From: Don Zickus Date: Tue, 26 Sep 2006 08:52:27 +0000 (+0200) Subject: [PATCH] i386/x86-64: Remove un/set_nmi_callback and reserve/release_lapic_nmi functions X-Git-Tag: v2.6.19-rc1~1077^2~213 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2fbe7b25c8edaf2d10e6c1a4cc9f8afe714c4764;p=linux-2.6 [PATCH] i386/x86-64: Remove un/set_nmi_callback and reserve/release_lapic_nmi functions Removes the un/set_nmi_callback and reserve/release_lapic_nmi functions as they are no longer needed. The various subsystems are modified to register with the die_notifier instead. Also includes compile fixes by Andrew Morton. Signed-off-by: Don Zickus Signed-off-by: Andi Kleen --- diff --git a/arch/i386/kernel/crash.c b/arch/i386/kernel/crash.c index 5b96f03836..736c76d6b3 100644 --- a/arch/i386/kernel/crash.c +++ b/arch/i386/kernel/crash.c @@ -22,6 +22,8 @@ #include #include #include +#include + #include @@ -93,9 +95,18 @@ static void crash_save_self(struct pt_regs *regs) #if defined(CONFIG_SMP) && defined(CONFIG_X86_LOCAL_APIC) static atomic_t waiting_for_crash_ipi; -static int crash_nmi_callback(struct pt_regs *regs, int cpu) +static int crash_nmi_callback(struct notifier_block *self, + unsigned long val, void *data) { + struct pt_regs *regs; struct pt_regs fixed_regs; + int cpu; + + if (val != DIE_NMI) + return NOTIFY_OK; + + regs = ((struct die_args *)data)->regs; + cpu = raw_smp_processor_id(); /* Don't do anything if this handler is invoked on crashing cpu. * Otherwise, system will completely hang. Crashing cpu can get @@ -125,13 +136,18 @@ static void smp_send_nmi_allbutself(void) send_IPI_allbutself(NMI_VECTOR); } +static struct notifier_block crash_nmi_nb = { + .notifier_call = crash_nmi_callback, +}; + static void nmi_shootdown_cpus(void) { unsigned long msecs; atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); /* Would it be better to replace the trap vector here? */ - set_nmi_callback(crash_nmi_callback); + if (register_die_notifier(&crash_nmi_nb)) + return; /* return what? */ /* Ensure the new callback function is set before sending * out the NMI */ diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c index bd96ea4f29..acd3fdea2a 100644 --- a/arch/i386/kernel/nmi.c +++ b/arch/i386/kernel/nmi.c @@ -42,20 +42,6 @@ static DEFINE_PER_CPU(unsigned long, evntsel_nmi_owner[3]); */ #define NMI_MAX_COUNTER_BITS 66 -/* - * lapic_nmi_owner tracks the ownership of the lapic NMI hardware: - * - it may be reserved by some other driver, or not - * - when not reserved by some other driver, it may be used for - * the NMI watchdog, or not - * - * This is maintained separately from nmi_active because the NMI - * watchdog may also be driven from the I/O APIC timer. - */ -static DEFINE_SPINLOCK(lapic_nmi_owner_lock); -static unsigned int lapic_nmi_owner; -#define LAPIC_NMI_WATCHDOG (1<<0) -#define LAPIC_NMI_RESERVED (1<<1) - /* nmi_active: * >0: the lapic NMI watchdog is active, but can be disabled * <0: the lapic NMI watchdog has not been set up, and cannot @@ -325,33 +311,6 @@ static void enable_lapic_nmi_watchdog(void) touch_nmi_watchdog(); } -int reserve_lapic_nmi(void) -{ - unsigned int old_owner; - - spin_lock(&lapic_nmi_owner_lock); - old_owner = lapic_nmi_owner; - lapic_nmi_owner |= LAPIC_NMI_RESERVED; - spin_unlock(&lapic_nmi_owner_lock); - if (old_owner & LAPIC_NMI_RESERVED) - return -EBUSY; - if (old_owner & LAPIC_NMI_WATCHDOG) - disable_lapic_nmi_watchdog(); - return 0; -} - -void release_lapic_nmi(void) -{ - unsigned int new_owner; - - spin_lock(&lapic_nmi_owner_lock); - new_owner = lapic_nmi_owner & ~LAPIC_NMI_RESERVED; - lapic_nmi_owner = new_owner; - spin_unlock(&lapic_nmi_owner_lock); - if (new_owner & LAPIC_NMI_WATCHDOG) - enable_lapic_nmi_watchdog(); -} - void disable_timer_nmi_watchdog(void) { BUG_ON(nmi_watchdog != NMI_IO_APIC); @@ -866,6 +825,15 @@ done: return rc; } +int do_nmi_callback(struct pt_regs * regs, int cpu) +{ +#ifdef CONFIG_SYSCTL + if (unknown_nmi_panic) + return unknown_nmi_panic_callback(regs, cpu); +#endif + return 0; +} + #ifdef CONFIG_SYSCTL static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu) @@ -873,37 +841,8 @@ static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu) unsigned char reason = get_nmi_reason(); char buf[64]; - if (!(reason & 0xc0)) { - sprintf(buf, "NMI received for unknown reason %02x\n", reason); - die_nmi(regs, buf); - } - return 0; -} - -/* - * proc handler for /proc/sys/kernel/unknown_nmi_panic - */ -int proc_unknown_nmi_panic(ctl_table *table, int write, struct file *file, - void __user *buffer, size_t *length, loff_t *ppos) -{ - int old_state; - - old_state = unknown_nmi_panic; - proc_dointvec(table, write, file, buffer, length, ppos); - if (!!old_state == !!unknown_nmi_panic) - return 0; - - if (unknown_nmi_panic) { - if (reserve_lapic_nmi() < 0) { - unknown_nmi_panic = 0; - return -EBUSY; - } else { - set_nmi_callback(unknown_nmi_panic_callback); - } - } else { - release_lapic_nmi(); - unset_nmi_callback(); - } + sprintf(buf, "NMI received for unknown reason %02x\n", reason); + die_nmi(regs, buf); return 0; } @@ -917,7 +856,5 @@ EXPORT_SYMBOL(reserve_perfctr_nmi); EXPORT_SYMBOL(release_perfctr_nmi); EXPORT_SYMBOL(reserve_evntsel_nmi); EXPORT_SYMBOL(release_evntsel_nmi); -EXPORT_SYMBOL(reserve_lapic_nmi); -EXPORT_SYMBOL(release_lapic_nmi); EXPORT_SYMBOL(disable_timer_nmi_watchdog); EXPORT_SYMBOL(enable_timer_nmi_watchdog); diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index 282f0bd40d..7db664d0b2 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c @@ -706,13 +706,6 @@ void die_nmi (struct pt_regs *regs, const char *msg) do_exit(SIGSEGV); } -static int dummy_nmi_callback(struct pt_regs * regs, int cpu) -{ - return 0; -} - -static nmi_callback_t nmi_callback = dummy_nmi_callback; - static void default_do_nmi(struct pt_regs * regs) { unsigned char reason = 0; @@ -732,9 +725,10 @@ static void default_do_nmi(struct pt_regs * regs) */ if (nmi_watchdog_tick(regs, reason)) return; + if (!do_nmi_callback(regs, smp_processor_id())) #endif - if (!rcu_dereference(nmi_callback)(regs, smp_processor_id())) unknown_nmi_error(reason, regs); + return; } if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP) @@ -765,19 +759,6 @@ fastcall void do_nmi(struct pt_regs * regs, long error_code) nmi_exit(); } -void set_nmi_callback(nmi_callback_t callback) -{ - vmalloc_sync_all(); - rcu_assign_pointer(nmi_callback, callback); -} -EXPORT_SYMBOL_GPL(set_nmi_callback); - -void unset_nmi_callback(void) -{ - nmi_callback = dummy_nmi_callback; -} -EXPORT_SYMBOL_GPL(unset_nmi_callback); - #ifdef CONFIG_KPROBES fastcall void __kprobes do_int3(struct pt_regs *regs, long error_code) { diff --git a/arch/i386/oprofile/nmi_int.c b/arch/i386/oprofile/nmi_int.c index 8710ca081b..b3610188bc 100644 --- a/arch/i386/oprofile/nmi_int.c +++ b/arch/i386/oprofile/nmi_int.c @@ -17,14 +17,15 @@ #include #include #include +#include #include "op_counter.h" #include "op_x86_model.h" - + static struct op_x86_model_spec const * model; static struct op_msrs cpu_msrs[NR_CPUS]; static unsigned long saved_lvtpc[NR_CPUS]; - + static int nmi_start(void); static void nmi_stop(void); @@ -82,13 +83,24 @@ static void exit_driverfs(void) #define exit_driverfs() do { } while (0) #endif /* CONFIG_PM */ - -static int nmi_callback(struct pt_regs * regs, int cpu) +int profile_exceptions_notify(struct notifier_block *self, + unsigned long val, void *data) { - return model->check_ctrs(regs, &cpu_msrs[cpu]); + struct die_args *args = (struct die_args *)data; + int ret = NOTIFY_DONE; + int cpu = smp_processor_id(); + + switch(val) { + case DIE_NMI: + if (model->check_ctrs(args->regs, &cpu_msrs[cpu])) + ret = NOTIFY_STOP; + break; + default: + break; + } + return ret; } - - + static void nmi_cpu_save_registers(struct op_msrs * msrs) { unsigned int const nr_ctrs = model->num_counters; @@ -174,27 +186,29 @@ static void nmi_cpu_setup(void * dummy) apic_write(APIC_LVTPC, APIC_DM_NMI); } +static struct notifier_block profile_exceptions_nb = { + .notifier_call = profile_exceptions_notify, + .next = NULL, + .priority = 0 +}; static int nmi_setup(void) { + int err=0; + if (!allocate_msrs()) return -ENOMEM; - /* We walk a thin line between law and rape here. - * We need to be careful to install our NMI handler - * without actually triggering any NMIs as this will - * break the core code horrifically. - */ - if (reserve_lapic_nmi() < 0) { + if ((err = register_die_notifier(&profile_exceptions_nb))){ free_msrs(); - return -EBUSY; + return err; } + /* We need to serialize save and setup for HT because the subset * of msrs are distinct for save and setup operations */ on_each_cpu(nmi_save_registers, NULL, 0, 1); on_each_cpu(nmi_cpu_setup, NULL, 0, 1); - set_nmi_callback(nmi_callback); nmi_enabled = 1; return 0; } @@ -250,8 +264,7 @@ static void nmi_shutdown(void) { nmi_enabled = 0; on_each_cpu(nmi_cpu_shutdown, NULL, 0, 1); - unset_nmi_callback(); - release_lapic_nmi(); + unregister_die_notifier(&profile_exceptions_nb); free_msrs(); } diff --git a/arch/i386/oprofile/nmi_timer_int.c b/arch/i386/oprofile/nmi_timer_int.c index a33a73bb50..93ca48f804 100644 --- a/arch/i386/oprofile/nmi_timer_int.c +++ b/arch/i386/oprofile/nmi_timer_int.c @@ -17,32 +17,49 @@ #include #include #include +#include -static int nmi_timer_callback(struct pt_regs * regs, int cpu) +int profile_timer_exceptions_notify(struct notifier_block *self, + unsigned long val, void *data) { - oprofile_add_sample(regs, 0); - return 1; + struct die_args *args = (struct die_args *)data; + int ret = NOTIFY_DONE; + + switch(val) { + case DIE_NMI: + oprofile_add_sample(args->regs, 0); + ret = NOTIFY_STOP; + break; + default: + break; + } + return ret; } +static struct notifier_block profile_timer_exceptions_nb = { + .notifier_call = profile_timer_exceptions_notify, + .next = NULL, + .priority = 0 +}; + static int timer_start(void) { - disable_timer_nmi_watchdog(); - set_nmi_callback(nmi_timer_callback); + if (register_die_notifier(&profile_timer_exceptions_nb)) + return 1; return 0; } static void timer_stop(void) { - enable_timer_nmi_watchdog(); - unset_nmi_callback(); + unregister_die_notifier(&profile_timer_exceptions_nb); synchronize_sched(); /* Allow already-started NMIs to complete. */ } int __init op_nmi_timer_init(struct oprofile_operations * ops) { - if (atomic_read(&nmi_active) <= 0) + if ((nmi_watchdog != NMI_IO_APIC) || (atomic_read(&nmi_active) <= 0)) return -ENODEV; ops->start = timer_start; diff --git a/arch/x86_64/kernel/crash.c b/arch/x86_64/kernel/crash.c index d8d5750d61..44c8af6532 100644 --- a/arch/x86_64/kernel/crash.c +++ b/arch/x86_64/kernel/crash.c @@ -23,6 +23,7 @@ #include #include #include +#include /* This keeps a track of which one is crashing cpu. */ static int crashing_cpu; @@ -95,8 +96,18 @@ static void crash_save_self(struct pt_regs *regs) #ifdef CONFIG_SMP static atomic_t waiting_for_crash_ipi; -static int crash_nmi_callback(struct pt_regs *regs, int cpu) +static int crash_nmi_callback(struct notifier_block *self, + unsigned long val, void *data) { + struct pt_regs *regs; + int cpu; + + if (val != DIE_NMI) + return NOTIFY_OK; + + regs = ((struct die_args *)data)->regs; + cpu = raw_smp_processor_id(); + /* * Don't do anything if this handler is invoked on crashing cpu. * Otherwise, system will completely hang. Crashing cpu can get @@ -127,12 +138,17 @@ static void smp_send_nmi_allbutself(void) * cpu hotplug shouldn't matter. */ +static struct notifier_block crash_nmi_nb = { + .notifier_call = crash_nmi_callback, +}; + static void nmi_shootdown_cpus(void) { unsigned long msecs; atomic_set(&waiting_for_crash_ipi, num_online_cpus() - 1); - set_nmi_callback(crash_nmi_callback); + if (register_die_notifier(&crash_nmi_nb)) + return; /* return what? */ /* * Ensure the new callback function is set before sending diff --git a/arch/x86_64/kernel/nmi.c b/arch/x86_64/kernel/nmi.c index f6b881b23a..9d175dcf3a 100644 --- a/arch/x86_64/kernel/nmi.c +++ b/arch/x86_64/kernel/nmi.c @@ -41,20 +41,6 @@ static DEFINE_PER_CPU(unsigned, evntsel_nmi_owner[2]); */ #define NMI_MAX_COUNTER_BITS 66 -/* - * lapic_nmi_owner tracks the ownership of the lapic NMI hardware: - * - it may be reserved by some other driver, or not - * - when not reserved by some other driver, it may be used for - * the NMI watchdog, or not - * - * This is maintained separately from nmi_active because the NMI - * watchdog may also be driven from the I/O APIC timer. - */ -static DEFINE_SPINLOCK(lapic_nmi_owner_lock); -static unsigned int lapic_nmi_owner; -#define LAPIC_NMI_WATCHDOG (1<<0) -#define LAPIC_NMI_RESERVED (1<<1) - /* nmi_active: * >0: the lapic NMI watchdog is active, but can be disabled * <0: the lapic NMI watchdog has not been set up, and cannot @@ -321,33 +307,6 @@ static void enable_lapic_nmi_watchdog(void) touch_nmi_watchdog(); } -int reserve_lapic_nmi(void) -{ - unsigned int old_owner; - - spin_lock(&lapic_nmi_owner_lock); - old_owner = lapic_nmi_owner; - lapic_nmi_owner |= LAPIC_NMI_RESERVED; - spin_unlock(&lapic_nmi_owner_lock); - if (old_owner & LAPIC_NMI_RESERVED) - return -EBUSY; - if (old_owner & LAPIC_NMI_WATCHDOG) - disable_lapic_nmi_watchdog(); - return 0; -} - -void release_lapic_nmi(void) -{ - unsigned int new_owner; - - spin_lock(&lapic_nmi_owner_lock); - new_owner = lapic_nmi_owner & ~LAPIC_NMI_RESERVED; - lapic_nmi_owner = new_owner; - spin_unlock(&lapic_nmi_owner_lock); - if (new_owner & LAPIC_NMI_WATCHDOG) - enable_lapic_nmi_watchdog(); -} - void disable_timer_nmi_watchdog(void) { BUG_ON(nmi_watchdog != NMI_IO_APIC); @@ -762,13 +721,6 @@ done: return rc; } -static __kprobes int dummy_nmi_callback(struct pt_regs * regs, int cpu) -{ - return 0; -} - -static nmi_callback_t nmi_callback = dummy_nmi_callback; - asmlinkage __kprobes void do_nmi(struct pt_regs * regs, long error_code) { nmi_enter(); @@ -779,21 +731,12 @@ asmlinkage __kprobes void do_nmi(struct pt_regs * regs, long error_code) int do_nmi_callback(struct pt_regs * regs, int cpu) { - return rcu_dereference(nmi_callback)(regs, cpu); -} - -void set_nmi_callback(nmi_callback_t callback) -{ - vmalloc_sync_all(); - rcu_assign_pointer(nmi_callback, callback); -} -EXPORT_SYMBOL_GPL(set_nmi_callback); - -void unset_nmi_callback(void) -{ - nmi_callback = dummy_nmi_callback; +#ifdef CONFIG_SYSCTL + if (unknown_nmi_panic) + return unknown_nmi_panic_callback(regs, cpu); +#endif + return 0; } -EXPORT_SYMBOL_GPL(unset_nmi_callback); #ifdef CONFIG_SYSCTL @@ -802,37 +745,8 @@ static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu) unsigned char reason = get_nmi_reason(); char buf[64]; - if (!(reason & 0xc0)) { - sprintf(buf, "NMI received for unknown reason %02x\n", reason); - die_nmi(buf,regs); - } - return 0; -} - -/* - * proc handler for /proc/sys/kernel/unknown_nmi_panic - */ -int proc_unknown_nmi_panic(struct ctl_table *table, int write, struct file *file, - void __user *buffer, size_t *length, loff_t *ppos) -{ - int old_state; - - old_state = unknown_nmi_panic; - proc_dointvec(table, write, file, buffer, length, ppos); - if (!!old_state == !!unknown_nmi_panic) - return 0; - - if (unknown_nmi_panic) { - if (reserve_lapic_nmi() < 0) { - unknown_nmi_panic = 0; - return -EBUSY; - } else { - set_nmi_callback(unknown_nmi_panic_callback); - } - } else { - release_lapic_nmi(); - unset_nmi_callback(); - } + sprintf(buf, "NMI received for unknown reason %02x\n", reason); + die_nmi(buf,regs); return 0; } @@ -846,8 +760,6 @@ EXPORT_SYMBOL(reserve_perfctr_nmi); EXPORT_SYMBOL(release_perfctr_nmi); EXPORT_SYMBOL(reserve_evntsel_nmi); EXPORT_SYMBOL(release_evntsel_nmi); -EXPORT_SYMBOL(reserve_lapic_nmi); -EXPORT_SYMBOL(release_lapic_nmi); EXPORT_SYMBOL(disable_timer_nmi_watchdog); EXPORT_SYMBOL(enable_timer_nmi_watchdog); EXPORT_SYMBOL(touch_nmi_watchdog); diff --git a/include/asm-i386/nmi.h b/include/asm-i386/nmi.h index da0e0b4e91..34d6bf063b 100644 --- a/include/asm-i386/nmi.h +++ b/include/asm-i386/nmi.h @@ -6,24 +6,13 @@ #include -struct pt_regs; - -typedef int (*nmi_callback_t)(struct pt_regs * regs, int cpu); - -/** - * set_nmi_callback - * - * Set a handler for an NMI. Only one handler may be - * set. Return 1 if the NMI was handled. - */ -void set_nmi_callback(nmi_callback_t callback); - /** - * unset_nmi_callback + * do_nmi_callback * - * Remove the handler previously set. + * Check to see if a callback exists and execute it. Return 1 + * if the handler exists and was handled successfully. */ -void unset_nmi_callback(void); +int do_nmi_callback(struct pt_regs *regs, int cpu); extern int avail_to_resrv_perfctr_nmi_bit(unsigned int); extern int avail_to_resrv_perfctr_nmi(unsigned int); @@ -33,8 +22,6 @@ extern int reserve_evntsel_nmi(unsigned int); extern void release_evntsel_nmi(unsigned int); extern void setup_apic_nmi_watchdog (void *); -extern int reserve_lapic_nmi(void); -extern void release_lapic_nmi(void); extern void disable_timer_nmi_watchdog(void); extern void enable_timer_nmi_watchdog(void); extern int nmi_watchdog_tick (struct pt_regs * regs, unsigned reason); diff --git a/include/asm-x86_64/nmi.h b/include/asm-x86_64/nmi.h index 8f02a2a416..8818c39d34 100644 --- a/include/asm-x86_64/nmi.h +++ b/include/asm-x86_64/nmi.h @@ -7,25 +7,6 @@ #include #include -struct pt_regs; - -typedef int (*nmi_callback_t)(struct pt_regs * regs, int cpu); - -/** - * set_nmi_callback - * - * Set a handler for an NMI. Only one handler may be - * set. Return 1 if the NMI was handled. - */ -void set_nmi_callback(nmi_callback_t callback); - -/** - * unset_nmi_callback - * - * Remove the handler previously set. - */ -void unset_nmi_callback(void); - /** * do_nmi_callback * @@ -72,8 +53,6 @@ extern int reserve_evntsel_nmi(unsigned int); extern void release_evntsel_nmi(unsigned int); extern void setup_apic_nmi_watchdog (void *); -extern int reserve_lapic_nmi(void); -extern void release_lapic_nmi(void); extern void disable_timer_nmi_watchdog(void); extern void enable_timer_nmi_watchdog(void); extern int nmi_watchdog_tick (struct pt_regs * regs, unsigned reason); diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 362a0cc371..83f1683616 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -76,8 +76,6 @@ extern int compat_log; #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86) int unknown_nmi_panic; -extern int proc_unknown_nmi_panic(ctl_table *, int, struct file *, - void __user *, size_t *, loff_t *); #endif /* this is needed for the proc_dointvec_minmax for [fs_]overflow UID and GID */ @@ -628,7 +626,7 @@ static ctl_table kern_table[] = { .data = &unknown_nmi_panic, .maxlen = sizeof (int), .mode = 0644, - .proc_handler = &proc_unknown_nmi_panic, + .proc_handler = &proc_dointvec, }, #endif #if defined(CONFIG_X86)