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 6FFD53858D35 for ; Wed, 29 Sep 2021 01:12:52 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 6FFD53858D35 Received: from mail-ua1-f71.google.com (mail-ua1-f71.google.com [209.85.222.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-366-Ztjnja0XMRG3wuKbrAKn-w-1; Tue, 28 Sep 2021 21:12:50 -0400 X-MC-Unique: Ztjnja0XMRG3wuKbrAKn-w-1 Received: by mail-ua1-f71.google.com with SMTP id k17-20020ab04d51000000b002c056f4f643so390460uag.21 for ; Tue, 28 Sep 2021 18:12:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=4E5QeT+Jju9/3X4Sxu3cQt5nPKFLYtLK2vHTyqtYZ7s=; b=VDLGQ0OfxJllgRsVXgRPwr7+u9rhBs0uSuGEW1G9YBbaSqhy71ZWT4lWEObz/IX9Lh plojZiJ0a9oZCztUmELqM/HnFZIqJxlp/T4bXCoty5x1vdYKT2UNo+OuWVObepeAuTxD xQOZ7Wo+hm4rQpTsBrrgklNpi8TOEkIpO7voeT0NaM/8yuMgSEJxC7QwXQ+5BZbuSnuY 0DJ4V41cFbG69rH2rWRwklpTYRXGquXefz2ethaWBCqJRDjgN9S54NtWsSkf1+XULoeP ybQfSAw/wckziAw59wV/bB4WQGn6RvqiiqyV5vxfdoV3vwTkor6V122NYznY/0fMC1Yn YpGw== X-Gm-Message-State: AOAM533cHxjexm16ZTQCoXXBGVrPMkeLd8pYqWzsecrtU6QyBkVw1035 5cS8GnxWEPJVyWRmDnNkQFYd2sSTHH66w8/+I84oWR8YtfBce1Efzh13wO+ae9vCUevxz9j4Bsv HU4VoGPW2btPCbRlU6hlVaWAwYjDVOSoiFkp2 X-Received: by 2002:a05:6102:528:: with SMTP id m8mr8617699vsa.43.1632877969143; Tue, 28 Sep 2021 18:12:49 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzCtO9rBWf/VsUFEh7EYtSWlg5wH4iutlV2oqeSN6dTVwFQkSxLnFZlAF6+vVNHEsNl5hOdUtCvDxuVc9oJyKA= X-Received: by 2002:a05:6102:528:: with SMTP id m8mr8617637vsa.43.1632877967968; Tue, 28 Sep 2021 18:12:47 -0700 (PDT) MIME-Version: 1.0 References: <6d314528-224a-3e5e-2d4b-070ea776823d@polymtl.ca> <20210819022227.62623-1-amerey@redhat.com> In-Reply-To: <20210819022227.62623-1-amerey@redhat.com> From: Aaron Merey Date: Tue, 28 Sep 2021 21:12:37 -0400 Message-ID: Subject: Re: [PATCH 2/3] gdb: Add soname to build-id mapping for corefiles To: Aaron Merey Cc: lsix@lancelotsix.com, Simon Marchi , Tom Tromey , gdb-patches@sourceware.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-12.4 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, KAM_SHORT, 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: Wed, 29 Sep 2021 01:12:55 -0000 Ping. Thanks, Aaron On Wed, Aug 18, 2021 at 10:22 PM Aaron Merey via Gdb-patches wrote: > > Hi Lancelot and Simon, > > Thanks for the reviews. The updated patch is included below. > > On Tue, Aug 17, 2021 at 9:59 AM Simon Marchi wr= ote: > >>> + /* Check that bfd is an ET_DYN ELF file. */ > >>> + bfd_check_format (abfd.get (), bfd_object); > > > > I asked this in my previous review, still applies here: > > > > What's the point of calling bfd_check_format without checking the > > result? It looks like a function without side-effects. > > I included a few comments in the [PATCH 0/3] email for this series[1]. > I mentioned that for some reason bfd_check_format appears to update > the bfd 'flags' field with the correct value. If bfd_check_format is not > called here the check for the DYNAMIC flag fails even for ET_DYN files. > > [1] https://sourceware.org/pipermail/gdb-patches/2021-August/181416.html > > --- > gdb/arch-utils.c | 15 +++++---------- > gdb/arch-utils.h | 23 +++++++++++++---------- > gdb/build-id.h | 2 ++ > gdb/corelow.c | 13 ++++++++++++- > gdb/gdbarch.c | 2 +- > gdb/gdbarch.h | 4 ++-- > gdb/gdbarch.sh | 2 +- > gdb/linux-tdep.c | 46 ++++++++++++++++++++++++++++++++++------------ > gdb/progspace.c | 32 ++++++++++++++++++++++++++++++++ > gdb/progspace.h | 17 +++++++++++++++++ > gdb/solib.c | 35 +++++++++++++++++++++++++++++++++++ > gdb/solib.h | 5 +++++ > 12 files changed, 159 insertions(+), 37 deletions(-) > > diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c > index 862f26b6cf7..ffb32cb203f 100644 > --- a/gdb/arch-utils.c > +++ b/gdb/arch-utils.c > @@ -1075,16 +1075,11 @@ default_get_pc_address_flags (frame_info *frame, = CORE_ADDR pc) > > /* See arch-utils.h. */ > void > -default_read_core_file_mappings (struct gdbarch *gdbarch, > - struct bfd *cbfd, > - gdb::function_view > - pre_loop_cb, > - gdb::function_view - ULONGEST start, > - ULONGEST end, > - ULONGEST file_o= fs, > - const char *fil= ename)> > - loop_cb) > +default_read_core_file_mappings > + (struct gdbarch *gdbarch, > + struct bfd *cbfd, > + gdb::function_view pre_loop_cb, > + loop_cb_ftype loop_cb) > { > } > > diff --git a/gdb/arch-utils.h b/gdb/arch-utils.h > index 03e9082f6d7..2243c3fb85b 100644 > --- a/gdb/arch-utils.h > +++ b/gdb/arch-utils.h > @@ -294,15 +294,18 @@ extern ULONGEST default_type_align (struct gdbarch = *gdbarch, > extern std::string default_get_pc_address_flags (frame_info *frame, > CORE_ADDR pc); > > + > +using loop_cb_ftype =3D gdb::function_view + ULONGEST start, > + ULONGEST end, > + ULONGEST file_ofs, > + const char *filename, > + const bfd_build_id *build_= id)>; > + > /* Default implementation of gdbarch read_core_file_mappings method. */ > -extern void default_read_core_file_mappings (struct gdbarch *gdbarch, > - struct bfd *cbfd, > - gdb::function_view > - pre_loop_cb, > - gdb::function_view - ULO= NGEST start, > - ULO= NGEST end, > - ULO= NGEST file_ofs, > - con= st char *filename)> > - loop_cb); > +extern void default_read_core_file_mappings > + (struct gdbarch *gdbarch, > + struct bfd *cbfd, > + gdb::function_view pre_loop_cb, > + loop_cb_ftype loop_cb); > #endif /* ARCH_UTILS_H */ > diff --git a/gdb/build-id.h b/gdb/build-id.h > index 42f8d57ede1..3c9402ee71b 100644 > --- a/gdb/build-id.h > +++ b/gdb/build-id.h > @@ -20,8 +20,10 @@ > #ifndef BUILD_ID_H > #define BUILD_ID_H > > +#include "defs.h" > #include "gdb_bfd.h" > #include "gdbsupport/rsp-low.h" > +#include > > /* Locate NT_GNU_BUILD_ID from ABFD and return its content. */ > > diff --git a/gdb/corelow.c b/gdb/corelow.c > index eb785a08633..31af0f22584 100644 > --- a/gdb/corelow.c > +++ b/gdb/corelow.c > @@ -214,7 +214,7 @@ core_target::build_file_mappings () > /* read_core_file_mappings will invoke this lambda for each mapping > that it finds. */ > [&] (int num, ULONGEST start, ULONGEST end, ULONGEST file_ofs, > - const char *filename) > + const char *filename, const bfd_build_id *build_id) > { > /* Architecture-specific read_core_mapping methods are expected t= o > weed out non-file-backed mappings. */ > @@ -282,6 +282,16 @@ core_target::build_file_mappings () > > /* Set target_section fields. */ > m_core_file_mappings.emplace_back (start, end, sec); > + > + /* If this is a bfd of a shared library, record its soname > + and build id. */ > + if (build_id !=3D nullptr) > + { > + gdb::optional soname =3D gdb_bfd_read_elf_soname= (bfd); > + if (soname) > + current_program_space->set_cbfd_soname_build_id > + (std::move (*soname), build_id); > + } > }); > > normalize_mem_ranges (&m_core_unavailable_mappings); > @@ -305,6 +315,7 @@ core_target::close () > comments in clear_solib in solib.c. */ > clear_solib (); > > + current_program_space->clear_cbfd_soname_build_ids (); > current_program_space->cbfd.reset (nullptr); > } > > diff --git a/gdb/gdbarch.c b/gdb/gdbarch.c > index f89dcc57754..35464115039 100644 > --- a/gdb/gdbarch.c > +++ b/gdb/gdbarch.c > @@ -5411,7 +5411,7 @@ set_gdbarch_get_pc_address_flags (struct gdbarch *g= dbarch, > } > > void > -gdbarch_read_core_file_mappings (struct gdbarch *gdbarch, struct bfd *cb= fd, gdb::function_view pre_loop_cb, gdb::function_vi= ew loop_cb) > +gdbarch_read_core_file_mappings (struct gdbarch *gdbarch, struct bfd *cb= fd, gdb::function_view pre_loop_cb, gdb::function_vi= ew loop_cb) > { > gdb_assert (gdbarch !=3D NULL); > gdb_assert (gdbarch->read_core_file_mappings !=3D NULL); > diff --git a/gdb/gdbarch.h b/gdb/gdbarch.h > index 979159ba2f5..baf80580d60 100644 > --- a/gdb/gdbarch.h > +++ b/gdb/gdbarch.h > @@ -1710,8 +1710,8 @@ extern void set_gdbarch_get_pc_address_flags (struc= t gdbarch *gdbarch, gdbarch_g > > /* Read core file mappings */ > > -typedef void (gdbarch_read_core_file_mappings_ftype) (struct gdbarch *gd= barch, struct bfd *cbfd, gdb::function_view pre_loop= _cb, gdb::function_view loop_cb); > -extern void gdbarch_read_core_file_mappings (struct gdbarch *gdbarch, st= ruct bfd *cbfd, gdb::function_view pre_loop_cb, gdb:= :function_view loop_cb); > +typedef void (gdbarch_read_core_file_mappings_ftype) (struct gdbarch *gd= barch, struct bfd *cbfd, gdb::function_view pre_loop= _cb, gdb::function_view loop_cb); > +extern void gdbarch_read_core_file_mappings (struct gdbarch *gdbarch, st= ruct bfd *cbfd, gdb::function_view pre_loop_cb, gdb:= :function_view loop_cb); > extern void set_gdbarch_read_core_file_mappings (struct gdbarch *gdbarch= , gdbarch_read_core_file_mappings_ftype *read_core_file_mappings); > > extern struct gdbarch_tdep *gdbarch_tdep (struct gdbarch *gdbarch); > diff --git a/gdb/gdbarch.sh b/gdb/gdbarch.sh > index 39a99d0d5f3..c24079d34f3 100755 > --- a/gdb/gdbarch.sh > +++ b/gdb/gdbarch.sh > @@ -1210,7 +1210,7 @@ m;ULONGEST;type_align;struct type *type;type;;defau= lt_type_align;;0 > f;std::string;get_pc_address_flags;frame_info *frame, CORE_ADDR pc;frame= , pc;;default_get_pc_address_flags;;0 > > # Read core file mappings > -m;void;read_core_file_mappings;struct bfd *cbfd, gdb::function_view pre_loop_cb, gdb::function_view loop_cb;cbfd= , pre_loop_cb, loop_cb;;default_read_core_file_mappings;;0 > +m;void;read_core_file_mappings;struct bfd *cbfd, gdb::function_view pre_loop_cb, gdb::function_view loop_cb;cbfd, pre_loop_cb, loop_cb;;default_read_core_fil= e_mappings;;0 > > EOF > } > diff --git a/gdb/linux-tdep.c b/gdb/linux-tdep.c > index ae2f7c14f6d..812ca1f99bf 100644 > --- a/gdb/linux-tdep.c > +++ b/gdb/linux-tdep.c > @@ -44,6 +44,7 @@ > #include "solib-svr4.h" > > #include > +#include > > /* This enum represents the values that the user can choose when > informing the Linux kernel about which memory mappings will be > @@ -1097,16 +1098,11 @@ linux_info_proc (struct gdbarch *gdbarch, const c= har *args, > for each mapping. */ > > static void > -linux_read_core_file_mappings (struct gdbarch *gdbarch, > - struct bfd *cbfd, > - gdb::function_view > - pre_loop_cb, > - gdb::function_view - ULONGEST start, > - ULONGEST end, > - ULONGEST file_ofs= , > - const char *filen= ame)> > - loop_cb) > +linux_read_core_file_mappings > + (struct gdbarch *gdbarch, > + struct bfd *cbfd, > + gdb::function_view pre_loop_cb, > + loop_cb_ftype loop_cb) > { > /* Ensure that ULONGEST is big enough for reading 64-bit core files. = */ > gdb_static_assert (sizeof (ULONGEST) >=3D 8); > @@ -1175,6 +1171,23 @@ linux_read_core_file_mappings (struct gdbarch *gdb= arch, > if (f !=3D descend) > warning (_("malformed note - filename area is too big")); > > + const bfd_build_id *orig_build_id =3D cbfd->build_id; > + std::unordered_map vma_map; > + std::unordered_map filename_map; > + > + /* Search for solib build-ids in the core file. Each time one is foun= d, > + map the start vma of the corresponding elf header to the build-id. = */ > + for (bfd_section *sec =3D cbfd->sections; sec !=3D nullptr; sec =3D se= c->next) > + { > + cbfd->build_id =3D nullptr; > + > + if (sec->flags & SEC_LOAD > + && get_elf_backend_data (cbfd)->elf_backend_core_find_build_id > + (cbfd, (bfd_vma) sec->filepos)) > + vma_map[sec->vma] =3D cbfd->build_id; > + } > + > + cbfd->build_id =3D orig_build_id; > pre_loop_cb (count); > > for (int i =3D 0; i < count; i++) > @@ -1188,8 +1201,17 @@ linux_read_core_file_mappings (struct gdbarch *gdb= arch, > descdata +=3D addr_size; > char * filename =3D filenames; > filenames +=3D strlen ((char *) filenames) + 1; > + const bfd_build_id *build_id =3D vma_map[start]; > + > + /* Map filename to the build-id associated with this start vma, > + if such a build-id was found. Otherwise use the build-id > + already associated with this filename if it exists. */ > + if (build_id !=3D nullptr) > + filename_map[filename] =3D build_id; > + else > + build_id =3D filename_map[filename]; > > - loop_cb (i, start, end, file_ofs, filename); > + loop_cb (i, start, end, file_ofs, filename, build_id); > } > } > > @@ -1218,7 +1240,7 @@ linux_core_info_proc_mappings (struct gdbarch *gdba= rch, const char *args) > } > }, > [=3D] (int num, ULONGEST start, ULONGEST end, ULONGEST file_ofs, > - const char *filename) > + const char *filename, const bfd_build_id *build_id) > { > if (gdbarch_addr_bit (gdbarch) =3D=3D 32) > printf_filtered ("\t%10s %10s %10s %10s %s\n", > diff --git a/gdb/progspace.c b/gdb/progspace.c > index 7080bf8ee27..8b7b949d959 100644 > --- a/gdb/progspace.c > +++ b/gdb/progspace.c > @@ -17,6 +17,7 @@ > You should have received a copy of the GNU General Public License > along with this program. If not, see .= */ > > +#include "build-id.h" > #include "defs.h" > #include "gdbcmd.h" > #include "objfiles.h" > @@ -358,6 +359,37 @@ print_program_space (struct ui_out *uiout, int reque= sted) > } > } > > +/* See progspace.h. */ > + > +void > +program_space::set_cbfd_soname_build_id (std::string soname, > + const bfd_build_id *build_id) > +{ > + cbfd_soname_to_build_id[std::move (soname)] =3D build_id_to_string (bu= ild_id); > +} > + > +/* See progspace.h. */ > + > +const char * > +program_space::get_cbfd_soname_build_id (const char *soname) > +{ > + gdb_assert (soname); > + > + auto it =3D cbfd_soname_to_build_id.find (basename (soname)); > + if (it =3D=3D cbfd_soname_to_build_id.end ()) > + return nullptr; > + > + return it->second.c_str (); > +} > + > +/* See progspace.h. */ > + > +void > +program_space::clear_cbfd_soname_build_ids () > +{ > + cbfd_soname_to_build_id.clear (); > +} > + > /* Boolean test for an already-known program space id. */ > > static int > diff --git a/gdb/progspace.h b/gdb/progspace.h > index fb348ca7539..b42b3ffc4f1 100644 > --- a/gdb/progspace.h > +++ b/gdb/progspace.h > @@ -30,6 +30,7 @@ > #include "gdbsupport/safe-iterator.h" > #include > #include > +#include > > struct target_ops; > struct bfd; > @@ -324,6 +325,19 @@ struct program_space > /* Binary file diddling handle for the core file. */ > gdb_bfd_ref_ptr cbfd; > > + /* Associate a core file SONAME with BUILD_ID so that it can be retrie= ved > + with get_cbfd_soname_build_id. */ > + void set_cbfd_soname_build_id (std::string soname, > + const bfd_build_id *build_id); > + > + /* If a core file SONAME had a build-id associated with it by a previo= us > + call to set_cbfd_soname_build_id then return the build-id as a > + NULL-terminated hex string. */ > + const char *get_cbfd_soname_build_id (const char *soname); > + > + /* Clear all core file soname to build-id mappings. */ > + void clear_cbfd_soname_build_ids (); > + > /* The address space attached to this program space. More than one > program space may be bound to the same address space. In the > traditional unix-like debugging scenario, this will usually > @@ -378,6 +392,9 @@ struct program_space > /* The set of target sections matching the sections mapped into > this program space. Managed by both exec_ops and solib.c. */ > target_section_table m_target_sections; > + > + /* Mapping of a core file's library sonames to their respective build-= ids. */ > + std::unordered_map cbfd_soname_to_build_id; > }; > > /* An address space. It is used for comparing if > diff --git a/gdb/solib.c b/gdb/solib.c > index e30affbb7e7..1b99c8ab985 100644 > --- a/gdb/solib.c > +++ b/gdb/solib.c > @@ -23,6 +23,7 @@ > #include > #include "symtab.h" > #include "bfd.h" > +#include "build-id.h" > #include "symfile.h" > #include "objfiles.h" > #include "gdbcore.h" > @@ -1585,6 +1586,40 @@ gdb_bfd_scan_elf_dyntag (const int desired_dyntag,= bfd *abfd, CORE_ADDR *ptr, > return 0; > } > > +/* See solib.h. */ > + > +gdb::optional > +gdb_bfd_read_elf_soname (struct bfd *bfd) > +{ > + gdb_assert (bfd !=3D nullptr); > + > + gdb_bfd_ref_ptr abfd =3D gdb_bfd_open (bfd->filename, gnutarget); > + > + if (abfd =3D=3D nullptr) > + return {}; > + > + /* Check that bfd is an ET_DYN ELF file. */ > + bfd_check_format (abfd.get (), bfd_object); > + if (!(bfd_get_file_flags (abfd.get ()) & DYNAMIC)) > + return {}; > + > + /* Determine soname of shared library. If found map soname to build-i= d. */ > + CORE_ADDR idx; > + if (!gdb_bfd_scan_elf_dyntag (DT_SONAME, abfd.get (), &idx, nullptr)) > + return {}; > + > + struct bfd_section *dynstr =3D bfd_get_section_by_name (abfd.get (), "= .dynstr"); > + if (dynstr =3D=3D nullptr || bfd_section_size (dynstr) <=3D idx) > + return {}; > + > + /* Read the soname from the string table. */ > + gdb::byte_vector dynstr_buf; > + if (!gdb_bfd_get_full_section_contents (abfd.get (), dynstr, &dynstr_b= uf)) > + return {}; > + > + return std::string ((const char *)dynstr_buf.data () + idx); > +} > + > /* Lookup the value for a specific symbol from symbol table. Look up sy= mbol > from ABFD. MATCH_SYM is a callback function to determine whether to = pick > up a symbol. DATA is the input of this callback function. Return NU= LL > diff --git a/gdb/solib.h b/gdb/solib.h > index c50f74e06bf..51cc047463f 100644 > --- a/gdb/solib.h > +++ b/gdb/solib.h > @@ -118,6 +118,11 @@ extern CORE_ADDR gdb_bfd_lookup_symbol_from_symtab (= bfd *abfd, > extern int gdb_bfd_scan_elf_dyntag (const int desired_dyntag, bfd *abfd, > CORE_ADDR *ptr, CORE_ADDR *ptr_addr); > > +/* If BFD is an ELF shared object then attempt to return the string > + referred to by its DT_SONAME tag. */ > + > +extern gdb::optional gdb_bfd_read_elf_soname (struct bfd *b= fd); > + > /* Enable or disable optional solib event breakpoints as appropriate. *= / > > extern void update_solib_breakpoints (void); > -- > 2.31.1 >