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When building GDB on Cygwin, gdb/gdb.exe is a libtool wrapper (which
happens to be a PE executable). The real executable is at
gdb/.libs/gdb.exe. The "does gdb have debug info test" that
_selftest_setup does is bogus, because it loads the libtool wrapper
(which doesn't have debug info), doesn't see any debug info, and thus
the test is skipped.
The "correct" way to deal with libtool wrappers is to run the shell
command you want to run under `libtool --mode=execute`. That will
replace any path resembling to a libtool wrapper with the real
executable path. But it will also add to the environment the library
paths necessary for this executable to find the libraries it needs.
Therefore, modify the `do_self_tests` proc to:
- run the top-level GDB commands under `libtool --mode=execute`
- pass the path to the inferior GDB on the command-line of the
top-level, so that it gets replaced with the real executable's path
However, the "file" command was previously used to detect the presence
of debug info in the GDB executable. It's not easy to implement this
check when loading the executable directly on the command line. So, add
a separate proc, _selftest_check_executable_debug_info, that spawns a
temporary GDB and does the debug info check through the file command.
This proc uses libtool to obtain the path to the real executable.
When building, we use the bundled libtool.m4 at the top of the tree.
This means that the libtool system package, and therefore the libtool
binary, might not be available. Check for the presence of the libtool
binary first, and only do the conversion if it is found. If it is not
found, the test should still work on platforms that don't require the
conversion.
With this commit, the test runs on Cygwin, even though there are
failures later.
Change-Id: Ie7b712cdc84671a5a017655a7e41687ff23f906c
Reviewed-By: Keith Seitz <keiths@redhat.com>
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In the ROCm-GDB testing process, we hit a problem that is a combination
of these 3 factors:
1. In the downstream ROCm-GDB packages, the gdb executable is built with
a relative RUNPATH:
0x000000000000001d (RUNPATH) Library runpath: [${ORIGIN}/../lib]
This is done so that the installation is relocatable (the whole ROCm
directory can be copied around) and things still work. For instance,
the rocgdb executable needs to be able to find the libraries it
needs, such as `librocm-dbgapi.so.0`. The relative runpath allows
that.
2. For testing, we run the testsuite against the gdb executable
installed from one of those packages. It is possible to ./configure
the testsuite directory on its own, and then do:
$ make check RUNTESTFLAGS="GDB=/opt/rocm/bin/rocgdb"
3. The selftests (such as gdb.gdb/selftest.exp) copy the GDB under test
to the standard output directory, before trying to debug it.
The problem is that the gdb executable under test that has been copied
can't find the libraries it needs.
With this patch, I propose that we don't copy the gdb executable, but
debug it in place instead. The comment removed in this patch says "in
case this OS doesn't like to edit its own text space", and has been
there since forever in some form. But it's not clear if there is a host
OS (where we intend to run this test) that needs this nowadays. I would
bet that there isn't. If there is in fact a GDB host OS (where we
intend to run this test) that needs it, we can reinstate the copying,
but as an opt-in operation.
Another situation where this change helps is on Windows, where
gdb/gdb.exe is a libtool wrapper (the real executable is at
gdb/.libs/gdb.exe). Copying gdb/gdb.exe doesn't accomplish anything
useful. The next patch does further changes to account for the libtool
wrapper case.
I tested on Linux and Cygwin, more testing would be welcome.
Change-Id: Id4148517d4fc4ecdd49f099c12003e3d16c6a93d
Reviewed-By: Keith Seitz <keiths@redhat.com>
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The function to stop at is always main. Remove the parameter and
hard-code main in _selftest_setup.
Change-Id: Ibbbf598203b1658305eb6bc631d029652c10edac
Reviewed-By: Keith Seitz <keiths@redhat.com>
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Rename some procs in lib/selftest-support.exp that are only used
internally, to make it a bit clearer that they are just internal
helpers.
Change-Id: Icd399ac42698209fbc8e798bf43a7d8464aa848c
Reviewed-By: Keith Seitz <keiths@redhat.com>
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pre-commit pointed out that gdbarch_components.py had a minor
formatting issue, according to the official version of 'black'. This
patch corrects the oversight.
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There is a bug in expect, see:
https://sourceforge.net/p/expect/patches/26/
which causes empty substring matches from a regexp to instead return
the complete input buffer. To reproduce this bug, try this command:
expect -c 'spawn sh -c "echo -n -e \"abc\""; \
expect -re "(a?)(a)(bc)"; \
puts "\n"; \
for { set i 1 } { $i < 4 } { incr i } { \
puts -nonewline "($i): \""; \
puts -nonewline $expect_out($i,string); \
puts "\"" \
}'
For a working expect the output looks like:
spawn sh -c echo -n -e "abc"
abc
(1): ""
(2): "a"
(3): "bc"
But for a broken expect the output looks like:
spawn sh -c echo -n -e "abc"
abc
(1): "abc"
(2): "a"
(3): "bc"
Notice that (1) is now returning the complete input buffer rather than
the empty string, this is wrong.
This is not the first time this bug has impacted GDB's testsuite,
this commit seems to be working around the same problem:
commit e579b537353cd91cb8fac1eaeb69901d4936766f
Date: Sat Aug 16 20:32:37 2025 +0200
[gdb/testsuite] Fix TUI tests on freebsd
I recently pushed this commit:
commit 3825c972a636852600b47c242826313f4b9963b8
Date: Wed Jun 18 15:02:29 2025 +0100
gdb: allow gdb.Color to work correctly with pagination
Which added gdb.python/py-color-pagination.exp. Bug PR gdb/33321 was
then created as the test was failing on some hosts. Turns out, this
is same expect bug.
The fix presented here is the same as for e579b537353cd91cb8, avoid
using optional regexp substrings at the start of a regexp, and instead
use two separate regexp patterns. With this change in place, the test
now passes on all hosts.
There's no change in what is being tested after this commit.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=33321
Approved-By: Tom de Vries <tdevries@suse.de>
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On msys2-ucrt64, with test-case gdb.server/non-existing-program.exp I get:
...
(gdb) quit^M
gdb_caching_proc allow_xml_test caused gdb_exit to be called
gdb_caching_proc allow_xml_test marked as called
gdb_caching_proc get_mount_point_map marked as called
builtin_spawn gdbserver stdio non-existing-program^M
Error creating process "non-existing-program " (error 2): \
The system cannot find the file specified.^M^M
Exiting^M^M
FAIL: gdb.server/non-existing-program.exp: gdbserver exits cleanly
...
This happens because this regexp fails to match:
...
# This is what we get on Windows.
-re "Error creating process\r\n\r\nExiting\r\n" {
...
Fix this by updating the regexp.
Tested on x86_64-w64-mingw32 (msys2-ucrt64).
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Say we disable startup-with-shell, we get:
...
(gdb) run `echo 8`^M
Starting program: a2-run `echo 8`^M
[Thread debugging using libthread_db enabled]^M
Using host libthread_db library "/lib64/libthread_db.so.1".^M
usage: factorial <number>^M
[Inferior 1 (process 10787) exited with code 01]^M
(gdb) FAIL: gdb.base/a2-run.exp: run "a2-run" with shell (timeout)
...
Fix this by only doing this test if startup-with-shell is supported.
This fixes the test-case on msys2-ucrt64, where startup-with-shell is not
supported.
Likewise in other test-cases.
Tested on x86_64-linux.
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I ran test-case gdb.python/py-color-pagination.exp with make-check-all.sh and
noticed failures when using remote host.
So I grepped to find all test-cases using with_ansi_styling_terminal and ran
them with host/target board local-remote-host-native.
Fix the failing test-cases using require {!is_remote host}.
Tested on x86_64-linux.
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Update gdbpy_create_ptid_object (python/py-infthread.c) to return a
gdbpy_ref<> rather than a 'PyObject *'. This reduces the chances that
a caller will leak an object, though no such memory leaks are fixed in
this commit, this is just a code improvement patch.
There should be no user visible changes after this commit.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
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In corelow.c, in the function rename_vmcore_idle_reg_sections, the
argument ABFD holds the core file bfd pointer. When this function is
called current_program_space->core_bfd() is passed as the argument
value.
Within this function, we sometimes use the function argument, and
sometimes access current_program_space->core_bfd() directly.
This is confusing, and unnecessary. Lets not do that.
I've renamed the argument to cbfd (for Core file BFD), and then
updated the function to make use of this argument throughout. This
reduces the number of accesses to global state, which is, I think, a
good thing.
There should be no user visible changes after this commit.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
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This commit changes the signature of the gdbarch_core_info_proc method
so that it takes a 'struct bfd *' as an extra argument. This argument
is used to pass through the core file bfd pointer.
Now, in corelow.c, when calling gdbarch_core_info_proc, we can pass
through current_program_space->core_bfd() as the argument. Within the
implementations, (Linux and FreeBSD) we can use this argument rather
than having to access the core file through current_program_space.
This reduces the use of global state, which I think is a good thing.
There should be no user visible changes after this commit.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
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The function linux_read_core_file_mappings is passed an argument CBFD,
which is the BFD for the core file. In
core_target::build_file_mappings, where the function is called, we
pass current_program_space->core_bfd() as the argument.
However, in linux_read_core_file_mappings, in some places we use the
CBFD argument, and in other places we directly use
current_program_space->core_bfd(). This is confusing, and
unnecessary. Lets not do that.
Standardise on just using CBFD. This removes some references to
global state in favour of passing the global state in as an argument,
I think this is a good thing.
There should be no user visible changes after this commit.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
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Implement support for XOP instructions [1] in amd64_get_insn_details.
The encoding scheme is documented here [2]. Essentially it's a variant of the
VEX3 encoding scheme, with:
- 0x8f as the first byte instead of 0xc4, and
- an opcode map >= 8.
The changes are roughly the same as the XOP part of an earlier submission [3],
hence the tag.
The only real difference is that that patch proposed to implement xop_prefix_p
using:
...
return pfx[0] == 0x8f && (pfx[1] & 0x38);
...
which tries to resolve the conflict between the XOP prefix (starts with 0x8f)
and the POP instruction (opcode 0x8f) by detecting that it's not a POP
instruction.
Instead, use the way AMD has resolved this conflict in the specification, by
checking for opcode map >= 8:
...
gdb_byte m = pfx[1] & 0x1f;
return pfx[0] == 0x8f && m >= 8;
...
Tested on x86_64-linux.
Co-Authored-By: Jan Beulich <jbeulich@suse.com>
Reviewed-By: Klaus Gerlicher<klaus.gerlicher.@intel.com>
[1] https://en.wikipedia.org/wiki/XOP_instruction_set
[2] https://www.amd.com/content/dam/amd/en/documents/archived-tech-docs/programmer-references/43479.pdf
[3] https://sourceware.org/pipermail/gdb-patches/2019-February/155347.html
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I noticed a possible memory leak in gdbpy_create_ptid_object, in
py-infthread.c. We create a Tuple, and hold the reference in a
'PyObject*' local.
If we then fail to create any of the tuple contents we perform an
early exit, returning nullptr, this will leak the Tuple object.
Currently, we create the Tuple as the first action in the function,
but we don't really need the tuple until the end of the function.
In this commit I have:
1. Moved creation of the Tuple until the end of the function, just
before we need it.
2. Stored the Tuple reference in a gdbpy_ref<>. This is not
strictly needed any more, but is (I think) good practice as
future changes to the function will not need to worry about
releasing the Tuple object.
3. Taken the opportunity to replace a NULL with nullptr in this
function.
4. Inlined the local variable declarations to the point of first
use.
There should be no user visible changes after this commit.
No tests as I have no idea how to make gdb_py_object_from_longest (and
friends) fail, and so trigger the memory leak. I suspect we'd never
actually see this leak in the real world, but it doesn't hurt to clean
these things up.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
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(1) Description of Problem:
When debugging the following code, the execution result of
the backtrace command is incorrect.
$ cat test.S
.text
.globl fun1
.type fun1, @function
fun1:
or $r12,$r0,$r0
or $r4,$r12,$r0
jr $r1
.globl fun
.type fun, @function
fun:
addi.d $r3,$r3,-16
st.d $r1,$r3,8
bl fun1
or $r12,$r4,$r0
or $r4,$r12,$r0
ld.d $r1,$r3,8
addi.d $r3,$r3,16
jr $r1
.globl main
.type main, @function
main:
addi.d $r3,$r3,-16
st.d $r1,$r3,8
bl fun
nop
ld.d $r1,$r3,8
addi.d $r3,$r3,16
jr $r1
$ gcc test.S -o test
$ gdb test
...
(gdb) b fun1
Breakpoint 1 at 0x748
(gdb) r
Breakpoint 1, 0x0000555555554748 in fun1 ()
(gdb) bt
#0 0x0000555555554748 in fun1 ()
#1 0x0000555555554758 in fun ()
#2 0x0000555555554758 in fun ()
#3 0x0000555555554758 in fun ()
....
--Type <RET> for more, q to quit, c to continue without paging
(2) Root Cause Analysis:
The return address of fun() in r1(ra) is saved on the stack:
addi.d $r3,$r3,-16
st.d $r1,$r3,8
The bl instruction in fun () will call the fun1 () and save
the value of pc+4 to r1(ra).
bl fun1
or $r12,$r4,$r0
Because registers such as fp and ra saved in the stack of the sub-function
are not recorded in current code. When trace back fun() to main(), the pc
of the previous frame to be read from ra register instead of the saved location
on the stack. At this time, the value of ra register in fun() is already the
address of the next instruction after the bl. So it is impossible to trace
back to the main().
(3) Solution:
Record the location of ra, fp, s0 to s8 on the stack to ensure the correct
execution of backtrace.
(4) Test:
$ gdb test
...
(gdb) b fun1
Breakpoint 1 at 0x748
(gdb) r
Breakpoint 1, 0x0000555555554748 in fun1 ()
(gdb) bt
#0 0x0000555555554748 in fun1 ()
#1 0x0000555555554758 in fun ()
#2 0x0000555555554778 in main ()
Signed-off-by: Hui Li <lihui@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
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(1) Description of Problem:
When debugging the following code, the execution result of
nexti command is incorrect.
$ cat test.S
.text
.globl fun
.type fun, @function
fun:
or $r12,$r0,$r0
or $r4,$r12,$r0
jr $r1
.globl main
.type main, @function
main:
addi.d $r3,$r3,-16
st.d $r1,$r3,8
bl fun
or $r12,$r4,$r0
or $r4,$r12,$r0
ld.d $r1,$r3,8
addi.d $r3,$r3,16
jr $r1
$ gcc test.S -o test
$ gdb test
...
(gdb) set disassemble-next-line on
(gdb) start
...
Temporary breakpoint 1, 0x0000555555554754 in main ()
=> 0x0000555555554754 <main+8>: 57ffefff bl -20 # 0x555555554740 <fun>
(gdb) ni
0x0000555555554740 in fun ()
=> 0x0000555555554740 <fun+0>: 0015000c move $t0, $zero
(2) Root Cause Analysis:
In the internal execution flow of the ni command, a single-step will be
executed first. After that, it will enter process_event_stop_test (),
some conditions are judged in this function.
if ((get_stack_frame_id (frame)
!= ecs->event_thread->control.step_stack_frame_id)
&& get_frame_type (frame) != SIGTRAMP_FRAME
&& ((frame_unwind_caller_id (frame)
== ecs->event_thread->control.step_stack_frame_id)
&& ((ecs->event_thread->control.step_stack_frame_id
!= outer_frame_id)
|| (ecs->event_thread->control.step_start_function
!= find_pc_function (ecs->event_thread->stop_pc ())))))
{
...
if (ecs->event_thread->control.step_over_calls == STEP_OVER_ALL)
...
else
insert_step_resume_breakpoint_at_caller (frame);
}
Here, it will be judged whether a sub-function has been called based on
whether the frame id before the single step is not equal to the current
frame id and whether there is a calling relationship.
If a sub-function is called at this time and the current operation is nexti,
it will not stop immediately. Instead, insert_step_resume_breakpoint_at_caller()
will be called to complete the execution of the sub-function and then stop.
In above debugging examples, the executable program being debugged is compiled
from an asm source file that does not contain dwarf information. Therefore, the
frame id of the function is calculated by loongarch_frame_unwind rather than
dwarf2_frame_unwind. However, loongarch_scan_prologue() has not yet recorded
stack information in loongarch_frame_cache, this will cause problems in some
operations related to the frame id information.
(3) Solution:
Improve loongarch_scan_prologue() to record the stack information in
loongarch_frame_cache. And improve the loongarch_frame_unwind_stop_reason()
through the information recorded in loongarch_frame_cache.
(4) Test:
After this patch:
$ gdb test
(gdb) set disassemble-next-line on
(gdb) start
Temporary breakpoint 1, 0x0000555555554754 in main ()
=> 0x0000555555554754 <main+8>: 57ffefff bl -20 # 0x555555554740 <fun>
(gdb) ni
0x0000555555554758 in main ()
=> 0x0000555555554758 <main+12>: 0015008c move $t0, $a0
(gdb) ni
0x000055555555475c in main ()
=> 0x000055555555475c <main+16>: 00150184 move $a0, $t0
Signed-off-by: Hui Li <lihui@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
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In the current code, loongarch_frame_unwind is a LoongArch prologue unwinder,
it contains the required member functions, but they do not calculate a valid
frame id through prologue of a function frame. Refactor these functions and
use loongarch_frame_cache to record the information of the function frame.
No functional change intended.
Signed-off-by: Hui Li <lihui@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
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Add the definition of loongarch_frame_cache for loongarch_frame_unwind,
this is preparation for later patch on LoongArch.
Signed-off-by: Hui Li <lihui@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
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VEX and EVEX-encoded instructions generally require a ModR/M byte, with the
notable exception of vzeroall and vzeroupper (opcode 0x77), which do not
use ModR/M.
This change sets need_modrm = 1 for VEX instructions, and adds an exception
for instructions where *insn == 0x77, following Intel’s SDM.
EVEX has no exceptions and thus always sets need_modrm to 1.
Additionally, the legacy twobyte_has_modrm table cannot be used for VEX and
EVEX instructions, as these encodings have different requirements and
exceptions. The logic is now explicit for VEX/EVEX handling.
Add vpblendw to selftest amd64_insn_decode.
The Intel SDM says the following:
1. Intel® 64 and IA-32 Architectures Software Developer’s Manual
Section 2.2.1.2 — Instruction Prefixes
"The VEX prefix is a multi-byte prefix that replaces several legacy prefixes
and opcode bytes. The VEX prefix is not an opcode; it is a prefix that
modifies the instruction that follows."
Section 2.2.1.3 — Opcode Bytes
"The opcode byte(s) follow any instruction prefixes (including VEX). The
opcode specifies the operation to be performed."
Section 2.2.2 — Instruction Format
"If a VEX prefix is present, it is processed as a single prefix, and the
opcode bytes follow immediately after the VEX prefix."
Source: Intel® SDM Vol. 2A, Section 2.2.1.2 and 2.2.2 (See Vol. 2A,
PDF pages 2-4, 2-5, and 2-7)
2. ModRM Byte Requirement
Intel® SDM Vol. 2A, Table 2-2 — VEX Prefix Encoding
"Most VEX-encoded instructions require a ModRM byte, except for a few
instructions such as VZEROALL and VZEROUPPER."
Source: Intel® SDM Vol. 2A, Table 2-2 (See Vol. 2A, PDF page 2-13)
Approved-By: Tom de Vries <tdevries@suse.de>
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On x86_64-freebsd, I ran into trouble with test-case
gdb.dwarf2/macro-source-path-clang14-dw4.exp (and similar), and I managed to
reproduce the problem on x86_64-linux by making dwarf2_support return 0.
The failure looks like:
...
UNSUPPORTED: $exp: require failed: dwarf2_support
UNRESOLVED: $exp: testcase aborted due to invalid command name: do_test
ERROR: tcl error sourcing $exp.
...
I fixed a similar problem in commit 3e488d8ccd0 ("[gdb/testsuite] Fix
gdb.dwarf2/dw-form-strx-out-of-bounds.exp with make-check-all.sh").
Fix this by moving "require dwarf2_support" from
gdb.dwarf2/macro-source-path.exp.tcl to the files including it.
Tested on x86_64-linux.
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On s390x, a big-endian machine, I'm seeing these test failures:
FAIL: gdb.base/dump.exp: array as memory, tekhex; file restored ok
FAIL: gdb.base/dump.exp: array as memory, tekhex; value restored ok
FAIL: gdb.base/dump.exp: array as value, tekhex; file restored ok
FAIL: gdb.base/dump.exp: array as value, tekhex; value restored ok
FAIL: gdb.base/dump.exp: array copy, tekhex; file restored ok
FAIL: gdb.base/dump.exp: array copy, tekhex; value restored ok
FAIL: gdb.base/dump.exp: array partial, tekhex; file restored ok
FAIL: gdb.base/dump.exp: array partial, tekhex; value restored ok
FAIL: gdb.base/dump.exp: dump array as memory, tekhex
FAIL: gdb.base/dump.exp: dump array as value, tekhex
FAIL: gdb.base/dump.exp: dump struct as memory, tekhex
FAIL: gdb.base/dump.exp: dump struct as value, tekhex
FAIL: gdb.base/dump.exp: reload array as memory, tekhex; value restored ok
FAIL: gdb.base/dump.exp: reload array as value, tekhex; value restored ok
FAIL: gdb.base/dump.exp: reload struct as memory, tekhex; value restored ok
FAIL: gdb.base/dump.exp: reload struct as value, tekhex; value restored ok
FAIL: gdb.base/dump.exp: struct as memory, tekhex; file restored ok
FAIL: gdb.base/dump.exp: struct as memory, tekhex; value restored ok
FAIL: gdb.base/dump.exp: struct as value, tekhex; file restored ok
FAIL: gdb.base/dump.exp: struct as value, tekhex; value restored ok
FAIL: gdb.base/dump.exp: struct copy, tekhex; file restored ok
FAIL: gdb.base/dump.exp: struct copy, tekhex; value restored ok
It turns out that there's a subtle bug in move_section_contents in
bfd/tekhex.c. The bug is that when attempting to write a buffer that
starts with a zero byte, the function will return false, an error
condition, without writing anything. But it also doesn't set
bfd_error, so GDB ends up displaying whatever the last unrelated error
was, e.g.:
warning: writing dump file '.../intstr1.tekhex' (No such file or directory)
When I investigated this, the bfd error was set during failure to
open a separate debug file for the test case, which is totally
unrelated to this problem.
The reason this fails on big endian machines is that the test case
writes out structs and arrays of int initialized to small values. On
little endian machines, the small integer is the first byte, so the
error doesn't occur. On big endian machines, a zero byte occurs
first, triggering the error.
On the GDB side of things, I've made a one line change to the test
case to cause the error to also happen on little endian machines. I
simply shift value of the first field in the struct left by 16 bits.
That leaves at least one zero byte on both sides of the non-zero part
of the int. I shifted it by 16 because, for a moment, there was a
question in my mind about what would happen with a second zero byte,
but it turns out that it's not a problem.
On the bfd side of things, take a look at move_section_contents() and
find_chunk() in tekhex.c. The scenario is this: we enter
move_section_contents with locationp pointing at a character buffer
whose first byte is zero. The 'get' parameter is false, i.e. we're
writing, not reading. The other critical fact is that the
abfd->tdata.tekhex_data->data is NULL (0).
I'm going to go through the execution path pretty much line by line
with commentary below the line(s) just executed.
char *location = (char *) locationp;
bfd_vma prev_number = 1; /* Nothing can have this as a high bit. */
I can't say that the comment provides the best explanation about
what's happening, but the gist is this: later on, chunk_number will
have it's low bits masked away, therefore no matter what it is, it
can't possibly be equal to prev_number when it's set to 1.
struct data_struct *d = NULL;
BFD_ASSERT (offset == 0);
for (addr = section->vma; count != 0; count--, addr++)
{
Set d to NULL and enter the loop.
/* Get high bits of address. */
bfd_vma chunk_number = addr & ~(bfd_vma) CHUNK_MASK;
bfd_vma low_bits = addr & CHUNK_MASK;
Use CHUNK_MASK, which is 0x1fff, to obtain the chunk number, i.e.
whatever's left after masking off the low 13 bits of addr, and
low_bits, which are the low 13 bits of addr. chunk_number matters for
understanding this bug, low_bits does not. Remember that no matter
what addr is, once you mask off the low 13 bits, it can't be equal to 1.
bool must_write = !get && *location != 0;
!get is true, *location != 0 is false, therefore the conjunction is
false, and furthermore must_write is false. I.e. even though we are
writing, we don't transfer zero bytes to the chunk - this is why
must_write is false. (The reason this works is that a chunk, once
allocated, is zero'd as part of the allocation using bfd_zalloc.
Therefore we can skip transferring zero bytes and, if enough of them
are skipped one after another, chunk allocation simply doesn't happen.
That's a good thing.)
if (chunk_number != prev_number || (!d && must_write))
For the reason provided above, chunk_number != prev_number is true.
The other part of the disjunction doesn't matter since the first part
is true. This means that the if-block is entered.
/* Different chunk, so move pointer. */
d = find_chunk (abfd, chunk_number, must_write);
find_chunk is entered with must_write set to false. Now, remember
where we left off here, because we're going to switch to find_chunk.
static struct data_struct *
find_chunk (bfd *abfd, bfd_vma vma, bool create)
{
(Above 3 lines indented to distinguish code from commentary.)
When we enter find_chunk, create is false because must_write was false.
struct data_struct *d = abfd->tdata.tekhex_data->data;
d is set to NULL since abfd->tdata.texhex_data->data is NULL (one of
the conditions for the scenario).
vma &= ~CHUNK_MASK;
while (d && (d->vma) != vma)
d = d->next;
d is NULL, so the while loop doesn't execute.
if (!d && create)
...
d is NULL so !d is true, but create is false, so the condition
evaluates to false, meaning that the if-block is skipped.
return d;
find_chunk returns NULL, since d is NULL.
Back in move_section_contents:
if (!d)
return false;
d is NULL (because that's what find_chunk returned), so
move_section_contents returns false at this point.
Note that find_section_contents has allocated no memory, nor even
tried to transfer any bytes beyond the first (zero) byte. This
is a bug.
The key to understanding this bug is to observe that find_chunk can
return NULL to indicate that no chunk was found. This is especially
important for the read (get=true) case. But it can also be NULL
to indicate a memory allocation error. I toyed around with the
idea of using a different value to distinguish these cases, i.e.
something like (struct data_struct *) -1, but although bfd contains
plenty of code where -1 is used to indicate various interesting
conditions for scalars, there's no prior art where this is done
for a pointer. Therefore the idea was discarded in favor of
modifying this statement:
if (!d)
return false;
to:
if (!d && must_write)
return false;
This works because, in find_chunk, the only way to return a NULL
memory allocation error is for must_write / create to be true. When
it is true, if bfd_zalloc successfully allocates a chunk, then that
(non-NULL) chunk will be returned at the end of the function. When it
fails, it'll return NULL early. The point is that when bfd_zalloc()
fails and returns NULL, must_write (in move_section_contents) / create
(in find_chunk) HAD to be true. That provides us with an easy test
back in move_section_contents to distinguish a memory-allocation-NULL
from a block-not-found-NULL.
The other NULL return case happens when the end of the function is
reached when either searching for a chunk to read or attempting to
find a chunk to write when abfd->tdata.tekhex_data->data is NULL. But
for the latter case, must_write was false, which does not (now, with
the above fix) trigger the early return of false.
(Alan Modra approved the bfd/tekhex.c change.)
Approved-By: Simon Marchi <simon.marchi@efficios.com> (GDB)
|
|
Change-Id: I3d39ee767a3b2b743b3a90386fb30a6703e9733e
|
|
We can't put a breakpoint in the middle of a ll/sc atomic sequence,
handle the instructions sc.q, llacq.{w/d}, screl.{w/d} newly added
in the LoongArch Reference Manual v1.10 so a ll/sc atomic sequence
using them won't loop forever being debugged.
Signed-off-by: Xi Ruoyao <xry111@xry111.site>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
|
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This commit allows gdb.Color objects to be used to style output from
GDB commands written in Python, and the styled output should work
correctly with pagination.
There are two parts to fixing this:
First, GDB needs to be able to track the currently applied style
within the page_file class. This means that style changes need to be
achieved with calls to pager_file::emit_style_escape.
Now usually, GDB does this by calling something like fprintf_styled,
which takes care to apply the style for us. However, that's not
really an option here as a gdb.Color isn't a full style, and as the
gdb.Color object is designed to be converted directly into escape
sequences that can then be printed, we really need a solution that
works with this approach.
However pager_file::puts already has code in place to handle escape
sequences. Right now all this code does is spot the escape sequence
and append it to the m_wrap_buffer. But in this commit I propose that
we go one step further, parse the escape sequence back into a
ui_file_style object in pager_file::puts, and then we can call
pager_file::emit_style_escape.
If the parsing doesn't work then we can just add the escape sequence
to m_wrap_buffer as we did before.
But wait, how can this work if a gdb.Color isn't a full style? Turns
out that's not a problem. We only ever emit the escape sequence for
those parts of a style that need changing, so a full style that sets
the foreground color will emit the same escape sequence as a gdb.Color
for the foreground. When we convert the escape sequence back into a
ui_file_style, then we get a style with everything set to default,
except the foreground color.
I had hoped that this would be all that was needed. But unfortunately
this doesn't work because of the second problem...
... the implementation of the Python function gdb.write() calls
gdb_printf(), which calls gdb_vprintf(), which calls ui_file::vprintf,
which calls ui_out::vmessage, which calls ui_out::call_do_message, and
finally we reach cli_ui_out::do_message. This final do_message
function does this:
ui_file *stream = m_streams.back ();
stream->emit_style_escape (style);
stream->puts (str.c_str ());
stream->emit_style_escape (ui_file_style ());
If we imagine the case where we are emitting a style, triggered from
Python like this:
gdb.write(gdb.Color('red').escape_sequence(True))
the STYLE in this case will be the default ui_file_style(), and STR
will hold the escape sequence we are writing.
After the first change, where pager_file::puts now calls
pager_file::emit_style_escape, the current style of STREAM will have
been updated. But this means that the final emit_style_escape will
now restore the default style.
The fix for this is to avoid using the high level gdb_printf from
gdb.write(), and instead use gdb_puts instead. The gdb_puts function
doesn't restore the default style, which means our style modification
survives.
There's a new test included. This test includes what appears like a
pointless extra loop (looping over a single value), but this makes
sense given the origin of this patch. I've pulled this commit from a
longer series:
https://inbox.sourceware.org/gdb-patches/cover.1755080429.git.aburgess@redhat.com
I want to get this bug fix merged before GDB 17 branches, but the
longer series is not getting reviews, so for now I'm just merging this
one fix. Once the rest of the series gets merged, I'll be extending
the test, and the loop (mentioned above) will now loop over more
values.
|
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I noticed an out-of-date comment in rust-parse.c.
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After running the testsuite with target board cc-with-gdb-index I ran found
failures in test-cases:
- gdb.dwarf2/backward-spec-inter-cu.exp
- gdb.dwarf2/forward-spec-inter-cu.exp
Fix this by requiring a cooked index.
Tested on x86_64-linux.
|
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Rather than issuing a complaint, which is off by default, warn when returning
false in create_addrmap_from_gdb_index, informing the user that the .gdb_index
was ignored, and why.
Tested on aarch64-linux.
|
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In create_addrmap_from_gdb_index, use the return value of
addrmap_mutable::insert_empty to detect overlapping ranges.
Tested on x86_64-linux.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
|
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Function addrmap_mutable::set_empty has the follow behavior (shortened
comment):
...
/* In the mutable address map MAP, associate the addresses from START
to END_INCLUSIVE that are currently associated with NULL with OBJ
instead. Addresses mapped to an object other than NULL are left
unchanged. */
void set_empty (CORE_ADDR start, CORE_ADDR end_inclusive,
void *obj);
...
Change the return type to bool, and return true if the full range
[START, END_INCLUSIVE] is mapped to OBJ.
Tested on x86_64-linux.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
|
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Currently, in create_addrmap_from_gdb_index, when finding an incorrect entry
in the address table of a .gdb_index section:
- a (by default silent) complaint is made,
- the entry is skipped, and
- the rest of the entries is processed.
This is the use-what-you-can approach, which make sense in general.
But in the case that the .gdb_index section is incorrect while the other debug
info is correct, this approach prevents gdb from building a correct cooked
index (assuming there's no bug in gdb that would cause an incorrect index to
be generated).
Instead, bail out of create_addrmap_from_gdb_index on finding errors in the
address table.
I wonder about the following potential drawback of this approach: in the case
that the .gdb_index section is incorrect because the debug info is incorrect,
this approach rejects the .gdb_index section and spents time rebuilding a
likewise incorrect index. But I'm not sure if this is a real problem.
Perhaps gdb will refuse to generate such an index, in which case this is a
non-issue.
Tested on aarch64-linux.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
|
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The `qSearch:memory` packet uses hex encoding for the address and
length arguments, but the search-pattern argument uses escaped binary.
Approved-By: Eli Zaretskii <eliz@gnu.org>
|
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I forgot one spot when updating the "info shared" header from NS to
"Linker NS", fix that. This fixes the following failure:
FAIL: gdb.base/dlmopen-ns-ids.exp: check no duplicates: info sharedlibrary
At the same time, fix a couple of things I found when looking at this
code again. One is bad indentation, the other is an unnecessary
parameter.
Change-Id: Ibbc2062699264dde08fd3ff7c503524265c73b0c
|
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On an MSYS2 system, I have:
# which tclsh
/mingw64/bin/tclsh
# which tclsh86
/mingw64/bin/tclsh86
# which tclsh8.6
/usr/bin/tclsh8.6
# which expect
/usr/bin/expect
The ones under /usr/bin are MSYS2 programs (linked with msys-2.0.dll).
I.e., they are really Cygwin (unix) ports of the programs.
The ones under /mingw64 are native Windows programs (NOT linked with
msys-2.0.dll). You can check that with CYGWIN/MSYS2 ldd.
The MSYS2/Cygwin port of TCL (and thus expect) does not treat a file
name that starts with a drive letter as an absolute file name, while
the native/MinGW port does. Vis:
# cat file-join.exp
puts [file join c:/ d:/]
# /mingw64/bin/tclsh.exe file-join.exp
d:/
# /mingw64/bin/tclsh86.exe file-join.exp
d:/
# /usr/bin/expect.exe file-join.exp
c:/d:
# /usr/bin/tclsh8.6.exe file-join.exp
c:/d:
When running the testsuite under MSYS2 to test mingw32 (Windows
native) GDB, we use MSYS2 expect (there is no MinGW port of expect
AFAIK). Any TCL file manipulation routine will thus not consider
drive letters special, and just treats them as relative file names.
This results in several cases of the testsuite passing to GDB broken
file names, like:
"C:/foo/C:/foo/bar"
or:
"/c/foo/C:/foo/bar"
E.g., there is a "file join" in standard_output_file that results in
this:
(gdb) file C:/gdb/build/outputs/gdb.base/info_sources_2/C:/gdb/build/outputs/gdb.base/info_sources_2/info_sources_2
C:/gdb/build/outputs/gdb.base/info_sources_2/C:/gdb/build/outputs/gdb.base/info_sources_2/info_sources_2: No such file or directory.
(gdb) ERROR: (info_sources_2) No such file or directory
delete breakpoints
The bad "file join" comes from clean_restart $binfile, where $binfile
is an absolute host file name (thus has a drive letter), clean_restart
doing:
set binfile [standard_output_file ${executable}]
return [gdb_load ${binfile}]
and standard_output_file doing:
# If running on MinGW, replace /c/foo with c:/foo
if { [ishost *-*-mingw*] } {
set dir [exec sh -c "cd ${dir} && pwd -W"]
}
return [file join $dir $basename]
Here, BASENAME was already an absolute file name that starts with a
drive letter, but "file join" treated it as a relative file name.
Another spot where we mishandle Unix vs drive letter file names, is in
the "dir" command that we issue when starting every testcase under
GDB. We currently always pass the file name as seen from the build
machine (i.e., from MSYS2), which is a Unix file name that native
Windows GDB does not understand, resulting in:
(gdb) dir /c/gdb/src/gdb/testsuite/gdb.rocm
warning: /c/gdb/src/gdb/testsuite/gdb.rocm: No such file or directory
Source directories searched: /c/gdb/src/gdb/testsuite/gdb.rocm;$cdir;$cwd
This patch introduces a systematic approach to handle all this, by
introducing the concepts of build file names (what DejaGnu sees) vs
host file names (what GDB sees).
This patches implements that in the following way:
1) - Keep standard_output_file's host-side semantics
standard_output_file currently converts the file name to a Windows
file name, using the "cd $dir; pwd -W" trick. standard_output_file is
used pervasively, so I think it should keep the semantics that it
returns a host file name.
Note there is already a preexisting host_standard_output_file
procedure. The difference to standard_output_file is that
host_standard_output_file handles remote hosts, while
standard_output_file assumes the build and host machines share a
filesystem. The MSYS2 Unix path vs MinGW GDB drive letter case fall
in the "shared filesystem" bucket. An NFS mount on the host at the
same mount point as on the build machine falls in that bucket too.
2) - Introduce build_standard_output_file
In some places, we are calling standard_output_file to find the
build-side file name, most often just to find the standard output
directory file name, and then immediately use that file name with TCL
file manipulation procedures, to do some file manipulation on the
build machine. clean_standard_output_dir is an example of such a
case. That code path is responsible for this bogus 'rm -rf' in
current MSYS2 testing:
Running /c/gdb/src/gdb/testsuite/gdb.base/break.exp ...
Executing on build: rm -rf /c/msys2/home/alves/gdb/build-testsuite/C:/msys2/home/alves/gdb/build-tests...
For these cases, add a variant of standard_output_file called
build_standard_output_file. The main difference to
standard_output_file is that it doesn't do the "cd $dir; pwd -W"
trick. I.e., it returns a path on the build machine.
3) Introduce host_file_sanitize
In some cases, we read an absolute file name out of GDB's output, and
then want to compare it against some other file name. The file name
may originally come from the DWARF, and sometimes may have forward
slashes, and other times, it may have backward slashes. Or the drive
letter may be uppercase, or it may be lowercase. To make comparisons
easier, add a new host_file_sanitize procedure, that normalizes
slashes, and uppercases the drive letter. It does no other
normalization. Particularly, it does not turn a relative file name
into an absolute file name.
It's arguable whether GDB itself should do this sanitization. I
suspect it should. I personally dislike seeing backward slashes in
e.g., "info shared" output, or worse, mixed backward and forward
slashes. Still, I propose starting with a testsuite adjustment that
moves us forward, and handle that separately. I won't be surprised if
we need the new routine for some cases even if we adjust GDB.
4) build_file_normalize / host_file_normalize
In several places in the testsuite, we call "file normalize" on some
file name. If we pass it a drive-letter file name, that TCL procedure
treats the passed in file name as a relative file name, so produces
something like /c/foo/C:/foo/bar.txt.
If the context calls for a build file name, then the "file normalize"
call should produce /c/foo/bar.txt. If OTOH we need a host file name,
then it should produce "C:/foo/bar.txt". Handle this by adding two
procedures that wrap "file normalize":
- build_file_normalize
- host_file_normalize
Initialy I implemented them in a very simple way, calling into
cygpath:
proc build_file_normalize {filename} {
if { [ishost *-*-mingw*] } {
return [exec cygpath -ua $filename]
} else {
return [file normalize $filename]
}
}
proc host_file_normalize {filename} {
if { [ishost *-*-mingw*] } {
return [exec cygpath -ma $filename]
} else {
return [file normalize $filename]
}
}
"cygpath" is a utility that comes OOTB with both Cygwin and MSYS2,
that does Windows <-> Cygwin file name conversion.
This works well, but because running the testsuite on Windows is so
slow, I thought of trying to avoid or minimize the cost of calling an
external utility ("cygpath").
On my system, calling into cygpath takes between 200ms to 350ms, and
these smallish costs (OK, not so small!) can creep up and compound an
already bad situation. Note that the current call to "cd $dir; pwd
-W" has about the same cost as a "cygpath" call (though a little bit
cheaper).
So with this patch, we actually don't call cygpath at all, and no
longer use the "cd $dir; pwd -W" trick. Instead we run the "mount"
command once, and cache the mapping (via gdb_caching_proc) between
Windows file names and Unix mount points, and then use that mapping in
host_file_normalize and build_file_normalize, to do the Windows <=>
Unix file name conversions ourselves.
One other small advantage here is that this approach works the same
for 'cygwin x mingw' testing [1], and 'msys x mingw' testing, while
"pwd -W" only works on MSYS2.
So I think the end result is that we should end up faster (or less
slow) than the current state.
(No, I don't have actual timings for the effect over a whole testsuite
run.)
5) Introduce host_file_join
For the "file join" call done from within standard_output_file (and
probably in future other places), since that procedure works with host
file names, add a new host_file_join procedure that is a wrapper
around "file join" that is aware of Windows drive letters.
======
With the infrastructure described above in place, the "dir" case is
fixed by simply calling host_file_normalize on the directory name,
before passing it to GDB. That turns:
(gdb) dir /c/gdb/src/gdb/testsuite/gdb.base
warning: /c/gdb/src/gdb/testsuite/gdb.base: No such file or directory
Source directories searched: /c/gdb/src/gdb/testsuite/gdb.base;$cdir;$cwd
Into:
(gdb) dir C:/gdb/src/gdb/testsuite/gdb.base
Source directories searched: C:/gdb/src/gdb/testsuite/gdb.base;$cdir;$cwd
Running the testsuite on GNU/Linux reveals that that change requires
tweaks to gdb.guile/scm-parameter.exp and gdb.python/py-parameter.exp,
to run the expected directory by host_file_normalize too, so that it
matches the directory we initially pass GDB at startup time. Without
that fix, there could be a mismatch if the GDB sources path has a
symlink component, which now gets resolved by the host_file_normalize
call.
The theory is that most standard_output_file uses will not need to be
adjusted.
I grepped for "file normalize" and "file join", to find cases that
might need adjustment, and fixed those that required fixing. The
fixes are included in this patch, to make it easier to reason about
the overall change. E.g., in gdb.base/fullname.exp, without the fix,
we get:
Running /c/gdb/src/gdb/testsuite/gdb.base/fullname.exp ...
ERROR: tcl error sourcing /c/gdb/src/gdb/testsuite/gdb.base/fullname.exp.
ERROR: tcl error code NONE
ERROR: C:/msys2/home/alves/gdb/build-testsuite/outputs/gdb.base/fullname/tmp-fullname.c not a subdir of /c/msys2/home/alves/gdb/build-testsuite
In gdb.base/source-dir.exp, we have several issues. E.g., we see the
"/c/foo/c:/foo" problem there too:
dir /c/msys2/home/alves/gdb/build-testsuite/C:/msys2/home/alves/gdb/build-testsuite/outputs/gdb.base/source-dir/C:/msys2/home/alves/gdb/build-testsuite/outputs
warning: /c/msys2/home/alves/gdb/build-testsuite/C:/msys2/home/alves/gdb/build-testsuite/outputs/gdb.base/source-dir/C:/msys2/home/alves/gdb/build-testsuite/outputs: No such file or directory
Source directories searched: /c/msys2/home/alves/gdb/build-testsuite/C:/msys2/home/alves/gdb/build-testsuite/outputs/gdb.base/source-dir/C:/msys2/home/alves/gdb/build-testsuite/outputs;$cdir;$cwd
(gdb) PASS: gdb.base/source-dir.exp: setup source path search directory
...
Executing on host: x86_64-w64-mingw32-gcc \
-fno-stack-protector \
/c/msys2/home/alves/gdb/build-testsuite/C:/msys2/home/alves/gdb/build-testsuite/outputs/gdb.base/macro-source-path/cwd/macro-source-path.c ...
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
... and we need to handle Unix file names that we pass to the compiler
(on the build side), vs file names that GDB prints out (the host
side).
Similarly in the other testcases.
I haven't yet tried to do a full testsuite run on MSYS2, and I'm quite
confident there will be more places that will need similar adjustment,
but I'd like to land the infrastructure early, so that the rest of the
testsuite can be adjusted incrementally, and others can help.
Change-Id: I664dbb86d0efa4fa8db405577bea2b4b4a96a613
|
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During the last new year process, it seems that we forgot to update the
copyright notices printed by the various programs (see 713b99a9398 "gdb,
gdbserver: update copyright years in copyright notices"). Change
gdb/copyright.py to print a message about this. For a procedure that
happens once a year, this seems sufficient to me, but if someone wants
to automate it I won't object.
While at it, change the formatting of the previous message, to match the
formatting of the first message (making it end with a colon).
Change-Id: I330f566221d102bab0a953bc324127f2466dd5cf
Approved-By: Tom Tromey <tom@tromey.com>
|
|
There are a good number of testcases in the testsuite that use alarm()
as a watchdog that aborts the test if something goes wrong.
alarm()/SIG_ALRM do not exist on (native) Windows, so those tests fail
to compile there.
For example, testing with x86_64-w64-mingw32-gcc, we see:
Running /c/rocgdb/src/gdb/testsuite/gdb.base/attach.exp ...
gdb compile failed, C:/rocgdb/src/gdb/testsuite/gdb.base/attach.c: In function 'main':
C:/rocgdb/src/gdb/testsuite/gdb.base/attach.c:17:3: error: implicit declaration of function 'alarm' [-Wimplicit-function-declaration]
17 | alarm (60);
| ^~~~~
While testing with a clang configured to default to
x86_64-pc-windows-msvc, which uses the C/C++ runtime headers from
Visual Studio and has no unistd.h, we get:
Running /c/rocgdb/src/gdb/testsuite/gdb.base/attach.exp ...
gdb compile failed, C:/rocgdb/src/gdb/testsuite/gdb.base/attach.c:8:10: fatal error: 'unistd.h' file not found
8 | #include <unistd.h>
| ^~~~~~~~~~
Handle this by adding a new testsuite/lib/gdb_watchdog.h header that
defines a new gdb_watchdog function, which wraps alarm on Unix-like
systems, and uses a timer on Windows.
This patch adjusts gdb.base/attach.c as example of usage. Testing
gdb.base/attach.exp with clang/x86_64-pc-windows-msvc required a
related portability tweak to can_spawn_for_attach, to not rely on
unistd.h on Windows.
gdb.rocm/mi-attach.cpp is another example adjusted, one which always
runs with clang configured as x86_64-pc-windows-msvc on Windows (via
hipcc).
Approved-by: Kevin Buettner <kevinb@redhat.com>
Change-Id: I3b07bcb60de039d34888ef3494a5000de4471951
|
|
Instead of manually calling lappend_include_file in every testcase
that needs to include a file in testsuite/lib/, handle testsuite/lib/
includes automatically in gdb_compile.
As an example, gdb.base/backtrace.exp is adjusted to no longer
explicitly call lappend_include_file for testsuite/lib/attributes.h.
Tested on x86-64 GNU/Linux with both:
$ make check RUNTESTFLAGS=" \
--host_board=local-remote-host-native \
--target_board=local-remote-host-native \
HOST_DIR=/tmp/foo/" \
TESTS="gdb.base/backtrace.exp"
and:
$ make check TESTS="gdb.base/backtrace.exp"
and confirming that the testcase still compiles and passes cleanly.
Also ran full testsuite on x86-64 GNU/Linux in normal mode.
Approved-by: Kevin Buettner <kevinb@redhat.com>
Change-Id: I5ca77426ea4a753a995c3ad125618c02cd952576
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|
When running a program that uses multiple linker namespaces, I get
something like:
$ ./gdb -nx -q --data-directory=data-directory testsuite/outputs/gdb.base/dlmopen-ns-ids/dlmopen-ns-ids -ex "tb 50" -ex r -ex "info shared" -batch
...
From To NS Syms Read Shared Object Library
0x00007ffff7fc6000 0x00007ffff7fff000 0 Yes /lib64/ld-linux-x86-64.so.2
0x00007ffff7e93000 0x00007ffff7f8b000 0 Yes /usr/lib/libm.so.6
0x00007ffff7ca3000 0x00007ffff7e93000 0 Yes /usr/lib/libc.so.6
0x00007ffff7fb7000 0x00007ffff7fbc000 1 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/dlmopen-ns-ids/dlmopen-lib.so
0x00007ffff7b77000 0x00007ffff7c6f000 1 Yes /usr/lib/libm.so.6
0x00007ffff7987000 0x00007ffff7b77000 1 Yes /usr/lib/libc.so.6
0x00007ffff7fc6000 0x00007ffff7fff000 1 Yes /usr/lib/ld-linux-x86-64.so.2
0x00007ffff7fb2000 0x00007ffff7fb7000 2 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/dlmopen-ns-ids/dlmopen-lib.so
0x00007ffff788f000 0x00007ffff7987000 2 Yes /usr/lib/libm.so.6
0x00007ffff769f000 0x00007ffff788f000 2 Yes /usr/lib/libc.so.6
0x00007ffff7fc6000 0x00007ffff7fff000 1! Yes /usr/lib/ld-linux-x86-64.so.2
0x00007ffff7fad000 0x00007ffff7fb2000 3 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.base/dlmopen-ns-ids/dlmopen-lib.so
0x00007ffff75a7000 0x00007ffff769f000 3 Yes /usr/lib/libm.so.6
0x00007ffff73b7000 0x00007ffff75a7000 3 Yes /usr/lib/libc.so.6
0x00007ffff7fc6000 0x00007ffff7fff000 1! Yes /usr/lib/ld-linux-x86-64.so.2
Some namespace IDs for the dynamic linker entries (ld-linux) are wrong
(I placed a ! next to those that are wrong).
The dynamic linker is special: it is loaded only once (notice how all
ld-linux entries have the same addresses), but it is visible in all
namespaces. It is therefore listed separately in all namespaces.
The problem happens like this:
- for each solib, print_solib_list_table calls solib_ops::find_solib_ns
to get the namespace ID to print
- svr4_solib_ops::find_solib_ns calls find_debug_base_for_solib
- find_debug_base_for_solib iterates on the list of solibs in all
namespaces, looking for a match for the given solib. For this, it
uses svr4_same, which compares two SOs by name and low address.
Because there are entries for the dynamic linker in all namespaces,
with the same low address, find_debug_base_for_solib is unable to
distinguish them, and sometimes returns the wrong namespace.
To fix this, save in lm_info_svr4 the debug base address that this
lm/solib comes from, as a way to distinguish two solibs that would be
otherwise identical.
The code changes are:
- Add a constructor to lm_info_svr4 accepting the debug base. Update
all callers, which sometimes requires passing down the debug base.
- Modify find_debug_base_for_solib to return the debug base directly
from lm_info_svr4.
- Modify svr4_same to consider the debug base value of the two
libraries before saying they are the same. While at it, move the
address checks before the name check, since they are likely less
expensive to do.
- Modify svr4_solib_ops::default_debug_base to update the debug base of
existing solibs when the default debug base becomes known.
I found the last point to be necessary, because when running an
inferior, we list the shared libraries very early (before the first
instruction):
#0 svr4_solib_ops::current_sos (this=0x7c1ff1e09710)
#1 0x00005555643c774e in update_solib_list (from_tty=0)
#2 0x00005555643ca377 in solib_add (pattern=0x0, from_tty=0, readsyms=1)
#3 0x0000555564335585 in svr4_solib_ops::enable_break (this=0x7c1ff1e09710, info=0x7d2ff1de8c40, from_tty=0)
#4 0x000055556433c85c in svr4_solib_ops::create_inferior_hook (this=0x7c1ff1e09710, from_tty=0)
#5 0x00005555643d22cb in solib_create_inferior_hook (from_tty=0)
#6 0x000055556337071b in post_create_inferior (from_tty=0, set_pspace_solib_ops=true)
#7 0x00005555633726a2 in run_command_1 (args=0x0, from_tty=0, run_how=RUN_NORMAL)
#8 0x0000555563372b35 in run_command (args=0x0, from_tty=0)
At this point, the dynamic linker hasn't yet filled the DT_DEBUG slot,
which normally points at the base of r_debug. Since we're unable to
list shared libraries at this point, we go through
svr4_solib_ops::default_sos, which creates an solib entry for the
dynamic linker. At this point, we have no choice but to create it with
a debug base of 0 (or some other value that indicates "unknown"). If we
left it as-is, then it would later not be recognized to be part of any
existing namespace and that would cause problems down the line.
With this change, the namespaces of the dynamic linker become correct.
I was not sure if the code in library_list_start_library was conflating
debug base and lmid. The documentation says this about the "lmid" field
in the response of a qxfer:libraries-svr4:read packet:
lmid, which is an identifier for a linker namespace, such as the
memory address of the r_debug object that contains this namespace’s
load map or the namespace identifier returned by dlinfo (3).
When I read "lmid", I typically think about "the namespace identifier
returned by dlinfo (3)". In library_list_start_library, we use the
value of the "lmid" attribute as the debug base address. This is the
case even before this patch, since we do:
solist = &list->solib_lists[lmid];
The key for the solib_lists map is documented as being the debug base
address. In practice, GDBserver uses the debug base address for the
"lmid" field, so we're good for now.
If the remote side instead used "the namespace identifier returned by
dlinfo (3)" (which in practice with glibc are sequential integers
starting at 0), I think we would be mostly fine. If we use the qxfer
packet to read the libraries, we normally won't use the namespace base
address to do any memory reads, as all the information comes from the
XML. There might be some problems however because we treat the
namespace 0 specially, for instance in
svr4_solib_ops::update_incremental. In that case, we might need a
different way of indicating that the remote side does not give namespace
information than using namespace 0. This is just a thought for the
future.
I improved the existing test gdb.base/dlmopen-ns-ids.exp to verify that
"info sharedlibrary" does not show duplicate libraries, duplicate
meaning same address range, namespace and name.
Change-Id: I84467c6abf4e0109b1c53a86ef688b934e8eff99
Reviewed-By: Guinevere Larsen <guinevere@redhat.com>
|
|
When running an inferior, solib_ops_svr4::current_sos is called very
early, at a point where the default debug base is not yet accessible.
The inferior is stopped at its entry point, before the dynamic linker
had the time to fill the DT_DEBUG slot. It only becomes available a
little bit later. In a following patch, I will want to do some action
when the debug base becomes known (namely, update the debug base in the
previously created lm_info_svr4 instances).
For this reason, add the svr4_solib_ops::default_debug_base method to
centralize where we fetch the default debug base. I will then be able
to add my code there, when detecting the debug base changes.
This patch brings the following behavior change: since all
svr4_solib_ops entry points now use svr4_solib_ops::default_debug_base
to get the debug base value, they will now all re-fetch the value from
the inferior. Previously, this was not done consistently, only in two
spots. It seems to me like it would be good to be consistent about
that, because we can't really predict which methods will get called in
which order in all scenarios.
Some internal methods still access svr4_info::default_debug_base
directly, because it is assumed that their caller would have used
svr4_solib_ops::default_debug_base, updating the value in
svr4_info::default_debug_base if necessary.
Change-Id: Ie08da34bbb3ad6fd317c0e5802c5c94d8c7d1ce5
Reviewed-By: Guinevere Larsen <guinevere@redhat.com>
|
|
solib_ops
Change the "iterate over objfiles in search order" operation from a
gdbarch method to methods on both program_space and solib_ops.
The first motivation for this is that I want to encapsulate solib-svr4's
data into svr4_solib_ops (in a subsequent series), instead of it being
in a separate structure (svr4_info). It is awkward to do so as long as
there are entry points that aren't the public solib_ops interface.
The second motivation is my project of making it able to have multiple
solib_ops per program space (which should be the subject of said
subsequent series), to better support heterogenousa systems (like ROCm,
with CPU and GPU in the same inferior). When we have this, when stopped
in GPU code, it won't make sense to ask the host's architecture to do
the iteration, as the logic could be different for the GPU architecture.
Instead, program_space::iterate_over_objfiles_in_search_order will be
responsible to delegate to the various solib_ops using a logic that is
yet to be determined.
I included this patch in this series (rather than the following one)
so that svr4_solib_ops::iterate_over_objfiles_in_search_order can access
svr4_solib_ops::default_debug_base, introduced in a later patch in this
series.
default_iterate_over_objfiles_in_search_order becomes the default
implementation of solib_ops::iterate_over_objfiles_in_search_order.
As far as I know, all architectures using
svr4_iterate_over_objfiles_in_search_order also use solib_ops_svr4, so I
don't expect this patch to cause behavior changes.
Change-Id: I71f8a800b8ce782ab973af2f2eb5fcfe4e06ec76
Reviewed-By: Guinevere Larsen <guinevere@redhat.com>
|
|
This makes it a bit clearer that it compares shared libraries by name.
While at it, change the return type to bool.
Change-Id: Ib11a931a0cd2e00bf6ae35c5b6e0d620298d46cb
Reviewed-By: Guinevere Larsen <guinevere@redhat.com>
|
|
Add this function, as a shortcut of doing the more verbose:
auto *li = gdb::checked_static_cast<lm_info_svr4 &> (*solib.lm_info);
Change-Id: I0206b3a8b457bdb276f26b354115e8f44416dfcf
Reviewed-By: Guinevere Larsen <guinevere@redhat.com>
|
|
In some subsequent patches, solib_ops methods will need to access the
program space they were created for. We currently access the program
space using "current_program_space", but it would better to remember the
program space at construction time instead.
Change-Id: Icf2809435a23c47ddeeb75e603863b201eff2e58
Reviewed-By: Guinevere Larsen <guinevere@redhat.com>
|
|
I would like to propose some minor changes to the format of "info linker
namespaces" and "info sharedlibrary", to make it a bit tidier and less
chatty.
Here are the current formats (I replaced empty lines with dots, so that
git doesn't collapse them):
(gdb) info linker-namespaces
There are 3 linker namespaces loaded
There are 5 libraries loaded in linker namespace [[0]]
Displaying libraries for linker namespace [[0]]:
From To Syms Read Shared Object Library
0x00007ffff7fc6000 0x00007ffff7fff000 Yes /lib64/ld-linux-x86-64.so.2
0x00007ffff7e94000 0x00007ffff7f8c000 Yes /usr/lib/libm.so.6
0x00007ffff7ca4000 0x00007ffff7e94000 Yes /usr/lib/libc.so.6
0x00007ffff7fad000 0x00007ffff7fb2000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7fa8000 0x00007ffff7fad000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
.
.
There are 6 libraries loaded in linker namespace [[1]]
Displaying libraries for linker namespace [[1]]:
From To Syms Read Shared Object Library
0x00007ffff7fb7000 0x00007ffff7fbc000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7fb2000 0x00007ffff7fb7000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
0x00007ffff7b79000 0x00007ffff7c71000 Yes /usr/lib/libm.so.6
0x00007ffff7989000 0x00007ffff7b79000 Yes /usr/lib/libc.so.6
0x00007ffff7fc6000 0x00007ffff7fff000 Yes /usr/lib/ld-linux-x86-64.so.2
0x00007ffff7f99000 0x00007ffff7f9e000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.2.so
.
.
There are 5 libraries loaded in linker namespace [[2]]
Displaying libraries for linker namespace [[2]]:
From To Syms Read Shared Object Library
0x00007ffff7fc6000 0x00007ffff7fff000 Yes /usr/lib/ld-linux-x86-64.so.2
0x00007ffff7fa3000 0x00007ffff7fa8000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7f9e000 0x00007ffff7fa3000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
0x00007ffff7891000 0x00007ffff7989000 Yes /usr/lib/libm.so.6
0x00007ffff76a1000 0x00007ffff7891000 Yes /usr/lib/libc.so.6
(gdb) info sharedlibrary
From To NS Syms Read Shared Object Library
0x00007ffff7fc6000 0x00007ffff7fff000 [[0]] Yes /lib64/ld-linux-x86-64.so.2
0x00007ffff7e94000 0x00007ffff7f8c000 [[0]] Yes /usr/lib/libm.so.6
0x00007ffff7ca4000 0x00007ffff7e94000 [[0]] Yes /usr/lib/libc.so.6
0x00007ffff7fb7000 0x00007ffff7fbc000 [[1]] Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7fb2000 0x00007ffff7fb7000 [[1]] Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
0x00007ffff7b79000 0x00007ffff7c71000 [[1]] Yes /usr/lib/libm.so.6
0x00007ffff7989000 0x00007ffff7b79000 [[1]] Yes /usr/lib/libc.so.6
0x00007ffff7fc6000 0x00007ffff7fff000 [[1]] Yes /usr/lib/ld-linux-x86-64.so.2
0x00007ffff7fad000 0x00007ffff7fb2000 [[0]] Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7fa8000 0x00007ffff7fad000 [[0]] Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
0x00007ffff7fa3000 0x00007ffff7fa8000 [[2]] Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7f9e000 0x00007ffff7fa3000 [[2]] Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
0x00007ffff7891000 0x00007ffff7989000 [[2]] Yes /usr/lib/libm.so.6
0x00007ffff76a1000 0x00007ffff7891000 [[2]] Yes /usr/lib/libc.so.6
0x00007ffff7fc6000 0x00007ffff7fff000 [[1]] Yes /usr/lib/ld-linux-x86-64.so.2
0x00007ffff7f99000 0x00007ffff7f9e000 [[1]] Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.2.so
Here is what I would change:
- I find that the [[...]] notation used everywhere is heavy and noisy.
I understand that this is the (proposed) notation for specifying a
namespace id in an expression. But I don't think it's useful to
print those brackets everywhere (when it's obvious from the context
that the number is a namespace id). I would remove them from the
messages and from the tables.
- I find these lines a bit too verbose:
There are X libraries loaded in linker namespace [[Y]]
Displaying libraries for linker namespace [[Y]]:
I think they can be condensed to a single line, without loss of
information (I think that printing the number of libs in each
namespace is not essential, but I don't really mind, so I left it
there).
- I would add an empty line after the "There are N linker namespaces
loaded" message, to visually separate it from the first group. I
would also finish that line with a period.
- There are two empty lines between each group I think that one empty
line is sufficient to do a visual separation.
Here's how it looks with this patch:
(gdb) info linker-namespaces
There are 3 linker namespaces loaded.
5 libraries loaded in linker namespace 0:
From To Syms Read Shared Object Library
0x00007ffff7fc6000 0x00007ffff7fff000 Yes /lib64/ld-linux-x86-64.so.2
0x00007ffff7e94000 0x00007ffff7f8c000 Yes /usr/lib/libm.so.6
0x00007ffff7ca4000 0x00007ffff7e94000 Yes /usr/lib/libc.so.6
0x00007ffff7fad000 0x00007ffff7fb2000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7fa8000 0x00007ffff7fad000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
6 libraries loaded in linker namespace 1:
From To Syms Read Shared Object Library
0x00007ffff7fb7000 0x00007ffff7fbc000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7fb2000 0x00007ffff7fb7000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
0x00007ffff7b79000 0x00007ffff7c71000 Yes /usr/lib/libm.so.6
0x00007ffff7989000 0x00007ffff7b79000 Yes /usr/lib/libc.so.6
0x00007ffff7fc6000 0x00007ffff7fff000 Yes /usr/lib/ld-linux-x86-64.so.2
0x00007ffff7f99000 0x00007ffff7f9e000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.2.so
5 libraries loaded in linker namespace 2:
From To Syms Read Shared Object Library
0x00007ffff7fc6000 0x00007ffff7fff000 Yes /usr/lib/ld-linux-x86-64.so.2
0x00007ffff7fa3000 0x00007ffff7fa8000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7f9e000 0x00007ffff7fa3000 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
0x00007ffff7891000 0x00007ffff7989000 Yes /usr/lib/libm.so.6
0x00007ffff76a1000 0x00007ffff7891000 Yes /usr/lib/libc.so.6
(gdb) info shared
From To Linker NS Syms Read Shared Object Library
0x00007ffff7fc6000 0x00007ffff7fff000 0 Yes /lib64/ld-linux-x86-64.so.2
0x00007ffff7e94000 0x00007ffff7f8c000 0 Yes /usr/lib/libm.so.6
0x00007ffff7ca4000 0x00007ffff7e94000 0 Yes /usr/lib/libc.so.6
0x00007ffff7fb7000 0x00007ffff7fbc000 1 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7fb2000 0x00007ffff7fb7000 1 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
0x00007ffff7b79000 0x00007ffff7c71000 1 Yes /usr/lib/libm.so.6
0x00007ffff7989000 0x00007ffff7b79000 1 Yes /usr/lib/libc.so.6
0x00007ffff7fc6000 0x00007ffff7fff000 1 Yes /usr/lib/ld-linux-x86-64.so.2
0x00007ffff7fad000 0x00007ffff7fb2000 0 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7fa8000 0x00007ffff7fad000 0 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
0x00007ffff7fa3000 0x00007ffff7fa8000 2 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.1.so
0x00007ffff7f9e000 0x00007ffff7fa3000 2 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib-dep.so
0x00007ffff7891000 0x00007ffff7989000 2 Yes /usr/lib/libm.so.6
0x00007ffff76a1000 0x00007ffff7891000 2 Yes /usr/lib/libc.so.6
0x00007ffff7fc6000 0x00007ffff7fff000 1 Yes /usr/lib/ld-linux-x86-64.so.2
0x00007ffff7f99000 0x00007ffff7f9e000 1 Yes /home/smarchi/build/binutils-gdb/gdb/testsuite/outputs/gdb.mi/mi-dlmopen/dlmopen-lib.2.so
Change-Id: Iefad340f7f43a15cff24fc8e1301f91d3d7f0278
Reviewed-By: Guinevere Larsen <guinevere@redhat.com>
|
|
On Arch Linux, I get:
FAIL: gdb.base/dlmopen-ns-ids.exp: reopen a namespace
The symptom observed is that after stepping over the last dlmopen of the
test, "info sharedlibrary" does not show the library just opened. After
digging, I found that when stepping over that dlmopen call, the shlib
event breakpoint (that GDB inserts in glibc to get notified of dynamic
linker activity) does not get hit. I then saw that after the previous
dlclose, the shlib event breakpoints were suddenly all marked as
pending:
(gdb) maintenance info breakpoints
Num Type Disp Enb Address What
-1 shlib events keep n <PENDING>
-1.1 y- <PENDING>
The root cause of this problem is the fact that the dynamic linker path
specified in binaries contains a symlink:
$ readelf --program-headers /bin/ls | grep "Requesting program interpreter"
[Requesting program interpreter: /lib64/ld-linux-x86-64.so.2]
$ ls -l /lib64
lrwxrwxrwx 1 root root 7 May 3 15:26 /lib64 -> usr/lib
$ realpath /lib64/ld-linux-x86-64.so.2
/usr/lib/ld-linux-x86-64.so.2
As a result, the instances of the dynamic linker in the non-base
namespace have the real path instead of the original path:
(gdb) info sharedlibrary
From To NS Syms Read Shared Object Library
0x00007ffff7fc6000 0x00007ffff7fff000 [[0]] Yes /lib64/ld-linux-x86-64.so.2
...
0x00007ffff7fc6000 0x00007ffff7fff000 [[1]] Yes /usr/lib/ld-linux-x86-64.so.2
...
0x00007ffff7fc6000 0x00007ffff7fff000 [[1]] Yes /usr/lib/ld-linux-x86-64.so.2
...
0x00007ffff7fc6000 0x00007ffff7fff000 [[1]] Yes /usr/lib/ld-linux-x86-64.so.2
Notice that all instances of the dynamic loader have the same address
range. This is expected: the dynamic loader is really loaded just once
in memory, it's just that it's visible in the various namespaces, so
listed multiple times. Also, notice that the last three specify
namespace 1... seems like a separate bug to me (ignore it for now).
The fact that the paths differ between the first one and the subsequent
ones is not something we control: we receive those paths as-is from the
glibc link map.
Since these multiple solib entries are really the same mapping, we would
expect this code in solib_read_symbols to associate them to the same
objfile:
/* Have we already loaded this shared object? */
so.objfile = nullptr;
for (objfile *objfile : current_program_space->objfiles ())
{
if (filename_cmp (objfile_name (objfile), so.name.c_str ())
== 0
&& objfile->addr_low == so.addr_low)
{
so.objfile = objfile;
break;
}
}
But because the filenames differ, we end up creating two different
objfiles with the same symbols, same address ranges, etc. I would guess
that this is not a state we want.
When the dlclose call closes the last library from the non-base
namespace, the dynamic linker entry for that namespace is also
removed. From GDB's point of view, it just looks like an solib getting
unloaded. In update_solib_list, we have this code to check if the
objfile behind the solib is used by other solibs, and avoid deleting the
objfile if so:
bool still_in_use
= (gdb_iter->objfile != nullptr
&& solib_used (current_program_space, *gdb_iter));
/* Notify any observer that the shared object has been
unloaded before we remove it from GDB's tables. */
notify_solib_unloaded (current_program_space, *gdb_iter,
still_in_use, false);
/* Unless the user loaded it explicitly, free SO's objfile. */
if (gdb_iter->objfile != nullptr
&& !(gdb_iter->objfile->flags & OBJF_USERLOADED)
&& !still_in_use)
gdb_iter->objfile->unlink ();
Because this is the last solib to use that objfile instance, the objfile
is deleted. In the process, disable_breakpoints_in_unloaded_shlib (in
breakpoint.c) is called. The breakpoint locations for the shlib event
breakpoints get marked as "shlib_disabled", which then causes them (I
suppose) to not get inserted and be marked as pending. And then, when
stepping on the subsequent dlmopen call, GDB misses the load of the new
library.
It seems clear to me that, at least, the duplicate objfile detection in
solib_read_symbols needs to be fixed. Right now, to conclude that an
solib matches an existing objfile, it checks that:
- the two have equivalent paths (filename_cmp)
- the two have the same "low" address
In this patch, I remove the filename check. This makes it such that all
the solibs for dynamic linker entries will share the same objfile.
This assumes that no two different solibs / objfiles will have the same
low address. At first glance, it seems like a reasonable assumption to
make, but I don't know if there are some corner cases where this is not
true.
To fix my specific case, I could change the code to resolve the symlinks
and realize that these are all the same file. But I don't think it
would work in a general way. For example, if debugging remotely and
using the target: filesystem, we would need to resolve the symlink on
the target, and I don't think we can do that today (there is no
readlink/realpath operation in the target file I/O).
With this patch, gdb.base/dlmopen-ns-ids.exp passes cleanly:
# of expected passes 44
Change-Id: I3b60051085fb9597b7a72f50122c1104c969908e
Reviewed-By: Guinevere Larsen <guinevere@redhat.com>
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When connecting to a GDBserver 12, which doesn't have support for
non-default linker namespaces and the "lmid" attribute in the
qxfer:libraries-svr4:read response, I get:
(gdb) c
Continuing.
⚠️ warning: while parsing target library list (at line 1): Required attribute "lmid" of <library> not specified
Given the code in library_list_start_library, I understand that the
"lmid" attribute is meant to be optional. Mark it as optional in the
attribute descriptions, to avoid this warning.
Change-Id: Ieb10ee16e36bf8a771f944006e7ada1c10f6fbdc
Reviewed-By: Guinevere Larsen <guinevere@redhat.com>
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On my Arch Linux system*, the dynamic linker path specified in ELF
binaries contains a symlink:
$ readelf --program-headers /bin/ls | grep "Requesting program interpreter"
[Requesting program interpreter: /lib64/ld-linux-x86-64.so.2]
$ ls -l /lib64
lrwxrwxrwx 1 root root 7 May 3 15:26 /lib64 -> usr/lib
$ realpath /lib64/ld-linux-x86-64.so.2
/usr/lib/ld-linux-x86-64.so.2
Because of this, some dlmopen tests think that the dynamic linker
doesn't appear multiple times, when it in fact does (under two different
names), and some parts of the test are disabled:
UNSUPPORTED: gdb.base/dlmopen.exp: test_solib_unmap_events: multiple copies of the dynamic linker not found
Make the tests compute the real path of the dynamic linker and accept
that as valid path for the dynamic linker.
With this patch, I go from
# of expected passes 92
to
# of expected passes 98
* On my Ubuntu 24.04 system, the dynamic linker appears to be a symlink
too, but the glibc is too old to show the dynamic linker in the
non-default namespace.
Change-Id: I03867f40e5313816bd8a8401b65713ddef5d620e
Reviewed-By: Guinevere Larsen <guinevere@redhat.com>
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I spotted a few cases where the return value of PyObject_New was not
being checked against nullptr, but we were dereferencing the result.
All fixed here. The fixed functions can now return NULL, so I checked
all the callers, and I believe there will handle a return of NULL
correctly.
Assuming calls to PyObject_New never fail, there should be no user
visible changes after this commit.
No tests here as I don't know how we'd go about causing a Python
object allocation to fail.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
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This commit reworks the _active_linker_namespaces convenience variable
following Simon's feedback here:
https://sourceware.org/pipermail/gdb-patches/2025-August/219938.html
This patch implements the renaming to _linker_namespace_count (following
the standard set by _inferior_thread_count) and makes the convenience
variable more resilient in the multi-inferior case by providing a new
function, solib_linker_namespace_count, which counts gets the count of
namespaces using the solib_ops of the provided program_space
Approved-By: Simon Marchi <simon.marchi@efficios.com>
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This function can't return a NULL pointer, so make it return a reference
instead.
Change-Id: I0970d6d0757181291b300bd840037a48330a7fbb
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