This patch processes linker script assignment statements before ld
opens DT_NEEDED libraries, in order to define symbols like __bss_start
that might also be defined by a library, falsely triggering an error
about "DSO missing from command line".
The initial value won't be correct when assigning a symbol from dot,
and I make no attempt to handle all expressions. For example, an
assignment like "_start_foo = ADDR (.foo)" isn't valid until sections
are laid out, so won't define _start_foo early. What's here should be
enough for most common scripts, and hopefully won't perturb fragile
scripts.
bfd/
PR 22471
* elflink.c (_bfd_elf_merge_symbol): Allow weak symbols to override
early passes over linker script symbols.
* linker.c (_bfd_generic_link_add_one_symbol): Allow symbols to
override early passes over linker script symbols. Clear ldscript_def
on symbol definitions.
ld/
PR 22471
* ldexp.c (struct definedness_hash_entry): Delete "by_script". Make
"iteration" an 8-bit field, and update mask in all uses.
(definedness_newfunc): Don't init "by_script".
(update_definedness): Test ldscript_def rather than by_script.
(is_sym_value): Likewise.
(fold_name <DEFINED>): Return a result for first phase. Test
ldscript_def.
(fold_name <NAME>): Return a result for first phase.
* ldlang.c (open_input_bfds): Process all assignments, not just
defsym.
(lang_process): Increment lang_statement_iteration before
open_input_bfds.
* testsuite/ld-mips-elf/tlsdyn-o32-1.d: Adjust for larger .dynsym.
* testsuite/ld-mips-elf/tlsdyn-o32-1.got: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-2.d: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-2.got: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-3.d: Likewise.
* testsuite/ld-mips-elf/tlsdyn-o32-3.got: Likewise.
There is a call to update_definedness between code that evaluates an
assignment expression value and code that transfers symbol
attributes. When script assignment expressions contain DEFINED, that
can mean the wrong symbol type is copied. This patch tracks symbols
read during expression evaluation, rather than examining the
expression and re-evaluating conditionals. Not only does this
simplify the code, it also means ld can now copy symbol types in more
complex expressions.
An unfortunate side effect of copying symbol type for more complex
expressions affects mmix, which uses
PROVIDE (Main = DEFINED (Main) ? Main : (DEFINED (_start) ? _start : _start.));
in a default script. So now _start or _start. symbol type may be
copied, losing the function type specially set up for Main. This can
be avoided by making bfd_copy_link_hash_symbol_type do nothing for
mmix.
bfd/
* elf64-mmix.c (bfd_elf64_bfd_copy_link_hash_symbol_type): Define.
ld/
* ldexp.h (struct ldexp_control): Add "assign_src".
* ldexp.c (fold_trinary): Save and restore assign_src around
condition evaluation.
(fold_name <NAME>): Set expld.assign_src.
(try_copy_symbol_type): Delete.
(exp_fold_tree_1): Set symbol type using expld.assign_src.
If linker plugin is enabled, set non_ir_ref_regular on symbols referenced
in regular objects so that linker plugin will get the correct symbol
resolution.
bfd/
PR ld/22502
* elflink.c (_bfd_elf_merge_symbol): Also skip definition from
an IR object.
(elf_link_add_object_symbols): If linker plugin is enabled, set
non_ir_ref_regular on symbols referenced in regular objects so
that linker plugin will get the correct symbol resolution.
ld/
PR ld/22502
* testsuite/ld-plugin/lto.exp: Run PR ld/22502 test.
* testsuite/ld-plugin/pr22502a.c: New file.
* testsuite/ld-plugin/pr22502b.c: Likewise.
The fix for PR 19291 broke some other cases where -r is used with scripts,
as reported in PR 22266. The original fix for PR 22266 ended up breaking
many cases for REL targets, where the addends are stored in the section data,
and are not being adjusted properly.
The problem was basically that in a relocatable output file (ET_REL),
symbol values are supposed to be relative to the start address of their
section. Usually in a relocatable file, all sections start at 0, so the
failure to get this right is often irrelevant, but with a linker script,
we occasionally see an output section whose starting address is not 0,
and gold would occasionally write a symbol with its relocated value instead
of its section-relative value.
This patch reverts the recent fix for PR 22266 as well as my original fix
for PR 19291. The original fix moved the symbol value adjustment to
write_local_symbols, but neglected to undo a few places where the adjustment
was also being applied, resulting in an occasional double adjustment. The
more recent fix removed those other adjustments, but then failed to
re-account for the adjustment when rewriting the relocations on REL targets.
With the old attempts reverted, we now apply the symbol value adjustment to
the one case that had been missed (non-section symbols in merge sections).
But now we also need to account for the adjustment when rewriting the addends
for RELA relocations.
gold/
PR gold/19291
PR gold/22266
* object.cc (Sized_relobj_file::compute_final_local_value_internal):
Revert changes from 2017-11-08 patch. Adjust symbol value in
relocatable links for non-section symbols.
(Sized_relobj_file::compute_final_local_value): Revert changes from
2017-11-08 patch.
(Sized_relobj_file::do_finalize_local_symbols): Likewise.
(Sized_relobj_file::write_local_symbols): Revert changes from
2015-11-25 patch.
* object.h (Sized_relobj_file::compute_final_local_value_internal):
Revert changes from 2017-11-08 patch.
* powerpc.cc (Target_powerpc::relocate_relocs): Adjust addend for
relocatable links.
* target-reloc.h (relocate_relocs): Adjust addend for relocatable links.
* testsuite/pr22266_a.c (hello): New function.
* testsuite/pr22266_main.c (main): Add test for merge sections.
* testsuite/pr22266_script.t: Add rule for .rodata.
This removes REMOTE_OBS from the Makefile. It is no longer needed, as
remote support is always built into gdb. The relevant sources are now
added to COMMON_SFILES, where they are treated like other ordinary
sources.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* Makefile.in (REMOTE_OBS): Remove.
(SFILES): Remove remote sources.
(COMMON_SFILES): Add remote sources.
(ALLDEPFILES): Remove dcache.c.
Move the object files corresponding to target/*.c to the target
subdirectory in the build tree.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* Makefile.in (SUBDIR_TARGET_SRCS, SUBDIR_TARGET_OBS): New
variables.
(SFILES): Use SUBDIR_TARGET_SRCS.
(COMMON_OBS): Use SUBDIR_TARGET_OBS. Remove waitstatus.o.
(CONFIG_SRC_SUBDIR): Add target.
(%.o): Remove target rule.
While working on the previous patch, I found a few .o files whose
corresponding .c file was not mentioned in Makefile.in. This patch
fixes the problem. I pulled this out separately to make it simpler to
review.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* Makefile.in (COMMON_OBS): Remove filename-seen-cache.o,
registry.o, thread-fsm.o, debug.o.
(COMMON_SFILES): Add filename-seen-cache.c, registry.c,
thread-fsm.c, debug.c.
This introduces a new COMMON_SFILES variable, and then defines some of
COMMON_OBS in terms of this new variable. This simpifies adding a new
ordinary source file.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* Makefile.in (COMMON_SFILES): New.
(SFILES): Move some entries to COMMON_SFILES.
(COMMON_OBS): Use COMMON_SFILES.
Change YYOBJ to be defined in terms of YYFILES.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* Makefile.in (YYFILES): Update comment.
(YYOBJ): Redefine.
Move the object files corresponding to python/*.c to the python
subdirectory in the build tree.
Because special CFLAGS are passed just to Python compilations, this
patch also required the addition of a pattern rule to update
INTERNAL_CFLAGS for here.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* Makefile.in (SUBDIR_PYTHON_OBS): Redefine.
(CONFIG_SRC_SUBDIR): Add python.
(%.o): Remove python rule.
(python/%.o): New rule.
* configure: Rebuild.
* configure.ac (CONFIG_OBS): Refer to python/python.o
Move the object files corresponding to guile/*.c to the guile
subdirectory in the build tree.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* configure: Rebuild.
* configure.ac (CONFIG_OBS): Refer to guile/guile.o.
* Makefile.in (SUBDIR_GUILE_OBS): Redefine.
(CONFIG_SRC_SUBDIR): Add guile.
(%.o): Remove guile rule.
Move the object files corresponding to unittests/*.c to the unittests
subdirectory in the build tree.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* Makefile.in (SUBDIR_UNITTESTS_OBS): Redefine.
(%.o): Remove unittests rule.
(CONFIG_SRC_SUBDIR): Add unittests.
Move the object files corresponding to tui/*.c to the tui subdirectory
in the build tree.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* Makefile.in (SUBDIR_TUI_OBS): Redefine.
(CONFIG_SRC_SUBDIR): Add tui.
(%.o): Remove tui rule.
Move the object files corresponding to compile/*.c to the compile
subdirectory in the build tree.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* Makefile.in (SUBDIR_GCC_COMPILE_OBS): Redefine.
(%.o): Remove compile rule.
(CONFIG_SRC_SUBDIR): Add compile.
Move object files corresponding to mi/*.c to a subdirectory in the
build tree.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* Makefile.in (SUBDIR_MI_OBS): Redefine.
(%.o): Remove mi rule.
(CONFIG_SRC_SUBDIR): Add mi.
(COMMON_OBS): Use mi/mi-common.o
Following the "arch" move, this moves the object files corresponding
to the cli/*.c source files to the "cli" build directory.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* Makefile.in (SUBDIR_CLI_OBS): Redefine.
(%.o): Remove cli rule.
(CONFIG_SRC_SUBDIR): Add cli.
This implements a simpler way to make the "arch" build directory --
namely, now it is done as an order-only dependency in the Makefile,
rather than being created when config.status is run. This simpler
because it means that the build directories can be changed without
re-running autoconf.
ChangeLog
2017-11-27 Tom Tromey <tom@tromey.com>
* configure.ac (CONFIG_SRC_SUBDIR): Don't subst.
* configure: Rebuild.
* Makefile.in (CONFIG_SRC_SUBDIR): Redefine.
(CONFIG_DEP_SUBDIR): New variable.
(%.o): Add order-only dependency.
($(CONFIG_DEP_SUBDIR)): New target.
find_trampoline_seg takes noticeable time when assembling source with
many sections. Cache the result of the most recent search and check it
first. No functional changes.
gas/
2017-11-27 Max Filippov <jcmvbkbc@gmail.com>
* config/tc-xtensa.c (find_trampoline_seg): Add static variable
that caches the result of the most recent search.
There is a recurring pattern in assembly files generated by a compiler
where a lot of jumps in a function are going to the same place. When
these jumps are relaxed with trampolines the assembler generates a
separate jump thread from each source.
Create an index of trampoline jump targets for each segment and see if a
jump being relaxed goes to a location from that index, in which case
replace its target with a location of existing trampoline jump that
results in the shortest path to the original target.
gas/
2017-11-27 Max Filippov <jcmvbkbc@gmail.com>
* config/tc-xtensa.c (trampoline_chain_entry, trampoline_chain)
(trampoline_chain_index): New structures.
(trampoline_index): Add chain_index field.
(xg_order_trampoline_chain_entry, xg_sort_trampoline_chain)
(xg_find_chain_entry, xg_get_best_chain_entry)
(xg_order_trampoline_chain, xg_get_trampoline_chain)
(xg_find_best_eq_target, xg_add_location_to_chain)
(xg_create_trampoline_chain, xg_get_single_symbol_slot): New
functions.
(xg_relax_fixups): Call xg_find_best_eq_target to adjust jump
target to point to an existing jump. Call
xg_create_trampoline_chain to create new jump target. Call
xg_add_location_to_chain to add newly created trampoline jump
to the corresponding chain.
(add_jump_to_trampoline): Extract loop searching for a single
slot with a symbol into a separate function, replace that code
with a call to that function.
(relax_frag_immed): Call xg_find_best_eq_target to adjust jump
target to point to an existing jump.
* testsuite/gas/xtensa/all.exp: Add trampoline-2 test.
* testsuite/gas/xtensa/trampoline.d: Adjust absolute addresses
as many duplicate trampoline chains are now coalesced.
* testsuite/gas/xtensa/trampoline.s: Add _nop so that objdump
stays in sync with instruction stream.
* testsuite/gas/xtensa/trampoline-2.l: New test result file.
* testsuite/gas/xtensa/trampoline-2.s: New test source file.
There's almost exact copy of the trampoline placement code in the
search_trampolines function that is used for jumps generated for relaxed
branch instructions. Get rid of the duplication and reuse
xg_find_best_trampoline function for that.
gas/
2017-11-27 Max Filippov <jcmvbkbc@gmail.com>
* config/tc-xtensa.c (search_trampolines, get_best_trampoline):
Remove definitions.
(xg_find_best_trampoline_for_tinsn): New function.
(relax_frag_immed): Replace call to get_best_trampoline with a
call to xg_find_best_trampoline_for_tinsn.
* testsuite/gas/xtensa/trampoline.d: Adjust absolute addresses
as the placement of trampolines for relaxed branches has been
changed.
Replace linked list of trampoline frags with an ordered array, so that
instead of indexing fixups trampolines could be indexed. Keep each array
in the trampoline_seg structure, so there's no need to rebuild it for
every new processed segment. Don't run relaxation for each trampoline
frag, instead run it for each fixup in the current segment that needs
relaxation at the beginning of each relaxation pass. This way the
complexity of this process drops from about O(n^2 * m) to about
O(log n * m), where n is the number of trampoline frags and m is the
number of fixups that need relaxation in the segment.
gas/
2017-11-27 Max Filippov <jcmvbkbc@gmail.com>
* config/tc-xtensa.c (trampoline_index): New structure.
(trampoline_seg): Replace trampoline list with trampoline index.
(xg_find_trampoline, xg_add_trampoline_to_index)
(xg_remove_trampoline_from_index, xg_add_trampoline_to_seg)
(xg_is_trampoline_frag_full, xg_get_fulcrum)
(xg_find_best_trampoline, xg_relax_fixup, xg_relax_fixups)
(xg_is_relaxable_fixup): New functions.
(J_MARGIN): New macro.
(xtensa_create_trampoline_frag): Use xg_add_trampoline_to_seg
instead of open-coded addition to the linked list.
(dump_trampolines): Iterate through the trampoline_seg::index.
(cached_fixupS, cached_fixup, fixup_cacheS, fixup_cache)
(fixup_order, xtensa_make_cached_fixup)
(xtensa_realloc_fixup_cache, xtensa_cache_relaxable_fixups)
(xtensa_find_first_cached_fixup, xtensa_delete_cached_fixup)
(xtensa_add_cached_fixup, check_and_update_trampolines): Remove
definitions.
(xg_relax_trampoline): Extract logic into separate functions,
replace body with a call to xg_relax_fixups.
(search_trampolines): Replace search in linked list with search
in index. Change data type of address-tracking variables from
int to offsetT. Replace abs with labs.
(xg_append_jump): Finish the trampoline frag if it's full.
(add_jump_to_trampoline): Remove trampoline frag from the index
if the frag is full.
* config/tc-xtensa.h (xtensa_frag_type): Remove next_trampoline.
* testsuite/gas/xtensa/trampoline.d: Adjust absolute addresses
as the placement of trampolines has slightly changed.
* testsuite/gas/xtensa/trampoline.s: Add _nop so that objdump
stays in sync with instruction stream.
The split between fragS and trampoline_frag doesn't save much space, but
makes trampolines management much more awkward. Merge trampoline_frag
data into the xtensa_frag_type, which is a part of fragS. No functional
changes.
gas/
2017-11-27 Max Filippov <jcmvbkbc@gmail.com>
* config/tc-xtensa.c (init_trampoline_frag): Replace pointer to
struct trampoline_frag parameter with pointer to fragS.
(xg_append_jump): Remove jump_around parameter.
(struct trampoline_frag): Remove.
(struct trampoline_seg): Change type of trampoline_list from
struct trampoline_frag to fragS.
(xtensa_create_trampoline_frag): Don't allocate struct
trampoline_frag. Initialize new fragS::tc_frag_data fields.
(dump_trampolines, xg_relax_trampoline, search_trampolines)
(get_best_trampoline, init_trampoline_frag)
(add_jump_to_trampoline, relax_frag_immed): Replace pointer to
struct trampoline_frag with a pointer to fragS.
(xg_append_jump): Remove jump_around parameter, use
fragS::tc_frag_data.jump_around_fix instead.
(xg_relax_trampoline, init_trampoline_frag)
(add_jump_to_trampoline): Don't pass jump_around parameter to
xg_append_jump.
* config/tc-xtensa.h (struct xtensa_frag_type): Add new fields:
needs_jump_around, next_trampoline and jump_around_fix.
xtensa_create_trampoline_frag has opencoded fragment equivalent to
find_trampoline_seg. Drop the fragment and use find_trampoline_seg
instead. No functional changes.
gas/
2017-11-27 Max Filippov <jcmvbkbc@gmail.com>
* config/tc-xtensa.c (find_trampoline_seg): Move above the first
use.
(xtensa_create_trampoline_frag): Replace trampoline seg search
code with a call to find_trampoline_seg.
init_trampoline_frag, add_jump_to_trampoline and xg_relax_trampoline add
a jump to the end of a trampoline frag. Extract it into a separate
funciton and use it in all these places. No functional changes.
gas/
2017-11-27 Max Filippov <jcmvbkbc@gmail.com>
* config/tc-xtensa.c (xg_append_jump): New function.
(xg_relax_trampoline, init_trampoline_frag)
(add_jump_to_trampoline): Replace trampoline jump assembling
code with a call to xg_append_jump.
To make measurement and changes easier extract trampoline relaxation
function. No functional changes.
gas/
2017-11-27 Max Filippov <jcmvbkbc@gmail.com>
* config/tc-xtensa.c (xg_relax_trampoline): New function.
(xtensa_relax_frag): Replace trampoline relaxation code with a
call to xg_relax_trampoline.
The following patch introduced a new feature related to Ada exception
catchpoints:
commit e547c119d0
Author: Joel Brobecker <brobecker@adacore.com>
Date: Fri Nov 24 17:09:42 2017 -0500
Subject: (Ada) provide the exception message when hitting an exception catchpoint
Unfortunately, the patch left 2 errors in gdb.ada/mi_catch_ex.exp,
both inside the "continue_to_exception" function:
1. The exception message on the console can include the exception
message, and thus this patch adjust the expected output in
the corresponding gdb_expect call to allow it;
to allow it.
2. There was a TCL syntax confusion in "$exception_name(..."
that caused TCL to evaluate "exception_name as an array,
rather than as a variable. This patch fixes this by escaping
the '(' (and the corresponding closing parenthesis, for
consistency).
gdb/testsuite/ChangeLog:
* gdb.ada/mi_catch_ex.exp (continue_to_exception): Adjust
expected output in gdb_expect call to allow the exception
message to be present as well. Fix syntax confusion to avoid
TCL thinking that exception_name is an array.
Tested on x86_64-linux, with:
DejaGnu version 1.6
Expect version 5.45
Tcl version 8.6
No dynamic relocs are needed for TLS defined in an executable, the
TP relative offset is known at link time.
Fixes
FAIL: Build pr22263-1
bfd/
PR ld/22263
* elfnn-aarch64.c (elfNN_aarch64_relocate_section): Use
bfd_link_executable instead of bfd_link_pic for TLS.
(elfNN_aarch64_allocate_dynrelocs): Likewise.
(aarch64_can_relax_tls): Likewise.
With static pie linking undefined weak symbols are forced to resolve locally
to 0, so no GOT setup is needed in elfNN_aarch64_finish_dynamic_symbol,
which previously failed for these symbols.
The failure caused the unhelpful error message:
"ld: final link failed: Nonrepresentable section on output"
bfd/
PR ld/22269
* elfnn-aarch64.c (elfNN_aarch64_finish_dynamic_symbol): Use
UNDEFWEAK_NO_DYNAMIC_RELOC to avoid dynamic GOT relocs.
(elfNN_aarch64_allocate_dynrelocs): Likewise.
PR 22490
* readelf.c (dump_section_as_bytes): Check for a NULL string
section pointer.
(process_notes_at): Compute the alignment to use if displaying
notes from a segment.
This patch updates the `find` command help and docs description to show
how to search for not null terminated strings when current language's
strings includes it.
gdb/ChangeLog:
PR gdb/21945
* findcmd.c (_initialize_mem_search): Update find command help
text.
gdb/doc/ChangeLog:
PR gdb/21945
* gdb.texinfo (Search Memory): Update description and example
about how to search a string without NULL terminator.
While playing with valgrind, I noticed that with Python 3, the progname
variable in do_start_initialization is not being freed (concat returns a
malloc'ed string). This patch uses unique_xmalloc_ptr to manage it.
With Python 2, we pass progname it directly to Py_SetProgramName, so it
should not be freed. We therefore release it before passing it.
gdb/ChangeLog:
* python/python.c (do_start_initialization): Change progname
type to gdb::unique_xmalloc_ptr. Release the pointer when using
Python 2.
This fixed the build with GCC 4.2:
cc1: warnings being treated as errors
binutils-gdb/binutils/dwarf.c: In function ‘load_separate_debug_info’:
binutils-gdb/binutils/dwarf.c:9650: warning: declaration of ‘link’ shadows a global declaration
/usr/include/unistd.h:757: warning: shadowed declaration is here
* dwarf.c (load_separate_debug_info): Rename argument name from
link to xlink.
This changes maybe_disable_address_space_randomization to be an RAII
class, rather than having it return a cleanup.
Regression tested by the buildbot.
ChangeLog
2017-11-26 Tom Tromey <tom@tromey.com>
* nat/linux-personality.h (class
maybe_disable_address_space_randomization): New class.
(maybe_disable_address_space_randomization): Don't declare
function.
* nat/linux-personality.c (restore_personality)
(make_disable_asr_cleanup): Remove.
(maybe_disable_address_space_randomization): Now a constructor.
(~maybe_disable_address_space_randomization): New destructor.
* linux-nat.c (linux_nat_create_inferior): Update.
gdbserver/ChangeLog
2017-11-26 Tom Tromey <tom@tromey.com>
* linux-low.c (linux_create_inferior): Update.
This removes a cleanup from gcore.c, replacing it with
unique_xmalloc_ptr.
Regression tested by the buildbot.
ChangeLog
2017-11-26 Tom Tromey <tom@tromey.com>
* gcore.c (write_gcore_file_1): Use gdb::unique_xmalloc_ptr.
The SPU-specific test cases were not modified to use standard_output_file
and therefore all were no longer being executed. Fixing this exposed a
few other bugs in spu-info noticed by using a more recent compiler, which
are also fixed here.
gdb/testsuite/ChangeLog:
2017-11-26 Ulrich Weigand <uweigand@de.ibm.com>
* gdb.arch/spu-info.c: Include <unistd.h>.
(do_signal_test): Fix broken calls to write.
* gdb.arch/spu-info.exp: Use prepare_for_testing.
Fix checks for empty mailboxes. Update signal tests for corrected
do_signal_test routine. Allow nonzero event status.
Switching spu_software_single_step to use a regcache instead of a frame:
https://sourceware.org/ml/gdb-patches/2016-11/msg00355.html
cause a serious regression to SPU single-stepping.
There were two separate problems:
- SPU_LSLR_REGNUM is a pseudo register, so we must use the "cooked"
regcache methods instead of the "raw" ones to access it.
- When accessing a branch target register, we must only use the first
four bytes of the 16-byte vector register. This was done automatically
by the frame routines, but not by the regcache routines.
gdb/ChangeLog:
2017-11-26 Ulrich Weigand <uweigand@de.ibm.com>
* spu-tdep.c (spu_software_single_step): Access SPU_LSLR_REGNUM as
"cooked" register. Access only first four bytes of branch target
registers.
Pedro has kindly pointed out that
gdb.arch/amd64-stap-optional-prefix.exp was failing after my
C++-ification patches touching the probe interface. The failure is
kind of cryptic:
77 break -pstap bar
78 Breakpoint 3 at 0x40048d
79 (gdb) PASS: gdb.arch/amd64-stap-optional-prefix.exp: bar: break -pstap bar
80 continue
81 Continuing.
82
83 Program received signal SIGILL, Illegal instruction.
84 main () at amd64-stap-optional-prefix.S:26
85 26 STAP_PROBE1(probe, foo, (%rsp))
It took me a while to figure out where this SIGILL is coming from.
Initially I thought it was something related to writing registers to
the inferior when dealing with probe arguments, but I discarded this
since the arguments were not touching any registers.
In the end, this was a mistake that was introduced during the review
process of the patch. When setting/clearing a SystemTap probe's
semaphore, the code was using 'm_address' (which refers the probe's
address) instead of 'm_sem_addr' (which refers to the semaphore's
address). This caused GDB to write a bogus value in the wrong memory
position, which in turn caused the SIGILL.
I am pushing this patch to correct the mistake.
On a side note: I told Pedro that the BuildBot hadn't caught the
failure during my try build, and for a moment there was a suspicion
that the BuildBot might be at fault here. However, I investigate this
and noticed that I only did one try build, with a patch that was
correctly using 'm_sem_addr' where applicable, and therefore no
failure should have happened indeed. I probably should have requested
another try build after addressing the review's comments, but they
were mostly basic and I didn't think it was needed. Oh, well.
2017-11-25 Sergio Durigan Junior <sergiodj@redhat.com>
PR gdb/22491
* stap-probe.c (relocate_address): New function.
(stap_probe::get_relocated_address): Use 'relocate_address'.
(stap_probe::set_semaphore): Use 'relocate_address' and pass
'm_sem_addr'.
(stap_probe::clear_semaphore): Likewise.
The support for setting breakpoint in functions with ABI tags patch
will add a use of SYMBOL_HASH_NEXT in cp-support.c, which fails to
compile with:
src/gdb/cp-support.c:38:0:
src/gdb/cp-support.c: In function ‘unsigned int cp_search_name_hash(const char*)’:
src/gdb/../include/safe-ctype.h:148:20: error: ‘do_not_use_tolower_with_safe_ctype’ was not declared in this scope
#define tolower(c) do_not_use_tolower_with_safe_ctype
^
src/gdb/minsyms.h:174:18: note: in expansion of macro ‘tolower’
((hash) * 67 + tolower ((unsigned char) (c)) - 113)
^
src/gdb/cp-support.c:1677:14: note: in expansion of macro ‘SYMBOL_HASH_NEXT’
hash = SYMBOL_HASH_NEXT (hash, *string);
^
This fixes the problem before it happens.
I was somewhat worried about whether this might have an impact with
languages that are case insensitive, but I convinced myself that it
doesn't. As bonus, this improves GDB's minsym interning performance a
bit (3%-10%). See
<https://sourceware.org/ml/gdb/2017-11/msg00021.html>.
gdb/ChangeLog:
2017-11-25 Pedro Alves <palves@redhat.com>
* dictionary.c: Include "safe-ctype.h".
* minsyms.c: Include "safe-ctype.h".
* minsyms.c (SYMBOL_HASH_NEXT): Use TOLOWER instead of tolower.
