From: Frederic Weisbecker Date: Fri, 6 Mar 2009 16:21:49 +0000 (+0100) Subject: tracing/core: drop the old trace_printk() implementation in favour of trace_bprintk() X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=769b0441f438c4bb4872cb8560eb6fe51bcc09ee;p=linux-2.6-omap-h63xx.git tracing/core: drop the old trace_printk() implementation in favour of trace_bprintk() Impact: faster and lighter tracing Now that we have trace_bprintk() which is faster and consume lesser memory than trace_printk() and has the same purpose, we can now drop the old implementation in favour of the binary one from trace_bprintk(), which means we move all the implementation of trace_bprintk() to trace_printk(), so the Api doesn't change except that we must now use trace_seq_bprintk() to print the TRACE_PRINT entries. Some changes result of this: - Previously, trace_bprintk depended of a single tracer and couldn't work without. This tracer has been dropped and the whole implementation of trace_printk() (like the module formats management) is now integrated in the tracing core (comes with CONFIG_TRACING), though we keep the file trace_printk (previously trace_bprintk.c) where we can find the module management. Thus we don't overflow trace.c - changes some parts to use trace_seq_bprintk() to print TRACE_PRINT entries. - change a bit trace_printk/trace_vprintk macros to support non-builtin formats constants, and fix 'const' qualifiers warnings. But this is all transparent for developers. - etc... V2: - Rebase against last changes - Fix mispell on the changelog V3: - Rebase against last changes (moving trace_printk() to kernel.h) Signed-off-by: Frederic Weisbecker Acked-by: Steven Rostedt LKML-Reference: <1236356510-8381-5-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 1cc8ca453a9..e1583f2639b 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -223,31 +223,6 @@ extern int ftrace_make_nop(struct module *mod, */ extern int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr); -#ifdef CONFIG_TRACE_BPRINTK -extern int trace_vbprintk(unsigned long ip, const char *fmt, va_list args); -extern int __trace_bprintk(unsigned long ip, const char *fmt, ...) - __attribute__ ((format (printf, 2, 3))); - -static inline void ____trace_bprintk_check_format(const char *fmt, ...) - __attribute__ ((format (printf, 1, 2))); -static inline void ____trace_bprintk_check_format(const char *fmt, ...) {} -#define __trace_bprintk_check_format(fmt, args...) \ -do { \ - if (0) \ - ____trace_bprintk_check_format(fmt, ##args); \ -} while (0) - -#define trace_bprintk(fmt, args...) \ -do { \ - static char *__attribute__((section("__trace_bprintk_fmt"))) \ - trace_bprintk_fmt = fmt; \ - __trace_bprintk_check_format(fmt, ##args); \ - __trace_bprintk(_THIS_IP_, trace_bprintk_fmt, ##args); \ -} while (0) -#else -#define trace_bprintk trace_printk -#endif - /* May be defined in arch */ extern int ftrace_arch_read_dyn_info(char *buf, int size); diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 7aef15c4645..4e726b9a71e 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -423,6 +423,16 @@ extern void ftrace_off_permanent(void); extern void ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3); +static inline void __attribute__ ((format (printf, 1, 2))) +____trace_printk_check_format(const char *fmt, ...) +{ +} +#define __trace_printk_check_format(fmt, args...) \ +do { \ + if (0) \ + ____trace_printk_check_format(fmt, ##args); \ +} while (0) + /** * trace_printk - printf formatting in the ftrace buffer * @fmt: the printf format for printing @@ -439,13 +449,31 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3); * Please refrain from leaving trace_printks scattered around in * your code. */ -# define trace_printk(fmt...) __trace_printk(_THIS_IP_, fmt) + +#define trace_printk(fmt, args...) \ +do { \ + static const char *trace_printk_fmt \ + __attribute__((section("__trace_printk_fmt"))); \ + trace_printk_fmt = fmt; \ + __trace_printk_check_format(fmt, ##args); \ + __trace_printk(_THIS_IP_, trace_printk_fmt, ##args); \ +} while (0) + extern int __trace_printk(unsigned long ip, const char *fmt, ...) __attribute__ ((format (printf, 2, 3))); -# define ftrace_vprintk(fmt, ap) __trace_printk(_THIS_IP_, fmt, ap) + +#define ftrace_vprintk(fmt, vargs) \ +do { \ + static const char *trace_printk_fmt \ + __attribute__((section("__trace_printk_fmt"))); \ + trace_printk_fmt = fmt; \ + __ftrace_vprintk(_THIS_IP_, trace_printk_fmt, vargs); \ +} while (0) + extern int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap); + extern void ftrace_dump(void); #else static inline void @@ -467,7 +495,7 @@ ftrace_vprintk(const char *fmt, va_list ap) return 0; } static inline void ftrace_dump(void) { } -#endif +#endif /* CONFIG_TRACING */ /* * Display an IP address in readable format. diff --git a/include/linux/module.h b/include/linux/module.h index 8cbec972d8e..22d9878e868 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -329,7 +329,7 @@ struct module unsigned int num_tracepoints; #endif -#ifdef CONFIG_TRACE_BPRINTK +#ifdef CONFIG_TRACING const char **trace_bprintk_fmt_start; unsigned int num_trace_bprintk_fmt; #endif diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index ad8d3617d0a..8e4a2a61cd7 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -52,6 +52,7 @@ config TRACING select STACKTRACE if STACKTRACE_SUPPORT select TRACEPOINTS select NOP_TRACER + select BINARY_PRINTF # # Minimum requirements an architecture has to meet for us to @@ -97,12 +98,6 @@ config FUNCTION_GRAPH_TRACER This is done by setting the current return address on the current task structure into a stack of calls. -config TRACE_BPRINTK - bool "Binary printk for tracing" - default y - depends on TRACING - select BINARY_PRINTF - config IRQSOFF_TRACER bool "Interrupts-off Latency Tracer" default n diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 46557ef4c37..c7a2943796e 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -22,7 +22,7 @@ obj-$(CONFIG_TRACING) += trace.o obj-$(CONFIG_TRACING) += trace_clock.o obj-$(CONFIG_TRACING) += trace_output.o obj-$(CONFIG_TRACING) += trace_stat.o -obj-$(CONFIG_TRACE_BPRINTK) += trace_bprintk.o +obj-$(CONFIG_TRACING) += trace_printk.o obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o obj-$(CONFIG_SYSPROF_TRACER) += trace_sysprof.o obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 46b3cd7a575..cc94f864248 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1169,6 +1169,67 @@ void trace_graph_return(struct ftrace_graph_ret *trace) } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + +/** + * trace_vprintk - write binary msg to tracing buffer + * + */ +int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args) +{ + static DEFINE_SPINLOCK(trace_buf_lock); + static u32 trace_buf[TRACE_BUF_SIZE]; + + struct ring_buffer_event *event; + struct trace_array *tr = &global_trace; + struct trace_array_cpu *data; + struct print_entry *entry; + unsigned long flags; + int resched; + int cpu, len = 0, size, pc; + + if (unlikely(tracing_selftest_running || tracing_disabled)) + return 0; + + /* Don't pollute graph traces with trace_vprintk internals */ + pause_graph_tracing(); + + pc = preempt_count(); + resched = ftrace_preempt_disable(); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; + + if (unlikely(atomic_read(&data->disabled))) + goto out; + + spin_lock_irqsave(&trace_buf_lock, flags); + len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args); + + if (len > TRACE_BUF_SIZE || len < 0) + goto out_unlock; + + size = sizeof(*entry) + sizeof(u32) * len; + event = trace_buffer_lock_reserve(tr, TRACE_PRINT, size, flags, pc); + if (!event) + goto out_unlock; + entry = ring_buffer_event_data(event); + entry->ip = ip; + entry->depth = depth; + entry->fmt = fmt; + + memcpy(entry->buf, trace_buf, sizeof(u32) * len); + ring_buffer_unlock_commit(tr->buffer, event); + +out_unlock: + spin_unlock_irqrestore(&trace_buf_lock, flags); + +out: + ftrace_preempt_enable(resched); + unpause_graph_tracing(); + + return len; +} +EXPORT_SYMBOL_GPL(trace_vprintk); + enum trace_file_type { TRACE_FILE_LAT_FMT = 1, TRACE_FILE_ANNOTATE = 2, @@ -1564,7 +1625,7 @@ static enum print_line_t print_printk_msg_only(struct trace_iterator *iter) trace_assign_type(field, entry); - ret = trace_seq_printf(s, "%s", field->buf); + ret = trace_seq_bprintf(s, field->fmt, field->buf); if (!ret) return TRACE_TYPE_PARTIAL_LINE; @@ -3714,155 +3775,6 @@ static __init int tracer_init_debugfs(void) return 0; } -int trace_vprintk(unsigned long ip, int depth, const char *fmt, va_list args) -{ - static raw_spinlock_t trace_buf_lock = __RAW_SPIN_LOCK_UNLOCKED; - static char trace_buf[TRACE_BUF_SIZE]; - - struct ring_buffer_event *event; - struct trace_array *tr = &global_trace; - struct trace_array_cpu *data; - int cpu, len = 0, size, pc; - struct print_entry *entry; - unsigned long irq_flags; - - if (tracing_disabled || tracing_selftest_running) - return 0; - - pc = preempt_count(); - preempt_disable_notrace(); - cpu = raw_smp_processor_id(); - data = tr->data[cpu]; - - if (unlikely(atomic_read(&data->disabled))) - goto out; - - pause_graph_tracing(); - raw_local_irq_save(irq_flags); - __raw_spin_lock(&trace_buf_lock); - len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); - - len = min(len, TRACE_BUF_SIZE-1); - trace_buf[len] = 0; - - size = sizeof(*entry) + len + 1; - event = trace_buffer_lock_reserve(tr, TRACE_PRINT, size, irq_flags, pc); - if (!event) - goto out_unlock; - entry = ring_buffer_event_data(event); - entry->ip = ip; - entry->depth = depth; - - memcpy(&entry->buf, trace_buf, len); - entry->buf[len] = 0; - ring_buffer_unlock_commit(tr->buffer, event); - - out_unlock: - __raw_spin_unlock(&trace_buf_lock); - raw_local_irq_restore(irq_flags); - unpause_graph_tracing(); - out: - preempt_enable_notrace(); - - return len; -} -EXPORT_SYMBOL_GPL(trace_vprintk); - -int __trace_printk(unsigned long ip, const char *fmt, ...) -{ - int ret; - va_list ap; - - if (!(trace_flags & TRACE_ITER_PRINTK)) - return 0; - - va_start(ap, fmt); - ret = trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap); - va_end(ap); - return ret; -} -EXPORT_SYMBOL_GPL(__trace_printk); - -int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap) -{ - if (!(trace_flags & TRACE_ITER_PRINTK)) - return 0; - - return trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap); -} -EXPORT_SYMBOL_GPL(__ftrace_vprintk); - -/** - * trace_vbprintk - write binary msg to tracing buffer - * - * Caller must insure @fmt are valid when msg is in tracing buffer. - */ -int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) -{ - static DEFINE_SPINLOCK(trace_buf_lock); - static u32 trace_buf[TRACE_BUF_SIZE]; - - struct ring_buffer_event *event; - struct trace_array *tr = &global_trace; - struct trace_array_cpu *data; - struct bprintk_entry *entry; - unsigned long flags; - int resched; - int cpu, len = 0, size, pc; - - if (tracing_disabled || !trace_bprintk_enable) - return 0; - - pc = preempt_count(); - resched = ftrace_preempt_disable(); - cpu = raw_smp_processor_id(); - data = tr->data[cpu]; - - if (unlikely(atomic_read(&data->disabled))) - goto out; - - spin_lock_irqsave(&trace_buf_lock, flags); - len = vbin_printf(trace_buf, TRACE_BUF_SIZE, fmt, args); - - if (len > TRACE_BUF_SIZE || len < 0) - goto out_unlock; - - size = sizeof(*entry) + sizeof(u32) * len; - event = trace_buffer_lock_reserve(tr, TRACE_BPRINTK, size, flags, pc); - if (!event) - goto out_unlock; - entry = ring_buffer_event_data(event); - entry->ip = ip; - entry->fmt = fmt; - - memcpy(entry->buf, trace_buf, sizeof(u32) * len); - ring_buffer_unlock_commit(tr->buffer, event); - -out_unlock: - spin_unlock_irqrestore(&trace_buf_lock, flags); - -out: - ftrace_preempt_enable(resched); - - return len; -} -EXPORT_SYMBOL_GPL(trace_vbprintk); - -int __trace_bprintk(unsigned long ip, const char *fmt, ...) -{ - int ret; - va_list ap; - - if (!fmt) - return 0; - - va_start(ap, fmt); - ret = trace_vbprintk(ip, fmt, ap); - va_end(ap); - return ret; -} -EXPORT_SYMBOL_GPL(__trace_bprintk); - static int trace_panic_handler(struct notifier_block *this, unsigned long event, void *unused) { diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 0f5077f8f95..6140922392c 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -20,7 +20,6 @@ enum trace_type { TRACE_WAKE, TRACE_STACK, TRACE_PRINT, - TRACE_BPRINTK, TRACE_SPECIAL, TRACE_MMIO_RW, TRACE_MMIO_MAP, @@ -120,16 +119,10 @@ struct userstack_entry { */ struct print_entry { struct trace_entry ent; - unsigned long ip; + unsigned long ip; int depth; - char buf[]; -}; - -struct bprintk_entry { - struct trace_entry ent; - unsigned long ip; - const char *fmt; - u32 buf[]; + const char *fmt; + u32 buf[]; }; #ifdef CONFIG_TRACE_BPRINTK extern int trace_bprintk_enable; @@ -296,7 +289,6 @@ extern void __ftrace_bad_type(void); IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \ IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\ IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \ - IF_ASSIGN(var, ent, struct bprintk_entry, TRACE_BPRINTK);\ IF_ASSIGN(var, ent, struct special_entry, 0); \ IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \ TRACE_MMIO_RW); \ diff --git a/kernel/trace/trace_functions_graph.c b/kernel/trace/trace_functions_graph.c index e527f2f66c7..453ebd3b636 100644 --- a/kernel/trace/trace_functions_graph.c +++ b/kernel/trace/trace_functions_graph.c @@ -742,7 +742,11 @@ print_graph_comment(struct print_entry *trace, struct trace_seq *s, } /* The comment */ - ret = trace_seq_printf(s, "/* %s", trace->buf); + ret = trace_seq_printf(s, "/* "); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + ret = trace_seq_bprintf(s, trace->fmt, trace->buf); if (!ret) return TRACE_TYPE_PARTIAL_LINE; diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index c401b908e80..23e346a734c 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -254,15 +254,18 @@ static enum print_line_t mmio_print_mark(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; struct print_entry *print = (struct print_entry *)entry; - const char *msg = print->buf; struct trace_seq *s = &iter->seq; unsigned long long t = ns2usecs(iter->ts); - unsigned long usec_rem = do_div(t, 1000000ULL); + unsigned long usec_rem = do_div(t, USEC_PER_SEC); unsigned secs = (unsigned long)t; int ret; /* The trailing newline must be in the message. */ - ret = trace_seq_printf(s, "MARK %u.%06lu %s", secs, usec_rem, msg); + ret = trace_seq_printf(s, "MARK %u.%06lu ", secs, usec_rem); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + ret = trace_seq_bprintf(s, print->fmt, print->buf); if (!ret) return TRACE_TYPE_PARTIAL_LINE; diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 4ab71201862..ef8fd661b21 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -53,8 +53,7 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...) return len; } -static int -trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary) +int trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary) { int len = (PAGE_SIZE - 1) - s->len; int ret; @@ -834,54 +833,12 @@ static struct trace_event trace_user_stack_event = { }; /* TRACE_PRINT */ -static enum print_line_t trace_print_print(struct trace_iterator *iter, - int flags) -{ - struct print_entry *field; - struct trace_seq *s = &iter->seq; - - trace_assign_type(field, iter->ent); - - if (!seq_print_ip_sym(s, field->ip, flags)) - goto partial; - - if (!trace_seq_printf(s, ": %s", field->buf)) - goto partial; - - return TRACE_TYPE_HANDLED; - - partial: - return TRACE_TYPE_PARTIAL_LINE; -} - -static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags) -{ - struct print_entry *field; - - trace_assign_type(field, iter->ent); - - if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf)) - goto partial; - - return TRACE_TYPE_HANDLED; - - partial: - return TRACE_TYPE_PARTIAL_LINE; -} - -static struct trace_event trace_print_event = { - .type = TRACE_PRINT, - .trace = trace_print_print, - .raw = trace_print_raw, -}; - -/* TRACE_BPRINTK */ static enum print_line_t -trace_bprintk_print(struct trace_iterator *iter, int flags) +trace_print_print(struct trace_iterator *iter, int flags) { struct trace_entry *entry = iter->ent; struct trace_seq *s = &iter->seq; - struct bprintk_entry *field; + struct print_entry *field; trace_assign_type(field, entry); @@ -900,14 +857,13 @@ trace_bprintk_print(struct trace_iterator *iter, int flags) return TRACE_TYPE_PARTIAL_LINE; } -static enum print_line_t -trace_bprintk_raw(struct trace_iterator *iter, int flags) + +static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags) { - struct trace_entry *entry = iter->ent; + struct print_entry *field; struct trace_seq *s = &iter->seq; - struct bprintk_entry *field; - trace_assign_type(field, entry); + trace_assign_type(field, iter->ent); if (!trace_seq_printf(s, ": %lx : ", field->ip)) goto partial; @@ -921,12 +877,11 @@ trace_bprintk_raw(struct trace_iterator *iter, int flags) return TRACE_TYPE_PARTIAL_LINE; } -static struct trace_event trace_bprintk_event = { - .type = TRACE_BPRINTK, - .trace = trace_bprintk_print, - .raw = trace_bprintk_raw, - .hex = trace_nop_print, - .binary = trace_nop_print, + +static struct trace_event trace_print_event = { + .type = TRACE_PRINT, + .trace = trace_print_print, + .raw = trace_print_raw, }; static struct trace_event *events[] __initdata = { @@ -937,7 +892,6 @@ static struct trace_event *events[] __initdata = { &trace_stack_event, &trace_user_stack_event, &trace_print_event, - &trace_bprintk_event, NULL }; diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h index 8a34d688ed6..3b90e6ade1a 100644 --- a/kernel/trace/trace_output.h +++ b/kernel/trace/trace_output.h @@ -18,6 +18,8 @@ struct trace_event { extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...) __attribute__ ((format (printf, 2, 3))); extern int +trace_seq_bprintf(struct trace_seq *s, const char *fmt, const u32 *binary); +extern int seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags); extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, diff --git a/kernel/trace/trace_bprintk.c b/kernel/trace/trace_printk.c similarity index 66% rename from kernel/trace/trace_bprintk.c rename to kernel/trace/trace_printk.c index f4c245a5cd3..a50aea22e92 100644 --- a/kernel/trace/trace_bprintk.c +++ b/kernel/trace/trace_printk.c @@ -21,31 +21,20 @@ #ifdef CONFIG_MODULES -/* binary printk basic */ -static DEFINE_MUTEX(btrace_mutex); /* - * modules trace_bprintk()'s formats are autosaved in struct trace_bprintk_fmt + * modules trace_printk()'s formats are autosaved in struct trace_bprintk_fmt * which are queued on trace_bprintk_fmt_list. */ static LIST_HEAD(trace_bprintk_fmt_list); +/* serialize accesses to trace_bprintk_fmt_list */ +static DEFINE_MUTEX(btrace_mutex); + struct trace_bprintk_fmt { struct list_head list; char fmt[0]; }; - -static inline void lock_btrace(void) -{ - mutex_lock(&btrace_mutex); -} - -static inline void unlock_btrace(void) -{ - mutex_unlock(&btrace_mutex); -} - - static inline struct trace_bprintk_fmt *lookup_format(const char *fmt) { struct trace_bprintk_fmt *pos; @@ -60,7 +49,8 @@ static void hold_module_trace_bprintk_format(const char **start, const char **end) { const char **iter; - lock_btrace(); + + mutex_lock(&btrace_mutex); for (iter = start; iter < end; iter++) { struct trace_bprintk_fmt *tb_fmt = lookup_format(*iter); if (tb_fmt) { @@ -77,7 +67,7 @@ void hold_module_trace_bprintk_format(const char **start, const char **end) } else *iter = NULL; } - unlock_btrace(); + mutex_unlock(&btrace_mutex); } static int module_trace_bprintk_format_notify(struct notifier_block *self, @@ -109,46 +99,40 @@ struct notifier_block module_trace_bprintk_format_nb = { .notifier_call = module_trace_bprintk_format_notify, }; -/* events tracer */ -int trace_bprintk_enable; +int __trace_printk(unsigned long ip, const char *fmt, ...) + { + int ret; + va_list ap; -static void start_bprintk_trace(struct trace_array *tr) -{ - tracing_reset_online_cpus(tr); - trace_bprintk_enable = 1; -} + if (unlikely(!fmt)) + return 0; -static void stop_bprintk_trace(struct trace_array *tr) -{ - trace_bprintk_enable = 0; - tracing_reset_online_cpus(tr); + if (!(trace_flags & TRACE_ITER_PRINTK)) + return 0; + + va_start(ap, fmt); + ret = trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap); + va_end(ap); + return ret; } +EXPORT_SYMBOL_GPL(__trace_printk); -static int init_bprintk_trace(struct trace_array *tr) -{ - start_bprintk_trace(tr); - return 0; +int __ftrace_vprintk(unsigned long ip, const char *fmt, va_list ap) + { + if (unlikely(!fmt)) + return 0; + + if (!(trace_flags & TRACE_ITER_PRINTK)) + return 0; + + return trace_vprintk(ip, task_curr_ret_stack(current), fmt, ap); } +EXPORT_SYMBOL_GPL(__ftrace_vprintk); -static struct tracer bprintk_trace __read_mostly = -{ - .name = "events", - .init = init_bprintk_trace, - .reset = stop_bprintk_trace, - .start = start_bprintk_trace, - .stop = stop_bprintk_trace, -}; -static __init int init_bprintk(void) +static __init int init_trace_printk(void) { - int ret = register_module_notifier(&module_trace_bprintk_format_nb); - if (ret) - return ret; - - ret = register_tracer(&bprintk_trace); - if (ret) - unregister_module_notifier(&module_trace_bprintk_format_nb); - return ret; + return register_module_notifier(&module_trace_bprintk_format_nb); } -device_initcall(init_bprintk); +early_initcall(init_trace_printk);