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344 commits

Author SHA1 Message Date
Simon Marchi
2b142a9f83 gdb/linux-nat: get core count using /sys/devices/system/cpu/possible
I get this test failure on my CI;

  FAIL: gdb.base/info-os.exp: get process list

The particularity of this setup is that builds are done in containers
who are allocated 4 CPUs on a machine that has 40.  The code in
nat/linux-osdata.c fails to properly fetch the core number for each
task.

linux_xfer_osdata_processes uses `sysconf (_SC_NPROCESSORS_ONLN)`, which
returns 4, so it allocates an array of 4 integers.  However, the core
numbers read from /proc/pid/task/tid/stat, by function
linux_common_core_of_thread, returns a value anywhere between 0 and 39.
The core numbers above 3 are therefore ignored, many processes end up
with no core value, and the regexp in the test doesn't match (it
requires an integer as the core field).

The way this the CPUs are exposed to the container is that the container
sees 40 CPUs "present" and "possible", but only 4 arbitrary CPUs
actually online:

    root@ci-node-jammy-amd64-04-08:~# cat /sys/devices/system/cpu/present
    0-39
    root@ci-node-jammy-amd64-04-08:~# cat /sys/devices/system/cpu/online
    5,11,24,31
    root@ci-node-jammy-amd64-04-08:~# cat /sys/devices/system/cpu/possible
    0-39

The solution proposed in this patch is to find out the number of
possible CPUs using /sys/devices/system/cpu/possible.  In practice, this
will probably always contain `0-N`, where N is the number of CPUs, minus
one.  But the documentation [1] doesn't such guarantee, so I'll assume
that it can contain a more complex range list such as `2,4-31,32-63`,
like the other files in that directory can have.  The solution is to
iterate over these numbers to find the highest possible CPU id, and
use that that value plus one as the size of the array to allocate.

[1] https://www.kernel.org/doc/Documentation/admin-guide/cputopology.rst

Change-Id: I7abce2e43b000c1327fa94cd7b99d46e49d7ccf3
2022-11-08 16:51:35 -05:00
Simon Marchi
7a283d9cf5 gdbsupport, gdb: add read_text_file_to_string, use it in linux_common_core_of_thread
I would like to add more code to nat/linux-osdata.c that reads an entire
file from /proc or /sys and processes it as a string afterwards.  I
would like to avoid duplicating the somewhat error-prone code that reads
an entire file to a buffer.  I think we should have a utility function
that does that.

Add read_file_to_string to gdbsupport/filestuff.{c,h}, and make
linux_common_core_of_thread use it.  I want to make the new function
return an std::string, and because strtok doesn't play well with
std::string (it requires a `char *`, std::string::c_str returns a `const
char *`), change linux_common_core_of_thread to use std::string methods
instead.

Approved-By: Tom Tromey <tom@tromey.com>
Change-Id: I1793fda72a82969c28b944a84acb953f74c9230a
2022-11-08 16:50:52 -05:00
Jon Turney
559a5ea452
Fix Cygwin build after bcb9251f
Absent _UNICODE being defined (which gdb's Makefile doesn't do),
windows.h will always define STARTUPINFO is as STARTUPINFOA, so this
cast isn't correct when create_process expects a STARTUPINFOW
parameter (i.e. in a Cygwin build).

Instead write this as &info_ex.StartupInfo (which is always of the
correct type).
2022-11-02 14:36:14 +00:00
Markus Metzger
d9757bcd43 gdb, btrace: fix family and model computation
In gdb/nat/linux-btrace.c:btrace_this_cpu() we initialize the cpu
structure given to the libipt btrace decoder.

We only consider the extended model field for family 0x6 and forget about
family 0xf and we don't consider the extended family field.  Fix it.
2022-10-28 07:42:53 +02:00
Pedro Alves
f34652de0b internal_error: remove need to pass __FILE__/__LINE__
Currently, every internal_error call must be passed __FILE__/__LINE__
explicitly, like:

  internal_error (__FILE__, __LINE__, "foo %d", var);

The need to pass in explicit __FILE__/__LINE__ is there probably
because the function predates widespread and portable variadic macros
availability.  We can use variadic macros nowadays, and in fact, we
already use them in several places, including the related
gdb_assert_not_reached.

So this patch renames the internal_error function to something else,
and then reimplements internal_error as a variadic macro that expands
__FILE__/__LINE__ itself.

The result is that we now should call internal_error like so:

  internal_error ("foo %d", var);

Likewise for internal_warning.

The patch adjusts all calls sites.  99% of the adjustments were done
with a perl/sed script.

The non-mechanical changes are in gdbsupport/errors.h,
gdbsupport/gdb_assert.h, and gdb/gdbarch.py.

Approved-By: Simon Marchi <simon.marchi@efficios.com>
Change-Id: Ia6f372c11550ca876829e8fd85048f4502bdcf06
2022-10-19 15:32:36 +01:00
Tom Tromey
02d04eac24 Use strwinerror in gdb/windows-nat.c
When working on windows-nat.c, it's useful to see an error message in
addition to the error number given by GetLastError.  This patch moves
strwinerror from gdbserver to gdbsupport, and then updates
windows-nat.c to use it.  A couple of minor changes to strwinerror
(constify the return type and use the ARRAY_SIZE macro) are also
included.
2022-08-16 08:04:37 -06:00
Enze Li
44ca285b73 gdb: initialize the data_head variable to eliminate compilation warnings
On a machine with gcc 12, I get this warning:

  CXX    nat/linux-btrace.o
In function ‘btrace_error linux_read_bts(btrace_data_bts*, btrace_target_info*, btrace_read_type)’,
    inlined from ‘btrace_error linux_read_btrace(btrace_data*, btrace_target_info*, btrace_read_type)’ at ../gdb/nat/linux-btrace.c:935:29:
../gdb/nat/linux-btrace.c:865:21: warning: ‘data_head’ may be used uninitialized [-Wmaybe-uninitialized]
  865 |   pevent->last_head = data_head;
      |   ~~~~~~~~~~~~~~~~~~^~~~~~~~~~~
../gdb/nat/linux-btrace.c: In function ‘btrace_error linux_read_btrace(btrace_data*, btrace_target_info*, btrace_read_type)’:
../gdb/nat/linux-btrace.c:792:9: note: ‘data_head’ was declared here
  792 |   __u64 data_head, data_tail;
      |         ^~~~~~~~~

Fix this by initializing the 'data_head' variable.

Tested by rebuilding on x86_64 openSUSE Tumbleweed with gcc 12.
2022-07-08 21:48:15 +08:00
Jon Turney
9dad432e10
Trivial fixes to Cygwin build after 8fea1a81
* Remove a stray semicolon
* Restore dropped nullptr program argument in use of create_process() under CYGWIN
2022-06-12 17:01:32 +01:00
Jon Turney
7d941aa3aa
Simplify cygwin_buf_t
Prior to c6ca3dab dropping support for Cygwin 1.5, cygwin_buf_t was
defined as char for Cygwin 1.5.  After that, it's always wchar_t, so
just use that.
2022-06-12 15:56:55 +01:00
Tom Tromey
20489cca90 Use subclasses of windows_process_info
This changes windows_process_info to use virtual methods for its
callbacks, and then changes the two clients of this code to subclass
this class to implement the methods.

I considered using CRTP here, but that would require making the new
structures visible to the compilation of of nat/windows-nat.c.  This
seemed like a bit of a pain, so I didn't do it.

This change then lets us change all the per-inferior globals to be
members of the new subclass.  Note that there can still only be a
single inferior -- currently there's a single global of the new type.
This is just another step toward possibly implementing multi-inferior
for Windows.

It's possible this could be cleaned up further... ideally I'd like to
move more of the data into the base class.  However, because gdb
supports Cygwin and gdbserver does not, and because I don't have a way
to build or test Cygwin, larger refactorings are difficult.
2022-06-07 11:44:53 -06:00
Tom Tromey
bcb9251f02 Allow ASLR to be disabled on Windows
On Windows, it is possible to disable ASLR when creating a process.
This patch adds code to do this, and hooks it up to gdb's existing
disable-randomization feature.  Because the Windows documentation
cautions that this isn't available on all versions of Windows, the
CreateProcess wrapper function is updated to make the attempt, and
then fall back to the current approach if it fails.
2022-06-07 09:59:41 -06:00
Tom Tromey
8fea1a81c7 Introduce wrapper for CreateProcess
This is a small refactoring that introduces a wrapper for the Windows
CreateProcess function.  This is done to make the next patch a bit
simpler.
2022-06-07 09:59:40 -06:00
Jon Turney
1f03fa9921
Fix Cygwin build after 0578e87f
Fix Cygwin build after 0578e87f ("Remove some globals from
nat/windows-nat.c").  Update code under ifdef __CYGWIN__ for globals
moved to members of struct windows_process_info.
2022-06-02 10:39:46 +01:00
Jon Turney
c9c157c765
Fix Cygwin build after fcab5839
Fix Cygwin build after fcab5839 ("Implement pid_to_exec_file for Windows
in gdbserver"). That change moves code from gdb/windows-nat.c to
gdb/nat/windows-nat.c, but doesn't add the required typedefs and
includes for parts of that code under ifdef __CYGWIN__.
2022-06-02 10:39:44 +01:00
Tom Tromey
fcab58390f Implement pid_to_exec_file for Windows in gdbserver
I noticed that gdbserver did not implement pid_to_exec_file for
Windows, while gdb did implement it.  This patch moves the code to
nat/windows-nat.c, so that it can be shared.  This makes the gdbserver
implementation trivial.
2022-05-13 08:21:16 -06:00
Tom Tromey
4eab18b566 Remove windows_process_info::id
I noticed that windows_process_info::id is only used by gdbserver, and
not really necessary.  This patch removes it.
2022-05-13 08:21:16 -06:00
Tom Tromey
0e90c44162 Constify target_pid_to_exec_file
This changes target_pid_to_exec_file and target_ops::pid_to_exec_file
to return a "const char *".  I couldn't build many of these targets,
but did examine the code by hand -- also, as this only affects the
return type, it's normally pretty safe.  This brings gdb and gdbserver
a bit closer, and allows for the removal of a const_cast as well.
2022-05-13 08:21:16 -06:00
Tom Tromey
0d1703b8fb Remove "typedef enum ..."
I noticed a few spots in GDB that use "typedef enum".  However, in C++
this isn't as useful, as the tag is automatically entered as a
typedef.  This patch removes most uses of "typedef enum" -- the
exceptions being in some nat-* code I can't compile, and
glibc_thread_db.h, which I think is more or less a copy of some C code
from elsewhere.

Tested by rebuilding.
2022-04-28 09:31:15 -06:00
Tom Tromey
bfdb52f83c Handle encoding failures in Windows thread names
Internally at AdaCore, we noticed that the new Windows thread name
code could fail.  First, it might return a zero-length string, but in
gdb conventions it should return nullptr instead.  Second, an encoding
failure could wind up showing replacement characters to the user; this
is confusing and not useful; it's better to recognize such errors and
simply discard the name.  This patch makes both of these changes.
2022-04-26 12:54:05 -06:00
Tom Tromey
8bbdbd6985 Use GetThreadDescription on Windows
Windows 10 introduced SetThreadDescription and GetThreadDescription, a
simpler way to set a thread's name.  This changes gdb and gdbserver to
use this convention when it is available.

This is part of PR win32/29050.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29050
2022-04-14 12:12:35 -06:00
Tom Tromey
44ac251ad2 Share handle_ms_vc_exception with gdbserver
Currently, gdb's native Windows target implements the exception-based
approach for setting thread names, but gdbserver does not.  This patch
moves handle_ms_vc_exception to the shared nat/windows-nat.c code, as
preparation for adding this support to gdbserver.
2022-04-14 12:12:34 -06:00
Tom Tromey
a69599e68b Fix possible Cygwin build problem
I noticed that nat/windows-nat.c checks __USEWIDE, but nothing sets it
there -- I forgot to copy over the definition when making this file.
This patch tries to fix the problem.  I don't have a Cygwin setup, so
I don't know whether this is sufficient, but it's probably necessary.
2022-04-14 12:12:34 -06:00
Tom Tromey
7ae6857316 Fix regression on Windows with WOW64
Internally at AdaCore, we recently started testing a 64-bit gdb
debugging 32-bit processes.  This failed with gdb head, but not with
gdb 11.

The tests fail like this:

     Starting program: [...].exe
     warning: Could not load shared library symbols for WOW64_IMAGE_SECTION.
     Do you need "set solib-search-path" or "set sysroot"?
     warning: Could not load shared library symbols for WOW64_IMAGE_SECTION.
     Do you need "set solib-search-path" or "set sysroot"?
     warning: Could not load shared library symbols for NOT_AN_IMAGE.
     Do you need "set solib-search-path" or "set sysroot"?
     warning: Could not load shared library symbols for NOT_AN_IMAGE.
     Do you need "set solib-search-path" or "set sysroot"?

After some debugging and bisecting, to my surprise the bug was
introduced by commit 183be222 ("gdb, gdbserver: make target_waitstatus
safe").

The problem occurs in handle_exception.  Previously the code did:

    -  ourstatus->kind = TARGET_WAITKIND_STOPPED;
    [...]
	 case EXCEPTION_BREAKPOINT:
    [...]
    -	  ourstatus->kind = TARGET_WAITKIND_SPURIOUS;
    [...]
	   /* FALLTHROUGH */
	 case STATUS_WX86_BREAKPOINT:
	   DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_BREAKPOINT");
    -      ourstatus->value.sig = GDB_SIGNAL_TRAP;
    [...]
    -  last_sig = ourstatus->value.sig;

However, in the new code, the fallthrough case does:

    +      ourstatus->set_stopped (GDB_SIGNAL_TRAP);

... which changes the 'kind' in 'ourstatus' after falling through.

This patch rearranges the 'last_sig' setting to more closely match
what was done before (this is probably not strictly needed but also
seemed harmless), and removes the fall-through in the
'ignore_first_breakpoint' case when __x86_64__ is defined.
2022-04-14 09:56:26 -06:00
Tom Tromey
0578e87f93 Remove some globals from nat/windows-nat.c
nat/windows-nat.c has a number of globals that it uses to communicate
with its clients (gdb and gdbserver).  However, if we ever want the
Windows ports to be multi-inferior, globals won't work.

This patch takes a step toward that by moving most nat/windows-nat.c
globals into a new struct windows_process_info.  Many functions are
converted to be methods on this object.

A couple of globals remain, as they are needed to truly be global due
to the way that the Windows debugging APIs work.

The clients still have a global for the current process.  That is,
this patch is a step toward the end goal, but doesn't implement the
goal itself.
2022-04-04 13:58:37 -06:00
Tom Tromey
fc0b013e44 Remove windows_thread_info destructor
windows_thread_info declares and defines a destructor, but this
doesn't need to be explicit.
2022-04-04 13:58:37 -06:00
John Baldwin
4bd817e71e nat: Split out platform-independent aarch64 debug register support.
Move non-Linux-specific support for hardware break/watchpoints from
nat/aarch64-linux-hw-point.c to nat/aarch64-hw-point.c.  Changes
beyond a simple split of the code are:

- aarch64_linux_region_ok_for_watchpoint and
  aarch64_linux_any_set_debug_regs_state renamed to drop linux_ as
  they are not platform specific.

- Platforms must implement the aarch64_notify_debug_reg_change
  function which is invoked from the platform-independent code when a
  debug register changes for a given debug register state.  This does
  not use the indirection of a 'low' structure as is done for x86.

- The handling for kernel_supports_any_contiguous_range is not
  pristine.  For non-Linux it is simply defined to true.  Some uses of
  this could perhaps be implemented as new 'low' routines for the
  various places that check it instead?

- Pass down ptid into aarch64_handle_breakpoint and
  aarch64_handle_watchpoint rather than using current_lwp_ptid which
  is only defined on Linux.  In addition, pass the ptid on to
  aarch64_notify_debug_reg_change instead of the unused state
  argument.
2022-03-22 12:05:43 -07:00
Simon Marchi
a288518611 gdb/linux: remove ptrace support check for exec, fork, vfork, vforkdone, clone, sysgood
I think it's safe to remove checking support for these ptrace features,
they have all been added in what is now ancient times (around the
beginning of Linux 2.6).  This allows removing a bit of complexity in
linux-nat.c and nat/linux-ptrace.c.

It also allows saving one extra fork every time we start debugging on
Linux: linux_check_ptrace_features forks a child process to test if some
ptrace features are supported.  That child process forks a grand-child,
to test whether ptrace reports an event for the fork by the child.  This
is no longer needed, if we assume the kernel supports reporting forks.

PTRACE_O_TRACEVFORKDONE was introduced in Linux in this change, in 2003:

  https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=45c1a159b85b3b30afd26a77b4be312226bba416

PTRACE_O_TRACESYSGOOD was supported at least as of this change, in 2002:

  https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=acc7088569c8eef04eeed0eff51d23bb5bcff964

PTRACE_O_TRACEFORK, PTRACE_O_TRACEVFORK, PTRACE_O_TRACEEXEC and
PTRACE_O_TRACECLONE were introduced in this change, in 2002:

  https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=a0691b116f6a4473f0fa264210ab9b95771a2b46

Change-Id: Iffb906549a89cc6b619427f976ec044706ab1e8d
2022-02-10 20:10:12 -05:00
Markus Metzger
cd393cec3a gdb, btrace: improve error messages
When trying to use 'record btrace' on a system that does not support it,
the error message isn't as clear as it could be.  See
https://sourceware.org/pipermail/gdb/2022-January/049870.html.

Improve the error message in a few cases.

Reported-by: Simon Sobisch  <simonsobisch@gnu.org>
2022-02-01 17:44:38 +01:00
Joel Brobecker
4a94e36819 Automatic Copyright Year update after running gdb/copyright.py
This commit brings all the changes made by running gdb/copyright.py
as per GDB's Start of New Year Procedure.

For the avoidance of doubt, all changes in this commits were
performed by the script.
2022-01-01 19:13:23 +04:00
Luis Machado
8a7cd1ebd7 [AArch64] Fix typo in error messages
Fix mispelling of PROT_ME to PROT_MTE in the error messages.
2021-12-21 15:05:52 -03:00
Tom de Vries
a92d031d7e [gdb/build] Fix x86_64 x32 build
A build error on x86_64 with x32 abi was reported here (
https://sourceware.org/pipermail/gdb/2021-November/049787.html ):
...
gdb/nat/amd64-linux-siginfo.c:280:42: error: \
  'struct compat_x32_siginfo_t::<unnamed union>::<unnamed>' has no member \
  named 'si_addr_bnd'
280 | #define cpt_si_lower _sifields._sigfault.si_addr_bnd._lower
| ^~~~~~~~~~~
gdb/nat/amd64-linux-siginfo.c:337:38: note: in expansion of macro 'cpt_si_lower'
337 | to->cpt_si_lower = from_ptrace.cpt_si_lower;
| ^~~~~~~~~~~~
...

The problem is that code added in commit d3d7d1ba3b "[gdb/tdep] Handle
si_addr_bnd in compat_siginfo_from_siginfo" doesn't compile on an x86_64 x32
setup, because compat_x32_siginfo_t doesn't have the si_addr_bnd fields.

Fix this conservatively by disabling the code for x32.

Tested on x86_64-linux.
2021-11-22 12:21:46 +01:00
Sergei Trofimovich
486f9e20e0 gdb/nat/linux-osdata.c: fix build on gcc-12 (string overfow)
On gcc-12 build fails as:

    ../../gdbserver/../gdb/nat/linux-osdata.c: In function 'void linux_xfer_osdata_processes(buffer*)':
    ../../gdbserver/../gdb/nat/linux-osdata.c:330:39: error:
      '__builtin___sprintf_chk' may write a terminating nul past the end of the destination [-Werror=format-overflow=]
      330 |                 sprintf (core_str, "%d", i);
          |                                       ^

It's an off-by-one case in an infeasible scenario for negative
huge core count. The change switches to std::string for memory
handling.

Tested by running 'info os processes' and checking CPU cores column.
2021-11-17 08:13:18 +00:00
Tom Tromey
0b03c6f03d Fix build on rhES5
The rhES5 build failed due to an upstream import a while back.  The
bug here is that, while the 'personality' function exists,
ADDR_NO_RANDOMIZE is only defined in <linux/personality.h>, not
<sys/personality.h>.

However, <linux/personality.h> does not declare the 'personality'
function, and <sys/personality.h> and <linux/personality.h> cannot
both be included.

This patch restores one of the removed configure checks and updates
the code to check it.

We had this as a local patch at AdaCore, because it seemed like there
was no interest upstream.  However, now it turns out that this fixes
PR build/28555, so I'm sending it now.
2021-11-09 08:21:18 -07:00
Simon Marchi
183be22290 gdb, gdbserver: make target_waitstatus safe
I stumbled on a bug caused by the fact that a code path read
target_waitstatus::value::sig (expecting it to contain a gdb_signal
value) while target_waitstatus::kind was TARGET_WAITKIND_FORKED.  This
meant that the active union field was in fact
target_waitstatus::value::related_pid, and contained a ptid.  The read
signal value was therefore garbage, and that caused GDB to crash soon
after.  Or, since that GDB was built with ubsan, this nice error
message:

    /home/simark/src/binutils-gdb/gdb/linux-nat.c:1271:12: runtime error: load of value 2686365, which is not a valid value for type 'gdb_signal'

Despite being a large-ish change, I think it would be nice to make
target_waitstatus safe against that kind of bug.  As already done
elsewhere (e.g. dynamic_prop), validate that the type of value read from
the union matches what is supposed to be the active field.

 - Make the kind and value of target_waitstatus private.
 - Make the kind initialized to TARGET_WAITKIND_IGNORE on
   target_waitstatus construction.  This is what most users appear to do
   explicitly.
 - Add setters, one for each kind.  Each setter takes as a parameter the
   data associated to that kind, if any.  This makes it impossible to
   forget to attach the associated data.
 - Add getters, one for each associated data type.  Each getter
   validates that the data type fetched by the user matches the wait
   status kind.
 - Change "integer" to "exit_status", "related_pid" to "child_ptid",
   just because that's more precise terminology.
 - Fix all users.

That last point is semi-mechanical.  There are a lot of obvious changes,
but some less obvious ones.  For example, it's not possible to set the
kind at some point and the associated data later, as some users did.
But in any case, the intent of the code should not change in this patch.

This was tested on x86-64 Linux (unix, native-gdbserver and
native-extended-gdbserver boards).  It was built-tested on x86-64
FreeBSD, NetBSD, MinGW and macOS.  The rest of the changes to native
files was done as a best effort.  If I forgot any place to update in
these files, it should be easy to fix (unless the change happens to
reveal an actual bug).

Change-Id: I0ae967df1ff6e28de78abbe3ac9b4b2ff4ad03b7
2021-10-21 16:13:56 -04:00
Andrew Pinski
add3db9182 Fix ARMv8.4 for hw watchpoint and breakpoint
Just like my previoius patch for ARMv8.1 and v8.2 (49ecef2a7d),
this adds ARMv8.4 debug arch as being compatible for hw watchpoint
and breakpoints.
2021-10-21 19:02:02 +00:00
Andrew Pinski
f81ce492b2 Refactor code slightly in nat/aarch64-linux-hw-point.c (aarch64_linux_get_debug_reg_capacity)
Since the two locations which check the debug arch are the same code currently, it is
a good idea to factor it out to a new function and just use that function from
aarch64_linux_get_debug_reg_capacity. This is also the first step to support
ARMv8.4 debug arch.
2021-10-21 19:02:01 +00:00
Simon Marchi
13084383e8 gdbsupport: make gdb_open_cloexec return scoped_fd
Make gdb_open_cloexec return a scoped_fd, to encourage using automatic
management of the file descriptor closing.  Except in the most trivial
cases, I changed the callers to just release the fd, which retains their
existing behavior.  That will allow the transition to using scoped_fd
more to go gradually, one caller at a time.

Change-Id: Ife022b403f96e71d5ebb4f1056ef6251b30fe554
2021-09-30 15:21:48 -04:00
Tom Tromey
184ea2f731 Remove defaulted 'tid' parameter to ptid_t constructor
I wanted to find, and potentially modify, all the spots where the
'tid' parameter to the ptid_t constructor was used.  So, I temporarily
removed this parameter and then rebuilt.

In order to make it simpler to search through the "real" (nonzero)
uses of this parameter, something I knew I'd have to do multiple
times, I removed any ", 0" from constructor calls.

Co-Authored-By: John Baldwin <jhb@FreeBSD.org>
2021-09-23 09:30:54 -06:00
Tom Tromey
7a2813c00b Use CORE_ADDR as return type from x86_dr_low_get_addr
On a Windows build locally, watchpoints started failing.  I tracked
this down to x86_dr_low_get_addr returning an 'unsigned long'... in
this particular build, this is a 32-bit type, but the inferior is a
64-bit program.

This patch fixes the problem by changing the return type.  No other
change is required, because this matches the function pointer in
struct x86_dr_low_type.
2021-09-03 11:30:46 -06:00
Simon Marchi
11bd012ed2 gdb: make inferior::m_cwd an std::string
Same idea as the previous patch, but for m_cwd.

To keep things consistent across the board, change get_inferior_cwd as
well, which is shared with GDBserver.  So update the related GDBserver
code too.

Change-Id: Ia2c047fda738d45f3d18bc999eb67ceb8400ce4e
2021-07-23 15:38:54 -04:00
Simon Marchi
85460c161d gdb: convert nat/x86-dregs.c macros to functions
I'm debugging why GDB crashes on OpenBSD/amd64, turns out it's because
x86_dr_low.get_status is nullptr.  It would have been useful to be able
to break on x86_dr_low_get_status, so I thought it would be a good
reason to convert these function-like macros into functions.

Change-Id: Ic200b50ef8455b4697bc518da0fa2bb704cf4721
2021-07-17 22:45:40 -04:00
Pedro Alves
c57eb1a269 nat/amd64-linux-siginfo.c: Remove typedefs
Since GDB is written in C++ now, we don't need struct/union typedefs
any more.  Remove them from nat/amd64-linux-siginfo.c.

gdb/ChangeLog:
yyyy-mm-dd  Pedro Alves  <pedro@palves.net>

	* nat/amd64-linux-siginfo.c (union nat_sigval): Rename to ...
	(nat_sigval_t): ... this and remove typedef of same name.
	(struct nat_siginfo): Rename to ...
	(nat_siginfo_t): ... this and remove typedef of same name.
	(struct compat_sigval): Rename to ...
	(compat_sigval_t): ... this and remove typedef of same name.
	(struct compat_siginfo): Rename to ...
	(compat_siginfo_t): ... this and remove typedef of same name.
	(struct compat_x32_siginfo): Rename to ...
	(compat_x32_siginfo_t): ... this and remove typedef of same name.
	(amd64_linux_siginfo_fixup_common): Adjust.
2021-06-07 23:22:39 +01:00
Pedro Alves
d8ca8e9fac nat/amd64-linux-siginfo.c: Move align attribute from typedef to struct
Compiling GDB with current git Clang (future 13) fails with (among
other problems), this issue:

 $ make nat/amd64-linux-siginfo.o
   CXX    nat/amd64-linux-siginfo.o
 src/gdb/nat/amd64-linux-siginfo.c:590:35: warning: passing 4-byte aligned argument to 8-byte aligned parameter 1 of 'compat_x32_siginfo_from_siginfo' may result in an unaligned pointer access [-Walign-mismatch]
	 compat_x32_siginfo_from_siginfo ((struct compat_x32_siginfo *) inf,
					  ^
 1 warning generated.

The problem is that:

  - The flagged code is casting to "struct compat_x32_siginfo" pointer
    directly instead of to a pointer to the compat_x32_siginfo_t
    typedef.  The called function is declared with a
    compat_x32_siginfo_t typedef pointer parameter.

  - Only the typedef has the __aligned__ attribute.

Fix this by moving the attribute to the struct, so both struct and
typedef have the same alignment.

The next patch removes the typedefs.

gdb/ChangeLog:
yyyy-mm-dd  Pedro Alves  <pedro@palves.net>

	* nat/amd64-linux-siginfo.c (compat_x32_siginfo_t): Move
	__attribute__ __aligned__ from the typedef to the struct.
2021-06-07 23:22:07 +01:00
Simon Marchi
24b21115f5 gdb: fix tab after space indentation issues
I spotted some indentation issues where we had some spaces followed by
tabs at beginning of line, that I wanted to fix.  So while at it, I did
a quick grep to find and fix all I could find.

gdb/ChangeLog:

	* Fix tab after space indentation issues throughout.

Change-Id: I1acb414dd9c593b474ae2b8667496584df4316fd
2021-05-27 15:18:49 -04:00
Simon Marchi
01add95bed gdb: fix some indentation issues
I wrote a small script to spot a pattern of indentation mistakes I saw
happened in breakpoint.c.  And while at it I ran it on all files and
fixed what I found.  No behavior changes intended, just indentation and
addition / removal of curly braces.

gdb/ChangeLog:

	* Fix some indentation mistakes throughout.

gdbserver/ChangeLog:

	* Fix some indentation mistakes throughout.

Change-Id: Ia01990c26c38e83a243d8f33da1d494f16315c6e
2021-05-27 15:01:28 -04:00
Tom Tromey
5917321695 Fix ubsan build
I tried a build using the undefined behavior sanitizer, and gcc gave
this error:

In file included from /usr/include/string.h:495,
                 from ../gnulib/import/string.h:41,
                 from ../../binutils-gdb/gdb/../gdbsupport/common-defs.h:95,
                 from ../../binutils-gdb/gdb/nat/linux-osdata.c:20:
In function 'char* strncpy(char*, const char*, size_t)',
    inlined from 'void time_from_time_t(char*, int, TIME_T)' at ../../binutils-gdb/gdb/nat/linux-osdata.c:923:15,
    inlined from 'void time_from_time_t(char*, int, TIME_T)' at ../../binutils-gdb/gdb/nat/linux-osdata.c:911:1,
    inlined from 'void linux_xfer_osdata_sem(buffer*)' at ../../binutils-gdb/gdb/nat/linux-osdata.c:1082:22:
/usr/include/bits/string_fortified.h:106:34: error: 'char* __builtin_strncpy(char*, const char*, long unsigned int)' specified bound 32 equals destination size [-Werror=stringop-truncation]

This patch fixes the problem by subtracting one from the length
parameter to strncpy.

I changed a couple of other similar functions -- gcc does not warn
about these, but I didn't see any substantial difference between the
different cases, and I think these are just latent warnings, to be
triggered in the future by a change to inlining heuristics.

gdb/ChangeLog
2021-05-17  Tom Tromey  <tromey@adacore.com>

	* nat/linux-osdata.c (user_from_uid, time_from_time_t)
	(group_from_gid): Subtract one from strncpy length.
2021-05-17 13:06:05 -06:00
Simon Marchi
31aceaef1c gdb, gdbserver: make status_to_str display the signal name
I was looking at some "set debug lin-lwp" logs, and saw that a thread
received the "Child exited" signal.  It took me a moment to realize that
this was SIGCHLD.  I then thought that it would be nice for
status_to_str to show the signal name (SIGCHLD) in addition to the
description "Child exited", since people are much more used to referring
to signals using their names.

Fortunately, libiberty contains a handy function to get the signal name
from the signal number, strsigno, use that.

The output of "set debug lin-lwp" now looks like:

    [linux-nat] linux_nat_wait_1: waitpid 1209631 received SIGTRAP - Trace/breakpoint trap (stopped)

gdb/ChangeLog:

	* nat/linux-waitpid.c (status_to_str): Show signal name.

Change-Id: I8ad9b1e744dd64461fd87b08d5c29f9ef97c4691
2021-05-10 12:13:36 -04:00
Simon Marchi
8d06918ff5 gdb, gdbserver: make status_to_str return std::string
Instead of using a static buffer.  This is safer, and we don't really
mind about any extra dynamic allocation here, since it's only used for
debug purposes.

gdb/ChangeLog:

	* nat/linux-waitpid.c (status_to_str): Return std::string.
	* nat/linux-waitpid.h (status_to_str): Likewise.
	* linux-nat.c (linux_nat_post_attach_wait): Adjust.
	(linux_nat_target::attach): Adjust.
	(linux_handle_extended_wait): Adjust.
	(wait_lwp): Adjust.
	(stop_wait_callback): Adjust.
	(linux_nat_filter_event): Adjust.
	(linux_nat_wait_1): Adjust.
	* nat/linux-waitpid.c (status_to_str): Adjust.
	* nat/linux-waitpid.h (status_to_str): Adjust.

gdbserver/ChangeLog:

	* linux-low.cc (linux_process_target::wait_for_event_filtered):
	Adjust to status_to_str returning std::string.

Change-Id: Ia8aead70270438a5690f243e6faafff6c38ff757
2021-05-08 21:07:20 -04:00
Pedro Alves
4655f8509f Don't run personality syscall at configure time; don't check it at all
Currently, in order to tell whether support for disabling address
space randomization on Linux is available, GDB checks if the
personality syscall works, at configure time.  I.e., it does a run
test, instead of a compile/link test:

  AC_RUN_IFELSE([PERSONALITY_TEST],
		[have_personality=true],
		[have_personality=false],

This is a bit bogus, because the machine the build is done on may not
(and is when you consider distro gdbs) be the machine that eventually
runs gdb.  It would be better if this were a compile/link test
instead, and then at runtime, GDB coped with the personality syscall
failing.  Actually, GDB already copes.

One environment where this is problematic is building GDB in a Docker
container -- by default, Docker runs the container with seccomp, with
a profile that disables the personality syscall.  You can tell Docker
to use a less restricted seccomp profile, but I think we should just
fix it in GDB.

"man 2 personality" says:

       This system call first appeared in Linux 1.1.20 (and thus first
       in a stable kernel release with Linux 1.2.0); library support
       was added in glibc 2.3.

...

       ADDR_NO_RANDOMIZE (since Linux 2.6.12)
              With this flag set, disable address-space-layout randomization.

glibc 2.3 was released in 2002.
Linux 2.6.12 was released in 2005.

The original patch that added the configure checks was submitted in
2008.  The first version of the patch that was submitted to the list
called personality from common code:

 https://sourceware.org/pipermail/gdb-patches/2008-June/058204.html

and then was moved to Linux-specific code:

 https://sourceware.org/pipermail/gdb-patches/2008-June/058209.html

Since HAVE_PERSONALITY is only checked in Linux code, and
ADDR_NO_RANDOMIZE exists for over 15 years, I propose just completely
removing the configure checks.

If for some odd reason, some remotely modern system still needs a
configure check, then we can revert this commit but drop the
AC_RUN_IFELSE in favor of always doing the AC_LINK_IFELSE
cross-compile fallback.

gdb/ChangeLog:

	* linux-nat.c (linux_nat_target::supports_disable_randomization):
	Remove references to HAVE_PERSONALITY.
	* nat/linux-personality.c: Remove references to HAVE_PERSONALITY.
	(maybe_disable_address_space_randomization)
	(~maybe_disable_address_space_randomizatio): Remove references to
	HAVE_PERSONALITY.
	* config.in, configure: Regenerate.

gdbserver/ChangeLog:

	* linux-low.cc:
	(linux_process_target::supports_disable_randomization): Remove
	reference to HAVE_PERSONALITY.
	* config.in, configure: Regenerate.

gdbsupport/ChangeLog:

	* common.m4 (personality test): Remove.
2021-05-08 13:45:36 +01:00
Tom Tromey
1bee48c7ad Make get_image_name static
The only callers of get_image_name are nat/windows-nat.c, so make it
static.

gdb/ChangeLog
2021-04-30  Tom Tromey  <tromey@adacore.com>

	* nat/windows-nat.h (get_image_name): Don't declare.
	* nat/windows-nat.c (get_image_name): Now static.
2021-04-30 10:22:24 -06:00