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, 252 insertions, 0 deletions

diff --git a/drivers/scsi/st.h b/drivers/scsi/st.h
new file mode 100644
index 000000000..0d7c4b8c2
--- /dev/null
+++ b/drivers/scsi/st.h
@@ -0,0 +1,252 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _ST_H
+#define _ST_H
+
+#include <linux/completion.h>
+#include <linux/mutex.h>
+#include <linux/kref.h>
+#include <scsi/scsi_cmnd.h>
+
+/* Descriptor for analyzed sense data */
+struct st_cmdstatus {
+	int midlevel_result;
+	struct scsi_sense_hdr sense_hdr;
+	int have_sense;
+	int residual;
+	u64 uremainder64;
+	u8 flags;
+	u8 remainder_valid;
+	u8 fixed_format;
+	u8 deferred;
+};
+
+struct scsi_tape;
+
+/* scsi tape command */
+struct st_request {
+	unsigned char cmd[MAX_COMMAND_SIZE];
+	unsigned char sense[SCSI_SENSE_BUFFERSIZE];
+	int result;
+	struct scsi_tape *stp;
+	struct completion *waiting;
+	struct bio *bio;
+};
+
+/* The tape buffer descriptor. */
+struct st_buffer {
+	unsigned char cleared;  /* internal buffer cleared after open? */
+	unsigned short do_dio;  /* direct i/o set up? */
+	int buffer_size;
+	int buffer_blocks;
+	int buffer_bytes;
+	int read_pointer;
+	int writing;
+	int syscall_result;
+	struct st_request *last_SRpnt;
+	struct st_cmdstatus cmdstat;
+	struct page **reserved_pages;
+	int reserved_page_order;
+	struct page **mapped_pages;
+	struct rq_map_data map_data;
+	unsigned char *b_data;
+	unsigned short use_sg;	/* zero or max number of s/g segments for this adapter */
+	unsigned short sg_segs;		/* number of segments in s/g list */
+	unsigned short frp_segs;	/* number of buffer segments */
+};
+
+/* The tape mode definition */
+struct st_modedef {
+	unsigned char defined;
+	unsigned char sysv;	/* SYS V semantics? */
+	unsigned char do_async_writes;
+	unsigned char do_buffer_writes;
+	unsigned char do_read_ahead;
+	unsigned char defaults_for_writes;
+	unsigned char default_compression;	/* 0 = don't touch, etc */
+	short default_density;	/* Forced density, -1 = no value */
+	int default_blksize;	/* Forced blocksize, -1 = no value */
+	struct scsi_tape *tape;
+	struct device *devs[2];  /* Auto-rewind and non-rewind devices */
+	struct cdev *cdevs[2];  /* Auto-rewind and non-rewind devices */
+};
+
+/* Number of modes can be changed by changing ST_NBR_MODE_BITS. The maximum
+   number of modes is 16 (ST_NBR_MODE_BITS 4) */
+#define ST_NBR_MODE_BITS 2
+#define ST_NBR_MODES (1 << ST_NBR_MODE_BITS)
+#define ST_MODE_SHIFT (7 - ST_NBR_MODE_BITS)
+#define ST_MODE_MASK ((ST_NBR_MODES - 1) << ST_MODE_SHIFT)
+
+#define ST_MAX_TAPES (1 << (20 - (ST_NBR_MODE_BITS + 1)))
+#define ST_MAX_TAPE_ENTRIES  (ST_MAX_TAPES << (ST_NBR_MODE_BITS + 1))
+
+/* The status related to each partition */
+struct st_partstat {
+	unsigned char rw;
+	unsigned char eof;
+	unsigned char at_sm;
+	unsigned char last_block_valid;
+	u32 last_block_visited;
+	int drv_block;		/* The block where the drive head is */
+	int drv_file;
+};
+
+/* Tape statistics */
+struct scsi_tape_stats {
+	atomic64_t read_byte_cnt;  /* bytes read */
+	atomic64_t write_byte_cnt; /* bytes written */
+	atomic64_t in_flight;      /* Number of I/Os in flight */
+	atomic64_t read_cnt;       /* Count of read requests */
+	atomic64_t write_cnt;      /* Count of write requests */
+	atomic64_t other_cnt;      /* Count of other requests either
+				    * implicit or from user space
+				    * ioctl. */
+	atomic64_t resid_cnt;      /* Count of resid_len > 0 */
+	atomic64_t tot_read_time;  /* ktime spent completing reads */
+	atomic64_t tot_write_time; /* ktime spent completing writes */
+	atomic64_t tot_io_time;    /* ktime spent doing any I/O */
+	ktime_t read_time;         /* holds ktime request was queued */
+	ktime_t write_time;        /* holds ktime request was queued */
+	ktime_t other_time;        /* holds ktime request was queued */
+	atomic_t last_read_size;   /* Number of bytes issued for last read */
+	atomic_t last_write_size;  /* Number of bytes issued for last write */
+};
+
+#define ST_NBR_PARTITIONS 4
+
+/* The tape drive descriptor */
+struct scsi_tape {
+	struct scsi_device *device;
+	struct mutex lock;	/* For serialization */
+	struct completion wait;	/* For SCSI commands */
+	struct st_buffer *buffer;
+	int index;
+
+	/* Drive characteristics */
+	unsigned char omit_blklims;
+	unsigned char do_auto_lock;
+	unsigned char can_bsr;
+	unsigned char can_partitions;
+	unsigned char two_fm;
+	unsigned char fast_mteom;
+	unsigned char immediate;
+	unsigned char scsi2_logical;
+	unsigned char default_drvbuffer;	/* 0xff = don't touch, value 3 bits */
+	unsigned char cln_mode;			/* 0 = none, otherwise sense byte nbr */
+	unsigned char cln_sense_value;
+	unsigned char cln_sense_mask;
+	unsigned char use_pf;			/* Set Page Format bit in all mode selects? */
+	unsigned char try_dio;			/* try direct i/o in general? */
+	unsigned char try_dio_now;		/* try direct i/o before next close? */
+	unsigned char c_algo;			/* compression algorithm */
+	unsigned char pos_unknown;			/* after reset position unknown */
+	unsigned char sili;			/* use SILI when reading in variable b mode */
+	unsigned char immediate_filemark;	/* write filemark immediately */
+	int tape_type;
+	int long_timeout;	/* timeout for commands known to take long time */
+
+	/* Mode characteristics */
+	struct st_modedef modes[ST_NBR_MODES];
+	int current_mode;
+
+	/* Status variables */
+	int partition;
+	int new_partition;
+	int nbr_partitions;	/* zero until partition support enabled */
+	struct st_partstat ps[ST_NBR_PARTITIONS];
+	unsigned char dirty;
+	unsigned char ready;
+	unsigned char write_prot;
+	unsigned char drv_write_prot;
+	unsigned char in_use;
+	unsigned char blksize_changed;
+	unsigned char density_changed;
+	unsigned char compression_changed;
+	unsigned char drv_buffer;
+	unsigned char density;
+	unsigned char changed_density;
+	unsigned char door_locked;
+	unsigned char autorew_dev;   /* auto-rewind device */
+	unsigned char rew_at_close;  /* rewind necessary at close */
+	unsigned char inited;
+	unsigned char cleaning_req;  /* cleaning requested? */
+	unsigned char first_tur;     /* first TEST UNIT READY */
+	int block_size;
+	int changed_blksize;
+	int min_block;
+	int max_block;
+	int recover_count;     /* From tape opening */
+	int recover_reg;       /* From last status call */
+
+	/* The saved values of midlevel counters */
+	unsigned int new_media_ctr;
+	unsigned int por_ctr;
+
+#if DEBUG
+	unsigned char write_pending;
+	int nbr_finished;
+	int nbr_waits;
+	int nbr_requests;
+	int nbr_dio;
+	int nbr_pages;
+	unsigned char last_cmnd[6];
+	unsigned char last_sense[16];
+#endif
+	char name[DISK_NAME_LEN];
+	struct kref     kref;
+	struct scsi_tape_stats *stats;
+};
+
+/* Bit masks for use_pf */
+#define USE_PF      1
+#define PF_TESTED   2
+
+/* Values of eof */
+#define	ST_NOEOF	0
+#define ST_FM_HIT       1
+#define ST_FM           2
+#define ST_EOM_OK       3
+#define ST_EOM_ERROR	4
+#define	ST_EOD_1        5
+#define ST_EOD_2        6
+#define ST_EOD		7
+/* EOD hit while reading => ST_EOD_1 => return zero => ST_EOD_2 =>
+   return zero => ST_EOD, return ENOSPC */
+/* When writing: ST_EOM_OK == early warning found, write OK
+		 ST_EOD_1  == allow trying new write after early warning
+		 ST_EOM_ERROR == early warning found, not able to write all */
+
+/* Values of rw */
+#define	ST_IDLE		0
+#define	ST_READING	1
+#define	ST_WRITING	2
+
+/* Values of ready state */
+#define ST_READY	0
+#define ST_NOT_READY	1
+#define ST_NO_TAPE	2
+
+/* Values for door lock state */
+#define ST_UNLOCKED	0
+#define ST_LOCKED_EXPLICIT 1
+#define ST_LOCKED_AUTO  2
+#define ST_LOCK_FAILS   3
+
+/* Positioning SCSI-commands for Tandberg, etc. drives */
+#define	QFA_REQUEST_BLOCK	0x02
+#define	QFA_SEEK_BLOCK		0x0c
+
+/* Setting the binary options */
+#define ST_DONT_TOUCH  0
+#define ST_NO          1
+#define ST_YES         2
+
+#define EXTENDED_SENSE_START  18
+
+/* Masks for some conditions in the sense data */
+#define SENSE_FMK   0x80
+#define SENSE_EOM   0x40
+#define SENSE_ILI   0x20
+
+#endif