Giving linker script symbols defined outside of output sections a
section-relative value early, leads to them being used in expressions
as if they were defined inside an output section. This can mean loss
of the section VMA, and wrong results.
ld/
PR ld/18963
* ldexp.h (struct ldexp_control): Add rel_from_abs.
(ldexp_finalize_syms): Declare.
* ldexp.c (new_rel_from_abs): Keep absolute for expressions
outside of output section statements. Set rel_from_abs.
(make_abs, exp_fold_tree, exp_fold_tree_no_dot): Clear rel_from_abs.
(struct definedness_hash_entry): Add final_sec, and comment.
(update_definedness): Set final_sec.
(set_sym_sections, ldexp_finalize_syms): New functions.
* ldlang.c (lang_process): Call ldexp_finalize_syms.
ld/testsuite
PR ld/18963
* ld-scripts/pr18963.d,
* ld-scripts/pr18963.t: New test.
* ld-scripts/expr.exp: Run it.
* ld-elf/provide-hidden-2.ld: Explicitly make "dot" absolute.
* ld-mips-elf/gp-hidden.sd: Don't care about _gp section.
* ld-mips-elf/no-shared-1-n32.d: Don't care about symbol shown at
start of .data section.
* ld-mips-elf/no-shared-1-n64.d: Likewise.
* ld-mips-elf/no-shared-1-o32.d: Likewise.
The linker tries to put the end of the last section in the relro
segment exactly on a page boundary, because the relro segment itself
must end on a page boundary. If for any reason this can't be done,
padding is inserted. Since the end of the relro segment is typically
between .got and .got.plt, padding effectively increases the size of
the GOT. This isn't nice for targets and code models with limited GOT
addressing.
The problem with the current code is that it doesn't cope very well
with aligned sections in the relro segment. When making .got aligned
to a 256 byte boundary for PowerPC64, I found that often the initial
alignment attempt failed and the fallback attempt to be less than
adequate. This is a particular problem for PowerPC64 since the
distance between .got and .plt affects the size of plt call stubs,
leading to "stubs don't match calculated size" errors.
So this rewrite takes a direct approach to calculating a new relro
base. Starting from the last section in the segment, we calculate
where it must start to position its end on the boundary, or as near as
possible considering alignment requirements. The new start then
becomes the goal for the previous section to end, and so on for all
sections. This of course ignores the possibility that user scripts
will place . = ALIGN(xxx); in the relro segment, or provide section
address expressions. In those cases we might fail, but the old code
probably did too, and a fallback is provided.
ld/
* ldexp.h (struct ldexp_control): Delete dataseg.min_base. Add
data_seg.relro_offset.
* ldexp.c (fold_binary <DATA_SEGMENT_ALIGN>): Don't set min_base.
(fold_binary <DATA_SEGMENT_RELRO_END>): Do set relro_offset.
* ldlang.c (lang_size_sections): Rewrite code adjusting relro
segment base to line up last section on page boundary.
ld/testsuite/
* ld-x86-64/pr18176.d: Update.
This moves support code for DEFINED to ldexp.c where it is used,
losing the lang_ prefix on identifiers. Two new functions are needed
to initialize and clean up to hash table, but other than that there
are no functional changes here.
* ldexp.c (struct definedness_hash_entry, definedness_table)
(definedness_newfunc, symbol_defined, update_definedness): Move
and rename from..
* ldlang.h (struct lang_definedness_hash_entry): ..here,..
* ldlang.c (lang_definedness_table, lang_definedness_newfunc)
(lang_symbol_defined, lang_update_definedness): ..and here.
* ldexp.c (ldexp_init, ldexp_finish): New functions, extracted from..
* ldlang.c (lang_init, lang_finish): ..here.
* ldexp.h (ldexp_init, ldexp_finish): Declare.
* ldlang.h (lang_symbol_defined, lang_update_definedness): Delete.
* ldmain.c (main): Call ldexp_init and ldexp_finish.
* ldexp.h (struct ldexp_control): Add "assign_name".
* ldexp.c (fold_name <NAME>): Compare and clear assign_name on match.
(exp_fold_tree_1): Remove existing code testing for self assignment.
Instead set and test expld.assign_name.
* ldlang.c (scan_for_self_assignment): Delete.
(print_assignment): Instead set and test expld.assign_name.
* ldlang.c (lang_process): Rerun lang_do_assignments before
starting garbage collection.
* ldexp.c (fold_name): Generate a reloc for defined symbols
found without an associated output section during the mark phase.
(exp_fold_tree_1): Continue processing an expression, even if we
are unable to fold it, if we are in the first two evaluation
phases.
* ldexp.h (enum lang_phase_type): Add descriptions of the phases.
* ld-gc/pr13683.c: New test source file.
* ld-gc/pr13683.d: New test control and output file.
* ld-gc/gc.exp: Run the pr13683 test.
* ld-cris/tls-gc-68: Update expected symbol table dump.
* ld-cris/tls-gc-69: Likewise.
* ld-cris/tls-gc-70: Likewise.
* ld-cris/tls-gc-71: Likewise.
* ld-cris/tls-gc-75: Likewise.
* ld-cris/tls-gc-76.d: Likewise.
* ld-cris/tls-gc-79.d: Likewise.
* ld.h (parsing_defsym): Delete.
* ldexp.c (exp_intop, exp_bigintop, exp_relop): Set type.filename.
(fold_binary, fold_name, exp_fold_tree_1, exp_get_vma, exp_get_fill,
exp_get_abs_int): Add tree arg for %S in error messages. Don't
fudge lineno.
(exp_binop, exp_unop, exp_nameop, exp_assop, exp_assert): Copy
type.filename from sub-tree.
(exp_trinop): Likewise, and use "cond" rather than "lhs".
* ldexp.h (node_type): Add filename field to struct.
* ldfile.c (ldfile_input_filename): Delete. Remove all refs.
* ldfile.h (ldfile_input_filename): Delete.
* ldgram.y (phdr_type, phdr_qualifiers, yyerror): Add NULL arg for
%S in error messages.
* ldemul.c (syslib_default, hll_default): Likewise.
* ldlang.c (lang_memory_region_lookup, lang_memory_region_alias,
lang_get_regions, lang_new_phdr): Likewise.
(lang_size_sections_1): Pass addr_tree for %S.
* ldlex.h (lex_redirect): Update prototype.
(ldlex_filename): Declare.
* ldlex.l (<EOF>): Don't set ldfile_input_filename.
(lex_redirect): Add fake_filename and count params. Push
fake_filename to file_name_stack and init lineno from count.
(ldlex_filename): New function.
(lex_warn_invalid): Use above.
* ldmain.c (main): Update lex_redirect call.
* ldmisc.c (vfinfo <%S>): Take file name and line number from
etree_type arg, or use current if arg is NULL.
* lexsup.c (parsing_defsym): Delete.
(parse_args <OPTION_DEFSYM>): Update lex_redirect call.
* ldexp.h (enum phase_enum): Comment. Add exp_dataseg_done.
* ldexp.c (fold_unary <DATA_SEGMENT_END>): Rearrange code. Test
for exp_dataseg_done rather than expld.phase == lang_final_phase_enum
to detect when we've finished sizing sections.
(fold_binary <DATA_SEGMENT_ALIGN>): Likewise.
(fold_binary <DATA_SEGMENT_RELRO_END>): Likewise. Also test
that we are not inside an output section statement.
* ldlang.c (lang_size_sections): Set exp_dataseg_done on exit if
not exp_dataseg_relro_adjust or exp_dataseg_adjust. Don't set
lang_final_phase_enum here.
(lang_process): Set lang_final_phase_enum here.
2007-04-02 H.J. Lu <hongjiu.lu@intel.com>
PR ld/4090
* ldexp.h (node_type): Add lineno.
* ldexp.c: Include "ldlex.h".
(exp_intop): Set the lineno field from lineno.
(exp_bigintop): Likewise.
(exp_relop): Likewise.
(exp_nameop): Likewise.
(exp_binop): Set the lineno field from lineno of lhs.
(exp_trinop): Likewise.
(exp_unop): Set the lineno field from lineno of child.
(exp_assop): Set the lineno field from lineno of src.
(exp_provide): Likewise.
(exp_assert): Set the lineno field from lineno of exp.
(exp_get_abs_int): Set lineno from lineno of nonconstant
expression when report problem.
ld/testsuite/
2007-04-02 H.J. Lu <hongjiu.lu@intel.com>
PR ld/4090
* ld-elf/expr1.d: New file.
* ld-elf/expr1.s: Likewise.
* ld-elf/expr1.t: Likewise.
* ldexp.h: ..here. Add lang_mark_phase_enum.
(node_type): Remove etree_undef and etree_unspec.
(exp_data_seg): Delete.
(struct ldexp_control, expld): New.
(invalid, exp_mark_used_section): Delete.
(exp_fold_tree, exp_get_vma, exp_get_value_int, exp_get_fill,
exp_get_abs_int): Update prototypes.
* ldexp.c (assigning_to_dot): Delete.
(expld): Define.
(make_abs): Operate directly on expld.result. Update all callers.
(new_abs): Likewise. Return void.
(new_rel_from_abs): Rename from new_rel_from_section.
(new_rel, new_rel_from_abs): Operate on expld.result and return void.
Update all callers.
(fold_unary): Operate on expld.result and return void. Remove
"current_section", "allocation_done", "dot", "dotp" and "mark_used"
params. Update all callers.
(fold_binary, fold_trinary, fold_name, exp_fold_tree_1): Likewise.
(fold_unary <ALIGN_K>): Ensure alignment is absolute.
(fold_unary <ABSOLUTE>): Use make_abs.
(fold_unary <DATA_SEGMENT_END>): Evaluate mark_phase as for
allocating_phase.
(fold_binary <DATA_SEGMENT_ALIGN, DATA_SEGMENT_RELRO_END, >): Ditto.
(fold_binary <'%','/'>): Don't error if marking.
(fold_name <SIZEOF_HEADERS>): Don't call bfd_sizeof_headers when
marking.
(fold_name <NAME>): Remove FIXME; -R is handled correctly. Don't
error when marking.
(fold_name <ADDR, LOADADDR, SIZEOF>): Don't set SEC_KEEP.
(exp_fold_tree_1): Don't error when marking.
(exp_fold_tree_1 <etree_rel>): Evaluate in all phases except first.
(exp_fold_tree_1 <etree_assign to dot>): Don't check for NULL
current section, instead check for NULL dotp.
(exp_fold_tree_1 <etree_provide>): Don't evaluate the assignment
source unless the symbol is referenced and undefined.
(exp_fold_tree): Remove "allocation_done" and "dot" params. Save
params to expld.
(exp_fold_tree_no_dot): Remove "current_section", "allocation_done
and "mark_used" params. Save params to expld. Update all callers.
(exp_assop): Do without temp var.
(exp_print_tree <etree_undef>): Delete code.
(exp_get_vma): Remove "allocation_done" param. Correct error return.
(exp_get_fill, exp_get_abs_int): Likewise.
(exp_get_value_int): Remove "allocation_done" param.
(exp_mark_used_section): Delete.
* ldgram.y (fill_exp): Update exp_get_fill call.
(origin_spec, length_spec): Update exp_get_vma call.
* ldlang.c (lang_init): Don't bother clearing lang_statement_iteration.
(lang_mark_used_section_1, lang_mark_used_section): Delete.
(strip_excluded_output_sections): Call one_lang_size_sections_pass in
marking mode. Merge old lang_mark_used_section code. Correct handling
of output sections with excluded input sections and data statements.
Don't drop non-zero sized sections. Don't zap os->bfd_section.
Do set SEC_EXCLUDE when appropriate.
(print_output_section_statement): Update for changed ldexp.c
interface.
(print_assignment, lang_size_sections_1): Likewise.
(lang_do_assignments_1, lang_enter_output_section_statement): Likewise.
(lang_new_phdr, lang_record_phdrs): Likewise.
(lang_size_sections): Likewise.
(insert_pad): Use following statement if it is a pad, rather than
creating a new one.
(lang_size_sections_1 <lang_output_section_statement_enum>): Do
process ignored output section to set vma and lma, but don't
update dot for these sections. Don't error if marking.
(lang_size_sections_1 <lang_assignment_statement_enum>): Don't
update dot for ignored sections.
(lang_size_sections_1 <lang_data_statement_enum>): Don't mark absolute
section with SEC_ALLOC.
(one_lang_size_sections_pass): New function.
(lang_size_sections): Remove first five params. Set expld.phase on
entry and exit. Use one_lang_size_sections_pass.
(lang_do_assignments): Remove all params. Update all callers.
(lang_reset_memory_regions): Clear os->processed for all output
section statements.
* ldlang.h (lang_do_assignments): Update prototype.
(lang_size_sections): Likewise.
(one_lang_size_sections_pass): Declare.
* pe-dll.c (pe_dll_fill_sections, pe_exe_fill_sections): Update
lang_size_sections and lang_do_assignments calls.
* emultempl/elf32.em (layout_sections_again): Likewise.
* emultempl/ppc64elf.em (ppc_before_allocation): Use
one_lang_size_sections_pass.
* ldexp.c (fold_binary) <case DATA_SEGMENT_ALIGN>: Initialize them.
* ldlang.c (lang_size_sections): Use them to avoid wasting virtual
address space at DATA_SEGMENT_ALIGN. Fix computation of expected
PT_GNU_RELRO segment end.
* ldexp.h (segment_type): New type.
(segments): New variable.
* ldexp.c (segments): New variable.
(exp_print_token): Handle SEGMENT_START.
(fold_binary): Likewise.
* ldgram.y (SEGMENT_START): Declare it as a token.
(exp): Handle SEGMENT_START.
* ldlang.h (lang_address_statement_type): Add segment field.
(lang_section_start): Change prototype.
* ldlang.c (map_input_to_output_sections): Do not process section
assignments if a corresponding SEGMENT_START has already been
seen.
(lang_section_start): Add segment parameter.
* ldlex.l (SEGMENT_START): Add it.
* lexsup.c (seg_segment_start): New function.
(parse_args): Use it for -Tbss, -Tdata, and -Ttext.
* ld.texinfo (SEGMENT_START): Document it.
* emulparams/armsymbian.sh (EMBEDDED): Set it.
* scripttempl/armbpabi.sc: Use SEGMENT_START to control segment
base addresses. Do not map relocations.
* NEWS: Mention SEGMENT_START.
* ldexp.h (etree_value_type): Add "str" field.
(union etree_union): Add "str" to "value" struct.
(exp_bigintop): Declare.
(exp_get_fill): Declare.
* ldexp.c: Include "safe-ctype.h".
(exp_intop): Set value.str to NULL.
(exp_bigintop): New function.
(new_rel): Pass in "str", and set new.str from it.
(new_rel_from_section): Set new.str to NULL.
(fold_name): Adjust calls to new_rel.
(exp_fold_tree): Likewise.
(exp_get_fill): New function.
* ldgram.y (struct big_int bigint, fill_type *fill): New.
(INT): Returns a "bigint". Adjust all code handling INTs.
(fill_opt): Returns a "fill".
(fill_exp): Split out of fill_opt, use for FILL.
* ldlang.h (struct _fill_type): New.
(fill_type): Move typedef to ldexp.h.
(lang_output_section_statement_type): "fill" is now a pointer.
(lang_fill_statement_type): Likewise.
(lang_padding_statement_type): Likewise.
(lang_add_fill): Now takes a "fill_type *" param.
(lang_leave_output_section_statement): Likewise.
(lang_do_assignments): Likewise.
(lang_size_sections): Likewise.
(lang_leave_overlay_section): Likewise.
(lang_leave_overlay): Likewise.
* ldlang.c: Include ldgram.h after ldexp.h.
(lang_output_section_statement_lookup): Adjust for fill_type change.
(print_fill_statement): Likewise.
(print_padding_statement): Likewise.
(insert_pad): Now takes a "fill_type *" arg.
(size_input_section): Likewise.
(lang_size_sections_1): Likewise.
(lang_size_sections): Likewise.
(lang_do_assignments): Likewise.
(lang_add_fill): Likewise.
(lang_leave_output_section_statement): Likewise.
(lang_leave_overlay_section): Likewise.
(lang_leave_overlay): Likewise.
Adjust all callers of the above function.
* ldlex.l: Include ldgram.h after ldexp.h. Allow hex numbers
starting with "0X" as well as "0x". Return bigint.str for hex
numbers starting with "0x" or "0X", zero bigint.str otherwise.
Always use base 16 for numbers starting with "$".
* ldmain.c: Include ldgram.h after ldexp.h.
* ldwrite.c (build_link_order): Use bfd_data_link_order in place
of bfd_fill_link_order.
* pe-dll.c: Adjust lang_do_assignments calls.
* emultempl/elf32.em: Likewise.
* emultempl/hppaelf.em: Likewise.
* emultempl/ppc64elf.em: Likewise.
* emultempl/beos.em: Include ldgram.h after ldexp.h, adjust
lang_add_assignment call.
* emultempl/pe.em: Likewise.
* ldgram.y (DATA_SEGMENT_ALIGN, DATA_SEGMENT_END): New tokens.
(exp): Add DATA_SEGMENT_ALIGN (exp, exp) and DATA_SEGMENT_END (exp).
* ldexp.c (exp_data_seg): New variable.
(exp_print_token): Handle DATA_SEGMENT_ALIGN and DATA_SEGMENT_END.
(fold_binary): Handle DATA_SEGMENT_ALIGN.
(exp_fold_tree): Handle DATA_SEGMENT_END.
Pass allocation_done when recursing instead of hardcoding
lang_allocating_phase_enum.
* ldexp.h (exp_data_seg): New.
* ldlang.c (lang_size_sections_1): Renamed from lang_size_sections.
(lang_size_sections): New.
* ld.texinfo (DATA_SEGMENT_ALIGN, DATA_SEGMENT_END): Document.
* scripttempl/elf.sc: Use DATA_SEGMENT_ALIGN and DATA_SEGMENT_END
if COMMONPAGESIZE is defined.
* emulparams/elf_i386.sh (COMMONPAGESIZE): Set to 4K.
* emulparams/elf32_sparc.sh (COMMONPAGESIZE): Set to 8K.
* emulparams/elf64_sparc.sh (COMMONPAGESIZE): Set to 8K.
* emulparams/elf64alpha.sh (COMMONPAGESIZE): Set to 8K.
* emulparams/elf64_ia64.sh (COMMONPAGESIZE): Set to 16K for shared
libraries only.
* ldexp.h (node_type): Add etree_provided.
* ldexp.c (exp_fold_tree): Handle etree_provided. Set the node
type to etree_provided if defined by PROVIDE. Allow updating
for etree_provided.
(exp_print_tree): Handle etree_provided.
* mpw-elfmips.c (gldelf32ebmip_find_exp_assignment): Handle
etree_provided.
Alan Modra
Maciej W. Rozycki
Nick Clifton
H.J. Lu
Jakub Jelinek
Mark Mitchell
Kazu Hirata
Richard Henderson