From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8CFAC25B0D for ; Thu, 11 Aug 2022 15:52:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236870AbiHKPwy (ORCPT ); Thu, 11 Aug 2022 11:52:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35266 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236878AbiHKPwQ (ORCPT ); Thu, 11 Aug 2022 11:52:16 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 385E89DFB3; Thu, 11 Aug 2022 08:44:07 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 74157B82156; Thu, 11 Aug 2022 15:44:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 23204C433C1; Thu, 11 Aug 2022 15:44:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1660232644; bh=zy+RadlHKf4+6wfk/N//I1iIxx7CK8Pr5EdABxD750Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jGZHlYWN5aBWIEK/HM6aPSpJGoOZq02ulHqCK0aLqM3K/xoJcyU4+MYmInPL3m1IK N9e0P8KReVldyIiozcyqo+6R4ia2QSpJJlBpa0gUAqwO9gnia1HrCDDlTSuF1zPghN mWGRgKO3uDbBaXIccOmszCesmLVpHW0GqUZIXm1CzL19MktF9eCegv1q5QehsBsM6O IvkZrB75/X5cE8QSYuGWagEM6oXfmM7WzlNwOm4CX4hFMq2q+e0pZBggz04f1uVO9X UpGvosCrP4HRvFtgPrRIiAlNyf0OVDXedtvnGOgstErwCe4EKD0AdJXFwoU2/HYgHa 9ydHaG+nWGD0g== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yonghong Song , Andrii Nakryiko , Dave Marchevsky , Alexei Starovoitov , Sasha Levin , daniel@iogearbox.net, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 5.18 14/93] libbpf: Fix an error in 64bit relocation value computation Date: Thu, 11 Aug 2022 11:41:08 -0400 Message-Id: <20220811154237.1531313-14-sashal@kernel.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220811154237.1531313-1-sashal@kernel.org> References: <20220811154237.1531313-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Yonghong Song [ Upstream commit b58b2b3a31228bd9aaed9b96e9452dafd0d46024 ] Currently, the 64bit relocation value in the instruction is computed as follows: __u64 imm = insn[0].imm + ((__u64)insn[1].imm << 32) Suppose insn[0].imm = -1 (0xffffffff) and insn[1].imm = 1. With the above computation, insn[0].imm will first sign-extend to 64bit -1 (0xffffffffFFFFFFFF) and then add 0x1FFFFFFFF, producing incorrect value 0xFFFFFFFF. The correct value should be 0x1FFFFFFFF. Changing insn[0].imm to __u32 first will prevent 64bit sign extension and fix the issue. Merging high and low 32bit values also changed from '+' to '|' to be consistent with other similar occurences in kernel and libbpf. Acked-by: Andrii Nakryiko Acked-by: Dave Marchevsky Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20220607062610.3717378-1-yhs@fb.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- tools/lib/bpf/relo_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/bpf/relo_core.c b/tools/lib/bpf/relo_core.c index f946f23eab20..80862906df3f 100644 --- a/tools/lib/bpf/relo_core.c +++ b/tools/lib/bpf/relo_core.c @@ -1025,7 +1025,7 @@ int bpf_core_patch_insn(const char *prog_name, struct bpf_insn *insn, return -EINVAL; } - imm = insn[0].imm + ((__u64)insn[1].imm << 32); + imm = (__u32)insn[0].imm | ((__u64)insn[1].imm << 32); if (res->validate && imm != orig_val) { pr_warn("prog '%s': relo #%d: unexpected insn #%d (LDIMM64) value: got %llu, exp %u -> %u\n", prog_name, relo_idx, -- 2.35.1