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Re: Allow section offsets instead of segment offsets (qXfer:libraries:read+)
- From: Pedro Alves <pedro at codesourcery dot com>
- To: gdb-patches at sourceware dot org
- Date: Fri, 14 Mar 2008 22:31:44 +0000
- Subject: Re: Allow section offsets instead of segment offsets (qXfer:libraries:read+)
- References: <200802261906.49798.pedro@codesourcery.com> <20080314185106.GE31663@caradoc.them.org>
A Friday 14 March 2008 18:51:06, Daniel Jacobowitz wrote:
> On Tue, Feb 26, 2008 at 07:06:49PM +0000, Pedro Alves wrote:
> > + /* The target can either specify segment bases of section bases, not
> > + both. */
>
> of -> or
>
> Patch is OK; make sure the NEWS entry shows up in the right place,
> under "since 6.8".
Thanks! This is what I checked in.
--
Pedro Alves
2008-03-14 Pedro Alves <pedro@codesourcery.com>
* features/library-list.dtd: Allow "section" elements as children
of "library". Add "section" element and describe its attributes.
* solib-target.c (struct lm_info): Add section_bases member.
(library_list_start_segment): Error out if seen a section element.
(library_list_start_section): New.
(library_list_end_library): New.
(solib_target_free_library_list): Free section_bases.
(section_attributes): New.
(library_children): Make "segment" optional. Add "section" child.
(library_list_children): Register library_list_end_library.
(solib_target_relocate_section_addresses): Handle section bases.
* NEWS: Mention new qXfer:libraries:read section offsets support.
doc/
2008-03-14 Pedro Alves <pedro@codesourcery.com>
Sandra Loosemore <sandra@codesourcery.com>
* gdb.texinfo (Library List Format): Update to mention the
possibility to pass section addresses instead of segment
addresses.
---
gdb/NEWS | 3
gdb/doc/gdb.texinfo | 34 ++++++-
gdb/features/library-list.dtd | 5 -
gdb/solib-target.c | 197 +++++++++++++++++++++++++++++++++---------
4 files changed, 191 insertions(+), 48 deletions(-)
Index: src/gdb/features/library-list.dtd
===================================================================
--- src.orig/gdb/features/library-list.dtd 2008-03-14 22:09:39.000000000 +0000
+++ src/gdb/features/library-list.dtd 2008-03-14 22:10:42.000000000 +0000
@@ -8,8 +8,11 @@
<!ELEMENT library-list (library)*>
<!ATTLIST library-list version CDATA #FIXED "1.0">
-<!ELEMENT library (segment)*>
+<!ELEMENT library (segment*, section*)>
<!ATTLIST library name CDATA #REQUIRED>
<!ELEMENT segment EMPTY>
<!ATTLIST segment address CDATA #REQUIRED>
+
+<!ELEMENT section EMPTY>
+<!ATTLIST section address CDATA #REQUIRED>
Index: src/gdb/solib-target.c
===================================================================
--- src.orig/gdb/solib-target.c 2008-03-14 22:09:39.000000000 +0000
+++ src/gdb/solib-target.c 2008-03-14 22:10:42.000000000 +0000
@@ -37,12 +37,19 @@ struct lm_info
so_list; it is only here during XML parsing. */
char *name;
+ /* The target can either specify segment bases or section bases, not
+ both. */
+
/* The base addresses for each independently relocatable segment of
this shared library. */
VEC(CORE_ADDR) *segment_bases;
+ /* The base addresses for each independently allocatable,
+ relocatable section of this shared library. */
+ VEC(CORE_ADDR) *section_bases;
+
/* The cached offsets for each section of this shared library,
- determined from SEGMENT_BASES. */
+ determined from SEGMENT_BASES, or SECTION_BASES. */
struct section_offsets *offsets;
};
@@ -82,9 +89,30 @@ library_list_start_segment (struct gdb_x
ULONGEST *address_p = VEC_index (gdb_xml_value_s, attributes, 0)->value;
CORE_ADDR address = (CORE_ADDR) *address_p;
+ if (last->section_bases != NULL)
+ gdb_xml_error (parser,
+ _("Library list with both segments and sections"));
+
VEC_safe_push (CORE_ADDR, last->segment_bases, &address);
}
+static void
+library_list_start_section (struct gdb_xml_parser *parser,
+ const struct gdb_xml_element *element,
+ void *user_data, VEC(gdb_xml_value_s) *attributes)
+{
+ VEC(lm_info_p) **list = user_data;
+ struct lm_info *last = VEC_last (lm_info_p, *list);
+ ULONGEST *address_p = VEC_index (gdb_xml_value_s, attributes, 0)->value;
+ CORE_ADDR address = (CORE_ADDR) *address_p;
+
+ if (last->segment_bases != NULL)
+ gdb_xml_error (parser,
+ _("Library list with both segments and sections"));
+
+ VEC_safe_push (CORE_ADDR, last->section_bases, &address);
+}
+
/* Handle the start of a <library> element. */
static void
@@ -100,6 +128,20 @@ library_list_start_library (struct gdb_x
VEC_safe_push (lm_info_p, *list, item);
}
+static void
+library_list_end_library (struct gdb_xml_parser *parser,
+ const struct gdb_xml_element *element,
+ void *user_data, const char *body_text)
+{
+ VEC(lm_info_p) **list = user_data;
+ struct lm_info *lm_info = VEC_last (lm_info_p, *list);
+ if (lm_info->segment_bases == NULL
+ && lm_info->section_bases == NULL)
+ gdb_xml_error (parser,
+ _("No segment or section bases defined"));
+}
+
+
/* Handle the start of a <library-list> element. */
static void
@@ -128,6 +170,7 @@ solib_target_free_library_list (void *p)
{
xfree (info->name);
VEC_free (CORE_ADDR, info->segment_bases);
+ VEC_free (CORE_ADDR, info->section_bases);
xfree (info);
}
VEC_free (lm_info_p, *result);
@@ -142,9 +185,18 @@ const struct gdb_xml_attribute segment_a
{ NULL, GDB_XML_AF_NONE, NULL, NULL }
};
+const struct gdb_xml_attribute section_attributes[] = {
+ { "address", GDB_XML_AF_NONE, gdb_xml_parse_attr_ulongest, NULL },
+ { NULL, GDB_XML_AF_NONE, NULL, NULL }
+};
+
const struct gdb_xml_element library_children[] = {
- { "segment", segment_attributes, NULL, GDB_XML_EF_REPEATABLE,
+ { "segment", segment_attributes, NULL,
+ GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
library_list_start_segment, NULL },
+ { "section", section_attributes, NULL,
+ GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
+ library_list_start_section, NULL },
{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};
@@ -156,7 +208,7 @@ const struct gdb_xml_attribute library_a
const struct gdb_xml_element library_list_children[] = {
{ "library", library_attributes, library_children,
GDB_XML_EF_REPEATABLE | GDB_XML_EF_OPTIONAL,
- library_list_start_library, NULL },
+ library_list_start_library, library_list_end_library },
{ NULL, NULL, NULL, GDB_XML_EF_NONE, NULL, NULL }
};
@@ -285,55 +337,116 @@ solib_target_relocate_section_addresses
it any earlier, since we need to open the file first. */
if (so->lm_info->offsets == NULL)
{
- struct symfile_segment_data *data;
int num_sections = bfd_count_sections (so->abfd);
so->lm_info->offsets = xzalloc (SIZEOF_N_SECTION_OFFSETS (num_sections));
- data = get_symfile_segment_data (so->abfd);
- if (data == NULL)
- warning (_("Could not relocate shared library \"%s\": no segments"),
- so->so_name);
- else
+ if (so->lm_info->section_bases)
{
- ULONGEST orig_delta;
int i;
- int num_bases = VEC_length (CORE_ADDR, so->lm_info->segment_bases);
- CORE_ADDR *segment_bases = VEC_address (CORE_ADDR,
- so->lm_info->segment_bases);
-
- if (!symfile_map_offsets_to_segments (so->abfd, data,
- so->lm_info->offsets,
- num_bases, segment_bases))
- warning (_("Could not relocate shared library \"%s\": bad offsets"),
+ asection *sect;
+ int num_section_bases
+ = VEC_length (CORE_ADDR, so->lm_info->section_bases);
+ int num_alloc_sections = 0;
+
+ for (i = 0, sect = so->abfd->sections;
+ sect != NULL;
+ i++, sect = sect->next)
+ if ((bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
+ num_alloc_sections++;
+
+ if (num_alloc_sections != num_section_bases)
+ warning (_("\
+Could not relocate shared library \"%s\": wrong number of ALLOC sections"),
so->so_name);
-
- /* Find the range of addresses to report for this library in
- "info sharedlibrary". Report any consecutive segments
- which were relocated as a single unit. */
- gdb_assert (num_bases > 0);
- orig_delta = segment_bases[0] - data->segment_bases[0];
-
- for (i = 1; i < data->num_segments; i++)
+ else
{
- /* If we have run out of offsets, assume all remaining segments
- have the same offset. */
- if (i >= num_bases)
- continue;
-
- /* If this segment does not have the same offset, do not include
- it in the library's range. */
- if (segment_bases[i] - data->segment_bases[i] != orig_delta)
- break;
+ int bases_index = 0;
+ int found_range = 0;
+ CORE_ADDR *section_bases;
+ section_bases = VEC_address (CORE_ADDR,
+ so->lm_info->section_bases);
+
+ so->addr_low = ~(CORE_ADDR) 0;
+ so->addr_high = 0;
+ for (i = 0, sect = so->abfd->sections;
+ sect != NULL;
+ i++, sect = sect->next)
+ {
+ if (!(bfd_get_section_flags (so->abfd, sect) & SEC_ALLOC))
+ continue;
+ if (bfd_section_size (so->abfd, sect) > 0)
+ {
+ CORE_ADDR low, high;
+ low = section_bases[i];
+ high = low + bfd_section_size (so->abfd, sect) - 1;
+
+ if (low < so->addr_low)
+ so->addr_low = low;
+ if (high > so->addr_high)
+ so->addr_high = high;
+ gdb_assert (so->addr_low <= so->addr_high);
+ found_range = 1;
+ }
+ so->lm_info->offsets->offsets[i] = section_bases[bases_index];
+ bases_index++;
+ }
+ if (!found_range)
+ so->addr_low = so->addr_high = 0;
+ gdb_assert (so->addr_low <= so->addr_high);
}
+ }
+ else if (so->lm_info->segment_bases)
+ {
+ struct symfile_segment_data *data;
+ data = get_symfile_segment_data (so->abfd);
+ if (data == NULL)
+ warning (_("\
+Could not relocate shared library \"%s\": no segments"), so->so_name);
+ else
+ {
+ ULONGEST orig_delta;
+ int i;
+ int num_bases;
+ CORE_ADDR *segment_bases;
+
+ num_bases = VEC_length (CORE_ADDR, so->lm_info->segment_bases);
+ segment_bases = VEC_address (CORE_ADDR,
+ so->lm_info->segment_bases);
+
+ if (!symfile_map_offsets_to_segments (so->abfd, data,
+ so->lm_info->offsets,
+ num_bases, segment_bases))
+ warning (_("\
+Could not relocate shared library \"%s\": bad offsets"), so->so_name);
+
+ /* Find the range of addresses to report for this library in
+ "info sharedlibrary". Report any consecutive segments
+ which were relocated as a single unit. */
+ gdb_assert (num_bases > 0);
+ orig_delta = segment_bases[0] - data->segment_bases[0];
+
+ for (i = 1; i < data->num_segments; i++)
+ {
+ /* If we have run out of offsets, assume all
+ remaining segments have the same offset. */
+ if (i >= num_bases)
+ continue;
+
+ /* If this segment does not have the same offset, do
+ not include it in the library's range. */
+ if (segment_bases[i] - data->segment_bases[i] != orig_delta)
+ break;
+ }
+
+ so->addr_low = segment_bases[0];
+ so->addr_high = (data->segment_bases[i - 1]
+ + data->segment_sizes[i - 1]
+ + orig_delta);
+ gdb_assert (so->addr_low <= so->addr_high);
- so->addr_low = segment_bases[0];
- so->addr_high = (data->segment_bases[i - 1]
- + data->segment_sizes[i - 1]
- + orig_delta);
- gdb_assert (so->addr_low <= so->addr_high);
-
- free_symfile_segment_data (data);
+ free_symfile_segment_data (data);
+ }
}
}
Index: src/gdb/doc/gdb.texinfo
===================================================================
--- src.orig/gdb/doc/gdb.texinfo 2008-03-14 22:09:39.000000000 +0000
+++ src/gdb/doc/gdb.texinfo 2008-03-14 22:10:42.000000000 +0000
@@ -26334,10 +26334,15 @@ are loaded.
The @samp{qXfer:libraries:read} packet returns an XML document which
lists loaded libraries and their offsets. Each library has an
-associated name and one or more segment base addresses, which report
-where the library was loaded in memory. The segment bases are start
-addresses, not relocation offsets; they do not depend on the library's
-link-time base addresses.
+associated name and one or more segment or section base addresses,
+which report where the library was loaded in memory.
+
+For the common case of libraries that are fully linked binaries, the
+library should have a list of segments. If the target supports
+dynamic linking of a relocatable object file, its library XML element
+should instead include a list of allocated sections. The segment or
+section bases are start addresses, not relocation offsets; they do not
+depend on the library's link-time base addresses.
@value{GDBN} must be linked with the Expat library to support XML
library lists. @xref{Expat}.
@@ -26353,18 +26358,37 @@ offset, looks like this:
</library-list>
@end smallexample
+Another simple memory map, with one loaded library with three
+allocated sections (.text, .data, .bss), looks like this:
+
+@smallexample
+<library-list>
+ <library name="sharedlib.o">
+ <section address="0x10000000"/>
+ <section address="0x20000000"/>
+ <section address="0x30000000"/>
+ </library>
+</library-list>
+@end smallexample
+
The format of a library list is described by this DTD:
@smallexample
<!-- library-list: Root element with versioning -->
<!ELEMENT library-list (library)*>
<!ATTLIST library-list version CDATA #FIXED "1.0">
-<!ELEMENT library (segment)*>
+<!ELEMENT library (segment*, section*)>
<!ATTLIST library name CDATA #REQUIRED>
<!ELEMENT segment EMPTY>
<!ATTLIST segment address CDATA #REQUIRED>
+<!ELEMENT section EMPTY>
+<!ATTLIST section address CDATA #REQUIRED>
@end smallexample
+In addition, segments and section descriptors cannot be mixed within a
+single library element, and you must supply at least one segment or
+section for each library.
+
@node Memory Map Format
@section Memory Map Format
@cindex memory map format
Index: src/gdb/NEWS
===================================================================
--- src.orig/gdb/NEWS 2008-03-14 22:09:39.000000000 +0000
+++ src/gdb/NEWS 2008-03-14 22:18:27.000000000 +0000
@@ -6,6 +6,9 @@
* Watchpoints can now be set on unreadable memory locations, e.g. addresses
which will be allocated using malloc later in program execution.
+* The qXfer:libraries:read remote procotol packet now allows passing a
+ list of section offsets.
+
* New features in the GDB remote stub, gdbserver
- The "--wrapper" command-line argument tells gdbserver to use a