On Wed, Oct 01, 2025 at 03:20:25AM +0100, [email protected] wrote: > > v1->v2: Fix race analysis (per Masami) - kprobe arms in class->reg(). > v2->v3: Adopt RELEASE/ACQUIRE semantics per Peter/John's suggestions, > aligning with Steven's clarification on barrier purposes. > v3->v4: Introduce load_flag() (Masami) and optimize barrier usage in > checks/clear (Peter).
Stuff like this ought to go below the --- such that git-am and similar tools throw it out. > Signed-off-by: Yuan Chen <[email protected]> > --- > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index ccae62d4fb91..b1b793b8f191 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -1813,14 +1813,15 @@ static int kprobe_register(struct trace_event_call > *event, > static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) > { > struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); > + unsigned int flags = trace_probe_load_flag(&tk->tp); > int ret = 0; > > raw_cpu_inc(*tk->nhit); > > - if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) > + if (flags & TP_FLAG_TRACE) > kprobe_trace_func(tk, regs); > #ifdef CONFIG_PERF_EVENTS > - if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) > + if (flags & TP_FLAG_PROFILE) > ret = kprobe_perf_func(tk, regs); > #endif > return ret; > @@ -1832,6 +1833,7 @@ kretprobe_dispatcher(struct kretprobe_instance *ri, > struct pt_regs *regs) > { > struct kretprobe *rp = get_kretprobe(ri); > struct trace_kprobe *tk; > + unsigned int flags; > > /* > * There is a small chance that get_kretprobe(ri) returns NULL when > @@ -1844,10 +1846,11 @@ kretprobe_dispatcher(struct kretprobe_instance *ri, > struct pt_regs *regs) > tk = container_of(rp, struct trace_kprobe, rp); > raw_cpu_inc(*tk->nhit); > > - if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) > + flags = trace_probe_load_flag(&tk->tp); > + if (flags & TP_FLAG_TRACE) > kretprobe_trace_func(tk, ri, regs); > #ifdef CONFIG_PERF_EVENTS > - if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) > + if (flags & TP_FLAG_PROFILE) > kretprobe_perf_func(tk, ri, regs); > #endif > return 0; /* We don't tweak kernel, so just return 0 */ These two are inconsistent in that the first does load_flag before inc(nhit) while the second does it after. I don't think it matters, but I noticed the inconsistent style and had to tell. Anyway, patch looks reasonable now. Rest is up to Steve, this is his code.
