tracing: probeevent: Add array type support
Add array type support for probe events. This allows user to get arraied types from memory address. The array type syntax is TYPE[N] Where TYPE is one of types (u8/16/32/64,s8/16/32/64, x8/16/32/64, symbol, string) and N is a fixed value less than 64. The string array type is a bit different from other types. For other base types, <base-type>[1] is equal to <base-type> (e.g. +0(%di):x32[1] is same as +0(%di):x32.) But string[1] is not equal to string. The string type itself represents "char array", but string array type represents "char * array". So, for example, +0(%di):string[1] is equal to +0(+0(%di)):string. Link: http://lkml.kernel.org/r/152465891533.26224.6150658225601339931.stgit@devbox Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu
committed by
Steven Rostedt (VMware)
Steven Rostedt (VMware)
parent
60c2e0cebf
commit
40b53b7718
@@ -341,9 +341,9 @@ static int __parse_bitfield_probe_arg(const char *bf,
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int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
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struct probe_arg *parg, bool is_return, bool is_kprobe)
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{
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struct fetch_insn *code, *tmp = NULL;
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const char *t;
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int ret;
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struct fetch_insn *code, *scode, *tmp = NULL;
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char *t, *t2;
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int ret, len;
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if (strlen(arg) > MAX_ARGSTR_LEN) {
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pr_info("Argument is too long.: %s\n", arg);
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@@ -354,24 +354,42 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
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pr_info("Failed to allocate memory for command '%s'.\n", arg);
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return -ENOMEM;
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}
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t = strchr(parg->comm, ':');
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t = strchr(arg, ':');
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if (t) {
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arg[t - parg->comm] = '\0';
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t++;
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*t = '\0';
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t2 = strchr(++t, '[');
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if (t2) {
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*t2 = '\0';
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parg->count = simple_strtoul(t2 + 1, &t2, 0);
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if (strcmp(t2, "]") || parg->count == 0)
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return -EINVAL;
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if (parg->count > MAX_ARRAY_LEN)
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return -E2BIG;
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}
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}
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/*
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* The default type of $comm should be "string", and it can't be
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* dereferenced.
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*/
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if (!t && strcmp(arg, "$comm") == 0)
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t = "string";
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parg->type = find_fetch_type(t);
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parg->type = find_fetch_type("string");
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else
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parg->type = find_fetch_type(t);
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if (!parg->type) {
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pr_info("Unsupported type: %s\n", t);
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return -EINVAL;
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}
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parg->offset = *size;
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*size += parg->type->size;
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*size += parg->type->size * (parg->count ?: 1);
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if (parg->count) {
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len = strlen(parg->type->fmttype) + 6;
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parg->fmt = kmalloc(len, GFP_KERNEL);
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if (!parg->fmt)
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return -ENOMEM;
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snprintf(parg->fmt, len, "%s[%d]", parg->type->fmttype,
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parg->count);
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}
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code = tmp = kzalloc(sizeof(*code) * FETCH_INSN_MAX, GFP_KERNEL);
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if (!code)
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@@ -391,10 +409,20 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
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ret = -EINVAL;
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goto fail;
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}
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/* Since IMM or COMM must be the 1st insn, this is safe */
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if (code->op == FETCH_OP_IMM || code->op == FETCH_OP_COMM)
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if (code->op != FETCH_OP_DEREF || parg->count) {
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/*
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* IMM and COMM is pointing actual address, those must
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* be kept, and if parg->count != 0, this is an array
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* of string pointers instead of string address itself.
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*/
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code++;
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if (code->op != FETCH_OP_NOP) {
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ret = -E2BIG;
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goto fail;
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}
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}
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code->op = FETCH_OP_ST_STRING; /* In DEREF case, replace it */
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code->size = parg->type->size;
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parg->dynamic = true;
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} else if (code->op == FETCH_OP_DEREF) {
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code->op = FETCH_OP_ST_MEM;
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@@ -408,12 +436,29 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
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code->op = FETCH_OP_ST_RAW;
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code->size = parg->type->size;
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}
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scode = code;
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/* Modify operation */
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if (t != NULL) {
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ret = __parse_bitfield_probe_arg(t, parg->type, &code);
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if (ret)
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goto fail;
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}
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/* Loop(Array) operation */
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if (parg->count) {
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if (scode->op != FETCH_OP_ST_MEM &&
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scode->op != FETCH_OP_ST_STRING) {
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pr_info("array only accepts memory or address\n");
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ret = -EINVAL;
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goto fail;
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}
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code++;
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if (code->op != FETCH_OP_NOP) {
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ret = -E2BIG;
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goto fail;
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}
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code->op = FETCH_OP_LP_ARRAY;
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code->param = parg->count;
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}
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code++;
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code->op = FETCH_OP_END;
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@@ -452,14 +497,17 @@ void traceprobe_free_probe_arg(struct probe_arg *arg)
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kfree(arg->code);
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kfree(arg->name);
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kfree(arg->comm);
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kfree(arg->fmt);
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}
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/* When len=0, we just calculate the needed length */
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#define LEN_OR_ZERO (len ? len - pos : 0)
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static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
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bool is_return)
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{
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int i;
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struct probe_arg *parg;
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int i, j;
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int pos = 0;
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const char *fmt, *arg;
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if (!is_return) {
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@@ -470,33 +518,49 @@ static int __set_print_fmt(struct trace_probe *tp, char *buf, int len,
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arg = "REC->" FIELD_STRING_FUNC ", REC->" FIELD_STRING_RETIP;
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}
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/* When len=0, we just calculate the needed length */
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#define LEN_OR_ZERO (len ? len - pos : 0)
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pos += snprintf(buf + pos, LEN_OR_ZERO, "\"%s", fmt);
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for (i = 0; i < tp->nr_args; i++) {
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pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=%s",
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tp->args[i].name, tp->args[i].type->fmt);
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parg = tp->args + i;
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pos += snprintf(buf + pos, LEN_OR_ZERO, " %s=", parg->name);
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if (parg->count) {
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pos += snprintf(buf + pos, LEN_OR_ZERO, "{%s",
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parg->type->fmt);
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for (j = 1; j < parg->count; j++)
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pos += snprintf(buf + pos, LEN_OR_ZERO, ",%s",
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parg->type->fmt);
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pos += snprintf(buf + pos, LEN_OR_ZERO, "}");
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} else
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pos += snprintf(buf + pos, LEN_OR_ZERO, "%s",
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parg->type->fmt);
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}
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pos += snprintf(buf + pos, LEN_OR_ZERO, "\", %s", arg);
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for (i = 0; i < tp->nr_args; i++) {
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if (strcmp(tp->args[i].type->name, "string") == 0)
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parg = tp->args + i;
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if (parg->count) {
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if (strcmp(parg->type->name, "string") == 0)
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fmt = ", __get_str(%s[%d])";
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else
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fmt = ", REC->%s[%d]";
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for (j = 0; j < parg->count; j++)
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pos += snprintf(buf + pos, LEN_OR_ZERO,
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fmt, parg->name, j);
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} else {
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if (strcmp(parg->type->name, "string") == 0)
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fmt = ", __get_str(%s)";
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else
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fmt = ", REC->%s";
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pos += snprintf(buf + pos, LEN_OR_ZERO,
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", __get_str(%s)",
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tp->args[i].name);
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else
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pos += snprintf(buf + pos, LEN_OR_ZERO, ", REC->%s",
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tp->args[i].name);
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fmt, parg->name);
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}
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}
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#undef LEN_OR_ZERO
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/* return the length of print_fmt */
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return pos;
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}
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#undef LEN_OR_ZERO
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int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return)
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{
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@@ -524,11 +588,15 @@ int traceprobe_define_arg_fields(struct trace_event_call *event_call,
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/* Set argument names as fields */
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for (i = 0; i < tp->nr_args; i++) {
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struct probe_arg *parg = &tp->args[i];
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const char *fmt = parg->type->fmttype;
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int size = parg->type->size;
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ret = trace_define_field(event_call, parg->type->fmttype,
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parg->name,
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offset + parg->offset,
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parg->type->size,
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if (parg->fmt)
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fmt = parg->fmt;
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if (parg->count)
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size *= parg->count;
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ret = trace_define_field(event_call, fmt, parg->name,
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offset + parg->offset, size,
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parg->type->is_signed,
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FILTER_OTHER);
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if (ret)
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