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Although the manual has a comment saying these are superceded by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).
Report bugs to "<http://www.gnu.org/software/gdb/bugs/>".
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
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.
Antoine Tremblay [Wed, 25 Mar 2015 15:49:05 +0000 (11:49 -0400)]
Add cpu information to the info os command on linux.
This patch adds cpu information on linux based on /proc/cpuinfo as :
cpus Listing of all cpus/cores on the system
This patch also reorders the info os commands so that they are listed
in alphabetical order.
gdb/ChangeLog:
* NEWS: Mention info os cpus support.
* gdb/nat/linux-osdata.c (linux_xfer_osdata_cpus): New function.
(struct osdata_type): Add cpus entry, reorder the entries in
alphabetical order.
gdb/doc/ChangeLog:
* gdb.texinfo (Operating System Auxiliary Information): Add info os cpus
documentation, reorder the info os entries in alphabetical order.
With newer versions of gcc (5.x), the extern inline we're using with the
cgen-{mem,ops} modules no longer work. Since this code really wants the
gnu inline semantics, use that attribute explicitly.
Jing Yu [Mon, 30 Mar 2015 21:06:12 +0000 (14:06 -0700)]
Support AARCH64_TLSLD_ADD_DTPREL_* relocations.
Also Change _TLS_MODULE_BASE_. Always let it point to the start
of TLS segment.
2015-03-28 Jing Yu <jingyu@google.com>
* aarch64-reloc.def: New TLSLD_ADD_DTPREL_HI12,
TLSLD_ADD_DTPREL_LO12_NC.
* aarch64.cc (Target_aarch64::define_tls_base_symbol): Always
let _TLS_MODULE_BASE_ point to the start of tls segment.
(Target_aarch64::optimize_tls_reloc): Add cases for
R_AARCH64_TLSLD_ADD_DTPREL_HI12 and
R_AARCH64_TLSLD_ADD_DTPREL_LO12_NC.
(Target_aarch64::Scan::local): Likewise.
(Target_aarch64::Scan::global): Likewise.
(Target_aarch64::Relocate::relocate): Likewise.
(Target_aarch64::Relocate::relocate_tls): Likewise. And remove
subtracting tls segment size from symbol value for
TLSLD_*_DTPREL relocations.
Mike Frysinger [Mon, 30 Mar 2015 07:05:57 +0000 (03:05 -0400)]
sim: arm: convert to nrun
A lot of cpu state is stored in global variables, as is memory handling.
The sim_size support needs unwinding at some point. But at least this
is an improvement on the status quo.
Mike Frysinger [Mon, 30 Mar 2015 06:27:22 +0000 (02:27 -0400)]
sim: arm: use common configure options
In preparation for converting to nrun, call the common functions that
are needed. This doesn't produce any new warnings, and the generated
code should be the same.
Gary Benson [Mon, 30 Mar 2015 13:58:33 +0000 (14:58 +0100)]
Remove three redundant wrapper functions in remote.c
gdb/ChangeLog:
* remote.c (remote_mourn_1): Remove function. Update all callers
to use remote_mourn.
(extended_remote_mourn_1): Remove function. Update all callers
to use extended_remote_mourn.
(extended_remote_attach_1): Remove function. Update all callers
to use extended_remote_attach.
H.J. Lu [Mon, 30 Mar 2015 11:40:33 +0000 (04:40 -0700)]
Properly set sh_info for .rela.plt/rel.plt section
Since .rela.plt/rel.plt section may contain relocations against .got.plt
section, we set sh_info for .rela.plt/rel.plt section to .got.plt section
index if target has .got.plt section.
bfd/
PR ld/18169
* elf-bfd.h (elf_backend_data): Add get_reloc_section.
(_bfd_elf_get_reloc_section): New.
* elf.c (_bfd_elf_get_reloc_section): Likewise.
(assign_section_numbers): Call get_reloc_section to look up the
section the relocs apply.
* elfxx-target.h (elf_backend_get_reloc_section): Likewise.
(elfNN_bed): Initialize get_reloc_section with
elf_backend_get_reloc_section.
Mike Frysinger [Mon, 30 Mar 2015 06:05:33 +0000 (02:05 -0400)]
sim: d10v: convert to nrun
A lot of cpu state is stored in global variables, as is memory handling.
The sim_size support needs unwinding at some point. But at least this
is an improvement on the status quo.
Mike Frysinger [Mon, 30 Mar 2015 05:14:04 +0000 (01:14 -0400)]
sim: d10v: use common configure options
In preparation for converting to nrun, call the common functions that
are needed. This doesn't produce any new warnings, and the generated
code should be the same.
Mike Frysinger [Mon, 30 Mar 2015 04:13:38 +0000 (00:13 -0400)]
sim: cr16: convert to nrun
A lot of cpu state is stored in global variables, as is memory handling.
The sim_size support needs unwinding at some point. But at least this
is an improvement on the status quo.
Mike Frysinger [Mon, 30 Mar 2015 02:42:33 +0000 (22:42 -0400)]
sim: cr16: use common configure options
In preparation for converting to nrun, call the common functions that
are needed. This doesn't produce any new warnings, and the generated
code should be the same.
Mike Frysinger [Sun, 29 Mar 2015 21:40:30 +0000 (17:40 -0400)]
sim: microblaze: convert to nrun
This port already was storing its cpu state in the sim_cpu structure, so
converting it over was pretty easy. It is allocating memory itself still,
but we'll fix that up in the future at some point.
Mike Frysinger [Sun, 29 Mar 2015 21:20:37 +0000 (17:20 -0400)]
sim: mcore/microblaze: delete dead code
The mcore port had a few structs/defines that were never used.
Similarly, the microblaze port, because it was copied from mcore, has
that same dead code, and more. The watchpoint logic was never actually
used. Punt it all.
Mike Frysinger [Sun, 29 Mar 2015 20:41:59 +0000 (16:41 -0400)]
sim; testsuite: allow tests to set no output
If a test doesn't write anything at all to stdout, the current test
framework can't support that. Even if you put a blank output line:
# output:
the setup happily clobbers that with a default pass/fail string.
Tweak the parsing logic so we only set the output to pass/fail when
the test has no output marker.
With newer versions of gcc (5.x), the extern inline we're using with the
sim-arange module no longer works. Since this code really wants the gnu
inline semantics, use that attribute explicitly.
Reported-by: DJ Delorie <dj@redhat.com> Reported-by: Joel Sherrill <joel.sherrill@oarcorp.com>
Mike Frysinger [Sun, 29 Mar 2015 15:48:46 +0000 (11:48 -0400)]
sim: testsuite: make subdir unconditional
Since the testsuite subdir has to handle dynamic arch values already,
there's no real value in requiring arches to opt in to it. Most have
a testsuite now anyways, and we're requiring it in the future.
Mike Frysinger [Sun, 29 Mar 2015 08:18:03 +0000 (04:18 -0400)]
sim: microblaze: use common configure options
In preparation for converting to nrun, call the common functions that
are needed. This doesn't produce any new warnings, and the generated
code should be the same.
Mike Frysinger [Sun, 29 Mar 2015 07:53:01 +0000 (03:53 -0400)]
sim: mcore: convert to nrun
A lot of cpu state is stored in global variables, as is memory handling.
The sim_size support needs unwinding at some point. But at least this
is an improvement on the status quo.
Mike Frysinger [Sun, 29 Mar 2015 07:39:01 +0000 (03:39 -0400)]
sim: mcore: use common configure options
In preparation for converting to nrun, call the common functions that
are needed. This doesn't produce any new warnings, and the generated
code should be the same.
Mike Frysinger [Sun, 29 Mar 2015 07:29:29 +0000 (03:29 -0400)]
sim: mcore: drop sbrk support
The sbrk syscall assumes the sbrk region starts after the bss and the
current implementation requires a bss section to exist. Since there
is no requirement for programs to have a bss in general, we want to
drop this check. However, there is still the sbrk syscall that wants
to know about the region.
Since libgloss doesn't actually use the sbrk syscall (it implements
sbrk in its own way), and the sim really shouldn't enforce a specific
memory layout on programs, lets simply delete sbrk support. Now it
always returns an error.
Mike Frysinger [Sat, 28 Mar 2015 21:36:03 +0000 (17:36 -0400)]
sim: sh: convert to nrun
A lot of cpu state is stored in global variables, as is memory handling.
The sim_size support needs unwinding at some point. But at least this
is an improvement on the status quo.
Mike Frysinger [Sat, 28 Mar 2015 18:09:11 +0000 (14:09 -0400)]
sim: sh: clean up gencode
The build line was missing the normal BUILD_xxx flags. Once we added
that, we get warnings that weren't shown before. As we fix those, we
notice that the -d option segfaults because it tries to write readonly
memory. Fix that too as part of the const/prototype clean up.
I think this patch is wrong. Starting with that commit (f30d5c7),
some tests (e.g. mi-break.exp) started to fail for me, because
of gdb segfaulting.
The address of expr is passed to the cleanup. When the cleanup is ran,
expr is no longer in scope, so what is at that address is probably not
safe to use anymore. That's my guess.
gdb/ChangeLog
2015-03-27 Jan Kratochvil <jan.kratochvil@redhat.com>
Joel Brobecker [Fri, 27 Mar 2015 13:37:34 +0000 (06:37 -0700)]
Initialize EXPR in dtrace-probe::dtrace_process_dof_probe
GCC 4.4.7 generates the following warning:
| cc1: warnings being treated as errors
| dtrace-probe.c: In function ‘dtrace_process_dof_probe’:
| dtrace-probe.c:416: error: ‘expr’ may be used uninitialized in this function
| make[2]: *** [dtrace-probe.o] Error 1
Later versions (GCC 5) do a better job and don't generate the warning,
but it does not hurt to pre-initialize "expr" to NULL.
gdb/ChangeLog:
* dtrace-probe.c (dtrace_process_dof_probe): Initialize expr to NULL.
Indexes returned for special sections are off by one, i.e. with N+4
sections last one has index N+4 returned which is outside allocated
obstack (at the same time index N is not used at all).
In worst case, if sections obstack is allocated up to end of chunk,
writing last section data will cause buffer overrun and some data
corruption.
Here's output from Valgrind::
==14630== Invalid write of size 8
==14630== at 0x551B1A: add_to_objfile_sections_full (objfiles.c:225)
==14630== by 0x552768: allocate_objfile (objfiles.c:324)
==14630== by 0x4E8E2E: symbol_file_add_with_addrs (symfile.c:1171)
==14630== by 0x4E9453: symbol_file_add_from_bfd (symfile.c:1280)
==14630== by 0x4E9453: symbol_file_add (symfile.c:1295)
==14630== by 0x4E94B7: symbol_file_add_main_1 (symfile.c:1320)
==14630== by 0x514246: catch_command_errors_const (main.c:398)
==14630== by 0x5150AA: captured_main (main.c:1061)
==14630== by 0x51123C: catch_errors (exceptions.c:240)
==14630== by 0x51569A: gdb_main (main.c:1164)
==14630== by 0x408824: main (gdb.c:32)
==14630== Address 0x635f3b8 is 8 bytes after a block of size 4,064 alloc'd
==14630== at 0x4C2ABA0: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==14630== by 0x60F797: xmalloc (common-utils.c:41)
==14630== by 0x5E787FB: _obstack_begin (obstack.c:184)
==14630== by 0x552679: allocate_objfile (objfiles.c:294)
==14630== by 0x4E8E2E: symbol_file_add_with_addrs (symfile.c:1171)
==14630== by 0x4E9453: symbol_file_add_from_bfd (symfile.c:1280)
==14630== by 0x4E9453: symbol_file_add (symfile.c:1295)
==14630== by 0x4E94B7: symbol_file_add_main_1 (symfile.c:1320)
==14630== by 0x514246: catch_command_errors_const (main.c:398)
==14630== by 0x5150AA: captured_main (main.c:1061)
==14630== by 0x51123C: catch_errors (exceptions.c:240)
==14630== by 0x51569A: gdb_main (main.c:1164)
==14630== by 0x408824: main (gdb.c:32)
gdb/ChangeLog:
* gdb_bfd.c (gdb_bfd_section_index): Fix off-by-one for special
sections.