From c6a7c646cb9a202ae609c7585a46217280e58114 Mon Sep 17 00:00:00 2001 From: Xiongfeng Wang Date: Sat, 20 Feb 2021 11:01:00 +0800 Subject: [PATCH] sdei_watchdog: clear EOI of the secure timer before kdump hulk inclusion category: feature bugzilla: 48046 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 Reviewed-by: Hanjun Guo Signed-off-by: Yang Yingliang Signed-off-by: Xiongfeng Wang Signed-off-by: Zheng Zengkai --- 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 a0b144cfaea7..f176def34fd9 100644 --- a/arch/arm64/kernel/machine_kexec.c +++ b/arch/arm64/kernel/machine_kexec.c @@ -10,6 +10,7 @@ #include #include #include +#include #include #include @@ -254,6 +255,15 @@ 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 2b69dd0da2e9..8f354769e4f8 100644 --- a/drivers/firmware/arm_sdei.c +++ b/drivers/firmware/arm_sdei.c @@ -197,6 +197,12 @@ 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 099b9a4e6e4c..7ca9aad9d3a5 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 a7d817b5fa84..5a4ce2eca99e 100644 --- a/include/linux/nmi.h +++ b/include/linux/nmi.h @@ -222,4 +222,10 @@ int proc_watchdog_cpumask(struct ctl_table *, int, void *, size_t *, loff_t *); #include #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 -- GitLab