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, 139 insertions, 0 deletions

diff --git a/fs/nfsd/export.h b/fs/nfsd/export.h
new file mode 100644
index 000000000..d2b09cd76
--- /dev/null
+++ b/fs/nfsd/export.h
@@ -0,0 +1,139 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
+ */
+#ifndef NFSD_EXPORT_H
+#define NFSD_EXPORT_H
+
+#include <linux/sunrpc/cache.h>
+#include <linux/percpu_counter.h>
+#include <uapi/linux/nfsd/export.h>
+#include <linux/nfs4.h>
+
+struct knfsd_fh;
+struct svc_fh;
+struct svc_rqst;
+
+/*
+ * FS Locations
+ */
+
+#define MAX_FS_LOCATIONS	128
+
+struct nfsd4_fs_location {
+	char *hosts; /* colon separated list of hosts */
+	char *path;  /* slash separated list of path components */
+};
+
+struct nfsd4_fs_locations {
+	uint32_t locations_count;
+	struct nfsd4_fs_location *locations;
+/* If we're not actually serving this data ourselves (only providing a
+ * list of replicas that do serve it) then we set "migrated": */
+	int migrated;
+};
+
+/*
+ * We keep an array of pseudoflavors with the export, in order from most
+ * to least preferred.  For the foreseeable future, we don't expect more
+ * than the eight pseudoflavors null, unix, krb5, krb5i, krb5p, skpm3,
+ * spkm3i, and spkm3p (and using all 8 at once should be rare).
+ */
+#define MAX_SECINFO_LIST	8
+#define EX_UUID_LEN		16
+
+struct exp_flavor_info {
+	u32	pseudoflavor;
+	u32	flags;
+};
+
+/* Per-export stats */
+enum {
+	EXP_STATS_FH_STALE,
+	EXP_STATS_IO_READ,
+	EXP_STATS_IO_WRITE,
+	EXP_STATS_COUNTERS_NUM
+};
+
+struct export_stats {
+	time64_t		start_time;
+	struct percpu_counter	counter[EXP_STATS_COUNTERS_NUM];
+};
+
+struct svc_export {
+	struct cache_head	h;
+	struct auth_domain *	ex_client;
+	int			ex_flags;
+	int			ex_fsid;
+	struct path		ex_path;
+	kuid_t			ex_anon_uid;
+	kgid_t			ex_anon_gid;
+	unsigned char *		ex_uuid; /* 16 byte fsid */
+	struct nfsd4_fs_locations ex_fslocs;
+	uint32_t		ex_nflavors;
+	struct exp_flavor_info	ex_flavors[MAX_SECINFO_LIST];
+	u32			ex_layout_types;
+	struct nfsd4_deviceid_map *ex_devid_map;
+	struct cache_detail	*cd;
+	struct rcu_head		ex_rcu;
+	unsigned long		ex_xprtsec_modes;
+	struct export_stats	*ex_stats;
+};
+
+/* an "export key" (expkey) maps a filehandlefragement to an
+ * svc_export for a given client.  There can be several per export,
+ * for the different fsid types.
+ */
+struct svc_expkey {
+	struct cache_head	h;
+
+	struct auth_domain *	ek_client;
+	u8			ek_fsidtype;
+	u32			ek_fsid[6];
+
+	struct path		ek_path;
+	struct rcu_head		ek_rcu;
+};
+
+#define EX_ISSYNC(exp)		(!((exp)->ex_flags & NFSEXP_ASYNC))
+#define EX_NOHIDE(exp)		((exp)->ex_flags & NFSEXP_NOHIDE)
+#define EX_WGATHER(exp)		((exp)->ex_flags & NFSEXP_GATHERED_WRITES)
+
+struct svc_cred;
+int nfsexp_flags(struct svc_cred *cred, struct svc_export *exp);
+__be32 check_xprtsec_policy(struct svc_export *exp, struct svc_rqst *rqstp);
+__be32 check_security_flavor(struct svc_export *exp, struct svc_rqst *rqstp,
+			     bool may_bypass_gss);
+__be32 check_nfsd_access(struct svc_export *exp, struct svc_rqst *rqstp,
+			 bool may_bypass_gss);
+
+/*
+ * Function declarations
+ */
+int			nfsd_export_init(struct net *);
+void			nfsd_export_shutdown(struct net *);
+void			nfsd_export_flush(struct net *);
+struct svc_export *	rqst_exp_get_by_name(struct svc_rqst *,
+					     const struct path *);
+struct svc_export *	rqst_exp_parent(struct svc_rqst *,
+					struct path *);
+struct svc_export *	rqst_find_fsidzero_export(struct svc_rqst *);
+int			exp_rootfh(struct net *, struct auth_domain *,
+					char *path, struct knfsd_fh *, int maxsize);
+__be32			exp_pseudoroot(struct svc_rqst *, struct svc_fh *);
+
+static inline void exp_put(struct svc_export *exp)
+{
+	cache_put(&exp->h, exp->cd);
+}
+
+static inline struct svc_export *exp_get(struct svc_export *exp)
+{
+	cache_get(&exp->h);
+	return exp;
+}
+struct svc_export *rqst_exp_find(struct cache_req *reqp, struct net *net,
+				 struct auth_domain *cl, struct auth_domain *gsscl,
+				 int fsid_type, u32 *fsidv);
+
+#endif /* NFSD_EXPORT_H */