tracing: probeevent: Improve fetcharg features

index 492700c5fb4d..7d9df336805e 100644
@@ -1058,8 +1058,6 @@ print_kprobe_event(struct trace_iterator *iter, int flags,
 	struct kprobe_trace_entry_head *field;
 	struct trace_seq *s = &iter->seq;
 	struct trace_probe *tp;
-	u8 *data;
-	int i;
 
 	field = (struct kprobe_trace_entry_head *)iter->ent;
 	tp = container_of(event, struct trace_probe, call.event);

@@ -1071,11 +1069,9 @@ print_kprobe_event(struct trace_iterator *iter, int flags,
 
 	trace_seq_putc(s, ')');
 
-	data = (u8 *)&field[1];
-	for (i = 0; i < tp->nr_args; i++)
-		if (!tp->args[i].type->print(s, tp->args[i].name,
-					     data + tp->args[i].offset, field))
-			goto out;
+	if (print_probe_args(s, tp->args, tp->nr_args,
+			     (u8 *)&field[1], field) < 0)
+		goto out;
 
 	trace_seq_putc(s, '\n');
  out:

@@ -1089,8 +1085,6 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,
 	struct kretprobe_trace_entry_head *field;
 	struct trace_seq *s = &iter->seq;
 	struct trace_probe *tp;
-	u8 *data;
-	int i;
 
 	field = (struct kretprobe_trace_entry_head *)iter->ent;
 	tp = container_of(event, struct trace_probe, call.event);

@@ -1107,11 +1101,9 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,
 
 	trace_seq_putc(s, ')');
 
-	data = (u8 *)&field[1];
-	for (i = 0; i < tp->nr_args; i++)
-		if (!tp->args[i].type->print(s, tp->args[i].name,
-					     data + tp->args[i].offset, field))
-			goto out;
+	if (print_probe_args(s, tp->args, tp->nr_args,
+			     (u8 *)&field[1], field) < 0)
+		goto out;
 
 	trace_seq_putc(s, '\n');
 

index d59357308677..4a6021fd14df 100644
@@ -38,10 +38,9 @@ const char *reserved_field_names[] = {
 
 /* Printing  in basic type function template */
 #define DEFINE_BASIC_PRINT_TYPE_FUNC(tname, type, fmt)			\
-int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, const char *name,	\
-				void *data, void *ent)			\
+int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
 {									\
-	trace_seq_printf(s, " %s=" fmt, name, *(type *)data);		\
+	trace_seq_printf(s, fmt, *(type *)data);			\
 	return !trace_seq_has_overflowed(s);				\
 }									\
 const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;				\

@@ -61,15 +60,14 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
 
 /* Print type function for string type */
-int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, const char *name,
-				 void *data, void *ent)
+int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
 {
 	int len = *(u32 *)data >> 16;
 
 	if (!len)
-		trace_seq_printf(s, " %s=(fault)", name);
+		trace_seq_puts(s, "(fault)");
 	else
-		trace_seq_printf(s, " %s=\"%s\"", name,
+		trace_seq_printf(s, "\"%s\"",
 				 (const char *)get_loc_data(data, ent));
 	return !trace_seq_has_overflowed(s);
 }

index fb66e3eaa192..cbefd29a0131 100644
@@ -94,7 +94,7 @@ static nokprobe_inline void *get_loc_data(u32 *dl, void *ent)
 /* Data fetch function type */
 typedef	void (*fetch_func_t)(struct pt_regs *, void *, void *);
 /* Printing function type */
-typedef int (*print_type_func_t)(struct trace_seq *, const char *, void *, void *);
+typedef int (*print_type_func_t)(struct trace_seq *, void *, void *);
 
 /* Fetch types */
 enum {

@@ -136,8 +136,7 @@ typedef u32 string_size;
 
 /* Printing  in basic type function template */
 #define DECLARE_BASIC_PRINT_TYPE_FUNC(type)				\
-int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, const char *name,	\
-				void *data, void *ent);			\
+int PRINT_TYPE_FUNC_NAME(type)(struct trace_seq *s, void *data, void *ent);\
 extern const char PRINT_TYPE_FMT_NAME(type)[]
 
 DECLARE_BASIC_PRINT_TYPE_FUNC(u8);

@@ -403,4 +402,18 @@ store_trace_args(int ent_size, struct trace_probe *tp, struct pt_regs *regs,
 	}
 }
 
+static inline int
+print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
+		 u8 *data, void *field)
+{
+	int i;
+
+	for (i = 0; i < nr_args; i++) {
+		trace_seq_printf(s, " %s=", args[i].name);
+		if (!args[i].type->print(s, data + args[i].offset, field))
+			return -ENOMEM;
+	}
+	return 0;
+}
+
 extern int set_print_fmt(struct trace_probe *tp, bool is_return);

index 40592e7b3568..3d7e039d5628 100644
@@ -864,7 +864,6 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
 	struct trace_seq *s = &iter->seq;
 	struct trace_uprobe *tu;
 	u8 *data;
-	int i;
 
 	entry = (struct uprobe_trace_entry_head *)iter->ent;
 	tu = container_of(event, struct trace_uprobe, tp.call.event);

@@ -881,12 +880,8 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
 		data = DATAOF_TRACE_ENTRY(entry, false);
 	}
 
-	for (i = 0; i < tu->tp.nr_args; i++) {
-		struct probe_arg *parg = &tu->tp.args[i];
-
-		if (!parg->type->print(s, parg->name, data + parg->offset, entry))
-			goto out;
-	}
+	if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
+		goto out;
 
 	trace_seq_putc(s, '\n');
 

index 7d9df336805e..1fe29b7f4c32 100644
@@ -1114,49 +1114,25 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,
 
 static int kprobe_event_define_fields(struct trace_event_call *event_call)
 {
-	int ret, i;
+	int ret;
 	struct kprobe_trace_entry_head field;
 	struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
 
 	DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);
-	/* Set argument names as fields */
-	for (i = 0; i < tk->tp.nr_args; i++) {
-		struct probe_arg *parg = &tk->tp.args[i];
 
-		ret = trace_define_field(event_call, parg->type->fmttype,
-					 parg->name,
-					 sizeof(field) + parg->offset,
-					 parg->type->size,
-					 parg->type->is_signed,
-					 FILTER_OTHER);
-		if (ret)
-			return ret;
-	}
-	return 0;
+	return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp);
 }
 
 static int kretprobe_event_define_fields(struct trace_event_call *event_call)
 {
-	int ret, i;
+	int ret;
 	struct kretprobe_trace_entry_head field;
 	struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
 
 	DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
 	DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);
-	/* Set argument names as fields */
-	for (i = 0; i < tk->tp.nr_args; i++) {
-		struct probe_arg *parg = &tk->tp.args[i];
 
-		ret = trace_define_field(event_call, parg->type->fmttype,
-					 parg->name,
-					 sizeof(field) + parg->offset,
-					 parg->type->size,
-					 parg->type->is_signed,
-					 FILTER_OTHER);
-		if (ret)
-			return ret;
-	}
-	return 0;
+	return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp);
 }
 
 #ifdef CONFIG_PERF_EVENTS

index 4a6021fd14df..157cfdfa8430 100644
@@ -682,3 +682,24 @@ int set_print_fmt(struct trace_probe *tp, bool is_return)
 
 	return 0;
 }
+
+int traceprobe_define_arg_fields(struct trace_event_call *event_call,
+				 size_t offset, struct trace_probe *tp)
+{
+	int ret, i;
+
+	/* Set argument names as fields */
+	for (i = 0; i < tp->nr_args; i++) {
+		struct probe_arg *parg = &tp->args[i];
+
+		ret = trace_define_field(event_call, parg->type->fmttype,
+					 parg->name,
+					 offset + parg->offset,
+					 parg->type->size,
+					 parg->type->is_signed,
+					 FILTER_OTHER);
+		if (ret)
+			return ret;
+	}
+	return 0;
+}

index cbefd29a0131..a1490e279658 100644
@@ -417,3 +417,5 @@ print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
 }
 
 extern int set_print_fmt(struct trace_probe *tp, bool is_return);
+extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
+					size_t offset, struct trace_probe *tp);

index 3d7e039d5628..968bd403d68c 100644
@@ -982,7 +982,7 @@ probe_event_disable(struct trace_uprobe *tu, struct trace_event_file *file)
 
 static int uprobe_event_define_fields(struct trace_event_call *event_call)
 {
-	int ret, i, size;
+	int ret, size;
 	struct uprobe_trace_entry_head field;
 	struct trace_uprobe *tu = event_call->data;
 

@@ -994,19 +994,8 @@ static int uprobe_event_define_fields(struct trace_event_call *event_call)
 		DEFINE_FIELD(unsigned long, vaddr[0], FIELD_STRING_IP, 0);
 		size = SIZEOF_TRACE_ENTRY(false);
 	}
-	/* Set argument names as fields */
-	for (i = 0; i < tu->tp.nr_args; i++) {
-		struct probe_arg *parg = &tu->tp.args[i];
-
-		ret = trace_define_field(event_call, parg->type->fmttype,
-					 parg->name, size + parg->offset,
-					 parg->type->size, parg->type->is_signed,
-					 FILTER_OTHER);
 
-		if (ret)
-			return ret;
-	}
-	return 0;
+	return traceprobe_define_arg_fields(event_call, size, &tu->tp);
 }
 
 #ifdef CONFIG_PERF_EVENTS

index 157cfdfa8430..be98a58416a9 100644
@@ -43,8 +43,7 @@ int PRINT_TYPE_FUNC_NAME(tname)(struct trace_seq *s, void *data, void *ent)\
 	trace_seq_printf(s, fmt, *(type *)data);			\
 	return !trace_seq_has_overflowed(s);				\
 }									\
-const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;				\
-NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(tname));
+const char PRINT_TYPE_FMT_NAME(tname)[] = fmt;
 
 DEFINE_BASIC_PRINT_TYPE_FUNC(u8,  u8,  "%u")
 DEFINE_BASIC_PRINT_TYPE_FUNC(u16, u16, "%u")

@@ -71,7 +70,6 @@ int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
 				 (const char *)get_loc_data(data, ent));
 	return !trace_seq_has_overflowed(s);
 }
-NOKPROBE_SYMBOL(PRINT_TYPE_FUNC_NAME(string));
 
 const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";
 

index 1fe29b7f4c32..1d0554c6bb34 100644
@@ -97,184 +97,6 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs);
 static int kretprobe_dispatcher(struct kretprobe_instance *ri,
 				struct pt_regs *regs);
 
-/* Memory fetching by symbol */
-struct symbol_cache {
-	char		*symbol;
-	long		offset;
-	unsigned long	addr;
-};
-
-unsigned long update_symbol_cache(struct symbol_cache *sc)
-{
-	sc->addr = (unsigned long)kallsyms_lookup_name(sc->symbol);
-
-	if (sc->addr)
-		sc->addr += sc->offset;
-
-	return sc->addr;
-}
-
-void free_symbol_cache(struct symbol_cache *sc)
-{
-	kfree(sc->symbol);
-	kfree(sc);
-}
-
-struct symbol_cache *alloc_symbol_cache(const char *sym, long offset)
-{
-	struct symbol_cache *sc;
-
-	if (!sym || strlen(sym) == 0)
-		return NULL;
-
-	sc = kzalloc(sizeof(struct symbol_cache), GFP_KERNEL);
-	if (!sc)
-		return NULL;
-
-	sc->symbol = kstrdup(sym, GFP_KERNEL);
-	if (!sc->symbol) {
-		kfree(sc);
-		return NULL;
-	}
-	sc->offset = offset;
-	update_symbol_cache(sc);
-
-	return sc;
-}
-
-/*
- * Kprobes-specific fetch functions
- */
-#define DEFINE_FETCH_stack(type)					\
-static void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,		\
-					  void *offset, void *dest)	\
-{									\
-	*(type *)dest = (type)regs_get_kernel_stack_nth(regs,		\
-				(unsigned int)((unsigned long)offset));	\
-}									\
-NOKPROBE_SYMBOL(FETCH_FUNC_NAME(stack, type));
-
-DEFINE_BASIC_FETCH_FUNCS(stack)
-/* No string on the stack entry */
-#define fetch_stack_string	NULL
-#define fetch_stack_string_size	NULL
-
-#define DEFINE_FETCH_memory(type)					\
-static void FETCH_FUNC_NAME(memory, type)(struct pt_regs *regs,		\
-					  void *addr, void *dest)	\
-{									\
-	type retval;							\
-	if (probe_kernel_address(addr, retval))				\
-		*(type *)dest = 0;					\
-	else								\
-		*(type *)dest = retval;					\
-}									\
-NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, type));
-
-DEFINE_BASIC_FETCH_FUNCS(memory)
-/*
- * Fetch a null-terminated string. Caller MUST set *(u32 *)dest with max
- * length and relative data location.
- */
-static void FETCH_FUNC_NAME(memory, string)(struct pt_regs *regs,
-					    void *addr, void *dest)
-{
-	int maxlen = get_rloc_len(*(u32 *)dest);
-	u8 *dst = get_rloc_data(dest);
-	long ret;
-
-	if (!maxlen)
-		return;
-
-	/*
-	 * Try to get string again, since the string can be changed while
-	 * probing.
-	 */
-	ret = strncpy_from_unsafe(dst, addr, maxlen);
-
-	if (ret < 0) {	/* Failed to fetch string */
-		dst[0] = '\0';
-		*(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
-	} else {
-		*(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
-	}
-}
-NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string));
-
-/* Return the length of string -- including null terminal byte */
-static void FETCH_FUNC_NAME(memory, string_size)(struct pt_regs *regs,
-						 void *addr, void *dest)
-{
-	mm_segment_t old_fs;
-	int ret, len = 0;
-	u8 c;
-
-	old_fs = get_fs();
-	set_fs(KERNEL_DS);
-	pagefault_disable();
-
-	do {
-		ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
-		len++;
-	} while (c && ret == 0 && len < MAX_STRING_SIZE);
-
-	pagefault_enable();
-	set_fs(old_fs);
-
-	if (ret < 0)	/* Failed to check the length */
-		*(u32 *)dest = 0;
-	else
-		*(u32 *)dest = len;
-}
-NOKPROBE_SYMBOL(FETCH_FUNC_NAME(memory, string_size));
-
-#define DEFINE_FETCH_symbol(type)					\
-void FETCH_FUNC_NAME(symbol, type)(struct pt_regs *regs, void *data, void *dest)\
-{									\
-	struct symbol_cache *sc = data;					\
-	if (sc->addr)							\
-		fetch_memory_##type(regs, (void *)sc->addr, dest);	\
-	else								\
-		*(type *)dest = 0;					\
-}									\
-NOKPROBE_SYMBOL(FETCH_FUNC_NAME(symbol, type));
-
-DEFINE_BASIC_FETCH_FUNCS(symbol)
-DEFINE_FETCH_symbol(string)
-DEFINE_FETCH_symbol(string_size)
-
-/* kprobes don't support file_offset fetch methods */
-#define fetch_file_offset_u8		NULL
-#define fetch_file_offset_u16		NULL
-#define fetch_file_offset_u32		NULL
-#define fetch_file_offset_u64		NULL
-#define fetch_file_offset_string	NULL
-#define fetch_file_offset_string_size	NULL
-
-/* Fetch type information table */
-static const struct fetch_type kprobes_fetch_type_table[] = {
-	/* Special types */
-	[FETCH_TYPE_STRING] = __ASSIGN_FETCH_TYPE("string", string, string,
-					sizeof(u32), 1, "__data_loc char[]"),
-	[FETCH_TYPE_STRSIZE] = __ASSIGN_FETCH_TYPE("string_size", u32,
-					string_size, sizeof(u32), 0, "u32"),
-	/* Basic types */
-	ASSIGN_FETCH_TYPE(u8,  u8,  0),
-	ASSIGN_FETCH_TYPE(u16, u16, 0),
-	ASSIGN_FETCH_TYPE(u32, u32, 0),
-	ASSIGN_FETCH_TYPE(u64, u64, 0),
-	ASSIGN_FETCH_TYPE(s8,  u8,  1),
-	ASSIGN_FETCH_TYPE(s16, u16, 1),
-	ASSIGN_FETCH_TYPE(s32, u32, 1),
-	ASSIGN_FETCH_TYPE(s64, u64, 1),
-	ASSIGN_FETCH_TYPE_ALIAS(x8,  u8,  u8,  0),
-	ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
-	ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
-	ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
-
-	ASSIGN_FETCH_TYPE_END
-};
-
 /*
  * Allocate new trace_probe and initialize it (including kprobes).
  */

@@ -458,14 +280,11 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
 /* Internal register function - just handle k*probes and flags */
 static int __register_trace_kprobe(struct trace_kprobe *tk)
 {
-	int i, ret;
+	int ret;
 
 	if (trace_probe_is_registered(&tk->tp))
 		return -EINVAL;
 
-	for (i = 0; i < tk->tp.nr_args; i++)
-		traceprobe_update_arg(&tk->tp.args[i]);
-
 	/* Set/clear disabled flag according to tp->flag */
 	if (trace_probe_is_enabled(&tk->tp))
 		tk->rp.kp.flags &= ~KPROBE_FLAG_DISABLED;

@@ -798,8 +617,7 @@ static int create_trace_kprobe(int argc, char **argv)
 
 		/* Parse fetch argument */
 		ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,
-						is_return, true,
-						kprobes_fetch_type_table);
+						 is_return, true);
 		if (ret) {
 			pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
 			goto error;

@@ -953,6 +771,133 @@ static const struct file_operations kprobe_profile_ops = {
 	.release        = seq_release,
 };
 
+/* Kprobe specific fetch functions */
+
+/* Return the length of string -- including null terminal byte */
+static nokprobe_inline void
+fetch_store_strlen(unsigned long addr, void *dest)
+{
+	mm_segment_t old_fs;
+	int ret, len = 0;
+	u8 c;
+
+	old_fs = get_fs();
+	set_fs(KERNEL_DS);
+	pagefault_disable();
+
+	do {
+		ret = __copy_from_user_inatomic(&c, (u8 *)addr + len, 1);
+		len++;
+	} while (c && ret == 0 && len < MAX_STRING_SIZE);
+
+	pagefault_enable();
+	set_fs(old_fs);
+
+	if (ret < 0)	/* Failed to check the length */
+		*(u32 *)dest = 0;
+	else
+		*(u32 *)dest = len;
+}
+
+/*
+ * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
+ * length and relative data location.
+ */
+static nokprobe_inline void
+fetch_store_string(unsigned long addr, void *dest)
+{
+	int maxlen = get_rloc_len(*(u32 *)dest);
+	u8 *dst = get_rloc_data(dest);
+	long ret;
+
+	if (!maxlen)
+		return;
+
+	/*
+	 * Try to get string again, since the string can be changed while
+	 * probing.
+	 */
+	ret = strncpy_from_unsafe(dst, (void *)addr, maxlen);
+
+	if (ret < 0) {	/* Failed to fetch string */
+		dst[0] = '\0';
+		*(u32 *)dest = make_data_rloc(0, get_rloc_offs(*(u32 *)dest));
+	} else {
+		*(u32 *)dest = make_data_rloc(ret, get_rloc_offs(*(u32 *)dest));
+	}
+}
+
+/* Note that we don't verify it, since the code does not come from user space */
+static int
+process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
+		   bool pre)
+{
+	unsigned long val;
+	int ret;
+
+	/* 1st stage: get value from context */
+	switch (code->op) {
+	case FETCH_OP_REG:
+		val = regs_get_register(regs, code->param);
+		break;
+	case FETCH_OP_STACK:
+		val = regs_get_kernel_stack_nth(regs, code->param);
+		break;
+	case FETCH_OP_STACKP:
+		val = kernel_stack_pointer(regs);
+		break;
+	case FETCH_OP_RETVAL:
+		val = regs_return_value(regs);
+		break;
+	case FETCH_OP_IMM:
+		val = code->immediate;
+		break;
+	case FETCH_OP_COMM:
+		val = (unsigned long)current->comm;
+		break;
+	default:
+		return -EILSEQ;
+	}
+	code++;
+
+	/* 2nd stage: dereference memory if needed */
+	while (code->op == FETCH_OP_DEREF) {
+		ret = probe_kernel_read(&val, (void *)val + code->offset,
+					sizeof(val));
+		if (ret)
+			return ret;
+		code++;
+	}
+
+	/* 3rd stage: store value to buffer */
+	switch (code->op) {
+	case FETCH_OP_ST_RAW:
+		fetch_store_raw(val, code, dest);
+		break;
+	case FETCH_OP_ST_MEM:
+		probe_kernel_read(dest, (void *)val + code->offset, code->size);
+		break;
+	case FETCH_OP_ST_STRING:
+		if (pre)
+			fetch_store_strlen(val + code->offset, dest);
+		else
+			fetch_store_string(val + code->offset, dest);
+		break;
+	default:
+		return -EILSEQ;
+	}
+	code++;
+
+	/* 4th stage: modify stored value if needed */
+	if (code->op == FETCH_OP_MOD_BF) {
+		fetch_apply_bitfield(code, dest);
+		code++;
+	}
+
+	return code->op == FETCH_OP_END ? 0 : -EILSEQ;
+}
+NOKPROBE_SYMBOL(process_fetch_insn)
+
 /* Kprobe handler */
 static nokprobe_inline void
 __kprobe_trace_func(struct trace_kprobe *tk, struct pt_regs *regs,

613 lines not on this page · raw message

342 lines not on this page · raw message

187 lines not on this page · raw message

index 52b4931864d6..f56dfadd29d5 100644
@@ -58,6 +58,13 @@ DEFINE_BASIC_PRINT_TYPE_FUNC(x16, u16, "0x%x")
 DEFINE_BASIC_PRINT_TYPE_FUNC(x32, u32, "0x%x")
 DEFINE_BASIC_PRINT_TYPE_FUNC(x64, u64, "0x%Lx")
 
+int PRINT_TYPE_FUNC_NAME(symbol)(struct trace_seq *s, void *data, void *ent)
+{
+	trace_seq_printf(s, "%pS", (void *)*(unsigned long *)data);
+	return !trace_seq_has_overflowed(s);
+}
+const char PRINT_TYPE_FMT_NAME(symbol)[] = "%pS";
+
 /* Print type function for string type */
 int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, void *data, void *ent)
 {

@@ -103,6 +110,7 @@ static const struct fetch_type probe_fetch_types[] = {
 	ASSIGN_FETCH_TYPE_ALIAS(x16, u16, u16, 0),
 	ASSIGN_FETCH_TYPE_ALIAS(x32, u32, u32, 0),
 	ASSIGN_FETCH_TYPE_ALIAS(x64, u64, u64, 0),
+	ASSIGN_FETCH_TYPE_ALIAS(symbol, ADDR_FETCH_TYPE, ADDR_FETCH_TYPE, 0),
 
 	ASSIGN_FETCH_TYPE_END
 };

index b22792a6f889..2234586b9942 100644
@@ -171,6 +171,7 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(x32);
 DECLARE_BASIC_PRINT_TYPE_FUNC(x64);
 
 DECLARE_BASIC_PRINT_TYPE_FUNC(string);
+DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);
 
 /* Default (unsigned long) fetch type */
 #define __DEFAULT_FETCH_TYPE(t) x##t

@@ -178,6 +179,10 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(string);
 #define DEFAULT_FETCH_TYPE _DEFAULT_FETCH_TYPE(BITS_PER_LONG)
 #define DEFAULT_FETCH_TYPE_STR __stringify(DEFAULT_FETCH_TYPE)
 
+#define __ADDR_FETCH_TYPE(t) u##t
+#define _ADDR_FETCH_TYPE(t) __ADDR_FETCH_TYPE(t)
+#define ADDR_FETCH_TYPE _ADDR_FETCH_TYPE(BITS_PER_LONG)
+
 #define __ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype)	\
 	{.name = _name,				\
 	 .size = _size,					\

@@ -186,13 +191,14 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(string);
 	 .fmt = PRINT_TYPE_FMT_NAME(ptype),		\
 	 .fmttype = _fmttype,				\
 	}
-
+#define _ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, _fmttype)	\
+	__ASSIGN_FETCH_TYPE(_name, ptype, ftype, _size, sign, #_fmttype)
 #define ASSIGN_FETCH_TYPE(ptype, ftype, sign)			\
-	__ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #ptype)
+	_ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, ptype)
 
 /* If ptype is an alias of atype, use this macro (show atype in format) */
 #define ASSIGN_FETCH_TYPE_ALIAS(ptype, atype, ftype, sign)		\
-	__ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, #atype)
+	_ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
 
 #define ASSIGN_FETCH_TYPE_END {}
 

index 14131dd06b29..f0688ec22b15 100644
@@ -251,6 +251,44 @@ static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
 		return 0;
 }
 
+/**
+ * regs_get_kernel_argument() - get Nth function argument in kernel
+ * @regs:	pt_regs of that context
+ * @n:		function argument number (start from 0)
+ *
+ * regs_get_argument() returns @n th argument of the function call.
+ * Note that this chooses most probably assignment, in some case
+ * it can be incorrect.
+ * This is expected to be called from kprobes or ftrace with regs
+ * where the top of stack is the return address.
+ */
+static inline unsigned long regs_get_kernel_argument(struct pt_regs *regs,
+						     unsigned int n)
+{
+	const static unsigned int argument_offs[] = {
+#ifdef __i386__
+		offsetof(struct pt_regs, ax),
+		offsetof(struct pt_regs, cx),
+		offsetof(struct pt_regs, dx),
+#define NR_REG_ARGUMENTS 3
+#else
+		offsetof(struct pt_regs, di),
+		offsetof(struct pt_regs, si),
+		offsetof(struct pt_regs, dx),
+		offsetof(struct pt_regs, cx),
+		offsetof(struct pt_regs, r8),
+		offsetof(struct pt_regs, r9),
+#define NR_REG_ARGUMENTS 6
+#endif
+	};
+
+	if (n >= NR_REG_ARGUMENTS) {
+		n -= NR_REG_ARGUMENTS - 1;
+		return regs_get_kernel_stack_nth(regs, n);
+	} else
+		return regs_get_register(regs, argument_offs[n]);
+}
+
 #define arch_has_single_step()	(1)
 #ifdef CONFIG_X86_DEBUGCTLMSR
 #define arch_has_block_step()	(1)

index 1d0554c6bb34..cab5efe0a66c 100644
@@ -457,13 +457,15 @@ static int create_trace_kprobe(int argc, char **argv)
 	unsigned long offset = 0;
 	void *addr = NULL;
 	char buf[MAX_EVENT_NAME_LEN];
+	unsigned int flags = TPARG_FL_KERNEL;
 
 	/* argc must be >= 1 */
 	if (argv[0][0] == 'p')
 		is_return = false;
-	else if (argv[0][0] == 'r')
+	else if (argv[0][0] == 'r') {
 		is_return = true;
-	else if (argv[0][0] == '-')
+		flags |= TPARG_FL_RETURN;
+	} else if (argv[0][0] == '-')
 		is_delete = true;
 	else {
 		pr_info("Probe definition must be started with 'p', 'r' or"

@@ -546,8 +548,9 @@ static int create_trace_kprobe(int argc, char **argv)
 			pr_info("Failed to parse either an address or a symbol.\n");
 			return ret;
 		}
-		if (offset && is_return &&
-		    !kprobe_on_func_entry(NULL, symbol, offset)) {
+		if (kprobe_on_func_entry(NULL, symbol, offset))
+			flags |= TPARG_FL_FENTRY;
+		if (offset && is_return && !(flags & TPARG_FL_FENTRY)) {
 			pr_info("Given offset is not valid for return probe.\n");
 			return -EINVAL;
 		}

@@ -617,7 +620,7 @@ static int create_trace_kprobe(int argc, char **argv)
 
 		/* Parse fetch argument */
 		ret = traceprobe_parse_probe_arg(arg, &tk->tp.size, parg,
-						 is_return, true);
+						 flags);
 		if (ret) {
 			pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
 			goto error;

@@ -855,6 +858,11 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
 	case FETCH_OP_COMM:
 		val = (unsigned long)current->comm;
 		break;
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+	case FETCH_OP_ARG:
+		val = regs_get_kernel_argument(regs, code->param);
+		break;
+#endif
 	default:
 		return -EILSEQ;
 	}

index f56dfadd29d5..491a640a1a3e 100644
@@ -183,14 +183,13 @@ 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_insn *code, bool is_return,
-			    bool is_kprobe)
+			    struct fetch_insn *code, unsigned int flags)
 {
 	int ret = 0;
 	unsigned long param;
 
 	if (strcmp(arg, "retval") == 0) {
-		if (is_return)
+		if (flags & TPARG_FL_RETURN)
 			code->op = FETCH_OP_RETVAL;
 		else
 			ret = -EINVAL;

@@ -199,7 +198,8 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
 			code->op = FETCH_OP_STACKP;
 		} else if (isdigit(arg[5])) {
 			ret = kstrtoul(arg + 5, 10, &param);
-			if (ret || (is_kprobe && param > PARAM_MAX_STACK))
+			if (ret || ((flags & TPARG_FL_KERNEL) &&
+				    param > PARAM_MAX_STACK))
 				ret = -EINVAL;
 			else {
 				code->op = FETCH_OP_STACK;

@@ -209,6 +209,18 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
 			ret = -EINVAL;
 	} else if (strcmp(arg, "comm") == 0) {
 		code->op = FETCH_OP_COMM;
+#ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
+	} else if (((flags & TPARG_FL_MASK) ==
+		    (TPARG_FL_KERNEL | TPARG_FL_FENTRY)) &&
+		   strncmp(arg, "arg", 3) == 0) {
+		if (!isdigit(arg[3]))
+			return -EINVAL;
+		ret = kstrtoul(arg + 3, 10, &param);
+		if (ret || param > PARAM_MAX_STACK)
+			return -EINVAL;
+		code->op = FETCH_OP_ARG;
+		code->param = (unsigned int)param;
+#endif
 	} else
 		ret = -EINVAL;
 

@@ -219,7 +231,7 @@ static int parse_probe_vars(char *arg, const struct fetch_type *t,
 static int
 parse_probe_arg(char *arg, const struct fetch_type *type,
 		struct fetch_insn **pcode, struct fetch_insn *end,
-		bool is_return, bool is_kprobe)
+		unsigned int flags)
 {
 	struct fetch_insn *code = *pcode;
 	unsigned long param;

@@ -229,8 +241,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
 
 	switch (arg[0]) {
 	case '$':
-		ret = parse_probe_vars(arg + 1, type, code,
-					is_return, is_kprobe);
+		ret = parse_probe_vars(arg + 1, type, code, flags);
 		break;
 
 	case '%':	/* named register */

@@ -252,7 +263,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
 			code->immediate = param;
 		} else if (arg[1] == '+') {
 			/* kprobes don't support file offsets */
-			if (is_kprobe)
+			if (flags & TPARG_FL_KERNEL)
 				return -EINVAL;
 
 			ret = kstrtol(arg + 2, 0, &offset);

@@ -263,7 +274,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
 			code->immediate = (unsigned long)offset;  // imm64?
 		} else {
 			/* uprobes don't support symbols */
-			if (!is_kprobe)
+			if (!(flags & TPARG_FL_KERNEL))
 				return -EINVAL;
 
 			ret = traceprobe_split_symbol_offset(arg + 1, &offset);

@@ -304,8 +315,7 @@ parse_probe_arg(char *arg, const struct fetch_type *type,
 			const struct fetch_type *t2 = find_fetch_type(NULL);
 
 			*tmp = '\0';
-			ret = parse_probe_arg(arg, t2, &code, end, is_return,
-					      is_kprobe);
+			ret = parse_probe_arg(arg, t2, &code, end, flags);
 			if (ret)
 				break;
 			if (code->op == FETCH_OP_COMM)

@@ -365,7 +375,7 @@ static int __parse_bitfield_probe_arg(const char *bf,
 
 /* String length checking wrapper */
 int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
-		struct probe_arg *parg, bool is_return, bool is_kprobe)
+		struct probe_arg *parg, unsigned int flags)
 {
 	struct fetch_insn *code, *tmp = NULL;
 	const char *t;

@@ -405,7 +415,7 @@ int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
 	code[FETCH_INSN_MAX - 1].op = FETCH_OP_END;
 
 	ret = parse_probe_arg(arg, parg->type, &code, &code[FETCH_INSN_MAX - 1],
-			      is_return, is_kprobe);
+			      flags);
 	if (ret)
 		goto fail;
 

index 2234586b9942..c23aa7e20502 100644
@@ -35,6 +35,7 @@
 #include <linux/stringify.h>
 #include <linux/limits.h>
 #include <linux/uaccess.h>
+#include <linux/bitops.h>
 #include <asm/bitsperlong.h>
 
 #include "trace.h"

@@ -103,6 +104,7 @@ enum fetch_op {
 	FETCH_OP_RETVAL,	/* Return value */
 	FETCH_OP_IMM,		/* Immediate : .immediate */
 	FETCH_OP_COMM,		/* Current comm */
+	FETCH_OP_ARG,		/* Function argument : .param */
 	FETCH_OP_FOFFS,		/* File offset: .immediate */
 	// Stage 2 (dereference) op
 	FETCH_OP_DEREF,		/* Dereference: .offset */

@@ -260,8 +262,13 @@ find_event_file_link(struct trace_probe *tp, struct trace_event_file *file)
 	return NULL;
 }
 
+#define TPARG_FL_RETURN BIT(0)
+#define TPARG_FL_KERNEL BIT(1)
+#define TPARG_FL_FENTRY BIT(2)
+#define TPARG_FL_MASK	GENMASK(2, 0)
+
 extern int traceprobe_parse_probe_arg(char *arg, ssize_t *size,
-		   struct probe_arg *parg, bool is_return, bool is_kprobe);
+		   struct probe_arg *parg, unsigned int flags);
 
 extern int traceprobe_conflict_field_name(const char *name,
 			       struct probe_arg *args, int narg);

index 84692f564062..d6479af1e6ac 100644
@@ -556,7 +556,7 @@ static int create_trace_uprobe(int argc, char **argv)
 
 		/* Parse fetch argument */
 		ret = traceprobe_parse_probe_arg(arg, &tu->tp.size, parg,
-						 is_return, false);
+					is_return ? TPARG_FL_RETURN : 0);
 		if (ret) {
 			pr_info("Parse error at argument[%d]. (%d)\n", i, ret);
 			goto error;

index cab5efe0a66c..45e00de573d3 100644
@@ -835,8 +835,9 @@ static int
 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
 		   bool pre)
 {
+	struct fetch_insn *s3 = NULL;
 	unsigned long val;
-	int ret;
+	int ret, i = 0;
 
 	/* 1st stage: get value from context */
 	switch (code->op) {

@@ -877,6 +878,8 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
 		code++;
 	}
 
+stage3:
+	s3 = code;
 	/* 3rd stage: store value to buffer */
 	switch (code->op) {
 	case FETCH_OP_ST_RAW:

@@ -902,6 +905,16 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
 		code++;
 	}
 
+	/* the last stage: Loop on array */
+	if (code->op == FETCH_OP_LP_ARRAY) {
+		if (++i < code->param) {
+			code = s3;
+			val += s3->size;
+			dest += s3->size;
+			goto stage3;
+		}
+	}
+
 	return code->op == FETCH_OP_END ? 0 : -EILSEQ;
 }
 NOKPROBE_SYMBOL(process_fetch_insn)

@@ -1248,7 +1261,7 @@ static int register_kprobe_event(struct trace_kprobe *tk)
 		call->event.funcs = &kprobe_funcs;
 		call->class->define_fields = kprobe_event_define_fields;
 	}
-	if (set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0)
+	if (traceprobe_set_print_fmt(&tk->tp, trace_kprobe_is_return(tk)) < 0)
 		return -ENOMEM;
 	ret = register_trace_event(&call->event);
 	if (!ret) {

181 lines not on this page · raw message

index c23aa7e20502..62e68e4ef80b 100644
@@ -114,6 +114,8 @@ enum fetch_op {
 	FETCH_OP_ST_STRING,	/* String: .offset, .size */
 	// Stage 4 (modify) op
 	FETCH_OP_MOD_BF,	/* Bitfield: .basesize, .lshift, .rshift */
+	// Stage 5 (loop) op
+	FETCH_OP_LP_ARRAY,	/* Array: .param = loop count */
 	FETCH_OP_END,
 };
 

@@ -203,13 +205,16 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(symbol);
 	_ASSIGN_FETCH_TYPE(#ptype, ptype, ftype, sizeof(ftype), sign, atype)
 
 #define ASSIGN_FETCH_TYPE_END {}
+#define MAX_ARRAY_LEN	64
 
 struct probe_arg {
 	struct fetch_insn	*code;
 	bool			dynamic;/* Dynamic array (string) is used */
 	unsigned int		offset;	/* Offset from argument entry */
+	unsigned int		count;	/* Array count */
 	const char		*name;	/* Name of this argument */
 	const char		*comm;	/* Command of this argument */
+	char			*fmt;	/* Format string if needed */
 	const struct fetch_type	*type;	/* Type of this argument */
 };
 

@@ -385,16 +390,30 @@ static inline int
 print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
 		 u8 *data, void *field)
 {
-	int i;
+	void *p;
+	int i, j;
 
 	for (i = 0; i < nr_args; i++) {
-		trace_seq_printf(s, " %s=", args[i].name);
-		if (!args[i].type->print(s, data + args[i].offset, field))
-			return -ENOMEM;
+		struct probe_arg *a = args + i;
+
+		trace_seq_printf(s, " %s=", a->name);
+		if (likely(!a->count)) {
+			if (!a->type->print(s, data + a->offset, field))
+				return -ENOMEM;
+			continue;
+		}
+		trace_seq_putc(s, '{');
+		p = data + a->offset;
+		for (j = 0; j < a->count; j++) {
+			if (!a->type->print(s, p, field))
+				return -ENOMEM;
+			trace_seq_putc(s, j == a->count - 1 ? '}' : ',');
+			p += a->type->size;
+		}
 	}
 	return 0;
 }
 
-extern int set_print_fmt(struct trace_probe *tp, bool is_return);
+extern int traceprobe_set_print_fmt(struct trace_probe *tp, bool is_return);
 extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
 					size_t offset, struct trace_probe *tp);

index d6479af1e6ac..6fc7ea0159d4 100644
@@ -173,8 +173,9 @@ static int
 process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
 		   bool pre)
 {
+	struct fetch_insn *s3 = NULL;
 	unsigned long val;
-	int ret;
+	int ret, i = 0;
 
 	/* 1st stage: get value from context */
 	switch (code->op) {

@@ -210,6 +211,8 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
 		code++;
 	}
 
+stage3:
+	s3 = code;
 	/* 3rd stage: store value to buffer */
 	switch (code->op) {
 	case FETCH_OP_ST_RAW:

@@ -235,6 +238,16 @@ process_fetch_insn(struct fetch_insn *code, struct pt_regs *regs, void *dest,
 		code++;
 	}
 
+	/* the last stage: Loop on array */
+	if (code->op == FETCH_OP_LP_ARRAY) {
+		if (++i < code->param) {
+			code = s3;
+			val += s3->size;
+			dest += s3->size;
+			goto stage3;
+		}
+	}
+
 	return code->op == FETCH_OP_END ? 0 : -EILSEQ;
 }
 NOKPROBE_SYMBOL(process_fetch_insn)

@@ -1303,7 +1316,7 @@ static int register_uprobe_event(struct trace_uprobe *tu)
 	call->event.funcs = &uprobe_funcs;
 	call->class->define_fields = uprobe_event_define_fields;
 
-	if (set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
+	if (traceprobe_set_print_fmt(&tu->tp, is_ret_probe(tu)) < 0)
 		return -ENOMEM;
 
 	ret = register_trace_event(&call->event);