debug.c

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// SPDX-License-Identifier: GPL-2.0
/* For general debugging purposes */

#include "../perf.h"

#include <inttypes.h>
#include <string.h>
#include <stdarg.h>
#include <stdio.h>
#include <sys/wait.h>
#include <api/debug.h>
#include <linux/time64.h>
#ifdef HAVE_BACKTRACE_SUPPORT
#include <execinfo.h>
#endif
#include "cache.h"
#include "color.h"
#include "event.h"
#include "debug.h"
#include "print_binary.h"
#include "util.h"
#include "target.h"

#include "sane_ctype.h"

int verbose;
bool dump_trace = false, quiet = false;
int debug_ordered_events;
static int redirect_to_stderr;
int debug_data_convert;

int veprintf(int level, int var, const char *fmt, va_list args)
{
    int ret = 0;

    if (var >= level) {
        if (use_browser >= 1 && !redirect_to_stderr)
            ui_helpline__vshow(fmt, args);
        else
            ret = vfprintf(stderr, fmt, args);
    }

    return ret;
}

int eprintf(int level, int var, const char *fmt, ...)
{
    va_list args;
    int ret;

    va_start(args, fmt);
    ret = veprintf(level, var, fmt, args);
    va_end(args);

    return ret;
}

static int veprintf_time(u64 t, const char *fmt, va_list args)
{
    int ret = 0;
    u64 secs, usecs, nsecs = t;

    secs   = nsecs / NSEC_PER_SEC;
    nsecs -= secs  * NSEC_PER_SEC;
    usecs  = nsecs / NSEC_PER_USEC;

    ret = fprintf(stderr, "[%13" PRIu64 ".%06" PRIu64 "] ",
              secs, usecs);
    ret += vfprintf(stderr, fmt, args);
    return ret;
}

int eprintf_time(int level, int var, u64 t, const char *fmt, ...)
{
    int ret = 0;
    va_list args;

    if (var >= level) {
        va_start(args, fmt);
        ret = veprintf_time(t, fmt, args);
        va_end(args);
    }

    return ret;
}

/*
 * Overloading libtraceevent standard info print
 * function, display with -v in perf.
 */
void pr_stat(const char *fmt, ...)
{
    va_list args;

    va_start(args, fmt);
    veprintf(1, verbose, fmt, args);
    va_end(args);
    eprintf(1, verbose, "\n");
}

int dump_printf(const char *fmt, ...)
{
    va_list args;
    int ret = 0;

    if (dump_trace) {
        va_start(args, fmt);
        ret = vprintf(fmt, args);
        va_end(args);
    }

    return ret;
}

static int trace_event_printer(enum binary_printer_ops op,
                   unsigned int val, void *extra, FILE *fp)
{
    const char *color = PERF_COLOR_BLUE;
    union perf_event *event = (union perf_event *)extra;
    unsigned char ch = (unsigned char)val;
    int printed = 0;

    switch (op) {
    case BINARY_PRINT_DATA_BEGIN:
        printed += fprintf(fp, ".");
        printed += color_fprintf(fp, color, "\n. ... raw event: size %d bytes\n",
                     event->header.size);
        break;
    case BINARY_PRINT_LINE_BEGIN:
        printed += fprintf(fp, ".");
        break;
    case BINARY_PRINT_ADDR:
        printed += color_fprintf(fp, color, "  %04x: ", val);
        break;
    case BINARY_PRINT_NUM_DATA:
        printed += color_fprintf(fp, color, " %02x", val);
        break;
    case BINARY_PRINT_NUM_PAD:
        printed += color_fprintf(fp, color, "   ");
        break;
    case BINARY_PRINT_SEP:
        printed += color_fprintf(fp, color, "  ");
        break;
    case BINARY_PRINT_CHAR_DATA:
        printed += color_fprintf(fp, color, "%c",
                  isprint(ch) ? ch : '.');
        break;
    case BINARY_PRINT_CHAR_PAD:
        printed += color_fprintf(fp, color, " ");
        break;
    case BINARY_PRINT_LINE_END:
        printed += color_fprintf(fp, color, "\n");
        break;
    case BINARY_PRINT_DATA_END:
        printed += fprintf(fp, "\n");
        break;
    default:
        break;
    }

    return printed;
}

void trace_event(union perf_event *event)
{
    unsigned char *raw_event = (void *)event;

    if (!dump_trace)
        return;

    print_binary(raw_event, event->header.size, 16,
             trace_event_printer, event);
}

static struct debug_variable {
    const char *name;
    int *ptr;
} debug_variables[] = {
    { .name = "verbose",        .ptr = &verbose },
    { .name = "ordered-events", .ptr = &debug_ordered_events},
    { .name = "stderr",     .ptr = &redirect_to_stderr},
    { .name = "data-convert",   .ptr = &debug_data_convert },
    { .name = NULL, }
};

int perf_debug_option(const char *str)
{
    struct debug_variable *var = &debug_variables[0];
    char *vstr, *s = strdup(str);
    int v = 1;

    vstr = strchr(s, '=');
    if (vstr)
        *vstr++ = 0;

    while (var->name) {
        if (!strcmp(s, var->name))
            break;
        var++;
    }

    if (!var->name) {
        pr_err("Unknown debug variable name '%s'\n", s);
        free(s);
        return -1;
    }

    if (vstr) {
        v = atoi(vstr);
        /*
         * Allow only values in range (0, 10),
         * otherwise set 0.
         */
        v = (v < 0) || (v > 10) ? 0 : v;
    }

    if (quiet)
        v = -1;

    *var->ptr = v;
    free(s);
    return 0;
}

int perf_quiet_option(void)
{
    struct debug_variable *var = &debug_variables[0];

    /* disable all debug messages */
    while (var->name) {
        *var->ptr = -1;
        var++;
    }

    return 0;
}

#define DEBUG_WRAPPER(__n, __l)             \
static int pr_ ## __n ## _wrapper(const char *fmt, ...) \
{                           \
    va_list args;                   \
    int ret;                    \
                            \
    va_start(args, fmt);                \
    ret = veprintf(__l, verbose, fmt, args);    \
    va_end(args);                   \
    return ret;                 \
}

DEBUG_WRAPPER(warning, 0);
DEBUG_WRAPPER(debug, 1);

void perf_debug_setup(void)
{
    libapi_set_print(pr_warning_wrapper, pr_warning_wrapper, pr_debug_wrapper);
}

/* Obtain a backtrace and print it to stdout. */
#ifdef HAVE_BACKTRACE_SUPPORT
void dump_stack(void)
{
    void *array[16];
    size_t size = backtrace(array, ARRAY_SIZE(array));
    char **strings = backtrace_symbols(array, size);
    size_t i;

    printf("Obtained %zd stack frames.\n", size);

    for (i = 0; i < size; i++)
        printf("%s\n", strings[i]);

    free(strings);
}
#else
void dump_stack(void) {}
#endif

void sighandler_dump_stack(int sig)
{
    psignal(sig, "perf");
    dump_stack();
    signal(sig, SIG_DFL);
    raise(sig);
}