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, 426 insertions, 0 deletions

diff --git a/fs/jffs2/compr.c b/fs/jffs2/compr.c
new file mode 100644
index 000000000..764f19dec
--- /dev/null
+++ b/fs/jffs2/compr.c
@@ -0,0 +1,426 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
+ * Copyright © 2004 Ferenc Havasi <havasi@inf.u-szeged.hu>,
+ *		    University of Szeged, Hungary
+ *
+ * Created by Arjan van de Ven <arjan@infradead.org>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include "compr.h"
+
+static DEFINE_SPINLOCK(jffs2_compressor_list_lock);
+
+/* Available compressors are on this list */
+static LIST_HEAD(jffs2_compressor_list);
+
+/* Actual compression mode */
+static int jffs2_compression_mode = JFFS2_COMPR_MODE_PRIORITY;
+
+/* Statistics for blocks stored without compression */
+static uint32_t none_stat_compr_blocks=0,none_stat_decompr_blocks=0,none_stat_compr_size=0;
+
+
+/*
+ * Return 1 to use this compression
+ */
+static int jffs2_is_best_compression(struct jffs2_compressor *this,
+		struct jffs2_compressor *best, uint32_t size, uint32_t bestsize)
+{
+	switch (jffs2_compression_mode) {
+	case JFFS2_COMPR_MODE_SIZE:
+		if (bestsize > size)
+			return 1;
+		return 0;
+	case JFFS2_COMPR_MODE_FAVOURLZO:
+		if ((this->compr == JFFS2_COMPR_LZO) && (bestsize > size))
+			return 1;
+		if ((best->compr != JFFS2_COMPR_LZO) && (bestsize > size))
+			return 1;
+		if ((this->compr == JFFS2_COMPR_LZO) && (bestsize > (size * FAVOUR_LZO_PERCENT / 100)))
+			return 1;
+		if ((bestsize * FAVOUR_LZO_PERCENT / 100) > size)
+			return 1;
+
+		return 0;
+	}
+	/* Shouldn't happen */
+	return 0;
+}
+
+/*
+ * jffs2_selected_compress:
+ * @compr: Explicit compression type to use (ie, JFFS2_COMPR_ZLIB).
+ *	If 0, just take the first available compression mode.
+ * @data_in: Pointer to uncompressed data
+ * @cpage_out: Pointer to returned pointer to buffer for compressed data
+ * @datalen: On entry, holds the amount of data available for compression.
+ *	On exit, expected to hold the amount of data actually compressed.
+ * @cdatalen: On entry, holds the amount of space available for compressed
+ *	data. On exit, expected to hold the actual size of the compressed
+ *	data.
+ *
+ * Returns: the compression type used.  Zero is used to show that the data
+ * could not be compressed; probably because we couldn't find the requested
+ * compression mode.
+ */
+static int jffs2_selected_compress(u8 compr, unsigned char *data_in,
+		unsigned char **cpage_out, u32 *datalen, u32 *cdatalen)
+{
+	struct jffs2_compressor *this;
+	int err, ret = JFFS2_COMPR_NONE;
+	uint32_t orig_slen, orig_dlen;
+	char *output_buf;
+
+	output_buf = kmalloc(*cdatalen, GFP_KERNEL);
+	if (!output_buf) {
+		pr_warn("No memory for compressor allocation. Compression failed.\n");
+		return ret;
+	}
+	orig_slen = *datalen;
+	orig_dlen = *cdatalen;
+	spin_lock(&jffs2_compressor_list_lock);
+	list_for_each_entry(this, &jffs2_compressor_list, list) {
+		/* Skip decompress-only and disabled modules */
+		if (!this->compress || this->disabled)
+			continue;
+
+		/* Skip if not the desired compression type */
+		if (compr && (compr != this->compr))
+			continue;
+
+		/*
+		 * Either compression type was unspecified, or we found our
+		 * compressor; either way, we're good to go.
+		 */
+		this->usecount++;
+		spin_unlock(&jffs2_compressor_list_lock);
+
+		*datalen  = orig_slen;
+		*cdatalen = orig_dlen;
+		err = this->compress(data_in, output_buf, datalen, cdatalen);
+
+		spin_lock(&jffs2_compressor_list_lock);
+		this->usecount--;
+		if (!err) {
+			/* Success */
+			ret = this->compr;
+			this->stat_compr_blocks++;
+			this->stat_compr_orig_size += *datalen;
+			this->stat_compr_new_size += *cdatalen;
+			break;
+		}
+	}
+	spin_unlock(&jffs2_compressor_list_lock);
+	if (ret == JFFS2_COMPR_NONE)
+		kfree(output_buf);
+	else
+		*cpage_out = output_buf;
+
+	return ret;
+}
+
+/* jffs2_compress:
+ * @data_in: Pointer to uncompressed data
+ * @cpage_out: Pointer to returned pointer to buffer for compressed data
+ * @datalen: On entry, holds the amount of data available for compression.
+ *	On exit, expected to hold the amount of data actually compressed.
+ * @cdatalen: On entry, holds the amount of space available for compressed
+ *	data. On exit, expected to hold the actual size of the compressed
+ *	data.
+ *
+ * Returns: Lower byte to be stored with data indicating compression type used.
+ * Zero is used to show that the data could not be compressed - the
+ * compressed version was actually larger than the original.
+ * Upper byte will be used later. (soon)
+ *
+ * If the cdata buffer isn't large enough to hold all the uncompressed data,
+ * jffs2_compress should compress as much as will fit, and should set
+ * *datalen accordingly to show the amount of data which were compressed.
+ */
+uint16_t jffs2_compress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
+			unsigned char *data_in, unsigned char **cpage_out,
+			uint32_t *datalen, uint32_t *cdatalen)
+{
+	int ret = JFFS2_COMPR_NONE;
+	int mode, compr_ret;
+	struct jffs2_compressor *this, *best=NULL;
+	unsigned char *output_buf = NULL, *tmp_buf;
+	uint32_t orig_slen, orig_dlen;
+	uint32_t best_slen=0, best_dlen=0;
+
+	if (c->mount_opts.override_compr)
+		mode = c->mount_opts.compr;
+	else
+		mode = jffs2_compression_mode;
+
+	switch (mode) {
+	case JFFS2_COMPR_MODE_NONE:
+		break;
+	case JFFS2_COMPR_MODE_PRIORITY:
+		ret = jffs2_selected_compress(0, data_in, cpage_out, datalen,
+				cdatalen);
+		break;
+	case JFFS2_COMPR_MODE_SIZE:
+	case JFFS2_COMPR_MODE_FAVOURLZO:
+		orig_slen = *datalen;
+		orig_dlen = *cdatalen;
+		spin_lock(&jffs2_compressor_list_lock);
+		list_for_each_entry(this, &jffs2_compressor_list, list) {
+			/* Skip decompress-only backwards-compatibility and disabled modules */
+			if ((!this->compress)||(this->disabled))
+				continue;
+			/* Allocating memory for output buffer if necessary */
+			if ((this->compr_buf_size < orig_slen) && (this->compr_buf)) {
+				spin_unlock(&jffs2_compressor_list_lock);
+				kfree(this->compr_buf);
+				spin_lock(&jffs2_compressor_list_lock);
+				this->compr_buf_size=0;
+				this->compr_buf=NULL;
+			}
+			if (!this->compr_buf) {
+				spin_unlock(&jffs2_compressor_list_lock);
+				tmp_buf = kmalloc(orig_slen, GFP_KERNEL);
+				spin_lock(&jffs2_compressor_list_lock);
+				if (!tmp_buf) {
+					pr_warn("No memory for compressor allocation. (%d bytes)\n",
+						orig_slen);
+					continue;
+				}
+				else {
+					this->compr_buf = tmp_buf;
+					this->compr_buf_size = orig_slen;
+				}
+			}
+			this->usecount++;
+			spin_unlock(&jffs2_compressor_list_lock);
+			*datalen  = orig_slen;
+			*cdatalen = orig_dlen;
+			compr_ret = this->compress(data_in, this->compr_buf, datalen, cdatalen);
+			spin_lock(&jffs2_compressor_list_lock);
+			this->usecount--;
+			if (!compr_ret) {
+				if (((!best_dlen) || jffs2_is_best_compression(this, best, *cdatalen, best_dlen))
+						&& (*cdatalen < *datalen)) {
+					best_dlen = *cdatalen;
+					best_slen = *datalen;
+					best = this;
+				}
+			}
+		}
+		if (best_dlen) {
+			*cdatalen = best_dlen;
+			*datalen  = best_slen;
+			output_buf = best->compr_buf;
+			best->compr_buf = NULL;
+			best->compr_buf_size = 0;
+			best->stat_compr_blocks++;
+			best->stat_compr_orig_size += best_slen;
+			best->stat_compr_new_size  += best_dlen;
+			ret = best->compr;
+			*cpage_out = output_buf;
+		}
+		spin_unlock(&jffs2_compressor_list_lock);
+		break;
+	case JFFS2_COMPR_MODE_FORCELZO:
+		ret = jffs2_selected_compress(JFFS2_COMPR_LZO, data_in,
+				cpage_out, datalen, cdatalen);
+		break;
+	case JFFS2_COMPR_MODE_FORCEZLIB:
+		ret = jffs2_selected_compress(JFFS2_COMPR_ZLIB, data_in,
+				cpage_out, datalen, cdatalen);
+		break;
+	default:
+		pr_err("unknown compression mode\n");
+	}
+
+	if (ret == JFFS2_COMPR_NONE) {
+		*cpage_out = data_in;
+		*datalen = *cdatalen;
+		none_stat_compr_blocks++;
+		none_stat_compr_size += *datalen;
+	}
+	return ret;
+}
+
+int jffs2_decompress(struct jffs2_sb_info *c, struct jffs2_inode_info *f,
+		     uint16_t comprtype, unsigned char *cdata_in,
+		     unsigned char *data_out, uint32_t cdatalen, uint32_t datalen)
+{
+	struct jffs2_compressor *this;
+	int ret;
+
+	/* Older code had a bug where it would write non-zero 'usercompr'
+	   fields. Deal with it. */
+	if ((comprtype & 0xff) <= JFFS2_COMPR_ZLIB)
+		comprtype &= 0xff;
+
+	switch (comprtype & 0xff) {
+	case JFFS2_COMPR_NONE:
+		/* This should be special-cased elsewhere, but we might as well deal with it */
+		memcpy(data_out, cdata_in, datalen);
+		none_stat_decompr_blocks++;
+		break;
+	case JFFS2_COMPR_ZERO:
+		memset(data_out, 0, datalen);
+		break;
+	default:
+		spin_lock(&jffs2_compressor_list_lock);
+		list_for_each_entry(this, &jffs2_compressor_list, list) {
+			if (comprtype == this->compr) {
+				this->usecount++;
+				spin_unlock(&jffs2_compressor_list_lock);
+				ret = this->decompress(cdata_in, data_out, cdatalen, datalen);
+				spin_lock(&jffs2_compressor_list_lock);
+				if (ret) {
+					pr_warn("Decompressor \"%s\" returned %d\n",
+						this->name, ret);
+				}
+				else {
+					this->stat_decompr_blocks++;
+				}
+				this->usecount--;
+				spin_unlock(&jffs2_compressor_list_lock);
+				return ret;
+			}
+		}
+		pr_warn("compression type 0x%02x not available\n", comprtype);
+		spin_unlock(&jffs2_compressor_list_lock);
+		return -EIO;
+	}
+	return 0;
+}
+
+int jffs2_register_compressor(struct jffs2_compressor *comp)
+{
+	struct jffs2_compressor *this;
+
+	if (!comp->name) {
+		pr_warn("NULL compressor name at registering JFFS2 compressor. Failed.\n");
+		return -1;
+	}
+	comp->compr_buf_size=0;
+	comp->compr_buf=NULL;
+	comp->usecount=0;
+	comp->stat_compr_orig_size=0;
+	comp->stat_compr_new_size=0;
+	comp->stat_compr_blocks=0;
+	comp->stat_decompr_blocks=0;
+	jffs2_dbg(1, "Registering JFFS2 compressor \"%s\"\n", comp->name);
+
+	spin_lock(&jffs2_compressor_list_lock);
+
+	list_for_each_entry(this, &jffs2_compressor_list, list) {
+		if (this->priority < comp->priority) {
+			list_add(&comp->list, this->list.prev);
+			goto out;
+		}
+	}
+	list_add_tail(&comp->list, &jffs2_compressor_list);
+out:
+	D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
+		printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
+	})
+
+	spin_unlock(&jffs2_compressor_list_lock);
+
+	return 0;
+}
+
+int jffs2_unregister_compressor(struct jffs2_compressor *comp)
+{
+	D2(struct jffs2_compressor *this);
+
+	jffs2_dbg(1, "Unregistering JFFS2 compressor \"%s\"\n", comp->name);
+
+	spin_lock(&jffs2_compressor_list_lock);
+
+	if (comp->usecount) {
+		spin_unlock(&jffs2_compressor_list_lock);
+		pr_warn("Compressor module is in use. Unregister failed.\n");
+		return -1;
+	}
+	list_del(&comp->list);
+
+	D2(list_for_each_entry(this, &jffs2_compressor_list, list) {
+		printk(KERN_DEBUG "Compressor \"%s\", prio %d\n", this->name, this->priority);
+	})
+	spin_unlock(&jffs2_compressor_list_lock);
+	return 0;
+}
+
+void jffs2_free_comprbuf(unsigned char *comprbuf, unsigned char *orig)
+{
+	if (orig != comprbuf)
+		kfree(comprbuf);
+}
+
+int __init jffs2_compressors_init(void)
+{
+	int ret = 0;
+/* Registering compressors */
+	ret = jffs2_zlib_init();
+	if (ret)
+		goto exit;
+	ret = jffs2_rtime_init();
+	if (ret)
+		goto exit_zlib;
+	ret = jffs2_rubinmips_init();
+	if (ret)
+		goto exit_rtime;
+	ret = jffs2_dynrubin_init();
+	if (ret)
+		goto exit_runinmips;
+	ret = jffs2_lzo_init();
+	if (ret)
+		goto exit_dynrubin;
+
+
+/* Setting default compression mode */
+#ifdef CONFIG_JFFS2_CMODE_NONE
+	jffs2_compression_mode = JFFS2_COMPR_MODE_NONE;
+	jffs2_dbg(1, "default compression mode: none\n");
+#else
+#ifdef CONFIG_JFFS2_CMODE_SIZE
+	jffs2_compression_mode = JFFS2_COMPR_MODE_SIZE;
+	jffs2_dbg(1, "default compression mode: size\n");
+#else
+#ifdef CONFIG_JFFS2_CMODE_FAVOURLZO
+	jffs2_compression_mode = JFFS2_COMPR_MODE_FAVOURLZO;
+	jffs2_dbg(1, "default compression mode: favourlzo\n");
+#else
+	jffs2_dbg(1, "default compression mode: priority\n");
+#endif
+#endif
+#endif
+	return 0;
+
+exit_dynrubin:
+	jffs2_dynrubin_exit();
+exit_runinmips:
+	jffs2_rubinmips_exit();
+exit_rtime:
+	jffs2_rtime_exit();
+exit_zlib:
+	jffs2_zlib_exit();
+exit:
+	return ret;
+}
+
+int jffs2_compressors_exit(void)
+{
+/* Unregistering compressors */
+	jffs2_lzo_exit();
+	jffs2_dynrubin_exit();
+	jffs2_rubinmips_exit();
+	jffs2_rtime_exit();
+	jffs2_zlib_exit();
+	return 0;
+}