On Wed, 23 Oct 2024 11:19:40 -0400
Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx> wrote:
>
> > Looks like Mathieu patch broke bpf program contract somewhere.
>
> My patch series introduced this in the probe:
>
> #define __BPF_DECLARE_TRACE_SYSCALL(call, proto, args) \
> static notrace void \
> __bpf_trace_##call(void *__data, proto) \
> { \
> might_fault(); \
> preempt_disable_notrace(); \
Is the problem that we can call this function *after* the prog has been
freed? That is, the preempt_disable_notrace() here is meaningless.
Is there a way to add something here to make sure the program is still
valid? Like set a flag in the link structure?
(I don't know how BPF works well enough to know what is involved here,
so excuse me if this is totally off)
-- Steve
> CONCATENATE(bpf_trace_run, COUNT_ARGS(args))(__data, CAST_TO_U64(args)); \
> preempt_enable_notrace(); \
> }
>
