork-Id: 13842101 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 0FE922040A3; Fri, 18 Oct 2024 17:37:14 +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=1729273036; cv=none; b=Yv8sVLetnUvtmcXhQIdwT7GkGm3wWJ7L9BReh3Ha2208mYY3zLv/gbBKYI8upl/YaPldIZR8+eU+4lfNx2uxM2mC6ZHLFPYKZv7N08y4uT5O8ArzcFsUraoW/qBlpJCevm+HxE3nu32hhNduPypMelJD4SO3QG1BGVja4lQa+C8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729273036; c=relaxed/simple; bh=pIR22lqg8pg9hsT1pgKfaYSCLQAG86rJjvc4Jfs7BCg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rca0hDvidCTHn+TfEBaE+t08wKhedAvXVeGO/4gto+bvR01cldXtGiavFczg6VoCsiCr3IsknW5Uh4dZ5DoCM5LkzR5rWDE5VXazvuvAYWrPMflKxtONr4u++EXYlEzECkAeTXyq358eHAjYB3Xvm7bEMiGAAR5N//aWeIEG+4Q= 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=hvf60Hwx; 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="hvf60Hwx" Received: from pps.filterd (m0356516.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49I7v3V3014400; Fri, 18 Oct 2024 17:36:52 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=ke58AxBSPUQS3/T4M vvz9VCq7Eju0gHJsQVTBJZ8QTc=; b=hvf60HwxO4ZkBuHa7No2V0A5VKl3d9hMn g+JcwAeaLdlVBvapnELxxNbUPDn0WSrZe4PDyBBKT9NRBartgOflBVmGZhtW5c2I dyzZRIQxI7o5FZ5wcV0zkFtdX/faAbpCIsZJPzm7cearT93KE0mccrYxHpkcKHP9 SVudi0Kz+9kJOQHB2Bvvp+USZ7C4lmgTualBUq5KDJh1J+oscs9Ay/tTP4T57Zna u4yxEpiix3fwBC/a4+wyrjsu4SLiPNCWs4ztVVLjEdzIlsGMMjJWGlVU+u5LBlVi DYBcF4QcTRl9TFgPBj+M3qG3PcFH6Pr+NW+oh5shKjkCDXVs2ryFA== Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 42aqgracfh-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 18 Oct 2024 17:36:52 +0000 (GMT) Received: from m0356516.ppops.net (m0356516.ppops.net [127.0.0.1]) by pps.reinject (8.18.0.8/8.18.0.8) with ESMTP id 49IHap9n009911; Fri, 18 Oct 2024 17:36:51 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 42aqgracfe-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 18 Oct 2024 17:36:51 +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 49IEjA4a006761; Fri, 18 Oct 2024 17:36:50 GMT Received: from smtprelay01.fra02v.mail.ibm.com ([9.218.2.227]) by ppma23.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4284xknurc-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 18 Oct 2024 17:36:50 +0000 Received: from smtpav01.fra02v.mail.ibm.com (smtpav01.fra02v.mail.ibm.com [10.20.54.100]) by smtprelay01.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 49IHaktV56230306 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 18 Oct 2024 17:36:46 GMT Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 9EE772004B; Fri, 18 Oct 2024 17:36:46 +0000 (GMT) Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 93C2720040; Fri, 18 Oct 2024 17:36:42 +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 17:36:42 +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 02/17] powerpc/kprobes: Use ftrace to determine if a probe is at function entry Date: Fri, 18 Oct 2024 23:06:17 +0530 Message-ID: <20241018173632.277333-3-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-ORIG-GUID: q2keNPn7-Oh3zYQlEMQ1SBemYkmQqC5B X-Proofpoint-GUID: Tl-0OX7UmqfkzAmqZW8xwA4Md_8ZKBpy 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 phishscore=0 mlxlogscore=999 malwarescore=0 clxscore=1015 lowpriorityscore=0 adultscore=0 spamscore=0 mlxscore=0 suspectscore=0 impostorscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.19.0-2409260000 definitions=main-2410180111 From: Naveen N Rao Rather than hard-coding the offset into a function to be used to determine if a kprobe is at function entry, use ftrace_location() to determine the ftrace location within the function and categorize all instructions till that offset to be function entry. For functions that cannot be traced, we fall back to using a fixed offset of 8 (two instructions) to categorize a probe as being at function entry for 64-bit elfv2, unless we are using pcrel. Acked-by: Masami Hiramatsu (Google) Signed-off-by: Naveen N Rao --- arch/powerpc/kernel/kprobes.c | 18 ++++++++---------- 1 file changed, 8 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index f8aa91bc3b17..bf382c459e1f 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -105,24 +105,22 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset) return addr; } -static bool arch_kprobe_on_func_entry(unsigned long offset) +static bool arch_kprobe_on_func_entry(unsigned long addr, unsigned long offset) { -#ifdef CONFIG_PPC64_ELF_ABI_V2 -#ifdef CONFIG_KPROBES_ON_FTRACE - return offset <= 16; -#else - return offset <= 8; -#endif -#else + unsigned long ip = ftrace_location(addr); + + if (ip) + return offset <= (ip - addr); + if (IS_ENABLED(CONFIG_PPC64_ELF_ABI_V2) && !IS_ENABLED(CONFIG_PPC_KERNEL_PCREL)) + return offset <= 8; return !offset; -#endif } /* XXX try and fold the magic of kprobe_lookup_name() in this */ kprobe_opcode_t *arch_adjust_kprobe_addr(unsigned long addr, unsigned long offset, bool *on_func_entry) { - *on_func_entry = arch_kprobe_on_func_entry(offset); + *on_func_entry = arch_kprobe_on_func_entry(addr, offset); return (kprobe_opcode_t *)(addr + offset); }