Commit 9a3236ce authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'probes-fixes-v6.5-rc1' of... 

Merge tag 'probes-fixes-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull probes fixes from Masami Hiramatsu:

 - Fix fprobe's rethook release issues:

     - Release rethook after ftrace_ops is unregistered so that the
       rethook is not accessed after free.

     - Stop rethook before ftrace_ops is unregistered so that the
       rethook is NOT used after exiting unregister_fprobe()

 - Fix eprobe cleanup logic. If it attaches to multiple events and
   failes to enable one of them, rollback all enabled events correctly.

 - Fix fprobe to unlock ftrace recursion lock correctly when it missed
   by another running kprobe.

 - Cleanup kprobe to remove unnecessary NULL.

 - Cleanup kprobe to remove unnecessary 0 initializations.

* tag 'probes-fixes-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  fprobe: Ensure running fprobe_exit_handler() finished before calling rethook_free()
  kernel: kprobes: Remove unnecessary ‘0’ values
  kprobes: Remove unnecessary ‘NULL’ values from correct_ret_addr
  fprobe: add unlock to match a succeeded ftrace_test_recursion_trylock
  kernel/trace: Fix cleanup logic of enable_trace_eprobe
  fprobe: Release rethook after the ftrace_ops is unregistered
parents 1d754604 195b9cb5

include/linux/rethook.h

+1 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ struct rethook_node { 
};



struct rethook *rethook_alloc(void *data, rethook_handler_t handler);

void rethook_stop(struct rethook *rh);

void rethook_free(struct rethook *rh);

void rethook_add_node(struct rethook *rh, struct rethook_node *node);

struct rethook_node *rethook_try_get(struct rethook *rh);

kernel/kprobes.c

+4 −4
Original line number Diff line number Diff line
@@ -1072,7 +1072,7 @@ static int kprobe_ftrace_enabled; 
static int __arm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,

			       int *cnt)

{

	int ret = 0;

	int ret;



	lockdep_assert_held(&kprobe_mutex);
@@ -1110,7 +1110,7 @@ static int arm_kprobe_ftrace(struct kprobe *p) 
static int __disarm_kprobe_ftrace(struct kprobe *p, struct ftrace_ops *ops,

				  int *cnt)

{

	int ret = 0;

	int ret;



	lockdep_assert_held(&kprobe_mutex);
@@ -2007,9 +2007,9 @@ void __weak arch_kretprobe_fixup_return(struct pt_regs *regs, 
unsigned long __kretprobe_trampoline_handler(struct pt_regs *regs,

					     void *frame_pointer)

{

	kprobe_opcode_t *correct_ret_addr = NULL;

	struct kretprobe_instance *ri = NULL;

	struct llist_node *first, *node = NULL;

	kprobe_opcode_t *correct_ret_addr;

	struct kretprobe *rp;



	/* Find correct address and all nodes for this frame. */
@@ -2693,7 +2693,7 @@ void kprobe_free_init_mem(void) 


static int __init init_kprobes(void)

{

	int i, err = 0;

	int i, err;



	/* FIXME allocate the probe table, currently defined statically */

	/* initialize all list heads */

kernel/trace/fprobe.c

+7 −8
Original line number Diff line number Diff line
@@ -102,12 +102,14 @@ static void fprobe_kprobe_handler(unsigned long ip, unsigned long parent_ip, 


	if (unlikely(kprobe_running())) {

		fp->nmissed++;

		return;

		goto recursion_unlock;

	}



	kprobe_busy_begin();

	__fprobe_handler(ip, parent_ip, ops, fregs);

	kprobe_busy_end();



recursion_unlock:

	ftrace_test_recursion_unlock(bit);

}
@@ -371,19 +373,16 @@ int unregister_fprobe(struct fprobe *fp) 
	if (!fprobe_is_registered(fp))

		return -EINVAL;



	/*

	 * rethook_free() starts disabling the rethook, but the rethook handlers

	 * may be running on other processors at this point. To make sure that all

	 * current running handlers are finished, call unregister_ftrace_function()

	 * after this.

	 */

	if (fp->rethook)

		rethook_free(fp->rethook);

		rethook_stop(fp->rethook);



	ret = unregister_ftrace_function(&fp->ops);

	if (ret < 0)

		return ret;



	if (fp->rethook)

		rethook_free(fp->rethook);



	ftrace_free_filter(&fp->ops);



	return ret;

kernel/trace/rethook.c

+13 −0
Original line number Diff line number Diff line
@@ -53,6 +53,19 @@ static void rethook_free_rcu(struct rcu_head *head) 
		kfree(rh);

}



/**

 * rethook_stop() - Stop using a rethook.

 * @rh: the struct rethook to stop.

 *

 * Stop using a rethook to prepare for freeing it. If you want to wait for

 * all running rethook handler before calling rethook_free(), you need to

 * call this first and wait RCU, and call rethook_free().

 */

void rethook_stop(struct rethook *rh)

{

	WRITE_ONCE(rh->handler, NULL);

}



/**

 * rethook_free() - Free struct rethook.

 * @rh: the struct rethook to be freed.

kernel/trace/trace_eprobe.c

+16 −2
Original line number Diff line number Diff line
@@ -644,6 +644,7 @@ static int enable_trace_eprobe(struct trace_event_call *call, 
	struct trace_eprobe *ep;

	bool enabled;

	int ret = 0;

	int cnt = 0;



	tp = trace_probe_primary_from_call(call);

	if (WARN_ON_ONCE(!tp))
@@ -667,12 +668,25 @@ static int enable_trace_eprobe(struct trace_event_call *call, 
		if (ret)

			break;

		enabled = true;

		cnt++;

	}



	if (ret) {

		/* Failed to enable one of them. Roll back all */

		if (enabled)

		if (enabled) {

			/*

			 * It's a bug if one failed for something other than memory

			 * not being available but another eprobe succeeded.

			 */

			WARN_ON_ONCE(ret != -ENOMEM);



			list_for_each_entry(pos, trace_probe_probe_list(tp), list) {

				ep = container_of(pos, struct trace_eprobe, tp);

				disable_eprobe(ep, file->tr);

				if (!--cnt)

					break;

			}

		}

		if (file)

			trace_probe_remove_file(tp, file);

		else