diff options
| author | Rafael Mendonca <rafaelmendsr@gmail.com> | 2022-11-18 10:15:34 +0900 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2022-11-18 10:15:34 +0900 |
| commit | 342a4a2f99431ee3c72ef5cfff6449ccf2abd346 (patch) | |
| tree | 977c26b17f8954335f48426a44fd04f3d23c8ba6 /kernel | |
| parent | 5dd7caf0bdc5d0bae7cf9776b4d739fb09bd5ebb (diff) | |
tracing/eprobe: Fix warning in filter creation
The filter pointer (filterp) passed to create_filter() function must be a
pointer that references a NULL pointer, otherwise, we get a warning when
adding a filter option to the event probe:
root@localhost:/sys/kernel/tracing# echo 'e:egroup/stat_runtime_4core sched/sched_stat_runtime \
runtime=$runtime:u32 if cpu < 4' >> dynamic_events
[ 5034.340439] ------------[ cut here ]------------
[ 5034.341258] WARNING: CPU: 0 PID: 223 at kernel/trace/trace_events_filter.c:1939 create_filter+0x1db/0x250
[...] stripped
[ 5034.345518] RIP: 0010:create_filter+0x1db/0x250
[...] stripped
[ 5034.351604] Call Trace:
[ 5034.351803] <TASK>
[ 5034.351959] ? process_preds+0x1b40/0x1b40
[ 5034.352241] ? rcu_read_lock_bh_held+0xd0/0xd0
[ 5034.352604] ? kasan_set_track+0x29/0x40
[ 5034.352904] ? kasan_save_alloc_info+0x1f/0x30
[ 5034.353264] create_event_filter+0x38/0x50
[ 5034.353573] __trace_eprobe_create+0x16f4/0x1d20
[ 5034.353964] ? eprobe_dyn_event_release+0x360/0x360
[ 5034.354363] ? mark_held_locks+0xa6/0xf0
[ 5034.354684] ? _raw_spin_unlock_irqrestore+0x35/0x60
[ 5034.355105] ? trace_hardirqs_on+0x41/0x120
[ 5034.355417] ? _raw_spin_unlock_irqrestore+0x35/0x60
[ 5034.355751] ? __create_object+0x5b7/0xcf0
[ 5034.356027] ? lock_is_held_type+0xaf/0x120
[ 5034.356362] ? rcu_read_lock_bh_held+0xb0/0xd0
[ 5034.356716] ? rcu_read_lock_bh_held+0xd0/0xd0
[ 5034.357084] ? kasan_set_track+0x29/0x40
[ 5034.357411] ? kasan_save_alloc_info+0x1f/0x30
[ 5034.357715] ? __kasan_kmalloc+0xb8/0xc0
[ 5034.357985] ? write_comp_data+0x2f/0x90
[ 5034.358302] ? __sanitizer_cov_trace_pc+0x25/0x60
[ 5034.358691] ? argv_split+0x381/0x460
[ 5034.358949] ? write_comp_data+0x2f/0x90
[ 5034.359240] ? eprobe_dyn_event_release+0x360/0x360
[ 5034.359620] trace_probe_create+0xf6/0x110
[ 5034.359940] ? trace_probe_match_command_args+0x240/0x240
[ 5034.360376] eprobe_dyn_event_create+0x21/0x30
[ 5034.360709] create_dyn_event+0xf3/0x1a0
[ 5034.360983] trace_parse_run_command+0x1a9/0x2e0
[ 5034.361297] ? dyn_event_release+0x500/0x500
[ 5034.361591] dyn_event_write+0x39/0x50
[ 5034.361851] vfs_write+0x311/0xe50
[ 5034.362091] ? dyn_event_seq_next+0x40/0x40
[ 5034.362376] ? kernel_write+0x5b0/0x5b0
[ 5034.362637] ? write_comp_data+0x2f/0x90
[ 5034.362937] ? __sanitizer_cov_trace_pc+0x25/0x60
[ 5034.363258] ? ftrace_syscall_enter+0x544/0x840
[ 5034.363563] ? write_comp_data+0x2f/0x90
[ 5034.363837] ? __sanitizer_cov_trace_pc+0x25/0x60
[ 5034.364156] ? write_comp_data+0x2f/0x90
[ 5034.364468] ? write_comp_data+0x2f/0x90
[ 5034.364770] ksys_write+0x158/0x2a0
[ 5034.365022] ? __ia32_sys_read+0xc0/0xc0
[ 5034.365344] __x64_sys_write+0x7c/0xc0
[ 5034.365669] ? syscall_enter_from_user_mode+0x53/0x70
[ 5034.366084] do_syscall_64+0x60/0x90
[ 5034.366356] entry_SYSCALL_64_after_hwframe+0x63/0xcd
[ 5034.366767] RIP: 0033:0x7ff0b43938f3
[...] stripped
[ 5034.371892] </TASK>
[ 5034.374720] ---[ end trace 0000000000000000 ]---
Link: https://lore.kernel.org/all/20221108202148.1020111-1-rafaelmendsr@gmail.com/
Fixes: 752be5c5c910 ("tracing/eprobe: Add eprobe filter support")
Signed-off-by: Rafael Mendonca <rafaelmendsr@gmail.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/trace_eprobe.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace_eprobe.c b/kernel/trace/trace_eprobe.c index fe4833a7b7b3..e888446d80fa 100644 --- a/kernel/trace/trace_eprobe.c +++ b/kernel/trace/trace_eprobe.c @@ -901,7 +901,7 @@ static int trace_eprobe_tp_update_arg(struct trace_eprobe *ep, const char *argv[ static int trace_eprobe_parse_filter(struct trace_eprobe *ep, int argc, const char *argv[]) { - struct event_filter *dummy; + struct event_filter *dummy = NULL; int i, ret, len = 0; char *p; |