From a3ed37d8bcb97329ff3acebba63c754d153d3363 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Fri, 19 Jul 2013 23:07:08 +0000 Subject: [PATCH] gold/ * options.h (General_options): Add -Trodata-segment option. * parameters.cc (Parameters::check_rodata_segment): New function. (Parameters::set_target_once): Call it. * parameters.h (Parameters): Declare it (private member function). * layout.cc (load_seg_unusable_for_headers): New function, broken out of Layout::relaxation_loop_body. If TARGET->isolate_execinstr() then validate rodata segment rather than text segment. (relaxation_loop_body): Call that. (is_text_segment): New function. Don't admit a non-executable segment if TARGET->isolate_execinstr(). (set_segment_offsets): Call it. Honor -Trodata-segment option. --- gold/ChangeLog | 14 ++++++++++++++ gold/layout.cc | 44 ++++++++++++++++++++++++++++++++++++++------ gold/options.h | 2 ++ gold/parameters.cc | 16 ++++++++++++++-- gold/parameters.h | 5 ++++- 5 files changed, 72 insertions(+), 9 deletions(-) diff --git a/gold/ChangeLog b/gold/ChangeLog index 7f859b7f1ba..676b670fec8 100644 --- a/gold/ChangeLog +++ b/gold/ChangeLog @@ -1,3 +1,17 @@ +2013-07-19 Roland McGrath + + * options.h (General_options): Add -Trodata-segment option. + * parameters.cc (Parameters::check_rodata_segment): New function. + (Parameters::set_target_once): Call it. + * parameters.h (Parameters): Declare it (private member function). + * layout.cc (load_seg_unusable_for_headers): New function, broken + out of Layout::relaxation_loop_body. If TARGET->isolate_execinstr() + then validate rodata segment rather than text segment. + (relaxation_loop_body): Call that. + (is_text_segment): New function. Don't admit a non-executable + segment if TARGET->isolate_execinstr(). + (set_segment_offsets): Call it. Honor -Trodata-segment option. + 2013-07-15 Shawn Landden PR gold/15070 diff --git a/gold/layout.cc b/gold/layout.cc index 818773a9433..07dbc9bf592 100644 --- a/gold/layout.cc +++ b/gold/layout.cc @@ -2369,6 +2369,22 @@ Layout::prepare_for_relaxation() this->record_output_section_data_from_script_ = true; } +// If the user set the address of the text segment, that may not be +// compatible with putting the segment headers and file headers into +// that segment. For isolate_execinstr() targets, it's the rodata +// segment rather than text where we might put the headers. +static inline bool +load_seg_unusable_for_headers(const Target* target) +{ + const General_options& options = parameters->options(); + if (target->isolate_execinstr()) + return (options.user_set_Trodata_segment() + && options.Trodata_segment() % target->abi_pagesize() != 0); + else + return (options.user_set_Ttext() + && options.Ttext() % target->abi_pagesize() != 0); +} + // Relaxation loop body: If target has no relaxation, this runs only once // Otherwise, the target relaxation hook is called at the end of // each iteration. If the hook returns true, it means re-layout of @@ -2421,11 +2437,7 @@ Layout::relaxation_loop_body( != General_options::OBJECT_FORMAT_ELF) load_seg = NULL; - // If the user set the address of the text segment, that may not be - // compatible with putting the segment headers and file headers into - // that segment. - if (parameters->options().user_set_Ttext() - && parameters->options().Ttext() % target->abi_pagesize() != 0) + if (load_seg_unusable_for_headers(target)) { load_seg = NULL; phdr_seg = NULL; @@ -3319,6 +3331,20 @@ align_file_offset(off_t off, uint64_t addr, uint64_t abi_pagesize) return aligned_off; } +// On targets where the text segment contains only executable code, +// a non-executable segment is never the text segment. + +static inline bool +is_text_segment(const Target* target, const Output_segment* seg) +{ + elfcpp::Elf_Xword flags = seg->flags(); + if ((flags & elfcpp::PF_W) != 0) + return false; + if ((flags & elfcpp::PF_X) == 0) + return !target->isolate_execinstr(); + return true; +} + // Set the file offsets of all the segments, and all the sections they // contain. They have all been created. LOAD_SEG must be be laid out // first. Return the offset of the data to follow. @@ -3411,8 +3437,14 @@ Layout::set_segment_offsets(const Target* target, Output_segment* load_seg, } else if (parameters->options().user_set_Ttext() && (parameters->options().omagic() - || ((*p)->flags() & elfcpp::PF_W) == 0)) + || is_text_segment(target, *p))) + { + are_addresses_set = true; + } + else if (parameters->options().user_set_Trodata_segment() + && ((*p)->flags() & (elfcpp::PF_W | elfcpp::PF_X)) == 0) { + addr = parameters->options().Trodata_segment(); are_addresses_set = true; } else if (parameters->options().user_set_Tdata() diff --git a/gold/options.h b/gold/options.h index 052e382d737..a2f5a8864e3 100644 --- a/gold/options.h +++ b/gold/options.h @@ -1162,6 +1162,8 @@ class General_options DEFINE_uint64_alias(Ttext_segment, Ttext, options::ONE_DASH, '\0', N_("Set the address of the text segment"), N_("ADDRESS")); + DEFINE_uint64(Trodata_segment, options::ONE_DASH, '\0', -1U, + N_("Set the address of the rodata segment"), N_("ADDRESS")); DEFINE_bool(toc_optimize, options::TWO_DASHES, '\0', true, N_("(PowerPC64 only) Optimize TOC code sequences"), diff --git a/gold/parameters.cc b/gold/parameters.cc index d69b62c1430..27819908fe1 100644 --- a/gold/parameters.cc +++ b/gold/parameters.cc @@ -1,6 +1,6 @@ // parameters.cc -- general parameters for a link using gold -// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012 +// Copyright 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 // Free Software Foundation, Inc. // Written by Ian Lance Taylor . @@ -127,7 +127,10 @@ Parameters::set_target_once(Target* target) gold_assert(this->target_ == NULL); this->target_ = target; if (this->options_valid()) - this->check_target_endianness(); + { + this->check_target_endianness(); + this->check_rodata_segment(); + } } // Clear the target, for testing. @@ -219,6 +222,15 @@ Parameters::check_target_endianness() } } +void +Parameters::check_rodata_segment() +{ + if (this->options().user_set_Trodata_segment() + && !this->options().rosegment() + && !this->target().isolate_execinstr()) + gold_error(_("-Trodata-segment is meaningless without --rosegment")); +} + // Return the name of the entry symbol. const char* diff --git a/gold/parameters.h b/gold/parameters.h index 10de2ae7fa4..8d1ec2e1ebb 100644 --- a/gold/parameters.h +++ b/gold/parameters.h @@ -1,6 +1,6 @@ // parameters.h -- general parameters for a link using gold -*- C++ -*- -// Copyright 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. +// Copyright 2006, 2007, 2008, 2009, 2010, 2013 Free Software Foundation, Inc. // Written by Ian Lance Taylor . // This file is part of gold. @@ -183,6 +183,9 @@ class Parameters void check_target_endianness(); + void + check_rodata_segment(); + friend class Set_parameters_target_once; Errors* errors_; -- 2.30.2