Patch series "scripts/gdb/symbols: determine KASLR offset on s390 during
early boot".
I noticed that debugging s390 early boot using the support I introduced in
commit 28939c3e99 ("scripts/gdb/symbols: determine KASLR offset on
s390") does not work.
The reason is that decompressor does not provide the vmcoreinfo note, so
KASLR offset needs to be extracted in a different way, which this series
implements. Patches 1-2 are trivial refactorings, and patch 3 is the
implementation.
This patch (of 3):
Move the code that determines the current vmlinux file into a separate
function. It will be useful later in order to analyze the kernel image in
physical memory during s390 early boot.
Link: https://lkml.kernel.org/r/20250515155811.114392-1-iii@linux.ibm.com
Link: https://lkml.kernel.org/r/20250515155811.114392-2-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "scripts/gdb: Fixes related to lx_per_cpu()".
These patches (1) fix kgdb detection on systems featuring a single CPU and
(2) update the documentation to reflect the current usage of lx_per_cpu()
and update an outdated example of its usage.
This patch (of 2):
When requested the list of threads via qfThreadInfo, gdb_cmd_query in
kernel/debug/gdbstub.c first returns "shadow" threads for CPUs followed by
the actual tasks in the system. Extended qThreadExtraInfo queries yield
"shadowCPU%d" as the name for the CPU core threads.
This behavior is used by get_gdbserver_type() to probe for KGDB by
matching the name for the thread 2 against "shadowCPU". This breaks down
on single-core systems, where thread 2 is the first nonshadow thread.
Request the name for thread 1 instead.
As GDB assigns thread IDs in the order of their appearance, it is safe to
assume shadowCPU0 at ID 1 as long as CPU0 is not hotplugged.
Before:
(gdb) info threads
Id Target Id Frame
1 Thread 4294967294 (shadowCPU0) kgdb_breakpoint ()
* 2 Thread 1 (swapper/0) kgdb_breakpoint ()
3 Thread 2 (kthreadd) 0x0000000000000000 in ?? ()
...
(gdb) p $lx_current().comm
Sorry, obtaining the current CPU is not yet supported with this gdb server.
After:
(gdb) info threads
Id Target Id Frame
1 Thread 4294967294 (shadowCPU0) kgdb_breakpoint ()
* 2 Thread 1 (swapper/0) kgdb_breakpoint ()
3 Thread 2 (kthreadd) 0x0000000000000000 in ?? ()
...
(gdb) p $lx_current().comm
$1 = "swapper/0\000\000\000\000\000\000"
Link: https://lkml.kernel.org/r/20250503123234.2407184-1-illia@yshyn.com
Link: https://lkml.kernel.org/r/20250503123234.2407184-2-illia@yshyn.com
Signed-off-by: Illia Ostapyshyn <illia@yshyn.com>
Cc: Alex Shi <alexs@kernel.org>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Dongliang Mu <dzm91@hust.edu.cn>
Cc: Florian Rommel <mail@florommel.de>
Cc: Hu Haowen <2023002089@link.tyut.edu.cn>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Yanteng Si <si.yanteng@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "scripts/gdb: Fixes for $lx_current and $lx_per_cpu".
This series fixes several bugs in the GDB scripts related to the
$lx_current and $lx_per_cpu functions. The changes were tested with GDB
10, 11, 12, 13, and 14.
Patch 1 fixes false-negative results when probing for KGDB
Patch 2 fixes the $lx_per_cpu function, which is currently non-functional
in QEMU-GDB and KGDB.
Patch 3 fixes an additional bug in $lx_per_cpu that occurs with KGDB.
Patch 4 fixes the incorrect detection of the current CPU number in KGDB,
which silently breaks $lx_per_cpu and $lx_current.
This patch (of 4):
The KGDB probe function sometimes failed to detect KGDB for SMP machines
as it assumed that task 2 (kthreadd) is running on CPU 0, which is not
necessarily the case. Now, the detection is agnostic to kthreadd's CPU.
Link: https://lkml.kernel.org/r/20240425153501.749966-1-mail@florommel.de
Link: https://lkml.kernel.org/r/20240425153501.749966-2-mail@florommel.de
Signed-off-by: Florian Rommel <mail@florommel.de>
Cc: Andrew Jones <ajones@ventanamicro.com>
Cc: Deepak Gupta <debug@rivosinc.com>
Cc: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The type atomic_long_t can have size 4 or 8 bytes, depending on
CONFIG_64BIT; it's only content, the field 'counter', is either an
int or a s64 value.
Current code incorrectly uses the fixed size utils.read_u64() to
read the field 'counter' inside atomic_long_t.
On 32 bits architectures reading the last element 'tail_id' of the
struct prb_desc_ring:
struct prb_desc_ring {
...
atomic_long_t tail_id;
};
causes the utils.read_u64() to access outside the boundary of the
struct and the gdb command 'lx-dmesg' exits with error:
Python Exception <class 'IndexError'>: index out of range
Error occurred in Python: index out of range
Query the really used atomic_long_t counter type size.
Link: https://lore.kernel.org/r/20220617143758.137307-1-antonio.borneo@foss.st.com
Fixes: e60768311a ("scripts/gdb: update for lockless printk ringbuffer")
Signed-off-by: Antonio Borneo <antonio.borneo@foss.st.com>
[pmladek@suse.com: Query the really used atomic_long_t counter type size]
Tested-by: Antonio Borneo <antonio.borneo@foss.st.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20220719122831.19890-1-pmladek@suse.com
When CONFIG_PRINTK_CALLER is set, struct printk_log contains an
additional member caller_id. This affects the offset of the log text.
Account for this by using the type information from gdb to determine all
the offsets instead of using hardcoded values.
This fixes following error:
(gdb) lx-dmesg
Python Exception <class 'ValueError'> embedded null character:
Error occurred in Python command: embedded null character
The read_u* utility functions now take an offset argument to make them
easier to use.
Link: http://lkml.kernel.org/r/20191011142500.2339-1-joel.colledge@linbit.com
Signed-off-by: Joel Colledge <joel.colledge@linbit.com>
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Kieran Bingham <kbingham@kernel.org>
Cc: Leonard Crestez <leonard.crestez@nxp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I tried to use these scripts in an ubuntu 14.04 host (gdb 7.7 compiled
against python 3.3) but there were several errors.
I believe this patch fixes these issues so that the commands now work (I
tested lx-symbols, lx-dmesg, lx-lsmod).
Main issues that needed to be resolved:
* In python 2 iterators have a "next()" method. In python 3 it is
__next__() instead (so let's just add both).
* In older python versions there was an implicit conversion
in object.__format__() (used when an object is in string.format())
where it was converting the object to str first and then
calling str's __format__(). This has now been removed so
we must explicitly convert to str the objects for which
we need to keep this behavior.
* In dmesg.py: in python 3 log_buf is now a "memoryview" object
which needs to be converted to a string in order to use string
methods like "splitlines()". Luckily memoryview exists in
python 2.7.6 as well, so we can convert log_buf to memoryview
and use the same code in both python 2 and python 3.
This version of the patch has now been tested with gdb 7.7 and both python
3.4 and python 2.7.6 (I think asking for at least python 2.7.6 is a
reasonable requirement instead of complicating the code with version
checks etc).
Signed-off-by: Pantelis Koukousoulas <pktoss@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ben Widawsky <ben@bwidawsk.net>
Cc: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
