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    SubjectRe: [PATCH v2 1/2] kprobes: propagate error from arm_kprobe_ftrace()
    Hi Jessica,

    Since this is under discussion about ftrace part, I just comment another one.

    On Thu, 2 Nov 2017 17:33:33 +0100
    Jessica Yu <jeyu@kernel.org> wrote:

    [...]
    > @@ -1362,9 +1372,14 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p)
    >
    > if (ret == 0 && kprobe_disabled(ap) && !kprobe_disabled(p)) {
    > ap->flags &= ~KPROBE_FLAG_DISABLED;
    > - if (!kprobes_all_disarmed)
    > + if (!kprobes_all_disarmed) {
    > /* Arm the breakpoint again. */
    > - arm_kprobe(ap);
    > + ret = arm_kprobe(ap);
    > + if (ret) {
    > + ap->flags |= KPROBE_FLAG_DISABLED;
    > + list_del_rcu(&p->list);

    You also have to wait rcu here.

    > + }
    > + }
    > }
    > return ret;
    > }
    [...]
    > @@ -2428,16 +2452,26 @@ static void arm_all_kprobes(void)
    > /* Arming kprobes doesn't optimize kprobe itself */
    > for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
    > head = &kprobe_table[i];
    > - hlist_for_each_entry_rcu(p, head, hlist)
    > - if (!kprobe_disabled(p))
    > - arm_kprobe(p);
    > + /* Arm all kprobes on a best-effort basis */
    > + hlist_for_each_entry_rcu(p, head, hlist) {
    > + if (!kprobe_disabled(p)) {
    > + err = arm_kprobe(p);
    > + if (err) {
    > + errors++;
    > + ret = err;
    > + }
    > + }
    > + }
    > }
    >
    > - printk(KERN_INFO "Kprobes globally enabled\n");
    > + if (errors)
    > + pr_warn("Kprobes globally enabled, but failed to arm %d kprobes\n", errors);

    The last "kprobes" should be "probes" because it can include kretprobes :P

    Thank you,

    --
    Masami Hiramatsu <mhiramat@kernel.org>

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