From bc754cc76d1bbc87be5d8b7eee05ceb0ae613bce Mon Sep 17 00:00:00 2001 From: "Masami Hiramatsu (Google)" Date: Tue, 20 Aug 2024 09:56:38 +0900 Subject: [PATCH] tracing: Fix memory leak in fgraph storage selftest With ftrace boot-time selftest, kmemleak reported some memory leaks in the new test case for function graph storage for multiple tracers. unreferenced object 0xffff888005060080 (size 32): comm "swapper/0", pid 1, jiffies 4294676440 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 20 10 06 05 80 88 ff ff ........ ....... 54 0c 1e 81 ff ff ff ff 00 00 00 00 00 00 00 00 T............... backtrace (crc 7c93416c): [<000000000238ee6f>] __kmalloc_cache_noprof+0x11f/0x2a0 [<0000000033d2b6c5>] enter_record+0xe8/0x150 [<0000000054c38424>] match_records+0x1cd/0x230 [<00000000c775b63d>] ftrace_set_hash+0xff/0x380 [<000000007bf7208c>] ftrace_set_filter+0x70/0x90 [<00000000a5c08dda>] test_graph_storage_multi+0x2e/0xf0 [<000000006ba028ca>] trace_selftest_startup_function_graph+0x1e8/0x260 [<00000000a715d3eb>] run_tracer_selftest+0x111/0x190 [<00000000395cbf90>] register_tracer+0xdf/0x1f0 [<0000000093e67f7b>] do_one_initcall+0x141/0x3b0 [<00000000c591b682>] do_initcall_level+0x82/0xa0 [<000000004e4c6600>] do_initcalls+0x43/0x70 [<0000000034f3c4e4>] kernel_init_freeable+0x170/0x1f0 [<00000000c7a5dab2>] kernel_init+0x1a/0x1a0 [<00000000ea105947>] ret_from_fork+0x3a/0x50 [<00000000a1932e84>] ret_from_fork_asm+0x1a/0x30 ... This means filter hash allocated for the fixtures are not correctly released after the test. Free those hash lists after tests are done and split the loop for initialize fixture and register fixture for rollback. Fixes: dd120af2d5f8 ("ftrace: Add multiple fgraph storage selftest") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/172411539857.28895.13119957560263401102.stgit@devnote2 Signed-off-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_selftest.c | 23 ++++++++++++++++++----- 1 file changed, 18 insertions(+), 5 deletions(-) diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 97f1e4bc47dc..c4ad7cd7e778 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -942,7 +942,7 @@ static __init int test_graph_storage_multi(void) { struct fgraph_fixture *fixture; bool printed = false; - int i, ret; + int i, j, ret; pr_cont("PASSED\n"); pr_info("Testing multiple fgraph storage on a function: "); @@ -953,22 +953,35 @@ static __init int test_graph_storage_multi(void) if (ret && ret != -ENODEV) { pr_cont("*Could not set filter* "); printed = true; - goto out; + goto out2; } + } + for (j = 0; j < ARRAY_SIZE(store_bytes); j++) { + fixture = &store_bytes[j]; ret = register_ftrace_graph(&fixture->gops); if (ret) { pr_warn("Failed to init store_bytes fgraph tracing\n"); printed = true; - goto out; + goto out1; } } DYN_FTRACE_TEST_NAME(); -out: +out1: + while (--j >= 0) { + fixture = &store_bytes[j]; + unregister_ftrace_graph(&fixture->gops); + + if (fixture->error_str && !printed) { + pr_cont("*** %s ***", fixture->error_str); + printed = true; + } + } +out2: while (--i >= 0) { fixture = &store_bytes[i]; - unregister_ftrace_graph(&fixture->gops); + ftrace_free_filter(&fixture->gops.ops); if (fixture->error_str && !printed) { pr_cont("*** %s ***", fixture->error_str);