Joel Brobecker [Thu, 10 May 2018 15:27:13 +0000 (10:27 -0500)]
gdbserver/Windows: crash during connection establishment phase
On Windows, starting a new process with GDBserver seems to work,
in the sense that the program does get started, and GDBserver
confirms that it is listening for GDB to connect. However, as soon as
GDB establishes the connection with GDBserver, and starts discussing
with it, GDBserver crashes, with a SEGV.
This SEGV occurs in remote-utils.c::prepare_resume_reply...
| regp = current_target_desc ()->expedite_regs;
| [...]
| while (*regp)
... because, in our case, REGP is NULL.
This patches fixes the issues by adding a parameter to init_target_desc,
in order to make sure that we always provide the list of registers when
we initialize a target description.
gdb/ChangeLog:
PR server/23158:
* regformats/regdat.sh: Adjust script, following the addition
of the new expedite_regs parameter to init_target_desc.
gdb/gdbserver/ChangeLog:
PR server/23158:
* tdesc.h (init_target_desc) <expedite_regs>: New parameter.
* tdesc.c (init_target_desc) <expedite_regs>: New parameter.
Use it to set the expedite_regs field in the given tdesc.
* x86-tdesc.h: New file.
* linux-aarch64-tdesc.c (aarch64_linux_read_description):
Adjust following the addition of the new expedite_regs parameter
to init_target_desc.
* linux-tic6x-low.c (tic6x_read_description): Likewise.
* linux-x86-tdesc.c: #include "x86-tdesc.h".
(i386_linux_read_description, amd64_linux_read_description):
Adjust following the addition of the new expedite_regs parameter
to init_target_desc.
* lynx-i386-low.c: #include "x86-tdesc.h".
(lynx_i386_arch_setup): Adjust following the addition of the new
expedite_regs parameter to init_target_desc.
* nto-x86-low.c: #include "x86-tdesc.h".
(nto_x86_arch_setup): Adjust following the addition of the new
expedite_regs parameter to init_target_desc.
* win32-i386-low.c: #include "x86-tdesc.h".
(i386_arch_setup): Adjust following the addition of the new
expedite_regs parameter to init_target_desc.
if (!was_running && !multi_mode)
error ("No program to debug");
What happens is that the "last_status" global starts initialized
as zeroes, which means last_status.kind == TARGET_WAITKIND_EXITED,
and we expect create_inferior to be waiting for the inferior to
start until reaching the SIGTRAP, and to set the "last_status"
global to match that last event we received.
I suspect this is an unintended side-effect of the following change...
... which removes some code in server.c that was responsible for
starting the inferior in a functin that was named start_inferior,
and looked like this:
signal_pid = create_inferior (new_argv[0], &new_argv[0]);
[...]
/* Wait till we are at 1st instruction in program, return new pid
(assuming success). */
last_ptid = mywait (pid_to_ptid (signal_pid), &last_status, 0, 0);
The code has been transitioned to using fork_inferior, but sadly,
only for the targets that support it. On Windows, the calls to wait
setting "last_status" simply disappeared.
This patch adds it back in the Windows-specific implementation of
create_inferior.
Joel Brobecker [Thu, 10 May 2018 15:23:10 +0000 (10:23 -0500)]
[gdbserver/win32] fatal "glob could not process pattern '(null)'" error
Trying to start GDBserver on Windows currently yields the following
error...
$ gdbserver.exe --once :4444 simple_main.exe
glob could not process pattern '(null)'.
Exiting
... after which GDB terminates with a nonzero status.
This is because create_process in win32-low.c calls gdb_tilde_expand
with the result of a call to get_inferior_cwd without verifying that
the returned directory is not NULL:
Omair Javaid [Tue, 1 May 2018 01:31:32 +0000 (06:31 +0500)]
Fix tagged pointer support
This patch fixes tagged pointer support for AArch64 GDB. Linux kernel
debugging failure was reported after tagged pointer support was committed.
After a discussion around best path forward to manage tagged pointers
on GDB side we are going to disable tagged pointers support for
aarch64-none-elf-gdb because for non-linux applications we cant be
sure if tagged pointers will be used by MMU or not.
Also for aarch64-linux-gdb we are going to sign extend user-space
address after clearing tag bits. This will help debug both kernel
and user-space addresses based on information from linux kernel
documentation given below:
According to AArch64 memory map:
https://www.kernel.org/doc/Documentation/arm64/memory.txt
"User addresses have bits 63:48 set to 0 while the kernel addresses have
the same bits set to 1."
According to AArch64 tagged pointers document:
https://www.kernel.org/doc/Documentation/arm64/tagged-pointers.txt
The kernel configures the translation tables so that translations made
via TTBR0 (i.e. userspace mappings) have the top byte (bits 63:56) of
the virtual address ignored by the translation hardware. This frees up
this byte for application use.
Running gdb testsuite after applying this patch introduces no regressions
and tagged pointer test cases still pass.
Jan Kratochvil [Thu, 12 Apr 2018 20:31:39 +0000 (22:31 +0200)]
Fix -D_GLIBCXX_DEBUG gdb-add-index regression
Fedora Rawhide started to use -D_GLIBCXX_DEBUG which made gdb-add-index
failing:
gdb: Out-of-bounds vector access while running gdb-add-index
https://bugzilla.redhat.com/show_bug.cgi?id=1540559
/usr/include/c++/7/debug/safe_iterator.h:270:
Error: attempt to dereference a past-the-end iterator.
Objects involved in the operation:
iterator "this" @ 0x0x7fffffffcb90 {
type = __gnu_debug::_Safe_iterator<__gnu_cxx::__normal_iterator<unsigned char*, std::__cxx1998::vector<unsigned char, gdb::default_init_allocator<unsigned char, std::allocator<unsigned char> > > >, std::__debug::vector<unsigned char, gdb::default_init_allocator<unsigned char, std::allocator<unsigned char> > > > (mutable iterator);
state = past-the-end;
references sequence with type 'std::__debug::vector<unsigned char, gdb::default_init_allocator<unsigned char, std::allocator<unsigned char> > >' @ 0x0x7fffffffcc50
}
/usr/include/c++/7/debug/vector:417:
Error: attempt to subscript container with out-of-bounds index 556, but
container only holds 556 elements.
Objects involved in the operation:
sequence "this" @ 0x0x2e87af8 {
type = std::__debug::vector<partial_symbol*, std::allocator<partial_symbol*> >;
}
The two -D_GLIBCXX_DEBUG regressions were made by:
commit bc8f2430e08cc2a520db49a42686e0529be4a3bc
Author: Jan Kratochvil <jan.kratochvil@redhat.com>
Date: Mon Jun 12 16:29:53 2017 +0100
Code cleanup: C++ify .gdb_index producer
commit af5bf4ada48ff65b6658be1fab8f9c8f8ab5f319
Author: Simon Marchi <simon.marchi@ericsson.com>
Date: Sat Oct 14 08:06:29 2017 -0400
Replace psymbol_allocation_list with std::vector
gdb/ChangeLog
2018-04-12 Jan Kratochvil <jan.kratochvil@redhat.com>
H.J. Lu [Wed, 4 Apr 2018 11:36:44 +0000 (04:36 -0700)]
i386: Clear vex instead of vex.evex
"vex" has many fields to control how to decode an instruction. Clear
all fields in "vex" before decoding an instruction to avoid using values
left from the previous instruction.
gas/
PR gdb/23028
PR binutils/23025
* testsuite/gas/i386/prefix.s: Add tests for vcvtpd2dq with
VEX and EVEX prefixes.
* testsuite/gas/i386/prefix.d: Updated.
opcodes/
PR gdb/23028
PR binutils/23025
* i386-dis.c (get_valid_dis386): Don't set vex.prefix nor vex.w
to 0.
(print_insn): Clear vex instead of vex.evex.
Introduced a regression when compiling for mingw*:
/gdb/common/pathstuff.c: In function 'gdb::unique_xmalloc_ptr<char>
gdb_realpath(const char*)':
/gdb/common/pathstuff.c:56:14: error: 'MAX_PATH' was not declared in this scope
char buf[MAX_PATH];
^
/gdb/common/pathstuff.c:57:5: error: 'DWORD' was not declared in this scope
DWORD len = GetFullPathName (filename, MAX_PATH, buf, NULL);
^
/gdb/common/pathstuff.c:57:11: error: expected ';' before 'len'
DWORD len = GetFullPathName (filename, MAX_PATH, buf, NULL);
^
/gdb/common/pathstuff.c:63:9: error: 'len' was not declared in this scope
if (len > 0 && len < MAX_PATH)
^
/gdb/common/pathstuff.c:64:54: error: 'buf' was not declared in this scope
return gdb::unique_xmalloc_ptr<char> (xstrdup (buf));
^
make[2]: *** [pathstuff.o] Error 1
The proper fix is to conditionally include "<windows.h>". This commit
does that, without introducing any regressions as per tests made by
our BuildBot.
Change order of error message printed when gdbserver can't find CWD
I forgot to address Pedro's comment about my last patch and change the
order of the message printed when getcwd returns NULL on gdbserver.
This obvious commit does it.
Simon mentioned on IRC that, after the startup-with-shell feature has
been implemented on gdbserver, it is not possible to specify a
filename-only binary, like:
$ gdbserver :1234 a.out
/bin/bash: line 0: exec: a.out: not found
During startup program exited with code 127.
Exiting
This happens on systems where the current directory "." is not listed
in the PATH environment variable. Although including "." in the PATH
variable is a possible workaround, this can be considered a regression
because before startup-with-shell it was possible to use only the
filename (due to reason that gdbserver used "exec*" directly).
The idea of the patch is to verify if the program path provided by the
user (or by the remote protocol) contains a directory separator
character. If it doesn't, it means we're dealing with a filename-only
binary, so we call "gdb_abspath" to properly expand it and transform
it into a full path. Otherwise, we leave the program path untouched.
This mimicks the behaviour seen on GDB (look at "openp" and
"attach_inferior", for example).
I am also submitting a testcase which exercises the scenario described
above. This test requires gdbserver to be executed in a different CWD
than the original, so I also created a helper function, "with_cwd" (on
testsuite/lib/gdb.exp), which takes care of cd'ing into and out of the
specified dir.
Built and regtested on BuildBot, without regressions.
gdb/ChangeLog:
2018-02-28 Sergio Durigan Junior <sergiodj@redhat.com>
Simon Marchi <simon.marchi@polymtl.ca>
* common/common-utils.c: Include "sys/stat.h".
(is_regular_file): Move here from "source.c"; change return
type to "bool".
* common/common-utils.h (is_regular_file): New prototype.
* common/pathstuff.c (contains_dir_separator): New function.
* common/pathstuff.h (contains_dir_separator): New prototype.
* source.c: Don't include "sys/stat.h".
(is_regular_file): Move to "common/common-utils.c".
* server.c: Include "filenames.h" and "pathstuff.h".
(program_name): Delete variable.
(program_path): New anonymous class.
(get_exec_wrapper): Use "program_path" instead of
"program_name".
(handle_v_run): Likewise.
(captured_main): Likewise.
(process_serial_event): Likewise.
This commit moves the path manipulation routines found on utils.c to a
new common/pathstuff.c, and updates the Makefile.in's accordingly.
The routines moved are "gdb_realpath", "gdb_realpath_keepfile" and
"gdb_abspath".
This will be needed because gdbserver will have to call "gdb_abspath"
on my next patch, which implements a way to expand the path of the
inferior provided by the user in order to allow specifying just the
binary name when starting gdbserver, like:
$ gdbserver :1234 a.out
With the recent addition of the startup-with-shell feature on
gdbserver, this scenario doesn't work anymore if the user doesn't have
the current directory listed in the PATH variable.
I had to do a minor adjustment on "gdb_abspath" because we don't have
access to "tilde_expand" on gdbserver, so now the function is using
"gdb_tilde_expand" instead. Otherwise, the code is the same.
Regression tested on the BuildBot, without regressions.
projects / thirdparty / binutils-gdb.git / log
