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-rw-r--r--arch/mips/include/asm/jump_label.h22
-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/include/asm/jump_label.h37
-rw-r--r--arch/s390/kernel/Makefile2
-rw-r--r--arch/s390/kernel/jump_label.c59
-rw-r--r--arch/sparc/include/asm/jump_label.h25
-rw-r--r--arch/x86/include/asm/alternative.h3
-rw-r--r--arch/x86/include/asm/jump_label.h27
-rw-r--r--arch/x86/kernel/alternative.c2
-rw-r--r--arch/x86/kernel/module.c1
-rw-r--r--include/asm-generic/vmlinux.lds.h14
-rw-r--r--include/linux/dynamic_debug.h2
-rw-r--r--include/linux/jump_label.h89
-rw-r--r--include/linux/jump_label_ref.h44
-rw-r--r--include/linux/perf_event.h23
-rw-r--r--include/linux/tracepoint.h22
-rw-r--r--kernel/jump_label.c539
-rw-r--r--kernel/perf_event.c4
-rw-r--r--kernel/trace/trace.c15
-rw-r--r--kernel/trace/trace_output.c3
-rw-r--r--kernel/trace/trace_printk.c120
-rw-r--r--kernel/tracepoint.c23
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 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 <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 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 <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 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 <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 574dbc22893a..a32b18ce6ead 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 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 <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 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 <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 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 <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 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 <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 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 <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 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 <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 {
+ 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_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;
+ 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 add_jump_label_module(struct module *mod)
+static int jump_label_add_module(struct module *mod)
{
- struct jump_entry *iter, *iter_begin;
- struct jump_label_entry *entry;
- struct jump_label_module_entry *module_entry;
- int count;
+ 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 (!mod->num_jump_entries)
+ if (iter_start == iter_stop)
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);
+ 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;
}
- module_entry = add_jump_label_module_entry(entry, iter_begin,
- count, mod);
- if (IS_ERR(module_entry))
- return PTR_ERR(module_entry);
+
+ 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 remove_jump_label_module(struct module *mod)
+static void jump_label_del_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;
+ 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;
- /* if the module doesn't have jump label entries, just return */
- if (!mod->num_jump_entries)
- return;
+ 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;
- 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);
- }
+ while (jlm && jlm->mod != mod) {
+ prev = &jlm->next;
+ jlm = jlm->next;
+ }
+
+ if (jlm) {
+ *prev = jlm->next;
+ kfree(jlm);
}
}
}
-static void remove_jump_label_module_init(struct module *mod)
+static void jump_label_invalidate_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_start = mod->jump_entries;
+ struct jump_entry *iter_stop = iter_start + mod->num_jump_entries;
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++;
- }
- }
- }
+ for (iter = iter_start; iter < iter_stop; iter++) {
+ if (within_module_init(iter->code, mod))
+ iter->code = 0;
}
}
@@ -426,59 +305,77 @@ jump_label_module_notify(struct notifier_block *self, unsigned long val,
switch (val) {
case MODULE_STATE_COMING:
jump_label_lock();
- ret = add_jump_label_module(mod);
+ ret = jump_label_add_module(mod);
if (ret)
- remove_jump_label_module(mod);
+ jump_label_del_module(mod);
jump_label_unlock();
break;
case MODULE_STATE_GOING:
jump_label_lock();
- remove_jump_label_module(mod);
+ jump_label_del_module(mod);
jump_label_unlock();
break;
case MODULE_STATE_LIVE:
jump_label_lock();
- remove_jump_label_module_init(mod);
+ jump_label_invalidate_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)
-{
- struct jump_entry *iter;
-
- /* if the module doesn't have jump label entries, just return */
- if (!mod->num_jump_entries)
- return;
-
- iter = mod->jump_entries;
- while (iter < mod->jump_entries + mod->num_jump_entries) {
- arch_jump_label_text_poke_early(iter->code);
- iter++;
- }
+ return notifier_from_errno(ret);
}
struct notifier_block jump_label_module_nb = {
.notifier_call = jump_label_module_notify,
- .priority = 0,
+ .priority = 1, /* higher than tracepoints */
};
-static __init int init_jump_label_module(void)
+static __init int jump_label_init_module(void)
{
return register_module_notifier(&jump_label_module_nb);
}
-early_initcall(init_jump_label_module);
+early_initcall(jump_label_init_module);
#endif /* CONFIG_MODULES */
+/***
+ * 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)
+{
+ int ret = __jump_label_text_reserved(__start___jump_table,
+ __stop___jump_table, start, end);
+
+ if (ret)
+ return ret;
+
+#ifdef CONFIG_MODULES
+ ret = __jump_label_mod_text_reserved(start, end);
+#endif
+ return ret;
+}
+
+static void jump_label_update(struct jump_label_key *key, int enable)
+{
+ struct jump_entry *entry = key->entries;
+
+ /* if there are no users, entry can be NULL */
+ if (entry)
+ __jump_label_update(key, entry, enable);
+
+#ifdef CONFIG_MODULES
+ __jump_label_mod_update(key, enable);
+#endif
+}
+
#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 @@ fail:
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 @@ waitagain:
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);
}
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-20 10:34:02 +0300