| Age | Commit message (Collapse) | Author | Files | Lines |
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While stepping through gdb.reverse/time-reverse.exp I realized that we're
recording the instructions for resolving the PLT entries for functions time
and syscall, while that's not really the focus of the test-case.
Limit the scope of the test, by calling the functions once before starting
to record.
Also call "info record" after recording to make it clear how many
instructions were recorded.
On x86_64-linux, before this patch (but with info record added), we have:
...
$ grep "Log contains" gdb.log
Log contains 750 instructions.
Log contains 1218 instructions.
...
and with this patch we have:
...
$ grep "Log contains" gdb.log
Log contains 24 instructions.
Log contains 19 instructions.
...
Tested on x86_64-linux.
Approved-By: Guinevere Larsen <guinevere@redhat.com>
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Tom de Vries reported that some of the test for the vmov[u|a]p[s|d] were
failing. In my machine xmm3 was consistently set to 0x54, but apparently
that is different depending on the system. This commit zeroes out xmm3
at the start of the test instead.
While debugging the test failures, I also noticed an issue where the
recording wasn't saving all the required memory. That happened because
vmovs[s|d] shares its opcode with vmovap[s|d], meaning they seem to
share code paths, but the latter encodes memory modification size on
VEX.L whereas the former encodes in VEX.pp. So this commit fixed that,
and made the relevant tests more robust and complete.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=32561
Approved-By: Guinevere Larsen <guinevere@redhat.com>
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The test gdb.reverse/i386-avx-reverse.exp requires CPU to have AVX
instructions but it actually also uses AVX2 instructions (like
vpcmpeqd). This caused the test to fail on CPUs that have AVX but not
AVX2.
This commit adds check for AVX2.
Tested on Intel Xeon CPU E3-1265L (no AVX2) and Intel Core i7-1355U
(has AVX2).
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This commit adds support for the following types of instructions
relating to floating poitn values: add, mul, sub, min, div, max.
These are supported with packed or single values, and single or double
precision.
Some of the instructions had opcode clashes, however, considering the
mechanics of recording the registers is the same on both instructions,
this is just marked with a comment.
Approved-By: Guinevere Larsen <guinevere@redhat.com>
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This commit adds support for the AVX instructions vunpck[l|h][ps|pd]
instructions, which was pretty straightforward.
This commit also fixes a mistake in the test, where "record stop" was
used after the recording was already stopped, if it failed during
vpunpck_test recording. It also improved the documentation at the start
of the relevant .c function.
Approved-By: Guinevere Larsen <guinevere@redhat.com>
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This commit updates GDB's record-full to be able to record vmov[ss|sd]
and vmov [u|a] [ps|pd] AVX instructions, and tests for them.
Unlike the vmovdq[u|a] instructions, the aligned and unalgined versions
of vmov?[ps|pd] have different opcodes. The mechanics of recording them
is the same, but the aligned version has opcodes 0x28 and 0x29, while
the unaligned has the same opcode as vmov[ss|sd] instruction, 0x10 and
0x11.
Approved-By: Guinevere Larsen <guinevere@redhat.com>
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gdb.reverse/test_ioctl_TCSETSW.exp
I ran test-case gdb.reverse/test_ioctl_TCSETSW.exp on riscv64-linux, and got:
...
(gdb) record full^M
Process record: the current architecture doesn't support record function.^M
(gdb) FAIL: gdb.reverse/test_ioctl_TCSETSW.exp: record full
...
Fix this by requiring supports_process_record.
Tested on riscv64-linux and x86_64-linux.
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The test gdb.reverse/i386-avx-reverse.exp was assuming that if the CPU
was like x86, it would have AVX instructions because I didn't know how
to check for AVX instruction support explicitly. This commit updates
that to use the pre-existing TCL proc have_avx.
Also update the comment at the top of the test, since it was a copy of a
different test.
Approved-By: Andrew Burgess <aburgess@redhat.com>
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This commit adds recording support for the AVX instruction vpor, and the
AVX2 extension. Since the encoding of vpor and vpxor are the same, and
their semantics are basically the same, modulo the mathematical
operation, they are handled by the same switch case block.
This also updates the vpxor function, to test vpor and vpxor, and
updates the name to vpor_xor_test to better reflect what it does.
Approved-By: Tom Tromey <tom@tromey.com>
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This commit adds support for recording the AVX instruction vpmovmskb,
and tests to the relevant file. The test didn't really support checking
general purpose registers, so this commit also adds a proc to
gdb.reverse/i386-avx-reverse.exp, which can be used to test them
Approved-By: Tom Tromey <tom@tromey.com>
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This commit adds support to recording instructions of the form
VPCMPEQ[B|W|D]. They are all encoded in the same way and only
differentiated by the opcode, so they are all processed together. This
commit also updates the test to (quite exhaustively) test the new
instruction.
Approved-By: Tom Tromey <tom@tromey.com>
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This commit adds support for recording the instruction vpxor,
introduced in the AVX extension, and extended in AVX2 to use 256 bit
registers. The test gdb.reverse/i386-avx-reverse.exp has been extended
to test this instruction as well.
Approved-By: Tom Tromey <tom@tromey.com>
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Currently, text adjacent to parentheses is not spell-checked:
...
$ cat tmp.txt
(upto)
$ ./gdb/contrib/spellcheck.sh tmp.txt
$
...
Add handling of parentheses, such that we get:
...
$ ./gdb/contrib/spellcheck.sh tmp.txt
upto -> up to
$
...
Rerun spellcheck.sh, resulting in a few "thru->through" replacements.
Tested on x86_64-linux.
Approved-by: Kevin Buettner <kevinb@redhat.com>
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The test gdb.reverse/i386-avx-reverse.exp was changed by the recent
commit:
commit 5bf288d5a88ab6d3fa9bd7bd070e624afd264dc6
Author: Guinevere Larsen <guinevere@redhat.com>
Date: Fri Jul 26 17:31:14 2024 -0300
gdb/record: support AVX instructions VMOVDQ(U|A) when recording
In that commit I added a few calls to the instruction vmovdqa to and
from memory addresses. Because my local gcc testing always had aligned
pointers, I thought this would always work, but clang (and maybe other
compilers) might not do the same, which will cause vmovdqa to segfault,
and the test to fail spectacularly.
This commit fixes that by using the pre-existing precise-aligned-alloc
to allocate the dynamic buffers, forcing them to be aligned to the
required boundary for vmovdqa instruction to work. The code was then
re-shuffled to keep the current clustering of instructions.
Approved-By: Tom Tromey <tom@tromey.com>
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This commit adds recording support for the AVX instruction vzeroupper,
which zeroes the high bits of ymm registers 0..15. In the programmer's
manual, it is explicitly states that ymm registers 16..31 won't be
affected if present, so we only need to record the first 16 registers.
We record ymm_h registers since only the higher bits are touched, and
that reduces the memory footprint of the instruction.
This instruction is tested differently as we want to confirm we're only
saving the relevant registers, and we want to ensure we're saving
all of them, so it makes use of "maint print record-instruction" to see
exactly what was recorded.
Approved-By: Tom Tromey <tom@tromey.com>
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This commit adds support for the instructions VMOVDQU and VMOVDQA, used
to move values to/from 256 bit registers. Unfortunately, the
programmer's manual is very incomplete (if not wrong) about these
instructions, so the logic had to be reverse engineered from how gcc
actually encodes the instruction.
This commit also changes the memory regions from the test to store 256
bits, so its easier to test the instructions and that we're recording
ymm registers correctly.
Approved-By: Tom Tromey <tom@tromey.com>
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This commit adds recording support to all AVX and AVX2 instructions
of the form vpbroadcast. GDB is not yet concerned about AVX512 in
recording mode, so for now we only support the AVX2 registers and
instructions.
This commit also updates the gdb.reverse/i386-avx-reverse.exp to test
broadcast instructions.
Approved-By: Tom Tromey <tom@tromey.com>
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This commit adds support to recording instructions to unpack high
or low data from XMM registers, identified by the mnemonics in the
form: VPUNPCK [L|H] [BW|WD|DQ|QDQ].
All these instructions are encoded the exact same way, and only affect
the destination register, making them trivial to implement together.
It also updates the test gdb.reverse/i386-avx-reverse.exp to test these
new instructions. The test always uses ymm because the vpunpck
instructions overwrite the high bits, so we have to be able to record
the full ymm register, not just the output size.
Approved-By: Tom Tromey <tom@tromey.com>
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This commit adds support to the x86_64 AVX instructions vmovd and vmovq.
The programmers manuals for Intel and AMD describe these 2 instructions
as being almost the same, but my local testing, using gcc 13.2 on Fedora
39, showed several differences and inconsistencies.
The instruction is supposed to always use the 3-byte VEX prefix, but I
could only find 2-byte versions. The instructions aren't differentiated
by the VEX.w bit, but by opcodes and VEX.pp.
This patch adds a test with many different uses for both vmovd and
vmovq. It also updates the test gdb.reverse/step-precsave.exp to
reference the generic "missing avx support" bug open in the bug tracker
(17346), instead of pointing to one that specifically calls out to
vmovd instructions.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=23188
Approved-By: Tom Tromey <tom@tromey.com>
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This patch introduces the information needed to properly identify the
VEX prefix, used to signal an AVX and AVX2 instruction, and introduces
a helper function to handle all AVX instruction, instead of adding to
the 3000 line long recording function.
This new function will temporarily set the current thread as "not
executing" so that it can read from pseudo registers as we record, since
most AVX/AVX2 instructions would benefit from recording ymm registers.
The new helper also handles unsupported instructions so that the largest
part of the i386_process_record doesn't have to be shifted by 2 spaces,
which made an unreadably big patch file.
The only expected difference to the end user added by this patch is a
small change to the unsupported message. This patch also updates the
test gdb.reverse/step-precsave.exp, by recognizing the new output.
As a note for the future, we don't handle xmm16-31 and ymm16-31 because
those require the EVEX prefix, meaning avx512 support.
Approved-By: Tom Tromey <tom@tromey.com>
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I ran the testsuite in an environment simulating a stressed system in
combination with check-read1. This exposes a few more FAILs.
Fix some by using gdb_test_lines, as well as related gdb_get_lines.
Tested on x86_64-linux.
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Fix the following common misspellings:
...
accidently -> accidentally
additonal -> additional
addresing -> addressing
adress -> address
agaisnt -> against
albiet -> albeit
arbitary -> arbitrary
artifical -> artificial
auxillary -> auxiliary
auxilliary -> auxiliary
bcak -> back
begining -> beginning
cannonical -> canonical
compatiblity -> compatibility
completetion -> completion
diferent -> different
emited -> emitted
emiting -> emitting
emmitted -> emitted
everytime -> every time
excercise -> exercise
existance -> existence
fucntion -> function
funtion -> function
guarentee -> guarantee
htis -> this
immediatly -> immediately
layed -> laid
noone -> no one
occurances -> occurrences
occured -> occurred
originaly -> originally
preceeded -> preceded
preceeds -> precedes
propogate -> propagate
publically -> publicly
refering -> referring
substract -> subtract
substracting -> subtracting
substraction -> subtraction
taht -> that
targetting -> targeting
teh -> the
thier -> their
thru -> through
transfered -> transferred
transfering -> transferring
upto -> up to
vincinity -> vicinity
whcih -> which
whereever -> wherever
wierd -> weird
withing -> within
writen -> written
wtih -> with
doesnt -> doesn't
...
Tested on x86_64-linux.
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Fix a few typos.
unconditionaly -> unconditionally
gratuitiously -> gratuitously
configureable -> configurable
represention -> representation
distiguished -> distinguished
breakpointer -> breakpoint
asssignments -> assignments
architectual -> architectural
compatibity -> compatibility
adjustement -> adjustment
unexcepted -> unexpected
propogated -> propagated
consistant -> consistent
succeding -> succeeding
higlight -> highlight
detachs -> detach
Tested by rebuilding on x86_64-linux.
Approved-By: Simon Marchi <simon.marchi@efficios.com>
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In a record session, when we move backward, GDB switches from normal
execution to simulation. Moving forward again, the emulation continues
until the end of the reverse history. When the end is reached, the
execution stops, and a warning message is shown. This message has been
modified to indicate that the forward emulation has reached the end, but
the execution can continue as normal, and the recording will also continue.
Before this patch, the warning message shown in that case was the same as
in the reverse case. This meant that when the end of history was reached in
either backward or forward emulation, the same message was displayed:
"No more reverse-execution history."
This message has changed for these two cases. Backward emulation:
"Reached end of recorded history; stopping.
Backward execution from here not possible."
Forward emulation:
"Reached end of recorded history; stopping.
Following forward execution will be added to history."
The reason for this change is that the initial message was deceiving, for
the forward case, making the user believe that forward debugging could not
continue.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31224
Reviewed-By: Markus T. Metzger <markus.t.metzger@intel.com> (btrace)
Approved-By: Guinevere Larsen <blarsen@redhat.com>
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Currently you get this assertion failure if you try to execute the
inferior after loading a saved recording, when no recording was done
earlier in the same gdb session:
```
$ gdb -q c -ex "record restore test.rec"
Reading symbols from c...
[New LWP 26428]
Core was generated by `/tmp/c'.
Restored records from core file /tmp/test.rec.
(gdb) c
Continuing.
../../gdb/inferior.c:293: internal-error: inferior* find_inferior_pid(process_stratum_target*, int): Assertion `pid != 0' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
```
The change in step-precsave.exp triggers this bug, since now the
recording is loaded in a new gdb session, where
record_full_resume_ptid was never set.
The fix is to simply set record_full_resume_ptid when resuming a loaded
recording.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31971
Approved-By: Guinevere Larsen <blarsen@redhat.com>
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There are two kinds of MOPS instructions: set instructions and copy
instructions. Within each group there are variants with minor
differences in how they read or write to memory — e.g., non-temporal
read and/or write, unprivileged read and/or write and permutations of
those — but they work in the same way in terms of the registers and
regions of memory that they modify.
The new gdb.reverse/aarch64-mops.exp testcase verifies that MOPS
instructions are recorded and correctly reversed. Not all variants of the
copy and set instructions are tested, since there are many and the record
and replay target processes them in the same way.
PR tdep/31666
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31666
Approved-By: Luis Machado <luis.machado@arm.com>
Tested-By: Luis Machado <luis.machado@arm.com>
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This is similar to the previous patch, but for gdb_protocol_is_remote.
gdb_is_target_remote and its MI cousin mi_is_target_remote, use "maint
print target-stack", which is unnecessary when checking whether
gdb_protocol is "remote" or "extended-remote" would do. Checking
gdb_protocol is more efficient, and can be done before starting GDB
and running to main, unlike gdb_is_target_remote/mi_is_target_remote.
This adds a new gdb_protocol_is_remote procedure, and uses it in place
of gdb_is_target_remote/mi_is_target_remote throughout.
There are no uses of gdb_is_target_remote/mi_is_target_remote left
after this. Those will be eliminated in a following patch.
In some spots, we no longer need to defer the check until after
starting GDB, so the patch adjusts accordingly.
Change-Id: I90267c132f942f63426f46dbca0b77dbfdf9d2ef
Approved-By: Tom Tromey <tom@tromey.com>
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I noticed in test-case gdb.reverse/map-to-same-line.exp, that the end of main:
...
00000000004102c4 <end_of_sequence>:
4102c4: 52800000 mov w0, #0x0 // #0
4102c8: 9100c3ff add sp, sp, #0x30
4102cc: d65f03c0 ret
...
is not described by the line table:
...
File name Line number Starting address View Stmt
...
map-to-same-line.c 54 0x4102ac x
map-to-same-line.c - 0x4102c4
...
Fix this by ending the line table at $main_end.
Likewise in a few other test-cases, found using:
...
$ find gdb/testsuite/ -type f \
| xargs grep -B1 DW_LNE_end_sequence \
| grep set_address \
| egrep -v "_end|_len"
...
Tested on aarch64-linux.
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The output of "info breakpoints" includes breakpoint, watchpoint,
tracepoint, and catchpoint if they are created, so it should show
all the four types are deleted in the output of "info breakpoints"
to report empty list after "delete breakpoints".
It should also change the output of "delete breakpoints" to make it
clear that watchpoints, tracepoints, and catchpoints are also being
deleted. This is suggested by Guinevere Larsen, thank you.
$ make check-gdb TESTS="gdb.base/access-mem-running.exp"
$ gdb/gdb gdb/testsuite/outputs/gdb.base/access-mem-running/access-mem-running
[...]
(gdb) break main
Breakpoint 1 at 0x12000073c: file /home/loongson/gdb.git/gdb/testsuite/gdb.base/access-mem-running.c, line 32.
(gdb) watch global_counter
Hardware watchpoint 2: global_counter
(gdb) trace maybe_stop_here
Tracepoint 3 at 0x12000071c: file /home/loongson/gdb.git/gdb/testsuite/gdb.base/access-mem-running.c, line 27.
(gdb) catch fork
Catchpoint 4 (fork)
(gdb) info breakpoints
Num Type Disp Enb Address What
1 breakpoint keep y 0x000000012000073c in main at /home/loongson/gdb.git/gdb/testsuite/gdb.base/access-mem-running.c:32
2 hw watchpoint keep y global_counter
3 tracepoint keep y 0x000000012000071c in maybe_stop_here at /home/loongson/gdb.git/gdb/testsuite/gdb.base/access-mem-running.c:27
not installed on target
4 catchpoint keep y fork
Without this patch:
(gdb) delete breakpoints
Delete all breakpoints? (y or n) y
(gdb) info breakpoints
No breakpoints or watchpoints.
(gdb) info breakpoints 3
No breakpoint or watchpoint matching '3'.
With this patch:
(gdb) delete breakpoints
Delete all breakpoints, watchpoints, tracepoints, and catchpoints? (y or n) y
(gdb) info breakpoints
No breakpoints, watchpoints, tracepoints, or catchpoints.
(gdb) info breakpoints 3
No breakpoint, watchpoint, tracepoint, or catchpoint matching '3'.
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Approved-by: Kevin Buettner <kevinb@redhat.com>
Reviewed-By: Eli Zaretskii <eliz@gnu.org>
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I noticed in gdb.reverse/map-to-same-line.{c,exp} that the license urls are
using some kind of indirection via urldefense.proofpoint.com.
Fix this by removing this indirection.
Tested on x86_64-linux.
PR testsuite/31358
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31358
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This commit is the result of the following actions:
- Running gdb/copyright.py to update all of the copyright headers to
include 2024,
- Manually updating a few files the copyright.py script told me to
update, these files had copyright headers embedded within the
file,
- Regenerating gdbsupport/Makefile.in to refresh it's copyright
date,
- Using grep to find other files that still mentioned 2023. If
these files were updated last year from 2022 to 2023 then I've
updated them this year to 2024.
I'm sure I've probably missed some dates. Feel free to fix them up as
you spot them.
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Currently GDB when executing in reverse over multiple statements in a single
line of source code, GDB stops in the middle of the line. Thus requiring
multiple commands to reach the previous line. GDB should stop at the first
instruction of the line, not in the middle of the line.
The following description of the incorrect behavior was taken from an
earlier message by Pedro Alves <pedro@palves.net>:
https://sourceware.org/pipermail/gdb-patches/2023-January/196110.html
---------------------------------
The source line looks like:
func1 (); func2 ();
in the test case:
(gdb) list 1
1 void func1 ()
2 {
3 }
4
5 void func2 ()
6 {
7 }
8
9 int main ()
10 {
11 func1 (); func2 ();
12 }
compiled with:
$ gcc reverse.c -o reverse -g3 -O0
$ gcc -v
...
gcc version 11.3.0 (Ubuntu 11.3.0-1ubuntu1~22.04)
Now let's debug it with target record, using current gdb git master
(f3d8ae90b236),
$ gdb ~/reverse
GNU gdb (GDB) 14.0.50.20230124-git
...
Reading symbols from /home/pedro/reverse...
(gdb) start
Temporary breakpoint 1 at 0x1147: file reverse.c, line 11.
Starting program: /home/pedro/reverse
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
Temporary breakpoint 1, main () at reverse.c:11
11 func1 (); func2 ();
(gdb) record
(gdb) disassemble /s
Dump of assembler code for function main:
reverse.c:
10 {
0x000055555555513f <+0>: endbr64
0x0000555555555143 <+4>: push %rbp
0x0000555555555144 <+5>: mov %rsp,%rbp
11 func1 (); func2 ();
=> 0x0000555555555147 <+8>: mov $0x0,%eax
0x000055555555514c <+13>: call 0x555555555129 <func1>
0x0000555555555151 <+18>: mov $0x0,%eax
0x0000555555555156 <+23>: call 0x555555555134 <func2>
0x000055555555515b <+28>: mov $0x0,%eax
12 }
0x0000555555555160 <+33>: pop %rbp
0x0000555555555161 <+34>: ret
End of assembler dump.
(gdb) n
12 }
So far so good, a "next" stepped over the whole of line 11 and stopped at
line 12.
Let's confirm where we are now:
(gdb) disassemble /s
Dump of assembler code for function main:
reverse.c:
10 {
0x000055555555513f <+0>: endbr64
0x0000555555555143 <+4>: push %rbp
0x0000555555555144 <+5>: mov %rsp,%rbp
11 func1 (); func2 ();
0x0000555555555147 <+8>: mov $0x0,%eax
0x000055555555514c <+13>: call 0x555555555129 <func1>
0x0000555555555151 <+18>: mov $0x0,%eax
0x0000555555555156 <+23>: call 0x555555555134 <func2>
0x000055555555515b <+28>: mov $0x0,%eax
12 }
=> 0x0000555555555160 <+33>: pop %rbp
0x0000555555555161 <+34>: ret
End of assembler dump.
Good, we're at the first instruction of line 12.
Now let's undo the "next", with "reverse-next":
(gdb) reverse-next
11 func1 (); func2 ();
Seemingly stopped at line 11. Let's see exactly where:
(gdb) disassemble /s
Dump of assembler code for function main:
reverse.c:
10 {
0x000055555555513f <+0>: endbr64
0x0000555555555143 <+4>: push %rbp
0x0000555555555144 <+5>: mov %rsp,%rbp
11 func1 (); func2 ();
0x0000555555555147 <+8>: mov $0x0,%eax
0x000055555555514c <+13>: call 0x555555555129 <func1>
=> 0x0000555555555151 <+18>: mov $0x0,%eax
0x0000555555555156 <+23>: call 0x555555555134 <func2>
0x000055555555515b <+28>: mov $0x0,%eax
12 }
0x0000555555555160 <+33>: pop %rbp
0x0000555555555161 <+34>: ret
End of assembler dump.
(gdb)
And lo, we stopped in the middle of line 11! That is a bug, we should have
stepped back all the way to the beginning of the line. The "reverse-next"
should have fully undone the prior "next" command.
--------------------
This patch fixes the incorrect GDB behavior by ensuring that GDB stops at
the first instruction in the line.
The test case gdb.reverse/func-map-to-same-line.exp is added to testsuite
to verify this fix when the line table information is and is not available.
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When running GDB's testsuite on aarch64-linux/Ubuntu 20.04 (also spotted on
the ppc backend), there are failures in gdb.reverse/solib-precsave.exp and
gdb.reverse/solib-reverse.exp.
The failure happens around the following code:
38 b[1] = shr2(17); /* middle part two */
40 b[0] = 6; b[1] = 9; /* generic statement, end part two */
42 shr1 ("message 1\n"); /* shr1 one */
Normal execution:
- step from line 38 will land on line 40.
- step from line 40 will land on line 42.
Reverse execution:
- step from line 42 will land on line 40.
- step from line 40 will land on line 40.
- step from line 40 will land on line 38.
The problem here is that line 40 contains two contiguous but distinct
PC ranges in the line table, like so:
Line 40 - [0x7ec ~ 0x7f4]
Line 40 - [0x7f4 ~ 0x7fc]
The two distinct ranges are generated because GCC started outputting source
column information, which GDB doesn't take into account at the moment.
When stepping forward from line 40, we skip both of these ranges and land on
line 42. When stepping backward from line 42, we stop at the start PC of the
second (or first, going backwards) range of line 40.
Since we've reached ecs->event_thread->control.step_range_start, we stop
stepping backwards.
The above issues were fixed by introducing a new function that looks for
adjacent PC ranges for the same line, until we notice a line change. Then
we take that as the start PC of the range. The new start PC for the range
is used for the control.step_range_start when setting up a step range.
The test case gdb.reverse/map-to-same-line.exp is added to test the fix
for the above reverse step issues.
Patch has been tested on PowerPC, X86 and AArch64 with no regressions.
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This patch adds support for process recording of the instruction rdtscp in
x86 architecture.
Debugging applications with "record full" fail to record with the error
message "Process record does not support instruction 0xf01f9".
Approved-by: Guinevere Larsen <blarsen@redhat.com>
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Changes introduced by commit 9e8915c6cee5c37637521b424d723e990e06d597
caused a regression that meant hardware watchpoint stops would not
trigger in reverse execution or replay mode. This was documented in
PR breakpoints/21969.
The problem is that record_check_stopped_by_breakpoint always overwrites
record_full_stop_reason, thus loosing the TARGET_STOPPED_BY_WATCHPOINT
value which would be checked afterwards.
This commit fixes that by not overwriting the stop-reason in
record_full_stop_reason if we're not stopped at a breakpoint.
And the test for hw watchpoints in gdb.reverse/watch-reverse.exp actually
tested sw watchpoints again, since "set can-use-hw-watchpoints 1"
doesn't convert enabled watchpoints to use hardware.
This is fixed by disabling said watchpoint while enabling hw watchpoints.
The same is not done for gdb.reverse/watch-precsave.exp, since it's not
possible to use hw watchpoints in restored recordings anyways.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=21969
Approved-by: Guinevere Larsen <blarsen@redhat.com>
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Currently, when GDB is reverse stepping out of a function into the same
function due to a recursive call, it doesn't print frame information, as
reported by PR record/29178. This happens because when the inferior
leaves the current frame, GDB decides to refresh the step information,
clobbering the original step_frame_id, making it impossible to figure
out later on that the frame has been changed.
This commit changes GDB so that, if we notice we're in this exact
situation, we won't refresh the step information.
Because of implementation details, this change can cause some debug
information to be read when it normally wouldn't before, which showed up
as a regression on gdb.dwarf2/dw2-out-of-range-end-of-seq. Since that
isn't a problem, the test was changed to allow for the new output.
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=29178
Approved-By: Tom Tromey <tom@tromey.com>
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gdb.reverse/step-precsave.exp
When running this test on a processor that supports AVX512 (AMD EPYC
9634) on Debian 12 bookwork (system compiler is gcc 12.2.0), I see:
continue^M
Continuing.^M
Process record does not support instruction bound.^M
Process record does not support instruction 0x62 at address 0x7ffff7f49b40.^M
Process record: failed to record execution log.^M
^M
Program stopped.^M
0x00007ffff7f49b40 in ?? () from /lib/x86_64-linux-gnu/libc.so.6^M
(gdb) FAIL: gdb.reverse/step-precsave.exp: run to end of main
The instruction at this address is:
0x00007ffff7f49b40: 62 e2 7d 48 7a c6 vpbroadcastb %esi,%zmm16
This seems like an AVX512 instruction (given the use of zmm16). Match
this byte value in order to produce a KFAIL.
Change-Id: I1d20357fa538ba60b9c537160acf511a37d751ee
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30807
Approved-By: Tom Tromey <tom@tromey.com>
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When running test-case gdb.reverse/getrandom.exp on a system with eglibc 2.19,
we run into:
...
gdb compile failed, gdb.reverse/getrandom.c:18:24: fatal error: \
sys/random.h: No such file or directory
#include <sys/random.h>
^
compilation terminated.
=== gdb Summary ===
# of untested testcases 1
...
and:
...
UNTESTED: gdb.reverse/getrandom.exp: failed to prepare
...
Fix this by testing for the presence of the header, such that we have instead:
...
UNSUPPORTED: gdb.reverse/getrandom.exp: require failed: \
have_system_header sys/random.h
...
Tested on x86_64-linux and i686-linux.
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This commits tackles 2 problems in the test
gdb.reverse/insn-reverse.exp. They are, broadly: flawed logic when an
unexpected error occurs, and badly formed asm expressions.
For the first, what happens is that if the inferior stops progressing
for some reason, the test will emit an UNSUPPORTED and continue testing
by reversing from the current location and checking all registers for
every instruction. However, due to how the outputs are indexed in the
test, this early exit will cause most of the subsequent tests to be
de-synced and will emit many unrelated failures.
This commit changes the UNSUPPORTED for a FAIL, since the test has in
fact failed to record the execution of the whole function, and
decrements the recorded instruction count by one so that the indexes are
in sync once more.
At the time of committing, this reduces the amount of failures when
testing with clang-15 from around 150 to 2, and correctly identifies
where the issue lies.
The second problem is in how the asm statements in the *-x86.c file
are written. As an example, let's examine the following line:
__asm__ volatile ("rdrand %%ebp;" : "=r" (number));
This statement says that number is being used as the output variable,
but is not indicating which registers were clobbered so that the
compiler is able to properly output. GCC decides to just not save
anything, whereas clang assumes that the output is in %rax, and writes
it to the variable. This hid the problem that any compiler is not good
at dealing with asm statements that change the rbp register. It can be
seen more explicitly by informing gcc that rbp has been clobbered like
so:
__asm__ volatile ("rdrand %%ebp;" : "=r" (number) : : "%ebp");
This statement gets compiled into the following assembly:
rdrandl %ebp
movl %eax, -4(%rbp)
Which is clearly using the incorrect rbp to find the memory location of
the variable. Since the test only exercises GDB's ability to record the
register changes, this commit removes the output to memory.
Finally, correctly informing the compiler of clobbered registers
makes gcc throw an error that the rsp is no longer usable at the end of
the function. To avoid that, this commit compresses the 3 asm statements
that would save, change and reset registers into a single asm statement.
Approved-By: Tom Tromey <tom@tromey.com>
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When testing using reverse-stepi to fully step through a function, the
code checks for an infinite loop by seeing if we land on the line that
contains the return statement multiple times. This assumption only works
if there is only one instruction associated with that line, which is how
GCC handles line information, but other compilers may handle it differently.
Clang-15, for instance, associates 6. Because of this, the inferior used
to get seriously out of sync with the test expectations, and result in 13
spurious failures. The same issue occurs with gdb.reverse/step-precsave.exp.
This commit changes the test so that we check for PC instead of line
number. The test still only happens when the same line is detected, to
simplify the resulting log. With this change, no new failures are
emitted when using clang.
Approved-By: Tom Tromey <tom@tromey.com>
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The tests gdb.reverse/solib-precsave.exp and solib-reverse.exp have the
assumption that line tables will have an entry for the closing } in a
function. Not all compiles do this, one example being clang. To fix
this, this commit changes the function in shr2.c to have multiple lines,
and the test to accept either line as a correct step location.
To properly re-sync the inferiors, the function repeat_cmd_until had to
be slightly changed to work with empty "current locations", so that we
are able to step through multiple lines.
This also changes the annotations used to determine the breakpoint
locations in solib-reverse.c, adding a simple variable assignment right
before the return statement. This way GDB will not set a breakpoint in
the closing } line.
Approved-By: Tom Tromey <tom@tromey.com>
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Clang does not add line information for lines that only contain a
closing } in functions. Many tests in the gdb.reverse folder set a
breakpoint in that line, but don't seem to use information available
after the return statement is executed, so this commit moves the
breakpoint to the previous line, where the return statement is.
Approved-By: Tom Tromey <tom@tromey.com>
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This testcase sometimes gets stuck in a loop for hours when running in our
CI. The problem is that due to an issue unrelated to reverse debugging the
inferior exits early, and because of the overly generic ".*" pattern the
testcase keeps sending the "next" command without noticing that the
inferior is gone.
gdb_test_multiple has a pattern to detect that "The program is not being
run.", but since it is placed after the patterns from the caller it won't
be triggered. It also has a timeout pattern but because it is triggered
between successful matches, each time the test matches the '-re -wrap ".*"'
this counts as a successful match and the timeout is reset.
Since the test binary is compiled with debug information, fix by changing
one of the generic patterns to match entering the main function and the
other one to match the source code line number that is shown by GDB right
after the "step" command.
Also, as a precaution add a maximum number of times the "next" command will
be sent.
Co-Authored-By: Tom de Vries <tdevries@suse.de>
Reviewed-By: Bruno Larsen <blarsen@redhat.com>
Approved-By: Tom de Vries <tdevries@suse.de>
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This reverts commit 476410b3bca1389ee69e9c8fa18aaee16793a56d.
One of Simon's recent commits (2a740b3ba4c9f39c86dd75e0914ee00942cab471)
changed the way recording a remote target works and fixed the underlying
issue of the bug, so the KFails can be removed from the test.
Approved-By: Tom Tromey <tom@tromey.com>
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This commit makes two changes to how we match newline characters in
the gdb_test proc.
First, for the newline pattern between the command output and the
prompt, I propose changing from '[\r\n]+' to an explicit '\r\n'.
The old pattern would spot multiple newlines, and so there are a few
places where, as part of this commit, I've needed to add an extra
trailing '\r\n' to the pattern in the main test file, where GDB's
output actually includes a blank line.
But I think this is a good thing. If a command produces a blank line
then we should be checking for it, the current gdb_test doesn't do
that. But also, with the current gdb_test, if a blank line suddenly
appears in the output, this is going to be silently ignored, and I
think this is wrong, the test should fail in that case.
Additionally, the existing pattern will happily match a partial
newline. There are a strangely large number of tests that end with a
random '.' character. Not matching a literal period, but matching any
single character, this is then matching half of the trailing newline
sequence, while the \[\r\n\]+ in gdb_test is matching the other half
of the sequence. I can think of no reason why this would be
intentional, I suspect that the expected output at one time included a
period, which has since been remove, but I haven't bothered to check
on this. In this commit I've removed all these unneeded trailing '.'
characters.
The basic rule of gdb_test after this is that the expected pattern
needs to match everything up to, but not including the newline
sequence immediately before the GDB prompt. This is generally how the
proc is used anyway, so in almost all cases, this commit represents no
significant change.
Second, while I was cleaning up newline matching in gdb_test, I've
also removed the '[\r\n]*' that was added to the start of the pattern
passed to gdb_test_multiple.
The addition of this pattern adds no value. If the user pattern
matches at the start of a line then this would match against the
newline sequence. But, due to the '*', if the user pattern doesn't
match at the start of a line then this group doesn't care, it'll
happily match nothing.
As such, there's no value to it, it just adds more complexity for no
gain, so I'm removing it. No tests will need updating as a
consequence of this part of the patch.
Reviewed-By: Tom Tromey <tom@tromey.com>
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gdb.reverse/finish-reverse.exp
PPC64 multiple entry points, a normal entry point and an alternate entry
point. The alternate entry point is to setup the Table of Contents (TOC)
register before continuing at the normal entry point. When the TOC is
already valid, the normal entry point is used, this is typically the case.
The alternate entry point is typically referred to as the global entry
point (GEP) in IBM. The normal entry point is typically referred to as
the local entry point (LEP).
When GDB is executing the finish command in reverse, the function
finish_backward currently sets the break point at the alternate entry point.
This issue is if the function, when executing in the forward direction,
entered the function via the normal entry point, execution in the reverse
direction will never sees the break point at the alternate entry point. In
this case, the reverse execution continues until the next break point is
encountered thus stopping at the wrong place.
This patch adds a new address to struct execution_control_state to hold the
address of the alternate entry point (GEP). The finish_backwards function
is updated, if the stopping point is between the normal entry point (LEP)
and the end of the function, a breakpoint is set at the normal entry point.
If the stopping point is between the entry points, a breakpoint is set at
the alternate entry point. This ensures that GDB will always stop at the
normal entry point. If the function did enter via the alternate entry
point, GDB will detect that and continue to execute backwards in the
function until the alternate entry point is reached.
The patch fixes the behavior of the reverse-finish command on PowerPC to
match the behavior of the command on other platforms, specifically X86.
The patch does not change the behavior of the command on X86.
A new test is added to verify the reverse-finish command on PowerPC
correctly stops at the instruction where the function call is made.
The patch fixes 11 regression errors in test gdb.reverse/finish-precsave.exp
and 11 regression errors in test gdb.reverse/finish-reverse.exp.
The patch has been tested on Power 10 and X86 processor with no new
regression failures.
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Procedure step_until from test gdb.reverse/step-indirect-call-thunk.exp
is moved to lib/gdb.exp and renamed repeat_cmd_until. The existing procedure
gdb_step_until in lib/gdb.exp is simpler variant of the new repeat_cmd_until
procedure. The existing procedure gdb_step_until is changed to just call
the new repeat_cmd_until procedure with the command set to "step" and an
optional CURRENT string. The default CURRENT string is set to "\}" to work
with the existing uses of procedure gdb_step_until.
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This changes many tests to use 'require' when checking target_info.
In a few spots, the require is hoisted to the top of the file, to
avoid doing any extra work when the test is going to be skipped
anyway.
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Instead of only testing this on systems that have a SYS_time syscall,
test it everywhere using the time(2) C function, and in addition, run
the tests again using the SYS_time syscall.
The C variant ensures that if some platform uses some syscall we are
not aware of yet, we'll still exercise it, and likely fail, at which
point we should teach GDB about the syscall.
The explicit syscall variant is useful on platforms where the C
function does not call a syscall at all by default, e.g., on some
systems the C time function wraps an implementation provided by the
vDSO.
Approved-By: Tom de Vries <tdevries@suse.de>
Change-Id: Id4b755d76577d02c46b8acbfa249d9c31b587633
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gdb.reverse/step-indirect-call-thunk.exp
On aarch64-linux, I run into:
...
Running gdb.reverse/step-indirect-call-thunk.exp ...
gdb compile failed, gcc: error: unrecognized command line option \
'-mindirect-branch=thunk'; did you mean '-findirect-inlining'?
gcc: error: unrecognized command line option '-mfunction-return=thunk'; \
did you mean '-Wfunction-elimination'?
UNTESTED: gdb.reverse/step-indirect-call-thunk.exp: failed to prepare
...
Fix this by requiring istarget "x86*", similar to what was added in
gdb.base/step-indirect-call-thunk.exp by commit 43127ae5714 ("Fix
gdb.base/step-indirect-call-thunk.exp"), such that we have instead:
...
UNSUPPORTED: gdb.reverse/step-indirect-call-thunk.exp: require failed: \
istarget "x86*
...
Tested on x86_64-linux and aarch64-linux.
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