Alan Modra [Tue, 7 Apr 2015 12:53:21 +0000 (22:23 +0930)]
Modify get_reloc_section for targets that map .got.plt to .got
Fixes tic6x testsuite failures due to .rela.plt having a zero sh_info.
I considered passing link_info to get_reloc_section so we could
directly return the .got.plt output section, but we need the fallback
to name lookup anyway for objcopy.
Alan Modra [Tue, 31 Mar 2015 23:29:46 +0000 (09:59 +1030)]
PowerPC non-PIC to PIC editing for protected var access
This is a linker-only solution to the incompatibility between shared
library protected visibility variables and using .dynbss and copy
relocs for non-PIC access to shared library variables.
bfd/
* elf32-ppc.c (struct ppc_elf_link_hash_entry): Add has_addr16_ha
and has_addr16_lo. Make has_sda_refs a bitfield.
(ppc_elf_check_relocs): Set new flags.
(ppc_elf_link_hash_table_create): Update default_params.
(ppc_elf_adjust_dynamic_symbol): Clear protected_def in cases
where we won't be making .dynbss entries or editing code. Set
params->pic_fixup when we'll edit code for protected var access.
(allocate_dynrelocs): Allocate got entry for edited code and
discard dyn_relocs.
(struct ppc_elf_relax_info): Add picfixup_size.
(ppc_elf_relax_section): Rename struct one_fixup to struct
one_branch_fixup. Rename fixups to branch_fixups. Size space for
pic fixups.
(ppc_elf_relocate_section): Edit non-PIC accessing protected
visibility variables to PIC. Don't emit dyn_relocs for code
we've edited.
* elf32-ppc.h (struct ppc_elf_params): Add pic_fixup.
ld/
* emultempl/ppc32elf.em: Handle --no-pic-fixup.
(params): Init new field.
(ppc_before_allocation): Enable relaxation for pic_fixup.
Pedro Alves [Tue, 7 Apr 2015 10:42:09 +0000 (11:42 +0100)]
Displaced stepping debug: fetch the right regcache
Although not currently possible in practice when we get here,
'resume_ptid' can also be a wildcard throughout this function. It's
clearer to fetch the regcache using the thread's ptid.
gdb/ChangeLog:
2015-04-07 Pedro Alves <pedro@codesourcery.com>
* infrun.c (resume) <displaced stepping debug output>: Get the
leader thread's regcache, not resume_ptid's.
Yao Qi [Tue, 7 Apr 2015 10:30:07 +0000 (11:30 +0100)]
Properly set alarm value in gdb.threads/non-stop-fair-events.exp
Nowadays, the alarm value is 60, and alarm is generated on some slow
boards. This patch is to pass DejaGNU timeout value to the program,
and move the alarm call before going to infinite loop. If any thread
has activities, the alarm is reset.
gdb/testsuite:
2015-04-07 Yao Qi <yao.qi@linaro.org>
* gdb.threads/non-stop-fair-events.c (SECONDS): New macro.
(child_function): Call alarm.
(main): Move call to alarm into the loop.
* gdb.threads/non-stop-fair-events.exp: Build program with
-DTIMEOUT=$timeout.
* lib/pascal.exp (gpc_compile): Rename dest arg to destfile.
The "dest" parameter to fpc_compile/gpc_compile is the name of
compilation destination file, not a board name.
This patch fixes this by using names consistent with
lib/future.exp:gdb_default_target_compile.
gdb/testsuite/ChangeLog:
* lib/pascal.exp (gpc_compile): Rename dest arg to destfile.
Fix dest parameter to board_info.
(fpc_compile): Ditto.
(gdb_compile_pascal): Rename dest arg to destfile.
symtab.c (hash_symbol_entry): Hash STRUCT_DOMAIN symbols as VAR_DOMAIN.
gdb/ChangeLog:
* symtab.c (hash_symbol_entry): Hash STRUCT_DOMAIN symbols as
VAR_DOMAIN.
(symbol_cache_lookup): Clarify use of bsc_ptr, slot_ptr parameters.
Include symbol domain in debugging output.
Pedro Alves [Mon, 6 Apr 2015 11:35:18 +0000 (12:35 +0100)]
Fallback to stub-termcap.c on all hosts
Currently building gdb is impossible without an installed termcap or
curses library. But, GDB already has a very minimal termcap in the
tree to handle this situation for Windows -- gdb/stub-termcap.c. This
patch makes that the fallback for all hosts.
Testing this on GNU/Linux (by simply hacking away the termcap/curses
detection in gdb/configure.ac), we trip on:
../readline/libreadline.a(terminal.o): In function `_rl_init_terminal_io':
/home/pedro/gdb/mygit/src/readline/terminal.c:527: undefined reference to `PC'
/home/pedro/gdb/mygit/src/readline/terminal.c:528: undefined reference to `BC'
/home/pedro/gdb/mygit/src/readline/terminal.c:529: undefined reference to `UP'
/home/pedro/gdb/mygit/src/readline/terminal.c:538: undefined reference to `PC'
/home/pedro/gdb/mygit/src/readline/terminal.c:539: undefined reference to `BC'
/home/pedro/gdb/mygit/src/readline/terminal.c:540: undefined reference to `UP'
These are globals that are normally defined by termcap (or ncurses'
termcap emulation).
Now, we could just define replacements in stub-termcap.c, but
readline/terminal.c (at least the copy in our tree) has this:
which can result in readline defining the globals too. That will
usually work out in C, given that "-fcommon" is usually the default
for C compilers, but that won't work for C++, or C with -fno-common
(link fails with "multiple definition" errors)...
Mirroring those #ifdef conditions in the stub termcap screams
"brittle" to me -- I can see them changing in latter readline
versions.
Work around that by simply using __attribute__((weak)).
Windows/PE/COFF's do support weak, but not on gcc 3.4 based toolchains
(4.8.x does work). Given the file never needed the variables while it
was Windows-only, just continue not defining them there. All other
supported hosts should support this.
gdb/ChangeLog:
2015-04-06 Pedro Alves <palves@redhat.com>
Bernd Edlinger <bernd.edlinger@hotmail.de>
* configure.ac: Remove the mingw32-specific stub-termcap.o
fallback, and instead fallback to the stub termcap on all hosts.
* configure: Regenerate.
* stub-termcap.c [!__MINGW32__] (PC, BC, UP): Define as weak
symbols.
It also checks the compression header when decompressing the compressed
section.
* readelf.c (get_elf_section_flags): Support SHF_COMPRESSED.
(get_compression_header): New.
(process_section_headers): Dump compression header if needed.
(uncompress_section_contents): Don't free compressed_buffer here.
(load_specific_debug_section): Free the compressed buffer, update
the section buffer and the section size if uncompress is
successful.
H.J. Lu [Sun, 5 Apr 2015 15:11:11 +0000 (08:11 -0700)]
Xfail the compressed debug sections
There is no need to generate compressed debug section if compressed
section size is the same as before compression. We should xfail the
compressed debug section test if there are no compressed sections
binutils/testsuite/
* binutils-all/compress.exp (compression_used): New.
Xfail test if compression didn't make the section smaller.
gas/
2015-04-05 H.J. Lu <hongjiu.lu@intel.com>
* write.c (compress_debug): Don't write the zlib header if
compressed section size is the same as before compression.
Mike Frysinger [Sun, 5 Apr 2015 08:37:44 +0000 (04:37 -0400)]
sim: moxie: fix running after nrun conversion
The nrun conversion was slightly incorrect in how it stopped when an
exception occurred. We still set cpu.asregs.exception, but nothing
was checking it anymore. Convert all of that to sim_engine_halt.
To keep things from regressing again, add a basic testsuite too.
H.J. Lu [Sat, 4 Apr 2015 14:18:17 +0000 (07:18 -0700)]
Add a dw2-3.S test
This patch adds a dw2-3.S test for upcoming SHF_COMPRESSED test. The
existing dw2-1.S/dw2-2.S tests generate non-compressed debug sections
for SHF_COMPRESSED since SHF_COMPRESSED compressed debug sections are
bigger.
Even when referenced types are dynamic, the corresponding referencing
type should not be considered as dynamic: it's only a pointer. This
prevents reference type for values not in memory to be resolved.
gdb/ChangeLog:
* gdbtypes.c (is_dynamic_type_internal): Remove special handling
of TYPE_CODE_REF types so that they are not considered as
dynamic depending on the referenced type.
(resolve_dynamic_type_internal): Likewise.
gdb/testsuite/ChangeLog:
* gdb.ada/funcall_ref.exp: New file.
* gdb.ada/funcall_ref/foo.adb: New file.
Mike Frysinger [Fri, 3 Apr 2015 00:15:43 +0000 (20:15 -0400)]
sim: d10v: fix signal updates
Way back in aba6488e0b73756f31f154d12a228baa82a68d8a, a bunch of signal
defines were changed to TARGET_SIGNAL_xxx. For d10v, the transition was
incomplete which lead to sim_stop_reason using the new set but sim_resume
still using the old set. Which meant in some cases, the sim would never
actually stop.
Convert all the remaining SIGxxx defines in here to TARGET_SIGNAL_xxx.
This has the nice side effect of fixing the testsuite.
Renlin Li [Thu, 2 Apr 2015 13:59:45 +0000 (14:59 +0100)]
[AArch64] Emit DATA_MAP in order within text section
2015-03-27 Renlin Li <renlin.li@arm.com>
gas/
* config/tc-aarch64.c (mapping_state): Emit MAP_DATA within text section in order.
(mapping_state_2): Don't emit MAP_DATA here.
(s_aarch64_inst): Align frag during state transition.
(md_assemble): Likewise.
[Thread 1081] #1 stopped.
(gdb) FAIL: gdb.threads/no-unwaited-for-left.exp: continue stops when the main thread exits
I checked the gdb.log on buildbot, and find that these two fails also
appear on Debian-i686-native-extended-gdbserver and Fedora-ppc64be-native-gdbserver-m64.
I recall that they are about local/remote parity, and related RSP is missing.
There has been already a PR 14618 about it. This patch is to kfail them
on remote target.
gdb/testsuite:
2015-04-02 Yao Qi <yao.qi@linaro.org>
* gdb.threads/no-unwaited-for-left.exp: Set up kfail if target
is remote.
Gary Benson [Thu, 2 Apr 2015 12:38:29 +0000 (13:38 +0100)]
Update exec_file_attach to cope with "target:" filenames
This commit adds support for filenames prefixed with "target:" to
exec_file_attach. This is required to correctly follow inferior
exec* calls when a gdb_sysroot prefixed with "target:" is set.
gdb/ChangeLog:
* exec.c (exec_file_attach): Support "target:" filenames.
Gary Benson [Thu, 2 Apr 2015 12:38:29 +0000 (13:38 +0100)]
Strip "target:" prefix in solib_find if accessing local files
This commit updates solib_find to strip the "target:" prefix from
gdb_sysroot when accessing local files. This ensures that the same
search algorithm is used for local files regardless of whether a
"target:" prefix was used or not. It also avoids cluttering GDB's
output with unnecessary "target:" prefixes on paths.
gdb/ChangeLog:
* solib.c (solib_find): Strip "target:" prefix from sysroot
if accessing local files.
Gary Benson [Thu, 2 Apr 2015 12:38:29 +0000 (13:38 +0100)]
Convert "remote:" sysroots to "target:" and remove "remote:"
The functionality of "target:" sysroots is a superset of the
functionality of "remote:" sysroots. This commit causes the
"set sysroot" command to rewrite "remote:" sysroots as "target:"
sysroots and replaces "remote:" specific code with "target:"
specific code where still necessary.
gdb/ChangeLog:
* remote.h (REMOTE_SYSROOT_PREFIX): Remove definition.
(remote_filename_p): Remove declaration.
(remote_bfd_open): Likewise.
* remote.c (remote_bfd_iovec_open): Remove function.
(remote_bfd_iovec_close): Likewise.
(remote_bfd_iovec_pread): Likewise.
(remote_bfd_iovec_stat): Likewise.
(remote_filename_p): Likewise.
(remote_bfd_open): Likewise.
* symfile.h (gdb_bfd_open_maybe_remote): Remove declaration.
* symfile.c (separate_debug_file_exists): Use gdb_bfd_open.
(gdb_bfd_open_maybe_remote): Remove function.
(symfile_bfd_open): Replace remote filename check with
target filename check.
(reread_symbols): Use gdb_bfd_open.
* build-id.c (gdbcore.h): New include.
(build_id_to_debug_bfd): Use gdb_bfd_open.
* infcmd.c (attach_command_post_wait): Remove remote filename
check.
* solib.c (solib_find): Replace remote-specific handling with
target-specific handling. Update comments where necessary.
(solib_bfd_open): Replace remote-specific handling with
target-specific handling.
(gdb_sysroot_changed): New function.
(_initialize_solib): Call the above when gdb_sysroot changes.
* windows-tdep.c (gdbcore.h): New include.
(windows_xfer_shared_library): Use gdb_bfd_open.
Gary Benson [Thu, 2 Apr 2015 12:38:29 +0000 (13:38 +0100)]
Make gdb_bfd_open able to open BFDs using target fileio
This commit updates gdb_bfd_open to access files using target
fileio functions if the supplied path starts with "target:"
and if the local and target filesystems are not the same.
This allows users to specify "set sysroot target:" and have
GDB access files locally or from the remote as appropriate.
The new functions in gdb_bfd.c are copies of functions from
remote.c. This duplication is intentional and will be removed
by the next commit in this series.
gdb/ChangeLog:
* gdb/gdb_bfd.h (TARGET_SYSROOT_PREFIX): New definition.
(is_target_filename): New declaration.
(gdb_bfd_has_target_filename): Likewise.
(gdb_bfd_open): Update documentation comment.
* gdb_bfd.c (target.h): New include.
(gdb/fileio.h): Likewise.
(is_target_filename): New function.
(gdb_bfd_has_target_filename): Likewise.
(fileio_errno_to_host): Likewise.
(gdb_bfd_iovec_fileio_open): Likewise.
(gdb_bfd_iovec_fileio_pread): Likewise.
(gdb_bfd_iovec_fileio_close): Likewise.
(gdb_bfd_iovec_fileio_fstat): Likewise.
(gdb_bfd_open): Use target fileio to access paths prefixed
with "target:" where necessary.
Gary Benson [Thu, 2 Apr 2015 12:38:28 +0000 (13:38 +0100)]
Introduce target_filesystem_is_local
This commit introduces a new target method target_filesystem_is_local
which can be used to determine whether or not the filesystem accessed
by the target_fileio_* methods is the local filesystem.
gdb/ChangeLog:
* target.h (struct target_ops) <to_filesystem_is_local>:
New field.
(target_filesystem_is_local): New macro.
* target-delegates.c: Regenerate.
* remote.c (remote_filesystem_is_local): New function.
(init_remote_ops): Initialize to_filesystem_is_local.
* Makefile.in (SUBDIR_PYTHON_OBJS): Add py-unwind.o.
(SUBDIR_PYTHON_SRCS): Add py-unwind.c.
(py-unwind.o): New recipe.
* NEWS: mention Python frame unwinding.
* data-directory/Makefile.in (PYTHON_FILE_LIST): Add
gdb/unwinder.py and gdb/command/unwinder.py
* python/lib/gdb/__init__.py (packages): Add frame_unwinders
list.
(execute_unwinders): New function.
* python/lib/gdb/command/unwinders.py: New file.
* python/lib/gdb/unwinder.py: New file.
* python/py-objfile.c (objfile_object): Add frame_unwinders field.
(objfpy_dealloc): Decrement frame_unwinders reference count.
(objfpy_initialize): Create frame_unwinders list.
(objfpy_get_frame_unwinders): New function.
(objfpy_set_frame_unwinders): Ditto.
(objfile_getset): Add frame_unwinders attribute to Objfile.
* python/py-progspace.c (pspace_object): Add frame_unwinders field.
(pspy_dealloc): Decrement frame_unwinders reference count.
(pspy_initialize): Create frame_unwinders list.
(pspy_get_frame_unwinders): New function.
(pspy_set_frame_unwinders): Ditto.
(pspy_getset): Add frame_unwinders attribute to gdb.Progspace.
* python/py-unwind.c: New file.
* python/python-internal.h (pspy_get_name_unwinders): New prototype.
(objpy_get_frame_unwinders): New prototype.
(gdbpy_initialize_unwind): New prototype.
* python/python.c (gdbpy_apply_type_printers): Call
gdbpy_initialize_unwind.
gdb/doc/ChangeLog:
* doc/python.texi (Writing a Frame Unwinder in Python): Add
section.
gdb/testsuite/ChangeLog:
* gdb.python/py-unwind-maint.c: New file.
* gdb.python/py-unwind-maint.exp: New test.
* gdb.python/py-unwind-maint.py: New file.
* gdb.python/py-unwind.c: New file.
* gdb.python/py-unwind.exp: New test.
* gdb.python/py-unwind.py: New test.
Pedro Alves [Mon, 30 Mar 2015 15:39:56 +0000 (16:39 +0100)]
infrun.c:resume: currently_stepping after clearing stepped_breakpoint
My all-stop-on-top-of-non-stop series manages to shows regressions due
to this latent bug. currently_stepping returns true if
stepped_breakpoint is set. Obviously we should clear
it before checking currently_stepping, not after.
Tested on x86_64 Fedora 20.
gdb/ChangeLog:
2015-04-01 Pedro Alves <palves@redhat.com>
* infrun.c (resume): Check currently_stepping after clearing
stepped_breakpoint, not before.
H.J. Lu [Wed, 1 Apr 2015 13:24:42 +0000 (06:24 -0700)]
Regenerate configure in gold
Regenerate configure for zlib.m4 change, which adds --with-system-zlib and
removes --with-zlib in gold. zlib is enabled unconditionally with builtin
zlib imported from GCC.
Pedro Alves [Tue, 24 Mar 2015 14:24:53 +0000 (14:24 +0000)]
linux_nat.c: Mark new thread running even if momentarily pausing
My all-stop-on-top-of-non-stop series manages to trip on a bug in the
linux-nat.c backend while running the testsuite. If a thread is
discovered while threads are being momentarily paused (without the
core's intervention), the thread ends up stuck in THREAD_STOPPED
state, even though from the user's perspective, the thread is running
even while it is paused.
From inspection, in the current sources, this can happen if we call
stop_and_resume_callback, though there's no way to test that with
current Linux kernels.
(While trying to come up with test to exercise this, I stumbled on:
https://sourceware.org/ml/gdb-patches/2015-03/msg00850.html
... which does include a non-trivial test, so I think I can still
claim I come out net positive. :-) )
Tested on x86_64 Fedora 20.
gdb/ChangeLog:
2015-04-01 Pedro Alves <palves@redhat.com>
Pedro Alves [Wed, 1 Apr 2015 12:38:06 +0000 (13:38 +0100)]
Crash on thread id wrap around
On GNU/Linux, if the target reuses the TID of a thread that GDB still
has in its list marked as THREAD_EXITED, GDB crashes, like:
(gdb) continue
Continuing.
src/gdb/thread.c:789: internal-error: set_running: Assertion `tp->state != THREAD_EXITED' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n) FAIL: gdb.threads/tid-reuse.exp: continue to breakpoint: after_reuse_time (GDB internal error)
Here:
(top-gdb) bt
#0 internal_error (file=0x953dd8 "src/gdb/thread.c", line=789, fmt=0x953da0 "%s: Assertion `%s' failed.")
at src/gdb/common/errors.c:54
#1 0x0000000000638514 in set_running (ptid=..., running=1) at src/gdb/thread.c:789
#2 0x00000000004bda42 in linux_handle_extended_wait (lp=0x16f5760, status=0, stopping=0) at src/gdb/linux-nat.c:2114
#3 0x00000000004bfa24 in linux_nat_filter_event (lwpid=20570, status=198015) at src/gdb/linux-nat.c:3127
#4 0x00000000004c070e in linux_nat_wait_1 (ops=0xe193d0, ptid=..., ourstatus=0x7fffffffd2c0, target_options=1) at src/gdb/linux-nat.c:3478
#5 0x00000000004c1015 in linux_nat_wait (ops=0xe193d0, ptid=..., ourstatus=0x7fffffffd2c0, target_options=1) at src/gdb/linux-nat.c:3722
#6 0x00000000004c92d2 in thread_db_wait (ops=0xd80b60 <thread_db_ops>, ptid=..., ourstatus=0x7fffffffd2c0, options=1)
at src/gdb/linux-thread-db.c:1525
#7 0x000000000066db43 in delegate_wait (self=0xd80b60 <thread_db_ops>, arg1=..., arg2=0x7fffffffd2c0, arg3=1) at src/gdb/target-delegates.c:116
#8 0x000000000067e54b in target_wait (ptid=..., status=0x7fffffffd2c0, options=1) at src/gdb/target.c:2206
#9 0x0000000000625111 in fetch_inferior_event (client_data=0x0) at src/gdb/infrun.c:3275
#10 0x0000000000648a3b in inferior_event_handler (event_type=INF_REG_EVENT, client_data=0x0) at src/gdb/inf-loop.c:56
#11 0x00000000004c2ecb in handle_target_event (error=0, client_data=0x0) at src/gdb/linux-nat.c:4655
I managed to come up with a test that reliably reproduces this. It
spawns enough threads for the pid number space to wrap around, so
could potentially take a while. On my box that's 4 seconds; on
gcc110, a PPC box which has max_pid set to 65536, it's over 10
seconds. So I made the test compute how long that would take, and cap
the time waited if it would be unreasonably long.
Tested on x86_64 Fedora 20.
gdb/ChangeLog:
2015-04-01 Pedro Alves <palves@redhat.com>
* linux-thread-db.c (record_thread): Readd the thread to gdb's
list if it was marked exited.
gdb/testsuite/ChangeLog:
2015-04-01 Pedro Alves <palves@redhat.com>
* gdb.threads/tid-reuse.c: New file.
* gdb.threads/tid-reuse.exp: New file.
Marcus Shawcroft [Tue, 24 Feb 2015 12:04:41 +0000 (12:04 +0000)]
[AArch64] Workaround for Cortex A53 erratum 843419
Some early revisions of the Cortex-A53 have an erratum (843419). The
details of the erratum are quite complex and involve dynamic
conditions. For the purposes of the workaround we have simplified the
static conditions to an ADRP in the last two instructions of a 4KByte
page, followed within four instructions by a load/store dependent on
the ADRP.
This patch adds support to conservatively scan for and workaround
Cortex A53 erratum 843419. There are two different workaround
strategies used. The first is to rewrite ADRP instructions which form
part of an erratum sequence with an ADR instruction. In situations
where the ADR provides insufficient offset the dependent load or store
instruction from the sequence is moved to a stub section and branches
are inserted from the original sequence to the relocated instruction
and back again.
Stub section sizes are rounded up to a multiple of 4096 in order to
ensure that the act of inserting work around stubs does not create
more errata sequences.
Workaround stubs are always inserted into the stub section associated
with the input section containing the erratum sequence. This ensures
that the fully relocated form of the veneered load store instruction
is available at the point in time when the stub section is written.
Pedro Alves [Wed, 1 Apr 2015 10:01:44 +0000 (11:01 +0100)]
GDBServer: give more complete usage information
--attach/--multi are currently only mentioned on the usage info first
lines, the meaning of PROG is completely absent and the COMM text does
not mention '-/stdio'.
A few options are missing:
. --disable-randomization / --no-disable-randomization is not mentioned.
Although the manual has a comment saying these are superceded by
QDisableRandomization, that only makes sense for "run" in
extended-remote mode. When we start gdbserver passing it a PROG,
--disable-randomization / --no-disable-randomization do take effect.
So I think we should document these.
. We show --debug / --remote-debug, so might as well show --disable-packet too.
GDB's --help has this "For more information, consult the GDB manual"
blurb that is missing in GDBserver's --help.
Then shuffle things around a bit into "Operating modes", "Other
options" and "Debug options" sections, similarly to GDB's --help
structure.
Before:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
$ ./gdbserver/gdbserver --help
Usage: gdbserver [OPTIONS] COMM PROG [ARGS ...]
gdbserver [OPTIONS] --attach COMM PID
gdbserver [OPTIONS] --multi COMM
COMM may either be a tty device (for serial debugging), or
HOST:PORT to listen for a TCP connection.
Options:
--debug Enable general debugging output.
--debug-format=opt1[,opt2,...]
Specify extra content in debugging output.
Options:
all
none
timestamp
--remote-debug Enable remote protocol debugging output.
--version Display version information and exit.
--wrapper WRAPPER -- Run WRAPPER to start new programs.
--once Exit after the first connection has closed.
Report bugs to "<http://www.gnu.org/software/gdb/bugs/>".
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
After:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
$ ./gdbserver/gdbserver --help
Usage: gdbserver [OPTIONS] COMM PROG [ARGS ...]
gdbserver [OPTIONS] --attach COMM PID
gdbserver [OPTIONS] --multi COMM
COMM may either be a tty device (for serial debugging),
HOST:PORT to listen for a TCP connection, or '-' or 'stdio' to use
stdin/stdout of gdbserver.
PROG is the executable program. ARGS are arguments passed to inferior.
PID is the process ID to attach to, when --attach is specified.
Operating modes:
--attach Attach to running process PID.
--multi Start server without a specific program, and
only quit when explicitly commanded.
--once Exit after the first connection has closed.
--help Print this message and then exit.
--version Display version information and exit.
Other options:
--wrapper WRAPPER -- Run WRAPPER to start new programs.
--disable-randomization
Run PROG with address space randomization disabled.
--no-disable-randomization
Don't disable address space randomization when
starting PROG.
Debug options:
--debug Enable general debugging output.
--debug-format=opt1[,opt2,...]
Specify extra content in debugging output.
Options:
all
none
timestamp
--remote-debug Enable remote protocol debugging output.
--disable-packet=opt1[,opt2,...]
Disable support for RSP packets or features.
Options:
vCont, Tthread, qC, qfThreadInfo and
threads (disable all threading packets).
For more information, consult the GDB manual (available as on-line
info or a printed manual).
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gdb/gdbserver/ChangeLog:
2015-04-01 Pedro Alves <palves@redhat.com>
Cleber Rosa <crosa@redhat.com>
* server.c (gdbserver_usage): Reorganize and extend the usage
message.
Alan Modra [Wed, 1 Apr 2015 08:49:27 +0000 (19:19 +1030)]
Start of relro segment adjustment
Adjusting the start of the relro segment in order to make it end
exactly on a page boundary runs into difficulties when sections in the
relro segment are aligned; Adjusting the start by (next_page - end)
sometimes results in more than that adjustment occurring at the end,
overrunning the page boundary. So when that occurs we try a new lower
start position by masking the adjusted start with the maximum section
alignment. However, we didn't consider that this masked start address
may in fact be before the initial relro base, which is silly since
that can only increase padding at the relro end.
I've also moved some calculations closer to where they are used, and
comments closer to the relevant statements.
* ldlang.c (lang_size_sections): When alignment of sections
results in relro base adjustment being too large, don't go lower
than the initial value.
* ldexp.c (fold_binary <DATA_SEGMENT_RELRO_END>): Comment.
* scripttempl/elf.sc (DATA_SEGMENT_ALIGN): Omit SEGMENT_SIZE
alignment when SEGMENT_SIZE is the same as MAXPAGESIZE.
Alan Modra [Wed, 1 Apr 2015 02:31:38 +0000 (13:01 +1030)]
Yet another warning fix
Older compilers that warn wrongly will just need -Wno-error. No way
am I going to init every single field, then have to edit this code
whenever bfd_link_hash_entry changes. Another option, making the
struct static, isn't very nice since it means larger binaries and
worse code.
Ed Schouten [Tue, 31 Mar 2015 14:47:10 +0000 (16:47 +0200)]
Fixes for a small number of compiler warnings
The ehdr_start_save variable does not need to be initialized. However,
not initializing it will trigger a compiler warning when using older
versions of GCC. Self-assignment unfortunately doesn't work for Clang
as Clang has a warning similar to -Winit-self as part of -Wall.
* emultempl/elf32.em (gld*_before_allocation): Zero-initialize
the ehdr_start_save variable.
Implement support for checking /proc/PID/coredump_filter
This patch, as the subject says, extends GDB so that it is able to use
the contents of the file /proc/PID/coredump_filter when generating a
corefile. This file contains a bit mask that is a representation of
the different types of memory mappings in the Linux kernel; the user
can choose to dump or not dump a certain type of memory mapping by
enabling/disabling the respective bit in the bit mask. Currently,
here is what is supported:
bit 0 Dump anonymous private mappings.
bit 1 Dump anonymous shared mappings.
bit 2 Dump file-backed private mappings.
bit 3 Dump file-backed shared mappings.
bit 4 (since Linux 2.6.24)
Dump ELF headers.
bit 5 (since Linux 2.6.28)
Dump private huge pages.
bit 6 (since Linux 2.6.28)
Dump shared huge pages.
(This table has been taken from core(5), but you can also read about it
on Documentation/filesystems/proc.txt inside the Linux kernel source
tree).
The default value for this file, used by the Linux kernel, is 0x33,
which means that bits 0, 1, 4 and 5 are enabled. This is also the
default for GDB implemented in this patch, FWIW.
Well, reading the file is obviously trivial. The hard part, mind you,
is how to determine the types of the memory mappings. For that, I
extended the code of gdb/linux-tdep.c:linux_find_memory_regions_full and
made it rely *much more* on the information gathered from
/proc/<PID>/smaps. This file contains a "verbose dump" of the
inferior's memory mappings, and we were not using as much information as
we could from it. If you want to read more about this file, take a look
at the proc(5) manpage (I will also write a blog post soon about
everything I had to learn to get this patch done, and when I it is ready
I will post it here).
With Oleg Nesterov's help, we could improve the current algorithm for
determining whether a memory mapping is anonymous/file-backed,
private/shared. GDB now also respects the MADV_DONTDUMP flag and does
not dump the memory mapping marked as so, and will always dump
"[vsyscall]" or "[vdso]" mappings (just like the Linux kernel).
In a nutshell, what the new code is doing is:
- If the mapping is associated to a file whose name ends with
" (deleted)", or if the file is "/dev/zero", or if it is "/SYSV%08x"
(shared memory), or if there is no file associated with it, or if
the AnonHugePages: or the Anonymous: fields in the /proc/PID/smaps
have contents, then GDB considers this mapping to be anonymous.
There is a special case in this, though: if the memory mapping is a
file-backed one, but *also* contains "Anonymous:" or
"AnonHugePages:" pages, then GDB considers this mapping to be *both*
anonymous and file-backed, just like the Linux kernel does. What
that means is simple: this mapping will be dumped if the user
requested anonymous mappings *or* if the user requested file-backed
mappings to be present in the corefile.
It is worth mentioning that, from all those checks described above,
the most fragile is the one to see if the file name ends with
" (deleted)". This does not necessarily mean that the mapping is
anonymous, because the deleted file associated with the mapping may
have been a hard link to another file, for example. The Linux
kernel checks to see if "i_nlink == 0", but GDB cannot easily do
this check (as it has been discussed, GDB would need to run as root,
and would need to check the contents of the /proc/PID/map_files/
directory in order to determine whether the deleted was a hardlink
or not). Therefore, we made a compromise here, and we assume that
if the file name ends with " (deleted)", then the mapping is indeed
anonymous. FWIW, this is something the Linux kernel could do
better: expose this information in a more direct way.
- If we see the flag "sh" in the VmFlags: field (in /proc/PID/smaps),
then certainly the memory mapping is shared (VM_SHARED). If we have
access to the VmFlags, and we don't see the "sh" there, then
certainly the mapping is private. However, older Linux kernels (see
the code for more details) do not have the VmFlags field; in that
case, we use another heuristic: if we see 'p' in the permission
flags, then we assume that the mapping is private, even though the
presence of the 's' flag there would mean VM_MAYSHARE, which means
the mapping could still be private. This should work OK enough,
however.
Finally, it is worth mentioning that I added a new command, 'set
use-coredump-filter on/off'. When it is 'on', it will read the
coredump_filter' file (if it exists) and use its value; otherwise, it
will use the default value mentioned above (0x33) to decide which memory
mappings to dump.
PR corefiles/16092
* linux-tdep.c: Include 'gdbcmd.h' and 'gdb_regex.h'.
New enum identifying the various options of the coredump_filter
file.
(struct smaps_vmflags): New struct.
(use_coredump_filter): New variable.
(decode_vmflags): New function.
(mapping_is_anonymous_p): Likewise.
(dump_mapping_p): Likewise.
(linux_find_memory_regions_full): New variables
'coredumpfilter_name', 'coredumpfilterdata', 'pid', 'filterflags'.
Removed variable 'modified'. Read /proc/<PID>/smaps file; improve
parsing of its information. Implement memory mapping filtering
based on its contents.
(show_use_coredump_filter): New function.
(_initialize_linux_tdep): New command 'set use-coredump-filter'.
* NEWS: Mention the possibility of using the
'/proc/PID/coredump_filter' file when generating a corefile.
Mention new command 'set use-coredump-filter'.
When loading a corefile that has some inaccessible memory region(s),
GDB complains about it:
(gdb) core /my/corefile
[New LWP 28468]
Cannot access memory at address 0x355fc21148
Cannot access memory at address 0x355fc21140
(gdb)
However, despite not seeing the message "Core was generated by...", it
is still possible to inspect the corefile using regular GDB commands.
The reason for that is because read_memory_unsigned_integer throws an
exception when it cannot read the memory region, but
solib_svr4_r_ldsomap was not catching it. The fix is to catch the
exception and act accordingly.
projects / thirdparty / binutils-gdb.git / log
