From nobody Tue Dec 16 13:47:56 2025 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id DBBF918E1D; Tue, 18 Jun 2024 07:10:16 +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=1718694621; cv=none; b=pslt61hzJdc4qO8xddqpjOCjUu4Q1aFCXM51eOLtXS97Vxj6GQzUkXvXu7OoG9ddicP1DZpWcrXl/YQ7X9TyioNPwP4GrNU2FPmjJRKa8hcI9bEQureTzT2LrMno+JdlMCrAIr6SKg9DVLeUiuLiEcjQrf3aMHz6zX19Z3acMWU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1718694621; c=relaxed/simple; bh=lmTv/KAeEkjTzx8D0XnC+oN9HgVt5RqE2kA2Aj0kdao=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=t4ivR8TnWDXtxC06yh4lKXq4y4hgjjci2hQxUl/kYwWxVLZDC3eARlcBdRyxfHlkVLB7KIHbWeRZF7PZmrZ7LS8r0yyyDpktrQsgjkDDrn8iXLpCMaKSWRyt4yUIP0aqV+I4QuCdKZFVJxpY5gyaZHLFgNcNtuh6716r3i4vG+c= 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 _____8Ax3erWMnFmfNQHAA--.31460S3; Tue, 18 Jun 2024 15:10:14 +0800 (CST) Received: from linux.localdomain (unknown [113.200.148.30]) by localhost.localdomain (Coremail) with SMTP id AQAAf8CxosTSMnFmXgcnAA--.17923S2; Tue, 18 Jun 2024 15:10:11 +0800 (CST) From: Tiezhu Yang To: Will Deacon , Mark Rutland , 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] arm64: hw_breakpoint: Save privilege of access control via ptrace Date: Tue, 18 Jun 2024 15:10:10 +0800 Message-ID: <20240618071010.11214-1-yangtiezhu@loongson.cn> X-Mailer: git-send-email 2.42.0 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: AQAAf8CxosTSMnFmXgcnAA--.17923S2 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoWxAw1kWFy8XFWkWw4xJw4DZFc_yoW5Zry3pr ZxCrn5tw4UGayjgasxtws5Z3y5JwsrWrZxWa4q9w4Fkr13Z393WF97Wr9Iv390grW8ZayF qw4qgr4rK3WUXagCm3ZEXasCq-sJn29KB7ZKAUJUUUUx529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUBIb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_JFI_Gr1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Gr0_Cr1l84ACjcxK6I8E87Iv67AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVCY1x0267AK xVW8Jr0_Cr1UM2kKe7AKxVWUAVWUtwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07 AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWU AVWUtwAv7VC2z280aVAFwI0_Jr0_Gr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7V AKI48JMxkF7I0En4kS14v26r1q6r43MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY 6r1j6r4UMxCIbckI1I0E14v26r126r1DMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7 xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xII jxv20xvE14v26r1I6r4UMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw2 0EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x02 67AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU8svtJUUUUU== Content-Type: text/plain; charset="utf-8" Currently, decode_ctrl_reg() saves the privilege of access control which is not used anymore, arch_build_bp_info() checks whether bp virtual address is in kernel space to construct hw->ctrl.privilege, the process seems not reasonable. Add a member "bp_priv" in struct perf_event_attr to make a bridge between ptrace and hardware breakpoint, it can save the privilege of access control via ptrace for hardware breakpoint. Signed-off-by: Tiezhu Yang --- This patch is based on 6.10-rc4, cross compile tested only. This is a try and preparation for later patch on LoongArch. arch/arm64/kernel/hw_breakpoint.c | 11 ++--------- arch/arm64/kernel/ptrace.c | 2 ++ include/uapi/linux/perf_event.h | 1 + kernel/events/hw_breakpoint.c | 1 + 4 files changed, 6 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_break= point.c index 722ac45f9f7b..06e34bcdcf92 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -486,15 +486,8 @@ static int arch_build_bp_info(struct perf_event *bp, /* Address */ hw->address =3D attr->bp_addr; =20 - /* - * Privilege - * Note that we disallow combined EL0/EL1 breakpoints because - * that would complicate the stepping code. - */ - if (arch_check_bp_in_kernelspace(hw)) - hw->ctrl.privilege =3D AARCH64_BREAKPOINT_EL1; - else - hw->ctrl.privilege =3D AARCH64_BREAKPOINT_EL0; + /* Privilege */ + hw->ctrl.privilege =3D attr->bp_priv; =20 /* Enabled? */ hw->ctrl.enabled =3D !attr->disabled; diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index 0d022599eb61..3b37c4a2e0d4 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -309,6 +309,7 @@ static struct perf_event *ptrace_hbp_create(unsigned in= t note_type, attr.bp_addr =3D 0; attr.bp_len =3D HW_BREAKPOINT_LEN_4; attr.bp_type =3D type; + attr.bp_priv =3D AARCH64_BREAKPOINT_EL0; attr.disabled =3D 1; =20 bp =3D register_user_hw_breakpoint(&attr, ptrace_hbptriggered, NULL, tsk); @@ -352,6 +353,7 @@ static int ptrace_hbp_fill_attr_ctrl(unsigned int note_= type, attr->bp_len =3D len; attr->bp_type =3D type; attr->bp_addr +=3D offset; + attr->bp_priv =3D ctrl.privilege; =20 return 0; } diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_even= t.h index 3a64499b0f5d..88dcaba421cc 100644 --- a/include/uapi/linux/perf_event.h +++ b/include/uapi/linux/perf_event.h @@ -467,6 +467,7 @@ struct perf_event_attr { __u32 wakeup_watermark; /* bytes before wakeup */ }; =20 + __u8 bp_priv; __u32 bp_type; union { __u64 bp_addr; diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c index 6c2cb4e4f48d..3ad16b226e4f 100644 --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -754,6 +754,7 @@ static void hw_breakpoint_copy_attr(struct perf_event_a= ttr *to, to->bp_addr =3D from->bp_addr; to->bp_type =3D from->bp_type; to->bp_len =3D from->bp_len; + to->bp_priv =3D from->bp_priv; to->disabled =3D from->disabled; } =20 --=20 2.42.0