Commit 7fb312d2 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v6.0-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing fixes from Steven Rostedt:
 "Various fixes for tracing:

   - Fix a return value of traceprobe_parse_event_name()

   - Fix NULL pointer dereference from failed ftrace enabling

   - Fix NULL pointer dereference when asking for registers from eprobes

   - Make eprobes consistent with kprobes/uprobes, filters and
     histograms"

* tag 'trace-v6.0-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Have filter accept "common_cpu" to be consistent
  tracing/probes: Have kprobes and uprobes use $COMM too
  tracing/eprobes: Have event probes be consistent with kprobes and uprobes
  tracing/eprobes: Fix reading of string fields
  tracing/eprobes: Do not hardcode $comm as a string
  tracing/eprobes: Do not allow eprobes to use $stack, or % for regs
  ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead
  tracing/perf: Fix double put of trace event when init fails
  tracing: React to error return from traceprobe_parse_event_name()
parents e3f259d3 b2380577

kernel/trace/ftrace.c

+10 −0
Original line number Diff line number Diff line
@@ -2974,6 +2974,16 @@ int ftrace_startup(struct ftrace_ops *ops, int command) 


	ftrace_startup_enable(command);



	/*

	 * If ftrace is in an undefined state, we just remove ops from list

	 * to prevent the NULL pointer, instead of totally rolling it back and

	 * free trampoline, because those actions could cause further damage.

	 */

	if (unlikely(ftrace_disabled)) {

		__unregister_ftrace_function(ops);

		return -ENODEV;

	}



	ops->flags &= ~FTRACE_OPS_FL_ADDING;



	return 0;

kernel/trace/trace_eprobe.c

+86 −7
Original line number Diff line number Diff line
@@ -227,6 +227,7 @@ static int trace_eprobe_tp_arg_update(struct trace_eprobe *ep, int i) 
	struct probe_arg *parg = &ep->tp.args[i];

	struct ftrace_event_field *field;

	struct list_head *head;

	int ret = -ENOENT;



	head = trace_get_fields(ep->event);

	list_for_each_entry(field, head, link) {
@@ -236,9 +237,20 @@ static int trace_eprobe_tp_arg_update(struct trace_eprobe *ep, int i) 
			return 0;

		}

	}



	/*

	 * Argument not found on event. But allow for comm and COMM

	 * to be used to get the current->comm.

	 */

	if (strcmp(parg->code->data, "COMM") == 0 ||

	    strcmp(parg->code->data, "comm") == 0) {

		parg->code->op = FETCH_OP_COMM;

		ret = 0;

	}



	kfree(parg->code->data);

	parg->code->data = NULL;

	return -ENOENT;

	return ret;

}



static int eprobe_event_define_fields(struct trace_event_call *event_call)
@@ -311,6 +323,27 @@ static unsigned long get_event_field(struct fetch_insn *code, void *rec) 


	addr = rec + field->offset;



	if (is_string_field(field)) {

		switch (field->filter_type) {

		case FILTER_DYN_STRING:

			val = (unsigned long)(rec + (*(unsigned int *)addr & 0xffff));

			break;

		case FILTER_RDYN_STRING:

			val = (unsigned long)(addr + (*(unsigned int *)addr & 0xffff));

			break;

		case FILTER_STATIC_STRING:

			val = (unsigned long)addr;

			break;

		case FILTER_PTR_STRING:

			val = (unsigned long)(*(char *)addr);

			break;

		default:

			WARN_ON_ONCE(1);

			return 0;

		}

		return val;

	}



	switch (field->size) {

	case 1:

		if (field->is_signed)
@@ -342,16 +375,38 @@ static unsigned long get_event_field(struct fetch_insn *code, void *rec) 


static int get_eprobe_size(struct trace_probe *tp, void *rec)

{

	struct fetch_insn *code;

	struct probe_arg *arg;

	int i, len, ret = 0;



	for (i = 0; i < tp->nr_args; i++) {

		arg = tp->args + i;

		if (unlikely(arg->dynamic)) {

		if (arg->dynamic) {

			unsigned long val;



			val = get_event_field(arg->code, rec);

			len = process_fetch_insn_bottom(arg->code + 1, val, NULL, NULL);

			code = arg->code;

 retry:

			switch (code->op) {

			case FETCH_OP_TP_ARG:

				val = get_event_field(code, rec);

				break;

			case FETCH_OP_IMM:

				val = code->immediate;

				break;

			case FETCH_OP_COMM:

				val = (unsigned long)current->comm;

				break;

			case FETCH_OP_DATA:

				val = (unsigned long)code->data;

				break;

			case FETCH_NOP_SYMBOL:	/* Ignore a place holder */

				code++;

				goto retry;

			default:

				continue;

			}

			code++;

			len = process_fetch_insn_bottom(code, val, NULL, NULL);

			if (len > 0)

				ret += len;

		}
@@ -369,8 +424,28 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest, 
{

	unsigned long val;



 retry:

	switch (code->op) {

	case FETCH_OP_TP_ARG:

		val = get_event_field(code, rec);

	return process_fetch_insn_bottom(code + 1, val, dest, base);

		break;

	case FETCH_OP_IMM:

		val = code->immediate;

		break;

	case FETCH_OP_COMM:

		val = (unsigned long)current->comm;

		break;

	case FETCH_OP_DATA:

		val = (unsigned long)code->data;

		break;

	case FETCH_NOP_SYMBOL:	/* Ignore a place holder */

		code++;

		goto retry;

	default:

		return -EILSEQ;

	}

	code++;

	return process_fetch_insn_bottom(code, val, dest, base);

}

NOKPROBE_SYMBOL(process_fetch_insn)
@@ -845,6 +920,10 @@ static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[ 
			trace_probe_log_err(0, BAD_ATTACH_ARG);

	}



	/* Handle symbols "@" */

	if (!ret)

		ret = traceprobe_update_arg(&ep->tp.args[i]);



	return ret;

}
@@ -883,7 +962,7 @@ static int __trace_eprobe_create(int argc, const char *argv[]) 
	trace_probe_log_set_index(1);

	sys_event = argv[1];

	ret = traceprobe_parse_event_name(&sys_event, &sys_name, buf2, 0);

	if (!sys_event || !sys_name) {

	if (ret || !sys_event || !sys_name) {

		trace_probe_log_err(0, NO_EVENT_INFO);

		goto parse_error;

	}

kernel/trace/trace_event_perf.c

+4 −3
Original line number Diff line number Diff line
@@ -157,7 +157,7 @@ static void perf_trace_event_unreg(struct perf_event *p_event) 
	int i;



	if (--tp_event->perf_refcount > 0)

		goto out;

		return;



	tp_event->class->reg(tp_event, TRACE_REG_PERF_UNREGISTER, NULL);
@@ -176,8 +176,6 @@ static void perf_trace_event_unreg(struct perf_event *p_event) 
			perf_trace_buf[i] = NULL;

		}

	}

out:

	trace_event_put_ref(tp_event);

}



static int perf_trace_event_open(struct perf_event *p_event)
@@ -241,6 +239,7 @@ void perf_trace_destroy(struct perf_event *p_event) 
	mutex_lock(&event_mutex);

	perf_trace_event_close(p_event);

	perf_trace_event_unreg(p_event);

	trace_event_put_ref(p_event->tp_event);

	mutex_unlock(&event_mutex);

}
@@ -292,6 +291,7 @@ void perf_kprobe_destroy(struct perf_event *p_event) 
	mutex_lock(&event_mutex);

	perf_trace_event_close(p_event);

	perf_trace_event_unreg(p_event);

	trace_event_put_ref(p_event->tp_event);

	mutex_unlock(&event_mutex);



	destroy_local_trace_kprobe(p_event->tp_event);
@@ -347,6 +347,7 @@ void perf_uprobe_destroy(struct perf_event *p_event) 
	mutex_lock(&event_mutex);

	perf_trace_event_close(p_event);

	perf_trace_event_unreg(p_event);

	trace_event_put_ref(p_event->tp_event);

	mutex_unlock(&event_mutex);

	destroy_local_trace_uprobe(p_event->tp_event);

}

kernel/trace/trace_events.c

+1 −0
Original line number Diff line number Diff line
@@ -176,6 +176,7 @@ static int trace_define_generic_fields(void) 


	__generic_field(int, CPU, FILTER_CPU);

	__generic_field(int, cpu, FILTER_CPU);

	__generic_field(int, common_cpu, FILTER_CPU);

	__generic_field(char *, COMM, FILTER_COMM);

	__generic_field(char *, comm, FILTER_COMM);

kernel/trace/trace_probe.c

+18 −11
Original line number Diff line number Diff line
@@ -283,7 +283,14 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, 
	int ret = 0;

	int len;



	if (strcmp(arg, "retval") == 0) {

	if (flags & TPARG_FL_TPOINT) {

		if (code->data)

			return -EFAULT;

		code->data = kstrdup(arg, GFP_KERNEL);

		if (!code->data)

			return -ENOMEM;

		code->op = FETCH_OP_TP_ARG;

	} else if (strcmp(arg, "retval") == 0) {

		if (flags & TPARG_FL_RETURN) {

			code->op = FETCH_OP_RETVAL;

		} else {
@@ -307,7 +314,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, 
			}

		} else

			goto inval_var;

	} else if (strcmp(arg, "comm") == 0) {

	} else if (strcmp(arg, "comm") == 0 || strcmp(arg, "COMM") == 0) {

		code->op = FETCH_OP_COMM;

#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API

	} else if (((flags & TPARG_FL_MASK) ==
@@ -323,13 +330,6 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t, 
		code->op = FETCH_OP_ARG;

		code->param = (unsigned int)param - 1;

#endif

	} else if (flags & TPARG_FL_TPOINT) {

		if (code->data)

			return -EFAULT;

		code->data = kstrdup(arg, GFP_KERNEL);

		if (!code->data)

			return -ENOMEM;

		code->op = FETCH_OP_TP_ARG;

	} else

		goto inval_var;
@@ -384,6 +384,11 @@ parse_probe_arg(char *arg, const struct fetch_type *type, 
		break;



	case '%':	/* named register */

		if (flags & TPARG_FL_TPOINT) {

			/* eprobes do not handle registers */

			trace_probe_log_err(offs, BAD_VAR);

			break;

		}

		ret = regs_query_register_offset(arg + 1);

		if (ret >= 0) {

			code->op = FETCH_OP_REG;
@@ -617,9 +622,11 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, 


	/*

	 * Since $comm and immediate string can not be dereferenced,

	 * we can find those by strcmp.

	 * we can find those by strcmp. But ignore for eprobes.

	 */

	if (strcmp(arg, "$comm") == 0 || strncmp(arg, "\\\"", 2) == 0) {

	if (!(flags & TPARG_FL_TPOINT) &&

	    (strcmp(arg, "$comm") == 0 || strcmp(arg, "$COMM") == 0 ||

	     strncmp(arg, "\\\"", 2) == 0)) {

		/* The type of $comm must be "string", and not an array. */

		if (parg->count || (t && strcmp(t, "string")))

			goto out;