tracectl cleanup v3
[ust.git] / libust / serialize.c
index b1859ed9a8095f63bda857a72dd14ac1d492a52c..bd947ab1f90d9cd1358bae1538d0f80de2429e62 100644 (file)
  * va_list * to ltt_vtrace.
  */
 
+#define _GNU_SOURCE
+#include <unistd.h>
+#include <sys/syscall.h>
 #include <stdarg.h>
-//ust// #include <linux/ctype.h>
-//ust// #include <linux/string.h>
-//ust// #include <linux/module.h>
-//ust// #include <linux/ltt-tracer.h>
 #include <string.h>
 #include <stdint.h>
 #include <stdio.h>
 
-#include <ust/kernelcompat.h>
 #define _LGPL_SOURCE
 #include <urcu-bp.h>
 #include <urcu/rculist.h>
 
-#include "relay.h"
+#include <ust/core.h>
+#include <ust/clock.h>
+#include "buffers.h"
 #include "tracer.h"
-//#include "list.h"
 #include "usterr.h"
+#include "ust_snprintf.h"
+
+/*
+ * Because UST core defines a non-const PAGE_SIZE, define PAGE_SIZE_STATIC here.
+ * It is just an approximation for the tracer stack.
+ */
+#define PAGE_SIZE_STATIC       4096
 
 enum ltt_type {
        LTT_TYPE_SIGNED_INT,
@@ -50,6 +56,16 @@ enum ltt_type {
        LTT_TYPE_NONE,
 };
 
+/*
+ * Special stack for the tracer. Keeps serialization offsets for each field.
+ * Per-thread. Deals with reentrancy from signals by simply ensuring that
+ * interrupting signals put the stack back to its original position.
+ */
+#define TRACER_STACK_LEN       (PAGE_SIZE_STATIC / sizeof(unsigned long))
+static unsigned long __thread tracer_stack[TRACER_STACK_LEN];
+
+static unsigned int __thread tracer_stack_pos;
+
 #define LTT_ATTRIBUTE_NETWORK_BYTE_ORDER (1<<1)
 
 /*
@@ -252,8 +268,9 @@ parse_end:
  * Field width and precision are *not* supported.
  * %n not supported.
  */
-static inline const char *parse_c_type(const char *fmt,
-               char *c_size, enum ltt_type *c_type)
+static inline
+const char *parse_c_type(const char *fmt, char *c_size, enum ltt_type *c_type,
+                        char *outfmt)
 {
        int qualifier;          /* 'h', 'l', or 'L' for integer fields */
                                /* 'z' support added 23/7/1999 S.H.    */
@@ -285,6 +302,13 @@ repeat:
                }
        }
 
+       if (outfmt) {
+               if (qualifier != -1)
+                       *outfmt++ = (char)qualifier;
+               *outfmt++ = *fmt;
+               *outfmt = 0;
+       }
+
        switch (*fmt) {
        case 'c':
                *c_type = LTT_TYPE_UNSIGNED_INT;
@@ -337,11 +361,13 @@ parse_end:
        return fmt;
 }
 
-static inline size_t serialize_trace_data(struct rchan_buf *buf,
+static inline size_t serialize_trace_data(struct ust_buffer *buf,
                size_t buf_offset,
                char trace_size, enum ltt_type trace_type,
                char c_size, enum ltt_type c_type,
-               int *largest_align, va_list *args)
+               unsigned int *stack_pos_ctx,
+               int *largest_align,
+               va_list *args)
 {
        union {
                unsigned long v_ulong;
@@ -378,16 +404,13 @@ static inline size_t serialize_trace_data(struct rchan_buf *buf,
        case LTT_TYPE_UNSIGNED_INT:
                switch (c_size) {
                case 1:
-                       tmp.v_ulong = (unsigned long)(uint8_t)
-                                       va_arg(*args, unsigned int);
+                       tmp.v_ulong = (unsigned long)(uint8_t)va_arg(*args, unsigned int);
                        break;
                case 2:
-                       tmp.v_ulong = (unsigned long)(uint16_t)
-                                       va_arg(*args, unsigned int);
+                       tmp.v_ulong = (unsigned long)(uint16_t)va_arg(*args, unsigned int);
                        break;
                case 4:
-                       tmp.v_ulong = (unsigned long)(uint32_t)
-                                       va_arg(*args, unsigned int);
+                       tmp.v_ulong = (unsigned long)(uint32_t)va_arg(*args, unsigned int);
                        break;
                case 8:
                        tmp.v_uint64 = va_arg(*args, uint64_t);
@@ -400,10 +423,20 @@ static inline size_t serialize_trace_data(struct rchan_buf *buf,
                tmp.v_string.s = va_arg(*args, const char *);
                if ((unsigned long)tmp.v_string.s < PAGE_SIZE)
                        tmp.v_string.s = "<NULL>";
-               tmp.v_string.len = strlen(tmp.v_string.s)+1;
+               if (!buf) {
+                       /*
+                        * Reserve tracer stack entry.
+                        */
+                       tracer_stack_pos++;
+                       assert(tracer_stack_pos <= TRACER_STACK_LEN);
+                       barrier();
+                       tracer_stack[*stack_pos_ctx] =
+                                       strlen(tmp.v_string.s) + 1;
+               }
+               tmp.v_string.len = tracer_stack[(*stack_pos_ctx)++];
                if (buf)
-                       ltt_relay_write(buf, buf_offset, tmp.v_string.s,
-                               tmp.v_string.len);
+                       ust_buffers_strncpy(buf, buf_offset, tmp.v_string.s,
+                                           tmp.v_string.len);
                buf_offset += tmp.v_string.len;
                goto copydone;
        default:
@@ -430,31 +463,31 @@ static inline size_t serialize_trace_data(struct rchan_buf *buf,
                        switch (trace_size) {
                        case 1:
                                if (c_size == 8)
-                                       ltt_relay_write(buf, buf_offset,
+                                       ust_buffers_write(buf, buf_offset,
                                        (uint8_t[]){ (uint8_t)tmp.v_uint64 },
                                        sizeof(uint8_t));
                                else
-                                       ltt_relay_write(buf, buf_offset,
+                                       ust_buffers_write(buf, buf_offset,
                                        (uint8_t[]){ (uint8_t)tmp.v_ulong },
                                        sizeof(uint8_t));
                                break;
                        case 2:
                                if (c_size == 8)
-                                       ltt_relay_write(buf, buf_offset,
+                                       ust_buffers_write(buf, buf_offset,
                                        (uint16_t[]){ (uint16_t)tmp.v_uint64 },
                                        sizeof(uint16_t));
                                else
-                                       ltt_relay_write(buf, buf_offset,
+                                       ust_buffers_write(buf, buf_offset,
                                        (uint16_t[]){ (uint16_t)tmp.v_ulong },
                                        sizeof(uint16_t));
                                break;
                        case 4:
                                if (c_size == 8)
-                                       ltt_relay_write(buf, buf_offset,
+                                       ust_buffers_write(buf, buf_offset,
                                        (uint32_t[]){ (uint32_t)tmp.v_uint64 },
                                        sizeof(uint32_t));
                                else
-                                       ltt_relay_write(buf, buf_offset,
+                                       ust_buffers_write(buf, buf_offset,
                                        (uint32_t[]){ (uint32_t)tmp.v_ulong },
                                        sizeof(uint32_t));
                                break;
@@ -463,7 +496,7 @@ static inline size_t serialize_trace_data(struct rchan_buf *buf,
                                 * c_size cannot be other than 8 here because
                                 * trace_size > 4.
                                 */
-                               ltt_relay_write(buf, buf_offset,
+                               ust_buffers_write(buf, buf_offset,
                                (uint64_t[]){ (uint64_t)tmp.v_uint64 },
                                sizeof(uint64_t));
                                break;
@@ -480,12 +513,12 @@ static inline size_t serialize_trace_data(struct rchan_buf *buf,
                if (buf) {
                        switch (trace_type) {
                        case LTT_TYPE_SIGNED_INT:
-                               ltt_relay_write(buf, buf_offset,
+                               ust_buffers_write(buf, buf_offset,
                                        (int64_t[]){ (int64_t)tmp.v_ulong },
                                        sizeof(int64_t));
                                break;
                        case LTT_TYPE_UNSIGNED_INT:
-                               ltt_relay_write(buf, buf_offset,
+                               ust_buffers_write(buf, buf_offset,
                                        (uint64_t[]){ (uint64_t)tmp.v_ulong },
                                        sizeof(uint64_t));
                                break;
@@ -501,95 +534,11 @@ copydone:
        return buf_offset;
 }
 
-static notrace void skip_space(const char **ps)
-{
-       while(**ps == ' ')
-               (*ps)++;
-}
-
-static notrace void copy_token(char **out, const char **in)
-{
-       while(**in != ' ' && **in != '\0') {
-               **out = **in;
-               (*out)++;
-               (*in)++;
-       }
-}
-
-/* serialize_to_text
- *
- * Given a format string and a va_list of arguments, convert them to a
- * human-readable string.
- *
- * @outbuf: the buffer to output the string to
- * @bufsize: the max size that can be used in outbuf
- * @fmt: the marker format string
- * @ap: a va_list that contains the arguments corresponding to fmt
- *
- * Return value: the number of chars that have been put in outbuf, excluding
- * the final \0, or, if the buffer was too small, the number of chars that
- * would have been written in outbuf if it had been large enough.
- *
- * outbuf may be NULL. The return value may then be used be allocate an
- * appropriate outbuf.
- *
- */
-
-notrace
-int serialize_to_text(char *outbuf, int bufsize, const char *fmt, va_list ap)
-{
-       int fmt_len = strlen(fmt);
-       char *new_fmt = alloca(fmt_len + 1);
-       const char *orig_fmt_p = fmt;
-       char *new_fmt_p = new_fmt;
-       char false_buf;
-       int result;
-       enum { none, cfmt, tracefmt, argname } prev_token = none;
-
-       while(*orig_fmt_p != '\0') {
-               if(*orig_fmt_p == '%') {
-                       prev_token = cfmt;
-                       copy_token(&new_fmt_p, &orig_fmt_p);
-               }
-               else if(*orig_fmt_p == '#') {
-                       prev_token = tracefmt;
-                       do {
-                               orig_fmt_p++;
-                       } while(*orig_fmt_p != ' ' && *orig_fmt_p != '\0');
-               }
-               else if(*orig_fmt_p == ' ') {
-                       if(prev_token == argname) {
-                               *new_fmt_p = '=';
-                               new_fmt_p++;
-                       }
-                       else if(prev_token == cfmt) {
-                               *new_fmt_p = ' ';
-                               new_fmt_p++;
-                       }
-
-                       skip_space(&orig_fmt_p);
-               }
-               else {
-                       prev_token = argname;
-                       copy_token(&new_fmt_p, &orig_fmt_p);
-               }
-       }
-
-       *new_fmt_p = '\0';
-
-       if(outbuf == NULL) {
-               /* use this false_buffer for compatibility with pre-C99 */
-               outbuf = &false_buf;
-               bufsize = 1;
-       }
-       result = vsnprintf(outbuf, bufsize, new_fmt, ap);
-
-       return result;
-}
-
-notrace size_t ltt_serialize_data(struct rchan_buf *buf, size_t buf_offset,
+notrace size_t ltt_serialize_data(struct ust_buffer *buf, size_t buf_offset,
                        struct ltt_serialize_closure *closure,
-                       void *serialize_private, int *largest_align,
+                       void *serialize_private,
+                       unsigned int stack_pos_ctx,
+                       int *largest_align,
                        const char *fmt, va_list *args)
 {
        char trace_size = 0, c_size = 0;        /*
@@ -614,7 +563,7 @@ notrace size_t ltt_serialize_data(struct rchan_buf *buf, size_t buf_offset,
                        ++fmt;                  /* skip first '%' */
                        if (*fmt == '%')        /* Escaped %% */
                                break;
-                       fmt = parse_c_type(fmt, &c_size, &c_type);
+                       fmt = parse_c_type(fmt, &c_size, &c_type, NULL);
                        /*
                         * Output c types if no trace types has been
                         * specified.
@@ -629,7 +578,9 @@ notrace size_t ltt_serialize_data(struct rchan_buf *buf, size_t buf_offset,
                        buf_offset = serialize_trace_data(buf,
                                                buf_offset, trace_size,
                                                trace_type, c_size, c_type,
-                                               largest_align, args);
+                                               &stack_pos_ctx,
+                                               largest_align,
+                                               args);
                        trace_size = 0;
                        c_size = 0;
                        trace_type = LTT_TYPE_NONE;
@@ -647,25 +598,29 @@ notrace size_t ltt_serialize_data(struct rchan_buf *buf, size_t buf_offset,
  * Assume that the padding for alignment starts at a sizeof(void *) address.
  */
 static notrace size_t ltt_get_data_size(struct ltt_serialize_closure *closure,
-                               void *serialize_private, int *largest_align,
+                               void *serialize_private,
+                               unsigned int stack_pos_ctx, int *largest_align,
                                const char *fmt, va_list *args)
 {
        ltt_serialize_cb cb = closure->callbacks[0];
        closure->cb_idx = 0;
        return (size_t)cb(NULL, 0, closure, serialize_private,
-                               largest_align, fmt, args);
+                         stack_pos_ctx, largest_align, fmt, args);
 }
 
 static notrace
-void ltt_write_event_data(struct rchan_buf *buf, size_t buf_offset,
+void ltt_write_event_data(struct ust_buffer *buf, size_t buf_offset,
                                struct ltt_serialize_closure *closure,
-                               void *serialize_private, int largest_align,
+                               void *serialize_private,
+                               unsigned int stack_pos_ctx,
+                               int largest_align,
                                const char *fmt, va_list *args)
 {
        ltt_serialize_cb cb = closure->callbacks[0];
        closure->cb_idx = 0;
        buf_offset += ltt_align(buf_offset, largest_align);
-       cb(buf, buf_offset, closure, serialize_private, NULL, fmt, args);
+       cb(buf, buf_offset, closure, serialize_private, stack_pos_ctx, NULL,
+          fmt, args);
 }
 
 
@@ -678,18 +633,18 @@ notrace void ltt_vtrace(const struct marker *mdata, void *probe_data,
        uint16_t eID;
        size_t data_size, slot_size;
        unsigned int chan_index;
-       struct ltt_channel_struct *channel;
-       struct ltt_trace_struct *trace, *dest_trace = NULL;
-       struct rchan_buf *buf;
-       void *transport_data;
+       struct ust_channel *channel;
+       struct ust_trace *trace, *dest_trace = NULL;
+       struct ust_buffer *buf;
        u64 tsc;
        long buf_offset;
        va_list args_copy;
        struct ltt_serialize_closure closure;
        struct ltt_probe_private_data *private_data = call_data;
        void *serialize_private = NULL;
-//ust//        int cpu;
+       int cpu;
        unsigned int rflags;
+       unsigned int stack_pos_ctx;
 
        /*
         * This test is useful for quickly exiting static tracing when no trace
@@ -699,9 +654,12 @@ notrace void ltt_vtrace(const struct marker *mdata, void *probe_data,
                return;
 
        rcu_read_lock(); //ust// rcu_read_lock_sched_notrace();
-//ust//        cpu = smp_processor_id();
-//ust//        __get_cpu_var(ltt_nesting)++;
-       ltt_nesting++;
+       cpu = ust_get_cpu();
+
+       /* Force volatile access. */
+       STORE_SHARED(ltt_nesting, LOAD_SHARED(ltt_nesting) + 1);
+       stack_pos_ctx = tracer_stack_pos;
+       barrier();
 
        pdata = (struct ltt_active_marker *)probe_data;
        eID = mdata->event_id;
@@ -721,7 +679,8 @@ notrace void ltt_vtrace(const struct marker *mdata, void *probe_data,
         */
        largest_align = 1;      /* must be non-zero for ltt_align */
        data_size = ltt_get_data_size(&closure, serialize_private,
-                                       &largest_align, fmt, &args_copy);
+                                     stack_pos_ctx, &largest_align,
+                                     fmt, &args_copy);
        largest_align = min_t(int, largest_align, sizeof(void *));
        va_end(args_copy);
 
@@ -754,33 +713,42 @@ notrace void ltt_vtrace(const struct marker *mdata, void *probe_data,
                if (!channel->active)
                        continue;
 
+               /* If a new cpu was plugged since the trace was started, we did
+                * not add it to the trace, and therefore we write the event to
+                * cpu 0.
+                */
+               if(cpu >= channel->n_cpus) {
+                       cpu = 0;
+               }
+
                /* reserve space : header and data */
-               ret = ltt_reserve_slot(trace, channel, &transport_data,
-                                       data_size, &slot_size, &buf_offset,
-                                       &tsc, &rflags,
-                                       largest_align);
+               ret = ltt_reserve_slot(channel, trace, data_size, largest_align,
+                                       cpu, &buf, &slot_size, &buf_offset,
+                                       &tsc, &rflags);
                if (unlikely(ret < 0))
                        continue; /* buffer full */
 
                va_copy(args_copy, *args);
                /* FIXME : could probably encapsulate transport better. */
 //ust//                buf = ((struct rchan *)channel->trans_channel_data)->buf[cpu];
-               buf = ((struct rchan *)channel->trans_channel_data)->buf;
+               buf = channel->buf[cpu];
                /* Out-of-order write : header and data */
-               buf_offset = ltt_write_event_header(trace,
-                                       channel, buf, buf_offset,
+               buf_offset = ltt_write_event_header(channel, buf, buf_offset,
                                        eID, data_size, tsc, rflags);
                ltt_write_event_data(buf, buf_offset, &closure,
-                                       serialize_private,
-                                       largest_align, fmt, &args_copy);
+                                    serialize_private,
+                                    stack_pos_ctx, largest_align,
+                                    fmt, &args_copy);
                va_end(args_copy);
                /* Out-of-order commit */
-               ltt_commit_slot(channel, &transport_data, buf_offset,
-                               data_size, slot_size);
-               DBG("just commited event at offset %ld and size %zd", buf_offset, slot_size);
+               ltt_commit_slot(channel, buf, buf_offset, data_size, slot_size);
+               DBG("just commited event (%s/%s) at offset %ld and size %zd", mdata->channel, mdata->name, buf_offset, slot_size);
        }
-//ust//        __get_cpu_var(ltt_nesting)--;
-       ltt_nesting--;
+
+       barrier();
+       tracer_stack_pos = stack_pos_ctx;
+       STORE_SHARED(ltt_nesting, LOAD_SHARED(ltt_nesting) - 1);
+
        rcu_read_unlock(); //ust// rcu_read_unlock_sched_notrace();
 }
 
@@ -795,6 +763,88 @@ notrace void ltt_trace(const struct marker *mdata, void *probe_data,
        va_end(args);
 }
 
-//ust// MODULE_LICENSE("GPL");
-//ust// MODULE_AUTHOR("Mathieu Desnoyers");
-//ust// MODULE_DESCRIPTION("Linux Trace Toolkit Next Generation Serializer");
+static notrace void skip_space(const char **ps)
+{
+       while(**ps == ' ')
+               (*ps)++;
+}
+
+static notrace void copy_token(char **out, const char **in)
+{
+       while(**in != ' ' && **in != '\0') {
+               **out = **in;
+               (*out)++;
+               (*in)++;
+       }
+}
+
+/* serialize_to_text
+ *
+ * Given a format string and a va_list of arguments, convert them to a
+ * human-readable string.
+ *
+ * @outbuf: the buffer to output the string to
+ * @bufsize: the max size that can be used in outbuf
+ * @fmt: the marker format string
+ * @ap: a va_list that contains the arguments corresponding to fmt
+ *
+ * Return value: the number of chars that have been put in outbuf, excluding
+ * the final \0, or, if the buffer was too small, the number of chars that
+ * would have been written in outbuf if it had been large enough.
+ *
+ * outbuf may be NULL. The return value may then be used be allocate an
+ * appropriate outbuf.
+ *
+ */
+
+notrace
+int serialize_to_text(char *outbuf, int bufsize, const char *fmt, va_list ap)
+{
+       int fmt_len = strlen(fmt);
+       char *new_fmt = alloca(fmt_len + 1);
+       const char *orig_fmt_p = fmt;
+       char *new_fmt_p = new_fmt;
+       char false_buf;
+       int result;
+       enum { none, cfmt, tracefmt, argname } prev_token = none;
+
+       while(*orig_fmt_p != '\0') {
+               if(*orig_fmt_p == '%') {
+                       prev_token = cfmt;
+                       copy_token(&new_fmt_p, &orig_fmt_p);
+               }
+               else if(*orig_fmt_p == '#') {
+                       prev_token = tracefmt;
+                       do {
+                               orig_fmt_p++;
+                       } while(*orig_fmt_p != ' ' && *orig_fmt_p != '\0');
+               }
+               else if(*orig_fmt_p == ' ') {
+                       if(prev_token == argname) {
+                               *new_fmt_p = '=';
+                               new_fmt_p++;
+                       }
+                       else if(prev_token == cfmt) {
+                               *new_fmt_p = ' ';
+                               new_fmt_p++;
+                       }
+
+                       skip_space(&orig_fmt_p);
+               }
+               else {
+                       prev_token = argname;
+                       copy_token(&new_fmt_p, &orig_fmt_p);
+               }
+       }
+
+       *new_fmt_p = '\0';
+
+       if(outbuf == NULL) {
+               /* use this false_buffer for compatibility with pre-C99 */
+               outbuf = &false_buf;
+               bufsize = 1;
+       }
+       result = ust_safe_vsnprintf(outbuf, bufsize, new_fmt, ap);
+
+       return result;
+}
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