From 9c2136be0878c88c53dea26943ce40bb03ad8d8d Mon Sep 17 00:00:00 2001 From: Delyan Kratunov Date: Wed, 11 May 2022 18:28:36 +0000 Subject: 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 Signed-off-by: Peter Zijlstra (Intel) Acked-by: Steven Rostedt (Google) Link: https://lkml.kernel.org/r/c8a6930dfdd58a4a5755fc01732675472979732b.camel@fb.com --- kernel/trace/fgraph.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/trace/fgraph.c') 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; -- cgit