kdb: fix ctrl+e/a/f/b/d/p/n broken in keyboard mode

Problem: When using kdb via keyboard it does not react to control
characters which are supported in serial mode.

Example: Chords such as ctrl+a/e

kdb: fix ctrl+e/a/f/b/d/p/n broken in keyboard mode

Problem: When using kdb via keyboard it does not react to control
characters which are supported in serial mode.

Example: Chords such as ctrl+a/e/d/p do not work in keyboard mode

Solution: Before disregarding non-printable key characters, check if they
are one of the supported control characters, I have took the control
characters from the switch case upwards in this function that translates
scan codes of arrow keys/backspace/home/.. to the control characters.

Suggested-by: Douglas Anderson <[email protected]>
Signed-off-by: Nir Lichtman <[email protected]>
Reviewed-by: Douglas Anderson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Daniel Thompson <[email protected]>

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kdb: include kdb_private.h for function prototypes

The kdb_kbd_cleanup_state() is called from another file through
the kdb_private.h file, but that is not included before the
definition, causing a W

kdb: include kdb_private.h for function prototypes

The kdb_kbd_cleanup_state() is called from another file through
the kdb_private.h file, but that is not included before the
definition, causing a W=1 warning:

kernel/debug/kdb/kdb_keyboard.c:198:6: error: no previous prototype for 'kdb_kbd_cleanup_state' [-Werror=missing-prototypes]

Signed-off-by: Arnd Bergmann <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Daniel Thompson <[email protected]>

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module: Move kdb module related code out of main kdb code

No functional change.

This patch migrates the kdb 'lsmod' command support out of main
kdb code into its own file under kernel/module. In ad

module: Move kdb module related code out of main kdb code

No functional change.

This patch migrates the kdb 'lsmod' command support out of main
kdb code into its own file under kernel/module. In addition to
the above, a minor style warning i.e. missing a blank line after
declarations, was resolved too. The new file was added to
MAINTAINERS. Finally we remove linux/module.h as it is entirely
redundant.

Reviewed-by: Daniel Thompson <[email protected]>
Acked-by: Daniel Thompson <[email protected]>
Signed-off-by: Aaron Tomlin <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>

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treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through mar

treewide: Use fallthrough pseudo-keyword

Replace the existing /* fall through */ comments and its variants with
the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary
fall-through markings when it is the case.

[1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Gustavo A. R. Silva <[email protected]>

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kdb: kdb_keyboard: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Notice that in this particular cas

kdb: kdb_keyboard: mark expected switch fall-throughs

In preparation to enabling -Wimplicit-fallthrough, mark switch cases
where we are expecting to fall through.

Notice that in this particular case, I replaced the code comments with
a proper "fall through" annotation, which is what GCC is expecting
to find.

Signed-off-by: Gustavo A. R. Silva <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]>
Signed-off-by: Daniel Thompson <[email protected]>

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KDB: Fix usability issues relating to the 'enter' key.

This fixes the following problems:
1) Typematic-repeat of 'enter' gives warning message
and leaks make/break if KDB exits. Repeats
look s

KDB: Fix usability issues relating to the 'enter' key.

This fixes the following problems:
1) Typematic-repeat of 'enter' gives warning message
and leaks make/break if KDB exits. Repeats
look something like 0x1c 0x1c .... 0x9c
2) Use of 'keypad enter' gives warning message and
leaks the ENTER break/make code out if KDB exits.
KP ENTER repeats look someting like 0xe0 0x1c
0xe0 0x1c ... 0xe0 0x9c.
3) Lag on the order of seconds between "break" and "make" when
expecting the enter "break" code. Seen under virtualized
environments such as VMware ESX.

The existing special enter handler tries to glob the enter break code,
but this fails if the other (KP) enter was used, or if there was a key
repeat. It also fails if you mashed some keys along with enter, and
you ended up with a non-enter make or non-enter break code coming
after the enter make code. So first, we modify the handler to handle
these cases. But performing these actions on every enter is annoying
since now you can't hold ENTER down to scroll <more>d messages in
KDB. Since this special behaviour is only necessary to handle the
exiting KDB ('g' + ENTER) without leaking scancodes to the OS. This
cleanup needs to get executed anytime the kdb_main loop exits.

Tested on QEMU. Set a bp on atkbd.c to verify no scan code was leaked.

Cc: Andrei Warkentin <[email protected]>
[[email protected]: move cleanup calls to kdb_main.c]
Signed-off-by: Andrei Warkentin <[email protected]>
Signed-off-by: Jason Wessel <[email protected]>

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kgdboc,keyboard: Keyboard driver for kdb with kgdb

This patch adds in the kdb PS/2 keyboard driver. This was mostly a
direct port from the original kdb where I cleaned up the code against
checkpatc

kgdboc,keyboard: Keyboard driver for kdb with kgdb

This patch adds in the kdb PS/2 keyboard driver. This was mostly a
direct port from the original kdb where I cleaned up the code against
checkpatch.pl and added the glue to stitch it into kgdb.

This patch also enables early kdb debug via kgdbwait and the keyboard.

All the access to configure kdb using either a serial console or the
keyboard is done via kgdboc.

If you want to use only the keyboard and want to break in early you
would add to your kernel command arguments:

kgdboc=kbd kgdbwait

If you wanted serial and or the keyboard access you could use:

kgdboc=kbd,ttyS0

You can also configure kgdboc as a kernel module or at run time with
the sysfs where you can activate and deactivate kgdb.

Turn it on:
echo kbd,ttyS0 > /sys/module/kgdboc/parameters/kgdboc

Turn it off:
echo "" > /sys/module/kgdboc/parameters/kgdboc

Signed-off-by: Jason Wessel <[email protected]>
Reviewed-by: Dmitry Torokhov <[email protected]>

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