Re: [PATCH V7 04/15] kprobes: Add perf ksymbol events for kprobe insn pages

[Peter Zijlstra]

On Tue, May 12, 2020 at 03:19:11PM +0300, Adrian Hunter wrote:
> @@ -202,6 +207,13 @@ static int collect_one_slot(struct kprobe_insn_page *kip, int idx)
>  		 * next time somebody inserts a probe.
>  		 */
>  		if (!list_is_singular(&kip->list)) {
> +			/*
> +			 * Record perf ksymbol unregister event before removing
> +			 * the page.
> +			 */
> +			perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
> +					   (u64)kip->insns, PAGE_SIZE, true,
> +					   kip->cache->sym);
>  			list_del_rcu(&kip->list);
>  			synchronize_rcu();
>  			kip->cache->free(kip->insns);

My manual build script haz complaints:

i386-defconfig  ../kernel/kprobes.c: In function â__get_insn_slotâ:
../kernel/kprobes.c:190:51: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL, (u64)kip->insns,
^
../kernel/kprobes.c: In function âcollect_one_slotâ:
../kernel/kprobes.c:215:9: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
(u64)kip->insns, PAGE_SIZE, true,
^
FAIL


Now, there's a ton of such warnings elsewhere in the tree, but still I
feel we should perhaps strive for a clean build.