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, 388 insertions, 0 deletions

diff --git a/lib/kunit/assert_test.c b/lib/kunit/assert_test.c
new file mode 100644
index 000000000..4a5967712
--- /dev/null
+++ b/lib/kunit/assert_test.c
@@ -0,0 +1,388 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * KUnit test for the assertion formatting functions.
+ * Author: Ivan Orlov <ivan.orlov0322@gmail.com>
+ */
+#include <kunit/test.h>
+#include "string-stream.h"
+
+#define TEST_PTR_EXPECTED_BUF_SIZE 32
+#define HEXDUMP_TEST_BUF_LEN 5
+#define ASSERT_TEST_EXPECT_CONTAIN(test, str, substr) KUNIT_EXPECT_TRUE(test, strstr(str, substr))
+#define ASSERT_TEST_EXPECT_NCONTAIN(test, str, substr) KUNIT_EXPECT_FALSE(test, strstr(str, substr))
+
+static void kunit_test_is_literal(struct kunit *test)
+{
+	KUNIT_EXPECT_TRUE(test, is_literal("5", 5));
+	KUNIT_EXPECT_TRUE(test, is_literal("0", 0));
+	KUNIT_EXPECT_TRUE(test, is_literal("1234567890", 1234567890));
+	KUNIT_EXPECT_TRUE(test, is_literal("-1234567890", -1234567890));
+	KUNIT_EXPECT_FALSE(test, is_literal("05", 5));
+	KUNIT_EXPECT_FALSE(test, is_literal("", 0));
+	KUNIT_EXPECT_FALSE(test, is_literal("-0", 0));
+	KUNIT_EXPECT_FALSE(test, is_literal("12#45", 1245));
+}
+
+static void kunit_test_is_str_literal(struct kunit *test)
+{
+	KUNIT_EXPECT_TRUE(test, is_str_literal("\"Hello, World!\"", "Hello, World!"));
+	KUNIT_EXPECT_TRUE(test, is_str_literal("\"\"", ""));
+	KUNIT_EXPECT_TRUE(test, is_str_literal("\"\"\"", "\""));
+	KUNIT_EXPECT_FALSE(test, is_str_literal("", ""));
+	KUNIT_EXPECT_FALSE(test, is_str_literal("\"", "\""));
+	KUNIT_EXPECT_FALSE(test, is_str_literal("\"Abacaba", "Abacaba"));
+	KUNIT_EXPECT_FALSE(test, is_str_literal("Abacaba\"", "Abacaba"));
+	KUNIT_EXPECT_FALSE(test, is_str_literal("\"Abacaba\"", "\"Abacaba\""));
+}
+
+KUNIT_DEFINE_ACTION_WRAPPER(kfree_wrapper, kfree, const void *);
+
+/* this function is used to get a "char *" string from the string stream and defer its cleanup  */
+static char *get_str_from_stream(struct kunit *test, struct string_stream *stream)
+{
+	char *str = string_stream_get_string(stream);
+
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, str);
+	kunit_add_action(test, kfree_wrapper, (void *)str);
+
+	return str;
+}
+
+static void kunit_test_assert_prologue(struct kunit *test)
+{
+	struct string_stream *stream;
+	char *str;
+	const struct kunit_loc location = {
+		.file = "testfile.c",
+		.line = 1337,
+	};
+
+	stream = kunit_alloc_string_stream(test, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+
+	/* Test an expectation fail prologue */
+	kunit_assert_prologue(&location, KUNIT_EXPECTATION, stream);
+	str = get_str_from_stream(test, stream);
+	ASSERT_TEST_EXPECT_CONTAIN(test, str, "EXPECTATION");
+	ASSERT_TEST_EXPECT_CONTAIN(test, str, "testfile.c");
+	ASSERT_TEST_EXPECT_CONTAIN(test, str, "1337");
+
+	/* Test an assertion fail prologue */
+	string_stream_clear(stream);
+	kunit_assert_prologue(&location, KUNIT_ASSERTION, stream);
+	str = get_str_from_stream(test, stream);
+	ASSERT_TEST_EXPECT_CONTAIN(test, str, "ASSERTION");
+	ASSERT_TEST_EXPECT_CONTAIN(test, str, "testfile.c");
+	ASSERT_TEST_EXPECT_CONTAIN(test, str, "1337");
+}
+
+/*
+ * This function accepts an arbitrary count of parameters and generates a va_format struct,
+ * which can be used to validate kunit_assert_print_msg function
+ */
+static void verify_assert_print_msg(struct kunit *test,
+				    struct string_stream *stream,
+				    char *expected, const char *format, ...)
+{
+	va_list list;
+	const struct va_format vformat = {
+		.fmt = format,
+		.va = &list,
+	};
+
+	va_start(list, format);
+	string_stream_clear(stream);
+	kunit_assert_print_msg(&vformat, stream);
+	KUNIT_EXPECT_STREQ(test, get_str_from_stream(test, stream), expected);
+}
+
+static void kunit_test_assert_print_msg(struct kunit *test)
+{
+	struct string_stream *stream;
+
+	stream = kunit_alloc_string_stream(test, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+
+	verify_assert_print_msg(test, stream, "\nTest", "Test");
+	verify_assert_print_msg(test, stream, "\nAbacaba -123 234", "%s %d %u",
+				"Abacaba", -123, 234U);
+	verify_assert_print_msg(test, stream, "", NULL);
+}
+
+/*
+ * Further code contains the tests for different assert format functions.
+ * This helper function accepts the assert format function, executes it and
+ * validates the result string from the stream by checking that all of the
+ * substrings exist in the output.
+ */
+static void validate_assert(assert_format_t format_func, struct kunit *test,
+			    const struct kunit_assert *assert,
+			    struct string_stream *stream, int num_checks, ...)
+{
+	size_t i;
+	va_list checks;
+	char *cur_substr_exp;
+	struct va_format message = { NULL, NULL };
+
+	va_start(checks, num_checks);
+	string_stream_clear(stream);
+	format_func(assert, &message, stream);
+
+	for (i = 0; i < num_checks; i++) {
+		cur_substr_exp = va_arg(checks, char *);
+		ASSERT_TEST_EXPECT_CONTAIN(test, get_str_from_stream(test, stream), cur_substr_exp);
+	}
+}
+
+static void kunit_test_unary_assert_format(struct kunit *test)
+{
+	struct string_stream *stream;
+	struct kunit_assert assert = {};
+	struct kunit_unary_assert un_assert = {
+		.assert = assert,
+		.condition = "expr",
+		.expected_true = true,
+	};
+
+	stream = kunit_alloc_string_stream(test, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+
+	validate_assert(kunit_unary_assert_format, test, &un_assert.assert,
+			stream, 2, "true", "is false");
+
+	un_assert.expected_true = false;
+	validate_assert(kunit_unary_assert_format, test, &un_assert.assert,
+			stream, 2, "false", "is true");
+}
+
+static void kunit_test_ptr_not_err_assert_format(struct kunit *test)
+{
+	struct string_stream *stream;
+	struct kunit_assert assert = {};
+	struct kunit_ptr_not_err_assert not_err_assert = {
+		.assert = assert,
+		.text = "expr",
+		.value = NULL,
+	};
+
+	stream = kunit_alloc_string_stream(test, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+
+	/* Value is NULL. The corresponding message should be printed out */
+	validate_assert(kunit_ptr_not_err_assert_format, test,
+			&not_err_assert.assert,
+			stream, 1, "null");
+
+	/* Value is not NULL, but looks like an error pointer. Error should be printed out */
+	not_err_assert.value = (void *)-12;
+	validate_assert(kunit_ptr_not_err_assert_format, test,
+			&not_err_assert.assert, stream, 2,
+			"error", "-12");
+}
+
+static void kunit_test_binary_assert_format(struct kunit *test)
+{
+	struct string_stream *stream;
+	struct kunit_assert assert = {};
+	struct kunit_binary_assert_text text = {
+		.left_text = "1 + 2",
+		.operation = "==",
+		.right_text = "2",
+	};
+	const struct kunit_binary_assert binary_assert = {
+		.assert = assert,
+		.text = &text,
+		.left_value = 3,
+		.right_value = 2,
+	};
+
+	stream = kunit_alloc_string_stream(test, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+
+	/*
+	 * Printed values should depend on the input we provide: the left text, right text, left
+	 * value and the right value.
+	 */
+	validate_assert(kunit_binary_assert_format, test, &binary_assert.assert,
+			stream, 4, "1 + 2", "2", "3", "==");
+
+	text.right_text = "4 - 2";
+	validate_assert(kunit_binary_assert_format, test, &binary_assert.assert,
+			stream, 3, "==", "1 + 2", "4 - 2");
+
+	text.left_text = "3";
+	validate_assert(kunit_binary_assert_format, test, &binary_assert.assert,
+			stream, 4, "3", "4 - 2", "2", "==");
+
+	text.right_text = "2";
+	validate_assert(kunit_binary_assert_format, test, &binary_assert.assert,
+			stream, 3, "3", "2", "==");
+}
+
+static void kunit_test_binary_ptr_assert_format(struct kunit *test)
+{
+	struct string_stream *stream;
+	struct kunit_assert assert = {};
+	char *addr_var_a, *addr_var_b;
+	static const void *var_a = (void *)0xDEADBEEF;
+	static const void *var_b = (void *)0xBADDCAFE;
+	struct kunit_binary_assert_text text = {
+		.left_text = "var_a",
+		.operation = "==",
+		.right_text = "var_b",
+	};
+	struct kunit_binary_ptr_assert binary_ptr_assert = {
+		.assert = assert,
+		.text = &text,
+		.left_value = var_a,
+		.right_value = var_b,
+	};
+
+	addr_var_a = kunit_kzalloc(test, TEST_PTR_EXPECTED_BUF_SIZE, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, addr_var_a);
+	addr_var_b = kunit_kzalloc(test, TEST_PTR_EXPECTED_BUF_SIZE, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, addr_var_b);
+	/*
+	 * Print the addresses to the buffers first.
+	 * This is necessary as we may have different count of leading zeros in the pointer
+	 * on different architectures.
+	 */
+	snprintf(addr_var_a, TEST_PTR_EXPECTED_BUF_SIZE, "%px", var_a);
+	snprintf(addr_var_b, TEST_PTR_EXPECTED_BUF_SIZE, "%px", var_b);
+
+	stream = kunit_alloc_string_stream(test, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+	validate_assert(kunit_binary_ptr_assert_format, test, &binary_ptr_assert.assert,
+			stream, 3, addr_var_a, addr_var_b, "==");
+}
+
+static void kunit_test_binary_str_assert_format(struct kunit *test)
+{
+	struct string_stream *stream;
+	struct kunit_assert assert = {};
+	static const char *var_a = "abacaba";
+	static const char *var_b = "kernel";
+	struct kunit_binary_assert_text text = {
+		.left_text = "var_a",
+		.operation = "==",
+		.right_text = "var_b",
+	};
+	struct kunit_binary_str_assert binary_str_assert = {
+		.assert = assert,
+		.text = &text,
+		.left_value = var_a,
+		.right_value = var_b,
+	};
+
+	stream = kunit_alloc_string_stream(test, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+
+	validate_assert(kunit_binary_str_assert_format, test,
+			&binary_str_assert.assert,
+			stream, 5, "var_a", "var_b", "\"abacaba\"",
+			"\"kernel\"", "==");
+
+	text.left_text = "\"abacaba\"";
+	validate_assert(kunit_binary_str_assert_format, test, &binary_str_assert.assert,
+			stream, 4, "\"abacaba\"", "var_b", "\"kernel\"", "==");
+
+	text.right_text = "\"kernel\"";
+	validate_assert(kunit_binary_str_assert_format, test, &binary_str_assert.assert,
+			stream, 3, "\"abacaba\"", "\"kernel\"", "==");
+}
+
+static const u8 hex_testbuf1[] = { 0x26, 0x74, 0x6b, 0x9c, 0x55,
+				   0x45, 0x9d, 0x47, 0xd6, 0x47,
+				   0x2,  0x89, 0x8c, 0x81, 0x94,
+				   0x12, 0xfe, 0x01 };
+static const u8 hex_testbuf2[] = { 0x26, 0x74, 0x6b, 0x9c, 0x55,
+				   0x45, 0x9d, 0x47, 0x21, 0x47,
+				   0xcd, 0x89, 0x24, 0x50, 0x94,
+				   0x12, 0xba, 0x01 };
+static void kunit_test_assert_hexdump(struct kunit *test)
+{
+	struct string_stream *stream;
+	char *str;
+	size_t i;
+	char buf[HEXDUMP_TEST_BUF_LEN];
+
+	stream = kunit_alloc_string_stream(test, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+	/* Check that we are getting output like <xx> for non-matching numbers. */
+	kunit_assert_hexdump(stream, hex_testbuf1, hex_testbuf2, sizeof(hex_testbuf1));
+	str = get_str_from_stream(test, stream);
+	for (i = 0; i < sizeof(hex_testbuf1); i++) {
+		snprintf(buf, HEXDUMP_TEST_BUF_LEN, "<%02x>", hex_testbuf1[i]);
+		if (hex_testbuf1[i] != hex_testbuf2[i])
+			ASSERT_TEST_EXPECT_CONTAIN(test, str, buf);
+	}
+	/* We shouldn't get any <xx> numbers when comparing the buffer with itself. */
+	string_stream_clear(stream);
+	kunit_assert_hexdump(stream, hex_testbuf1, hex_testbuf1, sizeof(hex_testbuf1));
+	str = get_str_from_stream(test, stream);
+	ASSERT_TEST_EXPECT_NCONTAIN(test, str, "<");
+	ASSERT_TEST_EXPECT_NCONTAIN(test, str, ">");
+}
+
+static void kunit_test_mem_assert_format(struct kunit *test)
+{
+	struct string_stream *stream;
+	struct string_stream *expected_stream;
+	struct kunit_assert assert = {};
+	static const struct kunit_binary_assert_text text = {
+		.left_text = "hex_testbuf1",
+		.operation = "==",
+		.right_text = "hex_testbuf2",
+	};
+	struct kunit_mem_assert mem_assert = {
+		.assert = assert,
+		.text = &text,
+		.left_value = NULL,
+		.right_value = hex_testbuf2,
+		.size = sizeof(hex_testbuf1),
+	};
+
+	expected_stream = kunit_alloc_string_stream(test, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected_stream);
+	stream = kunit_alloc_string_stream(test, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, stream);
+
+	/* The left value is NULL */
+	validate_assert(kunit_mem_assert_format, test, &mem_assert.assert,
+			stream, 2, "hex_testbuf1", "is not null");
+
+	/* The right value is NULL, the left value is not NULL */
+	mem_assert.left_value = hex_testbuf1;
+	mem_assert.right_value = NULL;
+	validate_assert(kunit_mem_assert_format, test, &mem_assert.assert,
+			stream, 2, "hex_testbuf2", "is not null");
+
+	/* Both arguments are not null */
+	mem_assert.left_value = hex_testbuf1;
+	mem_assert.right_value = hex_testbuf2;
+
+	validate_assert(kunit_mem_assert_format, test, &mem_assert.assert,
+			stream, 3, "hex_testbuf1", "hex_testbuf2", "==");
+}
+
+static struct kunit_case assert_test_cases[] = {
+	KUNIT_CASE(kunit_test_is_literal),
+	KUNIT_CASE(kunit_test_is_str_literal),
+	KUNIT_CASE(kunit_test_assert_prologue),
+	KUNIT_CASE(kunit_test_assert_print_msg),
+	KUNIT_CASE(kunit_test_unary_assert_format),
+	KUNIT_CASE(kunit_test_ptr_not_err_assert_format),
+	KUNIT_CASE(kunit_test_binary_assert_format),
+	KUNIT_CASE(kunit_test_binary_ptr_assert_format),
+	KUNIT_CASE(kunit_test_binary_str_assert_format),
+	KUNIT_CASE(kunit_test_assert_hexdump),
+	KUNIT_CASE(kunit_test_mem_assert_format),
+	{}
+};
+
+static struct kunit_suite assert_test_suite = {
+	.name = "kunit-assert",
+	.test_cases = assert_test_cases,
+};
+
+kunit_test_suites(&assert_test_suite);