From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-188.mta1.migadu.com (out-188.mta1.migadu.com [95.215.58.188]) (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 75FC378F54 for ; Thu, 2 Oct 2025 15:49:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.188 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759420159; cv=none; b=mHHEp1PCwDcTit0+uIXoXcfrdNjIbpUHcKDLcUnijeDBpFzdJ5CgtzqZB/URxvidUxcASx/qPwCKYJg8zvNQSzD+BNbS5vQZX/H0JjOu9cj7W5NPP6wMYObRF8ZgW8Gcc/tmnZpjHqemtzVeUCT0JNWrAQGpiRZgpP0Zm9gX/lM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759420159; c=relaxed/simple; bh=CJbcxa6J9kkpGWqgfBjvE9mbuUonkhQDtbdbGO9AiLc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LIHK49TYmLbaTGezuv29kD/OAAgOPqWNsAmm+Q9z/YSLhKTDKNkMbVMARR8eGxGQ8qhlsz/9+O6awOKrh/tJ8BMFCkpirAUKJuEuVh4rfUWMAnbHxXuR5gGxbclHTLxaiF0TT18R8oycqdzZuqlwtGPT4VqtYPhJuMRVBNvlyOg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=tGSM2t2H; arc=none smtp.client-ip=95.215.58.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="tGSM2t2H" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1759420155; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=qkIEtwiKm/PBLHqxy7L/Y04AyqV06neykKJrqVj9eSo=; b=tGSM2t2HlZA8fr8RgR+Bi0v5nqc5F/bXhT7WSdPVHhxFzHKCYxypuOs2PvgmCi4qLXLH2Y WbOdFMMn7q3T/5vKSsvt+L5pXB+WsFqYgfIeNUg1PXoUz0bgwPY+rCce7RM6nWJKkaln9x YIrSPw47PDObfZqIkksfE67OyDIeWHc= From: Leon Hwang To: bpf@vger.kernel.org Cc: ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net, Leon Hwang Subject: [RFC PATCH bpf-next v3 01/10] bpf: Extend bpf syscall with common attributes support Date: Thu, 2 Oct 2025 23:48:32 +0800 Message-ID: <20251002154841.99348-2-leon.hwang@linux.dev> In-Reply-To: <20251002154841.99348-1-leon.hwang@linux.dev> References: <20251002154841.99348-1-leon.hwang@linux.dev> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Extend the 'bpf()' syscall to support a set of common attributes shared across all BPF commands: 1. 'log_buf': User-provided buffer for storing logs. 2. 'log_size': Size of the log buffer. 3. 'log_level': Log verbosity level. 4. 'log_true_size': The size of log reported by kernel. These common attributes are passed as the 4th argument to the 'bpf()' syscall, with the 5th argument specifying the size of this structure. To indicate the use of these common attributes from userspace, a new flag 'BPF_COMMON_ATTRS' ('1 << 16') is introduced. This flag is OR-ed into the 'cmd' field of the syscall. When 'cmd & BPF_COMMON_ATTRS' is set, the kernel will copy the common attributes from userspace into kernel space for use. Signed-off-by: Leon Hwang --- include/linux/syscalls.h | 3 ++- include/uapi/linux/bpf.h | 8 ++++++++ kernel/bpf/syscall.c | 23 +++++++++++++++++++---- tools/include/uapi/linux/bpf.h | 8 ++++++++ 4 files changed, 37 insertions(+), 5 deletions(-) diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index 77f45e5d44139..94408575dc49b 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -933,7 +933,8 @@ asmlinkage long sys_seccomp(unsigned int op, unsigned int flags, asmlinkage long sys_getrandom(char __user *buf, size_t count, unsigned int flags); asmlinkage long sys_memfd_create(const char __user *uname_ptr, unsigned int flags); -asmlinkage long sys_bpf(int cmd, union bpf_attr __user *attr, unsigned int size); +asmlinkage long sys_bpf(int cmd, union bpf_attr __user *attr, unsigned int size, + struct bpf_common_attr __user *attr_common, unsigned int size_common); asmlinkage long sys_execveat(int dfd, const char __user *filename, const char __user *const __user *argv, const char __user *const __user *envp, int flags); diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index ae83d8649ef1c..bb38afd265132 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -975,6 +975,7 @@ enum bpf_cmd { BPF_TOKEN_CREATE, BPF_PROG_STREAM_READ_BY_FD, __MAX_BPF_CMD, + BPF_COMMON_ATTRS = 1 << 16, /* Indicate carrying bpf_common_attr. */ }; enum bpf_map_type { @@ -1474,6 +1475,13 @@ struct bpf_stack_build_id { }; }; +struct bpf_common_attr { + __u64 log_buf; + __u32 log_size; + __u32 log_level; + __u32 log_true_size; +}; + #define BPF_OBJ_NAME_LEN 16U enum { diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index a48fa86f82a7f..8d97d67e6abaa 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -6092,8 +6092,10 @@ static int prog_stream_read(union bpf_attr *attr) return ret; } -static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size) +static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, + bpfptr_t uattr_common, unsigned int size_common) { + struct bpf_common_attr common_attrs; union bpf_attr attr; int err; @@ -6107,6 +6109,18 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size) if (copy_from_bpfptr(&attr, uattr, size) != 0) return -EFAULT; + memset(&common_attrs, 0, sizeof(common_attrs)); + if (cmd & BPF_COMMON_ATTRS) { + err = bpf_check_uarg_tail_zero(uattr_common, sizeof(common_attrs), size_common); + if (err) + return err; + + cmd &= ~BPF_COMMON_ATTRS; + size_common = min_t(u32, size_common, sizeof(common_attrs)); + if (copy_from_bpfptr(&common_attrs, uattr_common, size_common) != 0) + return -EFAULT; + } + err = security_bpf(cmd, &attr, size, uattr.is_kernel); if (err < 0) return err; @@ -6239,9 +6253,10 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size) return err; } -SYSCALL_DEFINE3(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size) +SYSCALL_DEFINE5(bpf, int, cmd, union bpf_attr __user *, uattr, unsigned int, size, + struct bpf_common_attr __user *, uattr_common, unsigned int, size_common) { - return __sys_bpf(cmd, USER_BPFPTR(uattr), size); + return __sys_bpf(cmd, USER_BPFPTR(uattr), size, USER_BPFPTR(uattr_common), size_common); } static bool syscall_prog_is_valid_access(int off, int size, @@ -6272,7 +6287,7 @@ BPF_CALL_3(bpf_sys_bpf, int, cmd, union bpf_attr *, attr, u32, attr_size) default: return -EINVAL; } - return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size); + return __sys_bpf(cmd, KERNEL_BPFPTR(attr), attr_size, KERNEL_BPFPTR(NULL), 0); } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index ae83d8649ef1c..bb38afd265132 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -975,6 +975,7 @@ enum bpf_cmd { BPF_TOKEN_CREATE, BPF_PROG_STREAM_READ_BY_FD, __MAX_BPF_CMD, + BPF_COMMON_ATTRS = 1 << 16, /* Indicate carrying bpf_common_attr. */ }; enum bpf_map_type { @@ -1474,6 +1475,13 @@ struct bpf_stack_build_id { }; }; +struct bpf_common_attr { + __u64 log_buf; + __u32 log_size; + __u32 log_level; + __u32 log_true_size; +}; + #define BPF_OBJ_NAME_LEN 16U enum { -- 2.51.0