1 files changed, 802 insertions, 0 deletions

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
new file mode 100644
index 000000000000..7c004b6ef24f
--- /dev/null
+++ b/tools/perf/util/probe-event.c
@@ -0,0 +1,802 @@
+/*
+ * probe-event.c : perf-probe definition to kprobe_events format converter
+ *
+ * Written by Masami Hiramatsu <mhiramat@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#define _GNU_SOURCE
+#include <sys/utsname.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+#include <limits.h>
+
+#undef _GNU_SOURCE
+#include "event.h"
+#include "string.h"
+#include "strlist.h"
+#include "debug.h"
+#include "cache.h"
+#include "color.h"
+#include "parse-events.h"  /* For debugfs_path */
+#include "probe-event.h"
+
+#define MAX_CMDLEN 256
+#define MAX_PROBE_ARGS 128
+#define PERFPROBE_GROUP "probe"
+
+#define semantic_error(msg ...) die("Semantic error :" msg)
+
+/* If there is no space to write, returns -E2BIG. */
+static int e_snprintf(char *str, size_t size, const char *format, ...)
+        __attribute__((format(printf, 3, 4)));
+
+static int e_snprintf(char *str, size_t size, const char *format, ...)
+{
+        int ret;
+        va_list ap;
+        va_start(ap, format);
+        ret = vsnprintf(str, size, format, ap);
+        va_end(ap);
+        if (ret >= (int)size)
+                ret = -E2BIG;
+        return ret;
+}
+
+void parse_line_range_desc(const char *arg, struct line_range *lr)
+{
+        const char *ptr;
+        char *tmp;
+        /*
+         * <Syntax>
+         * SRC:SLN[+NUM|-ELN]
+         * FUNC[:SLN[+NUM|-ELN]]
+         */
+        ptr = strchr(arg, ':');
+        if (ptr) {
+                lr->start = (unsigned int)strtoul(ptr + 1, &tmp, 0);
+                if (*tmp == '+')
+                        lr->end = lr->start + (unsigned int)strtoul(tmp + 1,
+                                                                    &tmp, 0);
+                else if (*tmp == '-')
+                        lr->end = (unsigned int)strtoul(tmp + 1, &tmp, 0);
+                else
+                        lr->end = 0;
+                pr_debug("Line range is %u to %u\n", lr->start, lr->end);
+                if (lr->end && lr->start > lr->end)
+                        semantic_error("Start line must be smaller"
+                                       " than end line.");
+                if (*tmp != '\0')
+                        semantic_error("Tailing with invalid character '%d'.",
+                                       *tmp);
+                tmp = strndup(arg, (ptr - arg));
+        } else
+                tmp = strdup(arg);
+
+        if (strchr(tmp, '.'))
+                lr->file = tmp;
+        else
+                lr->function = tmp;
+}
+
+/* Check the name is good for event/group */
+static bool check_event_name(const char *name)
+{
+        if (!isalpha(*name) && *name != '_')
+                return false;
+        while (*++name != '\0') {
+                if (!isalpha(*name) && !isdigit(*name) && *name != '_')
+                        return false;
+        }
+        return true;
+}
+
+/* Parse probepoint definition. */
+static void parse_perf_probe_probepoint(char *arg, struct probe_point *pp)
+{
+        char *ptr, *tmp;
+        char c, nc = 0;
+        /*
+         * <Syntax>
+         * perf probe [EVENT=]SRC[:LN|;PTN]
+         * perf probe [EVENT=]FUNC[@SRC][+OFFS|%return|:LN|;PAT]
+         *
+         * TODO:Group name support
+         */
+
+        ptr = strpbrk(arg, ";=@+%");
+        if (ptr && *ptr == '=') {       /* Event name */
+                *ptr = '\0';
+                tmp = ptr + 1;
+                ptr = strchr(arg, ':');
+                if (ptr)        /* Group name is not supported yet. */
+                        semantic_error("Group name is not supported yet.");
+                if (!check_event_name(arg))
+                        semantic_error("%s is bad for event name -it must "
+                                       "follow C symbol-naming rule.", arg);
+                pp->event = strdup(arg);
+                arg = tmp;
+        }
+
+        ptr = strpbrk(arg, ";:+@%");
+        if (ptr) {
+                nc = *ptr;
+                *ptr++ = '\0';
+        }
+
+        /* Check arg is function or file and copy it */
+        if (strchr(arg, '.'))   /* File */
+                pp->file = strdup(arg);
+        else                    /* Function */
+                pp->function = strdup(arg);
+        DIE_IF(pp->file == NULL && pp->function == NULL);
+
+        /* Parse other options */
+        while (ptr) {
+                arg = ptr;
+                c = nc;
+                if (c == ';') { /* Lazy pattern must be the last part */
+                        pp->lazy_line = strdup(arg);
+                        break;
+                }
+                ptr = strpbrk(arg, ";:+@%");
+                if (ptr) {
+                        nc = *ptr;
+                        *ptr++ = '\0';
+                }
+                switch (c) {
+                case ':':       /* Line number */
+                        pp->line = strtoul(arg, &tmp, 0);
+                        if (*tmp != '\0')
+                                semantic_error("There is non-digit char"
+                                               " in line number.");
+                        break;
+                case '+':       /* Byte offset from a symbol */
+                        pp->offset = strtoul(arg, &tmp, 0);
+                        if (*tmp != '\0')
+                                semantic_error("There is non-digit character"
+                                                " in offset.");
+                        break;
+                case '@':       /* File name */
+                        if (pp->file)
+                                semantic_error("SRC@SRC is not allowed.");
+                        pp->file = strdup(arg);
+                        DIE_IF(pp->file == NULL);
+                        break;
+                case '%':       /* Probe places */
+                        if (strcmp(arg, "return") == 0) {
+                                pp->retprobe = 1;
+                        } else  /* Others not supported yet */
+                                semantic_error("%%%s is not supported.", arg);
+                        break;
+                default:
+                        DIE_IF("Program has a bug.");
+                        break;
+                }
+        }
+
+        /* Exclusion check */
+        if (pp->lazy_line && pp->line)
+                semantic_error("Lazy pattern can't be used with line number.");
+
+        if (pp->lazy_line && pp->offset)
+                semantic_error("Lazy pattern can't be used with offset.");
+
+        if (pp->line && pp->offset)
+                semantic_error("Offset can't be used with line number.");
+
+        if (!pp->line && !pp->lazy_line && pp->file && !pp->function)
+                semantic_error("File always requires line number or "
+                               "lazy pattern.");
+
+        if (pp->offset && !pp->function)
+                semantic_error("Offset requires an entry function.");
+
+        if (pp->retprobe && !pp->function)
+                semantic_error("Return probe requires an entry function.");
+
+        if ((pp->offset || pp->line || pp->lazy_line) && pp->retprobe)
+                semantic_error("Offset/Line/Lazy pattern can't be used with "
+                               "return probe.");
+
+        pr_debug("symbol:%s file:%s line:%d offset:%d return:%d lazy:%s\n",
+                 pp->function, pp->file, pp->line, pp->offset, pp->retprobe,
+                 pp->lazy_line);
+}
+
+/* Parse perf-probe event definition */
+void parse_perf_probe_event(const char *str, struct probe_point *pp,
+                            bool *need_dwarf)
+{
+        char **argv;
+        int argc, i;
+
+        *need_dwarf = false;
+
+        argv = argv_split(str, &argc);
+        if (!argv)
+                die("argv_split failed.");
+        if (argc > MAX_PROBE_ARGS + 1)
+                semantic_error("Too many arguments");
+
+        /* Parse probe point */
+        parse_perf_probe_probepoint(argv[0], pp);
+        if (pp->file || pp->line || pp->lazy_line)
+                *need_dwarf = true;
+
+        /* Copy arguments and ensure return probe has no C argument */
+        pp->nr_args = argc - 1;
+        pp->args = zalloc(sizeof(char *) * pp->nr_args);
+        for (i = 0; i < pp->nr_args; i++) {
+                pp->args[i] = strdup(argv[i + 1]);
+                if (!pp->args[i])
+                        die("Failed to copy argument.");
+                if (is_c_varname(pp->args[i])) {
+                        if (pp->retprobe)
+                                semantic_error("You can't specify local"
+                                                " variable for kretprobe");
+                        *need_dwarf = true;
+                }
+        }
+
+        argv_free(argv);
+}
+
+/* Parse kprobe_events event into struct probe_point */
+void parse_trace_kprobe_event(const char *str, struct probe_point *pp)
+{
+        char pr;
+        char *p;
+        int ret, i, argc;
+        char **argv;
+
+        pr_debug("Parsing kprobe_events: %s\n", str);
+        argv = argv_split(str, &argc);
+        if (!argv)
+                die("argv_split failed.");
+        if (argc < 2)
+                semantic_error("Too less arguments.");
+
+        /* Scan event and group name. */
+        ret = sscanf(argv[0], "%c:%a[^/ \t]/%a[^ \t]",
+                     &pr, (float *)(void *)&pp->group,
+                     (float *)(void *)&pp->event);
+        if (ret != 3)
+                semantic_error("Failed to parse event name: %s", argv[0]);
+        pr_debug("Group:%s Event:%s probe:%c\n", pp->group, pp->event, pr);
+
+        pp->retprobe = (pr == 'r');
+
+        /* Scan function name and offset */
+        ret = sscanf(argv[1], "%a[^+]+%d", (float *)(void *)&pp->function,
+                     &pp->offset);
+        if (ret == 1)
+                pp->offset = 0;
+
+        /* kprobe_events doesn't have this information */
+        pp->line = 0;
+        pp->file = NULL;
+
+        pp->nr_args = argc - 2;
+        pp->args = zalloc(sizeof(char *) * pp->nr_args);
+        for (i = 0; i < pp->nr_args; i++) {
+                p = strchr(argv[i + 2], '=');
+                if (p)  /* We don't need which register is assigned. */
+                        *p = '\0';
+                pp->args[i] = strdup(argv[i + 2]);
+                if (!pp->args[i])
+                        die("Failed to copy argument.");
+        }
+
+        argv_free(argv);
+}
+
+/* Synthesize only probe point (not argument) */
+int synthesize_perf_probe_point(struct probe_point *pp)
+{
+        char *buf;
+        char offs[64] = "", line[64] = "";
+        int ret;
+
+        pp->probes[0] = buf = zalloc(MAX_CMDLEN);
+        pp->found = 1;
+        if (!buf)
+                die("Failed to allocate memory by zalloc.");
+        if (pp->offset) {
+                ret = e_snprintf(offs, 64, "+%d", pp->offset);
+                if (ret <= 0)
+                        goto error;
+        }
+        if (pp->line) {
+                ret = e_snprintf(line, 64, ":%d", pp->line);
+                if (ret <= 0)
+                        goto error;
+        }
+
+        if (pp->function)
+                ret = e_snprintf(buf, MAX_CMDLEN, "%s%s%s%s", pp->function,
+                                 offs, pp->retprobe ? "%return" : "", line);
+        else
+                ret = e_snprintf(buf, MAX_CMDLEN, "%s%s", pp->file, line);
+        if (ret <= 0) {
+error:
+                free(pp->probes[0]);
+                pp->probes[0] = NULL;
+                pp->found = 0;
+        }
+        return ret;
+}
+
+int synthesize_perf_probe_event(struct probe_point *pp)
+{
+        char *buf;
+        int i, len, ret;
+
+        len = synthesize_perf_probe_point(pp);
+        if (len < 0)
+                return 0;
+
+        buf = pp->probes[0];
+        for (i = 0; i < pp->nr_args; i++) {
+                ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",
+                                 pp->args[i]);
+                if (ret <= 0)
+                        goto error;
+                len += ret;
+        }
+        pp->found = 1;
+
+        return pp->found;
+error:
+        free(pp->probes[0]);
+        pp->probes[0] = NULL;
+
+        return ret;
+}
+
+int synthesize_trace_kprobe_event(struct probe_point *pp)
+{
+        char *buf;
+        int i, len, ret;
+
+        pp->probes[0] = buf = zalloc(MAX_CMDLEN);
+        if (!buf)
+                die("Failed to allocate memory by zalloc.");
+        ret = e_snprintf(buf, MAX_CMDLEN, "%s+%d", pp->function, pp->offset);
+        if (ret <= 0)
+                goto error;
+        len = ret;
+
+        for (i = 0; i < pp->nr_args; i++) {
+                ret = e_snprintf(&buf[len], MAX_CMDLEN - len, " %s",
+                                 pp->args[i]);
+                if (ret <= 0)
+                        goto error;
+                len += ret;
+        }
+        pp->found = 1;
+
+        return pp->found;
+error:
+        free(pp->probes[0]);
+        pp->probes[0] = NULL;
+
+        return ret;
+}
+
+static int open_kprobe_events(int flags, int mode)
+{
+        char buf[PATH_MAX];
+        int ret;
+
+        ret = e_snprintf(buf, PATH_MAX, "%s/../kprobe_events", debugfs_path);
+        if (ret < 0)
+                die("Failed to make kprobe_events path.");
+
+        ret = open(buf, flags, mode);
+        if (ret < 0) {
+                if (errno == ENOENT)
+                        die("kprobe_events file does not exist -"
+                            " please rebuild with CONFIG_KPROBE_EVENT.");
+                else
+                        die("Could not open kprobe_events file: %s",
+                            strerror(errno));
+        }
+        return ret;
+}
+
+/* Get raw string list of current kprobe_events */
+static struct strlist *get_trace_kprobe_event_rawlist(int fd)
+{
+        int ret, idx;
+        FILE *fp;
+        char buf[MAX_CMDLEN];
+        char *p;
+        struct strlist *sl;
+
+        sl = strlist__new(true, NULL);
+
+        fp = fdopen(dup(fd), "r");
+        while (!feof(fp)) {
+                p = fgets(buf, MAX_CMDLEN, fp);
+                if (!p)
+                        break;
+
+                idx = strlen(p) - 1;
+                if (p[idx] == '\n')
+                        p[idx] = '\0';
+                ret = strlist__add(sl, buf);
+                if (ret < 0)
+                        die("strlist__add failed: %s", strerror(-ret));
+        }
+        fclose(fp);
+
+        return sl;
+}
+
+/* Free and zero clear probe_point */
+static void clear_probe_point(struct probe_point *pp)
+{
+        int i;
+
+        if (pp->event)
+                free(pp->event);
+        if (pp->group)
+                free(pp->group);
+        if (pp->function)
+                free(pp->function);
+        if (pp->file)
+                free(pp->file);
+        if (pp->lazy_line)
+                free(pp->lazy_line);
+        for (i = 0; i < pp->nr_args; i++)
+                free(pp->args[i]);
+        if (pp->args)
+                free(pp->args);
+        for (i = 0; i < pp->found; i++)
+                free(pp->probes[i]);
+        memset(pp, 0, sizeof(*pp));
+}
+
+/* Show an event */
+static void show_perf_probe_event(const char *event, const char *place,
+                                  struct probe_point *pp)
+{
+        int i, ret;
+        char buf[128];
+
+        ret = e_snprintf(buf, 128, "%s:%s", pp->group, event);
+        if (ret < 0)
+                die("Failed to copy event: %s", strerror(-ret));
+        printf("  %-40s (on %s", buf, place);
+
+        if (pp->nr_args > 0) {
+                printf(" with");
+                for (i = 0; i < pp->nr_args; i++)
+                        printf(" %s", pp->args[i]);
+        }
+        printf(")\n");
+}
+
+/* List up current perf-probe events */
+void show_perf_probe_events(void)
+{
+        int fd;
+        struct probe_point pp;
+        struct strlist *rawlist;
+        struct str_node *ent;
+
+        setup_pager();
+        memset(&pp, 0, sizeof(pp));
+
+        fd = open_kprobe_events(O_RDONLY, 0);
+        rawlist = get_trace_kprobe_event_rawlist(fd);
+        close(fd);
+
+        strlist__for_each(ent, rawlist) {
+                parse_trace_kprobe_event(ent->s, &pp);
+                /* Synthesize only event probe point */
+                synthesize_perf_probe_point(&pp);
+                /* Show an event */
+                show_perf_probe_event(pp.event, pp.probes[0], &pp);
+                clear_probe_point(&pp);
+        }
+
+        strlist__delete(rawlist);
+}
+
+/* Get current perf-probe event names */
+static struct strlist *get_perf_event_names(int fd, bool include_group)
+{
+        char buf[128];
+        struct strlist *sl, *rawlist;
+        struct str_node *ent;
+        struct probe_point pp;
+
+        memset(&pp, 0, sizeof(pp));
+        rawlist = get_trace_kprobe_event_rawlist(fd);
+
+        sl = strlist__new(true, NULL);
+        strlist__for_each(ent, rawlist) {
+                parse_trace_kprobe_event(ent->s, &pp);
+                if (include_group) {
+                        if (e_snprintf(buf, 128, "%s:%s", pp.group,
+                                       pp.event) < 0)
+                                die("Failed to copy group:event name.");
+                        strlist__add(sl, buf);
+                } else
+                        strlist__add(sl, pp.event);
+                clear_probe_point(&pp);
+        }
+
+        strlist__delete(rawlist);
+
+        return sl;
+}
+
+static void write_trace_kprobe_event(int fd, const char *buf)
+{
+        int ret;
+
+        pr_debug("Writing event: %s\n", buf);
+        ret = write(fd, buf, strlen(buf));
+        if (ret <= 0)
+                die("Failed to write event: %s", strerror(errno));
+}
+
+static void get_new_event_name(char *buf, size_t len, const char *base,
+                               struct strlist *namelist, bool allow_suffix)
+{
+        int i, ret;
+
+        /* Try no suffix */
+        ret = e_snprintf(buf, len, "%s", base);
+        if (ret < 0)
+                die("snprintf() failed: %s", strerror(-ret));
+        if (!strlist__has_entry(namelist, buf))
+                return;
+
+        if (!allow_suffix) {
+                pr_warning("Error: event \"%s\" already exists. "
+                           "(Use -f to force duplicates.)\n", base);
+                die("Can't add new event.");
+        }
+
+        /* Try to add suffix */
+        for (i = 1; i < MAX_EVENT_INDEX; i++) {
+                ret = e_snprintf(buf, len, "%s_%d", base, i);
+                if (ret < 0)
+                        die("snprintf() failed: %s", strerror(-ret));
+                if (!strlist__has_entry(namelist, buf))
+                        break;
+        }
+        if (i == MAX_EVENT_INDEX)
+                die("Too many events are on the same function.");
+}
+
+void add_trace_kprobe_events(struct probe_point *probes, int nr_probes,
+                             bool force_add)
+{
+        int i, j, fd;
+        struct probe_point *pp;
+        char buf[MAX_CMDLEN];
+        char event[64];
+        struct strlist *namelist;
+        bool allow_suffix;
+
+        fd = open_kprobe_events(O_RDWR, O_APPEND);
+        /* Get current event names */
+        namelist = get_perf_event_names(fd, false);
+
+        for (j = 0; j < nr_probes; j++) {
+                pp = probes + j;
+                if (!pp->event)
+                        pp->event = strdup(pp->function);
+                if (!pp->group)
+                        pp->group = strdup(PERFPROBE_GROUP);
+                DIE_IF(!pp->event || !pp->group);
+                /* If force_add is true, suffix search is allowed */
+                allow_suffix = force_add;
+                for (i = 0; i < pp->found; i++) {
+                        /* Get an unused new event name */
+                        get_new_event_name(event, 64, pp->event, namelist,
+                                           allow_suffix);
+                        snprintf(buf, MAX_CMDLEN, "%c:%s/%s %s\n",
+                                 pp->retprobe ? 'r' : 'p',
+                                 pp->group, event,
+                                 pp->probes[i]);
+                        write_trace_kprobe_event(fd, buf);
+                        printf("Added new event:\n");
+                        /* Get the first parameter (probe-point) */
+                        sscanf(pp->probes[i], "%s", buf);
+                        show_perf_probe_event(event, buf, pp);
+                        /* Add added event name to namelist */
+                        strlist__add(namelist, event);
+                        /*
+                         * Probes after the first probe which comes from same
+                         * user input are always allowed to add suffix, because
+                         * there might be several addresses corresponding to
+                         * one code line.
+                         */
+                        allow_suffix = true;
+                }
+        }
+        /* Show how to use the event. */
+        printf("\nYou can now use it on all perf tools, such as:\n\n");
+        printf("\tperf record -e %s:%s -a sleep 1\n\n", PERFPROBE_GROUP, event);
+
+        strlist__delete(namelist);
+        close(fd);
+}
+
+static void __del_trace_kprobe_event(int fd, struct str_node *ent)
+{
+        char *p;
+        char buf[128];
+
+        /* Convert from perf-probe event to trace-kprobe event */
+        if (e_snprintf(buf, 128, "-:%s", ent->s) < 0)
+                die("Failed to copy event.");
+        p = strchr(buf + 2, ':');
+        if (!p)
+                die("Internal error: %s should have ':' but not.", ent->s);
+        *p = '/';
+
+        write_trace_kprobe_event(fd, buf);
+        printf("Remove event: %s\n", ent->s);
+}
+
+static void del_trace_kprobe_event(int fd, const char *group,
+                                   const char *event, struct strlist *namelist)
+{
+        char buf[128];
+        struct str_node *ent, *n;
+        int found = 0;
+
+        if (e_snprintf(buf, 128, "%s:%s", group, event) < 0)
+                die("Failed to copy event.");
+
+        if (strpbrk(buf, "*?")) { /* Glob-exp */
+                strlist__for_each_safe(ent, n, namelist)
+                        if (strglobmatch(ent->s, buf)) {
+                                found++;
+                                __del_trace_kprobe_event(fd, ent);
+                                strlist__remove(namelist, ent);
+                        }
+        } else {
+                ent = strlist__find(namelist, buf);
+                if (ent) {
+                        found++;
+                        __del_trace_kprobe_event(fd, ent);
+                        strlist__remove(namelist, ent);
+                }
+        }
+        if (found == 0)
+                pr_info("Info: event \"%s\" does not exist, could not remove it.\n", buf);
+}
+
+void del_trace_kprobe_events(struct strlist *dellist)
+{
+        int fd;
+        const char *group, *event;
+        char *p, *str;
+        struct str_node *ent;
+        struct strlist *namelist;
+
+        fd = open_kprobe_events(O_RDWR, O_APPEND);
+        /* Get current event names */
+        namelist = get_perf_event_names(fd, true);
+
+        strlist__for_each(ent, dellist) {
+                str = strdup(ent->s);
+                if (!str)
+                        die("Failed to copy event.");
+                pr_debug("Parsing: %s\n", str);
+                p = strchr(str, ':');
+                if (p) {
+                        group = str;
+                        *p = '\0';
+                        event = p + 1;
+                } else {
+                        group = "*";
+                        event = str;
+                }
+                pr_debug("Group: %s, Event: %s\n", group, event);
+                del_trace_kprobe_event(fd, group, event, namelist);
+                free(str);
+        }
+        strlist__delete(namelist);
+        close(fd);
+}
+
+#define LINEBUF_SIZE 256
+#define NR_ADDITIONAL_LINES 2
+
+static void show_one_line(FILE *fp, unsigned int l, bool skip, bool show_num)
+{
+        char buf[LINEBUF_SIZE];
+        const char *color = PERF_COLOR_BLUE;
+
+        if (fgets(buf, LINEBUF_SIZE, fp) == NULL)
+                goto error;
+        if (!skip) {
+                if (show_num)
+                        fprintf(stdout, "%7u  %s", l, buf);
+                else
+                        color_fprintf(stdout, color, "         %s", buf);
+        }
+
+        while (strlen(buf) == LINEBUF_SIZE - 1 &&
+               buf[LINEBUF_SIZE - 2] != '\n') {
+                if (fgets(buf, LINEBUF_SIZE, fp) == NULL)
+                        goto error;
+                if (!skip) {
+                        if (show_num)
+                                fprintf(stdout, "%s", buf);
+                        else
+                                color_fprintf(stdout, color, "%s", buf);
+                }
+        }
+        return;
+error:
+        if (feof(fp))
+                die("Source file is shorter than expected.");
+        else
+                die("File read error: %s", strerror(errno));
+}
+
+void show_line_range(struct line_range *lr)
+{
+        unsigned int l = 1;
+        struct line_node *ln;
+        FILE *fp;
+
+        setup_pager();
+
+        if (lr->function)
+                fprintf(stdout, "<%s:%d>\n", lr->function,
+                        lr->start - lr->offset);
+        else
+                fprintf(stdout, "<%s:%d>\n", lr->file, lr->start);
+
+        fp = fopen(lr->path, "r");
+        if (fp == NULL)
+                die("Failed to open %s: %s", lr->path, strerror(errno));
+        /* Skip to starting line number */
+        while (l < lr->start)
+                show_one_line(fp, l++, true, false);
+
+        list_for_each_entry(ln, &lr->line_list, list) {
+                while (ln->line > l)
+                        show_one_line(fp, (l++) - lr->offset, false, false);
+                show_one_line(fp, (l++) - lr->offset, false, true);
+        }
+
+        if (lr->end == INT_MAX)
+                lr->end = l + NR_ADDITIONAL_LINES;
+        while (l < lr->end && !feof(fp))
+                show_one_line(fp, (l++) - lr->offset, false, false);
+
+        fclose(fp);
+}