From: Douglas Anderson <dianders@xxxxxxxxxxxx> [ Upstream commit 9ec272c586b07d1abf73438524bd12b1df9c5f9b ] Patch series "watchdog: Cleanup / fixes after buddy series v5 reviews". This patch series attempts to finish resolving the feedback received from Petr Mladek on the v5 series I posted. Probably the only thing that wasn't fully as clean as Petr requested was the Kconfig stuff. I couldn't find a better way to express it without a more major overhaul. In the very least, I renamed "NON_ARCH" to "PERF_OR_BUDDY" in the hopes that will make it marginally better. Nothing in this series is terribly critical and even the bugfixes are small. However, it does cleanup a few things that were pointed out in review. This patch (of 10): The permissions for the kernel.nmi_watchdog sysctl have always been set at compile time despite the fact that a watchdog can fail to probe. Let's fix this and set the permissions based on whether the hardlockup detector actually probed. Link: https://lkml.kernel.org/r/20230527014153.2793931-1-dianders@xxxxxxxxxxxx Link: https://lkml.kernel.org/r/20230526184139.1.I0d75971cc52a7283f495aac0bd5c3041aadc734e@changeid Fixes: a994a3147e4c ("watchdog/hardlockup/perf: Implement init time detection of perf") Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx> Reported-by: Petr Mladek <pmladek@xxxxxxxx> Closes: https://lore.kernel.org/r/ZHCn4hNxFpY5-9Ki@alley Reviewed-by: Petr Mladek <pmladek@xxxxxxxx> Cc: Christophe Leroy <christophe.leroy@xxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Michael Ellerman <mpe@xxxxxxxxxxxxxx> Cc: Nicholas Piggin <npiggin@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- include/linux/nmi.h | 6 ------ kernel/watchdog.c | 30 ++++++++++++++++++++---------- 2 files changed, 20 insertions(+), 16 deletions(-) diff --git a/include/linux/nmi.h b/include/linux/nmi.h index c4f58baf7ccb2..d54b9ba9c8247 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -91,12 +91,6 @@ static inline void hardlockup_detector_disable(void) {} void watchdog_hardlockup_check(struct pt_regs *regs); #endif -#if defined(CONFIG_HAVE_NMI_WATCHDOG) || defined(CONFIG_HARDLOCKUP_DETECTOR) -# define NMI_WATCHDOG_SYSCTL_PERM 0644 -#else -# define NMI_WATCHDOG_SYSCTL_PERM 0444 -#endif - #if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) extern void arch_touch_nmi_watchdog(void); extern void hardlockup_detector_perf_stop(void); diff --git a/kernel/watchdog.c b/kernel/watchdog.c index f2e991894af62..6b1754e8b6e96 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -830,15 +830,6 @@ static struct ctl_table watchdog_sysctls[] = { .extra1 = SYSCTL_ZERO, .extra2 = (void *)&sixty, }, - { - .procname = "nmi_watchdog", - .data = &watchdog_hardlockup_user_enabled, - .maxlen = sizeof(int), - .mode = NMI_WATCHDOG_SYSCTL_PERM, - .proc_handler = proc_nmi_watchdog, - .extra1 = SYSCTL_ZERO, - .extra2 = SYSCTL_ONE, - }, { .procname = "watchdog_cpumask", .data = &watchdog_cpumask_bits, @@ -902,10 +893,28 @@ static struct ctl_table watchdog_sysctls[] = { {} }; +static struct ctl_table watchdog_hardlockup_sysctl[] = { + { + .procname = "nmi_watchdog", + .data = &watchdog_hardlockup_user_enabled, + .maxlen = sizeof(int), + .mode = 0444, + .proc_handler = proc_nmi_watchdog, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + {} +}; + static void __init watchdog_sysctl_init(void) { register_sysctl_init("kernel", watchdog_sysctls); + + if (watchdog_hardlockup_available) + watchdog_hardlockup_sysctl[0].mode = 0644; + register_sysctl_init("kernel", watchdog_hardlockup_sysctl); } + #else #define watchdog_sysctl_init() do { } while (0) #endif /* CONFIG_SYSCTL */ @@ -961,6 +970,8 @@ static int __init lockup_detector_check(void) /* Make sure no work is pending. */ flush_work(&detector_work); + watchdog_sysctl_init(); + return 0; } @@ -980,5 +991,4 @@ void __init lockup_detector_init(void) allow_lockup_detector_init_retry = true; lockup_detector_setup(); - watchdog_sysctl_init(); } -- 2.39.2
