1 files changed, 22 insertions, 12 deletions

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 8f7a2b6d389d..a130d612e705 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -255,12 +255,18 @@ fail:
 }
 
 /* Special function : only accept unsigned long */
-static __kprobes void fetch_stack_address(struct pt_regs *regs,
-					void *dummy, void *dest)
+static __kprobes void fetch_kernel_stack_address(struct pt_regs *regs,
+						 void *dummy, void *dest)
 {
 	*(unsigned long *)dest = kernel_stack_pointer(regs);
 }
 
+static __kprobes void fetch_user_stack_address(struct pt_regs *regs,
+					       void *dummy, void *dest)
+{
+	*(unsigned long *)dest = user_stack_pointer(regs);
+}
+
 static fetch_func_t get_fetch_size_function(const struct fetch_type *type,
 					    fetch_func_t orig_fn,
 					    const struct fetch_type *ftbl)
@@ -305,7 +311,8 @@ int traceprobe_split_symbol_offset(char *symbol, unsigned long *offset)
 #define PARAM_MAX_STACK (THREAD_SIZE / sizeof(unsigned long))
 
 static int parse_probe_vars(char *arg, const struct fetch_type *t,
-			    struct fetch_param *f, bool is_return)
+			    struct fetch_param *f, bool is_return,
+			    bool is_kprobe)
 {
 	int ret = 0;
 	unsigned long param;
@@ -317,13 +324,16 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
 			ret = -EINVAL;
 	} else if (strncmp(arg, "stack", 5) == 0) {
 		if (arg[5] == '\0') {
-			if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR) == 0)
-				f->fn = fetch_stack_address;
+			if (strcmp(t->name, DEFAULT_FETCH_TYPE_STR))
+				return -EINVAL;
+
+			if (is_kprobe)
+				f->fn = fetch_kernel_stack_address;
 			else
-				ret = -EINVAL;
+				f->fn = fetch_user_stack_address;
 		} else if (isdigit(arg[5])) {
 			ret = kstrtoul(arg + 5, 10, &param);
-			if (ret || param > PARAM_MAX_STACK)
+			if (ret || (is_kprobe && param > PARAM_MAX_STACK))
 				ret = -EINVAL;
 			else {
 				f->fn = t->fetch[FETCH_MTD_stack];
@@ -350,13 +360,9 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
 	ftbl = is_kprobe ? kprobes_fetch_type_table : uprobes_fetch_type_table;
 	BUG_ON(ftbl == NULL);
 
-	/* Until uprobe_events supports only reg arguments */
-	if (!is_kprobe && arg[0] != '%')
-		return -EINVAL;
-
 	switch (arg[0]) {
 	case '$':
-		ret = parse_probe_vars(arg + 1, t, f, is_return);
+		ret = parse_probe_vars(arg + 1, t, f, is_return, is_kprobe);
 		break;
 
 	case '%':	/* named register */
@@ -377,6 +383,10 @@ static int parse_probe_arg(char *arg, const struct fetch_type *t,
 			f->fn = t->fetch[FETCH_MTD_memory];
 			f->data = (void *)param;
 		} else {
+			/* uprobes don't support symbols */
+			if (!is_kprobe)
+				return -EINVAL;
+
 			ret = traceprobe_split_symbol_offset(arg + 1, &offset);
 			if (ret)
 				break;