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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-30 09:22:00 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-30 09:22:00 -0700 |
| commit | 034dd340b08be1f2f0477ad16131d609f9dbd53c (patch) | |
| tree | 2536f4b2d7893ccd916b5abdf3c454ad6edc03c2 /lib/test_vmalloc.c | |
| download | linux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.tar.gz linux-stable-034dd340b08be1f2f0477ad16131d609f9dbd53c.zip | |
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
Diffstat (limited to 'lib/test_vmalloc.c')
| -rw-r--r-- | lib/test_vmalloc.c | 706 |
1 files changed, 706 insertions, 0 deletions
diff --git a/lib/test_vmalloc.c b/lib/test_vmalloc.c new file mode 100644 index 000000000..b23f85e8f --- /dev/null +++ b/lib/test_vmalloc.c @@ -0,0 +1,706 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Test module for stress and analyze performance of vmalloc allocator. + * (C) 2018 Uladzislau Rezki (Sony) <urezki@gmail.com> + */ +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/vmalloc.h> +#include <linux/random.h> +#include <linux/kthread.h> +#include <linux/moduleparam.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/mm.h> +#include <linux/rcupdate.h> +#include <linux/srcu.h> +#include <linux/slab.h> + +#define __param(type, name, init, msg) \ + static type name = init; \ + module_param(name, type, 0444); \ + MODULE_PARM_DESC(name, msg) \ + +__param(int, nr_threads, 0, + "Number of workers to perform tests(min: 1 max: USHRT_MAX)"); + +__param(bool, sequential_test_order, false, + "Use sequential stress tests order"); + +__param(int, test_repeat_count, 1, + "Set test repeat counter"); + +__param(int, test_loop_count, 1000000, + "Set test loop counter"); + +__param(int, nr_pages, 0, + "Set number of pages for fix_size_alloc_test(default: 1)"); + +__param(bool, use_huge, false, + "Use vmalloc_huge in fix_size_alloc_test"); + +__param(int, run_test_mask, 7, + "Set tests specified in the mask.\n\n" + "\t\tid: 1, name: fix_size_alloc_test\n" + "\t\tid: 2, name: full_fit_alloc_test\n" + "\t\tid: 4, name: long_busy_list_alloc_test\n" + "\t\tid: 8, name: random_size_alloc_test\n" + "\t\tid: 16, name: fix_align_alloc_test\n" + "\t\tid: 32, name: random_size_align_alloc_test\n" + "\t\tid: 64, name: align_shift_alloc_test\n" + "\t\tid: 128, name: pcpu_alloc_test\n" + "\t\tid: 256, name: kvfree_rcu_1_arg_vmalloc_test\n" + "\t\tid: 512, name: kvfree_rcu_2_arg_vmalloc_test\n" + "\t\tid: 1024, name: vm_map_ram_test\n" + "\t\tid: 2048, name: no_block_alloc_test\n" + "\t\tid: 4096, name: vrealloc_test\n" + /* Add a new test case description here. */ +); + +__param(int, nr_pcpu_objects, 35000, + "Number of pcpu objects to allocate for pcpu_alloc_test"); + +/* + * This is for synchronization of setup phase. + */ +DEFINE_STATIC_SRCU(prepare_for_test_srcu); + +/* + * Completion tracking for worker threads. + */ +static DECLARE_COMPLETION(test_all_done_comp); +static atomic_t test_n_undone = ATOMIC_INIT(0); + +static inline void +test_report_one_done(void) +{ + if (atomic_dec_and_test(&test_n_undone)) + complete(&test_all_done_comp); +} + +static int random_size_align_alloc_test(void) +{ + unsigned long size, align; + unsigned int rnd; + void *ptr; + int i; + + for (i = 0; i < test_loop_count; i++) { + rnd = get_random_u8(); + + /* + * Maximum 1024 pages, if PAGE_SIZE is 4096. + */ + align = 1 << (rnd % 23); + + /* + * Maximum 10 pages. + */ + size = ((rnd % 10) + 1) * PAGE_SIZE; + + ptr = __vmalloc_node(size, align, GFP_KERNEL | __GFP_ZERO, 0, + __builtin_return_address(0)); + if (!ptr) + return -1; + + vfree(ptr); + } + + return 0; +} + +/* + * This test case is supposed to be failed. + */ +static int align_shift_alloc_test(void) +{ + unsigned long align; + void *ptr; + int i; + + for (i = 0; i < BITS_PER_LONG; i++) { + align = 1UL << i; + + ptr = __vmalloc_node(PAGE_SIZE, align, GFP_KERNEL|__GFP_ZERO, 0, + __builtin_return_address(0)); + if (!ptr) + return -1; + + vfree(ptr); + } + + return 0; +} + +static int fix_align_alloc_test(void) +{ + void *ptr; + int i; + + for (i = 0; i < test_loop_count; i++) { + ptr = __vmalloc_node(5 * PAGE_SIZE, THREAD_ALIGN << 1, + GFP_KERNEL | __GFP_ZERO, 0, + __builtin_return_address(0)); + if (!ptr) + return -1; + + vfree(ptr); + } + + return 0; +} + +static int random_size_alloc_test(void) +{ + unsigned int n; + void *p; + int i; + + for (i = 0; i < test_loop_count; i++) { + n = get_random_u32_inclusive(1, 100); + p = vmalloc(n * PAGE_SIZE); + + if (!p) + return -1; + + *((__u8 *)p) = 1; + vfree(p); + } + + return 0; +} + +static int long_busy_list_alloc_test(void) +{ + void *ptr_1, *ptr_2; + void **ptr; + int rv = -1; + int i; + + ptr = vmalloc(sizeof(void *) * 15000); + if (!ptr) + return rv; + + for (i = 0; i < 15000; i++) + ptr[i] = vmalloc(1 * PAGE_SIZE); + + for (i = 0; i < test_loop_count; i++) { + ptr_1 = vmalloc(100 * PAGE_SIZE); + if (!ptr_1) + goto leave; + + ptr_2 = vmalloc(1 * PAGE_SIZE); + if (!ptr_2) { + vfree(ptr_1); + goto leave; + } + + *((__u8 *)ptr_1) = 0; + *((__u8 *)ptr_2) = 1; + + vfree(ptr_1); + vfree(ptr_2); + } + + /* Success */ + rv = 0; + +leave: + for (i = 0; i < 15000; i++) + vfree(ptr[i]); + + vfree(ptr); + return rv; +} + +static int full_fit_alloc_test(void) +{ + void **ptr, **junk_ptr, *tmp; + int junk_length; + int rv = -1; + int i; + + junk_length = fls(num_online_cpus()); + junk_length *= (32 * 1024 * 1024 / PAGE_SIZE); + + ptr = vmalloc(sizeof(void *) * junk_length); + if (!ptr) + return rv; + + junk_ptr = vmalloc(sizeof(void *) * junk_length); + if (!junk_ptr) { + vfree(ptr); + return rv; + } + + for (i = 0; i < junk_length; i++) { + ptr[i] = vmalloc(1 * PAGE_SIZE); + junk_ptr[i] = vmalloc(1 * PAGE_SIZE); + } + + for (i = 0; i < junk_length; i++) + vfree(junk_ptr[i]); + + for (i = 0; i < test_loop_count; i++) { + tmp = vmalloc(1 * PAGE_SIZE); + + if (!tmp) + goto error; + + *((__u8 *)tmp) = 1; + vfree(tmp); + } + + /* Success */ + rv = 0; + +error: + for (i = 0; i < junk_length; i++) + vfree(ptr[i]); + + vfree(ptr); + vfree(junk_ptr); + + return rv; +} + +static int fix_size_alloc_test(void) +{ + void *ptr; + int i; + + for (i = 0; i < test_loop_count; i++) { + if (use_huge) + ptr = vmalloc_huge((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE, GFP_KERNEL); + else + ptr = vmalloc((nr_pages > 0 ? nr_pages:1) * PAGE_SIZE); + + if (!ptr) + return -1; + + *((__u8 *)ptr) = 0; + + vfree(ptr); + } + + return 0; +} + +static int no_block_alloc_test(void) +{ + void *ptr; + int i; + + for (i = 0; i < test_loop_count; i++) { + bool use_atomic = !!(get_random_u8() % 2); + gfp_t gfp = use_atomic ? GFP_ATOMIC : GFP_NOWAIT; + unsigned long size = (nr_pages > 0 ? nr_pages : 1) * PAGE_SIZE; + + preempt_disable(); + ptr = __vmalloc(size, gfp); + preempt_enable(); + + if (!ptr) + return -1; + + *((__u8 *)ptr) = 0; + vfree(ptr); + } + + return 0; +} + +static int +pcpu_alloc_test(void) +{ + int rv = 0; +#ifndef CONFIG_NEED_PER_CPU_KM + void __percpu **pcpu; + size_t size, align; + int i; + + pcpu = vmalloc(sizeof(void __percpu *) * nr_pcpu_objects); + if (!pcpu) + return -1; + + for (i = 0; i < nr_pcpu_objects; i++) { + size = get_random_u32_inclusive(1, PAGE_SIZE / 4); + + /* + * Maximum PAGE_SIZE + */ + align = 1 << get_random_u32_inclusive(1, PAGE_SHIFT - 1); + + pcpu[i] = __alloc_percpu(size, align); + if (!pcpu[i]) + rv = -1; + } + + for (i = 0; i < nr_pcpu_objects; i++) + free_percpu(pcpu[i]); + + vfree(pcpu); +#endif + return rv; +} + +struct test_kvfree_rcu { + struct rcu_head rcu; + unsigned char array[20]; +}; + +static int +kvfree_rcu_1_arg_vmalloc_test(void) +{ + struct test_kvfree_rcu *p; + int i; + + for (i = 0; i < test_loop_count; i++) { + p = vmalloc(1 * PAGE_SIZE); + if (!p) + return -1; + + p->array[0] = 'a'; + kvfree_rcu_mightsleep(p); + } + + return 0; +} + +static int +kvfree_rcu_2_arg_vmalloc_test(void) +{ + struct test_kvfree_rcu *p; + int i; + + for (i = 0; i < test_loop_count; i++) { + p = vmalloc(1 * PAGE_SIZE); + if (!p) + return -1; + + p->array[0] = 'a'; + kvfree_rcu(p, rcu); + } + + return 0; +} + +static int +vm_map_ram_test(void) +{ + unsigned long nr_allocated; + unsigned int map_nr_pages; + unsigned char *v_ptr; + struct page **pages; + int i; + + map_nr_pages = nr_pages > 0 ? nr_pages:1; + pages = kzalloc_objs(struct page *, map_nr_pages); + if (!pages) + return -1; + + nr_allocated = alloc_pages_bulk(GFP_KERNEL, map_nr_pages, pages); + if (nr_allocated != map_nr_pages) + goto cleanup; + + /* Run the test loop. */ + for (i = 0; i < test_loop_count; i++) { + v_ptr = vm_map_ram(pages, map_nr_pages, NUMA_NO_NODE); + *v_ptr = 'a'; + vm_unmap_ram(v_ptr, map_nr_pages); + } + +cleanup: + for (i = 0; i < nr_allocated; i++) + __free_page(pages[i]); + + kfree(pages); + + /* 0 indicates success. */ + return nr_allocated != map_nr_pages; +} + +static int vrealloc_test(void) +{ + void *ptr, *tmp; + int i; + + for (i = 0; i < test_loop_count; i++) { + int err = -1; + + ptr = vrealloc(NULL, PAGE_SIZE, GFP_KERNEL); + if (!ptr) + return -1; + + *((__u8 *)ptr) = 'a'; + + /* Grow: beyond allocated pages, triggers full realloc. */ + tmp = vrealloc(ptr, 4 * PAGE_SIZE, GFP_KERNEL); + if (!tmp) + goto error; + ptr = tmp; + + if (*((__u8 *)ptr) != 'a') + goto error; + + /* Shrink: crosses page boundary, frees tail pages. */ + tmp = vrealloc(ptr, PAGE_SIZE, GFP_KERNEL); + if (!tmp) + goto error; + ptr = tmp; + + if (*((__u8 *)ptr) != 'a') + goto error; + + /* Shrink: within same page, no page freeing. */ + tmp = vrealloc(ptr, PAGE_SIZE / 2, GFP_KERNEL); + if (!tmp) + goto error; + ptr = tmp; + + if (*((__u8 *)ptr) != 'a') + goto error; + + /* Grow: within allocated page, in-place, no realloc. */ + tmp = vrealloc(ptr, PAGE_SIZE, GFP_KERNEL); + if (!tmp) + goto error; + ptr = tmp; + + if (*((__u8 *)ptr) != 'a') + goto error; + + err = 0; +error: + vfree(ptr); + if (err) + return err; + } + + return 0; +} + +struct test_case_desc { + const char *test_name; + int (*test_func)(void); + bool xfail; +}; + +static struct test_case_desc test_case_array[] = { + { "fix_size_alloc_test", fix_size_alloc_test, }, + { "full_fit_alloc_test", full_fit_alloc_test, }, + { "long_busy_list_alloc_test", long_busy_list_alloc_test, }, + { "random_size_alloc_test", random_size_alloc_test, }, + { "fix_align_alloc_test", fix_align_alloc_test, }, + { "random_size_align_alloc_test", random_size_align_alloc_test, }, + { "align_shift_alloc_test", align_shift_alloc_test, true }, + { "pcpu_alloc_test", pcpu_alloc_test, }, + { "kvfree_rcu_1_arg_vmalloc_test", kvfree_rcu_1_arg_vmalloc_test, }, + { "kvfree_rcu_2_arg_vmalloc_test", kvfree_rcu_2_arg_vmalloc_test, }, + { "vm_map_ram_test", vm_map_ram_test, }, + { "no_block_alloc_test", no_block_alloc_test, true }, + { "vrealloc_test", vrealloc_test, }, + /* Add a new test case here. */ +}; + +struct test_case_data { + int test_failed; + int test_xfailed; + int test_passed; + u64 time; +}; + +static struct test_driver { + struct task_struct *task; + struct test_case_data data[ARRAY_SIZE(test_case_array)]; + + unsigned long start; + unsigned long stop; +} *tdriver; + +static void shuffle_array(int *arr, int n) +{ + int i, j; + + for (i = n - 1; i > 0; i--) { + /* Cut the range. */ + j = get_random_u32_below(i); + + /* Swap indexes. */ + swap(arr[i], arr[j]); + } +} + +static int test_func(void *private) +{ + struct test_driver *t = private; + int random_array[ARRAY_SIZE(test_case_array)]; + int index, i, j, ret; + ktime_t kt; + u64 delta; + + for (i = 0; i < ARRAY_SIZE(test_case_array); i++) + random_array[i] = i; + + if (!sequential_test_order) + shuffle_array(random_array, ARRAY_SIZE(test_case_array)); + + /* + * Block until initialization is done. + */ + synchronize_srcu(&prepare_for_test_srcu); + + t->start = get_cycles(); + for (i = 0; i < ARRAY_SIZE(test_case_array); i++) { + index = random_array[i]; + + /* + * Skip tests if run_test_mask has been specified. + */ + if (!((run_test_mask & (1 << index)) >> index)) + continue; + kt = ktime_get(); + for (j = 0; j < test_repeat_count; j++) { + ret = test_case_array[index].test_func(); + + if (!ret) + t->data[index].test_passed++; + else if (ret && test_case_array[index].xfail) + t->data[index].test_xfailed++; + else + t->data[index].test_failed++; + } + + /* + * Take an average time that test took. + */ + delta = (u64) ktime_us_delta(ktime_get(), kt); + do_div(delta, (u32) test_repeat_count); + + t->data[index].time = delta; + } + t->stop = get_cycles(); + test_report_one_done(); + + /* + * Wait for the kthread_stop() call. + */ + while (!kthread_should_stop()) + msleep(10); + + return 0; +} + +static int +init_test_configuration(void) +{ + /* + * A maximum number of workers is defined as hard-coded + * value and set to USHRT_MAX. We add such gap just in + * case and for potential heavy stressing. + */ + nr_threads = clamp(nr_threads, 1, (int) USHRT_MAX); + + /* Allocate the space for test instances. */ + tdriver = kvzalloc_objs(*tdriver, nr_threads); + if (tdriver == NULL) + return -1; + + if (test_repeat_count <= 0) + test_repeat_count = 1; + + if (test_loop_count <= 0) + test_loop_count = 1; + + return 0; +} + +static void do_concurrent_test(void) +{ + int i, ret, idx; + + /* + * Set some basic configurations plus sanity check. + */ + ret = init_test_configuration(); + if (ret < 0) + return; + + /* + * Put on hold all workers. + */ + idx = srcu_read_lock(&prepare_for_test_srcu); + + for (i = 0; i < nr_threads; i++) { + struct test_driver *t = &tdriver[i]; + + t->task = kthread_run(test_func, t, "vmalloc_test/%d", i); + + if (!IS_ERR(t->task)) + /* Success. */ + atomic_inc(&test_n_undone); + else + pr_err("Failed to start %d kthread\n", i); + } + + /* + * Now let the workers do their job. + */ + srcu_read_unlock(&prepare_for_test_srcu, idx); + + /* + * Sleep quiet until all workers are done with 1 second + * interval. Since the test can take a lot of time we + * can run into a stack trace of the hung task. That is + * why we go with completion_timeout and HZ value. + */ + do { + ret = wait_for_completion_timeout(&test_all_done_comp, HZ); + } while (!ret); + + for (i = 0; i < nr_threads; i++) { + struct test_driver *t = &tdriver[i]; + int j; + + if (!IS_ERR(t->task)) + kthread_stop(t->task); + + for (j = 0; j < ARRAY_SIZE(test_case_array); j++) { + if (!((run_test_mask & (1 << j)) >> j)) + continue; + + pr_info( + "Summary: %s passed: %d failed: %d xfailed: %d repeat: %d loops: %d avg: %llu usec\n", + test_case_array[j].test_name, + t->data[j].test_passed, + t->data[j].test_failed, + t->data[j].test_xfailed, + test_repeat_count, test_loop_count, + t->data[j].time); + } + + pr_info("All test took worker%d=%lu cycles\n", + i, t->stop - t->start); + } + + kvfree(tdriver); +} + +static int __init vmalloc_test_init(void) +{ + do_concurrent_test(); + /* Fail will directly unload the module */ + return IS_BUILTIN(CONFIG_TEST_VMALLOC) ? 0:-EAGAIN; +} + +#ifdef MODULE +module_init(vmalloc_test_init) +#else +late_initcall(vmalloc_test_init); +#endif + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Uladzislau Rezki"); +MODULE_DESCRIPTION("vmalloc test module"); |
