diff --git a/arch/mips/include/asm/jump_label.h b/arch/mips/include/asm/jump_label.h index 7622ccf75076..1881b316ca45 100644 --- a/arch/mips/include/asm/jump_label.h +++ b/arch/mips/include/asm/jump_label.h @@ -20,16 +20,18 @@ #define WORD_INSN ".word" #endif -#define JUMP_LABEL(key, label) \ - do { \ - asm goto("1:\tnop\n\t" \ - "nop\n\t" \ - ".pushsection __jump_table, \"a\"\n\t" \ - WORD_INSN " 1b, %l[" #label "], %0\n\t" \ - ".popsection\n\t" \ - : : "i" (key) : : label); \ - } while (0) - +static __always_inline bool arch_static_branch(struct jump_label_key *key) +{ + asm goto("1:\tnop\n\t" + "nop\n\t" + ".pushsection __jump_table, \"aw\"\n\t" + WORD_INSN " 1b, %l[l_yes], %0\n\t" + ".popsection\n\t" + : : "i" (key) : : l_yes); + return false; +l_yes: + return true; +} #endif /* __KERNEL__ */ diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig index 2508a6f31588..4a7f14079e03 100644 --- a/arch/s390/Kconfig +++ b/arch/s390/Kconfig @@ -88,6 +88,7 @@ config S390 select HAVE_KERNEL_XZ select HAVE_GET_USER_PAGES_FAST select HAVE_ARCH_MUTEX_CPU_RELAX + select HAVE_ARCH_JUMP_LABEL if !MARCH_G5 select ARCH_INLINE_SPIN_TRYLOCK select ARCH_INLINE_SPIN_TRYLOCK_BH select ARCH_INLINE_SPIN_LOCK diff --git a/arch/s390/include/asm/jump_label.h b/arch/s390/include/asm/jump_label.h new file mode 100644 index 000000000000..95a6cf2b5b67 --- /dev/null +++ b/arch/s390/include/asm/jump_label.h @@ -0,0 +1,37 @@ +#ifndef _ASM_S390_JUMP_LABEL_H +#define _ASM_S390_JUMP_LABEL_H + +#include + +#define JUMP_LABEL_NOP_SIZE 6 + +#ifdef CONFIG_64BIT +#define ASM_PTR ".quad" +#define ASM_ALIGN ".balign 8" +#else +#define ASM_PTR ".long" +#define ASM_ALIGN ".balign 4" +#endif + +static __always_inline bool arch_static_branch(struct jump_label_key *key) +{ + asm goto("0: brcl 0,0\n" + ".pushsection __jump_table, \"aw\"\n" + ASM_ALIGN "\n" + ASM_PTR " 0b, %l[label], %0\n" + ".popsection\n" + : : "X" (key) : : label); + return false; +label: + return true; +} + +typedef unsigned long jump_label_t; + +struct jump_entry { + jump_label_t code; + jump_label_t target; + jump_label_t key; +}; + +#endif diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile index 64230bc392fa..5ff15dacb571 100644 --- a/arch/s390/kernel/Makefile +++ b/arch/s390/kernel/Makefile @@ -23,7 +23,7 @@ CFLAGS_sysinfo.o += -Iinclude/math-emu -Iarch/s390/math-emu -w obj-y := bitmap.o traps.o time.o process.o base.o early.o setup.o \ processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o \ s390_ext.o debug.o irq.o ipl.o dis.o diag.o mem_detect.o \ - vdso.o vtime.o sysinfo.o nmi.o sclp.o + vdso.o vtime.o sysinfo.o nmi.o sclp.o jump_label.o obj-y += $(if $(CONFIG_64BIT),entry64.o,entry.o) obj-y += $(if $(CONFIG_64BIT),reipl64.o,reipl.o) diff --git a/arch/s390/kernel/jump_label.c b/arch/s390/kernel/jump_label.c new file mode 100644 index 000000000000..44cc06bedf77 --- /dev/null +++ b/arch/s390/kernel/jump_label.c @@ -0,0 +1,59 @@ +/* + * Jump label s390 support + * + * Copyright IBM Corp. 2011 + * Author(s): Jan Glauber + */ +#include +#include +#include +#include +#include + +#ifdef HAVE_JUMP_LABEL + +struct insn { + u16 opcode; + s32 offset; +} __packed; + +struct insn_args { + unsigned long *target; + struct insn *insn; + ssize_t size; +}; + +static int __arch_jump_label_transform(void *data) +{ + struct insn_args *args = data; + int rc; + + rc = probe_kernel_write(args->target, args->insn, args->size); + WARN_ON_ONCE(rc < 0); + return 0; +} + +void arch_jump_label_transform(struct jump_entry *entry, + enum jump_label_type type) +{ + struct insn_args args; + struct insn insn; + + if (type == JUMP_LABEL_ENABLE) { + /* brcl 15,offset */ + insn.opcode = 0xc0f4; + insn.offset = (entry->target - entry->code) >> 1; + } else { + /* brcl 0,0 */ + insn.opcode = 0xc004; + insn.offset = 0; + } + + args.target = (void *) entry->code; + args.insn = &insn; + args.size = JUMP_LABEL_NOP_SIZE; + + stop_machine(__arch_jump_label_transform, &args, NULL); +} + +#endif diff --git a/arch/sparc/include/asm/jump_label.h b/arch/sparc/include/asm/jump_label.h index 427d4684e0d2..fc73a82366f8 100644 --- a/arch/sparc/include/asm/jump_label.h +++ b/arch/sparc/include/asm/jump_label.h @@ -7,17 +7,20 @@ #define JUMP_LABEL_NOP_SIZE 4 -#define JUMP_LABEL(key, label) \ - do { \ - asm goto("1:\n\t" \ - "nop\n\t" \ - "nop\n\t" \ - ".pushsection __jump_table, \"a\"\n\t"\ - ".align 4\n\t" \ - ".word 1b, %l[" #label "], %c0\n\t" \ - ".popsection \n\t" \ - : : "i" (key) : : label);\ - } while (0) +static __always_inline bool arch_static_branch(struct jump_label_key *key) +{ + asm goto("1:\n\t" + "nop\n\t" + "nop\n\t" + ".pushsection __jump_table, \"aw\"\n\t" + ".align 4\n\t" + ".word 1b, %l[l_yes], %c0\n\t" + ".popsection \n\t" + : : "i" (key) : : l_yes); + return false; +l_yes: + return true; +} #endif /* __KERNEL__ */ diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h index 13009d1af99a..8cdd1e247975 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -4,7 +4,6 @@ #include #include #include -#include #include /* @@ -191,7 +190,7 @@ extern void *text_poke(void *addr, const void *opcode, size_t len); extern void *text_poke_smp(void *addr, const void *opcode, size_t len); extern void text_poke_smp_batch(struct text_poke_param *params, int n); -#if defined(CONFIG_DYNAMIC_FTRACE) || defined(HAVE_JUMP_LABEL) +#if defined(CONFIG_DYNAMIC_FTRACE) || defined(CONFIG_JUMP_LABEL) #define IDEAL_NOP_SIZE_5 5 extern unsigned char ideal_nop5[IDEAL_NOP_SIZE_5]; extern void arch_init_ideal_nop5(void); diff --git a/arch/x86/include/asm/jump_label.h b/arch/x86/include/asm/jump_label.h index 574dbc22893a..a32b18ce6ead 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -5,20 +5,25 @@ #include #include +#include #define JUMP_LABEL_NOP_SIZE 5 -# define JUMP_LABEL_INITIAL_NOP ".byte 0xe9 \n\t .long 0\n\t" +#define JUMP_LABEL_INITIAL_NOP ".byte 0xe9 \n\t .long 0\n\t" -# define JUMP_LABEL(key, label) \ - do { \ - asm goto("1:" \ - JUMP_LABEL_INITIAL_NOP \ - ".pushsection __jump_table, \"aw\" \n\t"\ - _ASM_PTR "1b, %l[" #label "], %c0 \n\t" \ - ".popsection \n\t" \ - : : "i" (key) : : label); \ - } while (0) +static __always_inline bool arch_static_branch(struct jump_label_key *key) +{ + asm goto("1:" + JUMP_LABEL_INITIAL_NOP + ".pushsection __jump_table, \"aw\" \n\t" + _ASM_ALIGN "\n\t" + _ASM_PTR "1b, %l[l_yes], %c0 \n\t" + ".popsection \n\t" + : : "i" (key) : : l_yes); + return false; +l_yes: + return true; +} #endif /* __KERNEL__ */ diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 4a234677e213..651454b0c811 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -679,7 +679,7 @@ void __kprobes text_poke_smp_batch(struct text_poke_param *params, int n) __stop_machine(stop_machine_text_poke, (void *)&tpp, NULL); } -#if defined(CONFIG_DYNAMIC_FTRACE) || defined(HAVE_JUMP_LABEL) +#if defined(CONFIG_DYNAMIC_FTRACE) || defined(CONFIG_JUMP_LABEL) #ifdef CONFIG_X86_64 unsigned char ideal_nop5[5] = { 0x66, 0x66, 0x66, 0x66, 0x90 }; diff --git a/arch/x86/kernel/module.c b/arch/x86/kernel/module.c index ab23f1ad4bf1..52f256f2cc81 100644 --- a/arch/x86/kernel/module.c +++ b/arch/x86/kernel/module.c @@ -24,6 +24,7 @@ #include #include #include +#include #include #include diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index bd297a20ab98..75a8692d144f 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -170,6 +170,10 @@ STRUCT_ALIGN(); \ *(__tracepoints) \ /* implement dynamic printk debug */ \ + . = ALIGN(8); \ + VMLINUX_SYMBOL(__start___jump_table) = .; \ + *(__jump_table) \ + VMLINUX_SYMBOL(__stop___jump_table) = .; \ . = ALIGN(8); \ VMLINUX_SYMBOL(__start___verbose) = .; \ *(__verbose) \ @@ -228,8 +232,6 @@ \ BUG_TABLE \ \ - JUMP_TABLE \ - \ /* PCI quirks */ \ .pci_fixup : AT(ADDR(.pci_fixup) - LOAD_OFFSET) { \ VMLINUX_SYMBOL(__start_pci_fixups_early) = .; \ @@ -589,14 +591,6 @@ #define BUG_TABLE #endif -#define JUMP_TABLE \ - . = ALIGN(8); \ - __jump_table : AT(ADDR(__jump_table) - LOAD_OFFSET) { \ - VMLINUX_SYMBOL(__start___jump_table) = .; \ - *(__jump_table) \ - VMLINUX_SYMBOL(__stop___jump_table) = .; \ - } - #ifdef CONFIG_PM_TRACE #define TRACEDATA \ . = ALIGN(4); \ diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index 0c9653f11c18..e747ecd48e1c 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -1,8 +1,6 @@ #ifndef _DYNAMIC_DEBUG_H #define _DYNAMIC_DEBUG_H -#include - /* dynamic_printk_enabled, and dynamic_printk_enabled2 are bitmasks in which * bit n is set to 1 if any modname hashes into the bucket n, 0 otherwise. They * use independent hash functions, to reduce the chance of false positives. diff --git a/include/linux/jump_label.h b/include/linux/jump_label.h index 7880f18e4b86..83e745f3ead7 100644 --- a/include/linux/jump_label.h +++ b/include/linux/jump_label.h @@ -1,20 +1,43 @@ #ifndef _LINUX_JUMP_LABEL_H #define _LINUX_JUMP_LABEL_H +#include +#include + #if defined(CC_HAVE_ASM_GOTO) && defined(CONFIG_JUMP_LABEL) + +struct jump_label_key { + atomic_t enabled; + struct jump_entry *entries; +#ifdef CONFIG_MODULES + struct jump_label_mod *next; +#endif +}; + # include # define HAVE_JUMP_LABEL #endif enum jump_label_type { + JUMP_LABEL_DISABLE = 0, JUMP_LABEL_ENABLE, - JUMP_LABEL_DISABLE }; struct module; #ifdef HAVE_JUMP_LABEL +#ifdef CONFIG_MODULES +#define JUMP_LABEL_INIT {{ 0 }, NULL, NULL} +#else +#define JUMP_LABEL_INIT {{ 0 }, NULL} +#endif + +static __always_inline bool static_branch(struct jump_label_key *key) +{ + return arch_static_branch(key); +} + extern struct jump_entry __start___jump_table[]; extern struct jump_entry __stop___jump_table[]; @@ -23,37 +46,37 @@ extern void jump_label_unlock(void); extern void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type); extern void arch_jump_label_text_poke_early(jump_label_t addr); -extern void jump_label_update(unsigned long key, enum jump_label_type type); -extern void jump_label_apply_nops(struct module *mod); extern int jump_label_text_reserved(void *start, void *end); - -#define jump_label_enable(key) \ - jump_label_update((unsigned long)key, JUMP_LABEL_ENABLE); - -#define jump_label_disable(key) \ - jump_label_update((unsigned long)key, JUMP_LABEL_DISABLE); +extern void jump_label_inc(struct jump_label_key *key); +extern void jump_label_dec(struct jump_label_key *key); +extern bool jump_label_enabled(struct jump_label_key *key); +extern void jump_label_apply_nops(struct module *mod); #else -#define JUMP_LABEL(key, label) \ -do { \ - if (unlikely(*key)) \ - goto label; \ -} while (0) +#include -#define jump_label_enable(cond_var) \ -do { \ - *(cond_var) = 1; \ -} while (0) +#define JUMP_LABEL_INIT {ATOMIC_INIT(0)} -#define jump_label_disable(cond_var) \ -do { \ - *(cond_var) = 0; \ -} while (0) +struct jump_label_key { + atomic_t enabled; +}; -static inline int jump_label_apply_nops(struct module *mod) +static __always_inline bool static_branch(struct jump_label_key *key) { - return 0; + if (unlikely(atomic_read(&key->enabled))) + return true; + return false; +} + +static inline void jump_label_inc(struct jump_label_key *key) +{ + atomic_inc(&key->enabled); +} + +static inline void jump_label_dec(struct jump_label_key *key) +{ + atomic_dec(&key->enabled); } static inline int jump_label_text_reserved(void *start, void *end) @@ -64,16 +87,16 @@ static inline int jump_label_text_reserved(void *start, void *end) static inline void jump_label_lock(void) {} static inline void jump_label_unlock(void) {} -#endif +static inline bool jump_label_enabled(struct jump_label_key *key) +{ + return !!atomic_read(&key->enabled); +} -#define COND_STMT(key, stmt) \ -do { \ - __label__ jl_enabled; \ - JUMP_LABEL(key, jl_enabled); \ - if (0) { \ -jl_enabled: \ - stmt; \ - } \ -} while (0) +static inline int jump_label_apply_nops(struct module *mod) +{ + return 0; +} + +#endif #endif diff --git a/include/linux/jump_label_ref.h b/include/linux/jump_label_ref.h deleted file mode 100644 index e5d012ad92c6..000000000000 --- a/include/linux/jump_label_ref.h +++ /dev/null @@ -1,44 +0,0 @@ -#ifndef _LINUX_JUMP_LABEL_REF_H -#define _LINUX_JUMP_LABEL_REF_H - -#include -#include - -#ifdef HAVE_JUMP_LABEL - -static inline void jump_label_inc(atomic_t *key) -{ - if (atomic_add_return(1, key) == 1) - jump_label_enable(key); -} - -static inline void jump_label_dec(atomic_t *key) -{ - if (atomic_dec_and_test(key)) - jump_label_disable(key); -} - -#else /* !HAVE_JUMP_LABEL */ - -static inline void jump_label_inc(atomic_t *key) -{ - atomic_inc(key); -} - -static inline void jump_label_dec(atomic_t *key) -{ - atomic_dec(key); -} - -#undef JUMP_LABEL -#define JUMP_LABEL(key, label) \ -do { \ - if (unlikely(__builtin_choose_expr( \ - __builtin_types_compatible_p(typeof(key), atomic_t *), \ - atomic_read((atomic_t *)(key)), *(key)))) \ - goto label; \ -} while (0) - -#endif /* HAVE_JUMP_LABEL */ - -#endif /* _LINUX_JUMP_LABEL_REF_H */ diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index ee9f1e782800..9eec53d97370 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -505,7 +505,7 @@ struct perf_guest_info_callbacks { #include #include #include -#include +#include #include #include @@ -1034,7 +1034,7 @@ static inline int is_software_event(struct perf_event *event) return event->pmu->task_ctx_nr == perf_sw_context; } -extern atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX]; +extern struct jump_label_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; extern void __perf_sw_event(u32, u64, int, struct pt_regs *, u64); @@ -1063,22 +1063,21 @@ perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr) { struct pt_regs hot_regs; - JUMP_LABEL(&perf_swevent_enabled[event_id], have_event); - return; - -have_event: - if (!regs) { - perf_fetch_caller_regs(&hot_regs); - regs = &hot_regs; + if (static_branch(&perf_swevent_enabled[event_id])) { + if (!regs) { + perf_fetch_caller_regs(&hot_regs); + regs = &hot_regs; + } + __perf_sw_event(event_id, nr, nmi, regs, addr); } - __perf_sw_event(event_id, nr, nmi, regs, addr); } -extern atomic_t perf_sched_events; +extern struct jump_label_key perf_sched_events; static inline void perf_event_task_sched_in(struct task_struct *task) { - COND_STMT(&perf_sched_events, __perf_event_task_sched_in(task)); + if (static_branch(&perf_sched_events)) + __perf_event_task_sched_in(task); } static inline diff --git a/include/linux/tracepoint.h b/include/linux/tracepoint.h index 97c84a58efb8..d530a4460a0b 100644 --- a/include/linux/tracepoint.h +++ b/include/linux/tracepoint.h @@ -29,7 +29,7 @@ struct tracepoint_func { struct tracepoint { const char *name; /* Tracepoint name */ - int state; /* State. */ + struct jump_label_key key; void (*regfunc)(void); void (*unregfunc)(void); struct tracepoint_func __rcu *funcs; @@ -146,9 +146,7 @@ void tracepoint_update_probe_range(struct tracepoint * const *begin, extern struct tracepoint __tracepoint_##name; \ static inline void trace_##name(proto) \ { \ - JUMP_LABEL(&__tracepoint_##name.state, do_trace); \ - return; \ -do_trace: \ + if (static_branch(&__tracepoint_##name.key)) \ __DO_TRACE(&__tracepoint_##name, \ TP_PROTO(data_proto), \ TP_ARGS(data_args), \ @@ -176,14 +174,14 @@ do_trace: \ * structures, so we create an array of pointers that will be used for iteration * on the tracepoints. */ -#define DEFINE_TRACE_FN(name, reg, unreg) \ - static const char __tpstrtab_##name[] \ - __attribute__((section("__tracepoints_strings"))) = #name; \ - struct tracepoint __tracepoint_##name \ - __attribute__((section("__tracepoints"))) = \ - { __tpstrtab_##name, 0, reg, unreg, NULL }; \ - static struct tracepoint * const __tracepoint_ptr_##name __used \ - __attribute__((section("__tracepoints_ptrs"))) = \ +#define DEFINE_TRACE_FN(name, reg, unreg) \ + static const char __tpstrtab_##name[] \ + __attribute__((section("__tracepoints_strings"))) = #name; \ + struct tracepoint __tracepoint_##name \ + __attribute__((section("__tracepoints"))) = \ + { __tpstrtab_##name, JUMP_LABEL_INIT, reg, unreg, NULL };\ + static struct tracepoint * const __tracepoint_ptr_##name __used \ + __attribute__((section("__tracepoints_ptrs"))) = \ &__tracepoint_##name; #define DEFINE_TRACE(name) \ diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 3b79bd938330..74d1c099fbd1 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -2,43 +2,23 @@ * jump label support * * Copyright (C) 2009 Jason Baron + * Copyright (C) 2011 Peter Zijlstra * */ -#include #include #include #include #include -#include #include #include #include +#include #ifdef HAVE_JUMP_LABEL -#define JUMP_LABEL_HASH_BITS 6 -#define JUMP_LABEL_TABLE_SIZE (1 << JUMP_LABEL_HASH_BITS) -static struct hlist_head jump_label_table[JUMP_LABEL_TABLE_SIZE]; - /* mutex to protect coming/going of the the jump_label table */ static DEFINE_MUTEX(jump_label_mutex); -struct jump_label_entry { - struct hlist_node hlist; - struct jump_entry *table; - int nr_entries; - /* hang modules off here */ - struct hlist_head modules; - unsigned long key; -}; - -struct jump_label_module_entry { - struct hlist_node hlist; - struct jump_entry *table; - int nr_entries; - struct module *mod; -}; - void jump_label_lock(void) { mutex_lock(&jump_label_mutex); @@ -49,6 +29,11 @@ void jump_label_unlock(void) mutex_unlock(&jump_label_mutex); } +bool jump_label_enabled(struct jump_label_key *key) +{ + return !!atomic_read(&key->enabled); +} + static int jump_label_cmp(const void *a, const void *b) { const struct jump_entry *jea = a; @@ -64,7 +49,7 @@ static int jump_label_cmp(const void *a, const void *b) } static void -sort_jump_label_entries(struct jump_entry *start, struct jump_entry *stop) +jump_label_sort_entries(struct jump_entry *start, struct jump_entry *stop) { unsigned long size; @@ -73,118 +58,25 @@ sort_jump_label_entries(struct jump_entry *start, struct jump_entry *stop) sort(start, size, sizeof(struct jump_entry), jump_label_cmp, NULL); } -static struct jump_label_entry *get_jump_label_entry(jump_label_t key) +static void jump_label_update(struct jump_label_key *key, int enable); + +void jump_label_inc(struct jump_label_key *key) { - struct hlist_head *head; - struct hlist_node *node; - struct jump_label_entry *e; - u32 hash = jhash((void *)&key, sizeof(jump_label_t), 0); - - head = &jump_label_table[hash & (JUMP_LABEL_TABLE_SIZE - 1)]; - hlist_for_each_entry(e, node, head, hlist) { - if (key == e->key) - return e; - } - return NULL; -} - -static struct jump_label_entry * -add_jump_label_entry(jump_label_t key, int nr_entries, struct jump_entry *table) -{ - struct hlist_head *head; - struct jump_label_entry *e; - u32 hash; - - e = get_jump_label_entry(key); - if (e) - return ERR_PTR(-EEXIST); - - e = kmalloc(sizeof(struct jump_label_entry), GFP_KERNEL); - if (!e) - return ERR_PTR(-ENOMEM); - - hash = jhash((void *)&key, sizeof(jump_label_t), 0); - head = &jump_label_table[hash & (JUMP_LABEL_TABLE_SIZE - 1)]; - e->key = key; - e->table = table; - e->nr_entries = nr_entries; - INIT_HLIST_HEAD(&(e->modules)); - hlist_add_head(&e->hlist, head); - return e; -} - -static int -build_jump_label_hashtable(struct jump_entry *start, struct jump_entry *stop) -{ - struct jump_entry *iter, *iter_begin; - struct jump_label_entry *entry; - int count; - - sort_jump_label_entries(start, stop); - iter = start; - while (iter < stop) { - entry = get_jump_label_entry(iter->key); - if (!entry) { - iter_begin = iter; - count = 0; - while ((iter < stop) && - (iter->key == iter_begin->key)) { - iter++; - count++; - } - entry = add_jump_label_entry(iter_begin->key, - count, iter_begin); - if (IS_ERR(entry)) - return PTR_ERR(entry); - } else { - WARN_ONCE(1, KERN_ERR "build_jump_hashtable: unexpected entry!\n"); - return -1; - } - } - return 0; -} - -/*** - * jump_label_update - update jump label text - * @key - key value associated with a a jump label - * @type - enum set to JUMP_LABEL_ENABLE or JUMP_LABEL_DISABLE - * - * Will enable/disable the jump for jump label @key, depending on the - * value of @type. - * - */ - -void jump_label_update(unsigned long key, enum jump_label_type type) -{ - struct jump_entry *iter; - struct jump_label_entry *entry; - struct hlist_node *module_node; - struct jump_label_module_entry *e_module; - int count; + if (atomic_inc_not_zero(&key->enabled)) + return; jump_label_lock(); - entry = get_jump_label_entry((jump_label_t)key); - if (entry) { - count = entry->nr_entries; - iter = entry->table; - while (count--) { - if (kernel_text_address(iter->code)) - arch_jump_label_transform(iter, type); - iter++; - } - /* eanble/disable jump labels in modules */ - hlist_for_each_entry(e_module, module_node, &(entry->modules), - hlist) { - count = e_module->nr_entries; - iter = e_module->table; - while (count--) { - if (iter->key && - kernel_text_address(iter->code)) - arch_jump_label_transform(iter, type); - iter++; - } - } - } + if (atomic_add_return(1, &key->enabled) == 1) + jump_label_update(key, JUMP_LABEL_ENABLE); + jump_label_unlock(); +} + +void jump_label_dec(struct jump_label_key *key) +{ + if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) + return; + + jump_label_update(key, JUMP_LABEL_DISABLE); jump_label_unlock(); } @@ -197,41 +89,254 @@ static int addr_conflict(struct jump_entry *entry, void *start, void *end) return 0; } -#ifdef CONFIG_MODULES - -static int module_conflict(void *start, void *end) +static int __jump_label_text_reserved(struct jump_entry *iter_start, + struct jump_entry *iter_stop, void *start, void *end) { - struct hlist_head *head; - struct hlist_node *node, *node_next, *module_node, *module_node_next; - struct jump_label_entry *e; - struct jump_label_module_entry *e_module; struct jump_entry *iter; - int i, count; - int conflict = 0; - for (i = 0; i < JUMP_LABEL_TABLE_SIZE; i++) { - head = &jump_label_table[i]; - hlist_for_each_entry_safe(e, node, node_next, head, hlist) { - hlist_for_each_entry_safe(e_module, module_node, - module_node_next, - &(e->modules), hlist) { - count = e_module->nr_entries; - iter = e_module->table; - while (count--) { - if (addr_conflict(iter, start, end)) { - conflict = 1; - goto out; - } - iter++; - } - } - } + iter = iter_start; + while (iter < iter_stop) { + if (addr_conflict(iter, start, end)) + return 1; + iter++; } -out: - return conflict; + + return 0; } +static void __jump_label_update(struct jump_label_key *key, + struct jump_entry *entry, int enable) +{ + for (; entry->key == (jump_label_t)(unsigned long)key; entry++) { + /* + * entry->code set to 0 invalidates module init text sections + * kernel_text_address() verifies we are not in core kernel + * init code, see jump_label_invalidate_module_init(). + */ + if (entry->code && kernel_text_address(entry->code)) + arch_jump_label_transform(entry, enable); + } +} + +/* + * Not all archs need this. + */ +void __weak arch_jump_label_text_poke_early(jump_label_t addr) +{ +} + +static __init int jump_label_init(void) +{ + struct jump_entry *iter_start = __start___jump_table; + struct jump_entry *iter_stop = __stop___jump_table; + struct jump_label_key *key = NULL; + struct jump_entry *iter; + + jump_label_lock(); + jump_label_sort_entries(iter_start, iter_stop); + + for (iter = iter_start; iter < iter_stop; iter++) { + arch_jump_label_text_poke_early(iter->code); + if (iter->key == (jump_label_t)(unsigned long)key) + continue; + + key = (struct jump_label_key *)(unsigned long)iter->key; + atomic_set(&key->enabled, 0); + key->entries = iter; +#ifdef CONFIG_MODULES + key->next = NULL; #endif + } + jump_label_unlock(); + + return 0; +} +early_initcall(jump_label_init); + +#ifdef CONFIG_MODULES + +struct jump_label_mod { + struct jump_label_mod *next; + struct jump_entry *entries; + struct module *mod; +}; + +static int __jump_label_mod_text_reserved(void *start, void *end) +{ + struct module *mod; + + mod = __module_text_address((unsigned long)start); + if (!mod) + return 0; + + WARN_ON_ONCE(__module_text_address((unsigned long)end) != mod); + + return __jump_label_text_reserved(mod->jump_entries, + mod->jump_entries + mod->num_jump_entries, + start, end); +} + +static void __jump_label_mod_update(struct jump_label_key *key, int enable) +{ + struct jump_label_mod *mod = key->next; + + while (mod) { + __jump_label_update(key, mod->entries, enable); + mod = mod->next; + } +} + +/*** + * apply_jump_label_nops - patch module jump labels with arch_get_jump_label_nop() + * @mod: module to patch + * + * Allow for run-time selection of the optimal nops. Before the module + * loads patch these with arch_get_jump_label_nop(), which is specified by + * the arch specific jump label code. + */ +void jump_label_apply_nops(struct module *mod) +{ + struct jump_entry *iter_start = mod->jump_entries; + struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; + struct jump_entry *iter; + + /* if the module doesn't have jump label entries, just return */ + if (iter_start == iter_stop) + return; + + for (iter = iter_start; iter < iter_stop; iter++) + arch_jump_label_text_poke_early(iter->code); +} + +static int jump_label_add_module(struct module *mod) +{ + struct jump_entry *iter_start = mod->jump_entries; + struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; + struct jump_entry *iter; + struct jump_label_key *key = NULL; + struct jump_label_mod *jlm; + + /* if the module doesn't have jump label entries, just return */ + if (iter_start == iter_stop) + return 0; + + jump_label_sort_entries(iter_start, iter_stop); + + for (iter = iter_start; iter < iter_stop; iter++) { + if (iter->key == (jump_label_t)(unsigned long)key) + continue; + + key = (struct jump_label_key *)(unsigned long)iter->key; + + if (__module_address(iter->key) == mod) { + atomic_set(&key->enabled, 0); + key->entries = iter; + key->next = NULL; + continue; + } + + jlm = kzalloc(sizeof(struct jump_label_mod), GFP_KERNEL); + if (!jlm) + return -ENOMEM; + + jlm->mod = mod; + jlm->entries = iter; + jlm->next = key->next; + key->next = jlm; + + if (jump_label_enabled(key)) + __jump_label_update(key, iter, JUMP_LABEL_ENABLE); + } + + return 0; +} + +static void jump_label_del_module(struct module *mod) +{ + struct jump_entry *iter_start = mod->jump_entries; + struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; + struct jump_entry *iter; + struct jump_label_key *key = NULL; + struct jump_label_mod *jlm, **prev; + + for (iter = iter_start; iter < iter_stop; iter++) { + if (iter->key == (jump_label_t)(unsigned long)key) + continue; + + key = (struct jump_label_key *)(unsigned long)iter->key; + + if (__module_address(iter->key) == mod) + continue; + + prev = &key->next; + jlm = key->next; + + while (jlm && jlm->mod != mod) { + prev = &jlm->next; + jlm = jlm->next; + } + + if (jlm) { + *prev = jlm->next; + kfree(jlm); + } + } +} + +static void jump_label_invalidate_module_init(struct module *mod) +{ + struct jump_entry *iter_start = mod->jump_entries; + struct jump_entry *iter_stop = iter_start + mod->num_jump_entries; + struct jump_entry *iter; + + for (iter = iter_start; iter < iter_stop; iter++) { + if (within_module_init(iter->code, mod)) + iter->code = 0; + } +} + +static int +jump_label_module_notify(struct notifier_block *self, unsigned long val, + void *data) +{ + struct module *mod = data; + int ret = 0; + + switch (val) { + case MODULE_STATE_COMING: + jump_label_lock(); + ret = jump_label_add_module(mod); + if (ret) + jump_label_del_module(mod); + jump_label_unlock(); + break; + case MODULE_STATE_GOING: + jump_label_lock(); + jump_label_del_module(mod); + jump_label_unlock(); + break; + case MODULE_STATE_LIVE: + jump_label_lock(); + jump_label_invalidate_module_init(mod); + jump_label_unlock(); + break; + } + + return notifier_from_errno(ret); +} + +struct notifier_block jump_label_module_nb = { + .notifier_call = jump_label_module_notify, + .priority = 1, /* higher than tracepoints */ +}; + +static __init int jump_label_init_module(void) +{ + return register_module_notifier(&jump_label_module_nb); +} +early_initcall(jump_label_init_module); + +#endif /* CONFIG_MODULES */ /*** * jump_label_text_reserved - check if addr range is reserved @@ -248,237 +353,29 @@ static int module_conflict(void *start, void *end) */ int jump_label_text_reserved(void *start, void *end) { - struct jump_entry *iter; - struct jump_entry *iter_start = __start___jump_table; - struct jump_entry *iter_stop = __start___jump_table; - int conflict = 0; + int ret = __jump_label_text_reserved(__start___jump_table, + __stop___jump_table, start, end); - iter = iter_start; - while (iter < iter_stop) { - if (addr_conflict(iter, start, end)) { - conflict = 1; - goto out; - } - iter++; - } + if (ret) + return ret; - /* now check modules */ #ifdef CONFIG_MODULES - conflict = module_conflict(start, end); + ret = __jump_label_mod_text_reserved(start, end); #endif -out: - return conflict; -} - -/* - * Not all archs need this. - */ -void __weak arch_jump_label_text_poke_early(jump_label_t addr) -{ -} - -static __init int init_jump_label(void) -{ - int ret; - struct jump_entry *iter_start = __start___jump_table; - struct jump_entry *iter_stop = __stop___jump_table; - struct jump_entry *iter; - - jump_label_lock(); - ret = build_jump_label_hashtable(__start___jump_table, - __stop___jump_table); - iter = iter_start; - while (iter < iter_stop) { - arch_jump_label_text_poke_early(iter->code); - iter++; - } - jump_label_unlock(); - return ret; -} -early_initcall(init_jump_label); - -#ifdef CONFIG_MODULES - -static struct jump_label_module_entry * -add_jump_label_module_entry(struct jump_label_entry *entry, - struct jump_entry *iter_begin, - int count, struct module *mod) -{ - struct jump_label_module_entry *e; - - e = kmalloc(sizeof(struct jump_label_module_entry), GFP_KERNEL); - if (!e) - return ERR_PTR(-ENOMEM); - e->mod = mod; - e->nr_entries = count; - e->table = iter_begin; - hlist_add_head(&e->hlist, &entry->modules); - return e; -} - -static int add_jump_label_module(struct module *mod) -{ - struct jump_entry *iter, *iter_begin; - struct jump_label_entry *entry; - struct jump_label_module_entry *module_entry; - int count; - - /* if the module doesn't have jump label entries, just return */ - if (!mod->num_jump_entries) - return 0; - - sort_jump_label_entries(mod->jump_entries, - mod->jump_entries + mod->num_jump_entries); - iter = mod->jump_entries; - while (iter < mod->jump_entries + mod->num_jump_entries) { - entry = get_jump_label_entry(iter->key); - iter_begin = iter; - count = 0; - while ((iter < mod->jump_entries + mod->num_jump_entries) && - (iter->key == iter_begin->key)) { - iter++; - count++; - } - if (!entry) { - entry = add_jump_label_entry(iter_begin->key, 0, NULL); - if (IS_ERR(entry)) - return PTR_ERR(entry); - } - module_entry = add_jump_label_module_entry(entry, iter_begin, - count, mod); - if (IS_ERR(module_entry)) - return PTR_ERR(module_entry); - } - return 0; -} - -static void remove_jump_label_module(struct module *mod) -{ - struct hlist_head *head; - struct hlist_node *node, *node_next, *module_node, *module_node_next; - struct jump_label_entry *e; - struct jump_label_module_entry *e_module; - int i; - - /* if the module doesn't have jump label entries, just return */ - if (!mod->num_jump_entries) - return; - - for (i = 0; i < JUMP_LABEL_TABLE_SIZE; i++) { - head = &jump_label_table[i]; - hlist_for_each_entry_safe(e, node, node_next, head, hlist) { - hlist_for_each_entry_safe(e_module, module_node, - module_node_next, - &(e->modules), hlist) { - if (e_module->mod == mod) { - hlist_del(&e_module->hlist); - kfree(e_module); - } - } - if (hlist_empty(&e->modules) && (e->nr_entries == 0)) { - hlist_del(&e->hlist); - kfree(e); - } - } - } -} - -static void remove_jump_label_module_init(struct module *mod) -{ - struct hlist_head *head; - struct hlist_node *node, *node_next, *module_node, *module_node_next; - struct jump_label_entry *e; - struct jump_label_module_entry *e_module; - struct jump_entry *iter; - int i, count; - - /* if the module doesn't have jump label entries, just return */ - if (!mod->num_jump_entries) - return; - - for (i = 0; i < JUMP_LABEL_TABLE_SIZE; i++) { - head = &jump_label_table[i]; - hlist_for_each_entry_safe(e, node, node_next, head, hlist) { - hlist_for_each_entry_safe(e_module, module_node, - module_node_next, - &(e->modules), hlist) { - if (e_module->mod != mod) - continue; - count = e_module->nr_entries; - iter = e_module->table; - while (count--) { - if (within_module_init(iter->code, mod)) - iter->key = 0; - iter++; - } - } - } - } -} - -static int -jump_label_module_notify(struct notifier_block *self, unsigned long val, - void *data) -{ - struct module *mod = data; - int ret = 0; - - switch (val) { - case MODULE_STATE_COMING: - jump_label_lock(); - ret = add_jump_label_module(mod); - if (ret) - remove_jump_label_module(mod); - jump_label_unlock(); - break; - case MODULE_STATE_GOING: - jump_label_lock(); - remove_jump_label_module(mod); - jump_label_unlock(); - break; - case MODULE_STATE_LIVE: - jump_label_lock(); - remove_jump_label_module_init(mod); - jump_label_unlock(); - break; - } return ret; } -/*** - * apply_jump_label_nops - patch module jump labels with arch_get_jump_label_nop() - * @mod: module to patch - * - * Allow for run-time selection of the optimal nops. Before the module - * loads patch these with arch_get_jump_label_nop(), which is specified by - * the arch specific jump label code. - */ -void jump_label_apply_nops(struct module *mod) +static void jump_label_update(struct jump_label_key *key, int enable) { - struct jump_entry *iter; + struct jump_entry *entry = key->entries; - /* if the module doesn't have jump label entries, just return */ - if (!mod->num_jump_entries) - return; + /* if there are no users, entry can be NULL */ + if (entry) + __jump_label_update(key, entry, enable); - iter = mod->jump_entries; - while (iter < mod->jump_entries + mod->num_jump_entries) { - arch_jump_label_text_poke_early(iter->code); - iter++; - } +#ifdef CONFIG_MODULES + __jump_label_mod_update(key, enable); +#endif } -struct notifier_block jump_label_module_nb = { - .notifier_call = jump_label_module_notify, - .priority = 0, -}; - -static __init int init_jump_label_module(void) -{ - return register_module_notifier(&jump_label_module_nb); -} -early_initcall(init_jump_label_module); - -#endif /* CONFIG_MODULES */ - #endif diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 8e81a9860a0d..440bc485bbff 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -125,7 +125,7 @@ enum event_type_t { * perf_sched_events : >0 events exist * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu */ -atomic_t perf_sched_events __read_mostly; +struct jump_label_key perf_sched_events __read_mostly; static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); static atomic_t nr_mmap_events __read_mostly; @@ -5429,7 +5429,7 @@ static int swevent_hlist_get(struct perf_event *event) return err; } -atomic_t perf_swevent_enabled[PERF_COUNT_SW_MAX]; +struct jump_label_key perf_swevent_enabled[PERF_COUNT_SW_MAX]; static void sw_perf_event_destroy(struct perf_event *event) { diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d38c16a06a6f..e0e14ce0caab 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2013,9 +2013,10 @@ enum print_line_t print_trace_line(struct trace_iterator *iter) { enum print_line_t ret; - if (iter->lost_events) - trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", - iter->cpu, iter->lost_events); + if (iter->lost_events && + !trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n", + iter->cpu, iter->lost_events)) + return TRACE_TYPE_PARTIAL_LINE; if (iter->trace && iter->trace->print_line) { ret = iter->trace->print_line(iter); @@ -3229,6 +3230,14 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, if (iter->seq.len >= cnt) break; + + /* + * Setting the full flag means we reached the trace_seq buffer + * size and we should leave by partial output condition above. + * One of the trace_seq_* functions is not used properly. + */ + WARN_ONCE(iter->seq.full, "full flag set for trace type %d", + iter->ent->type); } trace_access_unlock(iter->cpu_file); trace_event_read_unlock(); diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 456be9063c2d..cf535ccedc86 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -830,6 +830,9 @@ EXPORT_SYMBOL_GPL(unregister_ftrace_event); enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags, struct trace_event *event) { + if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type)) + return TRACE_TYPE_PARTIAL_LINE; + return TRACE_TYPE_HANDLED; } diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index 2547d8813cf0..dff763b7baf1 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -32,7 +32,7 @@ static DEFINE_MUTEX(btrace_mutex); struct trace_bprintk_fmt { struct list_head list; - char fmt[0]; + const char *fmt; }; static inline struct trace_bprintk_fmt *lookup_format(const char *fmt) @@ -49,6 +49,7 @@ static void hold_module_trace_bprintk_format(const char **start, const char **end) { const char **iter; + char *fmt; mutex_lock(&btrace_mutex); for (iter = start; iter < end; iter++) { @@ -58,14 +59,18 @@ void hold_module_trace_bprintk_format(const char **start, const char **end) continue; } - tb_fmt = kmalloc(offsetof(struct trace_bprintk_fmt, fmt) - + strlen(*iter) + 1, GFP_KERNEL); - if (tb_fmt) { + tb_fmt = kmalloc(sizeof(*tb_fmt), GFP_KERNEL); + if (tb_fmt) + fmt = kmalloc(strlen(*iter) + 1, GFP_KERNEL); + if (tb_fmt && fmt) { list_add_tail(&tb_fmt->list, &trace_bprintk_fmt_list); - strcpy(tb_fmt->fmt, *iter); + strcpy(fmt, *iter); + tb_fmt->fmt = fmt; *iter = tb_fmt->fmt; - } else + } else { + kfree(tb_fmt); *iter = NULL; + } } mutex_unlock(&btrace_mutex); } @@ -84,6 +89,76 @@ static int module_trace_bprintk_format_notify(struct notifier_block *self, return 0; } +/* + * The debugfs/tracing/printk_formats file maps the addresses with + * the ASCII formats that are used in the bprintk events in the + * buffer. For userspace tools to be able to decode the events from + * the buffer, they need to be able to map the address with the format. + * + * The addresses of the bprintk formats are in their own section + * __trace_printk_fmt. But for modules we copy them into a link list. + * The code to print the formats and their addresses passes around the + * address of the fmt string. If the fmt address passed into the seq + * functions is within the kernel core __trace_printk_fmt section, then + * it simply uses the next pointer in the list. + * + * When the fmt pointer is outside the kernel core __trace_printk_fmt + * section, then we need to read the link list pointers. The trick is + * we pass the address of the string to the seq function just like + * we do for the kernel core formats. To get back the structure that + * holds the format, we simply use containerof() and then go to the + * next format in the list. + */ +static const char ** +find_next_mod_format(int start_index, void *v, const char **fmt, loff_t *pos) +{ + struct trace_bprintk_fmt *mod_fmt; + + if (list_empty(&trace_bprintk_fmt_list)) + return NULL; + + /* + * v will point to the address of the fmt record from t_next + * v will be NULL from t_start. + * If this is the first pointer or called from start + * then we need to walk the list. + */ + if (!v || start_index == *pos) { + struct trace_bprintk_fmt *p; + + /* search the module list */ + list_for_each_entry(p, &trace_bprintk_fmt_list, list) { + if (start_index == *pos) + return &p->fmt; + start_index++; + } + /* pos > index */ + return NULL; + } + + /* + * v points to the address of the fmt field in the mod list + * structure that holds the module print format. + */ + mod_fmt = container_of(v, typeof(*mod_fmt), fmt); + if (mod_fmt->list.next == &trace_bprintk_fmt_list) + return NULL; + + mod_fmt = container_of(mod_fmt->list.next, typeof(*mod_fmt), list); + + return &mod_fmt->fmt; +} + +static void format_mod_start(void) +{ + mutex_lock(&btrace_mutex); +} + +static void format_mod_stop(void) +{ + mutex_unlock(&btrace_mutex); +} + #else /* !CONFIG_MODULES */ __init static int module_trace_bprintk_format_notify(struct notifier_block *self, @@ -91,6 +166,13 @@ module_trace_bprintk_format_notify(struct notifier_block *self, { return 0; } +static inline const char ** +find_next_mod_format(int start_index, void *v, const char **fmt, loff_t *pos) +{ + return NULL; +} +static inline void format_mod_start(void) { } +static inline void format_mod_stop(void) { } #endif /* CONFIG_MODULES */ @@ -153,20 +235,33 @@ int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap) } EXPORT_SYMBOL_GPL(__ftrace_vprintk); +static const char **find_next(void *v, loff_t *pos) +{ + const char **fmt = v; + int start_index; + + if (!fmt) + fmt = __start___trace_bprintk_fmt + *pos; + + start_index = __stop___trace_bprintk_fmt - __start___trace_bprintk_fmt; + + if (*pos < start_index) + return fmt; + + return find_next_mod_format(start_index, v, fmt, pos); +} + static void * t_start(struct seq_file *m, loff_t *pos) { - const char **fmt = __start___trace_bprintk_fmt + *pos; - - if ((unsigned long)fmt >= (unsigned long)__stop___trace_bprintk_fmt) - return NULL; - return fmt; + format_mod_start(); + return find_next(NULL, pos); } static void *t_next(struct seq_file *m, void * v, loff_t *pos) { (*pos)++; - return t_start(m, pos); + return find_next(v, pos); } static int t_show(struct seq_file *m, void *v) @@ -205,6 +300,7 @@ static int t_show(struct seq_file *m, void *v) static void t_stop(struct seq_file *m, void *p) { + format_mod_stop(); } static const struct seq_operations show_format_seq_ops = { diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 68187af4889e..b219f1449c54 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -251,9 +251,9 @@ static void set_tracepoint(struct tracepoint_entry **entry, { WARN_ON(strcmp((*entry)->name, elem->name) != 0); - if (elem->regfunc && !elem->state && active) + if (elem->regfunc && !jump_label_enabled(&elem->key) && active) elem->regfunc(); - else if (elem->unregfunc && elem->state && !active) + else if (elem->unregfunc && jump_label_enabled(&elem->key) && !active) elem->unregfunc(); /* @@ -264,13 +264,10 @@ static void set_tracepoint(struct tracepoint_entry **entry, * is used. */ rcu_assign_pointer(elem->funcs, (*entry)->funcs); - if (!elem->state && active) { - jump_label_enable(&elem->state); - elem->state = active; - } else if (elem->state && !active) { - jump_label_disable(&elem->state); - elem->state = active; - } + if (active && !jump_label_enabled(&elem->key)) + jump_label_inc(&elem->key); + else if (!active && jump_label_enabled(&elem->key)) + jump_label_dec(&elem->key); } /* @@ -281,13 +278,11 @@ static void set_tracepoint(struct tracepoint_entry **entry, */ static void disable_tracepoint(struct tracepoint *elem) { - if (elem->unregfunc && elem->state) + if (elem->unregfunc && jump_label_enabled(&elem->key)) elem->unregfunc(); - if (elem->state) { - jump_label_disable(&elem->state); - elem->state = 0; - } + if (jump_label_enabled(&elem->key)) + jump_label_dec(&elem->key); rcu_assign_pointer(elem->funcs, NULL); }