Merge tag 'probes-v6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull kprobes cleanup updates from Masami Hiramatsu:
 "These are probe events cleanups, no new features but improve
  readability:

   - Rename print_probe_args() to trace_probe_print_args() and
     un-inline it

   - Introduce a set of default data fetch functions for dynamic
     probe events

   - Extract common code of data fetch process of dynamic probe events"

* tag 'probes-v6.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  kernel/trace: extract common part in process_fetch_insn
  kernel/trace: Provide default impelentations defined in trace_probe_tmpl.h
  kernel/trace: Introduce trace_probe_print_args and use it in *probes

kernel/trace/trace_eprobe.c

@@ -311,7 +311,7 @@ print_eprobe_event(struct trace_iterator *iter, int flags,
 
 	trace_seq_putc(s, ')');
 
-	if (print_probe_args(s, tp->args, tp->nr_args,
+	if (trace_probe_print_args(s, tp->args, tp->nr_args,
 			     (u8 *)&field[1], field) < 0)
 		goto out;
 
@@ -320,7 +320,8 @@ print_eprobe_event(struct trace_iterator *iter, int flags,
 	return trace_handle_return(s);
 }
 
-static unsigned long get_event_field(struct fetch_insn *code, void *rec)
+static nokprobe_inline unsigned long
+get_event_field(struct fetch_insn *code, void *rec)
 {
 	struct ftrace_event_field *field = code->data;
 	unsigned long val;
@@ -395,19 +396,11 @@ static int get_eprobe_size(struct trace_probe *tp, void *rec)
 			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:
+				if (process_common_fetch_insn(code, &val) < 0)
 					continue;
 			}
 			code++;
@@ -428,84 +421,26 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 		   void *base)
 {
 	unsigned long val;
+	int ret;
 
  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:
-		return -EILSEQ;
+		ret = process_common_fetch_insn(code, &val);
+		if (ret < 0)
+			return ret;
 	}
 	code++;
 	return process_fetch_insn_bottom(code, val, dest, base);
 }
 NOKPROBE_SYMBOL(process_fetch_insn)
 
-/* Return the length of string -- including null terminal byte */
-static nokprobe_inline int
-fetch_store_strlen_user(unsigned long addr)
-{
-	return kern_fetch_store_strlen_user(addr);
-}
-
-/* Return the length of string -- including null terminal byte */
-static nokprobe_inline int
-fetch_store_strlen(unsigned long addr)
-{
-	return kern_fetch_store_strlen(addr);
-}
-
-/*
- * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
- * with max length and relative data location.
- */
-static nokprobe_inline int
-fetch_store_string_user(unsigned long addr, void *dest, void *base)
-{
-	return kern_fetch_store_string_user(addr, dest, base);
-}
-
-/*
- * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
- * length and relative data location.
- */
-static nokprobe_inline int
-fetch_store_string(unsigned long addr, void *dest, void *base)
-{
-	return kern_fetch_store_string(addr, dest, base);
-}
-
-static nokprobe_inline int
-probe_mem_read_user(void *dest, void *src, size_t size)
-{
-	const void __user *uaddr =  (__force const void __user *)src;
-
-	return copy_from_user_nofault(dest, uaddr, size);
-}
-
-static nokprobe_inline int
-probe_mem_read(void *dest, void *src, size_t size)
-{
-#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
-	if ((unsigned long)src < TASK_SIZE)
-		return probe_mem_read_user(dest, src, size);
-#endif
-	return copy_from_kernel_nofault(dest, src, size);
-}
-
 /* eprobe handler */
 static inline void
 __eprobe_trace_func(struct eprobe_data *edata, void *rec)

kernel/trace/trace_events_synth.c

@@ -448,12 +448,12 @@ static unsigned int trace_string(struct synth_trace_event *entry,
 		data_offset = struct_size(entry, fields, event->n_u64);
 		data_offset += data_size;
 
-		len = kern_fetch_store_strlen((unsigned long)str_val);
+		len = fetch_store_strlen((unsigned long)str_val);
 
 		data_offset |= len << 16;
 		*(u32 *)&entry->fields[*n_u64] = data_offset;
 
-		ret = kern_fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
+		ret = fetch_store_string((unsigned long)str_val, &entry->fields[*n_u64], entry);
 
 		(*n_u64)++;
 	} else {
@@ -542,7 +542,7 @@ static notrace void trace_event_raw_event_synth(void *__data,
 			len = *((unsigned long *)str_val);
 			len *= sizeof(unsigned long);
 		} else {
-			len = kern_fetch_store_strlen((unsigned long)str_val);
+			len = fetch_store_strlen((unsigned long)str_val);
 		}
 
 		fields_size += len;

kernel/trace/trace_kprobe.c

@@ -1218,60 +1218,6 @@ 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 int
-fetch_store_strlen_user(unsigned long addr)
-{
-	return kern_fetch_store_strlen_user(addr);
-}
-
-/* Return the length of string -- including null terminal byte */
-static nokprobe_inline int
-fetch_store_strlen(unsigned long addr)
-{
-	return kern_fetch_store_strlen(addr);
-}
-
-/*
- * Fetch a null-terminated string from user. Caller MUST set *(u32 *)buf
- * with max length and relative data location.
- */
-static nokprobe_inline int
-fetch_store_string_user(unsigned long addr, void *dest, void *base)
-{
-	return kern_fetch_store_string_user(addr, dest, base);
-}
-
-/*
- * Fetch a null-terminated string. Caller MUST set *(u32 *)buf with max
- * length and relative data location.
- */
-static nokprobe_inline int
-fetch_store_string(unsigned long addr, void *dest, void *base)
-{
-	return kern_fetch_store_string(addr, dest, base);
-}
-
-static nokprobe_inline int
-probe_mem_read_user(void *dest, void *src, size_t size)
-{
-	const void __user *uaddr =  (__force const void __user *)src;
-
-	return copy_from_user_nofault(dest, uaddr, size);
-}
-
-static nokprobe_inline int
-probe_mem_read(void *dest, void *src, size_t size)
-{
-#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
-	if ((unsigned long)src < TASK_SIZE)
-		return probe_mem_read_user(dest, src, size);
-#endif
-	return copy_from_kernel_nofault(dest, src, size);
-}
-
 /* 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, void *rec, void *dest,
@@ -1279,6 +1225,7 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 {
 	struct pt_regs *regs = rec;
 	unsigned long val;
+	int ret;
 
 retry:
 	/* 1st stage: get value from context */
@@ -1295,15 +1242,6 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 	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;
-	case FETCH_OP_DATA:
-		val = (unsigned long)code->data;
-		break;
 #ifdef CONFIG_HAVE_FUNCTION_ARG_ACCESS_API
 	case FETCH_OP_ARG:
 		val = regs_get_kernel_argument(regs, code->param);
@@ -1313,7 +1251,9 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 		code++;
 		goto retry;
 	default:
-		return -EILSEQ;
+		ret = process_common_fetch_insn(code, &val);
+		if (ret < 0)
+			return ret;
 	}
 	code++;
 
@@ -1424,7 +1364,7 @@ print_kprobe_event(struct trace_iterator *iter, int flags,
 
 	trace_seq_putc(s, ')');
 
-	if (print_probe_args(s, tp->args, tp->nr_args,
+	if (trace_probe_print_args(s, tp->args, tp->nr_args,
 			     (u8 *)&field[1], field) < 0)
 		goto out;
 
@@ -1459,7 +1399,7 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,
 
 	trace_seq_putc(s, ')');
 
-	if (print_probe_args(s, tp->args, tp->nr_args,
+	if (trace_probe_print_args(s, tp->args, tp->nr_args,
 			     (u8 *)&field[1], field) < 0)
 		goto out;
 

kernel/trace/trace_probe.c

@@ -1239,3 +1239,30 @@ int trace_probe_create(const char *raw_command, int (*createfn)(int, const char
 
 	return ret;
 }
+
+int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
+		 u8 *data, void *field)
+{
+	void *p;
+	int i, j;
+
+	for (i = 0; i < nr_args; i++) {
+		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;
+}

kernel/trace/trace_probe.h

@@ -349,6 +349,8 @@ int trace_probe_compare_arg_type(struct trace_probe *a, struct trace_probe *b);
 bool trace_probe_match_command_args(struct trace_probe *tp,
 				    int argc, const char **argv);
 int trace_probe_create(const char *raw_command, int (*createfn)(int, const char **));
+int trace_probe_print_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
+		 u8 *data, void *field);
 
 #define trace_probe_for_each_link(pos, tp)	\
 	list_for_each_entry(pos, &(tp)->event->files, list)

kernel/trace/trace_probe_kernel.h

@@ -12,7 +12,7 @@
  */
 /* Return the length of string -- including null terminal byte */
 static nokprobe_inline int
-kern_fetch_store_strlen_user(unsigned long addr)
+fetch_store_strlen_user(unsigned long addr)
 {
 	const void __user *uaddr =  (__force const void __user *)addr;
 	int ret;
@@ -29,14 +29,14 @@ kern_fetch_store_strlen_user(unsigned long addr)
 
 /* Return the length of string -- including null terminal byte */
 static nokprobe_inline int
-kern_fetch_store_strlen(unsigned long addr)
+fetch_store_strlen(unsigned long addr)
 {
 	int ret, len = 0;
 	u8 c;
 
 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	if (addr < TASK_SIZE)
-		return kern_fetch_store_strlen_user(addr);
+		return fetch_store_strlen_user(addr);
 #endif
 
 	do {
@@ -63,7 +63,7 @@ static nokprobe_inline void set_data_loc(int ret, void *dest, void *__dest, void
  * with max length and relative data location.
  */
 static nokprobe_inline int
-kern_fetch_store_string_user(unsigned long addr, void *dest, void *base)
+fetch_store_string_user(unsigned long addr, void *dest, void *base)
 {
 	const void __user *uaddr =  (__force const void __user *)addr;
 	int maxlen = get_loc_len(*(u32 *)dest);
@@ -86,7 +86,7 @@ kern_fetch_store_string_user(unsigned long addr, void *dest, void *base)
  * length and relative data location.
  */
 static nokprobe_inline int
-kern_fetch_store_string(unsigned long addr, void *dest, void *base)
+fetch_store_string(unsigned long addr, void *dest, void *base)
 {
 	int maxlen = get_loc_len(*(u32 *)dest);
 	void *__dest;
@@ -94,7 +94,7 @@ kern_fetch_store_string(unsigned long addr, void *dest, void *base)
 
 #ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
 	if ((unsigned long)addr < TASK_SIZE)
-		return kern_fetch_store_string_user(addr, dest, base);
+		return fetch_store_string_user(addr, dest, base);
 #endif
 
 	if (unlikely(!maxlen))
@@ -112,4 +112,22 @@ kern_fetch_store_string(unsigned long addr, void *dest, void *base)
 	return ret;
 }
 
+static nokprobe_inline int
+probe_mem_read_user(void *dest, void *src, size_t size)
+{
+	const void __user *uaddr =  (__force const void __user *)src;
+
+	return copy_from_user_nofault(dest, uaddr, size);
+}
+
+static nokprobe_inline int
+probe_mem_read(void *dest, void *src, size_t size)
+{
+#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE
+	if ((unsigned long)src < TASK_SIZE)
+		return probe_mem_read_user(dest, src, size);
+#endif
+	return copy_from_kernel_nofault(dest, src, size);
+}
+
 #endif /* __TRACE_PROBE_KERNEL_H_ */

kernel/trace/trace_probe_tmpl.h

@@ -98,6 +98,26 @@ fetch_store_symstring(unsigned long addr, void *dest, void *base)
 	return sprint_symbol(__dest, addr);
 }
 
+/* common part of process_fetch_insn*/
+static nokprobe_inline int
+process_common_fetch_insn(struct fetch_insn *code, unsigned long *val)
+{
+	switch (code->op) {
+	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;
+	default:
+		return -EILSEQ;
+	}
+	return 0;
+}
+
 /* From the 2nd stage, routine is same */
 static nokprobe_inline int
 process_fetch_insn_bottom(struct fetch_insn *code, unsigned long val,
@@ -253,31 +273,3 @@ store_trace_args(void *data, struct trace_probe *tp, void *rec,
 		}
 	}
 }
-
-static inline int
-print_probe_args(struct trace_seq *s, struct probe_arg *args, int nr_args,
-		 u8 *data, void *field)
-{
-	void *p;
-	int i, j;
-
-	for (i = 0; i < nr_args; i++) {
-		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;
-}

kernel/trace/trace_uprobe.c

@@ -220,6 +220,7 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 {
 	struct pt_regs *regs = rec;
 	unsigned long val;
+	int ret;
 
 	/* 1st stage: get value from context */
 	switch (code->op) {
@@ -235,20 +236,16 @@ process_fetch_insn(struct fetch_insn *code, void *rec, void *dest,
 	case FETCH_OP_RETVAL:
 		val = regs_return_value(regs);
 		break;
-	case FETCH_OP_IMM:
-		val = code->immediate;
-		break;
 	case FETCH_OP_COMM:
 		val = FETCH_TOKEN_COMM;
 		break;
-	case FETCH_OP_DATA:
-		val = (unsigned long)code->data;
-		break;
 	case FETCH_OP_FOFFS:
 		val = translate_user_vaddr(code->immediate);
 		break;
 	default:
-		return -EILSEQ;
+		ret = process_common_fetch_insn(code, &val);
+		if (ret < 0)
+			return ret;
 	}
 	code++;
 
@@ -1042,7 +1039,7 @@ print_uprobe_event(struct trace_iterator *iter, int flags, struct trace_event *e
 		data = DATAOF_TRACE_ENTRY(entry, false);
 	}
 
-	if (print_probe_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
+	if (trace_probe_print_args(s, tu->tp.args, tu->tp.nr_args, data, entry) < 0)
 		goto out;
 
 	trace_seq_putc(s, '\n');