Commit 123d6455 authored by Wang Jingjin's avatar Wang Jingjin Committed by Steven Rostedt (Google)
Browse files

ftrace: Fix build warning for ops_references_rec() not used 

The change that made IPMODIFY and DIRECT ops work together needed access
to the ops_references_ip() function, which it pulled out of the module
only code. But now if both CONFIG_MODULES and
CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS is not set, we get the below
warning:

    ‘ops_references_rec’ defined but not used.

Since ops_references_rec() only calls ops_references_ip() replace the
usage of ops_references_rec() with ops_references_ip() and encompass the
function with an #ifdef of DIRECT_CALLS || MODULES being defined.

Link: https://lkml.kernel.org/r/20220801084745.1187987-1-wangjingjin1@huawei.com



Fixes: 53cd885b ("ftrace: Allow IPMODIFY and DIRECT ops on the same function")
Signed-off-by: default avatarWang Jingjin <wangjingjin1@huawei.com>
Signed-off-by: default avatarSteven Rostedt (Google) <rostedt@goodmis.org>
parent 1c23f9e6

kernel/trace/ftrace.c

+33 −46
Original line number Diff line number Diff line
@@ -1861,8 +1861,6 @@ static void ftrace_hash_rec_enable_modify(struct ftrace_ops *ops, 
	ftrace_hash_rec_update_modify(ops, filter_hash, 1);

}



static bool ops_references_ip(struct ftrace_ops *ops, unsigned long ip);



/*

 * Try to update IPMODIFY flag on each ftrace_rec. Return 0 if it is OK

 * or no-needed to update, -EBUSY if it detects a conflict of the flag
@@ -3118,49 +3116,6 @@ static inline int ops_traces_mod(struct ftrace_ops *ops) 
		ftrace_hash_empty(ops->func_hash->notrace_hash);

}



/*

 * Check if the current ops references the given ip.

 *

 * If the ops traces all functions, then it was already accounted for.

 * If the ops does not trace the current record function, skip it.

 * If the ops ignores the function via notrace filter, skip it.

 */

static bool

ops_references_ip(struct ftrace_ops *ops, unsigned long ip)

{

	/* If ops isn't enabled, ignore it */

	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))

		return false;



	/* If ops traces all then it includes this function */

	if (ops_traces_mod(ops))

		return true;



	/* The function must be in the filter */

	if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&

	    !__ftrace_lookup_ip(ops->func_hash->filter_hash, ip))

		return false;



	/* If in notrace hash, we ignore it too */

	if (ftrace_lookup_ip(ops->func_hash->notrace_hash, ip))

		return false;



	return true;

}



/*

 * Check if the current ops references the record.

 *

 * If the ops traces all functions, then it was already accounted for.

 * If the ops does not trace the current record function, skip it.

 * If the ops ignores the function via notrace filter, skip it.

 */

static bool

ops_references_rec(struct ftrace_ops *ops, struct dyn_ftrace *rec)

{

	return ops_references_ip(ops, rec->ip);

}



static int ftrace_update_code(struct module *mod, struct ftrace_page *new_pgs)

{

	bool init_nop = ftrace_need_init_nop();
@@ -6822,6 +6777,38 @@ static int ftrace_get_trampoline_kallsym(unsigned int symnum, 
	return -ERANGE;

}



#if defined(CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS) || defined(CONFIG_MODULES)

/*

 * Check if the current ops references the given ip.

 *

 * If the ops traces all functions, then it was already accounted for.

 * If the ops does not trace the current record function, skip it.

 * If the ops ignores the function via notrace filter, skip it.

 */

static bool

ops_references_ip(struct ftrace_ops *ops, unsigned long ip)

{

	/* If ops isn't enabled, ignore it */

	if (!(ops->flags & FTRACE_OPS_FL_ENABLED))

		return false;



	/* If ops traces all then it includes this function */

	if (ops_traces_mod(ops))

		return true;



	/* The function must be in the filter */

	if (!ftrace_hash_empty(ops->func_hash->filter_hash) &&

	    !__ftrace_lookup_ip(ops->func_hash->filter_hash, ip))

		return false;



	/* If in notrace hash, we ignore it too */

	if (ftrace_lookup_ip(ops->func_hash->notrace_hash, ip))

		return false;



	return true;

}

#endif



#ifdef CONFIG_MODULES



#define next_to_ftrace_page(p) container_of(p, struct ftrace_page, next)
@@ -6834,7 +6821,7 @@ static int referenced_filters(struct dyn_ftrace *rec) 
	int cnt = 0;



	for (ops = ftrace_ops_list; ops != &ftrace_list_end; ops = ops->next) {

		if (ops_references_rec(ops, rec)) {

		if (ops_references_ip(ops, rec->ip)) {

			if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_DIRECT))

				continue;

			if (WARN_ON_ONCE(ops->flags & FTRACE_OPS_FL_IPMODIFY))