diff options
| -rw-r--r-- | arch/mips/include/asm/jump_label.h | 22 | ||||
| -rw-r--r-- | arch/s390/Kconfig | 1 | ||||
| -rw-r--r-- | arch/s390/include/asm/jump_label.h | 37 | ||||
| -rw-r--r-- | arch/s390/kernel/Makefile | 2 | ||||
| -rw-r--r-- | arch/s390/kernel/jump_label.c | 59 | ||||
| -rw-r--r-- | arch/sparc/include/asm/jump_label.h | 25 | ||||
| -rw-r--r-- | arch/x86/include/asm/alternative.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/jump_label.h | 27 | ||||
| -rw-r--r-- | arch/x86/kernel/alternative.c | 2 | ||||
| -rw-r--r-- | arch/x86/kernel/module.c | 1 | ||||
| -rw-r--r-- | include/asm-generic/vmlinux.lds.h | 14 | ||||
| -rw-r--r-- | include/linux/dynamic_debug.h | 2 | ||||
| -rw-r--r-- | include/linux/jump_label.h | 89 | ||||
| -rw-r--r-- | include/linux/jump_label_ref.h | 44 | ||||
| -rw-r--r-- | include/linux/perf_event.h | 23 | ||||
| -rw-r--r-- | include/linux/tracepoint.h | 22 | ||||
| -rw-r--r-- | kernel/jump_label.c | 539 | ||||
| -rw-r--r-- | kernel/perf_event.c | 4 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 15 | ||||
| -rw-r--r-- | kernel/trace/trace_output.c | 3 | ||||
| -rw-r--r-- | kernel/trace/trace_printk.c | 120 | ||||
| -rw-r--r-- | kernel/tracepoint.c | 23 |
22 files changed, 576 insertions, 501 deletions
diff --git a/arch/mips/include/asm/jump_label.h b/arch/mips/include/asm/jump_label.h index 7622ccf7507..1881b316ca4 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 2508a6f3158..4a7f14079e0 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 00000000000..95a6cf2b5b6 --- /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 <linux/types.h> + +#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 64230bc392f..5ff15dacb57 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 00000000000..44cc06bedf7 --- /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 <jang@linux.vnet.ibm.com> + */ +#include <linux/module.h> +#include <linux/uaccess.h> +#include <linux/stop_machine.h> +#include <linux/jump_label.h> +#include <asm/ipl.h> + +#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 427d4684e0d..fc73a82366f 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 13009d1af99..8cdd1e24797 100644 --- a/arch/x86/include/asm/alternative.h +++ b/arch/x86/include/asm/alternative.h @@ -4,7 +4,6 @@ #include <linux/types.h> #include <linux/stddef.h> #include <linux/stringify.h> -#include <linux/jump_label.h> #include <asm/asm.h> /* @@ -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 574dbc22893..a32b18ce6ea 100644 --- a/arch/x86/include/asm/jump_label.h +++ b/arch/x86/include/asm/jump_label.h @@ -5,20 +5,25 @@ #include <linux/types.h> #include <asm/nops.h> +#include <asm/asm.h> #define JUMP_LABEL_NOP_SIZE 5 -# 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) +#define JUMP_LABEL_INITIAL_NOP ".byte 0xe9 \n\t .long 0\n\t" + +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 4a234677e21..651454b0c81 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 ab23f1ad4bf..52f256f2cc8 100644 --- a/arch/x86/kernel/module.c +++ b/arch/x86/kernel/module.c @@ -24,6 +24,7 @@ #include <linux/bug.h> #include <linux/mm.h> #include <linux/gfp.h> +#include <linux/jump_label.h> #include <asm/system.h> #include <asm/page.h> diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index bd297a20ab9..75a8692d144 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 0c9653f11c1..e747ecd48e1 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 <linux/jump_label.h> - /* 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 7880f18e4b8..83e745f3ead 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 <linux/types.h> +#include <linux/compiler.h> + #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 <asm/jump_label.h> # 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); +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); -#define jump_label_enable(key) \ - jump_label_update((unsigned long)key, JUMP_LABEL_ENABLE); +#else -#define jump_label_disable(key) \ - jump_label_update((unsigned long)key, JUMP_LABEL_DISABLE); +#include <asm/atomic.h> -#else +#define JUMP_LABEL_INIT {ATOMIC_INIT(0)} -#define JUMP_LABEL(key, label) \ -do { \ - if (unlikely(*key)) \ - goto label; \ -} while (0) +struct jump_label_key { + atomic_t enabled; +}; -#define jump_label_enable(cond_var) \ -do { \ - *(cond_var) = 1; \ -} while (0) +static __always_inline bool static_branch(struct jump_label_key *key) +{ + if (unlikely(atomic_read(&key->enabled))) + return true; + return false; +} -#define jump_label_disable(cond_var) \ -do { \ - *(cond_var) = 0; \ -} while (0) +static inline void jump_label_inc(struct jump_label_key *key) +{ + atomic_inc(&key->enabled); +} -static inline int jump_label_apply_nops(struct module *mod) +static inline void jump_label_dec(struct jump_label_key *key) { - return 0; + 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 e5d012ad92c..00000000000 --- 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 <linux/jump_label.h> -#include <asm/atomic.h> - -#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 ee9f1e78280..9eec53d9737 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -505,7 +505,7 @@ struct perf_guest_info_callbacks { #include <linux/ftrace.h> #include <linux/cpu.h> #include <linux/irq_work.h> -#include <linux/jump_label_ref.h> +#include <linux/jump_label.h> #include <asm/atomic.h> #include <asm/local.h> @@ -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 97c84a58efb..d530a4460a0 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 3b79bd93833..74d1c099fbd 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -2,43 +2,23 @@ * jump label support * * Copyright (C) 2009 Jason Baron <jbaron@redhat.com> + * Copyright (C) 2011 Peter Zijlstra <pzijlstr@redhat.com> * */ -#include <linux/jump_label.h> #include <linux/memory.h> #include <linux/uaccess.h> #include <linux/module.h> #include <linux/list.h> -#include <linux/jhash.h> #include <linux/slab.h> #include <linux/sort.h> #include <linux/err.h> +#include <linux/jump_label.h> #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) -{ - 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 void jump_label_update(struct jump_label_key *key, int enable); -static struct jump_label_entry * -add_jump_label_entry(jump_label_t key, int nr_entries, struct jump_entry *table) +void jump_label_inc(struct jump_label_key *key) { - 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; -} + if (atomic_inc_not_zero(&key->enabled)) + return; -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_lock(); + if (atomic_add_return(1, &key->enabled) == 1) + jump_label_update(key, JUMP_LABEL_ENABLE); + jump_label_unlock(); } -/*** - * 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) +void jump_label_dec(struct jump_label_key *key) { - 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_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) + 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++; - } - } - } + jump_label_update(key, JUMP_LABEL_DISABLE); jump_label_unlock(); } @@ -197,77 +89,33 @@ 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++; - } - } - } - } -out: - return conflict; -} - -#endif - -/*** - * jump_label_text_reserved - check if addr range is reserved - * @start: start text addr - * @end: end text addr - * - * checks if the text addr located between @start and @end - * overlaps with any of the jump label patch addresses. Code - * that wants to modify kernel text should first verify that - * it does not overlap with any of the jump label addresses. - * Caller must hold jump_label_mutex. - * - * returns 1 if there is an overlap, 0 otherwise - */ -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; iter = iter_start; while (iter < iter_stop) { - if (addr_conflict(iter, start, end)) { - conflict = 1; - goto out; - } + if (addr_conflict(iter, start, end)) + return 1; iter++; } - /* now check modules */ -#ifdef CONFIG_MODULES - conflict = module_conflict(start, end); -#endif -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); + } } /* @@ -277,142 +125,173 @@ void __weak arch_jump_label_text_poke_early(jump_label_t addr) { } -static __init int init_jump_label(void) +static __init int jump_label_init(void) { - int ret; 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(); - ret = build_jump_label_hashtable(__start___jump_table, - __stop___jump_table); - iter = iter_start; - while (iter < iter_stop) { + jump_label_sort_entries(iter_start, iter_stop); + + for (iter = iter_start; iter < iter_stop; iter++) { arch_jump_label_text_poke_early(iter->code); - iter++; + 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 ret; + + return 0; } -early_initcall(init_jump_label); +early_initcall(jump_label_init); #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_mod { |