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, 614 insertions, 0 deletions

diff --git a/fs/lockd/clntxdr.c b/fs/lockd/clntxdr.c
new file mode 100644
index 000000000..3789ecb0b
--- /dev/null
+++ b/fs/lockd/clntxdr.c
@@ -0,0 +1,614 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * linux/fs/lockd/clntxdr.c
+ *
+ * XDR functions to encode/decode NLM version 1 and 3 RPC
+ * arguments and results. NLM version 2 is not specified
+ * by a standard, thus it is not implemented.
+ *
+ * NLM client-side only.
+ *
+ * Copyright (C) 2010, Oracle.  All rights reserved.
+ */
+
+#include <linux/types.h>
+#include <linux/sunrpc/xdr.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/stats.h>
+
+#include "lockd.h"
+
+#include <uapi/linux/nfs2.h>
+
+#define NLMDBG_FACILITY		NLMDBG_XDR
+
+#if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
+#  error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
+#endif
+
+/*
+ * Declare the space requirements for NLM arguments and replies as
+ * number of 32bit-words
+ */
+#define NLM_cookie_sz		(1+(NLM_MAXCOOKIELEN>>2))
+#define NLM_caller_sz		(1+(NLMCLNT_OHSIZE>>2))
+#define NLM_owner_sz		(1+(NLMCLNT_OHSIZE>>2))
+#define NLM_fhandle_sz		(1+(NFS2_FHSIZE>>2))
+#define NLM_lock_sz		(3+NLM_caller_sz+NLM_owner_sz+NLM_fhandle_sz)
+#define NLM_holder_sz		(4+NLM_owner_sz)
+
+#define NLM_testargs_sz		(NLM_cookie_sz+1+NLM_lock_sz)
+#define NLM_lockargs_sz		(NLM_cookie_sz+4+NLM_lock_sz)
+#define NLM_cancargs_sz		(NLM_cookie_sz+2+NLM_lock_sz)
+#define NLM_unlockargs_sz	(NLM_cookie_sz+NLM_lock_sz)
+
+#define NLM_testres_sz		(NLM_cookie_sz+1+NLM_holder_sz)
+#define NLM_res_sz		(NLM_cookie_sz+1)
+#define NLM_norep_sz		(0)
+
+
+static s32 loff_t_to_s32(loff_t offset)
+{
+	s32 res;
+
+	if (offset >= NLM_OFFSET_MAX)
+		res = NLM_OFFSET_MAX;
+	else if (offset <= -NLM_OFFSET_MAX)
+		res = -NLM_OFFSET_MAX;
+	else
+		res = offset;
+	return res;
+}
+
+static void nlm_compute_offsets(const struct lockd_lock *lock,
+				u32 *l_offset, u32 *l_len)
+{
+	const struct file_lock *fl = &lock->fl;
+
+	*l_offset = loff_t_to_s32(fl->fl_start);
+	if (fl->fl_end == OFFSET_MAX)
+		*l_len = 0;
+	else
+		*l_len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
+}
+
+/*
+ * Encode/decode NLMv3 basic data types
+ *
+ * Basic NLMv3 data types are not defined in an IETF standards
+ * document.  X/Open has a description of these data types that
+ * is useful.  See Chapter 10 of "Protocols for Interworking:
+ * XNFS, Version 3W".
+ *
+ * Not all basic data types have their own encoding and decoding
+ * functions.  For run-time efficiency, some data types are encoded
+ * or decoded inline.
+ */
+
+static void encode_bool(struct xdr_stream *xdr, const int value)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = value ? xdr_one : xdr_zero;
+}
+
+static void encode_int32(struct xdr_stream *xdr, const s32 value)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4);
+	*p = cpu_to_be32(value);
+}
+
+/*
+ *	typedef opaque netobj<MAXNETOBJ_SZ>
+ */
+static void encode_netobj(struct xdr_stream *xdr,
+			  const u8 *data, const unsigned int length)
+{
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 + length);
+	xdr_encode_opaque(p, data, length);
+}
+
+static int decode_netobj(struct xdr_stream *xdr,
+			 struct xdr_netobj *obj)
+{
+	ssize_t ret;
+
+	ret = xdr_stream_decode_opaque_inline(xdr, (void *)&obj->data,
+			XDR_MAX_NETOBJ);
+	if (unlikely(ret < 0))
+		return -EIO;
+	obj->len = ret;
+	return 0;
+}
+
+/*
+ *	netobj cookie;
+ */
+static void encode_cookie(struct xdr_stream *xdr,
+			  const struct lockd_cookie *cookie)
+{
+	encode_netobj(xdr, (u8 *)&cookie->data, cookie->len);
+}
+
+static int decode_cookie(struct xdr_stream *xdr,
+			 struct lockd_cookie *cookie)
+{
+	u32 length;
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	length = be32_to_cpup(p++);
+	/* apparently HPUX can return empty cookies */
+	if (length == 0)
+		goto out_hpux;
+	if (length > NLM_MAXCOOKIELEN)
+		goto out_size;
+	p = xdr_inline_decode(xdr, length);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	cookie->len = length;
+	memcpy(cookie->data, p, length);
+	return 0;
+out_hpux:
+	cookie->len = 4;
+	memset(cookie->data, 0, 4);
+	return 0;
+out_size:
+	dprintk("NFS: returned cookie was too long: %u\n", length);
+	return -EIO;
+out_overflow:
+	return -EIO;
+}
+
+/*
+ *	netobj fh;
+ */
+static void encode_fh(struct xdr_stream *xdr, const struct nfs_fh *fh)
+{
+	encode_netobj(xdr, (u8 *)&fh->data, NFS2_FHSIZE);
+}
+
+/*
+ *	enum nlm_stats {
+ *		LCK_GRANTED = 0,
+ *		LCK_DENIED = 1,
+ *		LCK_DENIED_NOLOCKS = 2,
+ *		LCK_BLOCKED = 3,
+ *		LCK_DENIED_GRACE_PERIOD = 4
+ *	};
+ *
+ *
+ *	struct nlm_stat {
+ *		nlm_stats stat;
+ *	};
+ *
+ * NB: we don't swap bytes for the NLM status values.  The upper
+ * layers deal directly with the status value in network byte
+ * order.
+ */
+
+static void encode_nlm_stat(struct xdr_stream *xdr,
+			    const __be32 stat)
+{
+	__be32 *p;
+
+	WARN_ON_ONCE(be32_to_cpu(stat) > NLM_LCK_DENIED_GRACE_PERIOD);
+	p = xdr_reserve_space(xdr, 4);
+	*p = stat;
+}
+
+static int decode_nlm_stat(struct xdr_stream *xdr,
+			   __be32 *stat)
+{
+	__be32 *p;
+
+	p = xdr_inline_decode(xdr, 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	if (unlikely(ntohl(*p) > ntohl(nlm_lck_denied_grace_period)))
+		goto out_enum;
+	*stat = *p;
+	return 0;
+out_enum:
+	dprintk("%s: server returned invalid nlm_stats value: %u\n",
+		__func__, be32_to_cpup(p));
+	return -EIO;
+out_overflow:
+	return -EIO;
+}
+
+/*
+ *	struct nlm_holder {
+ *		bool exclusive;
+ *		int uppid;
+ *		netobj oh;
+ *		unsigned l_offset;
+ *		unsigned l_len;
+ *	};
+ */
+static void encode_nlm_holder(struct xdr_stream *xdr,
+			      const struct lockd_res *result)
+{
+	const struct lockd_lock *lock = &result->lock;
+	u32 l_offset, l_len;
+	__be32 *p;
+
+	encode_bool(xdr, lock->fl.c.flc_type == F_RDLCK);
+	encode_int32(xdr, lock->svid);
+	encode_netobj(xdr, lock->oh.data, lock->oh.len);
+
+	p = xdr_reserve_space(xdr, 4 + 4);
+	nlm_compute_offsets(lock, &l_offset, &l_len);
+	*p++ = cpu_to_be32(l_offset);
+	*p   = cpu_to_be32(l_len);
+}
+
+static int decode_nlm_holder(struct xdr_stream *xdr, struct lockd_res *result)
+{
+	struct lockd_lock *lock = &result->lock;
+	struct file_lock *fl = &lock->fl;
+	u32 exclusive, l_offset, l_len;
+	int error;
+	__be32 *p;
+	s32 end;
+
+	memset(lock, 0, sizeof(*lock));
+	locks_init_lock(fl);
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+	exclusive = be32_to_cpup(p++);
+	lock->svid = be32_to_cpup(p);
+	fl->c.flc_pid = (pid_t)lock->svid;
+
+	error = decode_netobj(xdr, &lock->oh);
+	if (unlikely(error))
+		goto out;
+
+	p = xdr_inline_decode(xdr, 4 + 4);
+	if (unlikely(p == NULL))
+		goto out_overflow;
+
+	fl->c.flc_flags = FL_POSIX;
+	fl->c.flc_type  = exclusive != 0 ? F_WRLCK : F_RDLCK;
+	l_offset = be32_to_cpup(p++);
+	l_len = be32_to_cpup(p);
+	end = l_offset + l_len - 1;
+
+	fl->fl_start = (loff_t)l_offset;
+	if (l_len == 0 || end < 0)
+		fl->fl_end = OFFSET_MAX;
+	else
+		fl->fl_end = (loff_t)end;
+	error = 0;
+out:
+	return error;
+out_overflow:
+	return -EIO;
+}
+
+/*
+ *	string caller_name<LM_MAXSTRLEN>;
+ */
+static void encode_caller_name(struct xdr_stream *xdr, const char *name)
+{
+	/* NB: client-side does not set lock->len */
+	u32 length = strlen(name);
+	__be32 *p;
+
+	p = xdr_reserve_space(xdr, 4 + length);
+	xdr_encode_opaque(p, name, length);
+}
+
+/*
+ *	struct nlm_lock {
+ *		string caller_name<LM_MAXSTRLEN>;
+ *		netobj fh;
+ *		netobj oh;
+ *		int uppid;
+ *		unsigned l_offset;
+ *		unsigned l_len;
+ *	};
+ */
+static void encode_nlm_lock(struct xdr_stream *xdr,
+			    const struct lockd_lock *lock)
+{
+	u32 l_offset, l_len;
+	__be32 *p;
+
+	encode_caller_name(xdr, lock->caller);
+	encode_fh(xdr, &lock->fh);
+	encode_netobj(xdr, lock->oh.data, lock->oh.len);
+
+	p = xdr_reserve_space(xdr, 4 + 4 + 4);
+	*p++ = cpu_to_be32(lock->svid);
+
+	nlm_compute_offsets(lock, &l_offset, &l_len);
+	*p++ = cpu_to_be32(l_offset);
+	*p   = cpu_to_be32(l_len);
+}
+
+
+/*
+ * NLMv3 XDR encode functions
+ *
+ * NLMv3 argument types are defined in Chapter 10 of The Open Group's
+ * "Protocols for Interworking: XNFS, Version 3W".
+ */
+
+/*
+ *	struct nlm_testargs {
+ *		netobj cookie;
+ *		bool exclusive;
+ *		struct nlm_lock alock;
+ *	};
+ */
+static void nlm_xdr_enc_testargs(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct lockd_args *args = data;
+	const struct lockd_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_bool(xdr, lock->fl.c.flc_type == F_WRLCK);
+	encode_nlm_lock(xdr, lock);
+}
+
+/*
+ *	struct nlm_lockargs {
+ *		netobj cookie;
+ *		bool block;
+ *		bool exclusive;
+ *		struct nlm_lock alock;
+ *		bool reclaim;
+ *		int state;
+ *	};
+ */
+static void nlm_xdr_enc_lockargs(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct lockd_args *args = data;
+	const struct lockd_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_bool(xdr, args->block);
+	encode_bool(xdr, lock->fl.c.flc_type == F_WRLCK);
+	encode_nlm_lock(xdr, lock);
+	encode_bool(xdr, args->reclaim);
+	encode_int32(xdr, args->state);
+}
+
+/*
+ *	struct nlm_cancargs {
+ *		netobj cookie;
+ *		bool block;
+ *		bool exclusive;
+ *		struct nlm_lock alock;
+ *	};
+ */
+static void nlm_xdr_enc_cancargs(struct rpc_rqst *req,
+				 struct xdr_stream *xdr,
+				 const void *data)
+{
+	const struct lockd_args *args = data;
+	const struct lockd_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_bool(xdr, args->block);
+	encode_bool(xdr, lock->fl.c.flc_type == F_WRLCK);
+	encode_nlm_lock(xdr, lock);
+}
+
+/*
+ *	struct nlm_unlockargs {
+ *		netobj cookie;
+ *		struct nlm_lock alock;
+ *	};
+ */
+static void nlm_xdr_enc_unlockargs(struct rpc_rqst *req,
+				   struct xdr_stream *xdr,
+				   const void *data)
+{
+	const struct lockd_args *args = data;
+	const struct lockd_lock *lock = &args->lock;
+
+	encode_cookie(xdr, &args->cookie);
+	encode_nlm_lock(xdr, lock);
+}
+
+/*
+ *	struct nlm_res {
+ *		netobj cookie;
+ *		nlm_stat stat;
+ *	};
+ */
+static void nlm_xdr_enc_res(struct rpc_rqst *req,
+			    struct xdr_stream *xdr,
+			    const void *data)
+{
+	const struct lockd_res *result = data;
+
+	encode_cookie(xdr, &result->cookie);
+	encode_nlm_stat(xdr, result->status);
+}
+
+/*
+ *	union nlm_testrply switch (nlm_stats stat) {
+ *	case LCK_DENIED:
+ *		struct nlm_holder holder;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	struct nlm_testres {
+ *		netobj cookie;
+ *		nlm_testrply test_stat;
+ *	};
+ */
+static void encode_nlm_testrply(struct xdr_stream *xdr,
+				const struct lockd_res *result)
+{
+	if (result->status == nlm_lck_denied)
+		encode_nlm_holder(xdr, result);
+}
+
+static void nlm_xdr_enc_testres(struct rpc_rqst *req,
+				struct xdr_stream *xdr,
+				const void *data)
+{
+	const struct lockd_res *result = data;
+
+	encode_cookie(xdr, &result->cookie);
+	encode_nlm_stat(xdr, result->status);
+	encode_nlm_testrply(xdr, result);
+}
+
+
+/*
+ * NLMv3 XDR decode functions
+ *
+ * NLMv3 result types are defined in Chapter 10 of The Open Group's
+ * "Protocols for Interworking: XNFS, Version 3W".
+ */
+
+/*
+ *	union nlm_testrply switch (nlm_stats stat) {
+ *	case LCK_DENIED:
+ *		struct nlm_holder holder;
+ *	default:
+ *		void;
+ *	};
+ *
+ *	struct nlm_testres {
+ *		netobj cookie;
+ *		nlm_testrply test_stat;
+ *	};
+ */
+static int decode_nlm_testrply(struct xdr_stream *xdr,
+			       struct lockd_res *result)
+{
+	int error;
+
+	error = decode_nlm_stat(xdr, &result->status);
+	if (unlikely(error))
+		goto out;
+	if (result->status == nlm_lck_denied)
+		error = decode_nlm_holder(xdr, result);
+out:
+	return error;
+}
+
+static int nlm_xdr_dec_testres(struct rpc_rqst *req,
+			       struct xdr_stream *xdr,
+			       void *data)
+{
+	struct lockd_res *result = data;
+	int error;
+
+	error = decode_cookie(xdr, &result->cookie);
+	if (unlikely(error))
+		goto out;
+	error = decode_nlm_testrply(xdr, result);
+out:
+	return error;
+}
+
+/*
+ *	struct nlm_res {
+ *		netobj cookie;
+ *		nlm_stat stat;
+ *	};
+ */
+static int nlm_xdr_dec_res(struct rpc_rqst *req,
+			   struct xdr_stream *xdr,
+			   void *data)
+{
+	struct lockd_res *result = data;
+	int error;
+
+	error = decode_cookie(xdr, &result->cookie);
+	if (unlikely(error))
+		goto out;
+	error = decode_nlm_stat(xdr, &result->status);
+out:
+	return error;
+}
+
+
+/*
+ * For NLM, a void procedure really returns nothing
+ */
+#define nlm_xdr_dec_norep	NULL
+
+#define PROC(proc, argtype, restype)	\
+[NLMPROC_##proc] = {							\
+	.p_proc      = NLMPROC_##proc,					\
+	.p_encode    = nlm_xdr_enc_##argtype,		\
+	.p_decode    = nlm_xdr_dec_##restype,				\
+	.p_arglen    = NLM_##argtype##_sz,				\
+	.p_replen    = NLM_##restype##_sz,				\
+	.p_statidx   = NLMPROC_##proc,					\
+	.p_name      = #proc,						\
+	}
+
+static const struct rpc_procinfo nlm_procedures[] = {
+	PROC(TEST,		testargs,	testres),
+	PROC(LOCK,		lockargs,	res),
+	PROC(CANCEL,		cancargs,	res),
+	PROC(UNLOCK,		unlockargs,	res),
+	PROC(GRANTED,		testargs,	res),
+	PROC(TEST_MSG,		testargs,	norep),
+	PROC(LOCK_MSG,		lockargs,	norep),
+	PROC(CANCEL_MSG,	cancargs,	norep),
+	PROC(UNLOCK_MSG,	unlockargs,	norep),
+	PROC(GRANTED_MSG,	testargs,	norep),
+	PROC(TEST_RES,		testres,	norep),
+	PROC(LOCK_RES,		res,		norep),
+	PROC(CANCEL_RES,	res,		norep),
+	PROC(UNLOCK_RES,	res,		norep),
+	PROC(GRANTED_RES,	res,		norep),
+};
+
+static unsigned int nlm_version1_counts[ARRAY_SIZE(nlm_procedures)];
+static const struct rpc_version	nlm_version1 = {
+	.number		= 1,
+	.nrprocs	= ARRAY_SIZE(nlm_procedures),
+	.procs		= nlm_procedures,
+	.counts		= nlm_version1_counts,
+};
+
+static unsigned int nlm_version3_counts[ARRAY_SIZE(nlm_procedures)];
+static const struct rpc_version	nlm_version3 = {
+	.number		= 3,
+	.nrprocs	= ARRAY_SIZE(nlm_procedures),
+	.procs		= nlm_procedures,
+	.counts		= nlm_version3_counts,
+};
+
+static const struct rpc_version	*nlm_versions[] = {
+	[1] = &nlm_version1,
+	[3] = &nlm_version3,
+#ifdef CONFIG_LOCKD_V4
+	[4] = &nlm_version4,
+#endif
+};
+
+static struct rpc_stat		nlm_rpc_stats;
+
+const struct rpc_program	nlm_program = {
+	.name		= "lockd",
+	.number		= NLM_PROGRAM,
+	.nrvers		= ARRAY_SIZE(nlm_versions),
+	.version	= nlm_versions,
+	.stats		= &nlm_rpc_stats,
+};