From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-183.mta0.migadu.com (out-183.mta0.migadu.com [91.218.175.183]) (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 50A5425C6E2 for ; Fri, 19 Sep 2025 04:43:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.183 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758256987; cv=none; b=ZwBXTVtWbtW3kQG7xlJ5RsdIDoTfm6SNE4peeNj75kndc2Lm5OKGlVj1KSIH7xOHHqcw8Ip+ZnZANRAfnXcCnTvzK3nFEV65F+gN8iONTfqpdwW82TloutSxbvTjXkU3YgBo8f1UA/d4h9/+XHXZ59/zKJdGSCqH7oZYn8irsWk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1758256987; c=relaxed/simple; bh=76gIooNCMMFT65DrAPDmLLeJsGB+uzG/0Y2buyJ79io=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=MRWJcE9fo83le8wiEpObs71nq/0seGfF3Q+NCOxKwU9xw87K1O6OlBUQ5E0ML8U4d7qPoufpmnDEKfur3cuWMRjy2aCoxuEzeYHuOjIfIBKYxt3UIRTlDfrXWVv4fBaO6LXUzjwlb+BI5m5Gc9+tt1oWegt5FidRBpt2XRKZZbM= 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=Lw4nDDBq; arc=none smtp.client-ip=91.218.175.183 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="Lw4nDDBq" 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=1758256980; 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=/rZm4778+NvLdi8Qqm5FqTQz+ZBqAxcQ0+8C+HJ9KIs=; b=Lw4nDDBqJYUsUllO8yGP9nyHIHyR4fRESdKgt7qD6zm/1NY3+moisMq98TQ5jbJTFi17f7 twZcDxfnkmJd4ixNlYZA7XBwDg3Y1F6rWJLUPSkYZsXDKBeZTud3EVhSExFma9E9OfLl+v HFez99jL78oAFrP5Yupys4oV8IIt8qs= 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, chen.dylane@linux.dev, leon.hwang@linux.dev, kernel-patches-bot@fb.com Subject: [PATCH bpf-next v4 1/2] bpf: Allow union argument in trampoline based programs Date: Fri, 19 Sep 2025 12:41:09 +0800 Message-ID: <20250919044110.23729-2-leon.hwang@linux.dev> In-Reply-To: <20250919044110.23729-1-leon.hwang@linux.dev> References: <20250919044110.23729-1-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 The function release_pages arg0 type UNION is unsupported. The type of the 'release_pages' arg0 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