1 files changed, 122 insertions, 53 deletions

diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c
index 8f58ee1e8858..44c22d4e7881 100644
--- a/kernel/trace/trace_probe.c
+++ b/kernel/trace/trace_probe.c
@@ -13,8 +13,8 @@
 
 #include <linux/bpf.h>
 #include <linux/fs.h>
-#include "trace_btf.h"
 
+#include "trace_btf.h"
 #include "trace_probe.h"
 
 #undef C
@@ -154,22 +154,30 @@ fail:
 }
 
 static struct trace_probe_log trace_probe_log;
+extern struct mutex dyn_event_ops_mutex;
 
-void trace_probe_log_init(const char *subsystem, int argc, const char **argv)
+const char *trace_probe_log_init(const char *subsystem, int argc, const char **argv)
 {
+	lockdep_assert_held(&dyn_event_ops_mutex);
+
 	trace_probe_log.subsystem = subsystem;
 	trace_probe_log.argc = argc;
 	trace_probe_log.argv = argv;
 	trace_probe_log.index = 0;
+	return subsystem;
 }
 
 void trace_probe_log_clear(void)
 {
+	lockdep_assert_held(&dyn_event_ops_mutex);
+
 	memset(&trace_probe_log, 0, sizeof(trace_probe_log));
 }
 
 void trace_probe_log_set_index(int index)
 {
+	lockdep_assert_held(&dyn_event_ops_mutex);
+
 	trace_probe_log.index = index;
 }
 
@@ -178,6 +186,8 @@ void __trace_probe_log_err(int offset, int err_type)
 	char *command, *p;
 	int i, len = 0, pos = 0;
 
+	lockdep_assert_held(&dyn_event_ops_mutex);
+
 	if (!trace_probe_log.argv)
 		return;
 
@@ -205,7 +215,7 @@ void __trace_probe_log_err(int offset, int err_type)
 	p = command;
 	for (i = 0; i < trace_probe_log.argc; i++) {
 		len = strlen(trace_probe_log.argv[i]);
-		strcpy(p, trace_probe_log.argv[i]);
+		memcpy(p, trace_probe_log.argv[i], len);
 		p[len] = ' ';
 		p += len + 1;
 	}
@@ -238,7 +248,25 @@ int traceprobe_split_symbol_offset(char *symbol, long *offset)
 	return 0;
 }
 
-/* @buf must has MAX_EVENT_NAME_LEN size */
+/**
+ * traceprobe_parse_event_name() - Parse a string into group and event names
+ * @pevent: A pointer to the string to be parsed.
+ * @pgroup: A pointer to the group name.
+ * @buf:    A buffer to store the parsed group name.
+ * @offset: The offset of the string in the original user command, for logging.
+ *
+ * This parses a string with the format `[GROUP/][EVENT]` or `[GROUP.][EVENT]`
+ * (either GROUP or EVENT or both must be specified).
+ * Since the parsed group name is stored in @buf, the caller must ensure @buf
+ * is at least MAX_EVENT_NAME_LEN bytes.
+ *
+ * Return: 0 on success, or -EINVAL on failure.
+ *
+ * If success, *@pevent is updated to point to the event name part of the
+ * original string, or NULL if there is no event name.
+ * Also, *@pgroup is updated to point to the parsed group which is stored
+ * in @buf, or NULL if there is no group name.
+ */
 int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
 				char *buf, int offset)
 {
@@ -489,7 +517,7 @@ static void clear_btf_context(struct traceprobe_parse_context *ctx)
 	}
 }
 
-/* Return 1 if the field separater is arrow operator ('->') */
+/* Return 1 if the field separator is arrow operator ('->') */
 static int split_next_field(char *varname, char **next_field,
 			    struct traceprobe_parse_context *ctx)
 {
@@ -648,7 +676,7 @@ static int parse_btf_arg(char *varname,
 		ret = query_btf_context(ctx);
 		if (ret < 0 || ctx->nr_params == 0) {
 			trace_probe_log_err(ctx->offset, NO_BTF_ENTRY);
-			return PTR_ERR(params);
+			return -ENOENT;
 		}
 	}
 	params = ctx->params;
@@ -770,19 +798,51 @@ static int check_prepare_btf_string_fetch(char *typename,
 
 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
 
+static void store_entry_arg_at(struct fetch_insn *code, int argnum, int offset)
+{
+	code[0].op = FETCH_OP_ARG;
+	code[0].param = argnum;
+	code[1].op = FETCH_OP_ST_EDATA;
+	code[1].offset = offset;
+}
+
+static int get_entry_arg_max_offset(struct probe_entry_arg *earg)
+{
+	int i, max_offset = 0;
+
+	/*
+	 * earg->code[] array has an operation sequence which is run in
+	 * the entry handler.
+	 * The sequence stopped by FETCH_OP_END and each data stored in
+	 * the entry data buffer by FETCH_OP_ST_EDATA. The FETCH_OP_ST_EDATA
+	 * stores the data at the data buffer + its offset, and all data are
+	 * "unsigned long" size. The offset must be increased when a data is
+	 * stored. Thus we need to find the last FETCH_OP_ST_EDATA in the
+	 * code array.
+	 */
+	for (i = 0; i < earg->size - 1 && earg->code[i].op != FETCH_OP_END; i++) {
+		if (earg->code[i].op == FETCH_OP_ST_EDATA)
+			if (earg->code[i].offset > max_offset)
+				max_offset = earg->code[i].offset;
+	}
+	return max_offset;
+}
+
+/*
+ * Add the entry code to store the 'argnum'th parameter and return the offset
+ * in the entry data buffer where the data will be stored.
+ */
 static int __store_entry_arg(struct trace_probe *tp, int argnum)
 {
 	struct probe_entry_arg *earg = tp->entry_arg;
-	bool match = false;
-	int i, offset;
+	int i, offset, last_offset = 0;
 
 	if (!earg) {
-		earg = kzalloc(sizeof(*tp->entry_arg), GFP_KERNEL);
+		earg = kzalloc_obj(*tp->entry_arg);
 		if (!earg)
 			return -ENOMEM;
 		earg->size = 2 * tp->nr_args + 1;
-		earg->code = kcalloc(earg->size, sizeof(struct fetch_insn),
-				     GFP_KERNEL);
+		earg->code = kzalloc_objs(struct fetch_insn, earg->size);
 		if (!earg->code) {
 			kfree(earg);
 			return -ENOMEM;
@@ -791,54 +851,59 @@ static int __store_entry_arg(struct trace_probe *tp, int argnum)
 		for (i = 0; i < earg->size; i++)
 			earg->code[i].op = FETCH_OP_END;
 		tp->entry_arg = earg;
+		store_entry_arg_at(earg->code, argnum, 0);
+		return 0;
 	}
 
-	offset = 0;
-	for (i = 0; i < earg->size - 1; i++) {
-		switch (earg->code[i].op) {
-		case FETCH_OP_END:
-			earg->code[i].op = FETCH_OP_ARG;
-			earg->code[i].param = argnum;
-			earg->code[i + 1].op = FETCH_OP_ST_EDATA;
-			earg->code[i + 1].offset = offset;
-			return offset;
-		case FETCH_OP_ARG:
-			match = (earg->code[i].param == argnum);
-			break;
-		case FETCH_OP_ST_EDATA:
-			offset = earg->code[i].offset;
-			if (match)
-				return offset;
-			offset += sizeof(unsigned long);
-			break;
-		default:
-			break;
-		}
+	/*
+	 * NOTE: if anyone change the following rule, please rewrite this.
+	 * The entry code array is filled with the pair of
+	 *
+	 * [FETCH_OP_ARG(argnum)]
+	 * [FETCH_OP_ST_EDATA(offset of entry data buffer)]
+	 *
+	 * and the rest of entries are filled with [FETCH_OP_END].
+	 * The offset should be incremented, thus the last pair should
+	 * have the largest offset.
+	 */
+
+	/* Search the offset for the sprcified argnum. */
+	for (i = 0; i < earg->size - 1 && earg->code[i].op != FETCH_OP_END; i += 2) {
+		if (WARN_ON_ONCE(earg->code[i].op != FETCH_OP_ARG))
+			return -EINVAL;
+
+		if (earg->code[i].param != argnum)
+			continue;
+
+		if (WARN_ON_ONCE(earg->code[i + 1].op != FETCH_OP_ST_EDATA))
+			return -EINVAL;
+
+		return earg->code[i + 1].offset;
+	}
+	/* Not found, append new entry if possible. */
+	if (i >= earg->size - 1)
+		return -ENOSPC;
+
+	/* The last entry must have the largest offset. */
+	if (i != 0) {
+		if (WARN_ON_ONCE(earg->code[i - 1].op != FETCH_OP_ST_EDATA))
+			return -EINVAL;
+		last_offset = earg->code[i - 1].offset;
 	}
-	return -ENOSPC;
+
+	offset = last_offset + sizeof(unsigned long);
+	store_entry_arg_at(&earg->code[i], argnum, offset);
+	return offset;
 }
 
 int traceprobe_get_entry_data_size(struct trace_probe *tp)
 {
 	struct probe_entry_arg *earg = tp->entry_arg;
-	int i, size = 0;
 
 	if (!earg)
 		return 0;
 
-	for (i = 0; i < earg->size; i++) {
-		switch (earg->code[i].op) {
-		case FETCH_OP_END:
-			goto out;
-		case FETCH_OP_ST_EDATA:
-			size = earg->code[i].offset + sizeof(unsigned long);
-			break;
-		default:
-			break;
-		}
-	}
-out:
-	return size;
+	return get_entry_arg_max_offset(earg) + sizeof(unsigned long);
 }
 
 void store_trace_entry_data(void *edata, struct trace_probe *tp, struct pt_regs *regs)
@@ -897,8 +962,6 @@ static int parse_probe_vars(char *orig_arg, const struct fetch_type *t,
 			code->op = FETCH_OP_COMM;
 			return 0;
 		}
-		/* backward compatibility */
-		ctx->offset = 0;
 		goto inval;
 	}
 
@@ -1003,7 +1066,7 @@ static int __parse_imm_string(char *str, char **pbuf, int offs)
 {
 	size_t len = strlen(str);
 
-	if (str[len - 1] != '"') {
+	if (!len || str[len - 1] != '"') {
 		trace_probe_log_err(offs + len, IMMSTR_NO_CLOSE);
 		return -EINVAL;
 	}
@@ -1433,7 +1496,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
 	if (IS_ERR(type))
 		return PTR_ERR(type);
 
-	code = tmp = kcalloc(FETCH_INSN_MAX, sizeof(*code), GFP_KERNEL);
+	code = tmp = kzalloc_objs(*code, FETCH_INSN_MAX);
 	if (!code)
 		return -ENOMEM;
 	code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
@@ -1458,6 +1521,12 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
 	parg->offset = *size;
 	*size += parg->type->size * (parg->count ?: 1);
 
+	if (*size > MAX_PROBE_EVENT_SIZE) {
+		ret = -E2BIG;
+		trace_probe_log_err(ctx->offset, EVENT_TOO_BIG);
+		goto fail;
+	}
+
 	if (parg->count) {
 		len = strlen(parg->type->fmttype) + 6;
 		parg->fmt = kmalloc(len, GFP_KERNEL);
@@ -1477,7 +1546,7 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size,
 		if (code->op == FETCH_OP_END)
 			break;
 	/* Shrink down the code buffer */
-	parg->code = kcalloc(code - tmp + 1, sizeof(*code), GFP_KERNEL);
+	parg->code = kzalloc_objs(*code, code - tmp + 1);
 	if (!parg->code)
 		ret = -ENOMEM;
 	else
@@ -2083,7 +2152,7 @@ int trace_probe_add_file(struct trace_probe *tp, struct trace_event_file *file)
 {
 	struct event_file_link *link;
 
-	link = kmalloc(sizeof(*link), GFP_KERNEL);
+	link = kmalloc_obj(*link);
 	if (!link)
 		return -ENOMEM;