From 3883a0743bac6e6e2d05c70c0f8520453f904b17 Mon Sep 17 00:00:00 2001 From: Sriraman Tallam Date: Fri, 24 Aug 2012 18:35:35 +0000 Subject: [PATCH] Patch adds support to allow plugins to map selected subset of sections to unique segments. 2012-08-24 Sriraman Tallam * gold.cc (queue_middle_tasks): Call layout again when unique segments for sections is desired. * layout.cc (Layout::Layout): Initialize new members. (Layout::get_output_section_flags): New function. (Layout::choose_output_section): Call get_output_section_flags. (Layout::layout): Make output section for mapping to a unique segment. (Layout::insert_section_segment_map): New function. (Layout::attach_allocated_section_to_segment): Make unique segment for output sections marked so. (Layout::segment_precedes): Check for unique segments when sorting. * layout.h (Layout::Unique_segment_info): New struct. (Layout::Section_segment_map): New typedef. (Layout::insert_section_segment_map): New function. (Layout::get_output_section_flags): New function. (Layout::is_unique_segment_for_sections_specified): New function. (Layout::set_unique_segment_for_sections_specified): New function. (Layout::unique_segment_for_sections_specified_): New member. (Layout::section_segment_map_): New member. * object.cc (Sized_relobj_file::do_layout): Rename is_gc_pass_one to is_pass_one. Rename is_gc_pass_two to is_pass_two. Rename is_gc_or_icf to is_two_pass. Check for which pass based on whether symbols data is present. Make it two pass when unique segments for sections is desired. * output.cc (Output_section::Output_section): Initialize new members. * output.h (Output_section::is_unique_segment): New function. (Output_section::set_is_unique_segment): New function. (Output_section::is_unique_segment_): New member. (Output_section::extra_segment_flags): New function. (Output_section::set_extra_segment_flags): New function. (Output_section::extra_segment_flags_): New member. (Output_section::segment_alignment): New function. (Output_section::set_segment_alignment): New function. (Output_section::segment_alignment_): New member. (Output_segment::Output_segment): Initialize is_unique_segment_. (Output_segment::is_unique_segment): New function. (Output_segment::set_is_unique_segment): New function. (Output_segment::is_unique_segment_): New member. * plugin.cc (allow_unique_segment_for_sections): New function. (unique_segment_for_sections): New function. (Plugin::load): Add new functions to transfer vector. * Makefile.am (plugin_final_layout.readelf.stdout): Add readelf output. * Makefile.in: Regenerate. * testsuite/plugin_final_layout.sh: Check if unique segment functionality works. * testsuite/plugin_section_order.c (onload): Check if new interfaces are available. (allow_unique_segment_for_sections): New global. (unique_segment_for_sections): New global. (claim_file_hook): Call allow_unique_segment_for_sections. (all_symbols_read_hook): Call unique_segment_for_sections. 2012-08-24 Sriraman Tallam * plugin-api.h (ld_plugin_allow_unique_segment_for_sections): New interface. (ld_plugin_unique_segment_for_sections): New interface. (LDPT_ALLOW_UNIQUE_SEGMENT_FOR_SECTIONS): New enum val. (LDPT_UNIQUE_SEGMENT_FOR_SECTIONS): New enum val. (tv_allow_unique_segment_for_sections): New member. (tv_unique_segment_for_sections): New member. --- include/ChangeLog | 10 ++++++++++ include/plugin-api.h | 33 ++++++++++++++++++++++++++++++++- 2 files changed, 42 insertions(+), 1 deletion(-) diff --git a/include/ChangeLog b/include/ChangeLog index d6b329f96..ad7f0f154 100644 --- a/include/ChangeLog +++ b/include/ChangeLog @@ -1,3 +1,13 @@ +2012-08-24 Sriraman Tallam + + * plugin-api.h (ld_plugin_allow_unique_segment_for_sections): + New interface. + (ld_plugin_unique_segment_for_sections): New interface. + (LDPT_ALLOW_UNIQUE_SEGMENT_FOR_SECTIONS): New enum val. + (LDPT_UNIQUE_SEGMENT_FOR_SECTIONS): New enum val. + (tv_allow_unique_segment_for_sections): New member. + (tv_unique_segment_for_sections): New member. + 2012-08-24 Matthew Gretton-Dann * opcode/arm.h (ARM_CPU_IS_ANY): New define. diff --git a/include/plugin-api.h b/include/plugin-api.h index 3220142dd..af60419a9 100644 --- a/include/plugin-api.h +++ b/include/plugin-api.h @@ -318,6 +318,33 @@ typedef enum ld_plugin_status (*ld_plugin_allow_section_ordering) (void); +/* The linker's interface for specifying that a subset of sections is + to be mapped to a unique segment. If the plugin wants to call + unique_segment_for_sections, it must call this function from a + claim_file_handler or when it is first loaded. */ + +typedef +enum ld_plugin_status +(*ld_plugin_allow_unique_segment_for_sections) (void); + +/* The linker's interface for specifying that a specific set of sections + must be mapped to a unique segment. ELF segments do not have names + and the NAME is used as the name of the newly created output section + that is then placed in the unique PT_LOAD segment. FLAGS is used to + specify if any additional segment flags need to be set. For instance, + a specific segment flag can be set to identify this segment. Unsetting + segment flags that would be set by default is not possible. The + parameter SEGMENT_ALIGNMENT when non-zero will override the default. */ + +typedef +enum ld_plugin_status +(*ld_plugin_unique_segment_for_sections) ( + const char* segment_name, + uint64_t segment_flags, + uint64_t segment_alignment, + const struct ld_plugin_section * section_list, + unsigned int num_sections); + enum ld_plugin_level { LDPL_INFO, @@ -355,7 +382,9 @@ enum ld_plugin_tag LDPT_GET_INPUT_SECTION_CONTENTS, LDPT_UPDATE_SECTION_ORDER, LDPT_ALLOW_SECTION_ORDERING, - LDPT_GET_SYMBOLS_V2 + LDPT_GET_SYMBOLS_V2, + LDPT_ALLOW_UNIQUE_SEGMENT_FOR_SECTIONS, + LDPT_UNIQUE_SEGMENT_FOR_SECTIONS }; /* The plugin transfer vector. */ @@ -385,6 +414,8 @@ struct ld_plugin_tv ld_plugin_get_input_section_contents tv_get_input_section_contents; ld_plugin_update_section_order tv_update_section_order; ld_plugin_allow_section_ordering tv_allow_section_ordering; + ld_plugin_allow_unique_segment_for_sections tv_allow_unique_segment_for_sections; + ld_plugin_unique_segment_for_sections tv_unique_segment_for_sections; } tv_u; };