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, 135 insertions, 0 deletions

diff --git a/tools/perf/util/c2c.h b/tools/perf/util/c2c.h
new file mode 100644
index 000000000..53f024e25
--- /dev/null
+++ b/tools/perf/util/c2c.h
@@ -0,0 +1,135 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PERF_UTIL_C2C_H
+#define __PERF_UTIL_C2C_H
+
+#include <stdbool.h>
+#include <stdint.h>
+#include <linux/types.h>
+#include "hist.h"
+#include "mem-events.h"
+#include "stat.h"
+
+struct sort_entry;
+
+struct c2c_hists {
+	struct hists		hists;
+	struct perf_hpp_list	list;
+	struct c2c_stats	stats;
+};
+
+struct compute_stats {
+	struct stats		 lcl_hitm;
+	struct stats		 rmt_hitm;
+	struct stats		 lcl_peer;
+	struct stats		 rmt_peer;
+	struct stats		 load;
+};
+
+struct c2c_hist_entry {
+	struct c2c_hists	*hists;
+	struct evsel		*evsel;
+	struct c2c_stats	 stats;
+	unsigned long		*cpuset;
+	unsigned long		*nodeset;
+	struct c2c_stats	*node_stats;
+	unsigned int		 cacheline_idx;
+
+	struct compute_stats	 cstats;
+
+	unsigned long		 paddr;
+	unsigned long		 paddr_cnt;
+	bool			 paddr_zero;
+	char			*nodestr;
+
+	/*
+	 * must be at the end,
+	 * because of its callchain dynamic entry
+	 */
+	struct hist_entry	he;
+};
+
+#define C2C_HEADER_MAX 2
+
+struct c2c_header {
+	struct {
+		const char *text;
+		int	    span;
+	} line[C2C_HEADER_MAX];
+};
+
+struct c2c_dimension {
+	struct c2c_header	 header;
+	const char		*name;
+	int			 width;
+	struct sort_entry	*se;
+
+	int64_t (*cmp)(struct perf_hpp_fmt *fmt,
+		       struct hist_entry *left, struct hist_entry *right);
+	int   (*entry)(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp,
+		       struct hist_entry *he);
+	int   (*color)(struct perf_hpp_fmt *fmt, struct perf_hpp *hpp,
+		       struct hist_entry *he);
+};
+
+struct c2c_fmt {
+	struct perf_hpp_fmt	 fmt;
+	struct c2c_dimension	*dim;
+};
+
+#define SYMBOL_WIDTH 30
+
+#define HEADER_LOW(__h)			\
+	{				\
+		.line[1] = {		\
+			.text = __h,	\
+		},			\
+	}
+
+#define HEADER_BOTH(__h0, __h1)		\
+	{				\
+		.line[0] = {		\
+			.text = __h0,	\
+		},			\
+		.line[1] = {		\
+			.text = __h1,	\
+		},			\
+	}
+
+void c2c_fmt_free(struct perf_hpp_fmt *fmt);
+bool c2c_fmt_equal(struct perf_hpp_fmt *a, struct perf_hpp_fmt *b);
+
+/*
+ * Build the function-view hierarchy. Returns -EOPNOTSUPP when @cl_sort lacks
+ * iaddr. On success, *@hists remains valid until the next
+ * c2c_function__build() or c2c_function__reset(). On failure, *@hists is
+ * NULL.
+ */
+int c2c_function__build(struct c2c_hists *cl_hists, const char *cl_sort,
+			bool symbol_full, struct hists **hists);
+void c2c_function__reset(void);
+/* Valid only between a successful build and c2c_function__reset(). */
+struct hist_entry *c2c_function__find_cacheline(struct hist_entry *he);
+
+/* Inputs and TUI callback supplied by the c2c command. */
+struct c2c_function_view_args {
+	/* Source cacheline histograms used by the common model. */
+	struct c2c_hists	*cl_hists;
+	/* --coalesce field list, used to require iaddr. */
+	const char		*cl_sort;
+	/* Do not cap long symbol names. */
+	bool			 symbol_full;
+	/* Open the cacheline detail view for @he. */
+	int			(*browse_cacheline)(struct hist_entry *he);
+};
+
+#ifdef HAVE_SLANG_SUPPORT
+int perf_c2c__browse_function_view(struct c2c_function_view_args *args);
+#else
+static inline int
+perf_c2c__browse_function_view(struct c2c_function_view_args *args __maybe_unused)
+{
+	return 0;
+}
+#endif
+
+#endif /* __PERF_UTIL_C2C_H */