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 X-Spam-Level: X-Spam-Status: No, score=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D33AC433B4 for ; Wed, 7 Apr 2021 19:51:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 11C1861159 for ; Wed, 7 Apr 2021 19:51:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1355733AbhDGTvp (ORCPT ); Wed, 7 Apr 2021 15:51:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:45784 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345736AbhDGTvp (ORCPT ); Wed, 7 Apr 2021 15:51:45 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8D9AB610A4; Wed, 7 Apr 2021 19:51:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1617825095; bh=VzFA9I2C0CYUWhztVXg4L5zMRzkxsAqEzsg1FbeHjjU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=aL3N2w7MZLtMl+NYyZDbCNNJoBFrGOpFxpNau/HFm5Jbj01weYZsw8IjKwcPKXuZi 0XqLHEnELZCOpIFbiFolJ/5M6UEGoRgMR52dhbFTZ65CqGgaW9x4aCMvYHRgHoUyHq lTaCo4X+4qIsKh/pQ6KekQ+g1ESE7Zg9tV0uC21W3pDwxqC1zJXjclCrt1AEHHOlRd P5e5a8EEDRk04wNysHoN1p5za4ouGER+JMESJ1Ynz2VEkXPAwzSiryXfJem3OcT6K+ LkByX7+qAEQdt+/1qSp/m8WoQExPFglnAlyq2LlJM9vRFXSgETNnmtWrIb9VPEWjok tJ5baXOsxknvA== Date: Wed, 7 Apr 2021 12:51:30 -0700 From: Nathan Chancellor To: Nick Desaulniers Cc: Peter Oberparleiter , linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Andrew Morton , Fangrui Song , Prasad Sodagudi , stable@vger.kernel.org Subject: Re: [PATCH 1/2] gcov: re-fix clang-11+ support Message-ID: <20210407195130.bacppddzyjs56qxi@archlinux-ax161> References: <20210407185456.41943-1-ndesaulniers@google.com> <20210407185456.41943-2-ndesaulniers@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210407185456.41943-2-ndesaulniers@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 07, 2021 at 11:54:55AM -0700, Nick Desaulniers wrote: > LLVM changed the expected function signature for > llvm_gcda_emit_function() in the clang-11 release. Users of clang-11 or > newer may have noticed their kernels producing invalid coverage > information: > > $ llvm-cov gcov -a -c -u -f -b .gcda -- gcno=.gcno > 1 : checksum mismatch, \ > (, ) != (, ) > 2 Invalid .gcda File! > ... > > Fix up the function signatures so calling this function interprets its > parameters correctly and computes the correct cfg checksum. In > particular, in clang-11, the additional checksum is no longer optional. > > Link: https://reviews.llvm.org/rG25544ce2df0daa4304c07e64b9c8b0f7df60c11d > Cc: stable@vger.kernel.org #5.4+ > Reported-by: Prasad Sodagudi > Tested-by: Prasad Sodagudi > Signed-off-by: Nick Desaulniers Reviewed-by: Nathan Chancellor > --- > kernel/gcov/clang.c | 38 +++++++++++++++++++++++++++++++++----- > 1 file changed, 33 insertions(+), 5 deletions(-) > > diff --git a/kernel/gcov/clang.c b/kernel/gcov/clang.c > index d41f5ecda9db..1747204541bf 100644 > --- a/kernel/gcov/clang.c > +++ b/kernel/gcov/clang.c > @@ -69,7 +69,9 @@ struct gcov_fn_info { > > u32 ident; > u32 checksum; > +#if CONFIG_CLANG_VERSION < 110000 > u8 use_extra_checksum; > +#endif > u32 cfg_checksum; > > u32 num_counters; > @@ -111,6 +113,7 @@ void llvm_gcda_start_file(const char *orig_filename, u32 version, u32 checksum) > } > EXPORT_SYMBOL(llvm_gcda_start_file); > > +#if CONFIG_CLANG_VERSION < 110000 > void llvm_gcda_emit_function(u32 ident, u32 func_checksum, > u8 use_extra_checksum, u32 cfg_checksum) > { > @@ -126,6 +129,21 @@ void llvm_gcda_emit_function(u32 ident, u32 func_checksum, > info->cfg_checksum = cfg_checksum; > list_add_tail(&info->head, ¤t_info->functions); > } > +#else > +void llvm_gcda_emit_function(u32 ident, u32 func_checksum, u32 cfg_checksum) > +{ > + struct gcov_fn_info *info = kzalloc(sizeof(*info), GFP_KERNEL); > + > + if (!info) > + return; > + > + INIT_LIST_HEAD(&info->head); > + info->ident = ident; > + info->checksum = func_checksum; > + info->cfg_checksum = cfg_checksum; > + list_add_tail(&info->head, ¤t_info->functions); > +} > +#endif > EXPORT_SYMBOL(llvm_gcda_emit_function); > > void llvm_gcda_emit_arcs(u32 num_counters, u64 *counters) > @@ -256,11 +274,16 @@ int gcov_info_is_compatible(struct gcov_info *info1, struct gcov_info *info2) > !list_is_last(&fn_ptr2->head, &info2->functions)) { > if (fn_ptr1->checksum != fn_ptr2->checksum) > return false; > +#if CONFIG_CLANG_VERSION < 110000 > if (fn_ptr1->use_extra_checksum != fn_ptr2->use_extra_checksum) > return false; > if (fn_ptr1->use_extra_checksum && > fn_ptr1->cfg_checksum != fn_ptr2->cfg_checksum) > return false; > +#else > + if (fn_ptr1->cfg_checksum != fn_ptr2->cfg_checksum) > + return false; > +#endif > fn_ptr1 = list_next_entry(fn_ptr1, head); > fn_ptr2 = list_next_entry(fn_ptr2, head); > } > @@ -378,17 +401,22 @@ size_t convert_to_gcda(char *buffer, struct gcov_info *info) > > list_for_each_entry(fi_ptr, &info->functions, head) { > u32 i; > - u32 len = 2; > - > - if (fi_ptr->use_extra_checksum) > - len++; > > pos += store_gcov_u32(buffer, pos, GCOV_TAG_FUNCTION); > - pos += store_gcov_u32(buffer, pos, len); > +#if CONFIG_CLANG_VERSION < 110000 > + pos += store_gcov_u32(buffer, pos, > + fi_ptr->use_extra_checksum ? 3 : 2); > +#else > + pos += store_gcov_u32(buffer, pos, 3); > +#endif > pos += store_gcov_u32(buffer, pos, fi_ptr->ident); > pos += store_gcov_u32(buffer, pos, fi_ptr->checksum); > +#if CONFIG_CLANG_VERSION < 110000 > if (fi_ptr->use_extra_checksum) > pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum); > +#else > + pos += store_gcov_u32(buffer, pos, fi_ptr->cfg_checksum); > +#endif > > pos += store_gcov_u32(buffer, pos, GCOV_TAG_COUNTER_BASE); > pos += store_gcov_u32(buffer, pos, fi_ptr->num_counters * 2); > -- > 2.31.1.295.g9ea45b61b8-goog >