/*
* Allocate new trace_probe and initialize it (including kprobes).
*/
static struct trace_probe *alloc_trace_probe(const char *group,
const char *event,
void *addr,
const char *symbol,
unsigned long offs,
int nargs, int is_return)
{
struct trace_probe *tp;
int ret = -ENOMEM;
tp = kzalloc(SIZEOF_TRACE_PROBE(nargs), GFP_KERNEL);
if (!tp)
return ERR_PTR(ret);
if (symbol) {
tp->symbol = kstrdup(symbol, GFP_KERNEL);
if (!tp->symbol)
goto error;
tp->rp.kp.symbol_name = tp->symbol;
tp->rp.kp.offset = offs;
} else
tp->rp.kp.addr = addr;
if (is_return)
tp->rp.handler = kretprobe_dispatcher;
else
tp->rp.kp.pre_handler = kprobe_dispatcher;
if (!event || !check_event_name(event)) {
ret = -EINVAL;
goto error;
}
tp->call.name = kstrdup(event, GFP_KERNEL);
if (!tp->call.name)
goto error;
if (!group || !check_event_name(group)) {
ret = -EINVAL;
goto error;
}
tp->call.system = kstrdup(group, GFP_KERNEL);
if (!tp->call.system)
goto error;
INIT_LIST_HEAD(&tp->list);
return tp;
error:
kfree(tp->call.name);
kfree(tp->symbol);
kfree(tp);
return ERR_PTR(ret);
}
/* 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);
}
