perf probe: Move probe event utility functions to probe-event.c

Split probe event (kprobe-events and perf probe events) utility
functions from builtin-probe.c to probe-event.c.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jim Keniston <jkenisto@us.ibm.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Frank Ch. Eigler <fche@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Baron <jbaron@redhat.com>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20091201001958.10235.90243.stgit@harusame>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 273 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..7335a3b5e494
--- /dev/null
+++ b/tools/perf/util/probe-event.c
@@ -0,0 +1,273 @@
+/*
+ * 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>
+
+#undef _GNU_SOURCE
+#include "event.h"
+#include "debug.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)
+
+/* 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 SRC:LN
+         * perf probe FUNC[+OFFS|%return][@SRC]
+         */
+
+        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;
+                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 charactor"
+                                                " 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 charactor"
+                                                " 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);
+                        if (ptr)
+                                semantic_error("@SRC must be the last "
+                                               "option.");
+                        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->line && pp->offset)
+                semantic_error("Offset can't be used with line number.");
+
+        if (!pp->line && pp->file && !pp->function)
+                semantic_error("File always requires line number.");
+
+        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->retprobe)
+                semantic_error("Offset/Line can't be used with return probe.");
+
+        pr_debug("symbol:%s file:%s line:%d offset:%d, return:%d\n",
+                 pp->function, pp->file, pp->line, pp->offset, pp->retprobe);
+}
+
+/* Parse perf-probe event definition */
+int parse_perf_probe_event(const char *str, struct probe_point *pp)
+{
+        char *argv[MAX_PROBE_ARGS + 1]; /* probe + args */
+        int argc, i, need_dwarf = 0;
+
+        /* Separate arguments, similar to argv_split */
+        argc = 0;
+        do {
+                /* Skip separators */
+                while (isspace(*str))
+                        str++;
+
+                /* Add an argument */
+                if (*str != '\0') {
+                        const char *s = str;
+                        /* Check the limit number of arguments */
+                        if (argc == MAX_PROBE_ARGS + 1)
+                                semantic_error("Too many arguments");
+
+                        /* Skip the argument */
+                        while (!isspace(*str) && *str != '\0')
+                                str++;
+
+                        /* Duplicate the argument */
+                        argv[argc] = strndup(s, str - s);
+                        if (argv[argc] == NULL)
+                                die("strndup");
+                        pr_debug("argv[%d]=%s\n", argc, argv[argc]);
+                        argc++;
+                }
+        } while (*str != '\0');
+        if (!argc)
+                semantic_error("An empty argument.");
+
+        /* Parse probe point */
+        parse_perf_probe_probepoint(argv[0], pp);
+        free(argv[0]);
+        if (pp->file || pp->line)
+                need_dwarf = 1;
+
+        /* Copy arguments */
+        pp->nr_args = argc - 1;
+        if (pp->nr_args > 0) {
+                pp->args = (char **)malloc(sizeof(char *) * pp->nr_args);
+                if (!pp->args)
+                        die("malloc");
+                memcpy(pp->args, &argv[1], sizeof(char *) * pp->nr_args);
+        }
+
+        /* Ensure return probe has no C argument */
+        for (i = 0; i < pp->nr_args; i++)
+                if (is_c_varname(pp->args[i])) {
+                        if (pp->retprobe)
+                                semantic_error("You can't specify local"
+                                                " variable for kretprobe");
+                        need_dwarf = 1;
+                }
+
+        return need_dwarf;
+}
+
+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 = snprintf(buf, MAX_CMDLEN, "%s+%d", pp->function, pp->offset);
+        if (ret <= 0 || ret >= MAX_CMDLEN)
+                goto error;
+        len = ret;
+
+        for (i = 0; i < pp->nr_args; i++) {
+                ret = snprintf(&buf[len], MAX_CMDLEN - len, " %s",
+                               pp->args[i]);
+                if (ret <= 0 || ret >= MAX_CMDLEN - len)
+                        goto error;
+                len += ret;
+        }
+        pp->found = 1;
+
+        return pp->found;
+error:
+        free(pp->probes[0]);
+        if (ret > 0)
+                ret = -E2BIG;
+
+        return ret;
+}
+
+static int write_trace_kprobe_event(int fd, const char *buf)
+{
+        int ret;
+
+        ret = write(fd, buf, strlen(buf));
+        if (ret <= 0)
+                die("Failed to create event.");
+        else
+                printf("Added new event: %s\n", buf);
+
+        return ret;
+}
+
+void add_trace_kprobe_events(struct probe_point *probes, int nr_probes)
+{
+        int i, j, fd;
+        struct probe_point *pp;
+        char buf[MAX_CMDLEN];
+
+        snprintf(buf, MAX_CMDLEN, "%s/../kprobe_events", debugfs_path);
+        fd = open(buf, O_WRONLY, O_APPEND);
+        if (fd < 0) {
+                if (errno == ENOENT)
+                        die("kprobe_events file does not exist -"
+                            " please rebuild with CONFIG_KPROBE_TRACER.");
+                else
+                        die("Could not open kprobe_events file: %s",
+                            strerror(errno));
+        }
+
+        for (j = 0; j < nr_probes; j++) {
+                pp = probes + j;
+                if (pp->found == 1) {
+                        snprintf(buf, MAX_CMDLEN, "%c:%s/%s_%x %s\n",
+                                pp->retprobe ? 'r' : 'p', PERFPROBE_GROUP,
+                                pp->function, pp->offset, pp->probes[0]);
+                        write_trace_kprobe_event(fd, buf);
+                } else
+                        for (i = 0; i < pp->found; i++) {
+                                snprintf(buf, MAX_CMDLEN, "%c:%s/%s_%x_%d %s\n",
+                                        pp->retprobe ? 'r' : 'p',
+                                        PERFPROBE_GROUP,
+                                        pp->function, pp->offset, i,
+                                        pp->probes[i]);
+                                write_trace_kprobe_event(fd, buf);
+                        }
+        }
+        close(fd);
+}