Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 638 insertions, 0 deletions

diff --git a/tools/perf/util/thread.c b/tools/perf/util/thread.c
new file mode 100644
index 000000000..e483ffcb5
--- /dev/null
+++ b/tools/perf/util/thread.c
@@ -0,0 +1,638 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <elf.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <linux/kernel.h>
+#include <linux/zalloc.h>
+#include "dso.h"
+#include "session.h"
+#include "thread.h"
+#include "thread-stack.h"
+#include "debug.h"
+#include "namespaces.h"
+#include "comm.h"
+#include "map.h"
+#include "symbol.h"
+#include "unwind.h"
+#include "callchain.h"
+#include "dwarf-regs.h"
+
+#include <api/fs/fs.h>
+
+int thread__init_maps(struct thread *thread, struct machine *machine)
+{
+	pid_t pid = thread__pid(thread);
+
+	if (pid == thread__tid(thread) || pid == -1) {
+		thread__set_maps(thread, maps__new(machine));
+	} else {
+		struct thread *leader = machine__findnew_thread(machine, pid, pid);
+
+		if (leader) {
+			thread__set_maps(thread, maps__get(thread__maps(leader)));
+			thread__put(leader);
+		}
+	}
+
+	return thread__maps(thread) ? 0 : -1;
+}
+
+struct thread *thread__new(pid_t pid, pid_t tid)
+	NO_THREAD_SAFETY_ANALYSIS /* Allocation/creation is inherently single threaded. */
+{
+	RC_STRUCT(thread) *_thread = zalloc(sizeof(*_thread));
+	struct thread *thread;
+
+	if (ADD_RC_CHK(thread, _thread) != NULL) {
+		struct comm *comm;
+		char comm_str[32];
+
+		thread__set_pid(thread, pid);
+		thread__set_tid(thread, tid);
+		thread__set_ppid(thread, -1);
+		thread__set_cpu(thread, -1);
+		thread__set_guest_cpu(thread, -1);
+		thread__set_e_machine(thread, EM_NONE);
+		thread__set_e_is_big_endian(thread, false);
+		thread__set_lbr_stitch_enable(thread, false);
+		INIT_LIST_HEAD(thread__namespaces_list(thread));
+		INIT_LIST_HEAD(thread__comm_list(thread));
+		init_rwsem(thread__namespaces_lock(thread));
+		init_rwsem(thread__comm_lock(thread));
+
+		snprintf(comm_str, sizeof(comm_str), ":%d", tid);
+		comm = comm__new(comm_str, 0, false);
+		if (!comm)
+			goto err_thread;
+
+		list_add(&comm->list, thread__comm_list(thread));
+		refcount_set(thread__refcnt(thread), 1);
+		/* Thread holds first ref to nsdata. */
+		RC_CHK_ACCESS(thread)->nsinfo = nsinfo__new(pid);
+		srccode_state_init(thread__srccode_state(thread));
+	}
+
+	return thread;
+
+err_thread:
+	thread__delete(thread);
+	return NULL;
+}
+
+static void (*thread__priv_destructor)(void *priv);
+
+void thread__set_priv_destructor(void (*destructor)(void *priv))
+{
+	assert(thread__priv_destructor == NULL);
+
+	thread__priv_destructor = destructor;
+}
+
+void thread__delete(struct thread *thread)
+{
+	struct namespaces *namespaces, *tmp_namespaces;
+	struct comm *comm, *tmp_comm;
+
+	thread_stack__free(thread);
+
+	if (thread__maps(thread)) {
+		maps__put(thread__maps(thread));
+		thread__set_maps(thread, NULL);
+	}
+	down_write(thread__namespaces_lock(thread));
+	list_for_each_entry_safe(namespaces, tmp_namespaces,
+				 thread__namespaces_list(thread), list) {
+		list_del_init(&namespaces->list);
+		namespaces__free(namespaces);
+	}
+	up_write(thread__namespaces_lock(thread));
+
+	down_write(thread__comm_lock(thread));
+	list_for_each_entry_safe(comm, tmp_comm, thread__comm_list(thread), list) {
+		list_del_init(&comm->list);
+		comm__free(comm);
+	}
+	up_write(thread__comm_lock(thread));
+
+	nsinfo__zput(RC_CHK_ACCESS(thread)->nsinfo);
+	srccode_state_free(thread__srccode_state(thread));
+
+	exit_rwsem(thread__namespaces_lock(thread));
+	exit_rwsem(thread__comm_lock(thread));
+	thread__free_stitch_list(thread);
+
+	if (thread__priv_destructor)
+		thread__priv_destructor(thread__priv(thread));
+
+	RC_CHK_FREE(thread);
+}
+
+struct thread *thread__get(struct thread *thread)
+{
+	struct thread *result;
+
+	if (RC_CHK_GET(result, thread))
+		refcount_inc(thread__refcnt(thread));
+
+	return result;
+}
+
+void thread__put(struct thread *thread)
+{
+	if (thread && refcount_dec_and_test(thread__refcnt(thread)))
+		thread__delete(thread);
+	else
+		RC_CHK_PUT(thread);
+}
+
+static struct namespaces *__thread__namespaces(struct thread *thread)
+{
+	if (list_empty(thread__namespaces_list(thread)))
+		return NULL;
+
+	return list_first_entry(thread__namespaces_list(thread), struct namespaces, list);
+}
+
+struct namespaces *thread__namespaces(struct thread *thread)
+{
+	struct namespaces *ns;
+
+	down_read(thread__namespaces_lock(thread));
+	ns = __thread__namespaces(thread);
+	up_read(thread__namespaces_lock(thread));
+
+	return ns;
+}
+
+static int __thread__set_namespaces(struct thread *thread, u64 timestamp,
+				    struct perf_record_namespaces *event)
+{
+	struct namespaces *new, *curr = __thread__namespaces(thread);
+
+	new = namespaces__new(event);
+	if (!new)
+		return -ENOMEM;
+
+	list_add(&new->list, thread__namespaces_list(thread));
+
+	if (timestamp && curr) {
+		/*
+		 * setns syscall must have changed few or all the namespaces
+		 * of this thread. Update end time for the namespaces
+		 * previously used.
+		 */
+		curr = list_next_entry(new, list);
+		curr->end_time = timestamp;
+	}
+
+	return 0;
+}
+
+int thread__set_namespaces(struct thread *thread, u64 timestamp,
+			   struct perf_record_namespaces *event)
+{
+	int ret;
+
+	down_write(thread__namespaces_lock(thread));
+	ret = __thread__set_namespaces(thread, timestamp, event);
+	up_write(thread__namespaces_lock(thread));
+	return ret;
+}
+
+static struct comm *__thread__comm(struct thread *thread)
+	SHARED_LOCKS_REQUIRED(thread__comm_lock(thread))
+{
+	if (list_empty(thread__comm_list(thread)))
+		return NULL;
+
+	return list_first_entry(thread__comm_list(thread), struct comm, list);
+}
+
+struct comm *thread__comm(struct thread *thread)
+{
+	struct comm *res = NULL;
+
+	down_read(thread__comm_lock(thread));
+	res = __thread__comm(thread);
+	up_read(thread__comm_lock(thread));
+	return res;
+}
+
+struct comm *thread__exec_comm(struct thread *thread)
+{
+	struct comm *comm, *last = NULL, *second_last = NULL;
+
+	down_read(thread__comm_lock(thread));
+	list_for_each_entry(comm, thread__comm_list(thread), list) {
+		if (comm->exec) {
+			up_read(thread__comm_lock(thread));
+			return comm;
+		}
+		second_last = last;
+		last = comm;
+	}
+	up_read(thread__comm_lock(thread));
+
+	/*
+	 * 'last' with no start time might be the parent's comm of a synthesized
+	 * thread (created by processing a synthesized fork event). For a main
+	 * thread, that is very probably wrong. Prefer a later comm to avoid
+	 * that case.
+	 */
+	if (second_last && !last->start && thread__pid(thread) == thread__tid(thread))
+		return second_last;
+
+	return last;
+}
+
+static int ____thread__set_comm(struct thread *thread, const char *str,
+				u64 timestamp, bool exec)
+	EXCLUSIVE_LOCKS_REQUIRED(thread__comm_lock(thread))
+{
+	struct comm *new, *curr = __thread__comm(thread);
+
+	/* Override the default :tid entry */
+	if (!thread__comm_set(thread)) {
+		int err = comm__override(curr, str, timestamp, exec);
+		if (err)
+			return err;
+	} else {
+		new = comm__new(str, timestamp, exec);
+		if (!new)
+			return -ENOMEM;
+		list_add(&new->list, thread__comm_list(thread));
+
+		if (exec)
+			unwind__flush_access(thread__maps(thread));
+	}
+
+	thread__set_comm_set(thread, true);
+
+	return 0;
+}
+
+int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
+		       bool exec)
+{
+	int ret;
+
+	down_write(thread__comm_lock(thread));
+	ret = ____thread__set_comm(thread, str, timestamp, exec);
+	up_write(thread__comm_lock(thread));
+	return ret;
+}
+
+int thread__set_comm_from_proc(struct thread *thread)
+{
+	char path[64];
+	char *comm = NULL;
+	size_t sz;
+	int err = -1;
+
+	if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
+		       thread__pid(thread), thread__tid(thread)) >= (int)sizeof(path)) &&
+	    procfs__read_str(path, &comm, &sz) == 0) {
+		/* sz==0: read got nothing, e.g. race during exit teardown */
+		if (sz == 0) {
+			free(comm);
+			return -1;
+		}
+		comm[sz - 1] = '\0';
+		err = thread__set_comm(thread, comm, 0);
+	}
+
+	return err;
+}
+
+static const char *__thread__comm_str(struct thread *thread)
+	SHARED_LOCKS_REQUIRED(thread__comm_lock(thread))
+{
+	const struct comm *comm = __thread__comm(thread);
+
+	if (!comm)
+		return NULL;
+
+	return comm__str(comm);
+}
+
+const char *thread__comm_str(struct thread *thread)
+{
+	const char *str;
+
+	down_read(thread__comm_lock(thread));
+	str = __thread__comm_str(thread);
+	up_read(thread__comm_lock(thread));
+
+	return str;
+}
+
+static int __thread__comm_len(struct thread *thread, const char *comm)
+{
+	if (!comm)
+		return 0;
+	thread__set_comm_len(thread, strlen(comm));
+
+	return thread__var_comm_len(thread);
+}
+
+/* CHECKME: it should probably better return the max comm len from its comm list */
+int thread__comm_len(struct thread *thread)
+{
+	int comm_len = thread__var_comm_len(thread);
+
+	if (!comm_len) {
+		const char *comm;
+
+		down_read(thread__comm_lock(thread));
+		comm = __thread__comm_str(thread);
+		comm_len = __thread__comm_len(thread, comm);
+		up_read(thread__comm_lock(thread));
+	}
+
+	return comm_len;
+}
+
+size_t thread__fprintf(struct thread *thread, FILE *fp)
+{
+	return fprintf(fp, "Thread %d %s\n", thread__tid(thread), thread__comm_str(thread)) +
+	       maps__fprintf(thread__maps(thread), fp);
+}
+
+int thread__insert_map(struct thread *thread, struct map *map)
+{
+	int ret;
+	uint16_t e_machine;
+
+	ret = maps__fixup_overlap_and_insert(thread__maps(thread), map);
+	if (ret)
+		return ret;
+
+	e_machine = thread__e_machine(thread, /*machine=*/NULL, /*e_flags=*/NULL);
+	return unwind__prepare_access(thread__maps(thread), e_machine);
+}
+
+static int thread__prepare_access(struct thread *thread)
+{
+	uint16_t e_machine = thread__e_machine(thread, /*machine=*/NULL, /*e_flags=*/NULL);
+
+	return unwind__prepare_access(thread__maps(thread), e_machine);
+}
+
+static int thread__clone_maps(struct thread *thread, struct thread *parent, bool do_maps_clone)
+{
+	/* This is new thread, we share map groups for process. */
+	if (thread__pid(thread) == thread__pid(parent))
+		return thread__prepare_access(thread);
+
+	if (maps__equal(thread__maps(thread), thread__maps(parent))) {
+		pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
+			 thread__pid(thread), thread__tid(thread),
+			 thread__pid(parent), thread__tid(parent));
+		return 0;
+	}
+	/* But this one is new process, copy maps. */
+	return do_maps_clone ? maps__copy_from(thread__maps(thread), thread__maps(parent)) : 0;
+}
+
+int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp, bool do_maps_clone)
+{
+	if (thread__comm_set(parent)) {
+		const char *comm = thread__comm_str(parent);
+		int err;
+		if (!comm)
+			return -ENOMEM;
+		err = thread__set_comm(thread, comm, timestamp);
+		if (err)
+			return err;
+	}
+
+	thread__set_ppid(thread, thread__tid(parent));
+	return thread__clone_maps(thread, parent, do_maps_clone);
+}
+
+void thread__find_cpumode_addr_location(struct thread *thread, u64 addr,
+					bool symbols, struct addr_location *al)
+{
+	size_t i;
+	const u8 cpumodes[] = {
+		PERF_RECORD_MISC_USER,
+		PERF_RECORD_MISC_KERNEL,
+		PERF_RECORD_MISC_GUEST_USER,
+		PERF_RECORD_MISC_GUEST_KERNEL
+	};
+
+	for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
+		if (symbols)
+			thread__find_symbol(thread, cpumodes[i], addr, al);
+		else
+			thread__find_map(thread, cpumodes[i], addr, al);
+
+		if (al->map)
+			break;
+	}
+}
+
+static uint16_t read_proc_e_machine_for_pid(pid_t pid, uint32_t *e_flags, bool *is_big_endian)
+{
+	char path[6 /* "/proc/" */ + 11 /* max length of pid */ + 5 /* "/exe\0" */];
+	int fd;
+	uint16_t e_machine = EM_NONE;
+
+	snprintf(path, sizeof(path), "/proc/%d/exe", pid);
+	fd = open(path, O_RDONLY);
+	if (fd >= 0) {
+		e_machine = dso__read_e_machine_endian(/*optional_dso=*/NULL, fd, e_flags,
+						       is_big_endian);
+		close(fd);
+	}
+	return e_machine;
+}
+
+struct thread__e_machine_callback_args {
+	struct machine *machine;
+	uint32_t e_flags;
+	uint16_t e_machine;
+	bool is_big_endian;
+};
+
+static int thread__e_machine_callback(struct map *map, void *_args)
+{
+	struct thread__e_machine_callback_args *args = _args;
+	struct dso *dso = map__dso(map);
+
+	if (!dso)
+		return 0; // No dso, continue search.
+
+	args->e_machine =
+		dso__e_machine_endian(dso, args->machine, &args->e_flags, &args->is_big_endian);
+	return args->e_machine != EM_NONE ? 1 /* stop search */ : 0 /* continue search */;
+}
+
+uint16_t thread__e_machine_endian(struct thread *thread, struct machine *machine, uint32_t *e_flags,
+				  bool *is_big_endian)
+{
+	pid_t tid, pid;
+	uint16_t e_machine;
+	uint32_t local_e_flags = 0;
+	struct thread__e_machine_callback_args args;
+
+	if (!thread) {
+		if (is_big_endian) {
+			*is_big_endian = perf_arch_is_big_endian(
+				machine && machine->env ? perf_env__arch(machine->env) : NULL);
+		}
+		return perf_env__e_machine(machine ? machine->env : NULL, e_flags);
+	}
+
+	e_machine = RC_CHK_ACCESS(thread)->e_machine;
+	args.machine = machine;
+	args.e_flags = 0;
+	args.e_machine = EM_NONE;
+	args.is_big_endian = false;
+
+	if (e_machine != EM_NONE) {
+		if (e_flags)
+			*e_flags = thread__e_flags(thread);
+		if (is_big_endian)
+			*is_big_endian = thread__e_is_big_endian(thread);
+		return e_machine;
+	}
+
+	if (machine == NULL) {
+		struct maps *maps = thread__maps(thread);
+
+		machine = maps__machine(maps);
+		args.machine = machine;
+	}
+	tid = thread__tid(thread);
+	pid = thread__pid(thread);
+	if (pid != tid) {
+		struct thread *parent = machine__findnew_thread(machine, pid, pid);
+
+		if (parent) {
+			e_machine = thread__e_machine_endian(parent, machine, &local_e_flags,
+							     &args.is_big_endian);
+			thread__put(parent);
+			goto out;
+		}
+		/* Something went wrong, fallback. */
+	}
+	/* Reading on the PID thread. First try to find from the maps. */
+	maps__for_each_map(thread__maps(thread), thread__e_machine_callback, &args);
+
+	if (args.e_machine != EM_NONE) {
+		e_machine = args.e_machine;
+		local_e_flags = args.e_flags;
+	} else {
+		/* Maps failed, perhaps we're live with map events disabled. */
+		bool is_live = machine->machines == NULL;
+
+		if (!is_live) {
+			/* Check if the session has a data file. */
+			struct perf_session *session = container_of(machine->machines,
+								    struct perf_session,
+								    machines);
+
+			is_live = !!session->data;
+		}
+		/* Read from /proc/pid/exe if live. */
+		if (is_live) {
+			e_machine = read_proc_e_machine_for_pid(pid, &local_e_flags,
+								&args.is_big_endian);
+		} else if (machine && machine->env) {
+			/* Offline analysis: fallback to environment metadata. */
+			e_machine = perf_env__e_machine(machine->env, &local_e_flags);
+			args.is_big_endian = perf_arch_is_big_endian(perf_env__arch(machine->env));
+		}
+	}
+out:
+	if (e_machine != EM_NONE) {
+		thread__set_e_flags(thread, local_e_flags);
+		thread__set_e_is_big_endian(thread, args.is_big_endian);
+		thread__set_e_machine(thread, e_machine);
+		if (is_big_endian)
+			*is_big_endian = args.is_big_endian;
+	} else {
+		e_machine = EM_HOST;
+		local_e_flags = EF_HOST;
+		if (is_big_endian)
+			*is_big_endian = (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__);
+	}
+	if (e_flags)
+		*e_flags = local_e_flags;
+	return e_machine;
+}
+
+struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
+{
+	if (thread__pid(thread) == thread__tid(thread))
+		return thread__get(thread);
+
+	if (thread__pid(thread) == -1)
+		return NULL;
+
+	return machine__find_thread(machine, thread__pid(thread), thread__pid(thread));
+}
+
+int thread__memcpy(struct thread *thread, struct machine *machine,
+		   void *buf, u64 ip, int len, bool *is64bit)
+{
+	u8 cpumode = PERF_RECORD_MISC_USER;
+	struct addr_location al;
+	struct dso *dso;
+	long offset;
+
+	if (machine__kernel_ip(machine, ip))
+		cpumode = PERF_RECORD_MISC_KERNEL;
+
+	addr_location__init(&al);
+	if (!thread__find_map(thread, cpumode, ip, &al)) {
+		addr_location__exit(&al);
+		return -1;
+	}
+
+	dso = map__dso(al.map);
+
+	if (!dso || dso__data(dso)->status == DSO_DATA_STATUS_ERROR || map__load(al.map) < 0) {
+		addr_location__exit(&al);
+		return -1;
+	}
+
+	offset = map__map_ip(al.map, ip);
+	if (is64bit)
+		*is64bit = dso__is_64_bit(dso);
+
+	addr_location__exit(&al);
+
+	return dso__data_read_offset(dso, machine, offset, buf, len);
+}
+
+void thread__free_stitch_list(struct thread *thread)
+{
+	struct lbr_stitch *lbr_stitch = thread__lbr_stitch(thread);
+	struct stitch_list *pos, *tmp;
+
+	if (!lbr_stitch)
+		return;
+
+	list_for_each_entry_safe(pos, tmp, &lbr_stitch->lists, node) {
+		map_symbol__exit(&pos->cursor.ms);
+		list_del_init(&pos->node);
+		free(pos);
+	}
+
+	list_for_each_entry_safe(pos, tmp, &lbr_stitch->free_lists, node) {
+		list_del_init(&pos->node);
+		free(pos);
+	}
+
+	for (unsigned int i = 0 ; i < lbr_stitch->prev_lbr_cursor_size; i++)
+		map_symbol__exit(&lbr_stitch->prev_lbr_cursor[i].ms);
+
+	zfree(&lbr_stitch->prev_lbr_cursor);
+	free(thread__lbr_stitch(thread));
+	thread__set_lbr_stitch(thread, NULL);
+}