kprobes: Clean up insn_pages by using list instead of hlist (c5cb5a2d) · Commits · 戴 / test

kernel/kprobes.c

+11 −19

Original line number	Diff line number	Diff line
		@@ -103,7 +103,7 @@ static struct kprobe_blackpoint kprobe_blacklist[] = {
		#define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t)))

		struct kprobe_insn_page {
		struct hlist_node hlist;
		struct list_head list;
		kprobe_opcode_t insns; / Page of instruction slots */
		char slot_used[INSNS_PER_PAGE];
		int nused;
		@@ -117,7 +117,7 @@ enum kprobe_slot_state {
		};

		static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */
		static struct hlist_head kprobe_insn_pages;
		static LIST_HEAD(kprobe_insn_pages);
		static int kprobe_garbage_slots;
		static int collect_garbage_slots(void);

		@@ -152,10 +152,9 @@ loop_end:
		static kprobe_opcode_t __kprobes *__get_insn_slot(void)
		{
		struct kprobe_insn_page *kip;
		struct hlist_node *pos;

		retry:
		hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
		list_for_each_entry(kip, &kprobe_insn_pages, list) {
		if (kip->nused < INSNS_PER_PAGE) {
		int i;
		for (i = 0; i < INSNS_PER_PAGE; i++) {
		@@ -189,8 +188,8 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(void)
		kfree(kip);
		return NULL;
		}
		INIT_HLIST_NODE(&kip->hlist);
		hlist_add_head(&kip->hlist, &kprobe_insn_pages);
		INIT_LIST_HEAD(&kip->list);
		list_add(&kip->list, &kprobe_insn_pages);
		memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE);
		kip->slot_used[0] = SLOT_USED;
		kip->nused = 1;
		@@ -219,12 +218,8 @@ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
		* so as not to have to set it up again the
		* next time somebody inserts a probe.
		*/
		hlist_del(&kip->hlist);
		if (hlist_empty(&kprobe_insn_pages)) {
		INIT_HLIST_NODE(&kip->hlist);
		hlist_add_head(&kip->hlist,
		&kprobe_insn_pages);
		} else {
		if (!list_is_singular(&kprobe_insn_pages)) {
		list_del(&kip->list);
		module_free(NULL, kip->insns);
		kfree(kip);
		}
		@@ -235,14 +230,13 @@ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)

		static int __kprobes collect_garbage_slots(void)
		{
		struct kprobe_insn_page *kip;
		struct hlist_node pos, next;
		struct kprobe_insn_page kip, next;

		/* Ensure no-one is preepmted on the garbages */
		if (check_safety())
		return -EAGAIN;

		hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) {
		list_for_each_entry_safe(kip, next, &kprobe_insn_pages, list) {
		int i;
		if (kip->ngarbage == 0)
		continue;
		@@ -260,19 +254,17 @@ static int __kprobes collect_garbage_slots(void)
		void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)
		{
		struct kprobe_insn_page *kip;
		struct hlist_node *pos;

		mutex_lock(&kprobe_insn_mutex);
		hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) {
		list_for_each_entry(kip, &kprobe_insn_pages, list) {
		if (kip->insns <= slot &&
		slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) {
		int i = (slot - kip->insns) / MAX_INSN_SIZE;
		if (dirty) {
		kip->slot_used[i] = SLOT_DIRTY;
		kip->ngarbage++;
		} else {
		} else
		collect_one_slot(kip, i);
		}
		break;
		}
		}

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