On Tue, 22 Oct 2019 22:24:01 +0200 Peter Zijlstra <pet...@infradead.org> wrote:
> On Mon, Oct 21, 2019 at 10:21:10PM -0400, Steven Rostedt wrote: > > On Fri, 18 Oct 2019 09:35:40 +0200 > > Peter Zijlstra <pet...@infradead.org> wrote: > > > > > Now that set_all_modules_text_*() is gone, nothing depends on the > > > relation between ->state = COMING and the protection state anymore. > > > This enables moving the protection changes later, such that the COMING > > > notifier callbacks can more easily modify the text. > > > > > > Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org> > > > Cc: Jessica Yu <j...@kernel.org> > > > --- > > > > This triggered the following bug: > > > > > The trace_event_define_fields_<event>() is defined in > > include/trace/trace_events.h and is an init function called by the > > trace_events event_create_dir() via the module notifier: > > MODULE_STATE_COMING > > The below seems to cure it; and seems to generate identical > events/*/format output (for my .config, with the exception of ID). > > It has just one section mismatch report that I'm too tired to look at > just now. > > I'm not particularly proud of the "__function__" hack, but it works :/ I > couldn't come up with anything else for [uk]probes which seem to have > dynamic fields and if we're having it then syscall_enter can also make > use of it, the syscall_metadata crud was going to be ugly otherwise. > > (also, win on LOC) > > After applying this series and this patch I triggered this: [ 1397.281889] BUG: kernel NULL pointer dereference, address: 0000000000000001 [ 1397.288896] #PF: supervisor read access in kernel mode [ 1397.294062] #PF: error_code(0x0000) - not-present page [ 1397.299192] PGD 0 P4D 0 [ 1397.301728] Oops: 0000 [#1] PREEMPT SMP PTI [ 1397.305908] CPU: 7 PID: 4252 Comm: ftracetest Not tainted 5.4.0-rc3-test+ #132 [ 1397.313114] Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016 [ 1397.322056] RIP: 0010:event_create_dir+0x26a/0x520 [ 1397.326841] Code: ff ff 5a 85 c0 75 37 44 03 7b 10 48 83 c3 20 4c 8b 13 4d 85 d2 0f 84 66 fe ff ff b9 0d 00 00 00 4c 89 d6 4c 89 f7 48 8b 53 08 <f3> a6 0f 97 c1 80 d9 00 84 c9 75 a5 48 89 ef e8 b2 d4 a3 00 85 c0 [ 1397.345558] RSP: 0018:ffffc90000a63d18 EFLAGS: 00010202 [ 1397.350775] RAX: 0000000000000000 RBX: ffffc90000a63d80 RCX: 000000000000000d [ 1397.357893] RDX: ffffffff811ccfac RSI: 0000000000000001 RDI: ffffffff8207c68a [ 1397.365006] RBP: ffff888114b1c750 R08: 0000000000000000 R09: ffff8881147561b0 [ 1397.372119] R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880b1d80528 [ 1397.379243] R13: ffff88811189aeb0 R14: ffffffff8207c68a R15: 00000000811d2d22 [ 1397.386365] FS: 00007f2567213740(0000) GS:ffff88811a9c0000(0000) knlGS:0000000000000000 [ 1397.394437] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1397.400174] CR2: 0000000000000001 CR3: 00000000b1f06005 CR4: 00000000001606e0 [ 1397.407297] Call Trace: [ 1397.409753] trace_add_event_call+0x6c/0xb0 [ 1397.413938] trace_probe_register_event_call+0x22/0x50 [ 1397.419071] trace_kprobe_create+0x65c/0xa20 [ 1397.423340] ? argv_split+0x99/0x130 [ 1397.426913] ? __kmalloc+0x1d4/0x2c0 [ 1397.430485] ? trace_kprobe_create+0xa20/0xa20 [ 1397.434922] ? trace_kprobe_create+0xa20/0xa20 [ 1397.439361] create_or_delete_trace_kprobe+0xd/0x30 [ 1397.444237] trace_run_command+0x72/0x90 [ 1397.448158] trace_parse_run_command+0xaf/0x131 [ 1397.452684] vfs_write+0xa5/0x1a0 [ 1397.455996] ksys_write+0x5c/0xd0 [ 1397.459312] do_syscall_64+0x48/0x120 [ 1397.462971] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 1397.468017] RIP: 0033:0x7f2567303ff8 By running tools/selftests/ftrace/ftracetest Crashed here: [33] Kprobe dynamic event - adding and removing [PASS] [34] Kprobe dynamic event - busy event check [PASS] [35] Kprobe event with comm arguments [FAIL] [36] Kprobe event string type argumentclient_loop: -- Steve