From 0dc2521b233d7d2fdf61b4536fd3fbb3584e4548 Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Sat, 25 Apr 2026 20:03:39 -0400 Subject: [PATCH] um: Consolidate MAGIC_SYSRQ into generic Kconfig definition MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit kconfiglint reports: K008: config MAGIC_SYSRQ has prompts in 2 separate definitions MAGIC_SYSRQ is defined in two places with complementary conditions: arch/um/Kconfig:213 — depends on MCONSOLE (UML only) lib/Kconfig.debug:665 — depends on !UML (everything except UML) The UML definition has existed since the initial git import in commit 1da177e4c3f4 ("Linux-2.6.12-rc2"). UML needs MAGIC_SYSRQ to work through its mconsole interface rather than through keyboard input, so the UML version depends on MCONSOLE while the generic version excludes UML entirely with `depends on !UML`. These two definitions are logically complementary: on UML, MAGIC_SYSRQ requires MCONSOLE; on everything else, it has no special dependencies. This can be expressed as a single definition with `depends on !UML || MCONSOLE`, which evaluates to: - On UML: requires MCONSOLE (same as before) - On non-UML: always satisfiable (same as before) Consolidate into the generic definition in lib/Kconfig.debug by changing the dependency to `depends on !UML || MCONSOLE` and merging the UML- specific help text that explains the mconsole-based sysrq interface. Remove the now-redundant definition from arch/um/Kconfig. This follows the same unification pattern used by commit 7bd291abe2da ("sched: Unify the SCHED_{SMT,CLUSTER,MC} Kconfig") and our earlier SCHED_MC consolidation for SH. No functional change — the resulting Kconfig behavior is identical. Assisted-by: Claude:claude-opus-4-6 kconfiglint Signed-off-by: Sasha Levin Link: https://patch.msgid.link/20260426000339.57049-1-sashal@kernel.org Signed-off-by: Johannes Berg --- arch/um/Kconfig | 19 ------------------- lib/Kconfig.debug | 10 ++++++---- 2 files changed, 6 insertions(+), 23 deletions(-) diff --git a/arch/um/Kconfig b/arch/um/Kconfig index d9541d13d9eb..5af245ede463 100644 --- a/arch/um/Kconfig +++ b/arch/um/Kconfig @@ -210,25 +210,6 @@ config MCONSOLE It is safe to say 'Y' here. -config MAGIC_SYSRQ - bool "Magic SysRq key" - depends on MCONSOLE - help - If you say Y here, you will have some control over the system even - if the system crashes for example during kernel debugging (e.g., you - will be able to flush the buffer cache to disk, reboot the system - immediately or dump some status information). A key for each of the - possible requests is provided. - - This is the feature normally accomplished by pressing a key - while holding SysRq (Alt+PrintScreen). - - On UML, this is accomplished by sending a "sysrq" command with - mconsole, followed by the letter for the requested command. - - The keys are documented in . Don't say Y - unless you really know what this hack does. - config KERNEL_STACK_ORDER int "Kernel stack size order" default 2 if 64BIT diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 134b15a44625..06b63750d6aa 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -649,7 +649,7 @@ menu "Generic Kernel Debugging Instruments" config MAGIC_SYSRQ bool "Magic SysRq key" - depends on !UML + depends on !UML || MCONSOLE help If you say Y here, you will have some control over the system even if the system crashes for example during kernel debugging (e.g., you @@ -657,9 +657,11 @@ config MAGIC_SYSRQ immediately or dump some status information). This is accomplished by pressing various keys while holding SysRq (Alt+PrintScreen). It also works on a serial console (on PC hardware at least), if you - send a BREAK and then within 5 seconds a command keypress. The - keys are documented in . - Don't say Y unless you really know what this hack does. + send a BREAK and then within 5 seconds a command keypress. On UML, + this is accomplished by sending a "sysrq" command with mconsole, + followed by the letter for the requested command. The keys are + documented in . Don't say + Y unless you really know what this hack does. config MAGIC_SYSRQ_DEFAULT_ENABLE hex "Enable magic SysRq key functions by default"