*
* This is intended as a debugging tool for the developer only.
* Please refrain from leaving trace_printks scattered around in
- * your code.
+ * your code. (Extra memory is used for special buffers that are
+ * allocated when trace_printk() is used)
*/
#define trace_printk(fmt, args...) \
extern __printf(2, 3)
int __trace_printk(unsigned long ip, const char *fmt, ...);
+/**
+ * trace_puts - write a string into the ftrace buffer
+ * @str: the string to record
+ *
+ * Note: __trace_bputs is an internal function for trace_puts and
+ * the @ip is passed in via the trace_puts macro.
+ *
+ * This is similar to trace_printk() but is made for those really fast
+ * paths that a developer wants the least amount of "Heisenbug" affects,
+ * where the processing of the print format is still too much.
+ *
+ * This function allows a kernel developer to debug fast path sections
+ * that printk is not appropriate for. By scattering in various
+ * printk like tracing in the code, a developer can quickly see
+ * where problems are occurring.
+ *
+ * This is intended as a debugging tool for the developer only.
+ * Please refrain from leaving trace_puts scattered around in
+ * your code. (Extra memory is used for special buffers that are
+ * allocated when trace_puts() is used)
+ *
+ * Returns: 0 if nothing was written, positive # if string was.
+ * (1 when __trace_bputs is used, strlen(str) when __trace_puts is used)
+ */
+
+extern int __trace_bputs(unsigned long ip, const char *str);
+extern int __trace_puts(unsigned long ip, const char *str, int size);
+#define trace_puts(str) ({ \
+ static const char *trace_printk_fmt \
+ __attribute__((section("__trace_printk_fmt"))) = \
+ __builtin_constant_p(str) ? str : NULL; \
+ \
+ if (__builtin_constant_p(str)) \
+ __trace_bputs(_THIS_IP_, trace_printk_fmt); \
+ else \
+ __trace_puts(_THIS_IP_, str, strlen(str)); \
+})
+
extern void trace_dump_stack(void);
/*
}
EXPORT_SYMBOL_GPL(tracing_on);
+/**
+ * __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)
+{
+ struct ring_buffer_event *event;
+ struct ring_buffer *buffer;
+ struct print_entry *entry;
+ unsigned long irq_flags;
+ int alloc;
+
+ alloc = sizeof(*entry) + size + 2; /* possible \n added */
+
+ local_save_flags(irq_flags);
+ buffer = global_trace.trace_buffer.buffer;
+ event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, alloc,
+ irq_flags, preempt_count());
+ 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);
+
+ return 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 ring_buffer_event *event;
+ struct ring_buffer *buffer;
+ struct bputs_entry *entry;
+ unsigned long irq_flags;
+ int size = sizeof(struct bputs_entry);
+
+ local_save_flags(irq_flags);
+ buffer = global_trace.trace_buffer.buffer;
+ event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
+ irq_flags, preempt_count());
+ if (!event)
+ return 0;
+
+ entry = ring_buffer_event_data(event);
+ entry->ip = ip;
+ entry->str = str;
+
+ __buffer_unlock_commit(buffer, event);
+
+ return 1;
+}
+EXPORT_SYMBOL_GPL(__trace_bputs);
+
#ifdef CONFIG_TRACER_SNAPSHOT
/**
* trace_snapshot - take a snapshot of the current buffer.
return ret;
}
+ if (iter->ent->type == TRACE_BPUTS &&
+ trace_flags & TRACE_ITER_PRINTK &&
+ trace_flags & TRACE_ITER_PRINTK_MSGONLY)
+ return trace_print_bputs_msg_only(iter);
+
if (iter->ent->type == TRACE_BPRINT &&
trace_flags & TRACE_ITER_PRINTK &&
trace_flags & TRACE_ITER_PRINTK_MSGONLY)
TRACE_GRAPH_ENT,
TRACE_USER_STACK,
TRACE_BLK,
+ TRACE_BPUTS,
__TRACE_LAST_TYPE,
};
IF_ASSIGN(var, ent, struct userstack_entry, TRACE_USER_STACK);\
IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \
IF_ASSIGN(var, ent, struct bprint_entry, TRACE_BPRINT); \
+ IF_ASSIGN(var, ent, struct bputs_entry, TRACE_BPUTS); \
IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \
TRACE_MMIO_RW); \
IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \
__dynamic_array( u32, buf )
),
- F_printk("%08lx fmt:%p",
- __entry->ip, __entry->fmt),
+ F_printk("%pf: %s",
+ (void *)__entry->ip, __entry->fmt),
FILTER_OTHER
);
__dynamic_array( char, buf )
),
- F_printk("%08lx %s",
- __entry->ip, __entry->buf),
+ F_printk("%pf: %s",
+ (void *)__entry->ip, __entry->buf),
+
+ FILTER_OTHER
+);
+
+FTRACE_ENTRY(bputs, bputs_entry,
+
+ TRACE_BPUTS,
+
+ F_STRUCT(
+ __field( unsigned long, ip )
+ __field( const char *, str )
+ ),
+
+ F_printk("%pf: %s",
+ (void *)__entry->ip, __entry->str),
FILTER_OTHER
);
return ret;
}
+enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
+{
+ struct trace_seq *s = &iter->seq;
+ struct trace_entry *entry = iter->ent;
+ struct bputs_entry *field;
+ int ret;
+
+ trace_assign_type(field, entry);
+
+ ret = trace_seq_puts(s, field->str);
+ if (!ret)
+ return TRACE_TYPE_PARTIAL_LINE;
+
+ return TRACE_TYPE_HANDLED;
+}
+
enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
{
struct trace_seq *s = &iter->seq;
.funcs = &trace_user_stack_funcs,
};
+/* TRACE_BPUTS */
+static enum print_line_t
+trace_bputs_print(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct trace_entry *entry = iter->ent;
+ struct trace_seq *s = &iter->seq;
+ struct bputs_entry *field;
+
+ trace_assign_type(field, entry);
+
+ if (!seq_print_ip_sym(s, field->ip, flags))
+ goto partial;
+
+ if (!trace_seq_puts(s, ": "))
+ goto partial;
+
+ if (!trace_seq_puts(s, field->str))
+ goto partial;
+
+ return TRACE_TYPE_HANDLED;
+
+ partial:
+ return TRACE_TYPE_PARTIAL_LINE;
+}
+
+
+static enum print_line_t
+trace_bputs_raw(struct trace_iterator *iter, int flags,
+ struct trace_event *event)
+{
+ struct bputs_entry *field;
+ struct trace_seq *s = &iter->seq;
+
+ trace_assign_type(field, iter->ent);
+
+ if (!trace_seq_printf(s, ": %lx : ", field->ip))
+ goto partial;
+
+ if (!trace_seq_puts(s, field->str))
+ goto partial;
+
+ return TRACE_TYPE_HANDLED;
+
+ partial:
+ return TRACE_TYPE_PARTIAL_LINE;
+}
+
+static struct trace_event_functions trace_bputs_funcs = {
+ .trace = trace_bputs_print,
+ .raw = trace_bputs_raw,
+};
+
+static struct trace_event trace_bputs_event = {
+ .type = TRACE_BPUTS,
+ .funcs = &trace_bputs_funcs,
+};
+
/* TRACE_BPRINT */
static enum print_line_t
trace_bprint_print(struct trace_iterator *iter, int flags,
&trace_wake_event,
&trace_stack_event,
&trace_user_stack_event,
+ &trace_bputs_event,
&trace_bprint_event,
&trace_print_event,
NULL
#include <linux/trace_seq.h>
#include "trace.h"
+extern enum print_line_t
+trace_print_bputs_msg_only(struct trace_iterator *iter);
extern enum print_line_t
trace_print_bprintk_msg_only(struct trace_iterator *iter);
extern enum print_line_t
projects / linux.git / commitdiff