diff options
| author | Delyan Kratunov <delyank@fb.com> | 2022-05-11 18:28:36 +0000 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2022-05-12 00:37:11 +0200 |
| commit | 9c2136be0878c88c53dea26943ce40bb03ad8d8d (patch) | |
| tree | 63ea6e07f82cc650db9a4d14d87f4b82df34a9c6 /kernel/trace/fgraph.c | |
| parent | c5eb0a61238dd6faf37f58c9ce61c9980aaffd7a (diff) | |
sched/tracing: Append prev_state to tp args instead
Commit fa2c3254d7cf (sched/tracing: Don't re-read p->state when emitting
sched_switch event, 2022-01-20) added a new prev_state argument to the
sched_switch tracepoint, before the prev task_struct pointer.
This reordering of arguments broke BPF programs that use the raw
tracepoint (e.g. tp_btf programs). The type of the second argument has
changed and existing programs that assume a task_struct* argument
(e.g. for bpf_task_storage access) will now fail to verify.
If we instead append the new argument to the end, all existing programs
would continue to work and can conditionally extract the prev_state
argument on supported kernel versions.
Fixes: fa2c3254d7cf (sched/tracing: Don't re-read p->state when emitting sched_switch event, 2022-01-20)
Signed-off-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/c8a6930dfdd58a4a5755fc01732675472979732b.camel@fb.com
Diffstat (limited to 'kernel/trace/fgraph.c')
| -rw-r--r-- | kernel/trace/fgraph.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index 8f4fb328133a..a7e84c8543cb 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -404,9 +404,9 @@ free: static void ftrace_graph_probe_sched_switch(void *ignore, bool preempt, - unsigned int prev_state, struct task_struct *prev, - struct task_struct *next) + struct task_struct *next, + unsigned int prev_state) { unsigned long long timestamp; int index; |