From nobody Thu Dec 18 06:03:20 2025 Received: from mail.loongson.cn (mail.loongson.cn [114.242.206.163]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3D61C153820; 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=lgBIrsnzmr0vHjlUzbtrh17yBLa4qXE0/SPDzI4zTCg0Ay+FjuiN78ijnKQ/iIQtCATHqsMEzBKsShm2vy2SM1uchz+eI6FBHnMNZMLeuQzwHQPoIFyK/NV8FUTgCEXlp5f9J7dZBkpXQOuHVlA6zioCbOWxkAjIv+30KeS6Cjw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720518913; c=relaxed/simple; bh=eax1Aaob4BNuHp+SZvgWyc+FoEJ7G16Gq6WLfGlD/Rc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=F1fw8G1655u75NvSuOwKuMliYMmN8Rku9eLI10CL7t6b1V6IflK8Gr3s3urIiPlQsgGNIR/pYGw83ift+TGm42w21poK2Ezu47eZRaOuEa0WJXcMAZ2xHQjuPQryVN5SpesbzM+xPSpKvLAGyKCtbgwOyfA4t9jRyU2gR3KG9GU= 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 _____8Cxruv9CI1mZGACAA--.7073S3; 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--.17645S5; Tue, 09 Jul 2024 17:55:09 +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 3/3] arm64: hw_breakpoint: Save privilege of access control via ptrace Date: Tue, 9 Jul 2024 17:55:06 +0800 Message-ID: <20240709095506.9691-4-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--.17645S5 X-CM-SenderInfo: p1dqw3xlh2x3gn0dqz5rrqw2lrqou0/ X-Coremail-Antispam: 1Uk129KBj93XoW7CF18JryDGr4kur18ZrWrJFc_yoW8tw4Dpr ZxAw1qqw4UGa1UGayaqws3Zan8GwsFgryUXryDG3ySkr15Zr1fWrykGrnxurZ3JrW0q3y0 v3yDXr15Wa17X3XCm3ZEXasCq-sJn29KB7ZKAUJUUUU3529EdanIXcx71UUUUU7KY7ZEXa sCq-sGcSsGvfJ3Ic02F40EFcxC0VAKzVAqx4xG6I80ebIjqfuFe4nvWSU5nxnvy29KBjDU 0xBIdaVrnRJUUUBIb4IE77IF4wAFF20E14v26r1j6r4UM7CY07I20VC2zVCF04k26cxKx2 IYs7xG6rWj6s0DM7CIcVAFz4kK6r1Y6r17M28lY4IEw2IIxxk0rwA2F7IY1VAKz4vEj48v e4kI8wA2z4x0Y4vE2Ix0cI8IcVAFwI0_Xr0_Ar1l84ACjcxK6xIIjxv20xvEc7CjxVAFwI 0_Cr0_Gr1UM28EF7xvwVC2z280aVAFwI0_Gr1j6F4UJwA2z4x0Y4vEx4A2jsIEc7CjxVAF wI0_Cr1j6rxdM2kKe7AKxVWUAVWUtwAS0I0E0xvYzxvE52x082IY62kv0487Mc804VCY07 AIYIkI8VC2zVCFFI0UMc02F40EFcxC0VAKzVAqx4xG6I80ewAv7VC0I7IYx2IY67AKxVWU tVWrXwAv7VC2z280aVAFwI0_Gr0_Cr1lOx8S6xCaFVCjc4AY6r1j6r4UM4x0Y48IcxkI7V AKI48JMxkF7I0En4kS14v26r1q6r43MxAIw28IcxkI7VAKI48JMxC20s026xCaFVCjc4AY 6r1j6r4UMxCIbckI1I0E14v26r126r1DMI8I3I0E5I8CrVAFwI0_Jr0_Jr4lx2IqxVCjr7 xvwVAFwI0_JrI_JrWlx4CE17CEb7AF67AKxVWUtVW8ZwCIc40Y0x0EwIxGrwCI42IY6xII jxv20xvE14v26ryj6F1UMIIF0xvE2Ix0cI8IcVCY1x0267AKxVW8JVWxJwCI42IY6xAIw2 0EY4v20xvaj40_Jr0_JF4lIxAIcVC2z280aVAFwI0_Gr0_Cr1lIxAIcVC2z280aVCY1x02 67AKxVW8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7IU8XTm3UUUUU== 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/arm64/kernel/hw_breakpoint.c | 11 ++--------- arch/arm64/kernel/ptrace.c | 2 ++ 2 files changed, 4 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; } --=20 2.42.0