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, 447 insertions, 0 deletions

diff --git a/fs/jffs2/compr_rubin.c b/fs/jffs2/compr_rubin.c
new file mode 100644
index 000000000..9854253d0
--- /dev/null
+++ b/fs/jffs2/compr_rubin.c
@@ -0,0 +1,447 @@
+/*
+ * JFFS2 -- Journalling Flash File System, Version 2.
+ *
+ * Copyright © 2001-2007 Red Hat, Inc.
+ * Copyright © 2004-2010 David Woodhouse <dwmw2@infradead.org>
+ *
+ * Created by Arjan van de Ven <arjanv@redhat.com>
+ *
+ * For licensing information, see the file 'LICENCE' in this directory.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/jffs2.h>
+#include <linux/errno.h>
+#include "compr.h"
+
+
+#define RUBIN_REG_SIZE   16
+#define UPPER_BIT_RUBIN    (((long) 1)<<(RUBIN_REG_SIZE-1))
+#define LOWER_BITS_RUBIN   ((((long) 1)<<(RUBIN_REG_SIZE-1))-1)
+
+
+#define BIT_DIVIDER_MIPS 1043
+static int bits_mips[8] = { 277, 249, 290, 267, 229, 341, 212, 241};
+
+struct pushpull {
+	unsigned char *buf;
+	unsigned int buflen;
+	unsigned int ofs;
+	unsigned int reserve;
+};
+
+struct rubin_state {
+	unsigned long p;
+	unsigned long q;
+	unsigned long rec_q;
+	long bit_number;
+	struct pushpull pp;
+	int bit_divider;
+	int bits[8];
+};
+
+static inline void init_pushpull(struct pushpull *pp, char *buf,
+				 unsigned buflen, unsigned ofs,
+				 unsigned reserve)
+{
+	pp->buf = buf;
+	pp->buflen = buflen;
+	pp->ofs = ofs;
+	pp->reserve = reserve;
+}
+
+static inline int pushbit(struct pushpull *pp, int bit, int use_reserved)
+{
+	if (pp->ofs >= pp->buflen - (use_reserved?0:pp->reserve))
+		return -ENOSPC;
+
+	if (bit)
+		pp->buf[pp->ofs >> 3] |= (1<<(7-(pp->ofs & 7)));
+	else
+		pp->buf[pp->ofs >> 3] &= ~(1<<(7-(pp->ofs & 7)));
+
+	pp->ofs++;
+
+	return 0;
+}
+
+static inline int pushedbits(struct pushpull *pp)
+{
+	return pp->ofs;
+}
+
+static inline int pullbit(struct pushpull *pp)
+{
+	int bit;
+
+	bit = (pp->buf[pp->ofs >> 3] >> (7-(pp->ofs & 7))) & 1;
+
+	pp->ofs++;
+	return bit;
+}
+
+
+static void init_rubin(struct rubin_state *rs, int div, int *bits)
+{
+	int c;
+
+	rs->q = 0;
+	rs->p = (long) (2 * UPPER_BIT_RUBIN);
+	rs->bit_number = (long) 0;
+	rs->bit_divider = div;
+
+	for (c=0; c<8; c++)
+		rs->bits[c] = bits[c];
+}
+
+
+static int encode(struct rubin_state *rs, long A, long B, int symbol)
+{
+
+	long i0, i1;
+	int ret;
+
+	while ((rs->q >= UPPER_BIT_RUBIN) ||
+	       ((rs->p + rs->q) <= UPPER_BIT_RUBIN)) {
+		rs->bit_number++;
+
+		ret = pushbit(&rs->pp, (rs->q & UPPER_BIT_RUBIN) ? 1 : 0, 0);
+		if (ret)
+			return ret;
+		rs->q &= LOWER_BITS_RUBIN;
+		rs->q <<= 1;
+		rs->p <<= 1;
+	}
+	i0 = A * rs->p / (A + B);
+	if (i0 <= 0)
+		i0 = 1;
+
+	if (i0 >= rs->p)
+		i0 = rs->p - 1;
+
+	i1 = rs->p - i0;
+
+	if (symbol == 0)
+		rs->p = i0;
+	else {
+		rs->p = i1;
+		rs->q += i0;
+	}
+	return 0;
+}
+
+
+static void end_rubin(struct rubin_state *rs)
+{
+
+	int i;
+
+	for (i = 0; i < RUBIN_REG_SIZE; i++) {
+		pushbit(&rs->pp, (UPPER_BIT_RUBIN & rs->q) ? 1 : 0, 1);
+		rs->q &= LOWER_BITS_RUBIN;
+		rs->q <<= 1;
+	}
+}
+
+
+static void init_decode(struct rubin_state *rs, int div, int *bits)
+{
+	init_rubin(rs, div, bits);
+
+	/* behalve lower */
+	rs->rec_q = 0;
+
+	for (rs->bit_number = 0; rs->bit_number++ < RUBIN_REG_SIZE;
+	     rs->rec_q = rs->rec_q * 2 + (long) (pullbit(&rs->pp)))
+		;
+}
+
+static void __do_decode(struct rubin_state *rs, unsigned long p,
+			unsigned long q)
+{
+	register unsigned long lower_bits_rubin = LOWER_BITS_RUBIN;
+	unsigned long rec_q;
+	int c, bits = 0;
+
+	/*
+	 * First, work out how many bits we need from the input stream.
+	 * Note that we have already done the initial check on this
+	 * loop prior to calling this function.
+	 */
+	do {
+		bits++;
+		q &= lower_bits_rubin;
+		q <<= 1;
+		p <<= 1;
+	} while ((q >= UPPER_BIT_RUBIN) || ((p + q) <= UPPER_BIT_RUBIN));
+
+	rs->p = p;
+	rs->q = q;
+
+	rs->bit_number += bits;
+
+	/*
+	 * Now get the bits.  We really want this to be "get n bits".
+	 */
+	rec_q = rs->rec_q;
+	do {
+		c = pullbit(&rs->pp);
+		rec_q &= lower_bits_rubin;
+		rec_q <<= 1;
+		rec_q += c;
+	} while (--bits);
+	rs->rec_q = rec_q;
+}
+
+static int decode(struct rubin_state *rs, long A, long B)
+{
+	unsigned long p = rs->p, q = rs->q;
+	long i0, threshold;
+	int symbol;
+
+	if (q >= UPPER_BIT_RUBIN || ((p + q) <= UPPER_BIT_RUBIN))
+		__do_decode(rs, p, q);
+
+	i0 = A * rs->p / (A + B);
+	if (i0 <= 0)
+		i0 = 1;
+
+	if (i0 >= rs->p)
+		i0 = rs->p - 1;
+
+	threshold = rs->q + i0;
+	symbol = rs->rec_q >= threshold;
+	if (rs->rec_q >= threshold) {
+		rs->q += i0;
+		i0 = rs->p - i0;
+	}
+
+	rs->p = i0;
+
+	return symbol;
+}
+
+
+
+static int out_byte(struct rubin_state *rs, unsigned char byte)
+{
+	int i, ret;
+	struct rubin_state rs_copy;
+	rs_copy = *rs;
+
+	for (i=0; i<8; i++) {
+		ret = encode(rs, rs->bit_divider-rs->bits[i],
+			     rs->bits[i], byte & 1);
+		if (ret) {
+			/* Failed. Restore old state */
+			*rs = rs_copy;
+			return ret;
+		}
+		byte >>= 1 ;
+	}
+	return 0;
+}
+
+static int in_byte(struct rubin_state *rs)
+{
+	int i, result = 0, bit_divider = rs->bit_divider;
+
+	for (i = 0; i < 8; i++)
+		result |= decode(rs, bit_divider - rs->bits[i],
+				 rs->bits[i]) << i;
+
+	return result;
+}
+
+
+
+static int rubin_do_compress(int bit_divider, int *bits, unsigned char *data_in,
+			     unsigned char *cpage_out, uint32_t *sourcelen,
+			     uint32_t *dstlen)
+	{
+	int outpos = 0;
+	int pos=0;
+	struct rubin_state rs;
+
+	init_pushpull(&rs.pp, cpage_out, *dstlen * 8, 0, 32);
+
+	init_rubin(&rs, bit_divider, bits);
+
+	while (pos < (*sourcelen) && !out_byte(&rs, data_in[pos]))
+		pos++;
+
+	end_rubin(&rs);
+
+	/* Tell the caller how much we managed to compress,
+	 * and how much space it took */
+
+	outpos = (pushedbits(&rs.pp)+7)/8;
+
+	if (outpos >= pos)
+		return -1; /* We didn't actually compress */
+	*sourcelen = pos;
+	*dstlen = outpos;
+	return 0;
+}
+#if 0
+/* _compress returns the compressed size, -1 if bigger */
+int jffs2_rubinmips_compress(unsigned char *data_in, unsigned char *cpage_out,
+		   uint32_t *sourcelen, uint32_t *dstlen)
+{
+	return rubin_do_compress(BIT_DIVIDER_MIPS, bits_mips, data_in,
+				 cpage_out, sourcelen, dstlen);
+}
+#endif
+static int jffs2_dynrubin_compress(unsigned char *data_in,
+				   unsigned char *cpage_out,
+				   uint32_t *sourcelen, uint32_t *dstlen)
+{
+	int bits[8];
+	unsigned char histo[256];
+	int i;
+	int ret;
+	uint32_t mysrclen, mydstlen;
+
+	mysrclen = *sourcelen;
+	mydstlen = *dstlen - 8;
+
+	if (*dstlen <= 12)
+		return -1;
+
+	memset(histo, 0, 256);
+	for (i=0; i<mysrclen; i++)
+		histo[data_in[i]]++;
+	memset(bits, 0, sizeof(int)*8);
+	for (i=0; i<256; i++) {
+		if (i&128)
+			bits[7] += histo[i];
+		if (i&64)
+			bits[6] += histo[i];
+		if (i&32)
+			bits[5] += histo[i];
+		if (i&16)
+			bits[4] += histo[i];
+		if (i&8)
+			bits[3] += histo[i];
+		if (i&4)
+			bits[2] += histo[i];
+		if (i&2)
+			bits[1] += histo[i];
+		if (i&1)
+			bits[0] += histo[i];
+	}
+
+	for (i=0; i<8; i++) {
+		bits[i] = (bits[i] * 256) / mysrclen;
+		if (!bits[i]) bits[i] = 1;
+		if (bits[i] > 255) bits[i] = 255;
+		cpage_out[i] = bits[i];
+	}
+
+	ret = rubin_do_compress(256, bits, data_in, cpage_out+8, &mysrclen,
+				&mydstlen);
+	if (ret)
+		return ret;
+
+	/* Add back the 8 bytes we took for the probabilities */
+	mydstlen += 8;
+
+	if (mysrclen <= mydstlen) {
+		/* We compressed */
+		return -1;
+	}
+
+	*sourcelen = mysrclen;
+	*dstlen = mydstlen;
+	return 0;
+}
+
+static void rubin_do_decompress(int bit_divider, int *bits,
+				unsigned char *cdata_in, 
+				unsigned char *page_out, uint32_t srclen,
+				uint32_t destlen)
+{
+	int outpos = 0;
+	struct rubin_state rs;
+
+	init_pushpull(&rs.pp, cdata_in, srclen, 0, 0);
+	init_decode(&rs, bit_divider, bits);
+
+	while (outpos < destlen)
+		page_out[outpos++] = in_byte(&rs);
+}
+
+
+static int jffs2_rubinmips_decompress(unsigned char *data_in,
+				      unsigned char *cpage_out,
+				      uint32_t sourcelen, uint32_t dstlen)
+{
+	rubin_do_decompress(BIT_DIVIDER_MIPS, bits_mips, data_in,
+			    cpage_out, sourcelen, dstlen);
+	return 0;
+}
+
+static int jffs2_dynrubin_decompress(unsigned char *data_in,
+				     unsigned char *cpage_out,
+				     uint32_t sourcelen, uint32_t dstlen)
+{
+	int bits[8];
+	int c;
+
+	for (c=0; c<8; c++)
+		bits[c] = data_in[c];
+
+	rubin_do_decompress(256, bits, data_in+8, cpage_out, sourcelen-8,
+			    dstlen);
+	return 0;
+}
+
+static struct jffs2_compressor jffs2_rubinmips_comp = {
+	.priority = JFFS2_RUBINMIPS_PRIORITY,
+	.name = "rubinmips",
+	.compr = JFFS2_COMPR_DYNRUBIN,
+	.compress = NULL, /*&jffs2_rubinmips_compress,*/
+	.decompress = &jffs2_rubinmips_decompress,
+#ifdef JFFS2_RUBINMIPS_DISABLED
+	.disabled = 1,
+#else
+	.disabled = 0,
+#endif
+};
+
+int jffs2_rubinmips_init(void)
+{
+	return jffs2_register_compressor(&jffs2_rubinmips_comp);
+}
+
+void jffs2_rubinmips_exit(void)
+{
+	jffs2_unregister_compressor(&jffs2_rubinmips_comp);
+}
+
+static struct jffs2_compressor jffs2_dynrubin_comp = {
+	.priority = JFFS2_DYNRUBIN_PRIORITY,
+	.name = "dynrubin",
+	.compr = JFFS2_COMPR_RUBINMIPS,
+	.compress = jffs2_dynrubin_compress,
+	.decompress = &jffs2_dynrubin_decompress,
+#ifdef JFFS2_DYNRUBIN_DISABLED
+	.disabled = 1,
+#else
+	.disabled = 0,
+#endif
+};
+
+int jffs2_dynrubin_init(void)
+{
+	return jffs2_register_compressor(&jffs2_dynrubin_comp);
+}
+
+void jffs2_dynrubin_exit(void)
+{
+	jffs2_unregister_compressor(&jffs2_dynrubin_comp);
+}