riscv: qemu: imply GOLDFISH_RTC

[thirdparty/u-boot.git] / tools / proftool.c

// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright 2023 Google LLC
 * Written by Simon Glass <sjg@chromium.org>
 */

/*
 * Decode and dump U-Boot trace information into formats that can be used
 * by trace-cmd, kernelshark or flamegraph.pl
 *
 * See doc/develop/trace.rst for more information
 */

#include <assert.h>
#include <ctype.h>
#include <limits.h>
#include <regex.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/param.h>
#include <sys/types.h>

#include <compiler.h>
#include <trace.h>
#include <abuf.h>

#include <linux/list.h>

/* Set to 1 to emit version 7 file (currently this doesn't work) */
#define VERSION7        0

/* enable some debug features */
#define _DEBUG  0

/* from linux/kernel.h */
#define __ALIGN_MASK(x, mask)   (((x) + (mask)) & ~(mask))
#define ALIGN(x, a)             __ALIGN_MASK((x), (typeof(x))(a) - 1)

/**
 * container_of - cast a member of a structure out to the containing structure
 * @ptr:        the pointer to the member.
 * @type:       the type of the container struct this is embedded in.
 * @member:     the name of the member within the struct.
 *
 * (this is needed by list.h)
 */
#define container_of(ptr, type, member) ({                      \
        const typeof( ((type *)0)->member ) *__mptr = (ptr);    \
        (type *)( (char *)__mptr - offsetof(type,member) );})

enum {
        FUNCF_TRACE     = 1 << 0,       /* Include this function in trace */
        TRACE_PAGE_SIZE = 4096,         /* Assumed page size for trace */
        TRACE_PID       = 1,            /* PID to use for U-Boot */
        LEN_STACK_SIZE  = 4,            /* number of nested length fix-ups */
        TRACE_PAGE_MASK = TRACE_PAGE_SIZE - 1,
        MAX_STACK_DEPTH = 50,           /* Max nested function calls */
        MAX_LINE_LEN    = 500,          /* Max characters per line */
};

/**
 * enum out_format_t - supported output formats
 *
 * @OUT_FMT_DEFAULT: Use the default for the output file
 * @OUT_FMT_FUNCTION: Write ftrace 'function' records
 * @OUT_FMT_FUNCGRAPH: Write ftrace funcgraph_entry and funcgraph_exit records
 * @OUT_FMT_FLAMEGRAPH_CALLS: Write a file suitable for flamegraph.pl
 * @OUT_FMT_FLAMEGRAPH_TIMING: Write a file suitable for flamegraph.pl with the
 * counts set to the number of microseconds used by each function
 */
enum out_format_t {
        OUT_FMT_DEFAULT,
        OUT_FMT_FUNCTION,
        OUT_FMT_FUNCGRAPH,
        OUT_FMT_FLAMEGRAPH_CALLS,
        OUT_FMT_FLAMEGRAPH_TIMING,
};

/* Section types for v7 format (trace-cmd format) */
enum {
        SECTION_OPTIONS,
};

/* Option types (trace-cmd format) */
enum {
        OPTION_DONE,
        OPTION_DATE,
        OPTION_CPUSTAT,
        OPTION_BUFFER,
        OPTION_TRACECLOCK,
        OPTION_UNAME,
        OPTION_HOOK,
        OPTION_OFFSET,
        OPTION_CPUCOUNT,
        OPTION_VERSION,
        OPTION_PROCMAPS,
        OPTION_TRACEID,
        OPTION_TIME_SHIFT,
        OPTION_GUEST,
        OPTION_TSC2NSEC,
};

/* types of trace records (trace-cmd format) */
enum trace_type {
        __TRACE_FIRST_TYPE = 0,

        TRACE_FN,
        TRACE_CTX,
        TRACE_WAKE,
        TRACE_STACK,
        TRACE_PRINT,
        TRACE_BPRINT,
        TRACE_MMIO_RW,
        TRACE_MMIO_MAP,
        TRACE_BRANCH,
        TRACE_GRAPH_RET,
        TRACE_GRAPH_ENT,
};

/**
 * struct flame_node - a node in the call-stack tree
 *
 * Each stack frame detected in the trace is given a node corresponding to a
 * function call in the call stack. Functions can appear multiple times when
 * they are called by a different set of parent functions.
 *
 * @parent: Parent node (the call stack for the function that called this one)
 * @child_head: List of children of this node (functions called from here)
 * @sibling: Next node in the list of children
 * @func: Function this node refers to (NULL for root node)
 * @count: Number of times this call-stack occurred
 * @duration: Number of microseconds taken to run this function, excluding all
 * of the functions it calls
 */
struct flame_node {
        struct flame_node *parent;
        struct list_head child_head;
        struct list_head sibling_node;
        struct func_info *func;
        int count;
        ulong duration;
};

/**
 * struct flame_state - state information for building the flame graph
 *
 * @node: Current node being processed (corresponds to a function call)
 * @stack: Stack of call-start time for this function as well as the
 * accumulated total time of all child calls (so we can subtract them from the
 * function's call time. This is an 'empty' stack, meaning that @stack_ptr
 * points to the next available stack position
 * @stack_ptr: points to first empty position in the stack
 * @nodes: Number of nodes created (running count)
 */
struct flame_state {
        struct flame_node *node;
        struct stack_info {
                ulong timestamp;
                ulong child_total;
        } stack[MAX_STACK_DEPTH];
        int stack_ptr;
        int nodes;
};

/**
 * struct func_info - information recorded for each function
 *
 * @offset: Function offset in the image, measured from the text_base
 * @name: Function name
 * @code_size: Total code size of the function
 * @flags: Either 0 or FUNCF_TRACE
 */
struct func_info {
        unsigned long offset;
        const char *name;
        unsigned long code_size;
        unsigned flags;
};

/**
 * enum trace_line_type - whether to include or exclude a function
 *
 * @TRACE_LINE_INCLUDE: Include the function
 * @TRACE_LINE_EXCLUDE: Exclude the function
 */
enum trace_line_type {
        TRACE_LINE_INCLUDE,
        TRACE_LINE_EXCLUDE,
};

/**
 * struct trace_configline_info - information about a config-file line
 *
 * @next: Next line
 * @type: Line type
 * @name: identifier name / wildcard
 * @regex: Regex to use if name starts with '/'
 */
struct trace_configline_info {
        struct trace_configline_info *next;
        enum trace_line_type type;
        const char *name;
        regex_t regex;
};

/**
 * struct tw_len - holds information about a length value that need fix-ups
 *
 * This is used to record a placeholder for a u32 or u64 length which is written
 * to the output file but needs to be updated once the length is actually known
 *
 * This allows us to write tw->ptr - @len_base to position @ptr in the file
 *
 * @ptr: Position of the length value in the file
 * @base: Base position for the calculation
 * @size: Size of the length value, in bytes (4 or 8)
 */
struct tw_len {
        int ptr;
        int base;
        int size;
};

/**
 * struct twriter - Writer for trace records
 *
 * Maintains state used when writing the output file in trace-cmd format
 *
 * @ptr: Current file position
 * @len_stack: Stack of length values that need fixing up
 * @len: Number of items on @len_stack
 * @str_buf: Buffer of strings (for v7 format)
 * @str_ptr: Current write-position in the buffer for strings
 * @fout: Output file
 */
struct twriter {
        int ptr;
        struct tw_len len_stack[LEN_STACK_SIZE];
        int len_count;
        struct abuf str_buf;
        int str_ptr;
        FILE *fout;
};

/* The contents of the trace config file */
struct trace_configline_info *trace_config_head;

/* list of all functions in System.map file, sorted by offset in the image */
struct func_info *func_list;

int func_count;                 /* number of functions */
struct trace_call *call_list;   /* list of all calls in the input trace file */
int call_count;                 /* number of calls */
int verbose;    /* Verbosity level 0=none, 1=warn, 2=notice, 3=info, 4=debug */
ulong text_offset;              /* text address of first function */
ulong text_base;                /* CONFIG_TEXT_BASE from trace file */

/* debugging helpers */
static void outf(int level, const char *fmt, ...)
                __attribute__ ((format (__printf__, 2, 3)));
#define error(fmt, b...) outf(0, fmt, ##b)
#define warn(fmt, b...) outf(1, fmt, ##b)
#define notice(fmt, b...) outf(2, fmt, ##b)
#define info(fmt, b...) outf(3, fmt, ##b)
#define debug(fmt, b...) outf(4, fmt, ##b)

static void outf(int level, const char *fmt, ...)
{
        if (verbose >= level) {
                va_list args;

                va_start(args, fmt);
                vfprintf(stderr, fmt, args);
                va_end(args);
        }
}

static void usage(void)
{
        fprintf(stderr,
                "Usage: proftool [-cmtv] <cmd> <profdata>\n"
                "\n"
                "Commands\n"
                "   dump-ftrace\t\tDump out records in ftrace format for use by trace-cmd\n"
                "   dump-flamegraph\tWrite a file for use with flamegraph.pl\n"
                "\n"
                "Options:\n"
                "   -c <cfg>\tSpecify config file\n"
                "   -f <subtype>\tSpecify output subtype\n"
                "   -m <map>\tSpecify Systen.map file\n"
                "   -o <fname>\tSpecify output file\n"
                "   -t <fname>\tSpecify trace data file (from U-Boot 'trace calls')\n"
                "   -v <0-4>\tSpecify verbosity\n"
                "\n"
                "Subtypes for dump-ftrace:\n"
                "   function - write function-call records (caller/callee)\n"
                "   funcgraph - write function entry/exit records (graph)\n"
                "\n"
                "Subtypes for dump-flamegraph\n"
                "   calls - create a flamegraph of stack frames\n"
                "   timing - create a flamegraph of microseconds for each stack frame\n");
        exit(EXIT_FAILURE);
}

/**
 * h_cmp_offset - bsearch() function to compare two functions bny their offset
 *
 * @v1: Pointer to first function (struct func_info)
 * @v2: Pointer to second function (struct func_info)
 * Returns: < 0 if v1 offset < v2 offset, 0 if equal, > 0 otherwise
 */
static int h_cmp_offset(const void *v1, const void *v2)
{
        const struct func_info *f1 = v1, *f2 = v2;

        return (f1->offset / FUNC_SITE_SIZE) - (f2->offset / FUNC_SITE_SIZE);
}

/**
 * read_system_map() - read the System.map file to create a list of functions
 *
 * This also reads the text_offset value, since we assume that the first text
 * symbol is at that address
 *
 * @fin: File to read
 * Returns: 0 if OK, non-zero on error
 */
static int read_system_map(FILE *fin)
{
        unsigned long offset, start = 0;
        struct func_info *func;
        char buff[MAX_LINE_LEN];
        char symtype;
        char symname[MAX_LINE_LEN + 1];
        int linenum;
        int alloced;

        for (linenum = 1, alloced = func_count = 0;; linenum++) {
                int fields = 0;

                if (fgets(buff, sizeof(buff), fin))
                        fields = sscanf(buff, "%lx %c %100s\n", &offset,
                                &symtype, symname);
                if (fields == 2) {
                        continue;
                } else if (feof(fin)) {
                        break;
                } else if (fields < 2) {
                        error("Map file line %d: invalid format\n", linenum);
                        return 1;
                }

                /* Must be a text symbol */
                symtype = tolower(symtype);
                if (symtype != 't' && symtype != 'w')
                        continue;

                if (func_count == alloced) {
                        alloced += 256;
                        func_list = realloc(func_list,
                                        sizeof(struct func_info) * alloced);
                        assert(func_list);
                }
                if (!func_count)
                        start = offset;

                func = &func_list[func_count++];
                memset(func, '\0', sizeof(*func));
                func->offset = offset - start;
                func->name = strdup(symname);
                func->flags = FUNCF_TRACE;      /* trace by default */

                /* Update previous function's code size */
                if (func_count > 1)
                        func[-1].code_size = func->offset - func[-1].offset;
        }
        notice("%d functions found in map file, start addr %lx\n", func_count,
               start);
        text_offset = start;

        return 0;
}

static int read_data(FILE *fin, void *buff, int size)
{
        int err;

        err = fread(buff, 1, size, fin);
        if (!err)
                return 1;
        if (err != size) {
                error("Cannot read trace file at pos %lx\n", ftell(fin));
                return -1;
        }
        return 0;
}

/**
 * find_func_by_offset() - Look up a function by its offset
 *
 * @offset: Offset to search for, from text_base
 * Returns: function, if found, else NULL
 *
 * This does a fast search for a function given its offset from text_base
 *
 */
static struct func_info *find_func_by_offset(uint offset)
{
        struct func_info key, *found;

        key.offset = offset;
        found = bsearch(&key, func_list, func_count, sizeof(struct func_info),
                        h_cmp_offset);

        return found;
}

/**
 * find_caller_by_offset() - finds the function which contains the given offset
 *
 * @offset: Offset to search for, from text_base
 * Returns: function, if found, else NULL
 *
 * If the offset falls between two functions, then it is assumed to belong to
 * the first function (with the lowest offset). This is a way of figuring out
 * which function owns code at a particular offset
 */
static struct func_info *find_caller_by_offset(uint offset)
{
        int low;        /* least function that could be a match */
        int high;       /* greated function that could be a match */
        struct func_info key;

        low = 0;
        high = func_count - 1;
        key.offset = offset;
        while (high > low + 1) {
                int mid = (low + high) / 2;
                int result;

                result = h_cmp_offset(&key, &func_list[mid]);
                if (result > 0)
                        low = mid;
                else if (result < 0)
                        high = mid;
                else
                        return &func_list[mid];
        }

        return low >= 0 ? &func_list[low] : NULL;
}

/**
 * read_calls() - Read the list of calls from the trace data
 *
 * The calls are stored consecutively in the trace output produced by U-Boot
 *
 * @fin: File to read from
 * @count: Number of calls to read
 * Returns: 0 if OK, -1 on error
 */
static int read_calls(FILE *fin, size_t count)
{
        struct trace_call *call_data;
        int i;

        notice("call count: %zu\n", count);
        call_list = (struct trace_call *)calloc(count, sizeof(*call_data));
        if (!call_list) {
                error("Cannot allocate call_list\n");
                return -1;
        }
        call_count = count;

        call_data = call_list;
        for (i = 0; i < count; i++, call_data++) {
                if (read_data(fin, call_data, sizeof(*call_data)))
                        return -1;
        }
        return 0;
}

/**
 * read_trace() - Read the U-Boot trace file
 *
 * Read in the calls from the trace file. The function list is ignored at
 * present
 *
 * @fin: File to read
 * Returns 0 if OK, non-zero on error
 */
static int read_trace(FILE *fin)
{
        struct trace_output_hdr hdr;

        while (!feof(fin)) {
                int err;

                err = read_data(fin, &hdr, sizeof(hdr));
                if (err == 1)
                        break; /* EOF */
                else if (err)
                        return 1;
                text_base = hdr.text_base;

                switch (hdr.type) {
                case TRACE_CHUNK_FUNCS:
                        /* Ignored at present */
                        break;

                case TRACE_CHUNK_CALLS:
                        if (read_calls(fin, hdr.rec_count))
                                return 1;
                        break;
                }
        }
        return 0;
}

/**
 * read_map_file() - Read the System.map file
 *
 * This reads the file into the func_list array
 *
 * @fname: Filename to read
 * Returns 0 if OK, non-zero on error
 */
static int read_map_file(const char *fname)
{
        FILE *fmap;
        int err = 0;

        fmap = fopen(fname, "r");
        if (!fmap) {
                error("Cannot open map file '%s'\n", fname);
                return 1;
        }
        if (fmap) {
                err = read_system_map(fmap);
                fclose(fmap);
        }
        return err;
}

/**
 * read_trace_file() - Open and read the U-Boot trace file
 *
 * Read in the calls from the trace file. The function list is ignored at
 * present
 *
 * @fin: File to read
 * Returns 0 if OK, non-zero on error
 */
static int read_trace_file(const char *fname)
{
        FILE *fprof;
        int err;

        fprof = fopen(fname, "rb");
        if (!fprof) {
                error("Cannot open trace data file '%s'\n",
                      fname);
                return 1;
        } else {
                err = read_trace(fprof);
                fclose(fprof);
                if (err)
                        return err;
        }
        return 0;
}

static int regex_report_error(regex_t *regex, int err, const char *op,
                              const char *name)
{
        char buf[200];

        regerror(err, regex, buf, sizeof(buf));
        error("Regex error '%s' in %s '%s'\n", buf, op, name);
        return -1;
}

static void check_trace_config_line(struct trace_configline_info *item)
{
        struct func_info *func, *end;
        int err;

        debug("Checking trace config line '%s'\n", item->name);
        for (func = func_list, end = func + func_count; func < end; func++) {
                err = regexec(&item->regex, func->name, 0, NULL, 0);
                debug("   - regex '%s', string '%s': %d\n", item->name,
                      func->name, err);
                if (err == REG_NOMATCH)
                        continue;

                if (err) {
                        regex_report_error(&item->regex, err, "match",
                                           item->name);
                        break;
                }

                /* It matches, so perform the action */
                switch (item->type) {
                case TRACE_LINE_INCLUDE:
                        info("      include %s at %lx\n", func->name,
                             text_offset + func->offset);
                        func->flags |= FUNCF_TRACE;
                        break;

                case TRACE_LINE_EXCLUDE:
                        info("      exclude %s at %lx\n", func->name,
                             text_offset + func->offset);
                        func->flags &= ~FUNCF_TRACE;
                        break;
                }
        }
}

/** check_trace_config() - Check trace-config file, reporting any problems */
static void check_trace_config(void)
{
        struct trace_configline_info *line;

        for (line = trace_config_head; line; line = line->next)
                check_trace_config_line(line);
}

/**
 * read_trace_config() - read the trace-config file
 *
 * This file consists of lines like:
 *
 * include-func <regex>
 * exclude-func <regex>
 *
 * where <regex> is a regular expression matched against function names. It
 * allows some functions to be dropped from the trace when producing ftrace
 * records
 *
 * @fin: File to process
 * Returns: 0 if OK, -1 on error
 */
static int read_trace_config(FILE *fin)
{
        char buff[200];
        int linenum = 0;
        struct trace_configline_info **tailp = &trace_config_head;

        while (fgets(buff, sizeof(buff), fin)) {
                int len = strlen(buff);
                struct trace_configline_info *line;
                char *saveptr;
                char *s, *tok;
                int err;

                linenum++;
                if (len && buff[len - 1] == '\n')
                        buff[len - 1] = '\0';

                /* skip blank lines and comments */
                for (s = buff; *s == ' ' || *s == '\t'; s++)
                        ;
                if (!*s || *s == '#')
                        continue;

                line = (struct trace_configline_info *)calloc(1, sizeof(*line));
                if (!line) {
                        error("Cannot allocate config line\n");
                        return -1;
                }

                tok = strtok_r(s, " \t", &saveptr);
                if (!tok) {
                        error("Invalid trace config data on line %d\n",
                              linenum);
                        return -1;
                }
                if (0 == strcmp(tok, "include-func")) {
                        line->type = TRACE_LINE_INCLUDE;
                } else if (0 == strcmp(tok, "exclude-func")) {
                        line->type = TRACE_LINE_EXCLUDE;
                } else {
                        error("Unknown command in trace config data line %d\n",
                              linenum);
                        return -1;
                }

                tok = strtok_r(NULL, " \t", &saveptr);
                if (!tok) {
                        error("Missing pattern in trace config data line %d\n",
                              linenum);
                        return -1;
                }

                err = regcomp(&line->regex, tok, REG_NOSUB);
                if (err) {
                        int r = regex_report_error(&line->regex, err,
                                                   "compile", tok);
                        free(line);
                        return r;
                }

                /* link this new one to the end of the list */
                line->name = strdup(tok);
                line->next = NULL;
                *tailp = line;
                tailp = &line->next;
        }

        if (!feof(fin)) {
                error("Cannot read from trace config file at position %ld\n",
                      ftell(fin));
                return -1;
        }
        return 0;
}

static int read_trace_config_file(const char *fname)
{
        FILE *fin;
        int err;

        fin = fopen(fname, "r");
        if (!fin) {
                error("Cannot open trace_config file '%s'\n", fname);
                return -1;
        }
        err = read_trace_config(fin);
        fclose(fin);
        return err;
}

/**
 * tputh() - Write a 16-bit little-endian value to a file
 *
 * @fout: File to write to
 * @val: Value to write
 * Returns: number of bytes written (2)
 */
static int tputh(FILE *fout, unsigned int val)
{
        fputc(val, fout);
        fputc(val >> 8, fout);

        return 2;
}

/**
 * tputl() - Write a 32-bit little-endian value to a file
 *
 * @fout: File to write to
 * @val: Value to write
 * Returns: number of bytes written (4)
 */
static int tputl(FILE *fout, ulong val)
{
        fputc(val, fout);
        fputc(val >> 8, fout);
        fputc(val >> 16, fout);
        fputc(val >> 24, fout);

        return 4;
}

/**
 * tputh() - Write a 64-bit little-endian value to a file
 *
 * @fout: File to write to
 * @val: Value to write
 * Returns: number of bytes written (8)
 */
static int tputq(FILE *fout, unsigned long long val)
{
        tputl(fout, val);
        tputl(fout, val >> 32U);

        return 8;
}

/**
 * tputh() - Write a string to a file
 *
 * The string is written without its terminator
 *
 * @fout: File to write to
 * @val: Value to write
 * Returns: number of bytes written
 */
static int tputs(FILE *fout, const char *str)
{
        fputs(str, fout);

        return strlen(str);
}

/**
 * add_str() - add a name string to the string table
 *
 * This is used by the v7 format
 *
 * @tw: Writer context
 * @name: String to write
 * Returns: Updated value of string pointer, or -1 if out of memory
 */
static int add_str(struct twriter *tw, const char *name)
{
        int str_ptr;
        int len;

        len = strlen(name) + 1;
        str_ptr = tw->str_ptr;
        tw->str_ptr += len;

        if (tw->str_ptr > abuf_size(&tw->str_buf)) {
                int new_size;

                new_size = ALIGN(tw->str_ptr, 4096);
                if (!abuf_realloc(&tw->str_buf, new_size))
                        return -1;
        }

        return str_ptr;
}

/**
 * push_len() - Push a new length request onto the stack
 *
 * @tw: Writer context
 * @base: Base position of the length calculation
 * @msg: Indicates the type of caller, for debugging
 * @size: Size of the length value, either 4 bytes or 8
 * Returns number of bytes written to the file (=@size on success), -ve on error
 *
 * This marks a place where a length must be written, covering data that is
 * about to be written. It writes a placeholder value.
 *
 * Once the data is written, calling pop_len() will update the placeholder with
 * the correct length based on how many bytes have been written
 */
static int push_len(struct twriter *tw, int base, const char *msg, int size)
{
        struct tw_len *lp;

        if (tw->len_count >= LEN_STACK_SIZE) {
                fprintf(stderr, "Length-stack overflow: %s\n", msg);
                return -1;
        }
        if (size != 4 && size != 8) {
                fprintf(stderr, "Length-stack invalid size %d: %s\n", size,
                        msg);
                return -1;
        }

        lp = &tw->len_stack[tw->len_count++];
        lp->base = base;
        lp->ptr = tw->ptr;
        lp->size = size;

        return size == 8 ? tputq(tw->fout, 0) : tputl(tw->fout, 0);
}

/**
 * pop_len() - Update a length value once the length is known
 *
 * Pops a value of the length stack and updates the file at that position with
 * the number of bytes written between now and then. Once done, the file is
 * seeked to the current (tw->ptr) position again, so writing can continue as
 * normal.
 *
 * @tw: Writer context
 * @msg: Indicates the type of caller, for debugging
 * Returns 0 if OK, -1 on error
 */
static int pop_len(struct twriter *tw, const char *msg)
{
        struct tw_len *lp;
        int len, ret;

        if (!tw->len_count) {
                fprintf(stderr, "Length-stack underflow: %s\n", msg);
                return -1;
        }

        lp = &tw->len_stack[--tw->len_count];
        if (fseek(tw->fout, lp->ptr, SEEK_SET))
                return -1;
        len = tw->ptr - lp->base;
        ret = lp->size == 8 ? tputq(tw->fout, len) : tputl(tw->fout, len);
        if (ret < 0)
                return -1;
        if (fseek(tw->fout, tw->ptr, SEEK_SET))
                return -1;

        return 0;
}

/**
 * start_header() - Start a v7 section
 *
 * Writes a header in v7 format
 *
 * @tw: Writer context
 * @id: ID of header to write (SECTION_...)
 * @flags: Flags value to write
 * @name: Name of section
 * Returns: number of bytes written
 */
static int start_header(struct twriter *tw, int id, uint flags,
                        const char *name)
{
        int str_id;
        int lptr;
        int base;
        int ret;

        base = tw->ptr + 16;
        lptr = 0;
        lptr += tputh(tw->fout, id);
        lptr += tputh(tw->fout, flags);
        str_id = add_str(tw, name);
        if (str_id < 0)
                return -1;
        lptr += tputl(tw->fout, str_id);

        /* placeholder for size */
        ret = push_len(tw, base, "v7 header", 8);
        if (ret < 0)
                return -1;
        lptr += ret;

        return lptr;
}

/**
 * start_page() - Start a new page of output data
 *
 * The output is arranged in 4KB pages with a base timestamp at the start of
 * each. This starts a new page, making sure it is aligned to 4KB in the output
 * file.
 *
 * @tw: Writer context
 * @timestamp: Base timestamp for the page
 */
static int start_page(struct twriter *tw, ulong timestamp)
{
        int start;
        int ret;

        /* move to start of next page */
        start = ALIGN(tw->ptr, TRACE_PAGE_SIZE);
        ret = fseek(tw->fout, start, SEEK_SET);
        if (ret < 0) {
                fprintf(stderr, "Cannot seek to page start\n");
                return -1;
        }
        tw->ptr = start;

        /* page header */
        tw->ptr += tputq(tw->fout, timestamp);
        ret = push_len(tw, start + 16, "page", 8);
        if (ret < 0)
                return ret;
        tw->ptr += ret;

        return 0;
}

/**
 * finish_page() - finish a page
 *
 * Sets the lengths correctly and moves to the start of the next page
 *
 * @tw: Writer context
 * Returns: 0 on success, -1 on error
 */
static int finish_page(struct twriter *tw)
{
        int ret, end;

        ret = pop_len(tw, "page");
        if (ret < 0)
                return ret;
        end = ALIGN(tw->ptr, TRACE_PAGE_SIZE);

        /*
         * Write a byte so that the data actually makes to the file, in the case
         * that we never write any more pages
         */
        if (tw->ptr != end) {
                if (fseek(tw->fout, end - 1, SEEK_SET)) {
                        fprintf(stderr, "cannot seek to start of next page\n");
                        return -1;
                }
                fputc(0, tw->fout);
                tw->ptr = end;
        }

        return 0;
}

/**
 * output_headers() - Output v6 headers to the file
 *
 * Writes out the various formats so that trace-cmd and kernelshark can make
 * sense of the data
 *
 * This updates tw->ptr as it goes
 *
 * @tw: Writer context
 * Returns: 0 on success, -ve on error
 */
static int output_headers(struct twriter *tw)
{
        FILE *fout = tw->fout;
        char str[800];
        int len, ret;

        tw->ptr += fprintf(fout, "%c%c%ctracing6%c%c%c", 0x17, 0x08, 0x44,
                           0 /* terminator */, 0 /* little endian */,
                           4 /* 32-bit long values */);

        /* host-machine page size 4KB */
        tw->ptr += tputl(fout, 4 << 10);

        tw->ptr += fprintf(fout, "header_page%c", 0);

        snprintf(str, sizeof(str),
                 "\tfield: u64 timestamp;\toffset:0;\tsize:8;\tsigned:0;\n"
                 "\tfield: local_t commit;\toffset:8;\tsize:8;\tsigned:1;\n"
                 "\tfield: int overwrite;\toffset:8;\tsize:1;\tsigned:1;\n"
                 "\tfield: char data;\toffset:16;\tsize:4080;\tsigned:1;\n");
        len = strlen(str);
        tw->ptr += tputq(fout, len);
        tw->ptr += tputs(fout, str);

        if (VERSION7) {
                /* no compression */
                tw->ptr += fprintf(fout, "none%cversion%c\n", 0, 0);

                ret = start_header(tw, SECTION_OPTIONS, 0, "options");
                if (ret < 0) {
                        fprintf(stderr, "Cannot start option header\n");
                        return -1;
                }
                tw->ptr += ret;
                tw->ptr += tputh(fout, OPTION_DONE);
                tw->ptr += tputl(fout, 8);
                tw->ptr += tputl(fout, 0);
                ret = pop_len(tw, "t7 header");
                if (ret < 0) {
                        fprintf(stderr, "Cannot finish option header\n");
                        return -1;
                }
        }

        tw->ptr += fprintf(fout, "header_event%c", 0);
        snprintf(str, sizeof(str),
                 "# compressed entry header\n"
                 "\ttype_len    :    5 bits\n"
                 "\ttime_delta  :   27 bits\n"
                 "\tarray       :   32 bits\n"
                 "\n"
                 "\tpadding     : type == 29\n"
                 "\ttime_extend : type == 30\n"
                 "\ttime_stamp : type == 31\n"
                 "\tdata max type_len  == 28\n");
        len = strlen(str);
        tw->ptr += tputq(fout, len);
        tw->ptr += tputs(fout, str);

        /* number of ftrace-event-format files */
        tw->ptr += tputl(fout, 3);

        snprintf(str, sizeof(str),
                 "name: function\n"
                 "ID: 1\n"
                 "format:\n"
                 "\tfield:unsigned short common_type;\toffset:0;\tsize:2;\tsigned:0;\n"
                 "\tfield:unsigned char common_flags;\toffset:2;\tsize:1;\tsigned:0;\n"
                 "\tfield:unsigned char common_preempt_count;\toffset:3;\tsize:1;signed:0;\n"
                 "\tfield:int common_pid;\toffset:4;\tsize:4;\tsigned:1;\n"
                 "\n"
                 "\tfield:unsigned long ip;\toffset:8;\tsize:8;\tsigned:0;\n"
                 "\tfield:unsigned long parent_ip;\toffset:16;\tsize:8;\tsigned:0;\n"
                 "\n"
                 "print fmt: \" %%ps <-- %%ps\", (void *)REC->ip, (void *)REC->parent_ip\n");
        len = strlen(str);
        tw->ptr += tputq(fout, len);
        tw->ptr += tputs(fout, str);

        snprintf(str, sizeof(str),
                 "name: funcgraph_entry\n"
                 "ID: 11\n"
                 "format:\n"
                 "\tfield:unsigned short common_type;\toffset:0;\tsize:2;\tsigned:0;\n"
                 "\tfield:unsigned char common_flags;\toffset:2;\tsize:1;\tsigned:0;\n"
                 "\tfield:unsigned char common_preempt_count;\toffset:3;\tsize:1;signed:0;\n"
                 "\tfield:int common_pid;\toffset:4;\tsize:4;\tsigned:1;\n"
                 "\n"
                 "\tfield:unsigned long func;\toffset:8;\tsize:8;\tsigned:0;\n"
                 "\tfield:int depth;\toffset:16;\tsize:4;\tsigned:1;\n"
                "\n"
                 "print fmt: \"--> %%ps (%%d)\", (void *)REC->func, REC->depth\n");
        len = strlen(str);
        tw->ptr += tputq(fout, len);
        tw->ptr += tputs(fout, str);

        snprintf(str, sizeof(str),
                 "name: funcgraph_exit\n"
                 "ID: 10\n"
                 "format:\n"
                 "\tfield:unsigned short common_type;\toffset:0;\tsize:2;\tsigned:0;\n"
                 "\tfield:unsigned char common_flags;\toffset:2;\tsize:1;\tsigned:0;\n"
                 "\tfield:unsigned char common_preempt_count;\toffset:3;\tsize:1;signed:0;\n"
                 "\tfield:int common_pid;\toffset:4;\tsize:4;\tsigned:1;\n"
                 "\n"
                 "\tfield:unsigned long func;\toffset:8;\tsize:8;\tsigned:0;\n"
                 "\tfield:int depth;\toffset:16;\tsize:4;\tsigned:1;\n"
                 "\tfield:unsigned int overrun;\toffset:20;\tsize:4;\tsigned:0;\n"
                 "\tfield:unsigned long long calltime;\toffset:24;\tsize:8;\tsigned:0;\n"
                 "\tfield:unsigned long long rettime;\toffset:32;\tsize:8;\tsigned:0;\n"
                 "\n"
                 "print fmt: \"<-- %%ps (%%d) (start: %%llx  end: %%llx) over: %%d\", (void *)REC->func, REC->depth, REC->calltime, REC->rettime, REC->depth\n");
        len = strlen(str);
        tw->ptr += tputq(fout, len);
        tw->ptr += tputs(fout, str);

        return 0;
}

/**
 * write_symbols() - Write the symbols out
 *
 * Writes the symbol information in the following format to mimic the Linux
 * /proc/kallsyms file:
 *
 * <address> T <name>
 *
 * This updates tw->ptr as it goes
 *
 * @tw: Writer context
 * Returns: 0 on success, -ve on error
 */
static int write_symbols(struct twriter *tw)
{
        char str[200];
        int ret, i;

        /* write symbols */
        ret = push_len(tw, tw->ptr + 4, "syms", 4);
        if (ret < 0)
                return -1;
        tw->ptr += ret;
        for (i = 0; i < func_count; i++) {
                struct func_info *func = &func_list[i];

                snprintf(str, sizeof(str), "%016lx T %s\n",
                         text_offset + func->offset, func->name);
                tw->ptr += tputs(tw->fout, str);
        }
        ret = pop_len(tw, "syms");
        if (ret < 0)
                return -1;
        tw->ptr += ret;

        return 0;
}

/**
 * write_options() - Write the options out
 *
 * Writes various options which are needed or useful. We use OPTION_TSC2NSEC
 * to indicates that values in the output need to be multiplied by 1000 since
 * U-Boot's trace values are in microseconds.
 *
 * This updates tw->ptr as it goes
 *
 * @tw: Writer context
 * Returns: 0 on success, -ve on error
 */
static int write_options(struct twriter *tw)
{
        FILE *fout = tw->fout;
        char str[200];
        int len;

        /* trace_printk, 0 for now */
        tw->ptr += tputl(fout, 0);

        /* processes */
        snprintf(str, sizeof(str), "%d u-boot\n", TRACE_PID);
        len = strlen(str);
        tw->ptr += tputq(fout, len);
        tw->ptr += tputs(fout, str);

        /* number of CPUs */
        tw->ptr += tputl(fout, 1);

        tw->ptr += fprintf(fout, "options  %c", 0);

        /* traceclock */
        tw->ptr += tputh(fout, OPTION_TRACECLOCK);
        tw->ptr += tputl(fout, 0);

        /* uname */
        tw->ptr += tputh(fout, OPTION_UNAME);
        snprintf(str, sizeof(str), "U-Boot");
        len = strlen(str);
        tw->ptr += tputl(fout, len);
        tw->ptr += tputs(fout, str);

        /* version */
        tw->ptr += tputh(fout, OPTION_VERSION);
        snprintf(str, sizeof(str), "unknown");
        len = strlen(str);
        tw->ptr += tputl(fout, len);
        tw->ptr += tputs(fout, str);

        /* trace ID */
        tw->ptr += tputh(fout, OPTION_TRACEID);
        tw->ptr += tputl(fout, 8);
        tw->ptr += tputq(fout, 0x123456780abcdef0);

        /* time conversion */
        tw->ptr += tputh(fout, OPTION_TSC2NSEC);
        tw->ptr += tputl(fout, 16);
        tw->ptr += tputl(fout, 1000);   /* multiplier */
        tw->ptr += tputl(fout, 0);      /* shift */
        tw->ptr += tputq(fout, 0);      /* offset */

        /* cpustat - bogus data for now, but at least it mentions the CPU */
        tw->ptr += tputh(fout, OPTION_CPUSTAT);
        snprintf(str, sizeof(str),
                 "CPU: 0\n"
                 "entries: 100\n"
                 "overrun: 43565\n"
                 "commit overrun: 0\n"
                 "bytes: 3360\n"
                 "oldest event ts: 963732.447752\n"
                 "now ts: 963832.146824\n"
                 "dropped events: 0\n"
                 "read events: 42379\n");
        len = strlen(str);
        tw->ptr += tputl(fout, len);
        tw->ptr += tputs(fout, str);

        tw->ptr += tputh(fout, OPTION_DONE);

        return 0;
}

/**
 * calc_min_depth() - Calculate the minimum call depth from the call list
 *
 * Starting with a depth of 0, this works through the call list, adding 1 for
 * each function call and subtracting 1 for each function return. Most likely
 * the value ends up being negative, since the trace does not start at the
 * very top of the call stack, e.g. main(), but some function called by that.
 *
 * This value can be used to calculate the depth value for the first call,
 * such that it never goes negative for subsequent returns.
 *
 * Returns: minimum call depth (e.g. -2)
 */
static int calc_min_depth(void)
{
        struct trace_call *call;
        int depth, min_depth, i;

        /* Calculate minimum depth */
        depth = 0;
        min_depth = 0;
        for (i = 0, call = call_list; i < call_count; i++, call++) {
                switch (TRACE_CALL_TYPE(call)) {
                case FUNCF_ENTRY:
                        depth++;
                        break;
                case FUNCF_EXIT:
                        depth--;
                        if (depth < min_depth)
                                min_depth = depth;
                        break;
                }
        }

        return min_depth;
}

/**
 * write_pages() - Write the pages of trace data
 *
 * This works through all the calls, writing out as many pages of data as are
 * needed.
 *
 * @tw: Writer context
 * @out_format: Output format to use
 * @missing_countp: Returns number of missing functions (not found in function
 * list)
 * @skip_countp: Returns number of skipped functions (excluded from trace)
 *
 * Returns: 0 on success, -ve on error
 */
static int write_pages(struct twriter *tw, enum out_format_t out_format,
                       int *missing_countp, int *skip_countp)
{
        ulong func_stack[MAX_STACK_DEPTH];
        int stack_ptr;  /* next free position in stack */
        int upto, depth, page_upto, i;
        int missing_count = 0, skip_count = 0;
        struct trace_call *call;
        ulong last_timestamp;
        FILE *fout = tw->fout;
        int last_delta = 0;
        int err_count;
        bool in_page;

        in_page = false;
        last_timestamp = 0;
        upto = 0;
        page_upto = 0;
        err_count = 0;

        /* maintain a stack of start times for calling functions */
        stack_ptr = 0;

        /*
         * The first thing in the trace may not be the top-level function, so
         * set the initial depth so that no function goes below depth 0
         */
        depth = -calc_min_depth();
        for (i = 0, call = call_list; i < call_count; i++, call++) {
                bool entry = TRACE_CALL_TYPE(call) == FUNCF_ENTRY;
                struct func_info *func;
                ulong timestamp;
                uint rec_words;
                int delta;

                func = find_func_by_offset(call->func);
                if (!func) {
                        warn("Cannot find function at %lx\n",
                             text_offset + call->func);
                        missing_count++;
                        if (missing_count > 20) {
                                /* perhaps trace does not match System.map */
                                fprintf(stderr, "Too many missing functions\n");
                                return -1;
                        }
                        continue;
                }

                if (!(func->flags & FUNCF_TRACE)) {
                        debug("Funcion '%s' is excluded from trace\n",
                              func->name);
                        skip_count++;
                        continue;
                }

                if (out_format == OUT_FMT_FUNCTION)
                        rec_words = 6;
                else /* 2 header words and then 3 or 8 others */
                        rec_words = 2 + (entry ? 3 : 8);

                /* convert timestamp from us to ns */
                timestamp = call->flags & FUNCF_TIMESTAMP_MASK;
                if (in_page) {
                        if (page_upto + rec_words * 4 > TRACE_PAGE_SIZE) {
                                if (finish_page(tw))
                                        return -1;
                                in_page = false;
                        }
                }
                if (!in_page) {
                        if (start_page(tw, timestamp))
                                return -1;
                        in_page = true;
                        last_timestamp = timestamp;
                        last_delta = 0;
                        page_upto = tw->ptr & TRACE_PAGE_MASK;
                        if (_DEBUG) {
                                fprintf(stderr,
                                        "new page, last_timestamp=%ld, upto=%d\n",
                                        last_timestamp, upto);
                        }
                }

                delta = timestamp - last_timestamp;
                if (delta < 0) {
                        fprintf(stderr, "Time went backwards\n");
                        err_count++;
                }

                if (err_count > 20) {
                        fprintf(stderr, "Too many errors, giving up\n");
                        return -1;
                }

                if (delta > 0x07fffff) {
                        /*
                         * hard to imagine how this could happen since it means
                         * that no function calls were made for a long time
                         */
                        fprintf(stderr, "cannot represent time delta %x\n",
                                delta);
                        return -1;
                }

                if (out_format == OUT_FMT_FUNCTION) {
                        struct func_info *caller_func;

                        if (_DEBUG) {
                                fprintf(stderr, "%d: delta=%d, stamp=%ld\n",
                                        upto, delta, timestamp);
                                fprintf(stderr,
                                        "   last_delta %x to %x: last_timestamp=%lx, "
                                        "timestamp=%lx, call->flags=%x, upto=%d\n",
                                        last_delta, delta, last_timestamp,
                                        timestamp, call->flags, upto);
                        }

                        /* type_len is 6, meaning 4 * 6 = 24 bytes */
                        tw->ptr += tputl(fout, rec_words | (uint)delta << 5);
                        tw->ptr += tputh(fout, TRACE_FN);
                        tw->ptr += tputh(fout, 0);      /* flags */
                        tw->ptr += tputl(fout, TRACE_PID);      /* PID */
                        /* function */
                        tw->ptr += tputq(fout, text_offset + func->offset);
                        caller_func = find_caller_by_offset(call->caller);
                        /* caller */
                        tw->ptr += tputq(fout,
                                         text_offset + caller_func->offset);
                } else {
                        tw->ptr += tputl(fout, rec_words | delta << 5);
                        tw->ptr += tputh(fout, entry ? TRACE_GRAPH_ENT
                                                : TRACE_GRAPH_RET);
                        tw->ptr += tputh(fout, 0);      /* flags */
                        tw->ptr += tputl(fout, TRACE_PID); /* PID */
                        /* function */
                        tw->ptr += tputq(fout, text_offset + func->offset);
                        tw->ptr += tputl(fout, depth); /* depth */
                        if (entry) {
                                depth++;
                                if (stack_ptr < MAX_STACK_DEPTH)
                                        func_stack[stack_ptr] = timestamp;
                                stack_ptr++;
                        } else {
                                ulong func_duration = 0;

                                depth--;
                                if (stack_ptr && stack_ptr <= MAX_STACK_DEPTH) {
                                        ulong start = func_stack[--stack_ptr];

                                        func_duration = timestamp - start;
                                }
                                tw->ptr += tputl(fout, 0);      /* overrun */
                                tw->ptr += tputq(fout, 0);      /* calltime */
                                /* rettime */
                                tw->ptr += tputq(fout, func_duration);
                        }
                }

                last_delta = delta;
                last_timestamp = timestamp;
                page_upto += 4 + rec_words * 4;
                upto++;
                if (stack_ptr == MAX_STACK_DEPTH)
                        break;
        }
        if (in_page && finish_page(tw))
                return -1;
        *missing_countp = missing_count;
        *skip_countp = skip_count;

        return 0;
}

/**
 * write_flyrecord() - Write the flyrecord information
 *
 * Writes the header and pages of data for the "flyrecord" section. It also
 * writes out the counter-type info, selecting "[local]"
 *
 * @tw: Writer context
 * @out_format: Output format to use
 * @missing_countp: Returns number of missing functions (not found in function
 * list)
 * @skip_countp: Returns number of skipped functions (excluded from trace)
 *
 * Returns: 0 on success, -ve on error
 */
static int write_flyrecord(struct twriter *tw, enum out_format_t out_format,
                           int *missing_countp, int *skip_countp)
{
        unsigned long long start, start_ofs, len;
        int ret;
        FILE *fout = tw->fout;
        char str[200];

        /* Record start pointer */
        start_ofs = tw->ptr;
        debug("Start of flyrecord header at: 0x%llx\n", start_ofs);

        tw->ptr += fprintf(fout, "flyrecord%c", 0);

        /* flyrecord\0 - allocated 10 bytes */
        start_ofs += 10;

        /*
         * 8 bytes that are a 64-bit word containing the offset into the file
         * that holds the data for the CPU.
         *
         * 8 bytes that are a 64-bit word containing the size of the CPU
         * data at that offset.
         */
        start_ofs += 16;

        snprintf(str, sizeof(str),
                 "[local] global counter uptime perf mono mono_raw boot x86-tsc\n");
        len = strlen(str);

        /* trace clock length - 8 bytes */
        start_ofs += 8;
        /* trace clock data */
        start_ofs += len;

        debug("Calculated flyrecord header end at: 0x%llx, trace clock len: 0x%llx\n",
              start_ofs, len);

        /* trace data */
        start = ALIGN(start_ofs, TRACE_PAGE_SIZE);
        tw->ptr += tputq(fout, start);

        /* use a placeholder for the size */
        ret = push_len(tw, start, "flyrecord", 8);
        if (ret < 0)
                return -1;
        tw->ptr += ret;

        tw->ptr += tputq(fout, len);
        tw->ptr += tputs(fout, str);

        debug("End of flyrecord header at: 0x%x, offset: 0x%llx\n",
              tw->ptr, start);

        debug("trace text base %lx, map file %lx\n", text_base, text_offset);

        ret = write_pages(tw, out_format, missing_countp, skip_countp);
        if (ret < 0) {
                fprintf(stderr, "Cannot output pages\n");
                return -1;
        }

        ret = pop_len(tw, "flyrecord");
        if (ret < 0) {
                fprintf(stderr, "Cannot finish flyrecord header\n");
                return -1;
        }

        return 0;
}

/**
 * make_ftrace() - Write out an ftrace file
 *
 * See here for format:
 *
 * https://github.com/rostedt/trace-cmd/blob/master/Documentation/trace-cmd/trace-cmd.dat.v7.5.txt
 *
 * @fout: Output file
 * @out_format: Output format to use
 * Returns: 0 on success, -ve on error
 */
static int make_ftrace(FILE *fout, enum out_format_t out_format)
{
        int missing_count, skip_count;
        struct twriter tws, *tw = &tws;
        int ret;

        memset(tw, '\0', sizeof(*tw));
        abuf_init(&tw->str_buf);
        tw->fout = fout;

        tw->ptr = 0;
        ret = output_headers(tw);
        if (ret < 0) {
                fprintf(stderr, "Cannot output headers\n");
                return -1;
        }
        /* number of event systems files */
        tw->ptr += tputl(fout, 0);

        ret = write_symbols(tw);
        if (ret < 0) {
                fprintf(stderr, "Cannot write symbols\n");
                return -1;
        }

        ret = write_options(tw);
        if (ret < 0) {
                fprintf(stderr, "Cannot write options\n");
                return -1;
        }

        ret = write_flyrecord(tw, out_format, &missing_count, &skip_count);
        if (ret < 0) {
                fprintf(stderr, "Cannot write flyrecord\n");
                return -1;
        }

        info("ftrace: %d functions not found, %d excluded\n", missing_count,
             skip_count);

        return 0;
}

/**
 * create_node() - Create a new node in the flamegraph tree
 *
 * @msg: Message to use for debugging if something goes wrong
 * Returns: Pointer to newly created node, or NULL on error
 */
static struct flame_node *create_node(const char *msg)
{
        struct flame_node *node;

        node = calloc(1, sizeof(*node));
        if (!node) {
                fprintf(stderr, "Out of memory for %s\n", msg);
                return NULL;
        }
        INIT_LIST_HEAD(&node->child_head);

        return node;
}

/**
 * process_call(): Add a call to the flamegraph info
 *
 * For function calls, if this call stack has been seen before, this increments
 * the call count, creating a new node if needed.
 *
 * For function returns, it adds up the time spent in this call stack,
 * subtracting the time spent by child functions.
 *
 * @state: Current flamegraph state
 * @entry: true if this is a function entry, false if a function exit
 * @timestamp: Timestamp from the trace file (in microseconds)
 * @func: Function that was called/returned from
 *
 * Returns: 0 on success, -ve on error
 */
static int process_call(struct flame_state *state, bool entry, ulong timestamp,
                        struct func_info *func)
{
        struct flame_node *node = state->node;
        int stack_ptr = state->stack_ptr;

        if (entry) {
                struct flame_node *child, *chd;

                /* see if we have this as a child node already */
                child = NULL;
                list_for_each_entry(chd, &node->child_head, sibling_node) {
                        if (chd->func == func) {
                                child = chd;
                                break;
                        }
                }
                if (!child) {
                        /* create a new node */
                        child = create_node("child");
                        if (!child)
                                return -1;
                        list_add_tail(&child->sibling_node, &node->child_head);
                        child->func = func;
                        child->parent = node;
                        state->nodes++;
                }
                debug("entry %s: move from %s to %s\n", func->name,
                      node->func ? node->func->name : "(root)",
                      child->func->name);
                child->count++;
                if (stack_ptr < MAX_STACK_DEPTH) {
                        state->stack[stack_ptr].timestamp = timestamp;
                        state->stack[stack_ptr].child_total = 0;
                }
                debug("%d: %20s: entry at %ld\n", stack_ptr, func->name,
                      timestamp);
                stack_ptr++;
                node = child;
        } else if (node->parent) {
                ulong total_duration = 0, child_duration = 0;
                struct stack_info *stk;

                debug("exit  %s: move from %s to %s\n", func->name,
                      node->func->name, node->parent->func ?
                      node->parent->func->name : "(root)");
                if (stack_ptr && stack_ptr <= MAX_STACK_DEPTH) {
                        stk = &state->stack[--stack_ptr];

                        /*
                         * get total duration of the function which just
                         * exited
                         */
                        total_duration = timestamp - stk->timestamp;
                        child_duration = stk->child_total;

                        if (stack_ptr)
                                state->stack[stack_ptr - 1].child_total += total_duration;

                        debug("%d: %20s: exit at %ld, total %ld, child %ld, child_total=%ld\n",
                              stack_ptr, func->name, timestamp,
                              total_duration, child_duration,
                              stk->child_total);
                }
                node->duration += total_duration - child_duration;
                node = node->parent;
        }

        state->stack_ptr = stack_ptr;
        state->node = node;

        return 0;
}

/**
 * make_flame_tree() - Create a tree of stack traces
 *
 * Set up a tree, with the root node having the top-level functions as children
 * and the leaf nodes being leaf functions. Each node has a count of how many
 * times this function appears in the trace
 *
 * @out_format: Output format to use
 * @treep: Returns the resulting flamegraph tree
 * Returns: 0 on success, -ve on error
 */
static int make_flame_tree(enum out_format_t out_format,
                           struct flame_node **treep)
{
        struct flame_state state;
        struct flame_node *tree;
        struct trace_call *call;
        int i;

        /* maintain a stack of start times, etc. for 'calling' functions */
        state.stack_ptr = 0;

        tree = create_node("tree");
        if (!tree)
                return -1;
        state.node = tree;
        state.nodes = 0;

        for (i = 0, call = call_list; i < call_count; i++, call++) {
                bool entry = TRACE_CALL_TYPE(call) == FUNCF_ENTRY;
                ulong timestamp = call->flags & FUNCF_TIMESTAMP_MASK;
                struct func_info *func;

                func = find_func_by_offset(call->func);
                if (!func) {
                        warn("Cannot find function at %lx\n",
                             text_offset + call->func);
                        continue;
                }

                if (process_call(&state, entry, timestamp, func))
                        return -1;
        }
        fprintf(stderr, "%d nodes\n", state.nodes);
        *treep = tree;

        return 0;
}

/**
 * output_tree() - Output a flamegraph tree
 *
 * Writes the tree out to a file in a format suitable for flamegraph.pl
 *
 * This works by maintaining a string shared across all recursive calls. The
 * function name for this node is added to the existing string, to make up the
 * full call-stack description. For example, on entry, @str might contain:
 *
 *    "initf_bootstage;bootstage_mark_name"
 *                                        ^ @base
 *
 * with @base pointing to the \0 at the end of the string. This function adds
 * a ';' following by the name of the current function, e.g. "timer_get_boot_us"
 * as well as the output value, to get the full line:
 *
 * initf_bootstage;bootstage_mark_name;timer_get_boot_us 123
 *
 * @fout: Output file
 * @out_format: Output format to use
 * @node: Node to output (pass the whole tree at first)
 * @str: String to use to build the output line (e.g. 500 charas long)
 * @maxlen: Maximum length of string
 * @base: Current base position in the string
 * @treep: Returns the resulting flamegraph tree
 * Returns 0 if OK, -1 on error
 */
static int output_tree(FILE *fout, enum out_format_t out_format,
                       const struct flame_node *node, char *str, int maxlen,
                       int base)
{
        const struct flame_node *child;
        int pos;

        if (node->count) {
                if (out_format == OUT_FMT_FLAMEGRAPH_CALLS) {
                        fprintf(fout, "%s %d\n", str, node->count);
                } else {
                        /*
                         * Write out the number of microseconds used by this
                         * call stack. Since the time taken by child calls is
                         * subtracted from this total, it can reach 0, meaning
                         * that this function took no time beyond what its
                         * children used. For this case, write 1 rather than 0,
                         * so that this call stack appears in the flamegraph.
                         * This has the effect of inflating the timing slightly,
                         * but only by at most 1 microsecond per function,
                         * assuming that is the timestamp resolution
                         */
                        fprintf(fout, "%s %ld\n", str,
                                node->duration ? node->duration : 1);
                }
        }

        pos = base;
        if (pos)
                str[pos++] = ';';
        list_for_each_entry(child, &node->child_head, sibling_node) {
                int len;

                len = strlen(child->func->name);
                if (pos + len + 1 >= maxlen) {
                        fprintf(stderr, "String too short (%d chars)\n",
                                maxlen);
                        return -1;
                }
                strcpy(str + pos, child->func->name);
                if (output_tree(fout, out_format, child, str, maxlen,
                                pos + len))
                        return -1;
        }

        return 0;
}

/**
 * make_flamegraph() - Write out a flame graph
 *
 * @fout: Output file
 * @out_format: Output format to use, e.g. function counts or timing
 * Returns 0 if OK, -1 on error
 */
static int make_flamegraph(FILE *fout, enum out_format_t out_format)
{
        struct flame_node *tree;
        char str[500];

        if (make_flame_tree(out_format, &tree))
                return -1;

        *str = '\0';
        if (output_tree(fout, out_format, tree, str, sizeof(str), 0))
                return -1;

        return 0;
}

/**
 * prof_tool() - Performs requested action
 *
 * @argc: Number of arguments (used to obtain the command
 * @argv: List of arguments
 * @trace_fname: Filename of input file (trace data from U-Boot)
 * @map_fname: Filename of map file (System.map from U-Boot)
 * @trace_config_fname: Trace-configuration file, or NULL if none
 * @out_fname: Output filename
 */
static int 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)
{
        int err = 0;

        if (read_map_file(map_fname))
                return -1;
        if (trace_fname && read_trace_file(trace_fname))
                return -1;
        if (trace_config_fname && read_trace_config_file(trace_config_fname))
                return -1;

        check_trace_config();

        for (; argc; argc--, argv++) {
                const char *cmd = *argv;

                if (!strcmp(cmd, "dump-ftrace")) {
                        FILE *fout;

                        if (out_format != OUT_FMT_FUNCTION &&
                            out_format != OUT_FMT_FUNCGRAPH)
                                out_format = OUT_FMT_FUNCTION;
                        fout = fopen(out_fname, "w");
                        if (!fout) {
                                fprintf(stderr, "Cannot write file '%s'\n",
                                        out_fname);
                                return -1;
                        }
                        err = make_ftrace(fout, out_format);
                        fclose(fout);
                } else if (!strcmp(cmd, "dump-flamegraph")) {
                        FILE *fout;

                        if (out_format != OUT_FMT_FLAMEGRAPH_CALLS &&
                            out_format != OUT_FMT_FLAMEGRAPH_TIMING)
                                out_format = OUT_FMT_FLAMEGRAPH_CALLS;
                        fout = fopen(out_fname, "w");
                        if (!fout) {
                                fprintf(stderr, "Cannot write file '%s'\n",
                                        out_fname);
                                return -1;
                        }
                        err = make_flamegraph(fout, out_format);
                        fclose(fout);
                } else {
                        warn("Unknown command '%s'\n", cmd);
                }
        }

        return err;
}

int main(int argc, char *argv[])
{
        enum out_format_t out_format = OUT_FMT_DEFAULT;
        const char *map_fname = "System.map";
        const char *trace_fname = NULL;
        const char *config_fname = NULL;
        const char *out_fname = NULL;
        int opt;

        verbose = 2;
        while ((opt = getopt(argc, argv, "c:f:m:o:t:v:")) != -1) {
                switch (opt) {
                case 'c':
                        config_fname = optarg;
                        break;
                case 'f':
                        if (!strcmp("function", optarg)) {
                                out_format = OUT_FMT_FUNCTION;
                        } else if (!strcmp("funcgraph", optarg)) {
                                out_format = OUT_FMT_FUNCGRAPH;
                        } else if (!strcmp("calls", optarg)) {
                                out_format = OUT_FMT_FLAMEGRAPH_CALLS;
                        } else if (!strcmp("timing", optarg)) {
                                out_format = OUT_FMT_FLAMEGRAPH_TIMING;
                        } else {
                                fprintf(stderr,
                                        "Invalid format: use function, funcgraph, calls, timing\n");
                                exit(1);
                        }
                        break;
                case 'm':
                        map_fname = optarg;
                        break;
                case 'o':
                        out_fname = optarg;
                        break;
                case 't':
                        trace_fname = optarg;
                        break;
                case 'v':
                        verbose = atoi(optarg);
                        break;
                default:
                        usage();
                }
        }
        argc -= optind; argv += optind;
        if (argc < 1)
                usage();

        if (!out_fname || !map_fname || !trace_fname) {
                fprintf(stderr,
                        "Must provide trace data, System.map file and output file\n");
                usage();
        }

        debug("Debug enabled\n");
        return prof_tool(argc, argv, trace_fname, map_fname, config_fname,
                         out_fname, out_format);
}