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, 166 insertions, 0 deletions

diff --git a/drivers/s390/cio/css.h b/drivers/s390/cio/css.h
new file mode 100644
index 000000000..a65a27dc5
--- /dev/null
+++ b/drivers/s390/cio/css.h
@@ -0,0 +1,166 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _CSS_H
+#define _CSS_H
+
+#include <linux/mutex.h>
+#include <linux/wait.h>
+#include <linux/workqueue.h>
+#include <linux/device.h>
+#include <linux/types.h>
+
+#include <asm/cio.h>
+#include <asm/chpid.h>
+#include <asm/schid.h>
+
+#include "cio.h"
+
+/*
+ * path grouping stuff
+ */
+#define SPID_FUNC_SINGLE_PATH	   0x00
+#define SPID_FUNC_MULTI_PATH	   0x80
+#define SPID_FUNC_ESTABLISH	   0x00
+#define SPID_FUNC_RESIGN	   0x40
+#define SPID_FUNC_DISBAND	   0x20
+
+#define SNID_STATE1_RESET	   0
+#define SNID_STATE1_UNGROUPED	   2
+#define SNID_STATE1_GROUPED	   3
+
+#define SNID_STATE2_NOT_RESVD	   0
+#define SNID_STATE2_RESVD_ELSE	   2
+#define SNID_STATE2_RESVD_SELF	   3
+
+#define SNID_STATE3_MULTI_PATH	   1
+#define SNID_STATE3_SINGLE_PATH	   0
+
+/*
+ * Miscellaneous constants
+ */
+
+#define CSS_NUM_CUB_PAGES		2
+#define CSS_CUES_PER_PAGE		128
+#define CSS_NUM_ECUB_PAGES		4
+#define CSS_ECUES_PER_PAGE		64
+
+/*
+ * Conditions used to specify which subchannels need evaluation
+ */
+enum css_eval_cond {
+	CSS_EVAL_NO_PATH,		/* Subchannels with no operational paths */
+	CSS_EVAL_NOT_ONLINE	/* sch without an online-device */
+};
+
+struct path_state {
+	__u8  state1 : 2;	/* path state value 1 */
+	__u8  state2 : 2;	/* path state value 2 */
+	__u8  state3 : 1;	/* path state value 3 */
+	__u8  resvd  : 3;	/* reserved */
+} __attribute__ ((packed));
+
+struct extended_cssid {
+	u8 version;
+	u8 cssid;
+} __attribute__ ((packed));
+
+struct pgid {
+	union {
+		__u8 fc;   	/* SPID function code */
+		struct path_state ps;	/* SNID path state */
+	} __attribute__ ((packed)) inf;
+	union {
+		__u32 cpu_addr	: 16;	/* CPU address */
+		struct extended_cssid ext_cssid;
+	} __attribute__ ((packed)) pgid_high;
+	__u32 cpu_id	: 24;	/* CPU identification */
+	__u32 cpu_model : 16;	/* CPU model */
+	__u32 tod_high;		/* high word TOD clock */
+} __attribute__ ((packed));
+
+struct subchannel;
+struct chp_link;
+/**
+ * struct css_driver - device driver for subchannels
+ * @subchannel_type: subchannel type supported by this driver
+ * @drv: embedded device driver structure
+ * @irq: called on interrupts
+ * @chp_event: called for events affecting a channel path
+ * @sch_event: called for events affecting the subchannel
+ * @probe: function called on probe
+ * @remove: function called on remove
+ * @shutdown: called at device shutdown
+ * @settle: wait for asynchronous work to finish
+ */
+struct css_driver {
+	struct css_device_id *subchannel_type;
+	struct device_driver drv;
+	void (*irq)(struct subchannel *);
+	int (*chp_event)(struct subchannel *, struct chp_link *, int);
+	int (*sch_event)(struct subchannel *, int);
+	int (*probe)(struct subchannel *);
+	void (*remove)(struct subchannel *);
+	void (*shutdown)(struct subchannel *);
+	int (*settle)(void);
+};
+
+#define to_cssdriver(n) container_of_const(n, struct css_driver, drv)
+
+extern int css_driver_register(struct css_driver *);
+extern void css_driver_unregister(struct css_driver *);
+
+extern void css_sch_device_unregister(struct subchannel *);
+extern int css_register_subchannel(struct subchannel *);
+extern struct subchannel *css_alloc_subchannel(struct subchannel_id,
+					       struct schib *schib);
+extern struct subchannel *get_subchannel_by_schid(struct subchannel_id);
+extern int css_init_done;
+extern int max_ssid;
+int for_each_subchannel_staged(int (*fn_known)(struct subchannel *, void *),
+			       int (*fn_unknown)(struct subchannel_id,
+			       void *), void *data);
+extern int for_each_subchannel(int(*fn)(struct subchannel_id, void *), void *);
+void css_update_ssd_info(struct subchannel *sch);
+
+struct channel_subsystem {
+	u8 cssid;
+	u8 iid;
+	bool id_valid; /* cssid,iid */
+	struct channel_path *chps[__MAX_CHPID + 1];
+	struct device device;
+	struct pgid global_pgid;
+	struct mutex mutex;
+	/* channel measurement related */
+	int cm_enabled;
+	void *cub[CSS_NUM_CUB_PAGES];
+	void *ecub[CSS_NUM_ECUB_PAGES];
+	/* for orphaned ccw devices */
+	struct subchannel *pseudo_subchannel;
+};
+#define to_css(dev) container_of(dev, struct channel_subsystem, device)
+
+extern struct channel_subsystem *channel_subsystems[];
+
+/* Dummy helper which needs to change once we support more than one css. */
+static inline struct channel_subsystem *css_by_id(u8 cssid)
+{
+	return channel_subsystems[0];
+}
+
+/* Dummy iterator which needs to change once we support more than one css. */
+#define for_each_css(css)						\
+	for ((css) = channel_subsystems[0]; (css); (css) = NULL)
+
+/* Helper functions to build lists for the slow path. */
+void css_schedule_eval(struct subchannel_id schid);
+void css_schedule_eval_all(void);
+void css_schedule_eval_cond(enum css_eval_cond, unsigned long delay);
+int css_complete_work(void);
+
+int sch_is_pseudo_sch(struct subchannel *);
+struct schib;
+int css_sch_is_valid(struct schib *);
+
+extern struct workqueue_struct *cio_work_q;
+void css_wait_for_slow_path(void);
+void css_sched_sch_todo(struct subchannel *sch, enum sch_todo todo);
+#endif