From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca by simark.ca with LMTP id +CLLD+p2lGEyXAAAWB0awg (envelope-from ) for ; Tue, 16 Nov 2021 22:28:42 -0500 Received: by simark.ca (Postfix, from userid 112) id 3E65D1F0C1; Tue, 16 Nov 2021 22:28:42 -0500 (EST) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on simark.ca X-Spam-Level: X-Spam-Status: No, score=-2.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RDNS_DYNAMIC,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.2 Received: from sourceware.org (ip-8-43-85-97.sourceware.org [8.43.85.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPS id 7CE6F1E813 for ; Tue, 16 Nov 2021 22:28:41 -0500 (EST) Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id D6E02385AC3B for ; Wed, 17 Nov 2021 03:28:40 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D6E02385AC3B DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1637119720; bh=ak4yr7LuRxX+r5bdi1Jr+LaaBuYYedtf0kMnDq7+yKE=; h=To:Subject:Date:In-Reply-To:References:List-Id:List-Unsubscribe: List-Archive:List-Post:List-Help:List-Subscribe:From:Reply-To:Cc: From; b=t7F2ZEH3ClwQv/bpkKkK7NhQdjTikyKrrApxWh4tzKkoVUnPwQgaQSPgfC3jMc9o2 mvpEqemmOGeCWzNtgLVEVyRcTd9zZ5ZPCLk/acBw0ppF4J9HO4tf8NW7er0Q2xCJ0g 82lhWmm5/38QODSSC2p5l6MFHb3UxefjW7pqhE/4= Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 5999E385840A for ; Wed, 17 Nov 2021 03:28:21 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 5999E385840A Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-554-xOAZIiCeMoOGyRt8VpaXgg-1; Tue, 16 Nov 2021 22:28:09 -0500 X-MC-Unique: xOAZIiCeMoOGyRt8VpaXgg-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id D1BF91808312; Wed, 17 Nov 2021 03:28:08 +0000 (UTC) Received: from localhost.localdomain.com (unknown [10.22.17.164]) by smtp.corp.redhat.com (Postfix) with ESMTP id 063AB5F4E0; Wed, 17 Nov 2021 03:28:07 +0000 (UTC) To: simon.marchi@polymtl.ca Subject: Re: [PATCH 3/3] PR gdb/27570: missing support for debuginfod in core_target::build_file_mappings Date: Tue, 16 Nov 2021 22:28:07 -0500 Message-Id: <20211117032807.719538-1-amerey@redhat.com> In-Reply-To: <500888d1-2d7d-5f55-2940-95ed5d962961@polymtl.ca> References: <500888d1-2d7d-5f55-2940-95ed5d962961@polymtl.ca> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Aaron Merey via Gdb-patches Reply-To: Aaron Merey Cc: tom@tromey.com, lsix@lancelotsix.com, gdb-patches@sourceware.org Errors-To: gdb-patches-bounces+public-inbox=simark.ca@sourceware.org Sender: "Gdb-patches" Hi Simon, I've fixed the issues you pointed out. The revised patch is below. Thanks, Aaron >From 357ffcc705057b4ed324cc39c2f5159693491fbe Mon Sep 17 00:00:00 2001 From: Aaron Merey Date: Tue, 16 Nov 2021 19:45:44 -0500 Subject: [PATCH 3/3] PR gdb/27570: missing support for debuginfod in core_target::build_file_mappings Add debuginfod support to core_target::build_file_mappings and locate_exec_from_corefile_build_id to enable the downloading of missing executables and shared libraries referenced in core files. Also add debuginfod support to solib_map_sections so that previously downloaded shared libraries can be retrieved from the debuginfod cache. When core file shared libraries are found locally, verify that their build-ids match the corresponding build-ids found in the core file. If there is a mismatch, attempt to query debuginfod for the correct build and print a warning if unsuccessful: warning: Build-id of /lib64/libc.so.6 does not match core file. Also unset the DEBUGINFOD_URLS environment variable in gcore.in to disable debuginfod when gcore invokes gdb. Debuginfo is not needed for core file generation so debuginfod queries will slow down gcore unnecessarily. --- gdb/corelow.c | 27 ++++++++++++ gdb/debuginfod-support.c | 44 +++++++++++++++++++ gdb/debuginfod-support.h | 17 +++++++ gdb/gcore.in | 3 ++ gdb/solib.c | 34 ++++++++++++++ .../gdb.debuginfod/fetch_src_and_symbols.exp | 22 ++++++++++ 6 files changed, 147 insertions(+) diff --git a/gdb/corelow.c b/gdb/corelow.c index d1256a9e99b..8141f815e39 100644 --- a/gdb/corelow.c +++ b/gdb/corelow.c @@ -46,6 +46,8 @@ #include "gdbsupport/filestuff.h" #include "build-id.h" #include "gdbsupport/pathstuff.h" +#include "gdbsupport/scoped_fd.h" +#include "debuginfod-support.h" #include #include #include "gdbcmd.h" @@ -229,6 +231,11 @@ core_target::build_file_mappings () canonical) pathname will be provided. */ gdb::unique_xmalloc_ptr expanded_fname = exec_file_find (filename, NULL); + + if (expanded_fname == nullptr && build_id != nullptr) + debuginfod_exec_query (build_id->data, build_id->size, + filename, &expanded_fname); + if (expanded_fname == nullptr) { m_core_unavailable_mappings.emplace_back (start, end - start); @@ -410,6 +417,26 @@ locate_exec_from_corefile_build_id (bfd *abfd, int from_tty) gdb_bfd_ref_ptr execbfd = build_id_to_exec_bfd (build_id->size, build_id->data); + if (execbfd == nullptr) + { + /* Attempt to query debuginfod for the executable. */ + gdb::unique_xmalloc_ptr execpath; + scoped_fd fd = debuginfod_exec_query (build_id->data, build_id->size, + abfd->filename, &execpath); + + if (fd.get () >= 0) + { + execbfd = gdb_bfd_open (execpath.get (), gnutarget); + + if (execbfd == nullptr) + warning (_("File \"%s\" from debuginfod cannot be opened as bfd"), + execpath.get ()); + else if (!build_id_verify (execbfd.get (), build_id->size, + build_id->data)) + execbfd.reset (nullptr); + } + } + if (execbfd != nullptr) { exec_file_attach (bfd_get_filename (execbfd.get ()), from_tty); diff --git a/gdb/debuginfod-support.c b/gdb/debuginfod-support.c index 2e1837da949..c4c593148b6 100644 --- a/gdb/debuginfod-support.c +++ b/gdb/debuginfod-support.c @@ -68,6 +68,15 @@ debuginfod_debuginfo_query (const unsigned char *build_id, return scoped_fd (-ENOSYS); } +scoped_fd +debuginfod_exec_query (const unsigned char *build_id, + int build_id_len, + const char *filename, + gdb::unique_xmalloc_ptr *destname) +{ + return scoped_fd (-ENOSYS); +} + #define NO_IMPL _("Support for debuginfod is not compiled into GDB.") #else @@ -256,6 +265,41 @@ debuginfod_debuginfo_query (const unsigned char *build_id, return fd; } + +/* See debuginfod-support.h */ + +scoped_fd +debuginfod_exec_query (const unsigned char *build_id, + int build_id_len, + const char *filename, + gdb::unique_xmalloc_ptr *destname) +{ + if (!debuginfod_is_enabled ()) + return scoped_fd (-ENOSYS); + + debuginfod_client *c = get_debuginfod_client (); + + if (c == nullptr) + return scoped_fd (-ENOMEM); + + char *dname = nullptr; + user_data data ("executable for", filename); + + debuginfod_set_user_data (c, &data); + scoped_fd fd (debuginfod_find_executable (c, build_id, build_id_len, &dname)); + debuginfod_set_user_data (c, nullptr); + + if (debuginfod_verbose > 0 && fd.get () < 0 && fd.get () != -ENOENT) + printf_filtered (_("Download failed: %s. " \ + "Continuing without executable for %ps.\n"), + safe_strerror (-fd.get ()), + styled_string (file_name_style.style (), filename)); + + if (fd.get () >= 0) + destname->reset (dname); + + return fd; +} #endif /* Set callback for "set debuginfod enabled". */ diff --git a/gdb/debuginfod-support.h b/gdb/debuginfod-support.h index 5e5aab56e74..7815a2f6ede 100644 --- a/gdb/debuginfod-support.h +++ b/gdb/debuginfod-support.h @@ -61,4 +61,21 @@ debuginfod_debuginfo_query (const unsigned char *build_id, const char *filename, gdb::unique_xmalloc_ptr *destname); +/* Query debuginfod servers for an executable file with BUILD_ID. + BUILD_ID can be given as a binary blob or a null-terminated string. + If given as a binary blob, BUILD_ID_LEN should be the number of bytes. + If given as a null-terminated string, BUILD_ID_LEN should be 0. + + FILENAME should be the name or path associated with the executable. + It is used for printing messages to the user. + + If the file is successfully retrieved, its path on the local machine + is stored in DESTNAME. If GDB is not built with debuginfod, this + function returns -ENOSYS. */ + +extern scoped_fd debuginfod_exec_query (const unsigned char *build_id, + int build_id_len, + const char *filename, + gdb::unique_xmalloc_ptr + *destname); #endif /* DEBUGINFOD_SUPPORT_H */ diff --git a/gdb/gcore.in b/gdb/gcore.in index 24354a79e27..25b24c3cd3d 100644 --- a/gdb/gcore.in +++ b/gdb/gcore.in @@ -89,6 +89,9 @@ if [ ! -f "$binary_path/@GDB_TRANSFORM_NAME@" ]; then exit 1 fi +# Prevent unnecessary debuginfod queries during core file generation. +unset DEBUGINFOD_URLS + # Initialise return code. rc=0 diff --git a/gdb/solib.c b/gdb/solib.c index c0beea19d7b..87a3fc0c462 100644 --- a/gdb/solib.c +++ b/gdb/solib.c @@ -49,6 +49,8 @@ #include "filesystem.h" #include "gdb_bfd.h" #include "gdbsupport/filestuff.h" +#include "gdbsupport/scoped_fd.h" +#include "debuginfod-support.h" #include "source.h" #include "cli/cli-style.h" @@ -539,6 +541,38 @@ solib_map_sections (struct so_list *so) gdb::unique_xmalloc_ptr filename (tilde_expand (so->so_name)); gdb_bfd_ref_ptr abfd (ops->bfd_open (filename.get ())); + const char *build_id_hexstr = + current_program_space->get_cbfd_soname_build_id (so->so_name); + + /* If we already know the build-id of this solib from a core file, + verify it matches abfd's build-id. If there is a mismatch or + the solib wasn't found, attempt to query debuginfod for + the correct solib. */ + if (build_id_hexstr != nullptr) + { + bool mismatch = false; + + if (abfd != nullptr && abfd->build_id != nullptr) + { + std::string build_id = build_id_to_string (abfd->build_id); + + if (build_id != build_id_hexstr) + mismatch = true; + } + + if (abfd == nullptr || mismatch) + { + scoped_fd fd = debuginfod_exec_query ((const unsigned char*) + build_id_hexstr, + 0, so->so_name, &filename); + + if (fd.get () >= 0) + abfd = ops->bfd_open (filename.get ()); + else if (mismatch) + warning (_("Build-id of %ps does not match core file."), + styled_string (file_name_style.style (), filename.get ())); + } + } if (abfd == NULL) return 0; diff --git a/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp b/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp index 757bd201b17..cfe2ae7f7da 100644 --- a/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp +++ b/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp @@ -63,6 +63,11 @@ if { [gdb_compile "$sourcetmp" "$binfile" executable {debug}] != "" } { return -1 } +if { [gdb_compile "$sourcetmp" "${binfile}2" executable {debug}] != "" } { + fail "compile" + return -1 +} + # Write some assembly that just has a .gnu_debugaltlink section. # Copied from testsuite/gdb.dwarf2/dwzbuildid.exp. proc write_just_debugaltlink {filename dwzname buildid} { @@ -114,6 +119,8 @@ proc write_dwarf_file {filename buildid {value 99}} { } } +set corefile [standard_output_file "corefile"] + proc no_url { } { global binfile outputdir debugdir @@ -167,6 +174,16 @@ proc no_url { } { gdb_test "file ${binfile}_alt.o" \ ".*could not find '.gnu_debugaltlink'.*" \ "file [file tail ${binfile}_alt.o]" + + # Generate a core file and test that gdb cannot find the executable + clean_restart ${binfile}2 + gdb_test "start" "Temporary breakpoint.*" + gdb_test "generate-core-file $::corefile" "Saved corefile $::corefile" \ + "file [file tail $::corefile] gen" + file rename -force ${binfile}2 $debugdir + + clean_restart + gdb_test "core $::corefile" ".*in ?? ().*" "file [file tail $::corefile]" } proc local_url { } { @@ -234,6 +251,11 @@ proc local_url { } { gdb_test "br main" "Breakpoint 1 at.*file.*" gdb_test "l" ".*This program is distributed in the hope.*" + # gdb should now find the executable file + clean_restart + gdb_test "core $::corefile" ".*return 0.*" "file [file tail $::corefile]" \ + "Enable debuginfod?.*" "y" + # gdb should now find the debugaltlink file clean_restart gdb_test "file ${binfile}_alt.o" \ -- 2.31.1