From nobody Thu Dec 18 06:00:26 2025 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E402C12FF72; Tue, 9 Jul 2024 09:55:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=114.242.206.163 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720518913; cv=none; b=bfe4+WZ+MzXvsoelce/g0KFdIGaoaxFBPu7WHoUk5H88eK/rAdFrmSIaUAqZteJ2d5dpJJ/rZztp3VrR3xZ7jyzsTeLG4NarIa3UcBMs33SQD/Ftr3BpvSQamDa4KJF7j3CVNzXkEYoQ073mXDV3n05c0+V+EkEZqpT+6xIUkb0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720518913; c=relaxed/simple; bh=wp8lBSzF7UKAvYS4c5rsFNiAZ/uGj+OLNOgegi/v/Yk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bZcVpeTIBYJii08CWEdZpJMx9ohYTat9XHxDS7jYqAwcuBOv/s2UUvWZ6uhscrX/bw71cKH/kObPQ8ZWzSkLNT/K2rQCwPdu6afiAai/Npbae1fJSj1S+4TPrcKNg/ZpIzTHxg2GIq1JDjov5y6j16LQf3fe96hEexO5C3YCNEQ= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn; spf=pass smtp.mailfrom=loongson.cn; arc=none smtp.client-ip=114.242.206.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=loongson.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=loongson.cn Received: from loongson.cn (unknown [113.200.148.30]) by gateway (Coremail) with SMTP id _____8Axjuv9CI1mXWACAA--.6999S3; Tue, 09 Jul 2024 17:55:09 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8Cxqsb6CI1mgt1AAA--.17645S4; Tue, 09 Jul 2024 17:55:08 +0800 (CST) From: Tiezhu Yang To: Will Deacon , Mark Rutland , Russell King , Catalin Marinas , Oleg Nesterov , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Namhyung Kim Cc: linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v3 2/3] arm: hw_breakpoint: Save privilege of access control via ptrace Date: Tue, 9 Jul 2024 17:55:05 +0800 Message-ID: <20240709095506.9691-3-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20240709095506.9691-1-yangtiezhu@loongson.cn> References: <20240709095506.9691-1-yangtiezhu@loongson.cn> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: AQAAf8Cxqsb6CI1mgt1AAA--.17645S4 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoW7CF18JryDGr4kur18ZrWrJFc_yoW8uF1Dp3 sxCw1qqr4DCa10ga9xtrs5Za15C3sFgry2ga4DKw4Yyr1Yvr93GFykGr9I9393tr40q34S qwsYvr42qw47XabCm3ZEXasCq-sJn29KB7ZKAUJUUUU3529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUB2b4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVWxJr0_GcWln4kS14v26r126r1DM2AIxVAIcxkEcVAq07x20xvEncxIr21l57IF6xkI12 xvs2x26I8E6xACxx1l5I8CrVACY4xI64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r1q 6rW5McIj6I8E87Iv67AKxVW8JVWxJwAm72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64 vIr41lc7CjxVAaw2AFwI0_Jw0_GFyl42xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_ Jr0_Gr1l4IxYO2xFxVAFwI0_JF0_Jw1lx2IqxVAqx4xG67AKxVWUJVWUGwC20s026x8Gjc xK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r1q6r43MIIYrxkI7VAKI48JMIIF0xvE2Ix0 cI8IcVAFwI0_Xr0_Ar1lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4j6F4UMIIF0xvE42xK8V AvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVW8JVWxJwCI42IY6I8E87Iv6xkF7I0E 14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxU4YLvDUUUU Content-Type: text/plain; charset="utf-8" In the current code, decode_ctrl_reg() saves the privilege of access control passed by the ptrace user data, but it is not used anymore, arch_build_bp_info() checks whether bp virtual address is in kernel space to construct hw->ctrl.privilege, it seems not reasonable. The value of ctrl->privilege saved in decode_ctrl_reg() can be used in arch_build_bp_info(), there is no need to check bp virtual address to assign value for hw->ctrl.privilege, just make use of "bp_priv" in the struct perf_event_attr to save the privilege of access control via ptrace for hardware breakpoint. Signed-off-by: Tiezhu Yang --- arch/arm/kernel/hw_breakpoint.c | 4 +--- arch/arm/kernel/ptrace.c | 2 ++ 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/arm/kernel/hw_breakpoint.c b/arch/arm/kernel/hw_breakpoin= t.c index a12efd0f43e8..7720d39473d9 100644 --- a/arch/arm/kernel/hw_breakpoint.c +++ b/arch/arm/kernel/hw_breakpoint.c @@ -568,9 +568,7 @@ static int arch_build_bp_info(struct perf_event *bp, hw->address =3D attr->bp_addr; =20 /* Privilege */ - hw->ctrl.privilege =3D ARM_BREAKPOINT_USER; - if (arch_check_bp_in_kernelspace(hw)) - hw->ctrl.privilege |=3D ARM_BREAKPOINT_PRIV; + hw->ctrl.privilege =3D attr->bp_priv; =20 /* Enabled? */ hw->ctrl.enabled =3D !attr->disabled; diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index c421a899fc84..0d6d6b2a57a0 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -422,6 +422,7 @@ static struct perf_event *ptrace_hbp_create(struct task= _struct *tsk, int type) attr.bp_addr =3D 0; attr.bp_len =3D HW_BREAKPOINT_LEN_4; attr.bp_type =3D type; + attr.bp_priv =3D ARM_BREAKPOINT_USER; attr.disabled =3D 1; =20 return register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, @@ -530,6 +531,7 @@ static int ptrace_sethbpregs(struct task_struct *tsk, l= ong num, =20 attr.bp_len =3D gen_len; attr.bp_type =3D gen_type; + attr.bp_priv =3D ctrl.privilege; attr.disabled =3D !ctrl.enabled; } =20 --=20 2.42.0