From: Steven Rostedt <[email protected]> The file trace.c has become a catchall for most things tracing. Start making it smaller by breaking out various aspects into their own files.
Move the functions associated to the trace_printk operations out of trace.c and into trace_printk.c. Signed-off-by: Steven Rostedt (Google) <[email protected]> --- kernel/trace/trace.c | 431 ------------------------------------ kernel/trace/trace.h | 1 + kernel/trace/trace_printk.c | 431 ++++++++++++++++++++++++++++++++++++ 3 files changed, 432 insertions(+), 431 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 3b7fa2699301..f62bbe7d093f 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -539,17 +539,6 @@ struct trace_array *printk_trace = &global_trace; /* List of trace_arrays interested in the top level trace_marker */ static LIST_HEAD(marker_copies); -static __always_inline bool printk_binsafe(struct trace_array *tr) -{ - /* - * The binary format of traceprintk can cause a crash if used - * by a buffer from another boot. Force the use of the - * non binary version of trace_printk if the trace_printk - * buffer is a boot mapped ring buffer. - */ - return !(tr->flags & TRACE_ARRAY_FL_BOOT); -} - static void update_printk_trace(struct trace_array *tr) { if (printk_trace == tr) @@ -1059,108 +1048,6 @@ void tracing_on(void) } EXPORT_SYMBOL_GPL(tracing_on); -int __trace_array_puts(struct trace_array *tr, unsigned long ip, - const char *str, int size) -{ - struct ring_buffer_event *event; - struct trace_buffer *buffer; - struct print_entry *entry; - unsigned int trace_ctx; - int alloc; - - if (!(tr->trace_flags & TRACE_ITER(PRINTK))) - return 0; - - if (unlikely(tracing_selftest_running && - (tr->flags & TRACE_ARRAY_FL_GLOBAL))) - return 0; - - if (unlikely(tracing_disabled)) - return 0; - - alloc = sizeof(*entry) + size + 2; /* possible \n added */ - - trace_ctx = tracing_gen_ctx(); - buffer = tr->array_buffer.buffer; - guard(ring_buffer_nest)(buffer); - event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, - trace_ctx); - if (!event) - return 0; - - entry = ring_buffer_event_data(event); - entry->ip = ip; - - memcpy(&entry->buf, str, size); - - /* Add a newline if necessary */ - if (entry->buf[size - 1] != '\n') { - entry->buf[size] = '\n'; - entry->buf[size + 1] = '\0'; - } else - entry->buf[size] = '\0'; - - __buffer_unlock_commit(buffer, event); - ftrace_trace_stack(tr, buffer, trace_ctx, 4, NULL); - return size; -} -EXPORT_SYMBOL_GPL(__trace_array_puts); - -/** - * __trace_puts - write a constant string into the trace buffer. - * @ip: The address of the caller - * @str: The constant string to write - * @size: The size of the string. - */ -int __trace_puts(unsigned long ip, const char *str, int size) -{ - return __trace_array_puts(printk_trace, ip, str, size); -} -EXPORT_SYMBOL_GPL(__trace_puts); - -/** - * __trace_bputs - write the pointer to a constant string into trace buffer - * @ip: The address of the caller - * @str: The constant string to write to the buffer to - */ -int __trace_bputs(unsigned long ip, const char *str) -{ - struct trace_array *tr = READ_ONCE(printk_trace); - struct ring_buffer_event *event; - struct trace_buffer *buffer; - struct bputs_entry *entry; - unsigned int trace_ctx; - int size = sizeof(struct bputs_entry); - - if (!printk_binsafe(tr)) - return __trace_puts(ip, str, strlen(str)); - - if (!(tr->trace_flags & TRACE_ITER(PRINTK))) - return 0; - - if (unlikely(tracing_selftest_running || tracing_disabled)) - return 0; - - trace_ctx = tracing_gen_ctx(); - buffer = tr->array_buffer.buffer; - - guard(ring_buffer_nest)(buffer); - event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, - trace_ctx); - if (!event) - return 0; - - entry = ring_buffer_event_data(event); - entry->ip = ip; - entry->str = str; - - __buffer_unlock_commit(buffer, event); - ftrace_trace_stack(tr, buffer, trace_ctx, 4, NULL); - - return 1; -} -EXPORT_SYMBOL_GPL(__trace_bputs); - #ifdef CONFIG_TRACER_SNAPSHOT static void tracing_snapshot_instance_cond(struct trace_array *tr, void *cond_data) @@ -3161,324 +3048,6 @@ void trace_last_func_repeats(struct trace_array *tr, __buffer_unlock_commit(buffer, event); } -/* created for use with alloc_percpu */ -struct trace_buffer_struct { - int nesting; - char buffer[4][TRACE_BUF_SIZE]; -}; - -static struct trace_buffer_struct __percpu *trace_percpu_buffer; - -/* - * This allows for lockless recording. If we're nested too deeply, then - * this returns NULL. - */ -static char *get_trace_buf(void) -{ - struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer); - - if (!trace_percpu_buffer || buffer->nesting >= 4) - return NULL; - - buffer->nesting++; - - /* Interrupts must see nesting incremented before we use the buffer */ - barrier(); - return &buffer->buffer[buffer->nesting - 1][0]; -} - -static void put_trace_buf(void) -{ - /* Don't let the decrement of nesting leak before this */ - barrier(); - this_cpu_dec(trace_percpu_buffer->nesting); -} - -static int alloc_percpu_trace_buffer(void) -{ - struct trace_buffer_struct __percpu *buffers; - - if (trace_percpu_buffer) - return 0; - - buffers = alloc_percpu(struct trace_buffer_struct); - if (MEM_FAIL(!buffers, "Could not allocate percpu trace_printk buffer")) - return -ENOMEM; - - trace_percpu_buffer = buffers; - return 0; -} - -static int buffers_allocated; - -void trace_printk_init_buffers(void) -{ - if (buffers_allocated) - return; - - if (alloc_percpu_trace_buffer()) - return; - - /* trace_printk() is for debug use only. Don't use it in production. */ - - pr_warn("\n"); - pr_warn("**********************************************************\n"); - pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); - pr_warn("** **\n"); - pr_warn("** trace_printk() being used. Allocating extra memory. **\n"); - pr_warn("** **\n"); - pr_warn("** This means that this is a DEBUG kernel and it is **\n"); - pr_warn("** unsafe for production use. **\n"); - pr_warn("** **\n"); - pr_warn("** If you see this message and you are not debugging **\n"); - pr_warn("** the kernel, report this immediately to your vendor! **\n"); - pr_warn("** **\n"); - pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); - pr_warn("**********************************************************\n"); - - /* Expand the buffers to set size */ - if (tracing_update_buffers(NULL) < 0) - pr_err("Failed to expand tracing buffers for trace_printk() calls\n"); - else - buffers_allocated = 1; - - /* - * trace_printk_init_buffers() can be called by modules. - * If that happens, then we need to start cmdline recording - * directly here. - */ - if (system_state == SYSTEM_RUNNING) - tracing_start_cmdline_record(); -} -EXPORT_SYMBOL_GPL(trace_printk_init_buffers); - -void trace_printk_start_comm(void) -{ - /* Start tracing comms if trace printk is set */ - if (!buffers_allocated) - return; - tracing_start_cmdline_record(); -} - -static void trace_printk_start_stop_comm(int enabled) -{ - if (!buffers_allocated) - return; - - if (enabled) - tracing_start_cmdline_record(); - else - tracing_stop_cmdline_record(); -} - -/** - * trace_vbprintk - write binary msg to tracing buffer - * @ip: The address of the caller - * @fmt: The string format to write to the buffer - * @args: Arguments for @fmt - */ -int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) -{ - struct ring_buffer_event *event; - struct trace_buffer *buffer; - struct trace_array *tr = READ_ONCE(printk_trace); - struct bprint_entry *entry; - unsigned int trace_ctx; - char *tbuffer; - int len = 0, size; - - if (!printk_binsafe(tr)) - return trace_vprintk(ip, fmt, args); - - if (unlikely(tracing_selftest_running || tracing_disabled)) - return 0; - - /* Don't pollute graph traces with trace_vprintk internals */ - pause_graph_tracing(); - - trace_ctx = tracing_gen_ctx(); - guard(preempt_notrace)(); - - tbuffer = get_trace_buf(); - if (!tbuffer) { - len = 0; - goto out_nobuffer; - } - - len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args); - - if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0) - goto out_put; - - size = sizeof(*entry) + sizeof(u32) * len; - buffer = tr->array_buffer.buffer; - scoped_guard(ring_buffer_nest, buffer) { - event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, - trace_ctx); - if (!event) - goto out_put; - entry = ring_buffer_event_data(event); - entry->ip = ip; - entry->fmt = fmt; - - memcpy(entry->buf, tbuffer, sizeof(u32) * len); - __buffer_unlock_commit(buffer, event); - ftrace_trace_stack(tr, buffer, trace_ctx, 6, NULL); - } -out_put: - put_trace_buf(); - -out_nobuffer: - unpause_graph_tracing(); - - return len; -} -EXPORT_SYMBOL_GPL(trace_vbprintk); - -static __printf(3, 0) -int __trace_array_vprintk(struct trace_buffer *buffer, - unsigned long ip, const char *fmt, va_list args) -{ - struct ring_buffer_event *event; - int len = 0, size; - struct print_entry *entry; - unsigned int trace_ctx; - char *tbuffer; - - if (unlikely(tracing_disabled)) - return 0; - - /* Don't pollute graph traces with trace_vprintk internals */ - pause_graph_tracing(); - - trace_ctx = tracing_gen_ctx(); - guard(preempt_notrace)(); - - - tbuffer = get_trace_buf(); - if (!tbuffer) { - len = 0; - goto out_nobuffer; - } - - len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); - - size = sizeof(*entry) + len + 1; - scoped_guard(ring_buffer_nest, buffer) { - event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, - trace_ctx); - if (!event) - goto out; - entry = ring_buffer_event_data(event); - entry->ip = ip; - - memcpy(&entry->buf, tbuffer, len + 1); - __buffer_unlock_commit(buffer, event); - ftrace_trace_stack(printk_trace, buffer, trace_ctx, 6, NULL); - } -out: - put_trace_buf(); - -out_nobuffer: - unpause_graph_tracing(); - - return len; -} - -int trace_array_vprintk(struct trace_array *tr, - unsigned long ip, const char *fmt, va_list args) -{ - if (tracing_selftest_running && (tr->flags & TRACE_ARRAY_FL_GLOBAL)) - return 0; - - return __trace_array_vprintk(tr->array_buffer.buffer, ip, fmt, args); -} - -/** - * trace_array_printk - Print a message to a specific instance - * @tr: The instance trace_array descriptor - * @ip: The instruction pointer that this is called from. - * @fmt: The format to print (printf format) - * - * If a subsystem sets up its own instance, they have the right to - * printk strings into their tracing instance buffer using this - * function. Note, this function will not write into the top level - * buffer (use trace_printk() for that), as writing into the top level - * buffer should only have events that can be individually disabled. - * trace_printk() is only used for debugging a kernel, and should not - * be ever incorporated in normal use. - * - * trace_array_printk() can be used, as it will not add noise to the - * top level tracing buffer. - * - * Note, trace_array_init_printk() must be called on @tr before this - * can be used. - */ -int trace_array_printk(struct trace_array *tr, - unsigned long ip, const char *fmt, ...) -{ - int ret; - va_list ap; - - if (!tr) - return -ENOENT; - - /* This is only allowed for created instances */ - if (tr->flags & TRACE_ARRAY_FL_GLOBAL) - return 0; - - if (!(tr->trace_flags & TRACE_ITER(PRINTK))) - return 0; - - va_start(ap, fmt); - ret = trace_array_vprintk(tr, ip, fmt, ap); - va_end(ap); - return ret; -} -EXPORT_SYMBOL_GPL(trace_array_printk); - -/** - * trace_array_init_printk - Initialize buffers for trace_array_printk() - * @tr: The trace array to initialize the buffers for - * - * As trace_array_printk() only writes into instances, they are OK to - * have in the kernel (unlike trace_printk()). This needs to be called - * before trace_array_printk() can be used on a trace_array. - */ -int trace_array_init_printk(struct trace_array *tr) -{ - if (!tr) - return -ENOENT; - - /* This is only allowed for created instances */ - if (tr->flags & TRACE_ARRAY_FL_GLOBAL) - return -EINVAL; - - return alloc_percpu_trace_buffer(); -} -EXPORT_SYMBOL_GPL(trace_array_init_printk); - -int trace_array_printk_buf(struct trace_buffer *buffer, - unsigned long ip, const char *fmt, ...) -{ - int ret; - va_list ap; - - if (!(printk_trace->trace_flags & TRACE_ITER(PRINTK))) - return 0; - - va_start(ap, fmt); - ret = __trace_array_vprintk(buffer, ip, fmt, ap); - va_end(ap); - return ret; -} - -int trace_vprintk(unsigned long ip, const char *fmt, va_list args) -{ - return trace_array_vprintk(printk_trace, ip, fmt, args); -} -EXPORT_SYMBOL_GPL(trace_vprintk); - static void trace_iterator_increment(struct trace_iterator *iter) { struct ring_buffer_iter *buf_iter = trace_buffer_iter(iter, iter->cpu); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 73a2ab195114..f85c94f2e2d9 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -2135,6 +2135,7 @@ extern const char *__stop___tracepoint_str[]; void trace_printk_control(bool enabled); void trace_printk_start_comm(void); +void trace_printk_start_stop_comm(int enabled); int trace_keep_overwrite(struct tracer *tracer, u64 mask, int set); int set_tracer_flag(struct trace_array *tr, u64 mask, int enabled); diff --git a/kernel/trace/trace_printk.c b/kernel/trace/trace_printk.c index 29f6e95439b6..c9cb74a33b3c 100644 --- a/kernel/trace/trace_printk.c +++ b/kernel/trace/trace_printk.c @@ -376,6 +376,437 @@ static const struct file_operations ftrace_formats_fops = { .release = seq_release, }; +static __always_inline bool printk_binsafe(struct trace_array *tr) +{ + /* + * The binary format of traceprintk can cause a crash if used + * by a buffer from another boot. Force the use of the + * non binary version of trace_printk if the trace_printk + * buffer is a boot mapped ring buffer. + */ + return !(tr->flags & TRACE_ARRAY_FL_BOOT); +} + +int __trace_array_puts(struct trace_array *tr, unsigned long ip, + const char *str, int size) +{ + struct ring_buffer_event *event; + struct trace_buffer *buffer; + struct print_entry *entry; + unsigned int trace_ctx; + int alloc; + + if (!(tr->trace_flags & TRACE_ITER(PRINTK))) + return 0; + + if (unlikely(tracing_selftest_running && + (tr->flags & TRACE_ARRAY_FL_GLOBAL))) + return 0; + + if (unlikely(tracing_disabled)) + return 0; + + alloc = sizeof(*entry) + size + 2; /* possible \n added */ + + trace_ctx = tracing_gen_ctx(); + buffer = tr->array_buffer.buffer; + guard(ring_buffer_nest)(buffer); + event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc, + trace_ctx); + if (!event) + return 0; + + entry = ring_buffer_event_data(event); + entry->ip = ip; + + memcpy(&entry->buf, str, size); + + /* Add a newline if necessary */ + if (entry->buf[size - 1] != '\n') { + entry->buf[size] = '\n'; + entry->buf[size + 1] = '\0'; + } else + entry->buf[size] = '\0'; + + __buffer_unlock_commit(buffer, event); + ftrace_trace_stack(tr, buffer, trace_ctx, 4, NULL); + return size; +} +EXPORT_SYMBOL_GPL(__trace_array_puts); + +/** + * __trace_puts - write a constant string into the trace buffer. + * @ip: The address of the caller + * @str: The constant string to write + * @size: The size of the string. + */ +int __trace_puts(unsigned long ip, const char *str, int size) +{ + return __trace_array_puts(printk_trace, ip, str, size); +} +EXPORT_SYMBOL_GPL(__trace_puts); + +/** + * __trace_bputs - write the pointer to a constant string into trace buffer + * @ip: The address of the caller + * @str: The constant string to write to the buffer to + */ +int __trace_bputs(unsigned long ip, const char *str) +{ + struct trace_array *tr = READ_ONCE(printk_trace); + struct ring_buffer_event *event; + struct trace_buffer *buffer; + struct bputs_entry *entry; + unsigned int trace_ctx; + int size = sizeof(struct bputs_entry); + + if (!printk_binsafe(tr)) + return __trace_puts(ip, str, strlen(str)); + + if (!(tr->trace_flags & TRACE_ITER(PRINTK))) + return 0; + + if (unlikely(tracing_selftest_running || tracing_disabled)) + return 0; + + trace_ctx = tracing_gen_ctx(); + buffer = tr->array_buffer.buffer; + + guard(ring_buffer_nest)(buffer); + event = __trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size, + trace_ctx); + if (!event) + return 0; + + entry = ring_buffer_event_data(event); + entry->ip = ip; + entry->str = str; + + __buffer_unlock_commit(buffer, event); + ftrace_trace_stack(tr, buffer, trace_ctx, 4, NULL); + + return 1; +} +EXPORT_SYMBOL_GPL(__trace_bputs); + +/* created for use with alloc_percpu */ +struct trace_buffer_struct { + int nesting; + char buffer[4][TRACE_BUF_SIZE]; +}; + +static struct trace_buffer_struct __percpu *trace_percpu_buffer; + +/* + * This allows for lockless recording. If we're nested too deeply, then + * this returns NULL. + */ +static char *get_trace_buf(void) +{ + struct trace_buffer_struct *buffer = this_cpu_ptr(trace_percpu_buffer); + + if (!trace_percpu_buffer || buffer->nesting >= 4) + return NULL; + + buffer->nesting++; + + /* Interrupts must see nesting incremented before we use the buffer */ + barrier(); + return &buffer->buffer[buffer->nesting - 1][0]; +} + +static void put_trace_buf(void) +{ + /* Don't let the decrement of nesting leak before this */ + barrier(); + this_cpu_dec(trace_percpu_buffer->nesting); +} + +static int alloc_percpu_trace_buffer(void) +{ + struct trace_buffer_struct __percpu *buffers; + + if (trace_percpu_buffer) + return 0; + + buffers = alloc_percpu(struct trace_buffer_struct); + if (MEM_FAIL(!buffers, "Could not allocate percpu trace_printk buffer")) + return -ENOMEM; + + trace_percpu_buffer = buffers; + return 0; +} + +static int buffers_allocated; + +void trace_printk_init_buffers(void) +{ + if (buffers_allocated) + return; + + if (alloc_percpu_trace_buffer()) + return; + + /* trace_printk() is for debug use only. Don't use it in production. */ + + pr_warn("\n"); + pr_warn("**********************************************************\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("** **\n"); + pr_warn("** trace_printk() being used. Allocating extra memory. **\n"); + pr_warn("** **\n"); + pr_warn("** This means that this is a DEBUG kernel and it is **\n"); + pr_warn("** unsafe for production use. **\n"); + pr_warn("** **\n"); + pr_warn("** If you see this message and you are not debugging **\n"); + pr_warn("** the kernel, report this immediately to your vendor! **\n"); + pr_warn("** **\n"); + pr_warn("** NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE NOTICE **\n"); + pr_warn("**********************************************************\n"); + + /* Expand the buffers to set size */ + if (tracing_update_buffers(NULL) < 0) + pr_err("Failed to expand tracing buffers for trace_printk() calls\n"); + else + buffers_allocated = 1; + + /* + * trace_printk_init_buffers() can be called by modules. + * If that happens, then we need to start cmdline recording + * directly here. + */ + if (system_state == SYSTEM_RUNNING) + tracing_start_cmdline_record(); +} +EXPORT_SYMBOL_GPL(trace_printk_init_buffers); + +void trace_printk_start_comm(void) +{ + /* Start tracing comms if trace printk is set */ + if (!buffers_allocated) + return; + tracing_start_cmdline_record(); +} + +void trace_printk_start_stop_comm(int enabled) +{ + if (!buffers_allocated) + return; + + if (enabled) + tracing_start_cmdline_record(); + else + tracing_stop_cmdline_record(); +} + +/** + * trace_vbprintk - write binary msg to tracing buffer + * @ip: The address of the caller + * @fmt: The string format to write to the buffer + * @args: Arguments for @fmt + */ +int trace_vbprintk(unsigned long ip, const char *fmt, va_list args) +{ + struct ring_buffer_event *event; + struct trace_buffer *buffer; + struct trace_array *tr = READ_ONCE(printk_trace); + struct bprint_entry *entry; + unsigned int trace_ctx; + char *tbuffer; + int len = 0, size; + + if (!printk_binsafe(tr)) + return trace_vprintk(ip, fmt, args); + + if (unlikely(tracing_selftest_running || tracing_disabled)) + return 0; + + /* Don't pollute graph traces with trace_vprintk internals */ + pause_graph_tracing(); + + trace_ctx = tracing_gen_ctx(); + guard(preempt_notrace)(); + + tbuffer = get_trace_buf(); + if (!tbuffer) { + len = 0; + goto out_nobuffer; + } + + len = vbin_printf((u32 *)tbuffer, TRACE_BUF_SIZE/sizeof(int), fmt, args); + + if (len > TRACE_BUF_SIZE/sizeof(int) || len < 0) + goto out_put; + + size = sizeof(*entry) + sizeof(u32) * len; + buffer = tr->array_buffer.buffer; + scoped_guard(ring_buffer_nest, buffer) { + event = __trace_buffer_lock_reserve(buffer, TRACE_BPRINT, size, + trace_ctx); + if (!event) + goto out_put; + entry = ring_buffer_event_data(event); + entry->ip = ip; + entry->fmt = fmt; + + memcpy(entry->buf, tbuffer, sizeof(u32) * len); + __buffer_unlock_commit(buffer, event); + ftrace_trace_stack(tr, buffer, trace_ctx, 6, NULL); + } +out_put: + put_trace_buf(); + +out_nobuffer: + unpause_graph_tracing(); + + return len; +} +EXPORT_SYMBOL_GPL(trace_vbprintk); + +static __printf(3, 0) +int __trace_array_vprintk(struct trace_buffer *buffer, + unsigned long ip, const char *fmt, va_list args) +{ + struct ring_buffer_event *event; + int len = 0, size; + struct print_entry *entry; + unsigned int trace_ctx; + char *tbuffer; + + if (unlikely(tracing_disabled)) + return 0; + + /* Don't pollute graph traces with trace_vprintk internals */ + pause_graph_tracing(); + + trace_ctx = tracing_gen_ctx(); + guard(preempt_notrace)(); + + + tbuffer = get_trace_buf(); + if (!tbuffer) { + len = 0; + goto out_nobuffer; + } + + len = vscnprintf(tbuffer, TRACE_BUF_SIZE, fmt, args); + + size = sizeof(*entry) + len + 1; + scoped_guard(ring_buffer_nest, buffer) { + event = __trace_buffer_lock_reserve(buffer, TRACE_PRINT, size, + trace_ctx); + if (!event) + goto out; + entry = ring_buffer_event_data(event); + entry->ip = ip; + + memcpy(&entry->buf, tbuffer, len + 1); + __buffer_unlock_commit(buffer, event); + ftrace_trace_stack(printk_trace, buffer, trace_ctx, 6, NULL); + } +out: + put_trace_buf(); + +out_nobuffer: + unpause_graph_tracing(); + + return len; +} + +int trace_array_vprintk(struct trace_array *tr, + unsigned long ip, const char *fmt, va_list args) +{ + if (tracing_selftest_running && (tr->flags & TRACE_ARRAY_FL_GLOBAL)) + return 0; + + return __trace_array_vprintk(tr->array_buffer.buffer, ip, fmt, args); +} + +/** + * trace_array_printk - Print a message to a specific instance + * @tr: The instance trace_array descriptor + * @ip: The instruction pointer that this is called from. + * @fmt: The format to print (printf format) + * + * If a subsystem sets up its own instance, they have the right to + * printk strings into their tracing instance buffer using this + * function. Note, this function will not write into the top level + * buffer (use trace_printk() for that), as writing into the top level + * buffer should only have events that can be individually disabled. + * trace_printk() is only used for debugging a kernel, and should not + * be ever incorporated in normal use. + * + * trace_array_printk() can be used, as it will not add noise to the + * top level tracing buffer. + * + * Note, trace_array_init_printk() must be called on @tr before this + * can be used. + */ +int trace_array_printk(struct trace_array *tr, + unsigned long ip, const char *fmt, ...) +{ + int ret; + va_list ap; + + if (!tr) + return -ENOENT; + + /* This is only allowed for created instances */ + if (tr->flags & TRACE_ARRAY_FL_GLOBAL) + return 0; + + if (!(tr->trace_flags & TRACE_ITER(PRINTK))) + return 0; + + va_start(ap, fmt); + ret = trace_array_vprintk(tr, ip, fmt, ap); + va_end(ap); + return ret; +} +EXPORT_SYMBOL_GPL(trace_array_printk); + +/** + * trace_array_init_printk - Initialize buffers for trace_array_printk() + * @tr: The trace array to initialize the buffers for + * + * As trace_array_printk() only writes into instances, they are OK to + * have in the kernel (unlike trace_printk()). This needs to be called + * before trace_array_printk() can be used on a trace_array. + */ +int trace_array_init_printk(struct trace_array *tr) +{ + if (!tr) + return -ENOENT; + + /* This is only allowed for created instances */ + if (tr->flags & TRACE_ARRAY_FL_GLOBAL) + return -EINVAL; + + return alloc_percpu_trace_buffer(); +} +EXPORT_SYMBOL_GPL(trace_array_init_printk); + +int trace_array_printk_buf(struct trace_buffer *buffer, + unsigned long ip, const char *fmt, ...) +{ + int ret; + va_list ap; + + if (!(printk_trace->trace_flags & TRACE_ITER(PRINTK))) + return 0; + + va_start(ap, fmt); + ret = __trace_array_vprintk(buffer, ip, fmt, ap); + va_end(ap); + return ret; +} + +int trace_vprintk(unsigned long ip, const char *fmt, va_list args) +{ + return trace_array_vprintk(printk_trace, ip, fmt, args); +} +EXPORT_SYMBOL_GPL(trace_vprintk); + static __init int init_trace_printk_function_export(void) { int ret; -- 2.51.0
