Merge tag 'probes-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes updates from Masami Hiramatsu:

 - kprobes: use struct_size() for variable size kretprobe_instance data
   structure.

 - eprobe: Simplify trace_eprobe list iteration.

 - probe events: Data structure field access support on BTF argument.

     - Update BTF argument support on the functions in the kernel
       loadable modules (only loaded modules are supported).

     - Move generic BTF access function (search function prototype and
       get function parameters) to a separated file.

     - Add a function to search a member of data structure in BTF.

     - Support accessing BTF data structure member from probe args by
       C-like arrow('->') and dot('.') operators. e.g.
          't sched_switch next=next->pid vruntime=next->se.vruntime'

     - Support accessing BTF data structure member from $retval. e.g.
          'f getname_flags%return +0($retval->name):string'

     - Add string type checking if BTF type info is available. This will
       reject if user specify ":string" type for non "char pointer"
       type.

     - Automatically assume the fprobe event as a function return event
       if $retval is used.

 - selftests/ftrace: Add BTF data field access test cases.

 - Documentation: Update fprobe event example with BTF data field.

* tag 'probes-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  Documentation: tracing: Update fprobe event example with BTF field
  selftests/ftrace: Add BTF fields access testcases
  tracing/fprobe-event: Assume fprobe is a return event by $retval
  tracing/probes: Add string type check with BTF
  tracing/probes: Support BTF field access from $retval
  tracing/probes: Support BTF based data structure field access
  tracing/probes: Add a function to search a member of a struct/union
  tracing/probes: Move finding func-proto API and getting func-param API to trace_btf
  tracing/probes: Support BTF argument on module functions
  tracing/eprobe: Iterate trace_eprobe directly
  kernel: kprobes: Use struct_size()

1 files changed, 23 insertions, 4 deletions

diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 7dde806be91e..02b432ae7513 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -383,9 +383,15 @@ static inline bool tparg_is_function_entry(unsigned int flags)
 
 struct traceprobe_parse_context {
 	struct trace_event_call *event;
-	const struct btf_param *params;
-	s32 nr_params;
-	const char *funcname;
+	/* BTF related parameters */
+	const char *funcname;		/* Function name in BTF */
+	const struct btf_type  *proto;	/* Prototype of the function */
+	const struct btf_param *params;	/* Parameter of the function */
+	s32 nr_params;			/* The number of the parameters */
+	struct btf *btf;		/* The BTF to be used */
+	const struct btf_type *last_type;	/* Saved type */
+	u32 last_bitoffs;		/* Saved bitoffs */
+	u32 last_bitsize;		/* Saved bitsize */
 	unsigned int flags;
 	int offset;
 };
@@ -400,6 +406,12 @@ const char **traceprobe_expand_meta_args(int argc, const char *argv[],
 extern int traceprobe_update_arg(struct probe_arg *arg);
 extern void traceprobe_free_probe_arg(struct probe_arg *arg);
 
+/*
+ * If either traceprobe_parse_probe_arg() or traceprobe_expand_meta_args() is called,
+ * this MUST be called for clean up the context and return a resource.
+ */
+void traceprobe_finish_parse(struct traceprobe_parse_context *ctx);
+
 extern int traceprobe_split_symbol_offset(char *symbol, long *offset);
 int traceprobe_parse_event_name(const char **pevent, const char **pgroup,
 				char *buf, int offset);
@@ -495,7 +507,14 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
 	C(BAD_VAR_ARGS,		"$arg* must be an independent parameter without name etc."),\
 	C(NOFENTRY_ARGS,	"$arg* can be used only on function entry"),	\
 	C(DOUBLE_ARGS,		"$arg* can be used only once in the parameters"),	\
-	C(ARGS_2LONG,		"$arg* failed because the argument list is too long"),
+	C(ARGS_2LONG,		"$arg* failed because the argument list is too long"),	\
+	C(ARGIDX_2BIG,		"$argN index is too big"),		\
+	C(NO_PTR_STRCT,		"This is not a pointer to union/structure."),	\
+	C(NOSUP_DAT_ARG,	"Non pointer structure/union argument is not supported."),\
+	C(BAD_HYPHEN,		"Failed to parse single hyphen. Forgot '>'?"),	\
+	C(NO_BTF_FIELD,		"This field is not found."),	\
+	C(BAD_BTF_TID,		"Failed to get BTF type info."),\
+	C(BAD_TYPE4STR,		"This type does not fit for string."),
 
 #undef C
 #define C(a, b)		TP_ERR_##a