Commit 6674fdb2 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'trace-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 

Pull tracing fixes from Steven Rostedt:

 - Remove code I accidentally applied when doing a minor fix up to a
   patch, and then using "git commit -a --amend", which pulled in some
   other changes I was playing with.

 - Remove an used variable in trace_events_inject code

 - Fix function graph tracer when it traces a ftrace direct function.
   It will now ignore tracing a function that has a ftrace direct
   tramploine attached. This is needed for eBPF to use the ftrace direct
   code.

* tag 'trace-v5.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix function_graph tracer interaction with BPF trampoline
  tracing: remove set but not used variable 'buffer'
  module: Remove accidental change of module_enable_x()
parents d1c6a2aa ff205766

arch/x86/kernel/ftrace.c

+0 −14
Original line number Diff line number Diff line
@@ -1042,20 +1042,6 @@ void prepare_ftrace_return(unsigned long self_addr, unsigned long *parent, 
	if (unlikely(atomic_read(&current->tracing_graph_pause)))

		return;



	/*

	 * If the return location is actually pointing directly to

	 * the start of a direct trampoline (if we trace the trampoline

	 * it will still be offset by MCOUNT_INSN_SIZE), then the

	 * return address is actually off by one word, and we

	 * need to adjust for that.

	 */

	if (ftrace_direct_func_count) {

		if (ftrace_find_direct_func(self_addr + MCOUNT_INSN_SIZE)) {

			self_addr = *parent;

			parent++;

		}

	}



	/*

	 * Protect against fault, even if it shouldn't

	 * happen. This tool is too much intrusive to

include/linux/ftrace.h

+5 −0
Original line number Diff line number Diff line
@@ -264,6 +264,7 @@ int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 
				struct dyn_ftrace *rec,

				unsigned long old_addr,

				unsigned long new_addr);

unsigned long ftrace_find_rec_direct(unsigned long ip);

#else

# define ftrace_direct_func_count 0

static inline int register_ftrace_direct(unsigned long ip, unsigned long addr)
@@ -290,6 +291,10 @@ static inline int ftrace_modify_direct_caller(struct ftrace_func_entry *entry, 
{

	return -ENODEV;

}

static inline unsigned long ftrace_find_rec_direct(unsigned long ip)

{

	return 0;

}

#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */



#ifndef CONFIG_HAVE_DYNAMIC_FTRACE_WITH_DIRECT_CALLS

kernel/module.c

+1 −5
Original line number Diff line number Diff line
@@ -3730,6 +3730,7 @@ static int complete_formation(struct module *mod, struct load_info *info) 


	module_enable_ro(mod, false);

	module_enable_nx(mod);

	module_enable_x(mod);



	/* Mark state as coming so strong_try_module_get() ignores us,

	 * but kallsyms etc. can see us. */
@@ -3752,11 +3753,6 @@ static int prepare_coming_module(struct module *mod) 
	if (err)

		return err;



	/* Make module executable after ftrace is enabled */

	mutex_lock(&module_mutex);

	module_enable_x(mod);

	mutex_unlock(&module_mutex);



	blocking_notifier_call_chain(&module_notify_list,

				     MODULE_STATE_COMING, mod);

	return 0;

kernel/trace/fgraph.c

+9 −0
Original line number Diff line number Diff line
@@ -101,6 +101,15 @@ int function_graph_enter(unsigned long ret, unsigned long func, 
{

	struct ftrace_graph_ent trace;



	/*

	 * Skip graph tracing if the return location is served by direct trampoline,

	 * since call sequence and return addresses is unpredicatable anymore.

	 * Ex: BPF trampoline may call original function and may skip frame

	 * depending on type of BPF programs attached.

	 */

	if (ftrace_direct_func_count &&

	    ftrace_find_rec_direct(ret - MCOUNT_INSN_SIZE))

		return -EBUSY;

	trace.func = func;

	trace.depth = ++current->curr_ret_depth;

kernel/trace/ftrace.c

+7 −12
Original line number Diff line number Diff line
@@ -2364,7 +2364,7 @@ int ftrace_direct_func_count; 
 * Search the direct_functions hash to see if the given instruction pointer

 * has a direct caller attached to it.

 */

static unsigned long find_rec_direct(unsigned long ip)

unsigned long ftrace_find_rec_direct(unsigned long ip)

{

	struct ftrace_func_entry *entry;
@@ -2380,7 +2380,7 @@ static void call_direct_funcs(unsigned long ip, unsigned long pip, 
{

	unsigned long addr;



	addr = find_rec_direct(ip);

	addr = ftrace_find_rec_direct(ip);

	if (!addr)

		return;
@@ -2393,11 +2393,6 @@ struct ftrace_ops direct_ops = { 
			  | FTRACE_OPS_FL_DIRECT | FTRACE_OPS_FL_SAVE_REGS

			  | FTRACE_OPS_FL_PERMANENT,

};

#else

static inline unsigned long find_rec_direct(unsigned long ip)

{

	return 0;

}

#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */



/**
@@ -2417,7 +2412,7 @@ unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec) 


	if ((rec->flags & FTRACE_FL_DIRECT) &&

	    (ftrace_rec_count(rec) == 1)) {

		addr = find_rec_direct(rec->ip);

		addr = ftrace_find_rec_direct(rec->ip);

		if (addr)

			return addr;

		WARN_ON_ONCE(1);
@@ -2458,7 +2453,7 @@ unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec) 


	/* Direct calls take precedence over trampolines */

	if (rec->flags & FTRACE_FL_DIRECT_EN) {

		addr = find_rec_direct(rec->ip);

		addr = ftrace_find_rec_direct(rec->ip);

		if (addr)

			return addr;

		WARN_ON_ONCE(1);
@@ -3604,7 +3599,7 @@ static int t_show(struct seq_file *m, void *v) 
		if (rec->flags & FTRACE_FL_DIRECT) {

			unsigned long direct;



			direct = find_rec_direct(rec->ip);

			direct = ftrace_find_rec_direct(rec->ip);

			if (direct)

				seq_printf(m, "\n\tdirect-->%pS", (void *)direct);

		}
@@ -5008,7 +5003,7 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr) 
	mutex_lock(&direct_mutex);



	/* See if there's a direct function at @ip already */

	if (find_rec_direct(ip))

	if (ftrace_find_rec_direct(ip))

		goto out_unlock;



	ret = -ENODEV;
@@ -5027,7 +5022,7 @@ int register_ftrace_direct(unsigned long ip, unsigned long addr) 
	if (ip != rec->ip) {

		ip = rec->ip;

		/* Need to check this ip for a direct. */

		if (find_rec_direct(ip))

		if (ftrace_find_rec_direct(ip))

			goto out_unlock;

	}

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