From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace 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 --- lib/tests/memcpy_kunit.c | 514 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 514 insertions(+) create mode 100644 lib/tests/memcpy_kunit.c (limited to 'lib/tests/memcpy_kunit.c') diff --git a/lib/tests/memcpy_kunit.c b/lib/tests/memcpy_kunit.c new file mode 100644 index 000000000..d36933554 --- /dev/null +++ b/lib/tests/memcpy_kunit.c @@ -0,0 +1,514 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test cases for memcpy(), memmove(), and memset(). + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct some_bytes { + union { + u8 data[32]; + struct { + u32 one; + u16 two; + u8 three; + /* 1 byte hole */ + u32 four[4]; + }; + }; +}; + +#define check(instance, v) do { \ + BUILD_BUG_ON(sizeof(instance.data) != 32); \ + for (size_t i = 0; i < sizeof(instance.data); i++) { \ + KUNIT_ASSERT_EQ_MSG(test, instance.data[i], v, \ + "line %d: '%s' not initialized to 0x%02x @ %zu (saw 0x%02x)\n", \ + __LINE__, #instance, v, i, instance.data[i]); \ + } \ +} while (0) + +#define compare(name, one, two) do { \ + BUILD_BUG_ON(sizeof(one) != sizeof(two)); \ + for (size_t i = 0; i < sizeof(one); i++) { \ + KUNIT_EXPECT_EQ_MSG(test, one.data[i], two.data[i], \ + "line %d: %s.data[%zu] (0x%02x) != %s.data[%zu] (0x%02x)\n", \ + __LINE__, #one, i, one.data[i], #two, i, two.data[i]); \ + } \ + kunit_info(test, "ok: " TEST_OP "() " name "\n"); \ +} while (0) + +static void memcpy_test(struct kunit *test) +{ +#define TEST_OP "memcpy" + struct some_bytes control = { + .data = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + }, + }; + struct some_bytes zero = { }; + struct some_bytes middle = { + .data = { 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + }, + }; + struct some_bytes three = { + .data = { 0x00, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x00, 0x00, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, 0x20, + }, + }; + struct some_bytes dest = { }; + int count; + u8 *ptr; + + /* Verify static initializers. */ + check(control, 0x20); + check(zero, 0); + compare("static initializers", dest, zero); + + /* Verify assignment. */ + dest = control; + compare("direct assignment", dest, control); + + /* Verify complete overwrite. */ + memcpy(dest.data, zero.data, sizeof(dest.data)); + compare("complete overwrite", dest, zero); + + /* Verify middle overwrite. */ + dest = control; + memcpy(dest.data + 12, zero.data, 7); + compare("middle overwrite", dest, middle); + + /* Verify argument side-effects aren't repeated. */ + dest = control; + ptr = dest.data; + count = 1; + memcpy(ptr++, zero.data, count++); + ptr += 8; + memcpy(ptr++, zero.data, count++); + compare("argument side-effects", dest, three); +#undef TEST_OP +} + +static unsigned char larger_array [2048]; + +static void memmove_test(struct kunit *test) +{ +#define TEST_OP "memmove" + struct some_bytes control = { + .data = { 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + }, + }; + struct some_bytes zero = { }; + struct some_bytes middle = { + .data = { 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + }, + }; + struct some_bytes five = { + .data = { 0x00, 0x00, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x00, 0x00, 0x00, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + }, + }; + struct some_bytes overlap = { + .data = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, + 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + }, + }; + struct some_bytes overlap_expected = { + .data = { 0x00, 0x01, 0x00, 0x01, 0x02, 0x03, 0x04, 0x07, + 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, 0x99, + }, + }; + struct some_bytes dest = { }; + int count; + u8 *ptr; + + /* Verify static initializers. */ + check(control, 0x99); + check(zero, 0); + compare("static initializers", zero, dest); + + /* Verify assignment. */ + dest = control; + compare("direct assignment", dest, control); + + /* Verify complete overwrite. */ + memmove(dest.data, zero.data, sizeof(dest.data)); + compare("complete overwrite", dest, zero); + + /* Verify middle overwrite. */ + dest = control; + memmove(dest.data + 12, zero.data, 7); + compare("middle overwrite", dest, middle); + + /* Verify argument side-effects aren't repeated. */ + dest = control; + ptr = dest.data; + count = 2; + memmove(ptr++, zero.data, count++); + ptr += 9; + memmove(ptr++, zero.data, count++); + compare("argument side-effects", dest, five); + + /* Verify overlapping overwrite is correct. */ + ptr = &overlap.data[2]; + memmove(ptr, overlap.data, 5); + compare("overlapping write", overlap, overlap_expected); + + /* Verify larger overlapping moves. */ + larger_array[256] = 0xAAu; + /* + * Test a backwards overlapping memmove first. 256 and 1024 are + * important for i386 to use rep movsl. + */ + memmove(larger_array, larger_array + 256, 1024); + KUNIT_ASSERT_EQ(test, larger_array[0], 0xAAu); + KUNIT_ASSERT_EQ(test, larger_array[256], 0x00); + KUNIT_ASSERT_NULL(test, + memchr(larger_array + 1, 0xaa, ARRAY_SIZE(larger_array) - 1)); + /* Test a forwards overlapping memmove. */ + larger_array[0] = 0xBBu; + memmove(larger_array + 256, larger_array, 1024); + KUNIT_ASSERT_EQ(test, larger_array[0], 0xBBu); + KUNIT_ASSERT_EQ(test, larger_array[256], 0xBBu); + KUNIT_ASSERT_NULL(test, memchr(larger_array + 1, 0xBBu, 256 - 1)); + KUNIT_ASSERT_NULL(test, + memchr(larger_array + 257, 0xBBu, ARRAY_SIZE(larger_array) - 257)); +#undef TEST_OP +} + +static void memset_test(struct kunit *test) +{ +#define TEST_OP "memset" + struct some_bytes control = { + .data = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + }, + }; + struct some_bytes complete = { + .data = { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, + }, + }; + struct some_bytes middle = { + .data = { 0x30, 0x30, 0x30, 0x30, 0x31, 0x31, 0x31, 0x31, + 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, 0x31, + 0x31, 0x31, 0x31, 0x31, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + }, + }; + struct some_bytes three = { + .data = { 0x60, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x61, 0x61, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + }, + }; + struct some_bytes after = { + .data = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x72, + 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, + 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, + 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, 0x72, + }, + }; + struct some_bytes startat = { + .data = { 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, 0x30, + 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, + 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, + 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, 0x79, + }, + }; + struct some_bytes dest = { }; + int count, value; + u8 *ptr; + + /* Verify static initializers. */ + check(control, 0x30); + check(dest, 0); + + /* Verify assignment. */ + dest = control; + compare("direct assignment", dest, control); + + /* Verify complete overwrite. */ + memset(dest.data, 0xff, sizeof(dest.data)); + compare("complete overwrite", dest, complete); + + /* Verify middle overwrite. */ + dest = control; + memset(dest.data + 4, 0x31, 16); + compare("middle overwrite", dest, middle); + + /* Verify argument side-effects aren't repeated. */ + dest = control; + ptr = dest.data; + value = 0x60; + count = 1; + memset(ptr++, value++, count++); + ptr += 8; + memset(ptr++, value++, count++); + compare("argument side-effects", dest, three); + + /* Verify memset_after() */ + dest = control; + memset_after(&dest, 0x72, three); + compare("memset_after()", dest, after); + + /* Verify memset_startat() */ + dest = control; + memset_startat(&dest, 0x79, four); + compare("memset_startat()", dest, startat); +#undef TEST_OP +} + +static u8 large_src[1024]; +static u8 large_dst[2048]; +static const u8 large_zero[2048]; + +static void set_random_nonzero(struct kunit *test, u8 *byte) +{ + int failed_rng = 0; + + while (*byte == 0) { + get_random_bytes(byte, 1); + KUNIT_ASSERT_LT_MSG(test, failed_rng++, 100, + "Is the RNG broken?"); + } +} + +static void init_large(struct kunit *test) +{ + /* Get many bit patterns. */ + get_random_bytes(large_src, ARRAY_SIZE(large_src)); + + /* Make sure we have non-zero edges. */ + set_random_nonzero(test, &large_src[0]); + set_random_nonzero(test, &large_src[ARRAY_SIZE(large_src) - 1]); + + /* Explicitly zero the entire destination. */ + memset(large_dst, 0, ARRAY_SIZE(large_dst)); +} + +/* + * Instead of an indirect function call for "copy" or a giant macro, + * use a bool to pick memcpy or memmove. + */ +static void copy_large_test(struct kunit *test, bool use_memmove) +{ + init_large(test); + + /* Copy a growing number of non-overlapping bytes ... */ + for (int bytes = 1; bytes <= ARRAY_SIZE(large_src); bytes++) { + /* Over a shifting destination window ... */ + for (int offset = 0; offset < ARRAY_SIZE(large_src); offset++) { + int right_zero_pos = offset + bytes; + int right_zero_size = ARRAY_SIZE(large_dst) - right_zero_pos; + + /* Copy! */ + if (use_memmove) + memmove(large_dst + offset, large_src, bytes); + else + memcpy(large_dst + offset, large_src, bytes); + + /* Did we touch anything before the copy area? */ + KUNIT_ASSERT_EQ_MSG(test, + memcmp(large_dst, large_zero, offset), 0, + "with size %d at offset %d", bytes, offset); + /* Did we touch anything after the copy area? */ + KUNIT_ASSERT_EQ_MSG(test, + memcmp(&large_dst[right_zero_pos], large_zero, right_zero_size), 0, + "with size %d at offset %d", bytes, offset); + + /* Are we byte-for-byte exact across the copy? */ + KUNIT_ASSERT_EQ_MSG(test, + memcmp(large_dst + offset, large_src, bytes), 0, + "with size %d at offset %d", bytes, offset); + + /* Zero out what we copied for the next cycle. */ + memset(large_dst + offset, 0, bytes); + } + /* Avoid stall warnings if this loop gets slow. */ + cond_resched(); + } +} + +static void memcpy_large_test(struct kunit *test) +{ + copy_large_test(test, false); +} + +static void memmove_large_test(struct kunit *test) +{ + copy_large_test(test, true); +} + +/* + * On the assumption that boundary conditions are going to be the most + * sensitive, instead of taking a full step (inc) each iteration, + * take single index steps for at least the first "inc"-many indexes + * from the "start" and at least the last "inc"-many indexes before + * the "end". When in the middle, take full "inc"-wide steps. For + * example, calling next_step(idx, 1, 15, 3) with idx starting at 0 + * would see the following pattern: 1 2 3 4 7 10 11 12 13 14 15. + */ +static int next_step(int idx, int start, int end, int inc) +{ + start += inc; + end -= inc; + + if (idx < start || idx + inc > end) + inc = 1; + return idx + inc; +} + +static void inner_loop(struct kunit *test, int bytes, int d_off, int s_off) +{ + int left_zero_pos, left_zero_size; + int right_zero_pos, right_zero_size; + int src_pos, src_orig_pos, src_size; + int pos; + + /* Place the source in the destination buffer. */ + memcpy(&large_dst[s_off], large_src, bytes); + + /* Copy to destination offset. */ + memmove(&large_dst[d_off], &large_dst[s_off], bytes); + + /* Make sure destination entirely matches. */ + KUNIT_ASSERT_EQ_MSG(test, memcmp(&large_dst[d_off], large_src, bytes), 0, + "with size %d at src offset %d and dest offset %d", + bytes, s_off, d_off); + + /* Calculate the expected zero spans. */ + if (s_off < d_off) { + left_zero_pos = 0; + left_zero_size = s_off; + + right_zero_pos = d_off + bytes; + right_zero_size = ARRAY_SIZE(large_dst) - right_zero_pos; + + src_pos = s_off; + src_orig_pos = 0; + src_size = d_off - s_off; + } else { + left_zero_pos = 0; + left_zero_size = d_off; + + right_zero_pos = s_off + bytes; + right_zero_size = ARRAY_SIZE(large_dst) - right_zero_pos; + + src_pos = d_off + bytes; + src_orig_pos = src_pos - s_off; + src_size = right_zero_pos - src_pos; + } + + /* Check non-overlapping source is unchanged.*/ + KUNIT_ASSERT_EQ_MSG(test, + memcmp(&large_dst[src_pos], &large_src[src_orig_pos], src_size), 0, + "with size %d at src offset %d and dest offset %d", + bytes, s_off, d_off); + + /* Check leading buffer contents are zero. */ + KUNIT_ASSERT_EQ_MSG(test, + memcmp(&large_dst[left_zero_pos], large_zero, left_zero_size), 0, + "with size %d at src offset %d and dest offset %d", + bytes, s_off, d_off); + /* Check trailing buffer contents are zero. */ + KUNIT_ASSERT_EQ_MSG(test, + memcmp(&large_dst[right_zero_pos], large_zero, right_zero_size), 0, + "with size %d at src offset %d and dest offset %d", + bytes, s_off, d_off); + + /* Zero out everything not already zeroed.*/ + pos = left_zero_pos + left_zero_size; + memset(&large_dst[pos], 0, right_zero_pos - pos); +} + +static void memmove_overlap_test(struct kunit *test) +{ + /* + * Running all possible offset and overlap combinations takes a + * very long time. Instead, only check up to 128 bytes offset + * into the destination buffer (which should result in crossing + * cachelines), with a step size of 1 through 7 to try to skip some + * redundancy. + */ + static const int offset_max = 128; /* less than ARRAY_SIZE(large_src); */ + static const int bytes_step = 7; + static const int window_step = 7; + + static const int bytes_start = 1; + static const int bytes_end = ARRAY_SIZE(large_src) + 1; + + init_large(test); + + /* Copy a growing number of overlapping bytes ... */ + for (int bytes = bytes_start; bytes < bytes_end; + bytes = next_step(bytes, bytes_start, bytes_end, bytes_step)) { + + /* Over a shifting destination window ... */ + for (int d_off = 0; d_off < offset_max; d_off++) { + int s_start = max(d_off - bytes, 0); + int s_end = min_t(int, d_off + bytes, ARRAY_SIZE(large_src)); + + /* Over a shifting source window ... */ + for (int s_off = s_start; s_off < s_end; + s_off = next_step(s_off, s_start, s_end, window_step)) + inner_loop(test, bytes, d_off, s_off); + + /* Avoid stall warnings. */ + cond_resched(); + } + } +} + +static struct kunit_case memcpy_test_cases[] = { + KUNIT_CASE(memset_test), + KUNIT_CASE(memcpy_test), + KUNIT_CASE_SLOW(memcpy_large_test), + KUNIT_CASE_SLOW(memmove_test), + KUNIT_CASE_SLOW(memmove_large_test), + KUNIT_CASE_SLOW(memmove_overlap_test), + {} +}; + +static struct kunit_suite memcpy_test_suite = { + .name = "memcpy", + .test_cases = memcpy_test_cases, +}; + +kunit_test_suite(memcpy_test_suite); + +MODULE_DESCRIPTION("test cases for memcpy(), memmove(), and memset()"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1