[PATCH 1/2] Simplify sysrq help

[PATCH 1/2] Simplify sysrq help

[Andras Sebok]

This patch simplyfies sysrq help menu by moving each command to a 
separate line and by moving the key from brackets to after a semicolon.

before:
sysrq: HELP : loglevel(0-9) reboot(b) crash(c) terminate-all-tasks(e) memory-full-oom-kill(f) kill-all-tasks(i) thaw-filesystems(j) sak(k) show-backtrace-all-active-cpus(l) show-memory-usage(m) nice-all-RT-tasks(n) poweroff(o) show-registers(p) show-all-timers(q) unraw(r) sync(s) show-task-states(t) unmount(u) force-fb(v) show-blocked-tasks(w) dump-ftrace-buffer(z)

after:
sysrq: HELP :
loglevel : 0-9
reboot : b
crash : c
terminate-all-tasks : e
memory-full-oom-kill : f
kill-all-tasks : i
thaw-filesystems : j
sak : k
show-backtrace-all-active-cpus : l
show-memory-usage : m
nice-all-RT-tasks : n
poweroff : o
show-registers : p
show-all-timers : q
unraw : r
sync : s
show-task-states : t
unmount : u
force-fb : v
show-blocked-tasks : w
dump-ftrace-buffer : z

Signed-off-by: Andras Sebok <sebokandris2009@gmail.com>
---
 arch/alpha/kernel/setup.c       |  2 +-
 arch/loongarch/kernel/sysrq.c   |  2 +-
 arch/mips/kernel/sysrq.c        |  2 +-
 arch/powerpc/xmon/xmon.c        |  2 +-
 arch/sparc/kernel/process_64.c  |  4 +--
 drivers/gpu/drm/drm_fb_helper.c |  2 +-
 drivers/tty/sysrq.c             | 44 ++++++++++++++++-----------------
 kernel/debug/debug_core.c       |  2 +-
 kernel/power/poweroff.c         |  2 +-
 kernel/rcu/tree_stall.h         |  2 +-
 10 files changed, 32 insertions(+), 32 deletions(-)

diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
index 3d7473531ab1..d660a363fab8 100644
--- a/arch/alpha/kernel/setup.c
+++ b/arch/alpha/kernel/setup.c
@@ -428,7 +428,7 @@ static void sysrq_reboot_handler(int unused)
 
 static const struct sysrq_key_op srm_sysrq_reboot_op = {
 	.handler	= sysrq_reboot_handler,
-	.help_msg       = "reboot(b)",
+	.help_msg       = "reboot : b",
 	.action_msg     = "Resetting",
 	.enable_mask    = SYSRQ_ENABLE_BOOT,
 };
diff --git a/arch/loongarch/kernel/sysrq.c b/arch/loongarch/kernel/sysrq.c
index 366baef72d29..470a9017ca84 100644
--- a/arch/loongarch/kernel/sysrq.c
+++ b/arch/loongarch/kernel/sysrq.c
@@ -53,7 +53,7 @@ static void sysrq_handle_tlbdump(int key)
 
 static struct sysrq_key_op sysrq_tlbdump_op = {
 	.handler        = sysrq_handle_tlbdump,
-	.help_msg       = "show-tlbs(x)",
+	.help_msg       = "show-tlbs : x",
 	.action_msg     = "Show TLB entries",
 	.enable_mask	= SYSRQ_ENABLE_DUMP,
 };
diff --git a/arch/mips/kernel/sysrq.c b/arch/mips/kernel/sysrq.c
index 9c1a2019113b..ac0265a96cbe 100644
--- a/arch/mips/kernel/sysrq.c
+++ b/arch/mips/kernel/sysrq.c
@@ -54,7 +54,7 @@ static void sysrq_handle_tlbdump(int key)
 
 static const struct sysrq_key_op sysrq_tlbdump_op = {
 	.handler        = sysrq_handle_tlbdump,
-	.help_msg       = "show-tlbs(x)",
+	.help_msg       = "show-tlbs : x",
 	.action_msg     = "Show TLB entries",
 	.enable_mask	= SYSRQ_ENABLE_DUMP,
 };
diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index fae747cc57d2..bcfca6ccd8ae 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -4007,7 +4007,7 @@ static void sysrq_handle_xmon(int key)
 
 static const struct sysrq_key_op sysrq_xmon_op = {
 	.handler =	sysrq_handle_xmon,
-	.help_msg =	"xmon(x)",
+	.help_msg =	"xmon : x",
 	.action_msg =	"Entering xmon",
 };
 
diff --git a/arch/sparc/kernel/process_64.c b/arch/sparc/kernel/process_64.c
index b51d8fb0ecdc..11b85c326362 100644
--- a/arch/sparc/kernel/process_64.c
+++ b/arch/sparc/kernel/process_64.c
@@ -302,7 +302,7 @@ static void sysrq_handle_globreg(int key)
 
 static const struct sysrq_key_op sparc_globalreg_op = {
 	.handler	= sysrq_handle_globreg,
-	.help_msg	= "global-regs(y)",
+	.help_msg	= "global-regs : y",
 	.action_msg	= "Show Global CPU Regs",
 };
 
@@ -377,7 +377,7 @@ static void sysrq_handle_globpmu(int key)
 
 static const struct sysrq_key_op sparc_globalpmu_op = {
 	.handler	= sysrq_handle_globpmu,
-	.help_msg	= "global-pmu(x)",
+	.help_msg	= "global-pmu : x",
 	.action_msg	= "Show Global PMU Regs",
 };
 
diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 61a5d450cc20..105b296b17db 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -308,7 +308,7 @@ static void drm_fb_helper_sysrq(int dummy1)
 
 static const struct sysrq_key_op sysrq_drm_fb_helper_restore_op = {
 	.handler = drm_fb_helper_sysrq,
-	.help_msg = "force-fb(v)",
+	.help_msg = "force-fb : v",
 	.action_msg = "Restore framebuffer console",
 };
 #else
diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index b6e70c5cfa17..831cdadf366f 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -109,7 +109,7 @@ static void sysrq_handle_loglevel(int key)
 }
 static const struct sysrq_key_op sysrq_loglevel_op = {
 	.handler	= sysrq_handle_loglevel,
-	.help_msg	= "loglevel(0-9)",
+	.help_msg	= "loglevel : 0-9",
 	.action_msg	= "Changing Loglevel",
 	.enable_mask	= SYSRQ_ENABLE_LOG,
 };
@@ -123,7 +123,7 @@ static void sysrq_handle_SAK(int key)
 }
 static const struct sysrq_key_op sysrq_SAK_op = {
 	.handler	= sysrq_handle_SAK,
-	.help_msg	= "sak(k)",
+	.help_msg	= "sak : k",
 	.action_msg	= "SAK",
 	.enable_mask	= SYSRQ_ENABLE_KEYBOARD,
 };
@@ -139,7 +139,7 @@ static void sysrq_handle_unraw(int key)
 
 static const struct sysrq_key_op sysrq_unraw_op = {
 	.handler	= sysrq_handle_unraw,
-	.help_msg	= "unraw(r)",
+	.help_msg	= "unraw : r",
 	.action_msg	= "Keyboard mode set to system default",
 	.enable_mask	= SYSRQ_ENABLE_KEYBOARD,
 };
@@ -156,7 +156,7 @@ static void sysrq_handle_crash(int key)
 }
 static const struct sysrq_key_op sysrq_crash_op = {
 	.handler	= sysrq_handle_crash,
-	.help_msg	= "crash(c)",
+	.help_msg	= "crash : c",
 	.action_msg	= "Trigger a crash",
 	.enable_mask	= SYSRQ_ENABLE_DUMP,
 };
@@ -169,7 +169,7 @@ static void sysrq_handle_reboot(int key)
 }
 static const struct sysrq_key_op sysrq_reboot_op = {
 	.handler	= sysrq_handle_reboot,
-	.help_msg	= "reboot(b)",
+	.help_msg	= "reboot : b",
 	.action_msg	= "Resetting",
 	.enable_mask	= SYSRQ_ENABLE_BOOT,
 };
@@ -182,7 +182,7 @@ static void sysrq_handle_sync(int key)
 }
 static const struct sysrq_key_op sysrq_sync_op = {
 	.handler	= sysrq_handle_sync,
-	.help_msg	= "sync(s)",
+	.help_msg	= "sync : s",
 	.action_msg	= "Emergency Sync",
 	.enable_mask	= SYSRQ_ENABLE_SYNC,
 };
@@ -194,7 +194,7 @@ static void sysrq_handle_show_timers(int key)
 
 static const struct sysrq_key_op sysrq_show_timers_op = {
 	.handler	= sysrq_handle_show_timers,
-	.help_msg	= "show-all-timers(q)",
+	.help_msg	= "show-all-timers : q",
 	.action_msg	= "Show clockevent devices & pending hrtimers (no others)",
 };
 
@@ -204,7 +204,7 @@ static void sysrq_handle_mountro(int key)
 }
 static const struct sysrq_key_op sysrq_mountro_op = {
 	.handler	= sysrq_handle_mountro,
-	.help_msg	= "unmount(u)",
+	.help_msg	= "unmount : u",
 	.action_msg	= "Emergency Remount R/O",
 	.enable_mask	= SYSRQ_ENABLE_REMOUNT,
 };
@@ -217,7 +217,7 @@ static void sysrq_handle_showlocks(int key)
 
 static const struct sysrq_key_op sysrq_showlocks_op = {
 	.handler	= sysrq_handle_showlocks,
-	.help_msg	= "show-all-locks(d)",
+	.help_msg	= "show-all-locks : d",
 	.action_msg	= "Show Locks Held",
 };
 #else
@@ -275,7 +275,7 @@ static void sysrq_handle_showallcpus(int key)
 
 static const struct sysrq_key_op sysrq_showallcpus_op = {
 	.handler	= sysrq_handle_showallcpus,
-	.help_msg	= "show-backtrace-all-active-cpus(l)",
+	.help_msg	= "show-backtrace-all-active-cpus : l",
 	.action_msg	= "Show backtrace of all active CPUs",
 	.enable_mask	= SYSRQ_ENABLE_DUMP,
 };
@@ -295,7 +295,7 @@ static void sysrq_handle_showregs(int key)
 }
 static const struct sysrq_key_op sysrq_showregs_op = {
 	.handler	= sysrq_handle_showregs,
-	.help_msg	= "show-registers(p)",
+	.help_msg	= "show-registers : p",
 	.action_msg	= "Show Regs",
 	.enable_mask	= SYSRQ_ENABLE_DUMP,
 };
@@ -307,7 +307,7 @@ static void sysrq_handle_showstate(int key)
 }
 static const struct sysrq_key_op sysrq_showstate_op = {
 	.handler	= sysrq_handle_showstate,
-	.help_msg	= "show-task-states(t)",
+	.help_msg	= "show-task-states : t",
 	.action_msg	= "Show State",
 	.enable_mask	= SYSRQ_ENABLE_DUMP,
 };
@@ -318,7 +318,7 @@ static void sysrq_handle_showstate_blocked(int key)
 }
 static const struct sysrq_key_op sysrq_showstate_blocked_op = {
 	.handler	= sysrq_handle_showstate_blocked,
-	.help_msg	= "show-blocked-tasks(w)",
+	.help_msg	= "show-blocked-tasks : w",
 	.action_msg	= "Show Blocked State",
 	.enable_mask	= SYSRQ_ENABLE_DUMP,
 };
@@ -332,7 +332,7 @@ static void sysrq_ftrace_dump(int key)
 }
 static const struct sysrq_key_op sysrq_ftrace_dump_op = {
 	.handler	= sysrq_ftrace_dump,
-	.help_msg	= "dump-ftrace-buffer(z)",
+	.help_msg	= "dump-ftrace-buffer : z",
 	.action_msg	= "Dump ftrace buffer",
 	.enable_mask	= SYSRQ_ENABLE_DUMP,
 };
@@ -346,7 +346,7 @@ static void sysrq_handle_showmem(int key)
 }
 static const struct sysrq_key_op sysrq_showmem_op = {
 	.handler	= sysrq_handle_showmem,
-	.help_msg	= "show-memory-usage(m)",
+	.help_msg	= "show-memory-usage : m",
 	.action_msg	= "Show Memory",
 	.enable_mask	= SYSRQ_ENABLE_DUMP,
 };
@@ -377,7 +377,7 @@ static void sysrq_handle_term(int key)
 }
 static const struct sysrq_key_op sysrq_term_op = {
 	.handler	= sysrq_handle_term,
-	.help_msg	= "terminate-all-tasks(e)",
+	.help_msg	= "terminate-all-tasks : e",
 	.action_msg	= "Terminate All Tasks",
 	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
 };
@@ -407,7 +407,7 @@ static void sysrq_handle_moom(int key)
 }
 static const struct sysrq_key_op sysrq_moom_op = {
 	.handler	= sysrq_handle_moom,
-	.help_msg	= "memory-full-oom-kill(f)",
+	.help_msg	= "memory-full-oom-kill : f",
 	.action_msg	= "Manual OOM execution",
 	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
 };
@@ -419,7 +419,7 @@ static void sysrq_handle_thaw(int key)
 }
 static const struct sysrq_key_op sysrq_thaw_op = {
 	.handler	= sysrq_handle_thaw,
-	.help_msg	= "thaw-filesystems(j)",
+	.help_msg	= "thaw-filesystems : j",
 	.action_msg	= "Emergency Thaw of all frozen filesystems",
 	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
 };
@@ -434,7 +434,7 @@ static void sysrq_handle_kill(int key)
 }
 static const struct sysrq_key_op sysrq_kill_op = {
 	.handler	= sysrq_handle_kill,
-	.help_msg	= "kill-all-tasks(i)",
+	.help_msg	= "kill-all-tasks : i",
 	.action_msg	= "Kill All Tasks",
 	.enable_mask	= SYSRQ_ENABLE_SIGNAL,
 };
@@ -445,7 +445,7 @@ static void sysrq_handle_unrt(int key)
 }
 static const struct sysrq_key_op sysrq_unrt_op = {
 	.handler	= sysrq_handle_unrt,
-	.help_msg	= "nice-all-RT-tasks(n)",
+	.help_msg	= "nice-all-RT-tasks : n",
 	.action_msg	= "Nice All RT Tasks",
 	.enable_mask	= SYSRQ_ENABLE_RTNICE,
 };
@@ -605,7 +605,7 @@ void __handle_sysrq(int key, bool check_mask)
 			console_loglevel = orig_log_level;
 		}
 	} else {
-		pr_info("HELP : ");
+		pr_info("HELP : \n");
 		/* Only print the help msg once per handler */
 		for (i = 0; i < ARRAY_SIZE(sysrq_key_table); i++) {
 			if (sysrq_key_table[i]) {
@@ -617,9 +617,9 @@ void __handle_sysrq(int key, bool check_mask)
 				if (j != i)
 					continue;
 				pr_cont("%s ", sysrq_key_table[i]->help_msg);
+				pr_cont("\n");
 			}
 		}
-		pr_cont("\n");
 		console_loglevel = orig_log_level;
 	}
 	rcu_read_unlock();
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index d5e9ccde3ab8..561721e124cd 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -988,7 +988,7 @@ static void sysrq_handle_dbg(int key)
 
 static const struct sysrq_key_op sysrq_dbg_op = {
 	.handler	= sysrq_handle_dbg,
-	.help_msg	= "debug(g)",
+	.help_msg	= "debug : g",
 	.action_msg	= "DEBUG",
 };
 #endif
diff --git a/kernel/power/poweroff.c b/kernel/power/poweroff.c
index 562aa0e450ed..d9c0e6ea079a 100644
--- a/kernel/power/poweroff.c
+++ b/kernel/power/poweroff.c
@@ -31,7 +31,7 @@ static void handle_poweroff(int key)
 
 static const struct sysrq_key_op	sysrq_poweroff_op = {
 	.handler        = handle_poweroff,
-	.help_msg       = "poweroff(o)",
+	.help_msg       = "poweroff : o",
 	.action_msg     = "Power Off",
 	.enable_mask	= SYSRQ_ENABLE_BOOT,
 };
diff --git a/kernel/rcu/tree_stall.h b/kernel/rcu/tree_stall.h
index b10b8349bb2a..17a7bf7b0a2b 100644
--- a/kernel/rcu/tree_stall.h
+++ b/kernel/rcu/tree_stall.h
@@ -1042,7 +1042,7 @@ static void sysrq_show_rcu(int key)
 
 static const struct sysrq_key_op sysrq_rcudump_op = {
 	.handler = sysrq_show_rcu,
-	.help_msg = "show-rcu(y)",
+	.help_msg = "show-rcu : y",
 	.action_msg = "Show RCU tree",
 	.enable_mask = SYSRQ_ENABLE_DUMP,
 };
-- 
2.41.0

[PATCH 2/2] Add disabled text to indicate inactive commands in sysrq help menu

[Andras Sebok]

This patch adds disabled text after disabled commands in sysrq help.

before:
sak : k

after:
sak : k (disabled)

Signed-off-by: Andras Sebok <sebokandris2009@gmail.com>
---
 drivers/tty/sysrq.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/tty/sysrq.c b/drivers/tty/sysrq.c
index 831cdadf366f..1af78f76232e 100644
--- a/drivers/tty/sysrq.c
+++ b/drivers/tty/sysrq.c
@@ -617,6 +617,9 @@ void __handle_sysrq(int key, bool check_mask)
 				if (j != i)
 					continue;
 				pr_cont("%s ", sysrq_key_table[i]->help_msg);
+				if (!check_mask || (check_mask &&
+					!sysrq_on_mask(sysrq_key_table[i]->enable_mask)))
+					pr_cont("(disabled)");
 				pr_cont("\n");
 			}
 		}
-- 
2.41.0

Re: [PATCH 1/2] Simplify sysrq help

[Greg KH]

On Mon, Aug 28, 2023 at 12:27:53PM +0200, Andras Sebok wrote:
> This patch simplyfies sysrq help menu by moving each command to a 
> separate line and by moving the key from brackets to after a semicolon.
> 
> before:
> sysrq: HELP : loglevel(0-9) reboot(b) crash(c) terminate-all-tasks(e) memory-full-oom-kill(f) kill-all-tasks(i) thaw-filesystems(j) sak(k) show-backtrace-all-active-cpus(l) show-memory-usage(m) nice-all-RT-tasks(n) poweroff(o) show-registers(p) show-all-timers(q) unraw(r) sync(s) show-task-states(t) unmount(u) force-fb(v) show-blocked-tasks(w) dump-ftrace-buffer(z)
> 
> after:
> sysrq: HELP :
> loglevel : 0-9
> reboot : b
> crash : c
> terminate-all-tasks : e
> memory-full-oom-kill : f
> kill-all-tasks : i
> thaw-filesystems : j
> sak : k
> show-backtrace-all-active-cpus : l
> show-memory-usage : m
> nice-all-RT-tasks : n
> poweroff : o
> show-registers : p
> show-all-timers : q
> unraw : r
> sync : s
> show-task-states : t
> unmount : u
> force-fb : v
> show-blocked-tasks : w
> dump-ftrace-buffer : z

So now the options all scroll off the screen?  Are you sure this is
wise?  What problem are you trying to solve here, it just looks like you
are changing one "help text format for another", and doesn't actually
change much of anything.

Note the:
	sysrq: HELP :

line format being different from all the others makes this not even look
correct?

So I really do not see the point of this change here, why is it needed?

thanks,

greg k-h

Re: [PATCH 2/2] Add disabled text to indicate inactive commands in sysrq help menu

[Greg KH]

On Mon, Aug 28, 2023 at 12:27:56PM +0200, Andras Sebok wrote:
> This patch adds disabled text after disabled commands in sysrq help.
> 
> before:
> sak : k
> 
> after:
> sak : k (disabled)

No need to tease people about options they can not use :(

sorry,

greg k-h

Re: [PATCH 1/2] Simplify sysrq help

[Theodore Ts'o]

On Mon, Aug 28, 2023 at 12:51:38PM +0200, Greg KH wrote:
> So now the options all scroll off the screen?  Are you sure this is
> wise?  What problem are you trying to solve here, it just looks like you
> are changing one "help text format for another", and doesn't actually
> change much of anything.

Indeed, if you are using a VT console, this is a bad, Bad, BAD idea,
since there is very limited console scrollback, and this would blow
away a huge amount of useful information.  Maybe it might be useful
for novices who are using a serial console, but magic sysrq is
primarily used by experts, not by novices....

				- Ted