Hi Andrzej, On Fri, Jun 19, 2020 at 06:28:19PM +0200, Andrzej Pietrasiewicz wrote: > There exist machines which don't have SysRq key at all, e.g. chromebooks. > > This patch allows configuring an alternative key to act as SysRq. Devices > which declare KEY_SYSRQ in their 'keybit' bitmap continue using KEY_SYSRQ, > but other devices use the alternative SysRq key instead, by default F10. > Which key is actually used can be modified with sysrq's module parameter.
I guess you will be removing KEY_SYSRQ form all Chrome OS internal AT keyboards and external USB keyboard with Chrome OS layouts as well? Via udev keymap? I suppose this could work... Or have a per device setting as we allocate a separate handle for each input device attached to the SysRq handler. > > Signed-off-by: Andrzej Pietrasiewicz <[email protected]> > --- > drivers/tty/sysrq.c | 28 +++++++++++++++++++++++++--- > 1 file changed, 25 insertions(+), 3 deletions(-) > > diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c > index 0dc3878794fd..e1d271c84746 100644 > --- a/drivers/tty/sysrq.c > +++ b/drivers/tty/sysrq.c > @@ -604,6 +604,7 @@ EXPORT_SYMBOL(handle_sysrq); > > #ifdef CONFIG_INPUT > static int sysrq_reset_downtime_ms; > +static unsigned short alternative_sysrq_key = KEY_F10; > > /* Simple translation table for the SysRq keys */ > static const unsigned char sysrq_xlate[KEY_CNT] = > @@ -621,6 +622,7 @@ struct sysrq_state { > unsigned long key_down[BITS_TO_LONGS(KEY_CNT)]; > unsigned int alt; > unsigned int alt_use; > + unsigned short sysrq_key; > bool active; > bool need_reinject; > bool reinjecting; > @@ -770,10 +772,10 @@ static void sysrq_reinject_alt_sysrq(struct work_struct > *work) > > /* Simulate press and release of Alt + SysRq */ > input_inject_event(handle, EV_KEY, alt_code, 1); > - input_inject_event(handle, EV_KEY, KEY_SYSRQ, 1); > + input_inject_event(handle, EV_KEY, sysrq->sysrq_key, 1); > input_inject_event(handle, EV_SYN, SYN_REPORT, 1); > > - input_inject_event(handle, EV_KEY, KEY_SYSRQ, 0); > + input_inject_event(handle, EV_KEY, sysrq->sysrq_key, 0); > input_inject_event(handle, EV_KEY, alt_code, 0); > input_inject_event(handle, EV_SYN, SYN_REPORT, 1); > > @@ -805,6 +807,7 @@ static bool sysrq_handle_keypress(struct sysrq_state > *sysrq, > } > break; > > +key_sysrq: > case KEY_SYSRQ: > if (value == 1 && sysrq->alt != KEY_RESERVED) { > sysrq->active = true; > @@ -825,11 +828,15 @@ static bool sysrq_handle_keypress(struct sysrq_state > *sysrq, > * triggering print screen function. > */ > if (sysrq->active) > - clear_bit(KEY_SYSRQ, sysrq->handle.dev->key); > + clear_bit(sysrq->sysrq_key, sysrq->handle.dev->key); > > break; > > default: > + /* handle non-default sysrq key */ > + if (code == sysrq->sysrq_key) > + goto key_sysrq; > + > if (sysrq->active && value && value != 2) { > sysrq->need_reinject = false; > __handle_sysrq(sysrq_xlate[code], true); > @@ -924,6 +931,14 @@ static int sysrq_connect(struct input_handler *handler, > sysrq->handle.private = sysrq; > timer_setup(&sysrq->keyreset_timer, sysrq_do_reset, 0); > > + if (test_bit(KEY_SYSRQ, dev->keybit)) { > + sysrq->sysrq_key = KEY_SYSRQ; > + pr_info("%s: using default sysrq key [%x]\n", dev->name, > KEY_SYSRQ); > + } else { > + sysrq->sysrq_key = alternative_sysrq_key; > + pr_info("%s: Using alternative sysrq key: [%x]\n", dev->name, > sysrq->sysrq_key); > + } This is way too noisy IMO. > + > error = input_register_handle(&sysrq->handle); > if (error) { > pr_err("Failed to register input sysrq handler, error %d\n", > @@ -1032,6 +1047,13 @@ module_param_array_named(reset_seq, sysrq_reset_seq, > sysrq_reset_seq, > > module_param_named(sysrq_downtime_ms, sysrq_reset_downtime_ms, int, 0644); > > +module_param(alternative_sysrq_key, ushort, 0644); > +MODULE_PARM_DESC(alternative_sysrq_key, > + "Alternative SysRq key for input devices that don't have SysRq key. F10 > by default.\n" > + "Example\n" > + "Using F9 as SysRq:\n" > + "sysrq.alternative_sysrq_key=0x43\n"); > + > #else > > static inline void sysrq_register_handler(void) > > base-commit: 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 > -- > 2.17.1 > -- Dmitry
