1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright 2023 Google LLC
4 * Written by Simon Glass <sjg@chromium.org>
5 */
6
7 /*
8 * Decode and dump U-Boot trace information into formats that can be used
9 * by trace-cmd, kernelshark or flamegraph.pl
10 *
11 * See doc/develop/trace.rst for more information
12 */
13
14 #include <assert.h>
15 #include <ctype.h>
16 #include <limits.h>
17 #include <regex.h>
18 #include <stdarg.h>
19 #include <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <unistd.h>
23 #include <sys/param.h>
24 #include <sys/types.h>
25
26 #include <compiler.h>
27 #include <trace.h>
28 #include <abuf.h>
29
30 #include <linux/list.h>
31
32 /* Set to 1 to emit version 7 file (currently this doesn't work) */
33 #define VERSION7 0
34
35 /* enable some debug features */
36 #define _DEBUG 0
37
38 /* from linux/kernel.h */
39 #define __ALIGN_MASK(x, mask) (((x) + (mask)) & ~(mask))
40 #define ALIGN(x, a) __ALIGN_MASK((x), (typeof(x))(a) - 1)
41
42 /**
43 * container_of - cast a member of a structure out to the containing structure
44 * @ptr: the pointer to the member.
45 * @type: the type of the container struct this is embedded in.
46 * @member: the name of the member within the struct.
47 *
48 * (this is needed by list.h)
49 */
50 #define container_of(ptr, type, member) ({ \
51 const typeof( ((type *)0)->member ) *__mptr = (ptr); \
52 (type *)( (char *)__mptr - offsetof(type,member) );})
53
54 enum {
55 FUNCF_TRACE = 1 << 0, /* Include this function in trace */
56 TRACE_PAGE_SIZE = 4096, /* Assumed page size for trace */
57 TRACE_PID = 1, /* PID to use for U-Boot */
58 LEN_STACK_SIZE = 4, /* number of nested length fix-ups */
59 TRACE_PAGE_MASK = TRACE_PAGE_SIZE - 1,
60 MAX_STACK_DEPTH = 50, /* Max nested function calls */
61 MAX_LINE_LEN = 500, /* Max characters per line */
62 };
63
64 /**
65 * enum out_format_t - supported output formats
66 *
67 * @OUT_FMT_DEFAULT: Use the default for the output file
68 * @OUT_FMT_FUNCTION: Write ftrace 'function' records
69 * @OUT_FMT_FUNCGRAPH: Write ftrace funcgraph_entry and funcgraph_exit records
70 * @OUT_FMT_FLAMEGRAPH_CALLS: Write a file suitable for flamegraph.pl
71 * @OUT_FMT_FLAMEGRAPH_TIMING: Write a file suitable for flamegraph.pl with the
72 * counts set to the number of microseconds used by each function
73 */
74 enum out_format_t {
75 OUT_FMT_DEFAULT,
76 OUT_FMT_FUNCTION,
77 OUT_FMT_FUNCGRAPH,
78 OUT_FMT_FLAMEGRAPH_CALLS,
79 OUT_FMT_FLAMEGRAPH_TIMING,
80 };
81
82 /* Section types for v7 format (trace-cmd format) */
83 enum {
84 SECTION_OPTIONS,
85 };
86
87 /* Option types (trace-cmd format) */
88 enum {
89 OPTION_DONE,
90 OPTION_DATE,
91 OPTION_CPUSTAT,
92 OPTION_BUFFER,
93 OPTION_TRACECLOCK,
94 OPTION_UNAME,
95 OPTION_HOOK,
96 OPTION_OFFSET,
97 OPTION_CPUCOUNT,
98 OPTION_VERSION,
99 OPTION_PROCMAPS,
100 OPTION_TRACEID,
101 OPTION_TIME_SHIFT,
102 OPTION_GUEST,
103 OPTION_TSC2NSEC,
104 };
105
106 /* types of trace records (trace-cmd format) */
107 enum trace_type {
108 __TRACE_FIRST_TYPE = 0,
109
110 TRACE_FN,
111 TRACE_CTX,
112 TRACE_WAKE,
113 TRACE_STACK,
114 TRACE_PRINT,
115 TRACE_BPRINT,
116 TRACE_MMIO_RW,
117 TRACE_MMIO_MAP,
118 TRACE_BRANCH,
119 TRACE_GRAPH_RET,
120 TRACE_GRAPH_ENT,
121 };
122
123 /**
124 * struct flame_node - a node in the call-stack tree
125 *
126 * Each stack frame detected in the trace is given a node corresponding to a
127 * function call in the call stack. Functions can appear multiple times when
128 * they are called by a different set of parent functions.
129 *
130 * @parent: Parent node (the call stack for the function that called this one)
131 * @child_head: List of children of this node (functions called from here)
132 * @sibling: Next node in the list of children
133 * @func: Function this node refers to (NULL for root node)
134 * @count: Number of times this call-stack occurred
135 * @duration: Number of microseconds taken to run this function, excluding all
136 * of the functions it calls
137 */
138 struct flame_node {
139 struct flame_node *parent;
140 struct list_head child_head;
141 struct list_head sibling_node;
142 struct func_info *func;
143 int count;
144 ulong duration;
145 };
146
147 /**
148 * struct flame_state - state information for building the flame graph
149 *
150 * @node: Current node being processed (corresponds to a function call)
151 * @stack: Stack of call-start time for this function as well as the
152 * accumulated total time of all child calls (so we can subtract them from the
153 * function's call time. This is an 'empty' stack, meaning that @stack_ptr
154 * points to the next available stack position
155 * @stack_ptr: points to first empty position in the stack
156 * @nodes: Number of nodes created (running count)
157 */
158 struct flame_state {
159 struct flame_node *node;
160 struct stack_info {
161 ulong timestamp;
162 ulong child_total;
163 } stack[MAX_STACK_DEPTH];
164 int stack_ptr;
165 int nodes;
166 };
167
168 /**
169 * struct func_info - information recorded for each function
170 *
171 * @offset: Function offset in the image, measured from the text_base
172 * @name: Function name
173 * @code_size: Total code size of the function
174 * @flags: Either 0 or FUNCF_TRACE
175 */
176 struct func_info {
177 unsigned long offset;
178 const char *name;
179 unsigned long code_size;
180 unsigned flags;
181 };
182
183 /**
184 * enum trace_line_type - whether to include or exclude a function
185 *
186 * @TRACE_LINE_INCLUDE: Include the function
187 * @TRACE_LINE_EXCLUDE: Exclude the function
188 */
189 enum trace_line_type {
190 TRACE_LINE_INCLUDE,
191 TRACE_LINE_EXCLUDE,
192 };
193
194 /**
195 * struct trace_configline_info - information about a config-file line
196 *
197 * @next: Next line
198 * @type: Line type
199 * @name: identifier name / wildcard
200 * @regex: Regex to use if name starts with '/'
201 */
202 struct trace_configline_info {
203 struct trace_configline_info *next;
204 enum trace_line_type type;
205 const char *name;
206 regex_t regex;
207 };
208
209 /**
210 * struct tw_len - holds information about a length value that need fix-ups
211 *
212 * This is used to record a placeholder for a u32 or u64 length which is written
213 * to the output file but needs to be updated once the length is actually known
214 *
215 * This allows us to write tw->ptr - @len_base to position @ptr in the file
216 *
217 * @ptr: Position of the length value in the file
218 * @base: Base position for the calculation
219 * @size: Size of the length value, in bytes (4 or 8)
220 */
221 struct tw_len {
222 int ptr;
223 int base;
224 int size;
225 };
226
227 /**
228 * struct twriter - Writer for trace records
229 *
230 * Maintains state used when writing the output file in trace-cmd format
231 *
232 * @ptr: Current file position
233 * @len_stack: Stack of length values that need fixing up
234 * @len: Number of items on @len_stack
235 * @str_buf: Buffer of strings (for v7 format)
236 * @str_ptr: Current write-position in the buffer for strings
237 * @fout: Output file
238 */
239 struct twriter {
240 int ptr;
241 struct tw_len len_stack[LEN_STACK_SIZE];
242 int len_count;
243 struct abuf str_buf;
244 int str_ptr;
245 FILE *fout;
246 };
247
248 /* The contents of the trace config file */
249 struct trace_configline_info *trace_config_head;
250
251 /* list of all functions in System.map file, sorted by offset in the image */
252 struct func_info *func_list;
253
254 int func_count; /* number of functions */
255 struct trace_call *call_list; /* list of all calls in the input trace file */
256 int call_count; /* number of calls */
257 int verbose; /* Verbosity level 0=none, 1=warn, 2=notice, 3=info, 4=debug */
258 ulong text_offset; /* text address of first function */
259 ulong text_base; /* CONFIG_TEXT_BASE from trace file */
260
261 /* debugging helpers */
262 static void outf(int level, const char *fmt, ...)
263 __attribute__ ((format (__printf__, 2, 3)));
264 #define error(fmt, b...) outf(0, fmt, ##b)
265 #define warn(fmt, b...) outf(1, fmt, ##b)
266 #define notice(fmt, b...) outf(2, fmt, ##b)
267 #define info(fmt, b...) outf(3, fmt, ##b)
268 #define debug(fmt, b...) outf(4, fmt, ##b)
269
outf(int level,const char * fmt,...)270 static void outf(int level, const char *fmt, ...)
271 {
272 if (verbose >= level) {
273 va_list args;
274
275 va_start(args, fmt);
276 vfprintf(stderr, fmt, args);
277 va_end(args);
278 }
279 }
280
usage(void)281 static void usage(void)
282 {
283 fprintf(stderr,
284 "Usage: proftool [-cmtv] <cmd> <profdata>\n"
285 "\n"
286 "Commands\n"
287 " dump-ftrace\t\tDump out records in ftrace format for use by trace-cmd\n"
288 " dump-flamegraph\tWrite a file for use with flamegraph.pl\n"
289 "\n"
290 "Options:\n"
291 " -c <cfg>\tSpecify config file\n"
292 " -f <subtype>\tSpecify output subtype\n"
293 " -m <map>\tSpecify Systen.map file\n"
294 " -o <fname>\tSpecify output file\n"
295 " -t <fname>\tSpecify trace data file (from U-Boot 'trace calls')\n"
296 " -v <0-4>\tSpecify verbosity\n"
297 "\n"
298 "Subtypes for dump-ftrace:\n"
299 " function - write function-call records (caller/callee)\n"
300 " funcgraph - write function entry/exit records (graph)\n"
301 "\n"
302 "Subtypes for dump-flamegraph\n"
303 " calls - create a flamegraph of stack frames\n"
304 " timing - create a flamegraph of microseconds for each stack frame\n");
305 exit(EXIT_FAILURE);
306 }
307
308 /**
309 * h_cmp_offset - bsearch() function to compare two functions bny their offset
310 *
311 * @v1: Pointer to first function (struct func_info)
312 * @v2: Pointer to second function (struct func_info)
313 * Returns: < 0 if v1 offset < v2 offset, 0 if equal, > 0 otherwise
314 */
h_cmp_offset(const void * v1,const void * v2)315 static int h_cmp_offset(const void *v1, const void *v2)
316 {
317 const struct func_info *f1 = v1, *f2 = v2;
318
319 return (f1->offset / FUNC_SITE_SIZE) - (f2->offset / FUNC_SITE_SIZE);
320 }
321
322 /**
323 * read_system_map() - read the System.map file to create a list of functions
324 *
325 * This also reads the text_offset value, since we assume that the first text
326 * symbol is at that address
327 *
328 * @fin: File to read
329 * Returns: 0 if OK, non-zero on error
330 */
read_system_map(FILE * fin)331 static int read_system_map(FILE *fin)
332 {
333 unsigned long offset, start = 0;
334 struct func_info *func;
335 char buff[MAX_LINE_LEN];
336 char symtype;
337 char symname[MAX_LINE_LEN + 1];
338 int linenum;
339 int alloced;
340
341 for (linenum = 1, alloced = func_count = 0;; linenum++) {
342 int fields = 0;
343
344 if (fgets(buff, sizeof(buff), fin))
345 fields = sscanf(buff, "%lx %c %100s\n", &offset,
346 &symtype, symname);
347 if (fields == 2) {
348 continue;
349 } else if (feof(fin)) {
350 break;
351 } else if (fields < 2) {
352 error("Map file line %d: invalid format\n", linenum);
353 return 1;
354 }
355
356 /* Must be a text symbol */
357 symtype = tolower(symtype);
358 if (symtype != 't' && symtype != 'w')
359 continue;
360
361 if (func_count == alloced) {
362 alloced += 256;
363 func_list = realloc(func_list,
364 sizeof(struct func_info) * alloced);
365 assert(func_list);
366 }
367 if (!func_count)
368 start = offset;
369
370 func = &func_list[func_count++];
371 memset(func, '\0', sizeof(*func));
372 func->offset = offset - start;
373 func->name = strdup(symname);
374 func->flags = FUNCF_TRACE; /* trace by default */
375
376 /* Update previous function's code size */
377 if (func_count > 1)
378 func[-1].code_size = func->offset - func[-1].offset;
379 }
380 notice("%d functions found in map file, start addr %lx\n", func_count,
381 start);
382 text_offset = start;
383
384 return 0;
385 }
386
read_data(FILE * fin,void * buff,int size)387 static int read_data(FILE *fin, void *buff, int size)
388 {
389 int err;
390
391 err = fread(buff, 1, size, fin);
392 if (!err)
393 return 1;
394 if (err != size) {
395 error("Cannot read trace file at pos %lx\n", ftell(fin));
396 return -1;
397 }
398 return 0;
399 }
400
401 /**
402 * find_func_by_offset() - Look up a function by its offset
403 *
404 * @offset: Offset to search for, from text_base
405 * Returns: function, if found, else NULL
406 *
407 * This does a fast search for a function given its offset from text_base
408 *
409 */
find_func_by_offset(uint offset)410 static struct func_info *find_func_by_offset(uint offset)
411 {
412 struct func_info key, *found;
413
414 key.offset = offset;
415 found = bsearch(&key, func_list, func_count, sizeof(struct func_info),
416 h_cmp_offset);
417
418 return found;
419 }
420
421 /**
422 * find_caller_by_offset() - finds the function which contains the given offset
423 *
424 * @offset: Offset to search for, from text_base
425 * Returns: function, if found, else NULL
426 *
427 * If the offset falls between two functions, then it is assumed to belong to
428 * the first function (with the lowest offset). This is a way of figuring out
429 * which function owns code at a particular offset
430 */
find_caller_by_offset(uint offset)431 static struct func_info *find_caller_by_offset(uint offset)
432 {
433 int low; /* least function that could be a match */
434 int high; /* greated function that could be a match */
435 struct func_info key;
436
437 low = 0;
438 high = func_count - 1;
439 key.offset = offset;
440 while (high > low + 1) {
441 int mid = (low + high) / 2;
442 int result;
443
444 result = h_cmp_offset(&key, &func_list[mid]);
445 if (result > 0)
446 low = mid;
447 else if (result < 0)
448 high = mid;
449 else
450 return &func_list[mid];
451 }
452
453 return low >= 0 ? &func_list[low] : NULL;
454 }
455
456 /**
457 * read_calls() - Read the list of calls from the trace data
458 *
459 * The calls are stored consecutively in the trace output produced by U-Boot
460 *
461 * @fin: File to read from
462 * @count: Number of calls to read
463 * Returns: 0 if OK, -1 on error
464 */
read_calls(FILE * fin,size_t count)465 static int read_calls(FILE *fin, size_t count)
466 {
467 struct trace_call *call_data;
468 int i;
469
470 notice("call count: %zu\n", count);
471 call_list = (struct trace_call *)calloc(count, sizeof(*call_data));
472 if (!call_list) {
473 error("Cannot allocate call_list\n");
474 return -1;
475 }
476 call_count = count;
477
478 call_data = call_list;
479 for (i = 0; i < count; i++, call_data++) {
480 if (read_data(fin, call_data, sizeof(*call_data)))
481 return -1;
482 }
483 return 0;
484 }
485
486 /**
487 * read_trace() - Read the U-Boot trace file
488 *
489 * Read in the calls from the trace file. The function list is ignored at
490 * present
491 *
492 * @fin: File to read
493 * Returns 0 if OK, non-zero on error
494 */
read_trace(FILE * fin)495 static int read_trace(FILE *fin)
496 {
497 struct trace_output_hdr hdr;
498
499 while (!feof(fin)) {
500 int err;
501
502 err = read_data(fin, &hdr, sizeof(hdr));
503 if (err == 1)
504 break; /* EOF */
505 else if (err)
506 return 1;
507 text_base = hdr.text_base;
508
509 switch (hdr.type) {
510 case TRACE_CHUNK_FUNCS:
511 /* Ignored at present */
512 break;
513
514 case TRACE_CHUNK_CALLS:
515 if (read_calls(fin, hdr.rec_count))
516 return 1;
517 break;
518 }
519 }
520 return 0;
521 }
522
523 /**
524 * read_map_file() - Read the System.map file
525 *
526 * This reads the file into the func_list array
527 *
528 * @fname: Filename to read
529 * Returns 0 if OK, non-zero on error
530 */
read_map_file(const char * fname)531 static int read_map_file(const char *fname)
532 {
533 FILE *fmap;
534 int err = 0;
535
536 fmap = fopen(fname, "r");
537 if (!fmap) {
538 error("Cannot open map file '%s'\n", fname);
539 return 1;
540 }
541 if (fmap) {
542 err = read_system_map(fmap);
543 fclose(fmap);
544 }
545 return err;
546 }
547
548 /**
549 * read_trace_file() - Open and read the U-Boot trace file
550 *
551 * Read in the calls from the trace file. The function list is ignored at
552 * present
553 *
554 * @fin: File to read
555 * Returns 0 if OK, non-zero on error
556 */
read_trace_file(const char * fname)557 static int read_trace_file(const char *fname)
558 {
559 FILE *fprof;
560 int err;
561
562 fprof = fopen(fname, "rb");
563 if (!fprof) {
564 error("Cannot open trace data file '%s'\n",
565 fname);
566 return 1;
567 } else {
568 err = read_trace(fprof);
569 fclose(fprof);
570 if (err)
571 return err;
572 }
573 return 0;
574 }
575
regex_report_error(regex_t * regex,int err,const char * op,const char * name)576 static int regex_report_error(regex_t *regex, int err, const char *op,
577 const char *name)
578 {
579 char buf[200];
580
581 regerror(err, regex, buf, sizeof(buf));
582 error("Regex error '%s' in %s '%s'\n", buf, op, name);
583 return -1;
584 }
585
check_trace_config_line(struct trace_configline_info * item)586 static void check_trace_config_line(struct trace_configline_info *item)
587 {
588 struct func_info *func, *end;
589 int err;
590
591 debug("Checking trace config line '%s'\n", item->name);
592 for (func = func_list, end = func + func_count; func < end; func++) {
593 err = regexec(&item->regex, func->name, 0, NULL, 0);
594 debug(" - regex '%s', string '%s': %d\n", item->name,
595 func->name, err);
596 if (err == REG_NOMATCH)
597 continue;
598
599 if (err) {
600 regex_report_error(&item->regex, err, "match",
601 item->name);
602 break;
603 }
604
605 /* It matches, so perform the action */
606 switch (item->type) {
607 case TRACE_LINE_INCLUDE:
608 info(" include %s at %lx\n", func->name,
609 text_offset + func->offset);
610 func->flags |= FUNCF_TRACE;
611 break;
612
613 case TRACE_LINE_EXCLUDE:
614 info(" exclude %s at %lx\n", func->name,
615 text_offset + func->offset);
616 func->flags &= ~FUNCF_TRACE;
617 break;
618 }
619 }
620 }
621
622 /** check_trace_config() - Check trace-config file, reporting any problems */
check_trace_config(void)623 static void check_trace_config(void)
624 {
625 struct trace_configline_info *line;
626
627 for (line = trace_config_head; line; line = line->next)
628 check_trace_config_line(line);
629 }
630
631 /**
632 * read_trace_config() - read the trace-config file
633 *
634 * This file consists of lines like:
635 *
636 * include-func <regex>
637 * exclude-func <regex>
638 *
639 * where <regex> is a regular expression matched against function names. It
640 * allows some functions to be dropped from the trace when producing ftrace
641 * records
642 *
643 * @fin: File to process
644 * Returns: 0 if OK, -1 on error
645 */
read_trace_config(FILE * fin)646 static int read_trace_config(FILE *fin)
647 {
648 char buff[200];
649 int linenum = 0;
650 struct trace_configline_info **tailp = &trace_config_head;
651
652 while (fgets(buff, sizeof(buff), fin)) {
653 int len = strlen(buff);
654 struct trace_configline_info *line;
655 char *saveptr;
656 char *s, *tok;
657 int err;
658
659 linenum++;
660 if (len && buff[len - 1] == '\n')
661 buff[len - 1] = '\0';
662
663 /* skip blank lines and comments */
664 for (s = buff; *s == ' ' || *s == '\t'; s++)
665 ;
666 if (!*s || *s == '#')
667 continue;
668
669 line = (struct trace_configline_info *)calloc(1, sizeof(*line));
670 if (!line) {
671 error("Cannot allocate config line\n");
672 return -1;
673 }
674
675 tok = strtok_r(s, " \t", &saveptr);
676 if (!tok) {
677 error("Invalid trace config data on line %d\n",
678 linenum);
679 return -1;
680 }
681 if (0 == strcmp(tok, "include-func")) {
682 line->type = TRACE_LINE_INCLUDE;
683 } else if (0 == strcmp(tok, "exclude-func")) {
684 line->type = TRACE_LINE_EXCLUDE;
685 } else {
686 error("Unknown command in trace config data line %d\n",
687 linenum);
688 return -1;
689 }
690
691 tok = strtok_r(NULL, " \t", &saveptr);
692 if (!tok) {
693 error("Missing pattern in trace config data line %d\n",
694 linenum);
695 return -1;
696 }
697
698 err = regcomp(&line->regex, tok, REG_NOSUB);
699 if (err) {
700 int r = regex_report_error(&line->regex, err,
701 "compile", tok);
702 free(line);
703 return r;
704 }
705
706 /* link this new one to the end of the list */
707 line->name = strdup(tok);
708 line->next = NULL;
709 *tailp = line;
710 tailp = &line->next;
711 }
712
713 if (!feof(fin)) {
714 error("Cannot read from trace config file at position %ld\n",
715 ftell(fin));
716 return -1;
717 }
718 return 0;
719 }
720
read_trace_config_file(const char * fname)721 static int read_trace_config_file(const char *fname)
722 {
723 FILE *fin;
724 int err;
725
726 fin = fopen(fname, "r");
727 if (!fin) {
728 error("Cannot open trace_config file '%s'\n", fname);
729 return -1;
730 }
731 err = read_trace_config(fin);
732 fclose(fin);
733 return err;
734 }
735
736 /**
737 * tputh() - Write a 16-bit little-endian value to a file
738 *
739 * @fout: File to write to
740 * @val: Value to write
741 * Returns: number of bytes written (2)
742 */
tputh(FILE * fout,unsigned int val)743 static int tputh(FILE *fout, unsigned int val)
744 {
745 fputc(val, fout);
746 fputc(val >> 8, fout);
747
748 return 2;
749 }
750
751 /**
752 * tputl() - Write a 32-bit little-endian value to a file
753 *
754 * @fout: File to write to
755 * @val: Value to write
756 * Returns: number of bytes written (4)
757 */
tputl(FILE * fout,ulong val)758 static int tputl(FILE *fout, ulong val)
759 {
760 fputc(val, fout);
761 fputc(val >> 8, fout);
762 fputc(val >> 16, fout);
763 fputc(val >> 24, fout);
764
765 return 4;
766 }
767
768 /**
769 * tputh() - Write a 64-bit little-endian value to a file
770 *
771 * @fout: File to write to
772 * @val: Value to write
773 * Returns: number of bytes written (8)
774 */
tputq(FILE * fout,unsigned long long val)775 static int tputq(FILE *fout, unsigned long long val)
776 {
777 tputl(fout, val);
778 tputl(fout, val >> 32U);
779
780 return 8;
781 }
782
783 /**
784 * tputh() - Write a string to a file
785 *
786 * The string is written without its terminator
787 *
788 * @fout: File to write to
789 * @val: Value to write
790 * Returns: number of bytes written
791 */
tputs(FILE * fout,const char * str)792 static int tputs(FILE *fout, const char *str)
793 {
794 fputs(str, fout);
795
796 return strlen(str);
797 }
798
799 /**
800 * add_str() - add a name string to the string table
801 *
802 * This is used by the v7 format
803 *
804 * @tw: Writer context
805 * @name: String to write
806 * Returns: Updated value of string pointer, or -1 if out of memory
807 */
add_str(struct twriter * tw,const char * name)808 static int add_str(struct twriter *tw, const char *name)
809 {
810 int str_ptr;
811 int len;
812
813 len = strlen(name) + 1;
814 str_ptr = tw->str_ptr;
815 tw->str_ptr += len;
816
817 if (tw->str_ptr > abuf_size(&tw->str_buf)) {
818 int new_size;
819
820 new_size = ALIGN(tw->str_ptr, 4096);
821 if (!abuf_realloc(&tw->str_buf, new_size))
822 return -1;
823 }
824
825 return str_ptr;
826 }
827
828 /**
829 * push_len() - Push a new length request onto the stack
830 *
831 * @tw: Writer context
832 * @base: Base position of the length calculation
833 * @msg: Indicates the type of caller, for debugging
834 * @size: Size of the length value, either 4 bytes or 8
835 * Returns number of bytes written to the file (=@size on success), -ve on error
836 *
837 * This marks a place where a length must be written, covering data that is
838 * about to be written. It writes a placeholder value.
839 *
840 * Once the data is written, calling pop_len() will update the placeholder with
841 * the correct length based on how many bytes have been written
842 */
push_len(struct twriter * tw,int base,const char * msg,int size)843 static int push_len(struct twriter *tw, int base, const char *msg, int size)
844 {
845 struct tw_len *lp;
846
847 if (tw->len_count >= LEN_STACK_SIZE) {
848 fprintf(stderr, "Length-stack overflow: %s\n", msg);
849 return -1;
850 }
851 if (size != 4 && size != 8) {
852 fprintf(stderr, "Length-stack invalid size %d: %s\n", size,
853 msg);
854 return -1;
855 }
856
857 lp = &tw->len_stack[tw->len_count++];
858 lp->base = base;
859 lp->ptr = tw->ptr;
860 lp->size = size;
861
862 return size == 8 ? tputq(tw->fout, 0) : tputl(tw->fout, 0);
863 }
864
865 /**
866 * pop_len() - Update a length value once the length is known
867 *
868 * Pops a value of the length stack and updates the file at that position with
869 * the number of bytes written between now and then. Once done, the file is
870 * seeked to the current (tw->ptr) position again, so writing can continue as
871 * normal.
872 *
873 * @tw: Writer context
874 * @msg: Indicates the type of caller, for debugging
875 * Returns 0 if OK, -1 on error
876 */
pop_len(struct twriter * tw,const char * msg)877 static int pop_len(struct twriter *tw, const char *msg)
878 {
879 struct tw_len *lp;
880 int len, ret;
881
882 if (!tw->len_count) {
883 fprintf(stderr, "Length-stack underflow: %s\n", msg);
884 return -1;
885 }
886
887 lp = &tw->len_stack[--tw->len_count];
888 if (fseek(tw->fout, lp->ptr, SEEK_SET))
889 return -1;
890 len = tw->ptr - lp->base;
891 ret = lp->size == 8 ? tputq(tw->fout, len) : tputl(tw->fout, len);
892 if (ret < 0)
893 return -1;
894 if (fseek(tw->fout, tw->ptr, SEEK_SET))
895 return -1;
896
897 return 0;
898 }
899
900 /**
901 * start_header() - Start a v7 section
902 *
903 * Writes a header in v7 format
904 *
905 * @tw: Writer context
906 * @id: ID of header to write (SECTION_...)
907 * @flags: Flags value to write
908 * @name: Name of section
909 * Returns: number of bytes written
910 */
start_header(struct twriter * tw,int id,uint flags,const char * name)911 static int start_header(struct twriter *tw, int id, uint flags,
912 const char *name)
913 {
914 int str_id;
915 int lptr;
916 int base;
917 int ret;
918
919 base = tw->ptr + 16;
920 lptr = 0;
921 lptr += tputh(tw->fout, id);
922 lptr += tputh(tw->fout, flags);
923 str_id = add_str(tw, name);
924 if (str_id < 0)
925 return -1;
926 lptr += tputl(tw->fout, str_id);
927
928 /* placeholder for size */
929 ret = push_len(tw, base, "v7 header", 8);
930 if (ret < 0)
931 return -1;
932 lptr += ret;
933
934 return lptr;
935 }
936
937 /**
938 * start_page() - Start a new page of output data
939 *
940 * The output is arranged in 4KB pages with a base timestamp at the start of
941 * each. This starts a new page, making sure it is aligned to 4KB in the output
942 * file.
943 *
944 * @tw: Writer context
945 * @timestamp: Base timestamp for the page
946 */
start_page(struct twriter * tw,ulong timestamp)947 static int start_page(struct twriter *tw, ulong timestamp)
948 {
949 int start;
950 int ret;
951
952 /* move to start of next page */
953 start = ALIGN(tw->ptr, TRACE_PAGE_SIZE);
954 ret = fseek(tw->fout, start, SEEK_SET);
955 if (ret < 0) {
956 fprintf(stderr, "Cannot seek to page start\n");
957 return -1;
958 }
959 tw->ptr = start;
960
961 /* page header */
962 tw->ptr += tputq(tw->fout, timestamp);
963 ret = push_len(tw, start + 16, "page", 8);
964 if (ret < 0)
965 return ret;
966 tw->ptr += ret;
967
968 return 0;
969 }
970
971 /**
972 * finish_page() - finish a page
973 *
974 * Sets the lengths correctly and moves to the start of the next page
975 *
976 * @tw: Writer context
977 * Returns: 0 on success, -1 on error
978 */
finish_page(struct twriter * tw)979 static int finish_page(struct twriter *tw)
980 {
981 int ret, end;
982
983 ret = pop_len(tw, "page");
984 if (ret < 0)
985 return ret;
986 end = ALIGN(tw->ptr, TRACE_PAGE_SIZE);
987
988 /*
989 * Write a byte so that the data actually makes to the file, in the case
990 * that we never write any more pages
991 */
992 if (tw->ptr != end) {
993 if (fseek(tw->fout, end - 1, SEEK_SET)) {
994 fprintf(stderr, "cannot seek to start of next page\n");
995 return -1;
996 }
997 fputc(0, tw->fout);
998 tw->ptr = end;
999 }
1000
1001 return 0;
1002 }
1003
1004 /**
1005 * output_headers() - Output v6 headers to the file
1006 *
1007 * Writes out the various formats so that trace-cmd and kernelshark can make
1008 * sense of the data
1009 *
1010 * This updates tw->ptr as it goes
1011 *
1012 * @tw: Writer context
1013 * Returns: 0 on success, -ve on error
1014 */
output_headers(struct twriter * tw)1015 static int output_headers(struct twriter *tw)
1016 {
1017 FILE *fout = tw->fout;
1018 char str[800];
1019 int len, ret;
1020
1021 tw->ptr += fprintf(fout, "%c%c%ctracing6%c%c%c", 0x17, 0x08, 0x44,
1022 0 /* terminator */, 0 /* little endian */,
1023 4 /* 32-bit long values */);
1024
1025 /* host-machine page size 4KB */
1026 tw->ptr += tputl(fout, 4 << 10);
1027
1028 tw->ptr += fprintf(fout, "header_page%c", 0);
1029
1030 snprintf(str, sizeof(str),
1031 "\tfield: u64 timestamp;\toffset:0;\tsize:8;\tsigned:0;\n"
1032 "\tfield: local_t commit;\toffset:8;\tsize:8;\tsigned:1;\n"
1033 "\tfield: int overwrite;\toffset:8;\tsize:1;\tsigned:1;\n"
1034 "\tfield: char data;\toffset:16;\tsize:4080;\tsigned:1;\n");
1035 len = strlen(str);
1036 tw->ptr += tputq(fout, len);
1037 tw->ptr += tputs(fout, str);
1038
1039 if (VERSION7) {
1040 /* no compression */
1041 tw->ptr += fprintf(fout, "none%cversion%c\n", 0, 0);
1042
1043 ret = start_header(tw, SECTION_OPTIONS, 0, "options");
1044 if (ret < 0) {
1045 fprintf(stderr, "Cannot start option header\n");
1046 return -1;
1047 }
1048 tw->ptr += ret;
1049 tw->ptr += tputh(fout, OPTION_DONE);
1050 tw->ptr += tputl(fout, 8);
1051 tw->ptr += tputl(fout, 0);
1052 ret = pop_len(tw, "t7 header");
1053 if (ret < 0) {
1054 fprintf(stderr, "Cannot finish option header\n");
1055 return -1;
1056 }
1057 }
1058
1059 tw->ptr += fprintf(fout, "header_event%c", 0);
1060 snprintf(str, sizeof(str),
1061 "# compressed entry header\n"
1062 "\ttype_len : 5 bits\n"
1063 "\ttime_delta : 27 bits\n"
1064 "\tarray : 32 bits\n"
1065 "\n"
1066 "\tpadding : type == 29\n"
1067 "\ttime_extend : type == 30\n"
1068 "\ttime_stamp : type == 31\n"
1069 "\tdata max type_len == 28\n");
1070 len = strlen(str);
1071 tw->ptr += tputq(fout, len);
1072 tw->ptr += tputs(fout, str);
1073
1074 /* number of ftrace-event-format files */
1075 tw->ptr += tputl(fout, 3);
1076
1077 snprintf(str, sizeof(str),
1078 "name: function\n"
1079 "ID: 1\n"
1080 "format:\n"
1081 "\tfield:unsigned short common_type;\toffset:0;\tsize:2;\tsigned:0;\n"
1082 "\tfield:unsigned char common_flags;\toffset:2;\tsize:1;\tsigned:0;\n"
1083 "\tfield:unsigned char common_preempt_count;\toffset:3;\tsize:1;signed:0;\n"
1084 "\tfield:int common_pid;\toffset:4;\tsize:4;\tsigned:1;\n"
1085 "\n"
1086 "\tfield:unsigned long ip;\toffset:8;\tsize:8;\tsigned:0;\n"
1087 "\tfield:unsigned long parent_ip;\toffset:16;\tsize:8;\tsigned:0;\n"
1088 "\n"
1089 "print fmt: \" %%ps <-- %%ps\", (void *)REC->ip, (void *)REC->parent_ip\n");
1090 len = strlen(str);
1091 tw->ptr += tputq(fout, len);
1092 tw->ptr += tputs(fout, str);
1093
1094 snprintf(str, sizeof(str),
1095 "name: funcgraph_entry\n"
1096 "ID: 11\n"
1097 "format:\n"
1098 "\tfield:unsigned short common_type;\toffset:0;\tsize:2;\tsigned:0;\n"
1099 "\tfield:unsigned char common_flags;\toffset:2;\tsize:1;\tsigned:0;\n"
1100 "\tfield:unsigned char common_preempt_count;\toffset:3;\tsize:1;signed:0;\n"
1101 "\tfield:int common_pid;\toffset:4;\tsize:4;\tsigned:1;\n"
1102 "\n"
1103 "\tfield:unsigned long func;\toffset:8;\tsize:8;\tsigned:0;\n"
1104 "\tfield:int depth;\toffset:16;\tsize:4;\tsigned:1;\n"
1105 "\n"
1106 "print fmt: \"--> %%ps (%%d)\", (void *)REC->func, REC->depth\n");
1107 len = strlen(str);
1108 tw->ptr += tputq(fout, len);
1109 tw->ptr += tputs(fout, str);
1110
1111 snprintf(str, sizeof(str),
1112 "name: funcgraph_exit\n"
1113 "ID: 10\n"
1114 "format:\n"
1115 "\tfield:unsigned short common_type;\toffset:0;\tsize:2;\tsigned:0;\n"
1116 "\tfield:unsigned char common_flags;\toffset:2;\tsize:1;\tsigned:0;\n"
1117 "\tfield:unsigned char common_preempt_count;\toffset:3;\tsize:1;signed:0;\n"
1118 "\tfield:int common_pid;\toffset:4;\tsize:4;\tsigned:1;\n"
1119 "\n"
1120 "\tfield:unsigned long func;\toffset:8;\tsize:8;\tsigned:0;\n"
1121 "\tfield:int depth;\toffset:16;\tsize:4;\tsigned:1;\n"
1122 "\tfield:unsigned int overrun;\toffset:20;\tsize:4;\tsigned:0;\n"
1123 "\tfield:unsigned long long calltime;\toffset:24;\tsize:8;\tsigned:0;\n"
1124 "\tfield:unsigned long long rettime;\toffset:32;\tsize:8;\tsigned:0;\n"
1125 "\n"
1126 "print fmt: \"<-- %%ps (%%d) (start: %%llx end: %%llx) over: %%d\", (void *)REC->func, REC->depth, REC->calltime, REC->rettime, REC->depth\n");
1127 len = strlen(str);
1128 tw->ptr += tputq(fout, len);
1129 tw->ptr += tputs(fout, str);
1130
1131 return 0;
1132 }
1133
1134 /**
1135 * write_symbols() - Write the symbols out
1136 *
1137 * Writes the symbol information in the following format to mimic the Linux
1138 * /proc/kallsyms file:
1139 *
1140 * <address> T <name>
1141 *
1142 * This updates tw->ptr as it goes
1143 *
1144 * @tw: Writer context
1145 * Returns: 0 on success, -ve on error
1146 */
write_symbols(struct twriter * tw)1147 static int write_symbols(struct twriter *tw)
1148 {
1149 char str[200];
1150 int ret, i;
1151
1152 /* write symbols */
1153 ret = push_len(tw, tw->ptr + 4, "syms", 4);
1154 if (ret < 0)
1155 return -1;
1156 tw->ptr += ret;
1157 for (i = 0; i < func_count; i++) {
1158 struct func_info *func = &func_list[i];
1159
1160 snprintf(str, sizeof(str), "%016lx T %s\n",
1161 text_offset + func->offset, func->name);
1162 tw->ptr += tputs(tw->fout, str);
1163 }
1164 ret = pop_len(tw, "syms");
1165 if (ret < 0)
1166 return -1;
1167 tw->ptr += ret;
1168
1169 return 0;
1170 }
1171
1172 /**
1173 * write_options() - Write the options out
1174 *
1175 * Writes various options which are needed or useful. We use OPTION_TSC2NSEC
1176 * to indicates that values in the output need to be multiplied by 1000 since
1177 * U-Boot's trace values are in microseconds.
1178 *
1179 * This updates tw->ptr as it goes
1180 *
1181 * @tw: Writer context
1182 * Returns: 0 on success, -ve on error
1183 */
write_options(struct twriter * tw)1184 static int write_options(struct twriter *tw)
1185 {
1186 FILE *fout = tw->fout;
1187 char str[200];
1188 int len;
1189
1190 /* trace_printk, 0 for now */
1191 tw->ptr += tputl(fout, 0);
1192
1193 /* processes */
1194 snprintf(str, sizeof(str), "%d u-boot\n", TRACE_PID);
1195 len = strlen(str);
1196 tw->ptr += tputq(fout, len);
1197 tw->ptr += tputs(fout, str);
1198
1199 /* number of CPUs */
1200 tw->ptr += tputl(fout, 1);
1201
1202 tw->ptr += fprintf(fout, "options %c", 0);
1203
1204 /* traceclock */
1205 tw->ptr += tputh(fout, OPTION_TRACECLOCK);
1206 tw->ptr += tputl(fout, 0);
1207
1208 /* uname */
1209 tw->ptr += tputh(fout, OPTION_UNAME);
1210 snprintf(str, sizeof(str), "U-Boot");
1211 len = strlen(str);
1212 tw->ptr += tputl(fout, len);
1213 tw->ptr += tputs(fout, str);
1214
1215 /* version */
1216 tw->ptr += tputh(fout, OPTION_VERSION);
1217 snprintf(str, sizeof(str), "unknown");
1218 len = strlen(str);
1219 tw->ptr += tputl(fout, len);
1220 tw->ptr += tputs(fout, str);
1221
1222 /* trace ID */
1223 tw->ptr += tputh(fout, OPTION_TRACEID);
1224 tw->ptr += tputl(fout, 8);
1225 tw->ptr += tputq(fout, 0x123456780abcdef0);
1226
1227 /* time conversion */
1228 tw->ptr += tputh(fout, OPTION_TSC2NSEC);
1229 tw->ptr += tputl(fout, 16);
1230 tw->ptr += tputl(fout, 1000); /* multiplier */
1231 tw->ptr += tputl(fout, 0); /* shift */
1232 tw->ptr += tputq(fout, 0); /* offset */
1233
1234 /* cpustat - bogus data for now, but at least it mentions the CPU */
1235 tw->ptr += tputh(fout, OPTION_CPUSTAT);
1236 snprintf(str, sizeof(str),
1237 "CPU: 0\n"
1238 "entries: 100\n"
1239 "overrun: 43565\n"
1240 "commit overrun: 0\n"
1241 "bytes: 3360\n"
1242 "oldest event ts: 963732.447752\n"
1243 "now ts: 963832.146824\n"
1244 "dropped events: 0\n"
1245 "read events: 42379\n");
1246 len = strlen(str);
1247 tw->ptr += tputl(fout, len);
1248 tw->ptr += tputs(fout, str);
1249
1250 tw->ptr += tputh(fout, OPTION_DONE);
1251
1252 return 0;
1253 }
1254
1255 /**
1256 * calc_min_depth() - Calculate the minimum call depth from the call list
1257 *
1258 * Starting with a depth of 0, this works through the call list, adding 1 for
1259 * each function call and subtracting 1 for each function return. Most likely
1260 * the value ends up being negative, since the trace does not start at the
1261 * very top of the call stack, e.g. main(), but some function called by that.
1262 *
1263 * This value can be used to calculate the depth value for the first call,
1264 * such that it never goes negative for subsequent returns.
1265 *
1266 * Returns: minimum call depth (e.g. -2)
1267 */
calc_min_depth(void)1268 static int calc_min_depth(void)
1269 {
1270 struct trace_call *call;
1271 int depth, min_depth, i;
1272
1273 /* Calculate minimum depth */
1274 depth = 0;
1275 min_depth = 0;
1276 for (i = 0, call = call_list; i < call_count; i++, call++) {
1277 switch (TRACE_CALL_TYPE(call)) {
1278 case FUNCF_ENTRY:
1279 depth++;
1280 break;
1281 case FUNCF_EXIT:
1282 depth--;
1283 if (depth < min_depth)
1284 min_depth = depth;
1285 break;
1286 }
1287 }
1288
1289 return min_depth;
1290 }
1291
1292 /**
1293 * write_pages() - Write the pages of trace data
1294 *
1295 * This works through all the calls, writing out as many pages of data as are
1296 * needed.
1297 *
1298 * @tw: Writer context
1299 * @out_format: Output format to use
1300 * @missing_countp: Returns number of missing functions (not found in function
1301 * list)
1302 * @skip_countp: Returns number of skipped functions (excluded from trace)
1303 *
1304 * Returns: 0 on success, -ve on error
1305 */
write_pages(struct twriter * tw,enum out_format_t out_format,int * missing_countp,int * skip_countp)1306 static int write_pages(struct twriter *tw, enum out_format_t out_format,
1307 int *missing_countp, int *skip_countp)
1308 {
1309 ulong func_stack[MAX_STACK_DEPTH];
1310 int stack_ptr; /* next free position in stack */
1311 int upto, depth, page_upto, i;
1312 int missing_count = 0, skip_count = 0;
1313 struct trace_call *call;
1314 ulong last_timestamp;
1315 FILE *fout = tw->fout;
1316 int last_delta = 0;
1317 int err_count;
1318 bool in_page;
1319
1320 in_page = false;
1321 last_timestamp = 0;
1322 upto = 0;
1323 page_upto = 0;
1324 err_count = 0;
1325
1326 /* maintain a stack of start times for calling functions */
1327 stack_ptr = 0;
1328
1329 /*
1330 * The first thing in the trace may not be the top-level function, so
1331 * set the initial depth so that no function goes below depth 0
1332 */
1333 depth = -calc_min_depth();
1334 for (i = 0, call = call_list; i < call_count; i++, call++) {
1335 bool entry = TRACE_CALL_TYPE(call) == FUNCF_ENTRY;
1336 struct func_info *func;
1337 ulong timestamp;
1338 uint rec_words;
1339 int delta;
1340
1341 func = find_func_by_offset(call->func);
1342 if (!func) {
1343 warn("Cannot find function at %lx\n",
1344 text_offset + call->func);
1345 missing_count++;
1346 if (missing_count > 20) {
1347 /* perhaps trace does not match System.map */
1348 fprintf(stderr, "Too many missing functions\n");
1349 return -1;
1350 }
1351 continue;
1352 }
1353
1354 if (!(func->flags & FUNCF_TRACE)) {
1355 debug("Funcion '%s' is excluded from trace\n",
1356 func->name);
1357 skip_count++;
1358 continue;
1359 }
1360
1361 if (out_format == OUT_FMT_FUNCTION)
1362 rec_words = 6;
1363 else /* 2 header words and then 3 or 8 others */
1364 rec_words = 2 + (entry ? 3 : 8);
1365
1366 /* convert timestamp from us to ns */
1367 timestamp = call->flags & FUNCF_TIMESTAMP_MASK;
1368 if (in_page) {
1369 if (page_upto + rec_words * 4 > TRACE_PAGE_SIZE) {
1370 if (finish_page(tw))
1371 return -1;
1372 in_page = false;
1373 }
1374 }
1375 if (!in_page) {
1376 if (start_page(tw, timestamp))
1377 return -1;
1378 in_page = true;
1379 last_timestamp = timestamp;
1380 last_delta = 0;
1381 page_upto = tw->ptr & TRACE_PAGE_MASK;
1382 if (_DEBUG) {
1383 fprintf(stderr,
1384 "new page, last_timestamp=%ld, upto=%d\n",
1385 last_timestamp, upto);
1386 }
1387 }
1388
1389 delta = timestamp - last_timestamp;
1390 if (delta < 0) {
1391 fprintf(stderr, "Time went backwards\n");
1392 err_count++;
1393 }
1394
1395 if (err_count > 20) {
1396 fprintf(stderr, "Too many errors, giving up\n");
1397 return -1;
1398 }
1399
1400 if (delta > 0x07fffff) {
1401 /*
1402 * hard to imagine how this could happen since it means
1403 * that no function calls were made for a long time
1404 */
1405 fprintf(stderr, "cannot represent time delta %x\n",
1406 delta);
1407 return -1;
1408 }
1409
1410 if (out_format == OUT_FMT_FUNCTION) {
1411 struct func_info *caller_func;
1412
1413 if (_DEBUG) {
1414 fprintf(stderr, "%d: delta=%d, stamp=%ld\n",
1415 upto, delta, timestamp);
1416 fprintf(stderr,
1417 " last_delta %x to %x: last_timestamp=%lx, "
1418 "timestamp=%lx, call->flags=%x, upto=%d\n",
1419 last_delta, delta, last_timestamp,
1420 timestamp, call->flags, upto);
1421 }
1422
1423 /* type_len is 6, meaning 4 * 6 = 24 bytes */
1424 tw->ptr += tputl(fout, rec_words | (uint)delta << 5);
1425 tw->ptr += tputh(fout, TRACE_FN);
1426 tw->ptr += tputh(fout, 0); /* flags */
1427 tw->ptr += tputl(fout, TRACE_PID); /* PID */
1428 /* function */
1429 tw->ptr += tputq(fout, text_offset + func->offset);
1430 caller_func = find_caller_by_offset(call->caller);
1431 /* caller */
1432 tw->ptr += tputq(fout,
1433 text_offset + caller_func->offset);
1434 } else {
1435 tw->ptr += tputl(fout, rec_words | delta << 5);
1436 tw->ptr += tputh(fout, entry ? TRACE_GRAPH_ENT
1437 : TRACE_GRAPH_RET);
1438 tw->ptr += tputh(fout, 0); /* flags */
1439 tw->ptr += tputl(fout, TRACE_PID); /* PID */
1440 /* function */
1441 tw->ptr += tputq(fout, text_offset + func->offset);
1442 tw->ptr += tputl(fout, depth); /* depth */
1443 if (entry) {
1444 depth++;
1445 if (stack_ptr < MAX_STACK_DEPTH)
1446 func_stack[stack_ptr] = timestamp;
1447 stack_ptr++;
1448 } else {
1449 ulong func_duration = 0;
1450
1451 depth--;
1452 if (stack_ptr && stack_ptr <= MAX_STACK_DEPTH) {
1453 ulong start = func_stack[--stack_ptr];
1454
1455 func_duration = timestamp - start;
1456 }
1457 tw->ptr += tputl(fout, 0); /* overrun */
1458 tw->ptr += tputq(fout, 0); /* calltime */
1459 /* rettime */
1460 tw->ptr += tputq(fout, func_duration);
1461 }
1462 }
1463
1464 last_delta = delta;
1465 last_timestamp = timestamp;
1466 page_upto += 4 + rec_words * 4;
1467 upto++;
1468 if (stack_ptr == MAX_STACK_DEPTH)
1469 break;
1470 }
1471 if (in_page && finish_page(tw))
1472 return -1;
1473 *missing_countp = missing_count;
1474 *skip_countp = skip_count;
1475
1476 return 0;
1477 }
1478
1479 /**
1480 * write_flyrecord() - Write the flyrecord information
1481 *
1482 * Writes the header and pages of data for the "flyrecord" section. It also
1483 * writes out the counter-type info, selecting "[local]"
1484 *
1485 * @tw: Writer context
1486 * @out_format: Output format to use
1487 * @missing_countp: Returns number of missing functions (not found in function
1488 * list)
1489 * @skip_countp: Returns number of skipped functions (excluded from trace)
1490 *
1491 * Returns: 0 on success, -ve on error
1492 */
write_flyrecord(struct twriter * tw,enum out_format_t out_format,int * missing_countp,int * skip_countp)1493 static int write_flyrecord(struct twriter *tw, enum out_format_t out_format,
1494 int *missing_countp, int *skip_countp)
1495 {
1496 int start, ret, len;
1497 FILE *fout = tw->fout;
1498 char str[200];
1499
1500 tw->ptr += fprintf(fout, "flyrecord%c", 0);
1501
1502 /* trace data */
1503 start = ALIGN(tw->ptr + 16, TRACE_PAGE_SIZE);
1504 tw->ptr += tputq(fout, start);
1505
1506 /* use a placeholder for the size */
1507 ret = push_len(tw, start, "flyrecord", 8);
1508 if (ret < 0)
1509 return -1;
1510 tw->ptr += ret;
1511
1512 snprintf(str, sizeof(str),
1513 "[local] global counter uptime perf mono mono_raw boot x86-tsc\n");
1514 len = strlen(str);
1515 tw->ptr += tputq(fout, len);
1516 tw->ptr += tputs(fout, str);
1517
1518 debug("trace text base %lx, map file %lx\n", text_base, text_offset);
1519
1520 ret = write_pages(tw, out_format, missing_countp, skip_countp);
1521 if (ret < 0) {
1522 fprintf(stderr, "Cannot output pages\n");
1523 return -1;
1524 }
1525
1526 ret = pop_len(tw, "flyrecord");
1527 if (ret < 0) {
1528 fprintf(stderr, "Cannot finish flyrecord header\n");
1529 return -1;
1530 }
1531
1532 return 0;
1533 }
1534
1535 /**
1536 * make_ftrace() - Write out an ftrace file
1537 *
1538 * See here for format:
1539 *
1540 * https://github.com/rostedt/trace-cmd/blob/master/Documentation/trace-cmd/trace-cmd.dat.v7.5.txt
1541 *
1542 * @fout: Output file
1543 * @out_format: Output format to use
1544 * Returns: 0 on success, -ve on error
1545 */
make_ftrace(FILE * fout,enum out_format_t out_format)1546 static int make_ftrace(FILE *fout, enum out_format_t out_format)
1547 {
1548 int missing_count, skip_count;
1549 struct twriter tws, *tw = &tws;
1550 int ret;
1551
1552 memset(tw, '\0', sizeof(*tw));
1553 abuf_init(&tw->str_buf);
1554 tw->fout = fout;
1555
1556 tw->ptr = 0;
1557 ret = output_headers(tw);
1558 if (ret < 0) {
1559 fprintf(stderr, "Cannot output headers\n");
1560 return -1;
1561 }
1562 /* number of event systems files */
1563 tw->ptr += tputl(fout, 0);
1564
1565 ret = write_symbols(tw);
1566 if (ret < 0) {
1567 fprintf(stderr, "Cannot write symbols\n");
1568 return -1;
1569 }
1570
1571 ret = write_options(tw);
1572 if (ret < 0) {
1573 fprintf(stderr, "Cannot write options\n");
1574 return -1;
1575 }
1576
1577 ret = write_flyrecord(tw, out_format, &missing_count, &skip_count);
1578 if (ret < 0) {
1579 fprintf(stderr, "Cannot write flyrecord\n");
1580 return -1;
1581 }
1582
1583 info("ftrace: %d functions not found, %d excluded\n", missing_count,
1584 skip_count);
1585
1586 return 0;
1587 }
1588
1589 /**
1590 * create_node() - Create a new node in the flamegraph tree
1591 *
1592 * @msg: Message to use for debugging if something goes wrong
1593 * Returns: Pointer to newly created node, or NULL on error
1594 */
create_node(const char * msg)1595 static struct flame_node *create_node(const char *msg)
1596 {
1597 struct flame_node *node;
1598
1599 node = calloc(1, sizeof(*node));
1600 if (!node) {
1601 fprintf(stderr, "Out of memory for %s\n", msg);
1602 return NULL;
1603 }
1604 INIT_LIST_HEAD(&node->child_head);
1605
1606 return node;
1607 }
1608
1609 /**
1610 * process_call(): Add a call to the flamegraph info
1611 *
1612 * For function calls, if this call stack has been seen before, this increments
1613 * the call count, creating a new node if needed.
1614 *
1615 * For function returns, it adds up the time spent in this call stack,
1616 * subtracting the time spent by child functions.
1617 *
1618 * @state: Current flamegraph state
1619 * @entry: true if this is a function entry, false if a function exit
1620 * @timestamp: Timestamp from the trace file (in microseconds)
1621 * @func: Function that was called/returned from
1622 *
1623 * Returns: 0 on success, -ve on error
1624 */
process_call(struct flame_state * state,bool entry,ulong timestamp,struct func_info * func)1625 static int process_call(struct flame_state *state, bool entry, ulong timestamp,
1626 struct func_info *func)
1627 {
1628 struct flame_node *node = state->node;
1629 int stack_ptr = state->stack_ptr;
1630
1631 if (entry) {
1632 struct flame_node *child, *chd;
1633
1634 /* see if we have this as a child node already */
1635 child = NULL;
1636 list_for_each_entry(chd, &node->child_head, sibling_node) {
1637 if (chd->func == func) {
1638 child = chd;
1639 break;
1640 }
1641 }
1642 if (!child) {
1643 /* create a new node */
1644 child = create_node("child");
1645 if (!child)
1646 return -1;
1647 list_add_tail(&child->sibling_node, &node->child_head);
1648 child->func = func;
1649 child->parent = node;
1650 state->nodes++;
1651 }
1652 debug("entry %s: move from %s to %s\n", func->name,
1653 node->func ? node->func->name : "(root)",
1654 child->func->name);
1655 child->count++;
1656 if (stack_ptr < MAX_STACK_DEPTH) {
1657 state->stack[stack_ptr].timestamp = timestamp;
1658 state->stack[stack_ptr].child_total = 0;
1659 }
1660 debug("%d: %20s: entry at %ld\n", stack_ptr, func->name,
1661 timestamp);
1662 stack_ptr++;
1663 node = child;
1664 } else if (node->parent) {
1665 ulong total_duration = 0, child_duration = 0;
1666 struct stack_info *stk;
1667
1668 debug("exit %s: move from %s to %s\n", func->name,
1669 node->func->name, node->parent->func ?
1670 node->parent->func->name : "(root)");
1671 if (stack_ptr && stack_ptr <= MAX_STACK_DEPTH) {
1672 stk = &state->stack[--stack_ptr];
1673
1674 /*
1675 * get total duration of the function which just
1676 * exited
1677 */
1678 total_duration = timestamp - stk->timestamp;
1679 child_duration = stk->child_total;
1680
1681 if (stack_ptr)
1682 state->stack[stack_ptr - 1].child_total += total_duration;
1683
1684 debug("%d: %20s: exit at %ld, total %ld, child %ld, child_total=%ld\n",
1685 stack_ptr, func->name, timestamp,
1686 total_duration, child_duration,
1687 stk->child_total);
1688 }
1689 node->duration += total_duration - child_duration;
1690 node = node->parent;
1691 }
1692
1693 state->stack_ptr = stack_ptr;
1694 state->node = node;
1695
1696 return 0;
1697 }
1698
1699 /**
1700 * make_flame_tree() - Create a tree of stack traces
1701 *
1702 * Set up a tree, with the root node having the top-level functions as children
1703 * and the leaf nodes being leaf functions. Each node has a count of how many
1704 * times this function appears in the trace
1705 *
1706 * @out_format: Output format to use
1707 * @treep: Returns the resulting flamegraph tree
1708 * Returns: 0 on success, -ve on error
1709 */
make_flame_tree(enum out_format_t out_format,struct flame_node ** treep)1710 static int make_flame_tree(enum out_format_t out_format,
1711 struct flame_node **treep)
1712 {
1713 struct flame_state state;
1714 struct flame_node *tree;
1715 struct trace_call *call;
1716 int i;
1717
1718 /* maintain a stack of start times, etc. for 'calling' functions */
1719 state.stack_ptr = 0;
1720
1721 tree = create_node("tree");
1722 if (!tree)
1723 return -1;
1724 state.node = tree;
1725 state.nodes = 0;
1726
1727 for (i = 0, call = call_list; i < call_count; i++, call++) {
1728 bool entry = TRACE_CALL_TYPE(call) == FUNCF_ENTRY;
1729 ulong timestamp = call->flags & FUNCF_TIMESTAMP_MASK;
1730 struct func_info *func;
1731
1732 func = find_func_by_offset(call->func);
1733 if (!func) {
1734 warn("Cannot find function at %lx\n",
1735 text_offset + call->func);
1736 continue;
1737 }
1738
1739 if (process_call(&state, entry, timestamp, func))
1740 return -1;
1741 }
1742 fprintf(stderr, "%d nodes\n", state.nodes);
1743 *treep = tree;
1744
1745 return 0;
1746 }
1747
1748 /**
1749 * output_tree() - Output a flamegraph tree
1750 *
1751 * Writes the tree out to a file in a format suitable for flamegraph.pl
1752 *
1753 * This works by maintaining a string shared across all recursive calls. The
1754 * function name for this node is added to the existing string, to make up the
1755 * full call-stack description. For example, on entry, @str might contain:
1756 *
1757 * "initf_bootstage;bootstage_mark_name"
1758 * ^ @base
1759 *
1760 * with @base pointing to the \0 at the end of the string. This function adds
1761 * a ';' following by the name of the current function, e.g. "timer_get_boot_us"
1762 * as well as the output value, to get the full line:
1763 *
1764 * initf_bootstage;bootstage_mark_name;timer_get_boot_us 123
1765 *
1766 * @fout: Output file
1767 * @out_format: Output format to use
1768 * @node: Node to output (pass the whole tree at first)
1769 * @str: String to use to build the output line (e.g. 500 charas long)
1770 * @maxlen: Maximum length of string
1771 * @base: Current base position in the string
1772 * @treep: Returns the resulting flamegraph tree
1773 * Returns 0 if OK, -1 on error
1774 */
output_tree(FILE * fout,enum out_format_t out_format,const struct flame_node * node,char * str,int maxlen,int base)1775 static int output_tree(FILE *fout, enum out_format_t out_format,
1776 const struct flame_node *node, char *str, int maxlen,
1777 int base)
1778 {
1779 const struct flame_node *child;
1780 int pos;
1781
1782 if (node->count) {
1783 if (out_format == OUT_FMT_FLAMEGRAPH_CALLS) {
1784 fprintf(fout, "%s %d\n", str, node->count);
1785 } else {
1786 /*
1787 * Write out the number of microseconds used by this
1788 * call stack. Since the time taken by child calls is
1789 * subtracted from this total, it can reach 0, meaning
1790 * that this function took no time beyond what its
1791 * children used. For this case, write 1 rather than 0,
1792 * so that this call stack appears in the flamegraph.
1793 * This has the effect of inflating the timing slightly,
1794 * but only by at most 1 microsecond per function,
1795 * assuming that is the timestamp resolution
1796 */
1797 fprintf(fout, "%s %ld\n", str,
1798 node->duration ? node->duration : 1);
1799 }
1800 }
1801
1802 pos = base;
1803 if (pos)
1804 str[pos++] = ';';
1805 list_for_each_entry(child, &node->child_head, sibling_node) {
1806 int len;
1807
1808 len = strlen(child->func->name);
1809 if (pos + len + 1 >= maxlen) {
1810 fprintf(stderr, "String too short (%d chars)\n",
1811 maxlen);
1812 return -1;
1813 }
1814 strcpy(str + pos, child->func->name);
1815 if (output_tree(fout, out_format, child, str, maxlen,
1816 pos + len))
1817 return -1;
1818 }
1819
1820 return 0;
1821 }
1822
1823 /**
1824 * make_flamegraph() - Write out a flame graph
1825 *
1826 * @fout: Output file
1827 * @out_format: Output format to use, e.g. function counts or timing
1828 * Returns 0 if OK, -1 on error
1829 */
make_flamegraph(FILE * fout,enum out_format_t out_format)1830 static int make_flamegraph(FILE *fout, enum out_format_t out_format)
1831 {
1832 struct flame_node *tree;
1833 char str[500];
1834
1835 if (make_flame_tree(out_format, &tree))
1836 return -1;
1837
1838 *str = '\0';
1839 if (output_tree(fout, out_format, tree, str, sizeof(str), 0))
1840 return -1;
1841
1842 return 0;
1843 }
1844
1845 /**
1846 * prof_tool() - Performs requested action
1847 *
1848 * @argc: Number of arguments (used to obtain the command
1849 * @argv: List of arguments
1850 * @trace_fname: Filename of input file (trace data from U-Boot)
1851 * @map_fname: Filename of map file (System.map from U-Boot)
1852 * @trace_config_fname: Trace-configuration file, or NULL if none
1853 * @out_fname: Output filename
1854 */
prof_tool(int argc,char * const argv[],const char * trace_fname,const char * map_fname,const char * trace_config_fname,const char * out_fname,enum out_format_t out_format)1855 static int prof_tool(int argc, char *const argv[],
1856 const char *trace_fname, const char *map_fname,
1857 const char *trace_config_fname, const char *out_fname,
1858 enum out_format_t out_format)
1859 {
1860 int err = 0;
1861
1862 if (read_map_file(map_fname))
1863 return -1;
1864 if (trace_fname && read_trace_file(trace_fname))
1865 return -1;
1866 if (trace_config_fname && read_trace_config_file(trace_config_fname))
1867 return -1;
1868
1869 check_trace_config();
1870
1871 for (; argc; argc--, argv++) {
1872 const char *cmd = *argv;
1873
1874 if (!strcmp(cmd, "dump-ftrace")) {
1875 FILE *fout;
1876
1877 if (out_format != OUT_FMT_FUNCTION &&
1878 out_format != OUT_FMT_FUNCGRAPH)
1879 out_format = OUT_FMT_FUNCTION;
1880 fout = fopen(out_fname, "w");
1881 if (!fout) {
1882 fprintf(stderr, "Cannot write file '%s'\n",
1883 out_fname);
1884 return -1;
1885 }
1886 err = make_ftrace(fout, out_format);
1887 fclose(fout);
1888 } else if (!strcmp(cmd, "dump-flamegraph")) {
1889 FILE *fout;
1890
1891 if (out_format != OUT_FMT_FLAMEGRAPH_CALLS &&
1892 out_format != OUT_FMT_FLAMEGRAPH_TIMING)
1893 out_format = OUT_FMT_FLAMEGRAPH_CALLS;
1894 fout = fopen(out_fname, "w");
1895 if (!fout) {
1896 fprintf(stderr, "Cannot write file '%s'\n",
1897 out_fname);
1898 return -1;
1899 }
1900 err = make_flamegraph(fout, out_format);
1901 fclose(fout);
1902 } else {
1903 warn("Unknown command '%s'\n", cmd);
1904 }
1905 }
1906
1907 return err;
1908 }
1909
main(int argc,char * argv[])1910 int main(int argc, char *argv[])
1911 {
1912 enum out_format_t out_format = OUT_FMT_DEFAULT;
1913 const char *map_fname = "System.map";
1914 const char *trace_fname = NULL;
1915 const char *config_fname = NULL;
1916 const char *out_fname = NULL;
1917 int opt;
1918
1919 verbose = 2;
1920 while ((opt = getopt(argc, argv, "c:f:m:o:t:v:")) != -1) {
1921 switch (opt) {
1922 case 'c':
1923 config_fname = optarg;
1924 break;
1925 case 'f':
1926 if (!strcmp("function", optarg)) {
1927 out_format = OUT_FMT_FUNCTION;
1928 } else if (!strcmp("funcgraph", optarg)) {
1929 out_format = OUT_FMT_FUNCGRAPH;
1930 } else if (!strcmp("calls", optarg)) {
1931 out_format = OUT_FMT_FLAMEGRAPH_CALLS;
1932 } else if (!strcmp("timing", optarg)) {
1933 out_format = OUT_FMT_FLAMEGRAPH_TIMING;
1934 } else {
1935 fprintf(stderr,
1936 "Invalid format: use function, funcgraph, calls, timing\n");
1937 exit(1);
1938 }
1939 break;
1940 case 'm':
1941 map_fname = optarg;
1942 break;
1943 case 'o':
1944 out_fname = optarg;
1945 break;
1946 case 't':
1947 trace_fname = optarg;
1948 break;
1949 case 'v':
1950 verbose = atoi(optarg);
1951 break;
1952 default:
1953 usage();
1954 }
1955 }
1956 argc -= optind; argv += optind;
1957 if (argc < 1)
1958 usage();
1959
1960 if (!out_fname || !map_fname || !trace_fname) {
1961 fprintf(stderr,
1962 "Must provide trace data, System.map file and output file\n");
1963 usage();
1964 }
1965
1966 debug("Debug enabled\n");
1967 return prof_tool(argc, argv, trace_fname, map_fname, config_fname,
1968 out_fname, out_format);
1969 }
1970