Re: [for-next][PATCH 14/15] tracepoint: Do not fail unregistering a probe due to memory failure
From: Peter Zijlstra <peterz@infradead.org>
Date: 2021-02-03 17:10:51
Also in:
bpf, lkml
On Wed, Feb 03, 2021 at 11:05:31AM -0500, Steven Rostedt wrote:
+ if (new) {
+ for (i = 0; old[i].func; i++)
+ if ((old[i].func != tp_func->func
+ || old[i].data != tp_func->data)
+ && old[i].func != tp_stub_func)logical operators go at the end..
+ new[j++] = old[i];
+ new[nr_probes - nr_del].func = NULL;
+ *funcs = new;
+ } else {
+ /*
+ * Failed to allocate, replace the old function
+ * with calls to tp_stub_func.
+ */
+ for (i = 0; old[i].func; i++)
{
+ if (old[i].func == tp_func->func &&
+ old[i].data == tp_func->data) {like here.
+ old[i].func = tp_stub_func; + /* Set the prio to the next event. */ + if (old[i + 1].func) + old[i].prio = + old[i + 1].prio;
multi line demands { }, but in this case just don't line-break.
+ else + old[i].prio = -1; + }
}
quoted hunk ↗ jump to hunk
+ *funcs = old; + } } debug_print_probes(*funcs); return old;@@ -295,10 +341,12 @@ static int tracepoint_remove_func(struct tracepoint *tp, tp_funcs = rcu_dereference_protected(tp->funcs, lockdep_is_held(&tracepoints_mutex)); old = func_remove(&tp_funcs, func); - if (IS_ERR(old)) { - WARN_ON_ONCE(PTR_ERR(old) != -ENOMEM); + if (WARN_ON_ONCE(IS_ERR(old))) return PTR_ERR(old); - } + + if (tp_funcs == old) + /* Failed allocating new tp_funcs, replaced func with stub */ + return 0;
{ }