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 21CA5C001B0 for ; Fri, 11 Aug 2023 13:47:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234069AbjHKNrD (ORCPT ); Fri, 11 Aug 2023 09:47:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52082 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229543AbjHKNrC (ORCPT ); Fri, 11 Aug 2023 09:47:02 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07BE52D72 for ; Fri, 11 Aug 2023 06:47:02 -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 8B8B864DB0 for ; Fri, 11 Aug 2023 13:47:01 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F52EC433C7; Fri, 11 Aug 2023 13:47:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1691761621; bh=DyVTLT2NItQVze876SzD7NXM5CZcYX0ABirj6tNgd4s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=upeDHgxLNvMAWBr125SeUwIkH9ZcKPCs2Ki7lPJ0bLJ0aRBaEGrLoZ5+v7436M7Qj uAUFU+Yn2I6va1UqiDedV/tOiRw4uunYEoFXFg/GDwQK1YIpNlZ71NpEYRdAjnNsVs jW8jFNRbzXOj1MTZiVuEPWR3C2kXoVBKl64BvqV+xXnsR/SB1Q79HNW77rVE3zejNI rrv988q0vV6j1OuE4JxGteYMaXONCKTBj5tN7Dq9xBDJvn3e1jpvZB2eQ9v/M+IOwt ksCtHKVujOURome8hzXz5KXQiXk2Pps3I1ATcZaP7okLfh66DCvLVrlqEp/oI91zOL pdupy2EwFPV2g== Received: by quaco.ghostprotocols.net (Postfix, from userid 1000) id B16DE404DF; Fri, 11 Aug 2023 10:46:57 -0300 (-03) Date: Fri, 11 Aug 2023 10:46:57 -0300 From: Arnaldo Carvalho de Melo To: Adrian Hunter Cc: Athira Rajeev , jolsa@kernel.org, irogers@google.com, namhyung@kernel.org, linux-perf-users@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, maddy@linux.ibm.com, kjain@linux.ibm.com, disgoel@linux.vnet.ibm.com Subject: Re: [PATCH] tools/perf: Fix dso kernel load and symbol process to correctly map dso to its long_name, type and adjust_symbols Message-ID: References: <20230811051546.70039-1-atrajeev@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Url: http://acmel.wordpress.com Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Em Fri, Aug 11, 2023 at 12:49:35PM +0300, Adrian Hunter escreveu: > On 11/08/23 08:15, Athira Rajeev wrote: > > Test "object cocde reading" fails sometimes for kernel address > > as below: > > > > Reading object code for memory address: 0xc000000000004c3c > > File is: [kernel.kallsyms] > > On file address is: 0x14c3c > > dso__data_read_offset failed > > test child finished with -1 > > ---- end ---- > > Object code reading: FAILED! > > > > Here the dso__data_read_offset fails for symbol address > > 0xc000000000004c3c. This is because, the dso long_name here > > is [kernel.kallsyms] and hence open_dso fails to open this > > file. There is an incorrect dso to map handling here. The > > key points here is: > > - dso long_name is set to [kernel.kallsyms]. This file is > > not present and hence returns error > > - DSO binary type is set to DSO_BINARY_TYPE__NOT_FOUND > > - dso adjust_symbols is set to zero > > > > In the end dso__data_read_offset() returns -1 and the address > > 0x14c3c can not be resolved. Hence the test fails. But the > > address actually maps to kernel dso > > > > # objdump -z -d --start-address=0xc000000000004c3c --stop-address=0xc000000000004cbc /home/athira/linux/vmlinux > > > > /home/athira/linux/vmlinux: file format elf64-powerpcle > > > > Disassembly of section .head.text: > > > > c000000000004c3c : > > c000000000004c3c: a6 02 9b 7d mfsrr1 r12 > > c000000000004c40: 78 13 42 7c mr r2,r2 > > c000000000004c44: 18 00 4d e9 ld r10,24(r13) > > c000000000004c48: 60 c6 4a 61 ori r10,r10,50784 > > c000000000004c4c: a6 03 49 7d mtctr r10 > > > > Fix the dso__process_kernel_symbol function to set the > > binary_type and adjust_symbols. adjust_symbols is used by > > function "map__rip_2objdump" which converts symbol start > > address to objdump address. Also set the dso long_name during > > dso__load_vmlinux function. > > > > Suggested-by: Adrian Hunter > > Signed-off-by: Athira Rajeev > > Acked-by: Adrian Hunter Thanks, applied. - Arnaldo > > --- > > Note: Found similar discussion here in thread: > > https://www.spinics.net/lists/linux-perf-users/msg06337.html > > where Adrian proposed the fix, but looks like this was > > not added to the perf. Hence addeed Suggested-by from Adrian. > > > > Additional to the fix proposed by Adrian, the patch also > > adds setting of adjust_symbols which is needed for > > map__rip_2objdump to convert symbol start to objdump address. > > > > tools/perf/util/symbol-elf.c | 2 ++ > > tools/perf/util/symbol.c | 15 ++++++++++----- > > 2 files changed, 12 insertions(+), 5 deletions(-) > > > > diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c > > index 252d26a59e64..9e7eeaf616b8 100644 > > --- a/tools/perf/util/symbol-elf.c > > +++ b/tools/perf/util/symbol-elf.c > > @@ -1440,6 +1440,8 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map, > > curr_dso->kernel = dso->kernel; > > curr_dso->long_name = dso->long_name; > > curr_dso->long_name_len = dso->long_name_len; > > + curr_dso->binary_type = dso->binary_type; > > + curr_dso->adjust_symbols = dso->adjust_symbols; > > curr_map = map__new2(start, curr_dso); > > dso__put(curr_dso); > > if (curr_map == NULL) > > diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c > > index f849f9ef68e6..3f36675b7c8f 100644 > > --- a/tools/perf/util/symbol.c > > +++ b/tools/perf/util/symbol.c > > @@ -2204,15 +2204,20 @@ int dso__load_vmlinux(struct dso *dso, struct map *map, > > if (symsrc__init(&ss, dso, symfs_vmlinux, symtab_type)) > > return -1; > > > > + /* > > + * dso__load_sym() may copy 'dso' which will result in the copies having > > + * an incorrect long name unless we set it here first. > > + */ > > + dso__set_long_name(dso, vmlinux, vmlinux_allocated); > > + if (dso->kernel == DSO_SPACE__KERNEL_GUEST) > > + dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX; > > + else > > + dso->binary_type = DSO_BINARY_TYPE__VMLINUX; > > + > > err = dso__load_sym(dso, map, &ss, &ss, 0); > > symsrc__destroy(&ss); > > > > if (err > 0) { > > - if (dso->kernel == DSO_SPACE__KERNEL_GUEST) > > - dso->binary_type = DSO_BINARY_TYPE__GUEST_VMLINUX; > > - else > > - dso->binary_type = DSO_BINARY_TYPE__VMLINUX; > > - dso__set_long_name(dso, vmlinux, vmlinux_allocated); > > dso__set_loaded(dso); > > pr_debug("Using %s for symbols\n", symfs_vmlinux); > > } > -- - Arnaldo