[v8,09/10] Validate symbol file using build-id
Commit Message
Hi,
updated for:
commit c74f7d1c6c5a968330208757f476c67a4bb66643
Author: Jon Turney <jon.turney@dronecode.org.uk>
Date: Tue Apr 7 20:49:08 2015 +0100
Allow gdb to find debug symbols file by build-id for PE file format also
Jan
Hi,
consumer part of the "build-id" attribute.
Approved by:
https://sourceware.org/ml/gdb-patches/2014-05/msg00424.html
Jan
gdb/ChangeLog
2014-02-26 Aleksandar Ristovski <aristovski@qnx.com
Jan Kratochvil <jan.kratochvil@redhat.com>
Validate symbol file using build-id.
* NEWS (Changes since GDB 7.9): Add 'set solib-build-id-force'
and 'show solib-build-id-force'. Add build-id attribute.
* solib-darwin.c (_initialize_darwin_solib): Assign validate value.
* solib-dsbt.c (_initialize_dsbt_solib): Ditto.
* solib-frv.c (_initialize_frv_solib): Ditto.
* solib-spu.c (set_spu_solib_ops): Ditto.
* solib-svr4.c: Include rsp-low.h.
(NOTE_GNU_BUILD_ID_NAME): New define.
(svr4_validate): New function.
(svr4_copy_library_list): Duplicate field build_id.
(library_list_start_library): Parse 'build-id' attribute.
(svr4_library_attributes): Add 'build-id' attribute.
(_initialize_svr4_solib): Assign validate value.
* solib-target.c (solib.h): Include.
(_initialize_solib_target): Assign validate value.
* solib.c (solib_build_id_force, show_solib_build_id_force): New.
(solib_map_sections): Use ops->validate.
(clear_so): Free build_id.
(default_solib_validate): New function.
(_initialize_solib): Add "solib-build-id-force".
* solib.h (default_solib_validate): New declaration.
* solist.h (struct so_list): New fields 'build_idsz' and 'build_id'.
(target_so_ops): New field 'validate'.
gdb/doc/ChangeLog
2014-03-02 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.texinfo (Files): Add 'set solib-build-id-force'
and 'show solib-build-id-force'.
---
gdb/NEWS | 12 +++++++
gdb/doc/gdb.texinfo | 38 ++++++++++++++++++++++
gdb/solib-darwin.c | 1 +
gdb/solib-dsbt.c | 1 +
gdb/solib-frv.c | 1 +
gdb/solib-spu.c | 1 +
gdb/solib-svr4.c | 90 +++++++++++++++++++++++++++++++++++++++++++++++++++++
gdb/solib-target.c | 2 ++
gdb/solib.c | 62 +++++++++++++++++++++++++++++++++++-
gdb/solib.h | 4 +++
gdb/solist.h | 21 +++++++++++++
11 files changed, 232 insertions(+), 1 deletion(-)
Comments
FWIW, looks good to me.
Minor thing: it seems you did not put space before the comment block, but
in the practice most of such blocks are separated by an empty line from
the previous.
Example:
...
}
+/* Boolean for command 'set solib-build-id-force'. */
...
Thanks,
Aleksandar Ristovski
QNX Software Systems
On Mon, 22 Jun 2015 14:55:14 +0200, Aleksandar Ristovski wrote:
> Minor thing: it seems you did not put space before the comment block, but
> in the practice most of such blocks are separated by an empty line from
> the previous.
> Example:
> ...
> }
> +/* Boolean for command 'set solib-build-id-force'. */
> ...
I guess it is some mail reading problem. The patch is:
1: }\n
2: \n
3:+/* Boolean for command 'set solib-build-id-force'. */\n
4:+static int solib_build_id_force = 0;\n
5:+\n
6:+/* Implement 'show solib-build-id-force'. */\n
7:+\n
8:+static void\n
I believe you ask about the empty line 2 - but that one is there.
The missing empty line between lines 3 and 4 and the present empty line 7 are
conforming to:
https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards
Jan
On 2015-06-22, 4:37 PM, "Jan Kratochvil" <jan.kratochvil@redhat.com> wrote:
>On Mon, 22 Jun 2015 14:55:14 +0200, Aleksandar Ristovski wrote:
>> Minor thing: it seems you did not put space before the comment block,
>>but
>> in the practice most of such blocks are separated by an empty line from
>> the previous.
>> Example:
>> ...
>> }
>> +/* Boolean for command 'set solib-build-id-force'. */
>> ...
>
>I guess it is some mail reading problem. The patch is:
>
>1: }\n
>2: \n
^^^^^^^^
This one appeared to be missing when I viewed the patch, apparently due to
the viewer.
Thanks,
Aleksandar
On Sun, Jun 21, 2015 at 5:16 AM, Jan Kratochvil
<jan.kratochvil@redhat.com> wrote:
> Hi,
>
> updated for:
> commit c74f7d1c6c5a968330208757f476c67a4bb66643
> Author: Jon Turney <jon.turney@dronecode.org.uk>
> Date: Tue Apr 7 20:49:08 2015 +0100
> Allow gdb to find debug symbols file by build-id for PE file format also
>
>
> Jan
>
>
> ---------- Forwarded message ----------
> From: Jan Kratochvil <jan.kratochvil@redhat.com>
> To:
> Cc:
> Date: Sun, 21 Jun 2015 11:51:52 +0200
> Subject: [PATCH 1/2] Validate symbol file using build-id
> Hi,
>
> consumer part of the "build-id" attribute.
>
> Approved by:
> https://sourceware.org/ml/gdb-patches/2014-05/msg00424.html
>
>
> Jan
>
>
> gdb/ChangeLog
> 2014-02-26 Aleksandar Ristovski <aristovski@qnx.com
> Jan Kratochvil <jan.kratochvil@redhat.com>
>
> Validate symbol file using build-id.
> * NEWS (Changes since GDB 7.9): Add 'set solib-build-id-force'
> and 'show solib-build-id-force'. Add build-id attribute.
> * solib-darwin.c (_initialize_darwin_solib): Assign validate value.
> * solib-dsbt.c (_initialize_dsbt_solib): Ditto.
> * solib-frv.c (_initialize_frv_solib): Ditto.
> * solib-spu.c (set_spu_solib_ops): Ditto.
> * solib-svr4.c: Include rsp-low.h.
> (NOTE_GNU_BUILD_ID_NAME): New define.
> (svr4_validate): New function.
> (svr4_copy_library_list): Duplicate field build_id.
> (library_list_start_library): Parse 'build-id' attribute.
> (svr4_library_attributes): Add 'build-id' attribute.
> (_initialize_svr4_solib): Assign validate value.
> * solib-target.c (solib.h): Include.
> (_initialize_solib_target): Assign validate value.
> * solib.c (solib_build_id_force, show_solib_build_id_force): New.
> (solib_map_sections): Use ops->validate.
> (clear_so): Free build_id.
> (default_solib_validate): New function.
> (_initialize_solib): Add "solib-build-id-force".
> * solib.h (default_solib_validate): New declaration.
> * solist.h (struct so_list): New fields 'build_idsz' and 'build_id'.
> (target_so_ops): New field 'validate'.
>
> gdb/doc/ChangeLog
> 2014-03-02 Jan Kratochvil <jan.kratochvil@redhat.com>
>
> * gdb.texinfo (Files): Add 'set solib-build-id-force'
> and 'show solib-build-id-force'.
IIUC this applies to symbol files (the main program) too, right?
If so, having solib in the option name is confusing.
set build-id-force
or
set require-build-id-match
or some such would be clearer.
> diff --git a/gdb/NEWS b/gdb/NEWS
> index 3ec5851..8cbe1fc 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -159,6 +159,12 @@ set debug linux-namespaces
> show debug linux-namespaces
> Control display of debugging info regarding Linux namespaces.
>
> +set solib-build-id-force (on|off)
> +show solib-build-id-force
> + Inferior shared library and symbol file may contain unique build-id.
> + If both build-ids are present but they do not match then this setting
> + enables (on) or disables (off) loading of such symbol file.
> +
> * The command 'thread apply all' can now support new option '-ascending'
> to call its specified command for all threads in ascending order.
>
> @@ -233,6 +239,12 @@ fork-events and vfork-events features in qSupported
> * GDB now supports access to vector registers on S/390 GNU/Linux
> targets.
>
> +* New features in the GDB remote stub, GDBserver
> +
> + ** library-list-svr4 contains also optional attribute 'build-id' for
> + each library. GDB does not load library with build-id that
> + does not match such attribute.
> +
> * Removed command line options
>
> -xdb HP-UX XDB compatibility mode.
> diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
> index 1460b7f..f7e4405 100644
> --- a/gdb/doc/gdb.texinfo
> +++ b/gdb/doc/gdb.texinfo
> @@ -17912,6 +17912,44 @@ libraries that were loaded by explicit user requests are not
> discarded.
> @end table
>
> +@table @code
> +@kindex set solib-build-id-force
> +@cindex override @value{GDBN} build-id check
> +@item set solib-build-id-force @var{mode}
> +Setting to override @value{GDBN} build-id check.
> +
> +Inferior shared libraries and symbol files may contain unique build-id.
> +By default @value{GDBN} will ignore symbol files with non-matching build-id
> +while printing:
> +
> +@smallexample
> + warning: Shared object "libfoo.so.1" could not be validated (remote
> + build ID 2bc1745e does not match local build ID a08f8767) and will be
> + ignored; or use 'set solib-build-id-force'.
> +@end smallexample
> +
> +Turning on this setting would load such symbol file while still printing:
> +
> +@smallexample
> + warning: Shared object "libfoo.so.1" could not be validated (remote
> + build ID 2bc1745e does not match local build ID a08f8767) but it is
> + being loaded due to 'set solib-build-id-force'.
> +@end smallexample
> +
> +If remote build-id is present but it does not match local build-id (or local
> +build-id is not present) then this setting enables (@var{mode} is @code{on}) or
> +disables (@var{mode} is @code{off}) loading of such symbol file. On systems
> +where build-id is not present in the remote system this setting has no effect.
> +The default value is @code{off}.
> +
> +Loading non-matching symbol file may confuse debugging including breakage
> +of backtrace output.
> +
> +@kindex show solib-build-id-force
> +@item show solib-build-id-force
> +Display the current mode of build-id check override.
> +@end table
> +
> Sometimes you may wish that @value{GDBN} stops and gives you control
> when any of shared library events happen. The best way to do this is
> to use @code{catch load} and @code{catch unload} (@pxref{Set
> diff --git a/gdb/solib-darwin.c b/gdb/solib-darwin.c
> index f96841f..9309c35 100644
> --- a/gdb/solib-darwin.c
> +++ b/gdb/solib-darwin.c
> @@ -634,4 +634,5 @@ _initialize_darwin_solib (void)
> darwin_so_ops.in_dynsym_resolve_code = darwin_in_dynsym_resolve_code;
> darwin_so_ops.lookup_lib_global_symbol = darwin_lookup_lib_symbol;
> darwin_so_ops.bfd_open = darwin_bfd_open;
> + darwin_so_ops.validate = default_solib_validate;
> }
> diff --git a/gdb/solib-dsbt.c b/gdb/solib-dsbt.c
> index 7da5833..9fe6533 100644
> --- a/gdb/solib-dsbt.c
> +++ b/gdb/solib-dsbt.c
> @@ -1080,6 +1080,7 @@ _initialize_dsbt_solib (void)
> dsbt_so_ops.open_symbol_file_object = open_symbol_file_object;
> dsbt_so_ops.in_dynsym_resolve_code = dsbt_in_dynsym_resolve_code;
> dsbt_so_ops.bfd_open = solib_bfd_open;
> + dsbt_so_ops.validate = default_solib_validate;
>
> /* Debug this file's internals. */
> add_setshow_zuinteger_cmd ("solib-dsbt", class_maintenance,
> diff --git a/gdb/solib-frv.c b/gdb/solib-frv.c
> index f7ef38b..b768146 100644
> --- a/gdb/solib-frv.c
> +++ b/gdb/solib-frv.c
> @@ -1183,6 +1183,7 @@ _initialize_frv_solib (void)
> frv_so_ops.open_symbol_file_object = open_symbol_file_object;
> frv_so_ops.in_dynsym_resolve_code = frv_in_dynsym_resolve_code;
> frv_so_ops.bfd_open = solib_bfd_open;
> + frv_so_ops.validate = default_solib_validate;
>
> /* Debug this file's internals. */
> add_setshow_zuinteger_cmd ("solib-frv", class_maintenance,
> diff --git a/gdb/solib-spu.c b/gdb/solib-spu.c
> index 44fbf91..d162884 100644
> --- a/gdb/solib-spu.c
> +++ b/gdb/solib-spu.c
> @@ -519,6 +519,7 @@ set_spu_solib_ops (struct gdbarch *gdbarch)
> spu_so_ops.current_sos = spu_current_sos;
> spu_so_ops.bfd_open = spu_bfd_open;
> spu_so_ops.lookup_lib_global_symbol = spu_lookup_lib_symbol;
> + spu_so_ops.validate = default_solib_validate;
> }
>
> set_solib_ops (gdbarch, &spu_so_ops);
> diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c
> index 909dfb7..b434c1f 100644
> --- a/gdb/solib-svr4.c
> +++ b/gdb/solib-svr4.c
> @@ -45,6 +45,9 @@
> #include "auxv.h"
> #include "gdb_bfd.h"
> #include "probe.h"
> +#include "rsp-low.h"
> +
> +#define NOTE_GNU_BUILD_ID_NAME ".note.gnu.build-id"
>
> static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
> static int svr4_have_link_map_offsets (void);
> @@ -970,6 +973,63 @@ svr4_keep_data_in_core (CORE_ADDR vaddr, unsigned long size)
> return (name_lm >= vaddr && name_lm < vaddr + size);
> }
>
> +/* Validate SO by comparing build-id from the associated bfd and
> + corresponding build-id from target memory. */
Please document that the result is an error message or NULL for success
(including missing build id), and that the caller must free it.
I realize you say so in the docs for the "validate" "method",
but the comment here doesn't mention it is the validate method
(which would be a fine alternative to repeating all the docs
of the method).
> +
> +static char *
> +svr4_validate (const struct so_list *const so)
> +{
> + const bfd_byte *local_id;
> + size_t local_idsz;
> +
> + gdb_assert (so != NULL);
> +
> + /* Target doesn't support reporting the build ID or the remote shared library
> + does not have build ID. */
> + if (so->build_id == NULL)
> + return NULL;
> +
> + /* Build ID may be present in the local file, just GDB is unable to retrieve
> + it. As it has been reported by gdbserver it is not FSF gdbserver. */
> + if (so->abfd == NULL
> + || !bfd_check_format (so->abfd, bfd_object))
> + return NULL;
> +
> + /* GDB has verified the local file really does not contain the build ID. */
> + if (so->abfd->build_id == NULL)
> + {
> + char *remote_hex;
> +
> + remote_hex = alloca (so->build_idsz * 2 + 1);
> + bin2hex (so->build_id, remote_hex, so->build_idsz);
> +
> + return xstrprintf (_("remote build ID is %s "
> + "but local file does not have build ID"),
> + remote_hex);
> + }
> +
> + local_id = so->abfd->build_id->data;
> + local_idsz = so->abfd->build_id->size;
> +
> + if (so->build_idsz != local_idsz
> + || memcmp (so->build_id, local_id, so->build_idsz) != 0)
> + {
> + char *remote_hex, *local_hex;
> +
> + remote_hex = alloca (so->build_idsz * 2 + 1);
> + bin2hex (so->build_id, remote_hex, so->build_idsz);
> + local_hex = alloca (local_idsz * 2 + 1);
> + bin2hex (local_id, local_hex, local_idsz);
> +
> + return xstrprintf (_("remote build ID %s "
> + "does not match local build ID %s"),
> + remote_hex, local_hex);
> + }
> +
> + /* Both build IDs are present and they match. */
> + return NULL;
> +}
> +
> /* Implement the "open_symbol_file_object" target_so_ops method.
>
> If no open symbol file, attempt to locate and open the main symbol
> @@ -1108,6 +1168,12 @@ svr4_copy_library_list (struct so_list *src)
> newobj->lm_info = xmalloc (sizeof (struct lm_info));
> memcpy (newobj->lm_info, src->lm_info, sizeof (struct lm_info));
>
> + if (newobj->build_id != NULL)
> + {
> + newobj->build_id = xmalloc (src->build_idsz);
> + memcpy (newobj->build_id, src->build_id, src->build_idsz);
> + }
> +
> newobj->next = NULL;
> *link = newobj;
> link = &newobj->next;
> @@ -1135,6 +1201,9 @@ library_list_start_library (struct gdb_xml_parser *parser,
> ULONGEST *lmp = xml_find_attribute (attributes, "lm")->value;
> ULONGEST *l_addrp = xml_find_attribute (attributes, "l_addr")->value;
> ULONGEST *l_ldp = xml_find_attribute (attributes, "l_ld")->value;
> + const struct gdb_xml_value *const att_build_id
> + = xml_find_attribute (attributes, "build-id");
> + const char *const hex_build_id = att_build_id ? att_build_id->value : NULL;
> struct so_list *new_elem;
>
> new_elem = XCNEW (struct so_list);
> @@ -1146,6 +1215,25 @@ library_list_start_library (struct gdb_xml_parser *parser,
> strncpy (new_elem->so_name, name, sizeof (new_elem->so_name) - 1);
> new_elem->so_name[sizeof (new_elem->so_name) - 1] = 0;
> strcpy (new_elem->so_original_name, new_elem->so_name);
> + if (hex_build_id != NULL)
> + {
> + const size_t hex_build_id_len = strlen (hex_build_id);
> +
> + if (hex_build_id_len > 0 && (hex_build_id_len & 1U) == 0)
> + {
> + const size_t build_idsz = hex_build_id_len / 2;
> +
> + new_elem->build_id = xmalloc (build_idsz);
> + new_elem->build_idsz = hex2bin (hex_build_id, new_elem->build_id,
> + build_idsz);
> + if (new_elem->build_idsz != build_idsz)
> + {
This happens for a malformed build id, right?
A warning would be useful here.
It'd also be nice to have a warning for an odd count.
> + xfree (new_elem->build_id);
> + new_elem->build_id = NULL;
> + new_elem->build_idsz = 0;
> + }
> + }
> + }
>
> *list->tailp = new_elem;
> list->tailp = &new_elem->next;
> @@ -1180,6 +1268,7 @@ static const struct gdb_xml_attribute svr4_library_attributes[] =
> { "lm", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
> { "l_addr", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
> { "l_ld", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
> + { "build-id", GDB_XML_AF_OPTIONAL, NULL, NULL },
> { NULL, GDB_XML_AF_NONE, NULL, NULL }
> };
>
> @@ -3258,4 +3347,5 @@ _initialize_svr4_solib (void)
> svr4_so_ops.keep_data_in_core = svr4_keep_data_in_core;
> svr4_so_ops.update_breakpoints = svr4_update_solib_event_breakpoints;
> svr4_so_ops.handle_event = svr4_handle_solib_event;
> + svr4_so_ops.validate = svr4_validate;
> }
> diff --git a/gdb/solib-target.c b/gdb/solib-target.c
> index f14363a..13cbd26 100644
> --- a/gdb/solib-target.c
> +++ b/gdb/solib-target.c
> @@ -25,6 +25,7 @@
> #include "target.h"
> #include "vec.h"
> #include "solib-target.h"
> +#include "solib.h"
>
> /* Private data for each loaded library. */
> struct lm_info
> @@ -506,6 +507,7 @@ _initialize_solib_target (void)
> solib_target_so_ops.in_dynsym_resolve_code
> = solib_target_in_dynsym_resolve_code;
> solib_target_so_ops.bfd_open = solib_bfd_open;
> + solib_target_so_ops.validate = default_solib_validate;
>
> /* Set current_target_so_ops to solib_target_so_ops if not already
> set. */
> diff --git a/gdb/solib.c b/gdb/solib.c
> index 0010c2f..4bd47d0 100644
> --- a/gdb/solib.c
> +++ b/gdb/solib.c
> @@ -523,6 +523,20 @@ solib_bfd_open (char *pathname)
> return abfd;
> }
>
> +/* Boolean for command 'set solib-build-id-force'. */
> +static int solib_build_id_force = 0;
> +
> +/* Implement 'show solib-build-id-force'. */
> +
> +static void
> +show_solib_build_id_force (struct ui_file *file, int from_tty,
> + struct cmd_list_element *c, const char *value)
> +{
> + fprintf_filtered (file, _("Loading of shared libraries "
> + "with non-matching build-id is %s.\n"),
> + value);
> +}
> +
> /* Given a pointer to one of the shared objects in our list of mapped
> objects, use the recorded name to open a bfd descriptor for the
> object, build a section table, relocate all the section addresses
> @@ -539,7 +553,7 @@ static int
> solib_map_sections (struct so_list *so)
> {
> const struct target_so_ops *ops = solib_ops (target_gdbarch ());
> - char *filename;
> + char *filename, *validate_error;
> struct target_section *p;
> struct cleanup *old_chain;
> bfd *abfd;
> @@ -555,6 +569,27 @@ solib_map_sections (struct so_list *so)
> /* Leave bfd open, core_xfer_memory and "info files" need it. */
> so->abfd = abfd;
>
> + gdb_assert (ops->validate != NULL);
> +
> + validate_error = ops->validate (so);
> + if (validate_error != NULL)
> + {
> + if (!solib_build_id_force)
> + {
> + warning (_("Shared object \"%s\" could not be validated (%s) and "
> + "will be ignored; or use 'set solib-build-id-force'."),
> + so->so_name, validate_error);
> + xfree (validate_error);
> + gdb_bfd_unref (so->abfd);
> + so->abfd = NULL;
> + return 0;
> + }
> + warning (_("Shared object \"%s\" could not be validated (%s) "
> + "but it is being loaded due to 'set solib-build-id-force'."),
> + so->so_name, validate_error);
> + xfree (validate_error);
> + }
> +
> /* Copy the full path name into so_name, allowing symbol_file_add
> to find it later. This also affects the =library-loaded GDB/MI
> event, and in particular the part of that notification providing
> @@ -631,6 +666,9 @@ clear_so (struct so_list *so)
> of the symbol file. */
> strcpy (so->so_name, so->so_original_name);
>
> + xfree (so->build_id);
> + so->build_id = NULL;
> +
> /* Do the same for target-specific data. */
> if (ops->clear_so != NULL)
> ops->clear_so (so);
> @@ -1662,6 +1700,14 @@ remove_user_added_objfile (struct objfile *objfile)
> }
> }
>
> +/* Default implementation does not perform any validation. */
> +
> +char *
> +default_solib_validate (const struct so_list *const so)
> +{
> + return NULL; /* No validation. */
> +}
> +
> extern initialize_file_ftype _initialize_solib; /* -Wmissing-prototypes */
>
> void
> @@ -1719,4 +1765,18 @@ PATH and LD_LIBRARY_PATH."),
> reload_shared_libraries,
> show_solib_search_path,
> &setlist, &showlist);
> +
> + add_setshow_boolean_cmd ("solib-build-id-force", class_support,
> + &solib_build_id_force, _("\
> +Set loading of shared libraries with non-matching build-id."), _("\
> +Show loading of shared libraries with non-matching build-id."), _("\
> +Inferior shared library and symbol file may contain unique build-id.\n\
> +If both build-ids are present but they do not match then this setting\n\
> +enables (on) or disables (off) loading of such symbol file.\n\
> +Loading non-matching symbol file may confuse debugging including breakage\n\
> +of backtrace output."),
> + NULL,
> + show_solib_build_id_force,
> + &setlist, &showlist);
> +
> }
> diff --git a/gdb/solib.h b/gdb/solib.h
> index 336971d..c3bf529 100644
> --- a/gdb/solib.h
> +++ b/gdb/solib.h
> @@ -98,4 +98,8 @@ extern void update_solib_breakpoints (void);
>
> extern void handle_solib_event (void);
>
> +/* Default validation always returns 1. */
> +
> +extern char *default_solib_validate (const struct so_list *so);
> +
> #endif /* SOLIB_H */
> diff --git a/gdb/solist.h b/gdb/solist.h
> index 7021f5c..f0d8653 100644
> --- a/gdb/solist.h
> +++ b/gdb/solist.h
> @@ -75,6 +75,22 @@ struct so_list
> There may not be just one (e.g. if two segments are relocated
> differently); but this is only used for "info sharedlibrary". */
> CORE_ADDR addr_low, addr_high;
> +
> + /* Build id in raw format, contains verbatim contents of
> + .note.gnu.build-id including note header.
Including the note header will be confusing to readers.
Is there a reason to include it?
OTOH, given the above call to hex2bin,
does this really include the note header?
> ... This is actual
> + BUILD_ID which comes either from the remote target via qXfer
> + packet or via reading target memory. Therefore, it may differ
> + from the build-id of the associated bfd. In a normal
> + scenario, this so would soon lose its abfd due to failed
> + validation.
I can't read this last sentence.
What are you trying to say here?
> + Reading target memory should be done by following execution view
> + of the binary (following program headers in the case of ELF).
> + Computing address from the linking view (following ELF section
> + headers) may give incorrect build-id memory address despite the
> + symbols still match.
> + Such an example is a prelinked vs. unprelinked i386 ELF file. */
> + size_t build_idsz;
> + gdb_byte *build_id;
> };
>
> struct target_so_ops
> @@ -168,6 +184,11 @@ struct target_so_ops
> NULL, in which case no specific preprocessing is necessary
> for this target. */
> void (*handle_event) (void);
> +
> + /* Return NULL if SO does match target SO it is supposed to
> + represent. Otherwise return string describing why it does not match.
> + Caller has to free the string. */
> + char *(*validate) (const struct so_list *so);
> };
>
> /* Free the memory associated with a (so_list *). */
> --
> 2.1.0
>
On Tue, 23 Jun 2015 00:25:52 +0200, Doug Evans wrote:
> On Sun, Jun 21, 2015 at 5:16 AM, Jan Kratochvil <jan.kratochvil@redhat.com> wrote:
> > * gdb.texinfo (Files): Add 'set solib-build-id-force'
> > and 'show solib-build-id-force'.
>
> IIUC this applies to symbol files (the main program) too, right?
No. That is an extension I am working on as an add-on patchset, to be posted
in a week or two.
I expected this "solib" patchset will be already approved a long time ago so
the add-on patchset will make sense. But given this patchset is still being
reviewed and the new patchset will change some parts of this one I am curious
whether I should not rather merge the second patchset into the first one and
start the review process from scratch.
> If so, having solib in the option name is confusing.
>
> set build-id-force
> or
> set require-build-id-match
> or some such would be clearer.
The new patchset is being cooked as the last commits without ChangeLogs at:
https://sourceware.org/git/?p=archer.git;a=log;h=refs/heads/jankratochvil/gdbserverbuildid
Particularly:
https://sourceware.org/git/?p=archer.git;a=commitdiff;h=79c03cbb287878d3e5fcfb8104bdd21aa712f013
-set solib-build-id-force (on|off)
+set build-id-force (on|off)
> > +/* Validate SO by comparing build-id from the associated bfd and
> > + corresponding build-id from target memory. */
>
> Please document that the result is an error message or NULL for success
> (including missing build id), and that the caller must free it.
> I realize you say so in the docs for the "validate" "method",
> but the comment here doesn't mention it is the validate method
> (which would be a fine alternative to repeating all the docs
> of the method).
I agree; although it gets reworked in the add-on patchset anyway.
https://sourceware.org/git/?p=archer.git;a=commitdiff;h=6d40ae1db39bdabb415a05aa909178d61cb519ed
> > +
> > +static char *
> > +svr4_validate (const struct so_list *const so)
> > @@ -1146,6 +1215,25 @@ library_list_start_library (struct gdb_xml_parser *parser,
> > strncpy (new_elem->so_name, name, sizeof (new_elem->so_name) - 1);
> > new_elem->so_name[sizeof (new_elem->so_name) - 1] = 0;
> > strcpy (new_elem->so_original_name, new_elem->so_name);
> > + if (hex_build_id != NULL)
> > + {
> > + const size_t hex_build_id_len = strlen (hex_build_id);
> > +
> > + if (hex_build_id_len > 0 && (hex_build_id_len & 1U) == 0)
> > + {
> > + const size_t build_idsz = hex_build_id_len / 2;
> > +
> > + new_elem->build_id = xmalloc (build_idsz);
> > + new_elem->build_idsz = hex2bin (hex_build_id, new_elem->build_id,
> > + build_idsz);
> > + if (new_elem->build_idsz != build_idsz)
> > + {
>
> This happens for a malformed build id, right?
Yes.
> A warning would be useful here.
> It'd also be nice to have a warning for an odd count.
OK.
> > --- a/gdb/solist.h
> > +++ b/gdb/solist.h
> > @@ -75,6 +75,22 @@ struct so_list
> > There may not be just one (e.g. if two segments are relocated
> > differently); but this is only used for "info sharedlibrary". */
> > CORE_ADDR addr_low, addr_high;
> > +
> > + /* Build id in raw format, contains verbatim contents of
> > + .note.gnu.build-id including note header.
>
> Including the note header will be confusing to readers.
> Is there a reason to include it?
It seems to simplify all the code. I will recheck how the code looks if it
parses the note.
Thanks,
Jan
On Tue, 23 Jun 2015 00:25:52 +0200, Doug Evans wrote:
> On Sun, Jun 21, 2015 at 5:16 AM, Jan Kratochvil <jan.kratochvil@redhat.com> wrote:
> > --- a/gdb/solist.h
> > +++ b/gdb/solist.h
> > @@ -75,6 +75,22 @@ struct so_list
> > There may not be just one (e.g. if two segments are relocated
> > differently); but this is only used for "info sharedlibrary". */
> > CORE_ADDR addr_low, addr_high;
> > +
> > + /* Build id in raw format, contains verbatim contents of
> > + .note.gnu.build-id including note header.
>
> Including the note header will be confusing to readers.
> Is there a reason to include it?
>
> OTOH, given the above call to hex2bin,
> does this really include the note header?
It does not, only the comment was wrong. Changed it to:
/* Build id decoded from .note.gnu.build-id without note header. This is
actual BUILD_ID which comes either from the remote target via qXfer
> > ... This is actual
> > + BUILD_ID which comes either from the remote target via qXfer
> > + packet or via reading target memory. Therefore, it may differ
> > + from the build-id of the associated bfd. In a normal
> > + scenario, this so would soon lose its abfd due to failed
> > + validation.
>
> I can't read this last sentence.
> What are you trying to say here?
It was written by Aleksandar Ristovski and I find it OK myself.
So as an explanation the process is:
1. GDB reads/receives so->build_id from GDB server.
2. GDB opens local BFD so->abfd.
3. GDB compares so->build_id with so->abfd->build_id (by ops->validate)
4. If they differ so->abfd is freed/cleared (in solib_map_sections).
Therefore could you suggest a different comment?
Thanks,
Jan
Jan Kratochvil wrote:
> +static char *
> +svr4_validate (const struct so_list *const so)
> +{
...
> + return xstrprintf (_("remote build ID is %s "
> + "but local file does not have build ID"),
> + remote_hex);
Seems odd to say "remote" here. Can't these errors trigger with native
debugging as well?
Doug Evans wrote:
>
>> > If so, having solib in the option name is confusing.
>> >
>> > set build-id-force
>> > or
>> > set require-build-id-match
>> > or some such would be clearer.
"build-id-force" sound odd to me. The latter sounds OK,
as would "set build-id-validation on/off/...".
With that, and once the previous issues raised are
addressed, I think this is good to go.
Thanks,
Pedro Alves
On Sat, Jun 27, 2015 at 4:05 PM, Jan Kratochvil
<jan.kratochvil@redhat.com> wrote:
> On Tue, 23 Jun 2015 00:25:52 +0200, Doug Evans wrote:
>> On Sun, Jun 21, 2015 at 5:16 AM, Jan Kratochvil <jan.kratochvil@redhat.com> wrote:
>> > --- a/gdb/solist.h
>> > +++ b/gdb/solist.h
>> > @@ -75,6 +75,22 @@ struct so_list
>> > There may not be just one (e.g. if two segments are relocated
>> > differently); but this is only used for "info sharedlibrary". */
>> > CORE_ADDR addr_low, addr_high;
>> > +
>> > + /* Build id in raw format, contains verbatim contents of
>> > + .note.gnu.build-id including note header.
>>
>> Including the note header will be confusing to readers.
>> Is there a reason to include it?
>>
>> OTOH, given the above call to hex2bin,
>> does this really include the note header?
>
> It does not, only the comment was wrong. Changed it to:
> /* Build id decoded from .note.gnu.build-id without note header. This is
> actual BUILD_ID which comes either from the remote target via qXfer
>
>
>> > ... This is actual
>> > + BUILD_ID which comes either from the remote target via qXfer
>> > + packet or via reading target memory. Therefore, it may differ
>> > + from the build-id of the associated bfd. In a normal
>> > + scenario, this so would soon lose its abfd due to failed
>> > + validation.
>>
>> I can't read this last sentence.
>> What are you trying to say here?
>
> It was written by Aleksandar Ristovski and I find it OK myself.
> So as an explanation the process is:
>
> 1. GDB reads/receives so->build_id from GDB server.
> 2. GDB opens local BFD so->abfd.
> 3. GDB compares so->build_id with so->abfd->build_id (by ops->validate)
> 4. If they differ so->abfd is freed/cleared (in solib_map_sections).
>
> Therefore could you suggest a different comment?
I'd be ok with just deleting the last two sentences:
This is actual
BUILD_ID which comes either from the remote target via qXfer
packet or via reading target memory.
But if you want more I'm ok with:
This is actual
BUILD_ID which comes either from the remote target via qXfer
packet or via reading target memory. Note that if there's a
mismatch with the associated bfd then so->abfd will be cleared.
On Wed, 08 Jul 2015 16:44:25 +0200, Pedro Alves wrote:
> Jan Kratochvil wrote:
>
> > +static char *
> > +svr4_validate (const struct so_list *const so)
> > +{
>
> ...
>
> > + return xstrprintf (_("remote build ID is %s "
> > + "but local file does not have build ID"),
> > + remote_hex);
>
> Seems odd to say "remote" here. Can't these errors trigger with native
> debugging as well?
For this patchset not yet. The message is changed in a later patchset being
prepared where it applies also for local files.
> Doug Evans wrote:
> >
> >> > If so, having solib in the option name is confusing.
> >> >
> >> > set build-id-force
> >> > or
> >> > set require-build-id-match
> >> > or some such would be clearer.
>
> "build-id-force" sound odd to me. The latter sounds OK,
> as would "set build-id-validation on/off/...".
OK, I will change it to "set build-id-validation on/off/...".
> With that, and once the previous issues raised are
> addressed, I think this is good to go.
There patches are left without reply:
[PATCH v7 04/10] Create empty nat/linux-maps.[ch] and common/target-utils.[ch]
[PATCH v7 06/10] Prepare linux_find_memory_regions_full & co. for move
[PATCH v7 07/10] Move linux_find_memory_regions_full & co.
There particularly the [PATCH v7 06/10] contains non-mechanical (a bit)
changes.
Thanks,
Jan
On Wed, 08 Jul 2015 17:39:14 +0200, Doug Evans wrote:
> On Sat, Jun 27, 2015 at 4:05 PM, Jan Kratochvil
> <jan.kratochvil@redhat.com> wrote:
> >> > ... This is actual
> >> > + BUILD_ID which comes either from the remote target via qXfer
> >> > + packet or via reading target memory. Therefore, it may differ
> >> > + from the build-id of the associated bfd. In a normal
> >> > + scenario, this so would soon lose its abfd due to failed
> >> > + validation.
> >>
> >> I can't read this last sentence.
> >> What are you trying to say here?
> >
> > It was written by Aleksandar Ristovski and I find it OK myself.
> > So as an explanation the process is:
> >
> > 1. GDB reads/receives so->build_id from GDB server.
> > 2. GDB opens local BFD so->abfd.
> > 3. GDB compares so->build_id with so->abfd->build_id (by ops->validate)
> > 4. If they differ so->abfd is freed/cleared (in solib_map_sections).
> >
> > Therefore could you suggest a different comment?
>
> I'd be ok with just deleting the last two sentences:
>
> This is actual
> BUILD_ID which comes either from the remote target via qXfer
> packet or via reading target memory.
>
> But if you want more I'm ok with:
>
> This is actual
> BUILD_ID which comes either from the remote target via qXfer
> packet or via reading target memory. Note that if there's a
> mismatch with the associated bfd then so->abfd will be cleared.
Used the latter one.
Thanks,
Jan
@@ -159,6 +159,12 @@ set debug linux-namespaces
show debug linux-namespaces
Control display of debugging info regarding Linux namespaces.
+set solib-build-id-force (on|off)
+show solib-build-id-force
+ Inferior shared library and symbol file may contain unique build-id.
+ If both build-ids are present but they do not match then this setting
+ enables (on) or disables (off) loading of such symbol file.
+
* The command 'thread apply all' can now support new option '-ascending'
to call its specified command for all threads in ascending order.
@@ -233,6 +239,12 @@ fork-events and vfork-events features in qSupported
* GDB now supports access to vector registers on S/390 GNU/Linux
targets.
+* New features in the GDB remote stub, GDBserver
+
+ ** library-list-svr4 contains also optional attribute 'build-id' for
+ each library. GDB does not load library with build-id that
+ does not match such attribute.
+
* Removed command line options
-xdb HP-UX XDB compatibility mode.
@@ -17912,6 +17912,44 @@ libraries that were loaded by explicit user requests are not
discarded.
@end table
+@table @code
+@kindex set solib-build-id-force
+@cindex override @value{GDBN} build-id check
+@item set solib-build-id-force @var{mode}
+Setting to override @value{GDBN} build-id check.
+
+Inferior shared libraries and symbol files may contain unique build-id.
+By default @value{GDBN} will ignore symbol files with non-matching build-id
+while printing:
+
+@smallexample
+ warning: Shared object "libfoo.so.1" could not be validated (remote
+ build ID 2bc1745e does not match local build ID a08f8767) and will be
+ ignored; or use 'set solib-build-id-force'.
+@end smallexample
+
+Turning on this setting would load such symbol file while still printing:
+
+@smallexample
+ warning: Shared object "libfoo.so.1" could not be validated (remote
+ build ID 2bc1745e does not match local build ID a08f8767) but it is
+ being loaded due to 'set solib-build-id-force'.
+@end smallexample
+
+If remote build-id is present but it does not match local build-id (or local
+build-id is not present) then this setting enables (@var{mode} is @code{on}) or
+disables (@var{mode} is @code{off}) loading of such symbol file. On systems
+where build-id is not present in the remote system this setting has no effect.
+The default value is @code{off}.
+
+Loading non-matching symbol file may confuse debugging including breakage
+of backtrace output.
+
+@kindex show solib-build-id-force
+@item show solib-build-id-force
+Display the current mode of build-id check override.
+@end table
+
Sometimes you may wish that @value{GDBN} stops and gives you control
when any of shared library events happen. The best way to do this is
to use @code{catch load} and @code{catch unload} (@pxref{Set
@@ -634,4 +634,5 @@ _initialize_darwin_solib (void)
darwin_so_ops.in_dynsym_resolve_code = darwin_in_dynsym_resolve_code;
darwin_so_ops.lookup_lib_global_symbol = darwin_lookup_lib_symbol;
darwin_so_ops.bfd_open = darwin_bfd_open;
+ darwin_so_ops.validate = default_solib_validate;
}
@@ -1080,6 +1080,7 @@ _initialize_dsbt_solib (void)
dsbt_so_ops.open_symbol_file_object = open_symbol_file_object;
dsbt_so_ops.in_dynsym_resolve_code = dsbt_in_dynsym_resolve_code;
dsbt_so_ops.bfd_open = solib_bfd_open;
+ dsbt_so_ops.validate = default_solib_validate;
/* Debug this file's internals. */
add_setshow_zuinteger_cmd ("solib-dsbt", class_maintenance,
@@ -1183,6 +1183,7 @@ _initialize_frv_solib (void)
frv_so_ops.open_symbol_file_object = open_symbol_file_object;
frv_so_ops.in_dynsym_resolve_code = frv_in_dynsym_resolve_code;
frv_so_ops.bfd_open = solib_bfd_open;
+ frv_so_ops.validate = default_solib_validate;
/* Debug this file's internals. */
add_setshow_zuinteger_cmd ("solib-frv", class_maintenance,
@@ -519,6 +519,7 @@ set_spu_solib_ops (struct gdbarch *gdbarch)
spu_so_ops.current_sos = spu_current_sos;
spu_so_ops.bfd_open = spu_bfd_open;
spu_so_ops.lookup_lib_global_symbol = spu_lookup_lib_symbol;
+ spu_so_ops.validate = default_solib_validate;
}
set_solib_ops (gdbarch, &spu_so_ops);
@@ -45,6 +45,9 @@
#include "auxv.h"
#include "gdb_bfd.h"
#include "probe.h"
+#include "rsp-low.h"
+
+#define NOTE_GNU_BUILD_ID_NAME ".note.gnu.build-id"
static struct link_map_offsets *svr4_fetch_link_map_offsets (void);
static int svr4_have_link_map_offsets (void);
@@ -970,6 +973,63 @@ svr4_keep_data_in_core (CORE_ADDR vaddr, unsigned long size)
return (name_lm >= vaddr && name_lm < vaddr + size);
}
+/* Validate SO by comparing build-id from the associated bfd and
+ corresponding build-id from target memory. */
+
+static char *
+svr4_validate (const struct so_list *const so)
+{
+ const bfd_byte *local_id;
+ size_t local_idsz;
+
+ gdb_assert (so != NULL);
+
+ /* Target doesn't support reporting the build ID or the remote shared library
+ does not have build ID. */
+ if (so->build_id == NULL)
+ return NULL;
+
+ /* Build ID may be present in the local file, just GDB is unable to retrieve
+ it. As it has been reported by gdbserver it is not FSF gdbserver. */
+ if (so->abfd == NULL
+ || !bfd_check_format (so->abfd, bfd_object))
+ return NULL;
+
+ /* GDB has verified the local file really does not contain the build ID. */
+ if (so->abfd->build_id == NULL)
+ {
+ char *remote_hex;
+
+ remote_hex = alloca (so->build_idsz * 2 + 1);
+ bin2hex (so->build_id, remote_hex, so->build_idsz);
+
+ return xstrprintf (_("remote build ID is %s "
+ "but local file does not have build ID"),
+ remote_hex);
+ }
+
+ local_id = so->abfd->build_id->data;
+ local_idsz = so->abfd->build_id->size;
+
+ if (so->build_idsz != local_idsz
+ || memcmp (so->build_id, local_id, so->build_idsz) != 0)
+ {
+ char *remote_hex, *local_hex;
+
+ remote_hex = alloca (so->build_idsz * 2 + 1);
+ bin2hex (so->build_id, remote_hex, so->build_idsz);
+ local_hex = alloca (local_idsz * 2 + 1);
+ bin2hex (local_id, local_hex, local_idsz);
+
+ return xstrprintf (_("remote build ID %s "
+ "does not match local build ID %s"),
+ remote_hex, local_hex);
+ }
+
+ /* Both build IDs are present and they match. */
+ return NULL;
+}
+
/* Implement the "open_symbol_file_object" target_so_ops method.
If no open symbol file, attempt to locate and open the main symbol
@@ -1108,6 +1168,12 @@ svr4_copy_library_list (struct so_list *src)
newobj->lm_info = xmalloc (sizeof (struct lm_info));
memcpy (newobj->lm_info, src->lm_info, sizeof (struct lm_info));
+ if (newobj->build_id != NULL)
+ {
+ newobj->build_id = xmalloc (src->build_idsz);
+ memcpy (newobj->build_id, src->build_id, src->build_idsz);
+ }
+
newobj->next = NULL;
*link = newobj;
link = &newobj->next;
@@ -1135,6 +1201,9 @@ library_list_start_library (struct gdb_xml_parser *parser,
ULONGEST *lmp = xml_find_attribute (attributes, "lm")->value;
ULONGEST *l_addrp = xml_find_attribute (attributes, "l_addr")->value;
ULONGEST *l_ldp = xml_find_attribute (attributes, "l_ld")->value;
+ const struct gdb_xml_value *const att_build_id
+ = xml_find_attribute (attributes, "build-id");
+ const char *const hex_build_id = att_build_id ? att_build_id->value : NULL;
struct so_list *new_elem;
new_elem = XCNEW (struct so_list);
@@ -1146,6 +1215,25 @@ library_list_start_library (struct gdb_xml_parser *parser,
strncpy (new_elem->so_name, name, sizeof (new_elem->so_name) - 1);
new_elem->so_name[sizeof (new_elem->so_name) - 1] = 0;
strcpy (new_elem->so_original_name, new_elem->so_name);
+ if (hex_build_id != NULL)
+ {
+ const size_t hex_build_id_len = strlen (hex_build_id);
+
+ if (hex_build_id_len > 0 && (hex_build_id_len & 1U) == 0)
+ {
+ const size_t build_idsz = hex_build_id_len / 2;
+
+ new_elem->build_id = xmalloc (build_idsz);
+ new_elem->build_idsz = hex2bin (hex_build_id, new_elem->build_id,
+ build_idsz);
+ if (new_elem->build_idsz != build_idsz)
+ {
+ xfree (new_elem->build_id);
+ new_elem->build_id = NULL;
+ new_elem->build_idsz = 0;
+ }
+ }
+ }
*list->tailp = new_elem;
list->tailp = &new_elem->next;
@@ -1180,6 +1268,7 @@ static const struct gdb_xml_attribute svr4_library_attributes[] =
{ "lm", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
{ "l_addr", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
{ "l_ld", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
+ { "build-id", GDB_XML_AF_OPTIONAL, NULL, NULL },
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
@@ -3258,4 +3347,5 @@ _initialize_svr4_solib (void)
svr4_so_ops.keep_data_in_core = svr4_keep_data_in_core;
svr4_so_ops.update_breakpoints = svr4_update_solib_event_breakpoints;
svr4_so_ops.handle_event = svr4_handle_solib_event;
+ svr4_so_ops.validate = svr4_validate;
}
@@ -25,6 +25,7 @@
#include "target.h"
#include "vec.h"
#include "solib-target.h"
+#include "solib.h"
/* Private data for each loaded library. */
struct lm_info
@@ -506,6 +507,7 @@ _initialize_solib_target (void)
solib_target_so_ops.in_dynsym_resolve_code
= solib_target_in_dynsym_resolve_code;
solib_target_so_ops.bfd_open = solib_bfd_open;
+ solib_target_so_ops.validate = default_solib_validate;
/* Set current_target_so_ops to solib_target_so_ops if not already
set. */
@@ -523,6 +523,20 @@ solib_bfd_open (char *pathname)
return abfd;
}
+/* Boolean for command 'set solib-build-id-force'. */
+static int solib_build_id_force = 0;
+
+/* Implement 'show solib-build-id-force'. */
+
+static void
+show_solib_build_id_force (struct ui_file *file, int from_tty,
+ struct cmd_list_element *c, const char *value)
+{
+ fprintf_filtered (file, _("Loading of shared libraries "
+ "with non-matching build-id is %s.\n"),
+ value);
+}
+
/* Given a pointer to one of the shared objects in our list of mapped
objects, use the recorded name to open a bfd descriptor for the
object, build a section table, relocate all the section addresses
@@ -539,7 +553,7 @@ static int
solib_map_sections (struct so_list *so)
{
const struct target_so_ops *ops = solib_ops (target_gdbarch ());
- char *filename;
+ char *filename, *validate_error;
struct target_section *p;
struct cleanup *old_chain;
bfd *abfd;
@@ -555,6 +569,27 @@ solib_map_sections (struct so_list *so)
/* Leave bfd open, core_xfer_memory and "info files" need it. */
so->abfd = abfd;
+ gdb_assert (ops->validate != NULL);
+
+ validate_error = ops->validate (so);
+ if (validate_error != NULL)
+ {
+ if (!solib_build_id_force)
+ {
+ warning (_("Shared object \"%s\" could not be validated (%s) and "
+ "will be ignored; or use 'set solib-build-id-force'."),
+ so->so_name, validate_error);
+ xfree (validate_error);
+ gdb_bfd_unref (so->abfd);
+ so->abfd = NULL;
+ return 0;
+ }
+ warning (_("Shared object \"%s\" could not be validated (%s) "
+ "but it is being loaded due to 'set solib-build-id-force'."),
+ so->so_name, validate_error);
+ xfree (validate_error);
+ }
+
/* Copy the full path name into so_name, allowing symbol_file_add
to find it later. This also affects the =library-loaded GDB/MI
event, and in particular the part of that notification providing
@@ -631,6 +666,9 @@ clear_so (struct so_list *so)
of the symbol file. */
strcpy (so->so_name, so->so_original_name);
+ xfree (so->build_id);
+ so->build_id = NULL;
+
/* Do the same for target-specific data. */
if (ops->clear_so != NULL)
ops->clear_so (so);
@@ -1662,6 +1700,14 @@ remove_user_added_objfile (struct objfile *objfile)
}
}
+/* Default implementation does not perform any validation. */
+
+char *
+default_solib_validate (const struct so_list *const so)
+{
+ return NULL; /* No validation. */
+}
+
extern initialize_file_ftype _initialize_solib; /* -Wmissing-prototypes */
void
@@ -1719,4 +1765,18 @@ PATH and LD_LIBRARY_PATH."),
reload_shared_libraries,
show_solib_search_path,
&setlist, &showlist);
+
+ add_setshow_boolean_cmd ("solib-build-id-force", class_support,
+ &solib_build_id_force, _("\
+Set loading of shared libraries with non-matching build-id."), _("\
+Show loading of shared libraries with non-matching build-id."), _("\
+Inferior shared library and symbol file may contain unique build-id.\n\
+If both build-ids are present but they do not match then this setting\n\
+enables (on) or disables (off) loading of such symbol file.\n\
+Loading non-matching symbol file may confuse debugging including breakage\n\
+of backtrace output."),
+ NULL,
+ show_solib_build_id_force,
+ &setlist, &showlist);
+
}
@@ -98,4 +98,8 @@ extern void update_solib_breakpoints (void);
extern void handle_solib_event (void);
+/* Default validation always returns 1. */
+
+extern char *default_solib_validate (const struct so_list *so);
+
#endif /* SOLIB_H */
@@ -75,6 +75,22 @@ struct so_list
There may not be just one (e.g. if two segments are relocated
differently); but this is only used for "info sharedlibrary". */
CORE_ADDR addr_low, addr_high;
+
+ /* Build id in raw format, contains verbatim contents of
+ .note.gnu.build-id including note header. This is actual
+ BUILD_ID which comes either from the remote target via qXfer
+ packet or via reading target memory. Therefore, it may differ
+ from the build-id of the associated bfd. In a normal
+ scenario, this so would soon lose its abfd due to failed
+ validation.
+ Reading target memory should be done by following execution view
+ of the binary (following program headers in the case of ELF).
+ Computing address from the linking view (following ELF section
+ headers) may give incorrect build-id memory address despite the
+ symbols still match.
+ Such an example is a prelinked vs. unprelinked i386 ELF file. */
+ size_t build_idsz;
+ gdb_byte *build_id;
};
struct target_so_ops
@@ -168,6 +184,11 @@ struct target_so_ops
NULL, in which case no specific preprocessing is necessary
for this target. */
void (*handle_event) (void);
+
+ /* Return NULL if SO does match target SO it is supposed to
+ represent. Otherwise return string describing why it does not match.
+ Caller has to free the string. */
+ char *(*validate) (const struct so_list *so);
};
/* Free the memory associated with a (so_list *). */