From b6399cc789341fc49a0603fb7d388a4e50aca212 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Thu, 23 May 2019 19:50:34 -0400 Subject: [PATCH] tracing/kprobe: Do not run kprobe boot tests if kprobe_event is on cmdline When having kprobe trace event start up tests enabled and adding a kprobe_event on the kernel command line, it produced the following: trace_kprobe: Testing kprobe tracing: WARNING: CPU: 5 PID: 1 at kernel/trace/trace_kprobe.c:1724 kprobe_trace_self_tests_init+0x32d/0x36b Modules linked in: CPU: 5 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc1-test+ #249 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 RIP: 0010:kprobe_trace_self_tests_init+0x32d/0x36b Code: b7 e8 4f 8d a2 fe 85 c0 74 10 0f 0b 48 c7 c7 c8 1b 0d b7 ff c3 e8 19 af 99 fe 48 c7 c7 40 93 27 b7 e8 7f 1a a5 fe 85 c0 74 10 <0f> 0b 48 c7 c7 f8 1b 0d b7 ff c3 e8 f9 ae 9 a0 fe 85 RSP: 0018:ffffb36e40653e08 EFLAGS: 00010286 RAX: 00000000fffffff0 RBX: 0000000000000000 RCX: ffffb36e40653d5c RDX: 0000000000000000 RSI: ffffffffb72776e0 RDI: 0000000000000246 RBP: ffff98414fe58ff8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffff98415d8aa940 R12: 0000000000000000 R13: ffffffffb737c1b0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff98415ea80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f959ce741b8 CR3: 000000011a210002 CR4: 00000000001606e0 Call Trace: ? init_kprobe_trace+0x19e/0x19e ? do_early_param+0x8e/0x8e do_one_initcall+0x6f/0x2b4 ? do_early_param+0x8e/0x8e kernel_init_freeable+0x21d/0x2c6 ? rest_init+0x146/0x146 kernel_init+0xa/0x10a ret_from_fork+0x3a/0x50 ---[ end trace 488430c083a4c956 ]--- As with the trace events, if a trace event is set on the kernel command line, the trace events start up tests are suspended. The kprobe start up tests should do the same when a kprobe is enabled on the kernel command line. Signed-off-by: Steven Rostedt (VMware) --- kernel/trace/trace_kprobe.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 004fffd24ec1..7958da2fd922 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -25,6 +25,7 @@ /* Kprobe early definition from command line */ static char kprobe_boot_events_buf[COMMAND_LINE_SIZE] __initdata; +static bool kprobe_boot_events_enabled __initdata; static int __init set_kprobe_boot_events(char *str) { @@ -1538,6 +1539,8 @@ static __init void setup_boot_kprobe_events(void) ret = trace_run_command(cmd, create_or_delete_trace_kprobe); if (ret) pr_warn("Failed to add event(%d): %s\n", ret, cmd); + else + kprobe_boot_events_enabled = true; cmd = p; } @@ -1611,6 +1614,11 @@ static __init int kprobe_trace_self_tests_init(void) if (tracing_is_disabled()) return -ENODEV; + if (kprobe_boot_events_enabled) { + pr_info("Skipping kprobe tests due to kprobe_event on cmdline\n"); + return 0; + } + target = kprobe_trace_selftest_target; pr_info("Testing kprobe tracing: "); -- 2.45.2