From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-184.mta0.migadu.com (out-184.mta0.migadu.com [91.218.175.184]) (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 4AEEA23AB87 for ; Thu, 18 Sep 2025 03:43:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.184 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758166988; cv=none; b=rVSyTZM+lceeyQ7DlIZtcof7KZbrHOQuZW+Awl3MX1Okwv5DTClp1X9VaRLHVXQhHW/9Is8Kam5SzRgE83E4hY2Usl6zubxWtgFIldF4r1nQGZKVZI9n0GNfwnJjoy0CXT6ElxOes0XxOEL8b4jQIbA8Vh47Ce2/+VYsj2TfmXI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758166988; c=relaxed/simple; bh=vVPef6q5MaQWwJ9kIZNkMvhFmP5n+5bDcWsF2Hjj+fg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=i2tAvzWz9ftq6TLtTcbF+hlmURDV5b05dBz7wyxX7v65p3A/cmxU1fKQS64D3KbWlr6TnERR/yM1DPxSxXf0gm5/HMw2GDdjnMX7h6iPFUd2AsZ+nv9i8ptupsBmwlK/9c/aIVXxIl9K34guoLKEm3XitSCST/4Im5qjKBcxXXw= 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=fOnq56Cl; arc=none smtp.client-ip=91.218.175.184 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="fOnq56Cl" 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=1758166983; 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=g+IALbvYxSQwSrG+EOtHvU5OvxTvawaOAoWZ11cqxYM=; b=fOnq56ClJk4H9vkBOn6L6mLtEX/+xmwBahsfT0KjqXLD7KvBjzZu5E41MMu3v2O5jXJsCH zXAv9X65XiY2CwG3P4e2F9WurlzGWrB/2ALDKmA7GqXg57jz8Z7LekFbTERHEzwAJBH7KJ GSR/fNgp9g8khtZUwLNdOwF8ESu7bfo= From: Leon Hwang To: bpf@vger.kernel.org Cc: ast@kernel.org, andrii@kernel.org, daniel@iogearbox.net, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, ameryhung@gmail.com, menglong8.dong@gmail.com, leon.hwang@linux.dev, kernel-patches-bot@fb.com Subject: [PATCH bpf-next v3 1/2] bpf: Allow union argument in trampoline based programs Date: Thu, 18 Sep 2025 11:42:42 +0800 Message-ID: <20250918034243.205940-2-leon.hwang@linux.dev> In-Reply-To: <20250918034243.205940-1-leon.hwang@linux.dev> References: <20250918034243.205940-1-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 Currently, functions with 'union' arguments cannot be traced with fentry/fexit: bpftrace -e 'fentry:release_pages { exit(); }' -v AST node count: 6 Attaching 1 probe... ERROR: Error loading BPF program for fentry_vmlinux_release_pages_1. Kernel error log: The function release_pages arg0 type UNION is unsupported. processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0 ERROR: Loading BPF object(s) failed. The type of the 'release_pages' argument is defined as: typedef union { struct page **pages; struct folio **folios; struct encoded_page **encoded_pages; } release_pages_arg __attribute__ ((__transparent_union__)); This patch relaxes the restriction by allowing function arguments of type 'union' to be traced in verifier. Reviewed-by: Amery Hung Signed-off-by: Leon Hwang --- include/linux/bpf.h | 2 +- kernel/bpf/btf.c | 8 ++++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 41f776071ff5..42242e238757 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1113,7 +1113,7 @@ struct bpf_prog_offload { */ #define MAX_BPF_FUNC_REG_ARGS 5 -/* The argument is a structure. */ +/* The argument is a structure or a union. */ #define BTF_FMODEL_STRUCT_ARG BIT(0) /* The argument is signed. */ diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index 64739308902f..bfd83e9e7979 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -6762,7 +6762,7 @@ bool btf_ctx_access(int off, int size, enum bpf_access_type type, /* skip modifiers */ while (btf_type_is_modifier(t)) t = btf_type_by_id(btf, t->type); - if (btf_type_is_small_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) + if (btf_type_is_small_int(t) || btf_is_any_enum(t) || btf_type_is_struct(t)) /* accessing a scalar */ return true; if (!btf_type_is_ptr(t)) { @@ -7334,7 +7334,7 @@ static int __get_type_size(struct btf *btf, u32 btf_id, if (btf_type_is_ptr(t)) /* kernel size of pointer. Not BPF's size of pointer*/ return sizeof(void *); - if (btf_type_is_int(t) || btf_is_any_enum(t) || __btf_type_is_struct(t)) + if (btf_type_is_int(t) || btf_is_any_enum(t) || btf_type_is_struct(t)) return t->size; return -EINVAL; } @@ -7343,7 +7343,7 @@ static u8 __get_type_fmodel_flags(const struct btf_type *t) { u8 flags = 0; - if (__btf_type_is_struct(t)) + if (btf_type_is_struct(t)) flags |= BTF_FMODEL_STRUCT_ARG; if (btf_type_is_signed_int(t)) flags |= BTF_FMODEL_SIGNED_ARG; @@ -7384,7 +7384,7 @@ int btf_distill_func_proto(struct bpf_verifier_log *log, return -EINVAL; } ret = __get_type_size(btf, func->type, &t); - if (ret < 0 || __btf_type_is_struct(t)) { + if (ret < 0 || btf_type_is_struct(t)) { bpf_log(log, "The function %s return type %s is unsupported.\n", tname, btf_type_str(t)); -- 2.51.0