hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7V1MG CVE: NA

-------------------------------------------------

In current code, the hardlockup detect code is contained by CONFIG_HARDLOCKUP_DETECTOR_PERF. This patch makes this code public so that other arch hardlockup detector can use it.

Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com --- include/linux/nmi.h | 15 ++++++++++--- kernel/Makefile | 2 +- kernel/watchdog_hld.c | 50 ++++++++++++++++++++++++++----------------- lib/Kconfig.debug | 2 +- 4 files changed, 44 insertions(+), 25 deletions(-)

diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 048c0b9aa623..5c4ae90c60ca 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -7,7 +7,7 @@

#include <linux/sched.h> #include <asm/irq.h> -#if defined(CONFIG_HAVE_NMI_WATCHDOG) +#if defined(CONFIG_HAVE_NMI_WATCHDOG) && !defined(CONFIG_SDEI_WATCHDOG) #include <asm/nmi.h> #endif

@@ -83,6 +83,7 @@ static inline void reset_hung_task_detector(void) { }

#if defined(CONFIG_HARDLOCKUP_DETECTOR) extern void hardlockup_detector_disable(void); +extern void watchdog_hardlockup_check(struct pt_regs *regs); extern unsigned int hardlockup_panic; #else static inline void hardlockup_detector_disable(void) {} @@ -94,8 +95,17 @@ static inline void hardlockup_detector_disable(void) {} # define NMI_WATCHDOG_SYSCTL_PERM 0444 #endif

-#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) +#if defined(CONFIG_HARDLOCKUP_DETECTOR) +#ifndef CONFIG_PPC extern void arch_touch_nmi_watchdog(void); +#endif +#else +# if !defined(CONFIG_HAVE_NMI_WATCHDOG) +static inline void arch_touch_nmi_watchdog(void) {} +# endif +#endif + +#if defined(CONFIG_HARDLOCKUP_DETECTOR_PERF) extern void hardlockup_detector_perf_stop(void); extern void hardlockup_detector_perf_restart(void); extern void hardlockup_detector_perf_disable(void); @@ -110,7 +120,6 @@ static inline void hardlockup_detector_perf_enable(void) { } static inline void hardlockup_detector_perf_cleanup(void) { } # if !defined(CONFIG_HAVE_NMI_WATCHDOG) static inline int hardlockup_detector_perf_init(void) { return -ENODEV; } -static inline void arch_touch_nmi_watchdog(void) {} # else static inline int hardlockup_detector_perf_init(void) { return 0; } # endif diff --git a/kernel/Makefile b/kernel/Makefile index b69c95315480..b354747a9747 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -91,7 +91,7 @@ obj-$(CONFIG_FAIL_FUNCTION) += fail_function.o obj-$(CONFIG_KGDB) += debug/ obj-$(CONFIG_DETECT_HUNG_TASK) += hung_task.o obj-$(CONFIG_LOCKUP_DETECTOR) += watchdog.o -obj-$(CONFIG_HARDLOCKUP_DETECTOR_PERF) += watchdog_hld.o +obj-$(CONFIG_HARDLOCKUP_DETECTOR) += watchdog_hld.o obj-$(CONFIG_SECCOMP) += seccomp.o obj-$(CONFIG_RELAY) += relay.o obj-$(CONFIG_SYSCTL) += utsname_sysctl.o diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index 247bf0b1582c..76ac86caa50f 100644 --- a/kernel/watchdog_hld.c +++ b/kernel/watchdog_hld.c @@ -22,14 +22,11 @@

static DEFINE_PER_CPU(bool, hard_watchdog_warn); static DEFINE_PER_CPU(bool, watchdog_nmi_touch); -static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); -static DEFINE_PER_CPU(struct perf_event *, dead_event); -static struct cpumask dead_events_mask;

static unsigned long hardlockup_allcpu_dumped; -static atomic_t watchdog_cpus = ATOMIC_INIT(0);

-notrace void arch_touch_nmi_watchdog(void) +#ifndef CONFIG_PPC +notrace void __weak arch_touch_nmi_watchdog(void) { /* * Using __raw here because some code paths have @@ -41,6 +38,7 @@ notrace void arch_touch_nmi_watchdog(void) raw_cpu_write(watchdog_nmi_touch, true); } EXPORT_SYMBOL(arch_touch_nmi_watchdog); +#endif

#ifdef CONFIG_HARDLOCKUP_CHECK_TIMESTAMP static DEFINE_PER_CPU(ktime_t, last_timestamp); @@ -98,22 +96,8 @@ static inline bool watchdog_check_timestamp(void) } #endif

-static struct perf_event_attr wd_hw_attr = { - .type = PERF_TYPE_HARDWARE, - .config = PERF_COUNT_HW_CPU_CYCLES, - .size = sizeof(struct perf_event_attr), - .pinned = 1, - .disabled = 1, -}; - -/* Callback function for perf event subsystem */ -static void watchdog_overflow_callback(struct perf_event *event, - struct perf_sample_data *data, - struct pt_regs *regs) +void watchdog_hardlockup_check(struct pt_regs *regs) { - /* Ensure the watchdog never gets throttled */ - event->hw.interrupts = 0; - if (__this_cpu_read(watchdog_nmi_touch) == true) { __this_cpu_write(watchdog_nmi_touch, false); return; @@ -163,6 +147,31 @@ static void watchdog_overflow_callback(struct perf_event *event, return; }

+#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF +static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); +static DEFINE_PER_CPU(struct perf_event *, dead_event); +static struct cpumask dead_events_mask; +static atomic_t watchdog_cpus = ATOMIC_INIT(0); + +static struct perf_event_attr wd_hw_attr = { + .type = PERF_TYPE_HARDWARE, + .config = PERF_COUNT_HW_CPU_CYCLES, + .size = sizeof(struct perf_event_attr), + .pinned = 1, + .disabled = 1, +}; + +/* Callback function for perf event subsystem */ +static void watchdog_overflow_callback(struct perf_event *event, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + /* Ensure the watchdog never gets throttled */ + event->hw.interrupts = 0; + + watchdog_hardlockup_check(regs); +} + static int hardlockup_detector_event_create(void) { unsigned int cpu = smp_processor_id(); @@ -294,3 +303,4 @@ int __init hardlockup_detector_perf_init(void) } return ret; } +#endif /* CONFIG_HARDLOCKUP_DETECTOR_PERF */ diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ce51d4dc6803..b8652bfdabc8 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1054,7 +1054,7 @@ config HARDLOCKUP_DETECTOR bool "Detect Hard Lockups" depends on DEBUG_KERNEL && !S390 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH - select LOCKUP_DETECTOR + select SOFTLOCKUP_DETECTOR select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF help Say Y here to enable the kernel to act as a watchdog to detect

hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7V1MG CVE: NA

-------------------------------------------------

NMI Watchdog need to enable the event for each core individually. But the existing public api 'sdei_event_enable' enable events for all cores when the event type is private.

Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com --- drivers/firmware/arm_sdei.c | 4 ++-- include/linux/arm_sdei.h | 2 ++ 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c index bac6a8993ea9..4b11136e67cf 100644 --- a/drivers/firmware/arm_sdei.c +++ b/drivers/firmware/arm_sdei.c @@ -389,7 +389,7 @@ static int sdei_platform_reset(void) return err; }

-static int sdei_api_event_enable(u32 event_num) +int sdei_api_event_enable(u32 event_num) { return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_ENABLE, event_num, 0, 0, 0, 0, NULL); @@ -436,7 +436,7 @@ int sdei_event_enable(u32 event_num) return err; }

-static int sdei_api_event_disable(u32 event_num) +int sdei_api_event_disable(u32 event_num) { return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_DISABLE, event_num, 0, 0, 0, 0, NULL); diff --git a/include/linux/arm_sdei.h b/include/linux/arm_sdei.h index 56c9f4072612..cd8ef1fc56fd 100644 --- a/include/linux/arm_sdei.h +++ b/include/linux/arm_sdei.h @@ -37,6 +37,8 @@ int sdei_event_unregister(u32 event_num); int sdei_event_enable(u32 event_num); int sdei_event_disable(u32 event_num); int sdei_api_event_interrupt_bind(int hwirq); +int sdei_api_event_disable(u32 event_num); +int sdei_api_event_enable(u32 event_num);

/* GHES register/unregister helpers */ int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb,

hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7V1MG CVE: NA

-------------------------------------------------

Add nmi_watchdog support for arm64 based on SDEI.

Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Kefeng Wang wangkefeng.wang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com

Conflicts: arch/arm64/kernel/Makefile Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com --- arch/arm64/kernel/Makefile | 1 + arch/arm64/kernel/watchdog_sdei.c | 112 ++++++++++++++++++++++++++++++ lib/Kconfig.debug | 7 ++ 3 files changed, 120 insertions(+) create mode 100644 arch/arm64/kernel/watchdog_sdei.c

diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile index 7c2bb4e72476..01af73c2db21 100644 --- a/arch/arm64/kernel/Makefile +++ b/arch/arm64/kernel/Makefile @@ -68,6 +68,7 @@ arm64-reloc-test-y := reloc_test_core.o reloc_test_syms.o obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-$(CONFIG_CRASH_CORE) += crash_core.o obj-$(CONFIG_ARM_SDE_INTERFACE) += sdei.o +obj-$(CONFIG_SDEI_WATCHDOG) += watchdog_sdei.o obj-$(CONFIG_ARM64_PTR_AUTH) += pointer_auth.o obj-$(CONFIG_ARM64_MTE) += mte.o obj-y += vdso-wrap.o diff --git a/arch/arm64/kernel/watchdog_sdei.c b/arch/arm64/kernel/watchdog_sdei.c new file mode 100644 index 000000000000..a2154aa6f27a --- /dev/null +++ b/arch/arm64/kernel/watchdog_sdei.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Detect hard lockups on a system + * + * Note: Most of this code is borrowed heavily from the perf hardlockup + * detector, so thanks to Don for the initial implementation. + */ + +#define pr_fmt(fmt) "SDEI NMI watchdog: " fmt + +#include <asm/irq_regs.h> +#include <asm/kvm_hyp.h> +#include <asm/smp_plat.h> +#include <asm/sdei.h> +#include <asm/virt.h> +#include <linux/arm_sdei.h> +#include <linux/nmi.h> + +/* We use the secure physical timer as SDEI NMI watchdog timer */ +#define SDEI_NMI_WATCHDOG_HWIRQ 29 + +static int sdei_watchdog_event_num; +static bool disable_sdei_nmi_watchdog; +static bool sdei_watchdog_registered; + +int watchdog_nmi_enable(unsigned int cpu) +{ + int ret; + + if (!sdei_watchdog_registered) + return -EINVAL; + + ret = sdei_api_event_enable(sdei_watchdog_event_num); + if (ret) { + pr_err("Enable NMI Watchdog failed on cpu%d\n", + smp_processor_id()); + return ret; + } + + return 0; +} + +void watchdog_nmi_disable(unsigned int cpu) +{ + int ret; + + if (!sdei_watchdog_registered) + return; + + ret = sdei_api_event_disable(sdei_watchdog_event_num); + if (ret) + pr_err("Disable NMI Watchdog failed on cpu%d\n", + smp_processor_id()); +} + +static int sdei_watchdog_callback(u32 event, + struct pt_regs *regs, void *arg) +{ + watchdog_hardlockup_check(regs); + + return 0; +} + +static void sdei_nmi_watchdog_bind(void *data) +{ + int ret; + + ret = sdei_api_event_interrupt_bind(SDEI_NMI_WATCHDOG_HWIRQ); + if (ret < 0) + pr_err("SDEI bind failed on cpu%d, return %d\n", + smp_processor_id(), ret); +} + +static int __init disable_sdei_nmi_watchdog_setup(char *str) +{ + disable_sdei_nmi_watchdog = true; + return 1; +} +__setup("disable_sdei_nmi_watchdog", disable_sdei_nmi_watchdog_setup); + +int __init watchdog_nmi_probe(void) +{ + int ret; + + if (disable_sdei_nmi_watchdog) + return -EINVAL; + + if (!is_hyp_mode_available()) { + pr_err("Disable SDEI NMI Watchdog in VM\n"); + return -EINVAL; + } + + sdei_watchdog_event_num = sdei_api_event_interrupt_bind(SDEI_NMI_WATCHDOG_HWIRQ); + if (sdei_watchdog_event_num < 0) { + pr_err("Bind interrupt failed. Firmware may not support SDEI !\n"); + return sdei_watchdog_event_num; + } + + on_each_cpu(sdei_nmi_watchdog_bind, NULL, true); + + ret = sdei_event_register(sdei_watchdog_event_num, + sdei_watchdog_callback, NULL); + if (ret) { + pr_err("SDEI Watchdog register callback failed\n"); + return ret; + } + + sdei_watchdog_registered = true; + pr_info("SDEI Watchdog registered successfully\n"); + + return 0; +} diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index b8652bfdabc8..5ba5438b797e 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1039,6 +1039,13 @@ config HARDLOCKUP_DETECTOR_PERF bool select SOFTLOCKUP_DETECTOR

+config SDEI_WATCHDOG + bool "SDEI NMI Watchdog support" + depends on ARM_SDE_INTERFACE + select HAVE_HARDLOCKUP_DETECTOR_ARCH + select HARDLOCKUP_CHECK_TIMESTAMP + select HARDLOCKUP_DETECTOR + # # Enables a timestamp based low pass filter to compensate for perf based # hard lockup detection which runs too fast due to turbo modes.

hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7V1MG CVE: NA

-------------------------------------------------

When we panic in hardlockup, the secure timer interrupt remains activate because firmware clear eoi after dispatch is completed. This will cause arm_arch_timer interrupt failed to trigger in the second kernel.

This patch add a new SMC helper to clear eoi of a certain interrupt and clear eoi of the secure timer before booting the second kernel.

Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com

Conflicts: include/linux/nmi.h Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com --- arch/arm64/kernel/machine_kexec.c | 10 ++++++++++ arch/arm64/kernel/watchdog_sdei.c | 6 ++++++ drivers/firmware/arm_sdei.c | 6 ++++++ include/linux/arm_sdei.h | 1 + include/linux/nmi.h | 6 ++++++ include/uapi/linux/arm_sdei.h | 1 + 6 files changed, 30 insertions(+)

diff --git a/arch/arm64/kernel/machine_kexec.c b/arch/arm64/kernel/machine_kexec.c index 078910db77a4..cfa6b0dafc88 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -10,6 +10,7 @@ #include <linux/irq.h> #include <linux/kernel.h> #include <linux/kexec.h> +#include <linux/nmi.h> #include <linux/page-flags.h> #include <linux/reboot.h> #include <linux/set_memory.h> @@ -262,6 +263,15 @@ void machine_crash_shutdown(struct pt_regs *regs) /* shutdown non-crashing cpus */ crash_smp_send_stop();

+ /* + * when we panic in hardlockup detected by sdei_watchdog, the secure + * timer interrupt remains activate here because firmware clear eoi + * after dispatch is completed. This will cause arm_arch_timer + * interrupt failed to trigger in the second kernel. So we clear eoi + * of the secure timer before booting the second kernel. + */ + sdei_watchdog_clear_eoi(); + /* for crashing cpu */ crash_save_cpu(regs, smp_processor_id()); machine_kexec_mask_interrupts(); diff --git a/arch/arm64/kernel/watchdog_sdei.c b/arch/arm64/kernel/watchdog_sdei.c index e36c4d398893..99ab9bdfdee6 100644 --- a/arch/arm64/kernel/watchdog_sdei.c +++ b/arch/arm64/kernel/watchdog_sdei.c @@ -80,6 +80,12 @@ static int __init disable_sdei_nmi_watchdog_setup(char *str) } __setup("disable_sdei_nmi_watchdog", disable_sdei_nmi_watchdog_setup);

+void sdei_watchdog_clear_eoi(void) +{ + if (sdei_watchdog_registered) + sdei_api_clear_eoi(SDEI_NMI_WATCHDOG_HWIRQ); +} + int __init watchdog_nmi_probe(void) { int ret; diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c index 4b11136e67cf..ec14c9291acb 100644 --- a/drivers/firmware/arm_sdei.c +++ b/drivers/firmware/arm_sdei.c @@ -198,6 +198,12 @@ int sdei_api_event_interrupt_bind(int hwirq) return (int)event_number; }

+int sdei_api_clear_eoi(int hwirq) +{ + return invoke_sdei_fn(SDEI_1_0_FN_SDEI_CLEAR_EOI, hwirq, 0, 0, 0, 0, + NULL); +} + static int sdei_api_event_get_info(u32 event, u32 info, u64 *result) { return invoke_sdei_fn(SDEI_1_0_FN_SDEI_EVENT_GET_INFO, event, info, 0, diff --git a/include/linux/arm_sdei.h b/include/linux/arm_sdei.h index cd8ef1fc56fd..08d39ca6b0e0 100644 --- a/include/linux/arm_sdei.h +++ b/include/linux/arm_sdei.h @@ -39,6 +39,7 @@ int sdei_event_disable(u32 event_num); int sdei_api_event_interrupt_bind(int hwirq); int sdei_api_event_disable(u32 event_num); int sdei_api_event_enable(u32 event_num); +int sdei_api_clear_eoi(int hwirq);

/* GHES register/unregister helpers */ int sdei_register_ghes(struct ghes *ghes, sdei_event_callback *normal_cb, diff --git a/include/linux/nmi.h b/include/linux/nmi.h index f6124e6ac47f..74e2c318327c 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -232,4 +232,10 @@ static inline void nmi_backtrace_stall_snap(const struct cpumask *btp) {} static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {} #endif

+#ifdef CONFIG_SDEI_WATCHDOG +void sdei_watchdog_clear_eoi(void); +#else +static inline void sdei_watchdog_clear_eoi(void) { } +#endif + #endif diff --git a/include/uapi/linux/arm_sdei.h b/include/uapi/linux/arm_sdei.h index af0630ba5437..1187b1b49c87 100644 --- a/include/uapi/linux/arm_sdei.h +++ b/include/uapi/linux/arm_sdei.h @@ -24,6 +24,7 @@ #define SDEI_1_0_FN_SDEI_INTERRUPT_RELEASE SDEI_1_0_FN(0x0E) #define SDEI_1_0_FN_SDEI_PRIVATE_RESET SDEI_1_0_FN(0x11) #define SDEI_1_0_FN_SDEI_SHARED_RESET SDEI_1_0_FN(0x12) +#define SDEI_1_0_FN_SDEI_CLEAR_EOI SDEI_1_0_FN(0x18)

#define SDEI_VERSION_MAJOR_SHIFT 48 #define SDEI_VERSION_MAJOR_MASK 0x7fff

hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7V1MG CVE: NA

-------------------------------------------------

Functions called in sdei_handler are not allowed to be kprobed, so marked them as NOKPROBE_SYMBOL. There are so many functions in 'watchdog_check_timestamp()'. Luckily, we don't need 'CONFIG_HARDLOCKUP_CHECK_TIMESTAMP' now. So just make CONFIG_SDEI_WATCHDOG depends on !CONFIG_HARDLOCKUP_CHECK_TIMESTAMP in case someone add 'CONFIG_HARDLOCKUP_CHECK_TIMESTAMP' in the future.

Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com --- arch/arm64/kernel/watchdog_sdei.c | 2 ++ kernel/watchdog.c | 2 ++ kernel/watchdog_hld.c | 2 ++ lib/Kconfig.debug | 2 +- 4 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/watchdog_sdei.c b/arch/arm64/kernel/watchdog_sdei.c index c342f86560d5..6352b589e02a 100644 --- a/arch/arm64/kernel/watchdog_sdei.c +++ b/arch/arm64/kernel/watchdog_sdei.c @@ -14,6 +14,7 @@ #include <asm/sdei.h> #include <asm/virt.h> #include <linux/arm_sdei.h> +#include <linux/kprobes.h> #include <linux/nmi.h>

/* We use the secure physical timer as SDEI NMI watchdog timer */ @@ -66,6 +67,7 @@ static int sdei_watchdog_callback(u32 event,

return 0; } +NOKPROBE_SYMBOL(sdei_watchdog_callback);

static void sdei_nmi_watchdog_bind(void *data) { diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 8e61f21e7e33..3c2f54595c32 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -16,6 +16,7 @@ #include <linux/cpu.h> #include <linux/nmi.h> #include <linux/init.h> +#include <linux/kprobes.h> #include <linux/module.h> #include <linux/sysctl.h> #include <linux/tick.h> @@ -325,6 +326,7 @@ bool is_hardlockup(void) __this_cpu_write(hrtimer_interrupts_saved, hrint); return false; } +NOKPROBE_SYMBOL(is_hardlockup);

static void watchdog_interrupt_count(void) { diff --git a/kernel/watchdog_hld.c b/kernel/watchdog_hld.c index 88f5c314a1df..a3f35067b4d0 100644 --- a/kernel/watchdog_hld.c +++ b/kernel/watchdog_hld.c @@ -14,6 +14,7 @@

#include <linux/nmi.h> #include <linux/atomic.h> +#include <linux/kprobes.h> #include <linux/module.h> #include <linux/sched/debug.h>

@@ -155,6 +156,7 @@ void watchdog_hardlockup_check(struct pt_regs *regs) __this_cpu_write(hard_watchdog_warn, false); return; } +NOKPROBE_SYMBOL(watchdog_hardlockup_check);

#ifdef CONFIG_HARDLOCKUP_DETECTOR_PERF static DEFINE_PER_CPU(struct perf_event *, watchdog_ev); diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 57832241a6ad..3165775ffcf3 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1041,7 +1041,7 @@ config HARDLOCKUP_DETECTOR_PERF

config SDEI_WATCHDOG bool "SDEI NMI Watchdog support" - depends on ARM_SDE_INTERFACE + depends on ARM_SDE_INTERFACE && !HARDLOCKUP_CHECK_TIMESTAMP select HAVE_HARDLOCKUP_DETECTOR_ARCH select HARDLOCKUP_DETECTOR

hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I7V1MG CVE: NA

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When I enable CONFIG_DEBUG_PREEMPT and CONFIG_PREEMPT on X86, I got the following Call Trace:

[ 3.341853] BUG: using smp_processor_id() in preemptible [00000000] code: swapper/0/1 [ 3.344392] caller is debug_smp_processor_id+0x17/0x20 [ 3.344395] CPU: 1 PID: 1 Comm: swapper/0 Not tainted 5.10.0+ #398 [ 3.344397] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014 [ 3.344399] Call Trace: [ 3.344410] dump_stack+0x60/0x76 [ 3.344412] check_preemption_disabled+0xba/0xc0 [ 3.344415] debug_smp_processor_id+0x17/0x20 [ 3.344422] hardlockup_detector_event_create+0xf/0x60 [ 3.344427] hardlockup_detector_perf_init+0xf/0x41 [ 3.344430] watchdog_nmi_probe+0xe/0x10 [ 3.344432] lockup_detector_init+0x22/0x5b [ 3.344437] kernel_init_freeable+0x20c/0x245 [ 3.344439] ? rest_init+0xd0/0xd0 [ 3.344441] kernel_init+0xe/0x110 [ 3.344446] ret_from_fork+0x22/0x30

It is because sched_init_smp() set 'current->nr_cpus_allowed' to possible cpu number, and check_preemption_disabled() failed. This issue is introduced by commit a79050434b45, which move down lockup_detector_init() after do_basic_setup(). Fix it by moving lockup_detector_init() to its origin place when sdei_watchdog is disabled. There is no problem when sdei_watchdog is enabled because watchdog_nmi_probe() is overridden in 'arch/arm64/kernel/watchdog_sdei.c' in this case.

Fixes: a79050434b45 ("lockup_detector: init lockup detector after all the init_calls") Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Signed-off-by: Chen Jun chenjun102@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Signed-off-by: Xiongfeng Wang wangxiongfeng2@huawei.com --- arch/arm64/kernel/watchdog_sdei.c | 2 +- include/linux/nmi.h | 2 ++ init/main.c | 6 +++++- 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/arm64/kernel/watchdog_sdei.c b/arch/arm64/kernel/watchdog_sdei.c index a499a14b23c1..75b8e034df3d 100644 --- a/arch/arm64/kernel/watchdog_sdei.c +++ b/arch/arm64/kernel/watchdog_sdei.c @@ -21,7 +21,7 @@ #define SDEI_NMI_WATCHDOG_HWIRQ 29

static int sdei_watchdog_event_num; -static bool disable_sdei_nmi_watchdog; +bool disable_sdei_nmi_watchdog; static bool sdei_watchdog_registered; static DEFINE_PER_CPU(ktime_t, last_check_time);

diff --git a/include/linux/nmi.h b/include/linux/nmi.h index 74e2c318327c..bcd770f42ee9 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -234,8 +234,10 @@ static inline void nmi_backtrace_stall_check(const struct cpumask *btp) {}

#ifdef CONFIG_SDEI_WATCHDOG void sdei_watchdog_clear_eoi(void); +extern bool disable_sdei_nmi_watchdog; #else static inline void sdei_watchdog_clear_eoi(void) { } +#define disable_sdei_nmi_watchdog 1 #endif

#endif diff --git a/init/main.c b/init/main.c index 6fe1512d272b..57e4a74652a7 100644 --- a/init/main.c +++ b/init/main.c @@ -1560,6 +1560,8 @@ static noinline void __init kernel_init_freeable(void)

rcu_init_tasks_generic(); do_pre_smp_initcalls(); + if (disable_sdei_nmi_watchdog) + lockup_detector_init();

smp_init(); sched_init_smp(); @@ -1569,7 +1571,9 @@ static noinline void __init kernel_init_freeable(void)

do_basic_setup();

- lockup_detector_init(); + /* sdei_watchdog needs to be initialized after sdei_init */ + if (!disable_sdei_nmi_watchdog) + lockup_detector_init();

kunit_run_all_tests();