The quilt patch titled
Subject: watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
has been removed from the -mm tree. Its filename was
watchdog-hardlockup-keep-kernelnmi_watchdog-sysctl-as-0444-if-probe-fails.patch
This patch was dropped because it was merged into the mm-nonmm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Douglas Anderson <dianders@xxxxxxxxxxxx>
Subject: watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
Date: Fri, 26 May 2023 18:41:31 -0700
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>
---
include/linux/nmi.h | 6 ------
kernel/watchdog.c | 30 ++++++++++++++++++++----------
2 files changed, 20 insertions(+), 16 deletions(-)
--- a/include/linux/nmi.h~watchdog-hardlockup-keep-kernelnmi_watchdog-sysctl-as-0444-if-probe-fails
+++ a/include/linux/nmi.h
@@ -95,12 +95,6 @@ void watchdog_hardlockup_check(unsigned
static inline void arch_touch_nmi_watchdog(void) { }
#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 hardlockup_detector_perf_stop(void);
extern void hardlockup_detector_perf_restart(void);
--- a/kernel/watchdog.c~watchdog-hardlockup-keep-kernelnmi_watchdog-sysctl-as-0444-if-probe-fails
+++ a/kernel/watchdog.c
@@ -881,15 +881,6 @@ static struct ctl_table watchdog_sysctls
.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,
.maxlen = NR_CPUS,
@@ -952,10 +943,28 @@ 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 */
@@ -1011,6 +1020,8 @@ static int __init lockup_detector_check(
/* Make sure no work is pending. */
flush_work(&detector_work);
+ watchdog_sysctl_init();
+
return 0;
}
@@ -1030,5 +1041,4 @@ void __init lockup_detector_init(void)
allow_lockup_detector_init_retry = true;
lockup_detector_setup();
- watchdog_sysctl_init();
}
_
Patches currently in -mm which might be from dianders@xxxxxxxxxxxx are
