From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTP id 39050387740D for ; Thu, 12 Aug 2021 04:24:12 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 39050387740D 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-520-x8MXdHKHNam5Sd-q4HQLJw-1; Thu, 12 Aug 2021 00:24:10 -0400 X-MC-Unique: x8MXdHKHNam5Sd-q4HQLJw-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id F107010082E5; Thu, 12 Aug 2021 04:24:09 +0000 (UTC) Received: from localhost.localdomain.com (unknown [10.22.16.110]) by smtp.corp.redhat.com (Postfix) with ESMTP id 7146B5D9C6; Thu, 12 Aug 2021 04:24:09 +0000 (UTC) From: Aaron Merey To: gdb-patches@sourceware.org, simon.marchi@polymtl.ca, tom@tromey.com Subject: [PATCH 3/3] PR gdb/27570: missing support for debuginfod in core_target::build_file_mappings Date: Thu, 12 Aug 2021 00:24:06 -0400 Message-Id: <20210812042406.75637-4-amerey@redhat.com> In-Reply-To: <20210812042406.75637-1-amerey@redhat.com> References: <20210812042406.75637-1-amerey@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset="US-ASCII" X-Spam-Status: No, score=-13.7 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_LOW, RCVD_IN_MSPIKE_H2, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org 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: , X-List-Received-Date: Thu, 12 Aug 2021 04:24:21 -0000 Add debuginfod support to core_target::build_file_mappings and locate_exec_from_corefile_build_id to enable the downloading of missing core file executables and shared libraries. 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-id found in the core file. If there is a mismatch, print a warning and attempt to query debuginfod for the correct build of the shared library: warning: Build-id of /lib64/libc.so.6 does not match core file. Downloading XY.Z MB executable for /lib64/libc.so.6 --- gdb/corelow.c | 33 +++++++++++++ gdb/debuginfod-support.c | 46 +++++++++++++++++++ gdb/debuginfod-support.h | 16 +++++++ gdb/gcore.in | 3 ++ gdb/solib.c | 35 ++++++++++++++ .../gdb.debuginfod/fetch_src_and_symbols.exp | 25 +++++++++- 6 files changed, 156 insertions(+), 2 deletions(-) diff --git a/gdb/corelow.c b/gdb/corelow.c index 97eadceed84..2c9ea1044b7 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); @@ -416,6 +423,32 @@ locate_exec_from_corefile_build_id (bfd *abfd, int from_tty) symbol_file_add_main (bfd_get_filename (execbfd.get ()), symfile_add_flag (from_tty ? SYMFILE_VERBOSE : 0)); } + else + { + 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); + else + { + /* Successful download */ + exec_file_attach (execpath.get (), from_tty); + symbol_file_add_main (execpath.get (), + symfile_add_flag (from_tty ? + SYMFILE_VERBOSE : 0)); + } + } + } } /* See gdbcore.h. */ diff --git a/gdb/debuginfod-support.c b/gdb/debuginfod-support.c index 2d626e335a0..04b39b57f6f 100644 --- a/gdb/debuginfod-support.c +++ b/gdb/debuginfod-support.c @@ -41,6 +41,16 @@ 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); +} + #else #include @@ -194,4 +204,40 @@ 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) +{ + const char *urls_env_var = getenv (DEBUGINFOD_URLS_ENV_VAR); + if (urls_env_var == NULL || urls_env_var[0] == '\0') + 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 (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 diff --git a/gdb/debuginfod-support.h b/gdb/debuginfod-support.h index 5e5aab56e74..c29a07d2abe 100644 --- a/gdb/debuginfod-support.h +++ b/gdb/debuginfod-support.h @@ -61,4 +61,20 @@ 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 "$binary_path/@GDB_TRANSFORM_NAME@" ]; then exit 1 fi +# Prevent unnecessary debuginfod queries during core file generation. +unset DEBUGINFOD_URLS + # Initialise return code. rc=0 diff --git a/gdb/solib.c b/gdb/solib.c index 8b92cf7db53..3a7bf59e64a 100644 --- a/gdb/solib.c +++ b/gdb/solib.c @@ -49,6 +49,8 @@ #include "filesystem.h" #include "gdb_bfd.h" #include "gdbsupport/filestuff.h" +#include "gdbsupport/scoped_fd.h" +#include "debuginfod-support.h" #include "source.h" #include "cli/cli-style.h" @@ -538,6 +540,39 @@ solib_map_sections (struct so_list *so) gdb::unique_xmalloc_ptr filename (tilde_expand (so->so_name)); gdb_bfd_ref_ptr abfd (ops->bfd_open (filename.get ())); + const char *build_id_hexstr = + current_program_space->get_cbfd_soname_build_id (so->so_name); + + /* If we already have core file build-id information for this solib, + verify it matches abfd's build-id. If there is a mismatch or + the solib wasn't found, attempt to query debuginfod for + the correct solib. */ + if (build_id_hexstr != NULL) + { + bool mismatch = false; + + if (abfd != NULL && abfd->build_id != NULL) + { + std::string build_id = build_id_to_string (abfd->build_id); + if (build_id != build_id_hexstr) + { + warning (_("Build-id of %ps does not match core file."), + styled_string (file_name_style.style (), + filename.get ())); + mismatch = true; + } + } + + if (abfd == NULL || mismatch) + { + scoped_fd fd = debuginfod_exec_query ((const unsigned char*) + build_id_hexstr, + 0, so->so_name, &filename); + + if (fd.get () >= 0) + abfd = ops->bfd_open (filename.get ()); + } + } if (abfd == NULL) return 0; diff --git a/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp b/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp index 81d4791eb6d..79ec4e6f853 100644 --- a/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp +++ b/gdb/testsuite/gdb.debuginfod/fetch_src_and_symbols.exp @@ -58,6 +58,11 @@ if { [gdb_compile "$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} { @@ -109,8 +114,10 @@ proc write_dwarf_file {filename buildid {value 99}} { } } +set corefile "corefile" + proc no_url { } { - global binfile outputdir debugdir + global binfile corefile outputdir debugdir setenv DEBUGINFOD_URLS "" @@ -162,10 +169,20 @@ 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 rename -force ${binfile}2 $debugdir + + clean_restart + gdb_test "core $corefile" ".*in ?? ().*" } proc local_url { } { - global binfile outputdir db debugdir + global binfile corefile outputdir db debugdir # Find an unused port set port 7999 @@ -228,6 +245,10 @@ proc local_url { } { gdb_test "file ${binfile}_alt.o" \ ".*Reading symbols from ${binfile}_alt.o\.\.\.*" \ "file [file tail ${binfile}_alt.o]" + + # gdb should now find the executable file + clean_restart + gdb_test "core $corefile" ".*return 0.*" } set envlist \ -- 2.31.1