From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f201.google.com (mail-pl1-f201.google.com [209.85.214.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A3361160 for ; Fri, 23 Jun 2023 00:11:48 +0000 (UTC) Received: by mail-pl1-f201.google.com with SMTP id d9443c01a7336-1b6681255d6so156505ad.2 for ; Thu, 22 Jun 2023 17:11:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1687479108; x=1690071108; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=vo1O88LBn12GePGGmuhdEP/k87jpAuHnXHVbobu4PRQ=; b=QksAuYQ4h9HkiWUUDuUJe286BNS/KxSd9WfVtRDqdPoNN9R3SdorrFx4XiozyaaNG7 Rb8GIkwqVwR0lMbldf+pOEFtxPakHz9Zizvom7UKdoWLLi5HCtAoIBcbLhEu3x7JI0EF q8YmN9W2MVTs0f/67FbgxFfm1i6YOJ+ynwnLsu8VEVI+ARdpUGz0vXwxmVY/DdPJyU4j CXoSh0ehZHdwKxkNmjS0wQ/6y+KuhZsG0uXdbaVwWahEY/HgR6pc23egaX89uG1CExlM CV0acJV5vk2D9HpYijnsHbuCykfCGu6WCWzCrk7XS0hUlZAy85YXtaRPg8jD8qGp6BRs OCiA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687479108; x=1690071108; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=vo1O88LBn12GePGGmuhdEP/k87jpAuHnXHVbobu4PRQ=; b=Z2nDnuTuCbnoFbjdNFWdx0RXrqw49SUXJgy/FC5NLXGtT+PKcEPiiqGZK+UleYRxBA Eor5Uvc1/zRkdKB6g7D8G0g6hBEbJOGwHlc+KylQL6iMnu6gsroAAEOrotEdx8hYbzCv lF6OC9HiSWE0DF0BLCgqoHKSfd/oK9Nguq9w8Sj+O1+jui/oChU5EKfX0N+Qfw4lykY0 /9oxNtmMWm4lpbCzdaD4wcBSVBNrerYDhDbV9+DhFCGch0Qw0ejGHAzWBqX6l/sjVb2b 0Af0ld5RxFzWvqNqUPQOUNtiyZqZe4LJ0JvGbvM+E7JhaUsTvVEEwYZm+hVkq6fHX4t1 JKkw== X-Gm-Message-State: AC+VfDyN87KgzLzqyvC8gDjSlFu9vPOW32OAf639+LVviBCTi9lUeKvG 0zewQiFI0CK9ha/6Q64rgi8sEGKuvx8m66HKhe0= X-Google-Smtp-Source: ACHHUZ4OnEboURrAFGT5NncSVmStBjl8m7dSDlpD9av6g2qjlhgFEguEOrde8Lesqms2juJvliUkzAJKrOlFaDLLv14= X-Received: from samitolvanen.c.googlers.com ([fda3:e722:ac3:cc00:7f:e700:c0a8:4f92]) (user=samitolvanen job=sendgmr) by 2002:a17:902:f811:b0:1a2:3436:4119 with SMTP id ix17-20020a170902f81100b001a234364119mr2901699plb.8.1687479108018; Thu, 22 Jun 2023 17:11:48 -0700 (PDT) Date: Fri, 23 Jun 2023 00:11:43 +0000 In-Reply-To: <20230623001140.1111494-4-samitolvanen@google.com> Precedence: bulk X-Mailing-List: llvm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20230623001140.1111494-4-samitolvanen@google.com> X-Developer-Key: i=samitolvanen@google.com; a=openpgp; fpr=35CCFB63B283D6D3AEB783944CB5F6848BBC56EE X-Developer-Signature: v=1; a=openpgp-sha256; l=1491; i=samitolvanen@google.com; h=from:subject; bh=vz8JtYFBMZ6JrswVYldeog2RjlQc50BCAyUkbrZYc88=; b=owEB7QES/pANAwAKAUy19oSLvFbuAcsmYgBklOM9pyZClW2Hp8UbFrWSquBEPCjWlPQquZ198 cauUcsQF4CJAbMEAAEKAB0WIQQ1zPtjsoPW0663g5RMtfaEi7xW7gUCZJTjPQAKCRBMtfaEi7xW 7vh7C/42zRx8PHZksPRLtj/W3ew78/fa4rX9uyohW/fQWdFjU353MF0DOlLvB+HMwvd2ScZzNJc A2Q59WjNYMQI66abJdyKo53NSJaFpKE9jUguxSMEbg94h+97MmLb+I783T1xWnA9/s5XAyXy2CG 6vTmjFnSter4GgvRm/1L2a/Xr4xfsfpr2cQSe5moZKEN5w6z2SjKp/xUuvFkd6b+3Uj7t5jf7U9 Eg/3aV4wP3Ear17oOZ/56pcr7tuFb7RSWTyBcFkaoE6OUSfkk4k40eI1kwyqGaQCMdWB3YxWxjd Koe2LaCPMhC+vSRPiwMoRwSntCi02YciGfW+S7XXKUt/CazCfkNcSPcjqtOUt1Jah73z/j8PkSY ODqPGiSGUHMVQuUcKK+LHaZkpr+EKJok+pFYvu2LlREZVJeiCL0fg2q6Vro/M2AX1t2XtJH869U +eOKmEGBoBmH2K5IGBMFShQFH5V+Xtj0bo6fwZ45aW3fGOdeffsUXqNzzrS9lRYwBcIzo= X-Mailer: git-send-email 2.41.0.162.gfafddb0af9-goog Message-ID: <20230623001140.1111494-6-samitolvanen@google.com> Subject: [PATCH 2/2] kbuild: Disable GCOV for *.mod.o From: Sami Tolvanen To: Masahiro Yamada , "Peter Zijlstra (Intel)" , Kees Cook Cc: Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Tom Rix , linux-kbuild@vger.kernel.org, llvm@lists.linux.dev, linux-kernel@vger.kernel.org, Sami Tolvanen , Joe Fradley Content-Type: text/plain; charset="UTF-8" With GCOV_PROFILE_ALL, Clang injects __llvm_gcov_* functions to each object file, including the *.mod.o. As we filter out CC_FLAGS_CFI for *.mod.o, the compiler won't generate type hashes for the injected functions, and therefore indirectly calling them during module loading trips indirect call checking. Enabling CFI for *.mod.o isn't sufficient to fix this issue after commit 0c3e806ec0f9 ("x86/cfi: Add boot time hash randomization"), as *.mod.o aren't processed by objtool, which means any hashes emitted there won't be randomized. Therefore, in addition to disabling CFI for *.mod.o, also disable GCOV, as the object files don't otherwise contain any executable code. Fixes: cf68fffb66d6 ("add support for Clang CFI") Reported-by: Joe Fradley Signed-off-by: Sami Tolvanen --- scripts/Makefile.modfinal | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index 4703f652c009..fc19f67039bd 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -23,7 +23,7 @@ modname = $(notdir $(@:.mod.o=)) part-of-module = y quiet_cmd_cc_o_c = CC [M] $@ - cmd_cc_o_c = $(CC) $(filter-out $(CC_FLAGS_CFI), $(c_flags)) -c -o $@ $< + cmd_cc_o_c = $(CC) $(filter-out $(CC_FLAGS_CFI) $(CFLAGS_GCOV), $(c_flags)) -c -o $@ $< %.mod.o: %.mod.c FORCE $(call if_changed_dep,cc_o_c) -- 2.41.0.162.gfafddb0af9-goog