linux.git/include/linux/kgdb.h, branch v7.1-rc2

kgdb: update outdated references to kgdb_wait()

2026-04-21T15:41:54+00:00

The function kgdb_wait() was folded into the static function
kgdb_cpu_enter() by commit 62fae312197a ("kgdb: eliminate
kgdb_wait(), all cpus enter the same way").  Update the four stale
references accordingly:

 - include/linux/kgdb.h and arch/x86/kernel/kgdb.c: the
   kgdb_roundup_cpus() kdoc describes what other CPUs are rounded up
   to call.  Because kgdb_cpu_enter() is static, the correct public
   entry point is kgdb_handle_exception(); also fix a pre-existing
   grammar error ("get them be" -> "get them into") and reflow the
   text.

 - kernel/debug/debug_core.c: replace with the generic description
   "the debug trap handler", since the actual entry path is
   architecture-specific.

 - kernel/debug/gdbstub.c: kgdb_cpu_enter() is correct here (it
   describes internal state, not a call target); add the missing
   parentheses.

Suggested-by: Daniel Thompson 
Assisted-by: unnamed:deepseek-v3.2 coccinelle
Signed-off-by: Kexin Sun

kernel: debug: Add SPDX license ids to kdb files

2026-01-27T14:57:20+00:00

Add GPL-2.0 license id to some files related to kdb and kgdb,
replacing references to GPL or COPYING.

These files were introduced into the kernel in 2008 and 2010.

Signed-off-by: Tim Bird 
Signed-off-by: Greg Kroah-Hartman

Revert "kernel/debug: Mask KGDB NMI upon entry"

2025-02-14T09:05:43+00:00

This reverts commit 5a14fead07bcf4e0acc877a8d9e1d1f40a441153.

No architectures ever implemented `enable_nmi` since the later patches
in the series adding it never landed. It's been a long time. Drop it.

NOTE: this is not a clean revert due to changes in the file in the
meantime.

Signed-off-by: Douglas Anderson 
Link: https://lore.kernel.org/r/20250129082535.3.I2254953cd852f31f354456689d68b2d910de3fbe@changeid
Signed-off-by: Greg Kroah-Hartman

Revert "tty/serial: Add kgdb_nmi driver"

2025-02-14T09:05:43+00:00

This reverts commit 0c57dfcc6c1d037243c2f8fbf62eab3633326ec0.

The functionality was supoosed to be used by a later patch in the
series that never landed [1]. Drop it.

NOTE: part of functionality was already reverted by commit
39d0be87438a ("serial: kgdb_nmi: Remove unused knock code"). Also note
that this revert is not a clean revert given code changes that have
happened in the meantime.

It's obvious that nobody is using this code since the two exposed
functions (kgdb_register_nmi_console() and
kgdb_unregister_nmi_console()) are both no-ops if
"arch_kgdb_ops.enable_nmi" is not defined. No architectures define it.

[1] https://lore.kernel.org/lkml/1348522080-32629-9-git-send-email-anton.vorontsov@linaro.org/

Signed-off-by: Douglas Anderson 
Acked-by: Andy Shevchenko 
Link: URL [1]
Link: https://lore.kernel.org/r/20250129082535.1.Ia095eac1ae357f87d23e7af2206741f5d40788f1@changeid
Signed-off-by: Greg Kroah-Hartman

serial: kgdb_nmi: Remove unused knock code

2025-01-17T11:52:27+00:00

kgdb_nmi_poll_knock() has been unused since it was added in 2013 in
commit 0c57dfcc6c1d ("tty/serial: Add kgdb_nmi driver")

Remove it, the static helpers, and module parameters it used.

(The comment explaining why it might be used sounds sensible, but
it's never been wired up, perhaps it's worth doing somewhere?)

Signed-off-by: Dr. David Alan Gilbert 
Link: https://lore.kernel.org/r/20250112135759.105541-1-linux@treblig.org
Signed-off-by: Greg Kroah-Hartman

kgdb: Provide a stub kgdb_nmicallback() if !CONFIG_KGDB

2023-06-29T14:06:32+00:00

To save architectures from needing to wrap the call in #ifdefs, add a
stub no-op version of kgdb_nmicallback(), which returns 1 if it didn't
handle anything.

Reviewed-by: Daniel Thompson 
Signed-off-by: Douglas Anderson 
Link: https://lore.kernel.org/r/20230601143109.v9.6.Ia3aeac89bb6751b682237e76e5ba594318e4b1aa@changeid
Signed-off-by: Daniel Thompson

kgdb: Fix spelling mistakes

2021-06-01T09:29:21+00:00

Fix some spelling mistakes in comments:
initalization ==> initialization
detatch ==> detach
represntation ==> representation
hexidecimal ==> hexadecimal
delimeter ==> delimiter
architecure ==> architecture

Signed-off-by: Zhen Lei 
Link: https://lore.kernel.org/r/20210529110305.9446-3-thunder.leizhen@huawei.com
Signed-off-by: Daniel Thompson

kgdb: fix to kill breakpoints on initmem after boot

2021-02-26T17:41:05+00:00

Currently breakpoints in kernel .init.text section are not handled
correctly while allowing to remove them even after corresponding pages
have been freed.

Fix it via killing .init.text section breakpoints just prior to initmem
pages being freed.

Doug: "HW breakpoints aren't handled by this patch but it's probably
not such a big deal".

Link: https://lkml.kernel.org/r/20210224081652.587785-1-sumit.garg@linaro.org
Signed-off-by: Sumit Garg 
Suggested-by: Doug Anderson 
Acked-by: Doug Anderson 
Acked-by: Daniel Thompson 
Tested-by: Daniel Thompson 
Cc: Masami Hiramatsu 
Cc: Steven Rostedt (VMware) 
Cc: Jason Wessel 
Cc: Peter Zijlstra 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

kgdb: Remove kgdb_schedule_breakpoint()

2021-02-11T10:51:56+00:00

To the very best of my knowledge there has never been any in-tree
code that calls this function. It exists largely to support an
out-of-tree driver that provides kgdb-over-ethernet using the
netpoll API.

kgdboe has been out-of-tree for more than 10 years and I don't
recall any serious attempt to upstream it at any point in the last
five. At this stage it looks better to stop carrying this code in
the kernel and integrate the code into the out-of-tree driver
instead.

The long term trajectory for the kernel looks likely to include
effort to remove or reduce the use of tasklets (something that has
also been true for the last 10 years). Thus the main real reason
for this patch is to make explicit that the in-tree kgdb features
do not require tasklets.

Signed-off-by: Daniel Thompson 
Link: https://lore.kernel.org/r/20210210142525.2876648-1-daniel.thompson@linaro.org
Reviewed-by: Douglas Anderson 
Acked-by: Davidlohr Bueso 
Acked-by: Jason Wessel

kgdb: Honour the kprobe blocklist when setting breakpoints

2020-09-28T11:14:08+00:00

Currently kgdb has absolutely no safety rails in place to discourage or
prevent a user from placing a breakpoint in dangerous places such as
the debugger's own trap entry/exit and other places where it is not safe
to take synchronous traps.

Introduce a new config symbol KGDB_HONOUR_BLOCKLIST and modify the
default implementation of kgdb_validate_break_address() so that we use
the kprobe blocklist to prohibit instrumentation of critical functions
if the config symbol is set. The config symbol dependencies are set to
ensure that the blocklist will be enabled by default if we enable KGDB
and are compiling for an architecture where we HAVE_KPROBES.

Suggested-by: Peter Zijlstra 
Reviewed-by: Douglas Anderson 
Reviewed-by: Masami Hiramatsu 
Link: https://lore.kernel.org/r/20200927211531.1380577-2-daniel.thompson@linaro.org
Signed-off-by: Daniel Thompson