tracing: probeevent: Fix module symbol probing

index 12bdbdf772ed..63e99ee716fe 100644
@@ -104,7 +104,7 @@ probe_mem_read(void *dest, void *src, size_t size)
 {
 	void __user *vaddr = (void __force __user *)src;
 
-	return copy_from_user(dest, vaddr, size);
+	return copy_from_user(dest, vaddr, size) ? -EFAULT : 0;
 }
 /*
  * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max

index b006aaeceb92..fbf609cbeac2 100644
@@ -62,9 +62,23 @@ static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk,
 	return strncmp(mod->name, name, len) == 0 && name[len] == ':';
 }
 
-static nokprobe_inline bool trace_kprobe_is_on_module(struct trace_kprobe *tk)
+static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk)
 {
-	return !!strchr(trace_kprobe_symbol(tk), ':');
+	char *p;
+	bool ret;
+
+	if (!tk->symbol)
+		return false;
+	p = strchr(tk->symbol, ':');
+	if (!p)
+		return true;
+	*p = '\0';
+	mutex_lock(&module_mutex);
+	ret = !!find_module(tk->symbol);
+	mutex_unlock(&module_mutex);
+	*p = ':';
+
+	return ret;
 }
 
 static nokprobe_inline unsigned long trace_kprobe_nhit(struct trace_kprobe *tk)

@@ -374,19 +388,13 @@ static int __register_trace_kprobe(struct trace_kprobe *tk)
 	else
 		ret = register_kprobe(&tk->rp.kp);
 
-	if (ret == 0)
+	if (ret == 0) {
 		tk->tp.flags |= TP_FLAG_REGISTERED;
-	else {
-		if (ret == -ENOENT && trace_kprobe_is_on_module(tk)) {
-			pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
-			ret = 0;
-		} else if (ret == -EILSEQ) {
-			pr_warn("Probing address(0x%p) is not an instruction boundary.\n",
-				tk->rp.kp.addr);
-			ret = -EINVAL;
-		}
+	} else if (ret == -EILSEQ) {
+		pr_warn("Probing address(0x%p) is not an instruction boundary.\n",
+			tk->rp.kp.addr);
+		ret = -EINVAL;
 	}
-
 	return ret;
 }
 

@@ -449,6 +457,11 @@ static int register_trace_kprobe(struct trace_kprobe *tk)
 
 	/* Register k*probe */
 	ret = __register_trace_kprobe(tk);
+	if (ret == -ENOENT && !trace_kprobe_module_exist(tk)) {
+		pr_warn("This probe might be able to register after target module is loaded. Continue.\n");
+		ret = 0;
+	}
+
 	if (ret < 0)
 		unregister_kprobe_event(tk);
 	else

index fbf609cbeac2..920985fae8c0 100644
@@ -366,7 +366,7 @@ static bool within_notrace_func(struct trace_kprobe *tk)
 /* Internal register function - just handle k*probes and flags */
 static int __register_trace_kprobe(struct trace_kprobe *tk)
 {
-	int ret;
+	int i, ret;
 
 	if (trace_probe_is_registered(&tk->tp))
 		return -EINVAL;

@@ -377,6 +377,12 @@ static int __register_trace_kprobe(struct trace_kprobe *tk)
 		return -EINVAL;
 	}
 
+	for (i = 0; i < tk->tp.nr_args; i++) {
+		ret = traceprobe_update_arg(&tk->tp.args[i]);
+		if (ret)
+			return ret;
+	}
+
 	/* Set/clear disabled flag according to tp->flag */
 	if (trace_probe_is_enabled(&tk->tp))
 		tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;

@@ -925,6 +931,7 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
 {
 	unsigned long val;
 
+retry:
 	/* 1st stage: get value from context */
 	switch (code->op) {
 	case FETCH_OP_REG:

@@ -950,6 +957,9 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
 		val = regs_get_kernel_argument(regs, code->param);
 		break;
 #endif
+	case FETCH_NOP_SYMBOL:	/* Ignore a place holder */
+		code++;
+		goto retry;
 	default:
 		return -EILSEQ;
 	}

88 lines not on this page · raw message

index 613e7b823452..052adce1388e 100644
@@ -100,6 +100,7 @@ enum fetch_op {
 	// Stage 5 (loop) op
 	FETCH_OP_LP_ARRAY,	/* Array: .param = loop count */
 	FETCH_OP_END,
+	FETCH_NOP_SYMBOL,	/* Unresolved Symbol holder */
 };
 
 struct fetch_insn {

@@ -116,6 +117,7 @@ struct fetch_insn {
 			unsigned char rshift;
 		};
 		unsigned long immediate;
+		void *data;
 	};
 };
 

@@ -276,7 +278,7 @@ extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
 extern int traceprobe_conflict_field_name(const char *name,
 			       struct probe_arg *args, int narg);
 
-extern void traceprobe_update_arg(struct probe_arg *arg);
+extern int traceprobe_update_arg(struct probe_arg *arg);
 extern void traceprobe_free_probe_arg(struct probe_arg *arg);
 
 extern int traceprobe_split_symbol_offset(char *symbol, long *offset);