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, 141 insertions, 0 deletions

diff --git a/tools/testing/vma/shared.h b/tools/testing/vma/shared.h
new file mode 100644
index 000000000..97cd7a679
--- /dev/null
+++ b/tools/testing/vma/shared.h
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "generated/bit-length.h"
+#include "maple-shared.h"
+#include "vma_internal.h"
+#include "../../../mm/vma.h"
+
+/* Simple test runner. Assumes local num_[fail, tests] counters. */
+#define TEST(name)							\
+	do {								\
+		(*num_tests)++;						\
+		if (!test_##name()) {					\
+			(*num_fail)++;					\
+			fprintf(stderr, "Test " #name " FAILED\n");	\
+		}							\
+	} while (0)
+
+#define __ASSERT_TRUE(_expr, _fmt, ...)					   \
+	do {								   \
+		if (!(_expr)) {						   \
+			fprintf(stderr,					   \
+				"Assert FAILED at %s:%d:%s(): %s is FALSE" \
+				_fmt ".\n",				   \
+				__FILE__, __LINE__, __FUNCTION__, #_expr   \
+				__VA_OPT__(,) __VA_ARGS__);		   \
+			return false;					   \
+		}							   \
+	} while (0)
+
+#define __TO_SCALAR(x)	((unsigned long long)(uintptr_t)(x))
+
+#define ASSERT_TRUE(_expr) __ASSERT_TRUE(_expr, "")
+#define ASSERT_FALSE(_expr) ASSERT_TRUE(!(_expr))
+#define ASSERT_EQ(_val1, _val2) do {				 \
+	__typeof__(_val1) __val1 = (_val1);			 \
+	__typeof__(_val2) __val2 = (_val2);			 \
+	__ASSERT_TRUE(__val1 == __val2, " (0x%llx != 0x%llx)",	 \
+		      __TO_SCALAR(__val1), __TO_SCALAR(__val2)); \
+	} while (0)
+
+#define ASSERT_NE(_val1, _val2) do {				 \
+	__typeof__(_val1) __val1 = (_val1);			 \
+	__typeof__(_val2) __val2 = (_val2);			 \
+	__ASSERT_TRUE(__val1 != __val2, " (0x%llx == 0x%llx)",	 \
+		      __TO_SCALAR(__val1), __TO_SCALAR(__val2)); \
+	} while (0)
+
+#define ASSERT_FLAGS_SAME_MASK(_flags, _flags_other) \
+	ASSERT_TRUE(vma_flags_same_mask((_flags), (_flags_other)))
+
+#define ASSERT_FLAGS_NOT_SAME_MASK(_flags, _flags_other) \
+	ASSERT_FALSE(vma_flags_same_mask((_flags), (_flags_other)))
+
+#define ASSERT_FLAGS_SAME(_flags, ...) \
+	ASSERT_TRUE(vma_flags_same(_flags, __VA_ARGS__))
+
+#define ASSERT_FLAGS_NOT_SAME(_flags, ...) \
+	ASSERT_FALSE(vma_flags_same(_flags, __VA_ARGS__))
+
+#define ASSERT_FLAGS_EMPTY(_flags) \
+	ASSERT_TRUE(vma_flags_empty(_flags))
+
+#define ASSERT_FLAGS_NONEMPTY(_flags) \
+	ASSERT_FALSE(vma_flags_empty(_flags))
+
+extern bool fail_prealloc;
+
+/* Override vma_iter_prealloc() so we can choose to fail it. */
+#define vma_iter_prealloc(vmi, vma)					\
+	(fail_prealloc ? -ENOMEM : mas_preallocate(&(vmi)->mas, (vma), GFP_KERNEL))
+
+#define CONFIG_DEFAULT_MMAP_MIN_ADDR 65536
+
+extern unsigned long mmap_min_addr;
+extern unsigned long dac_mmap_min_addr;
+extern unsigned long stack_guard_gap;
+
+extern const struct vm_operations_struct vma_dummy_vm_ops;
+extern struct anon_vma dummy_anon_vma;
+extern struct task_struct __current;
+
+/*
+ * Helper function which provides a wrapper around a merge existing VMA
+ * operation.
+ *
+ * Declared in main.c as uses static VMA function.
+ */
+struct vm_area_struct *merge_existing(struct vma_merge_struct *vmg);
+
+/*
+ * Helper function to allocate a VMA and link it to the tree.
+ *
+ * Declared in main.c as uses static VMA function.
+ */
+int attach_vma(struct mm_struct *mm, struct vm_area_struct *vma);
+
+/* Helper function providing a dummy vm_ops->close() method.*/
+static inline void dummy_close(struct vm_area_struct *)
+{
+}
+
+/* Helper function to simply allocate a VMA. */
+struct vm_area_struct *alloc_vma(struct mm_struct *mm,
+		unsigned long start, unsigned long end,
+		pgoff_t pgoff, vma_flags_t vma_flags);
+
+/* Helper function to detach and free a VMA. */
+void detach_free_vma(struct vm_area_struct *vma);
+
+/* Helper function to allocate a VMA and link it to the tree. */
+struct vm_area_struct *alloc_and_link_vma(struct mm_struct *mm,
+		unsigned long start, unsigned long end,
+		pgoff_t pgoff, vma_flags_t vma_flags);
+
+/*
+ * Helper function to reset the dummy anon_vma to indicate it has not been
+ * duplicated.
+ */
+void reset_dummy_anon_vma(void);
+
+/*
+ * Helper function to remove all VMAs and destroy the maple tree associated with
+ * a virtual address space. Returns a count of VMAs in the tree.
+ */
+int cleanup_mm(struct mm_struct *mm, struct vma_iterator *vmi);
+
+/* Helper function to determine if VMA has had vma_start_write() performed. */
+bool vma_write_started(struct vm_area_struct *vma);
+
+void __vma_set_dummy_anon_vma(struct vm_area_struct *vma,
+		struct anon_vma_chain *avc, struct anon_vma *anon_vma);
+
+/* Provide a simple dummy VMA/anon_vma dummy setup for testing. */
+void vma_set_dummy_anon_vma(struct vm_area_struct *vma,
+			    struct anon_vma_chain *avc);