diff options
Diffstat (limited to 'drivers/hv/vmbus_drv.c')
| -rw-r--r-- | drivers/hv/vmbus_drv.c | 40 |
1 files changed, 36 insertions, 4 deletions
diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index 1ed9b32853a1..b6114cc89aeb 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -39,6 +39,7 @@ #include <asm/mshyperv.h> #include <linux/notifier.h> #include <linux/ptrace.h> +#include <linux/kdebug.h> #include "hyperv_vmbus.h" static struct acpi_device *hv_acpi_dev; @@ -48,12 +49,18 @@ static struct completion probe_event; static int irq; -static int hyperv_panic_event(struct notifier_block *nb, - unsigned long event, void *ptr) +static void hyperv_report_panic(struct pt_regs *regs) { - struct pt_regs *regs; + static bool panic_reported; - regs = current_pt_regs(); + /* + * We prefer to report panic on 'die' chain as we have proper + * registers to report, but if we miss it (e.g. on BUG()) we need + * to report it on 'panic'. + */ + if (panic_reported) + return; + panic_reported = true; wrmsrl(HV_X64_MSR_CRASH_P0, regs->ip); wrmsrl(HV_X64_MSR_CRASH_P1, regs->ax); @@ -65,9 +72,32 @@ static int hyperv_panic_event(struct notifier_block *nb, * Let Hyper-V know there is crash data available */ wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY); +} + +static int hyperv_panic_event(struct notifier_block *nb, unsigned long val, + void *args) +{ + struct pt_regs *regs; + + regs = current_pt_regs(); + + hyperv_report_panic(regs); return NOTIFY_DONE; } +static int hyperv_die_event(struct notifier_block *nb, unsigned long val, + void *args) +{ + struct die_args *die = (struct die_args *)args; + struct pt_regs *regs = die->regs; + + hyperv_report_panic(regs); + return NOTIFY_DONE; +} + +static struct notifier_block hyperv_die_block = { + .notifier_call = hyperv_die_event, +}; static struct notifier_block hyperv_panic_block = { .notifier_call = hyperv_panic_event, }; @@ -842,6 +872,7 @@ static int vmbus_bus_init(int irq) * Only register if the crash MSRs are available */ if (ms_hyperv.features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { + register_die_notifier(&hyperv_die_block); atomic_notifier_chain_register(&panic_notifier_list, &hyperv_panic_block); } @@ -1139,6 +1170,7 @@ static void __exit vmbus_exit(void) tasklet_kill(&msg_dpc); vmbus_free_channels(); if (ms_hyperv.features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { + unregister_die_notifier(&hyperv_die_block); atomic_notifier_chain_unregister(&panic_notifier_list, &hyperv_panic_block); } |