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 C1F7AC0015E for ; Mon, 24 Jul 2023 17:49:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230458AbjGXRt5 (ORCPT ); Mon, 24 Jul 2023 13:49:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45848 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231880AbjGXRta (ORCPT ); Mon, 24 Jul 2023 13:49:30 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 732DF4686 for ; Mon, 24 Jul 2023 10:46:24 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 529366132A for ; Mon, 24 Jul 2023 17:45:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 808FAC433C8; Mon, 24 Jul 2023 17:45:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1690220723; bh=F0EIIGsmfIB+Y7QbLwduV6cHaLIhokS7WljeV8e+XkQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nT369RIaytZKoua0dAoPD1E3ysYvjzoA7UIVRcXqwLuM2p29Xx48/D7VyYYKhumdy k7BNjmgz3bmm1pcPYlKPB8dnI1+ADa9nAw2A22dv8TrStw6hi2GMp7LjhPHQ7xKd77 wlWeQgvB+Cwv35BEJXNdXF6loAJBFGtCQRNHM1oVqyHn6b0cQZOfea5DX8jsJnJkG1 QH18n5Fpu3ILSCclHpkqgMTAeuIwTLVK0/4DLxverZTT9Rmaf3yLLvCrdsq2Xd9/Uc gwbEnL7i4xzLxdznfyc70BcTJiwRgJB6s6AYTtcnvDxIgjU88HFv74nYB5NbS/7pi7 7SiuRtg09vjLQ== From: Will Deacon To: linux-kernel@vger.kernel.org Cc: kernel-team@android.com, Will Deacon , Josh Poimboeuf , John Stultz Subject: [PATCH 1/2] scripts/faddr2line: Ignore non-function symbols in readelf output Date: Mon, 24 Jul 2023 18:45:16 +0100 Message-Id: <20230724174517.15736-2-will@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20230724174517.15736-1-will@kernel.org> References: <20230724174517.15736-1-will@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Non-function symbols emitted in the readelf output can confuse the 'faddr2line' symbol size calculation, resulting in the erroneous rejection of valid offsets. This is especially prevalent when building an arm64 kernel with CONFIG_CFI_CLANG=y, where most functions are prefixed with a 32-bit data value in a '$d.n' section. For example: 447538: ffff800080014b80 548 FUNC GLOBAL DEFAULT 2 do_one_initcall 104: ffff800080014c74 0 NOTYPE LOCAL DEFAULT 2 $x.73 106: ffff800080014d30 0 NOTYPE LOCAL DEFAULT 2 $x.75 111: ffff800080014da4 0 NOTYPE LOCAL DEFAULT 2 $d.78 112: ffff800080014da8 0 NOTYPE LOCAL DEFAULT 2 $x.79 36: ffff800080014de0 200 FUNC LOCAL DEFAULT 2 run_init_process Adding a warning to do_one_initcall() results in: | WARNING: CPU: 0 PID: 1 at init/main.c:1236 do_one_initcall+0xf4/0x260 Which 'faddr2line' refuses to accept: $ ./scripts/faddr2line vmlinux do_one_initcall+0xf4/0x260 skipping do_one_initcall address at 0xffff800080014c74 due to size mismatch (0x260 != 0x224) no match for do_one_initcall+0xf4/0x260 Filter out entries from readelf that are not "FUNC" type, so that the size of a symbol is calculated as a delta to the next function address. Cc: Josh Poimboeuf Cc: John Stultz Signed-off-by: Will Deacon --- scripts/faddr2line | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/faddr2line b/scripts/faddr2line index 0e73aca4f908..60368a1cdaed 100755 --- a/scripts/faddr2line +++ b/scripts/faddr2line @@ -179,7 +179,7 @@ __faddr2line() { found=2 break fi - done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$7 == sec' | sort --key=2) + done < <(${READELF} --symbols --wide $objfile | sed 's/\[.*\]//' | ${AWK} -v sec=$sym_sec '$4 == "FUNC" && $7 == sec' | sort --key=2) if [[ $found = 0 ]]; then warn "can't find symbol: sym_name: $sym_name sym_sec: $sym_sec sym_addr: $sym_addr sym_elf_size: $sym_elf_size" -- 2.41.0.487.g6d72f3e995-goog