From: Aaron Merey <amerey@redhat.com>
To: gdb-patches@sourceware.org
Cc: Simon Marchi <simon.marchi@polymtl.ca>, Tom Tromey <tom@tromey.com>
Subject: [PING**2][PATCH 3/3] PR gdb/27570: missing support for debuginfod in core_target::build_file_mappings
Date: Mon, 18 Oct 2021 19:05:40 -0400 [thread overview]
Message-ID: <CAJDtP-R+EoVpjaPTjsTAn3QPfk0mfZUf=jNwcKsMK0Hxn5ROQw@mail.gmail.com> (raw)
In-Reply-To: <CAJDtP-S8fkPfgZLjMO2kwZ8qmomO0y==988LMwv9MDYJbiLDyw@mail.gmail.com>
Ping
Thanks,
Aaron
On Tue, Sep 28, 2021 at 9:13 PM Aaron Merey <amerey@redhat.com> wrote:
>
> Ping.
>
> Thanks,
> Aaron
>
> On Thu, Aug 12, 2021 at 12:25 AM Aaron Merey via Gdb-patches
> <gdb-patches@sourceware.org> wrote:
> >
> > 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 <unordered_map>
> > #include <unordered_set>
> > #include "gdbcmd.h"
> > @@ -229,6 +231,11 @@ core_target::build_file_mappings ()
> > canonical) pathname will be provided. */
> > gdb::unique_xmalloc_ptr<char> 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<char> 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<char> *destname)
> > +{
> > + return scoped_fd (-ENOSYS);
> > +}
> > +
> > #else
> > #include <elfutils/debuginfod.h>
> >
> > @@ -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<char> *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<char> *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<char> *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<char> 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
> >
next prev parent reply other threads:[~2021-10-18 23:05 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-12 4:24 [PATCH v3 0/3] Add debuginfod core file support Aaron Merey
2021-08-12 4:24 ` [PATCH 1/3] gdb/solib: Refactor scan_dyntag Aaron Merey
2021-08-17 13:28 ` Simon Marchi
2021-08-19 2:30 ` Aaron Merey
2021-08-12 4:24 ` [PATCH 2/3] gdb: Add soname to build-id mapping for corefiles Aaron Merey
2021-08-15 14:51 ` Lancelot SIX
2021-08-17 13:58 ` Simon Marchi
2021-08-19 2:22 ` Aaron Merey
2021-09-29 1:12 ` Aaron Merey
2021-10-18 23:06 ` [PING**2][PATCH " Aaron Merey
2021-11-03 18:12 ` [PING**3][PATCH " Aaron Merey
2021-11-04 1:32 ` [PATCH " Simon Marchi
2021-08-12 4:24 ` [PATCH 3/3] PR gdb/27570: missing support for debuginfod in core_target::build_file_mappings Aaron Merey
2021-09-29 1:13 ` Aaron Merey
2021-10-18 23:05 ` Aaron Merey [this message]
2021-11-03 18:11 ` [PING**3][PATCH " Aaron Merey
2021-11-04 1:37 ` [PATCH " Simon Marchi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAJDtP-R+EoVpjaPTjsTAn3QPfk0mfZUf=jNwcKsMK0Hxn5ROQw@mail.gmail.com' \
--to=amerey@redhat.com \
--cc=gdb-patches@sourceware.org \
--cc=simon.marchi@polymtl.ca \
--cc=tom@tromey.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).