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-rw-r--r--kernel/kprobes.c38
1 files changed, 13 insertions, 25 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index c0fa54b276d9..ef177d653b2c 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -103,7 +103,7 @@ static struct kprobe_blackpoint kprobe_blacklist[] = {
103#define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t))) 103#define INSNS_PER_PAGE (PAGE_SIZE/(MAX_INSN_SIZE * sizeof(kprobe_opcode_t)))
104 104
105struct kprobe_insn_page { 105struct kprobe_insn_page {
106 struct hlist_node hlist; 106 struct list_head list;
107 kprobe_opcode_t *insns; /* Page of instruction slots */ 107 kprobe_opcode_t *insns; /* Page of instruction slots */
108 char slot_used[INSNS_PER_PAGE]; 108 char slot_used[INSNS_PER_PAGE];
109 int nused; 109 int nused;
@@ -117,7 +117,7 @@ enum kprobe_slot_state {
117}; 117};
118 118
119static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */ 119static DEFINE_MUTEX(kprobe_insn_mutex); /* Protects kprobe_insn_pages */
120static struct hlist_head kprobe_insn_pages; 120static LIST_HEAD(kprobe_insn_pages);
121static int kprobe_garbage_slots; 121static int kprobe_garbage_slots;
122static int collect_garbage_slots(void); 122static int collect_garbage_slots(void);
123 123
@@ -152,10 +152,9 @@ loop_end:
152static kprobe_opcode_t __kprobes *__get_insn_slot(void) 152static kprobe_opcode_t __kprobes *__get_insn_slot(void)
153{ 153{
154 struct kprobe_insn_page *kip; 154 struct kprobe_insn_page *kip;
155 struct hlist_node *pos;
156 155
157 retry: 156 retry:
158 hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) { 157 list_for_each_entry(kip, &kprobe_insn_pages, list) {
159 if (kip->nused < INSNS_PER_PAGE) { 158 if (kip->nused < INSNS_PER_PAGE) {
160 int i; 159 int i;
161 for (i = 0; i < INSNS_PER_PAGE; i++) { 160 for (i = 0; i < INSNS_PER_PAGE; i++) {
@@ -189,8 +188,8 @@ static kprobe_opcode_t __kprobes *__get_insn_slot(void)
189 kfree(kip); 188 kfree(kip);
190 return NULL; 189 return NULL;
191 } 190 }
192 INIT_HLIST_NODE(&kip->hlist); 191 INIT_LIST_HEAD(&kip->list);
193 hlist_add_head(&kip->hlist, &kprobe_insn_pages); 192 list_add(&kip->list, &kprobe_insn_pages);
194 memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE); 193 memset(kip->slot_used, SLOT_CLEAN, INSNS_PER_PAGE);
195 kip->slot_used[0] = SLOT_USED; 194 kip->slot_used[0] = SLOT_USED;
196 kip->nused = 1; 195 kip->nused = 1;
@@ -219,12 +218,8 @@ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
219 * so as not to have to set it up again the 218 * so as not to have to set it up again the
220 * next time somebody inserts a probe. 219 * next time somebody inserts a probe.
221 */ 220 */
222 hlist_del(&kip->hlist); 221 if (!list_is_singular(&kprobe_insn_pages)) {
223 if (hlist_empty(&kprobe_insn_pages)) { 222 list_del(&kip->list);
224 INIT_HLIST_NODE(&kip->hlist);
225 hlist_add_head(&kip->hlist,
226 &kprobe_insn_pages);
227 } else {
228 module_free(NULL, kip->insns); 223 module_free(NULL, kip->insns);
229 kfree(kip); 224 kfree(kip);
230 } 225 }
@@ -235,18 +230,13 @@ static int __kprobes collect_one_slot(struct kprobe_insn_page *kip, int idx)
235 230
236static int __kprobes collect_garbage_slots(void) 231static int __kprobes collect_garbage_slots(void)
237{ 232{
238 struct kprobe_insn_page *kip; 233 struct kprobe_insn_page *kip, *next;
239 struct hlist_node *pos, *next;
240 int safety;
241 234
242 /* Ensure no-one is preepmted on the garbages */ 235 /* Ensure no-one is preepmted on the garbages */
243 mutex_unlock(&kprobe_insn_mutex); 236 if (check_safety())
244 safety = check_safety();
245 mutex_lock(&kprobe_insn_mutex);
246 if (safety != 0)
247 return -EAGAIN; 237 return -EAGAIN;
248 238
249 hlist_for_each_entry_safe(kip, pos, next, &kprobe_insn_pages, hlist) { 239 list_for_each_entry_safe(kip, next, &kprobe_insn_pages, list) {
250 int i; 240 int i;
251 if (kip->ngarbage == 0) 241 if (kip->ngarbage == 0)
252 continue; 242 continue;
@@ -264,19 +254,17 @@ static int __kprobes collect_garbage_slots(void)
264void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty) 254void __kprobes free_insn_slot(kprobe_opcode_t * slot, int dirty)
265{ 255{
266 struct kprobe_insn_page *kip; 256 struct kprobe_insn_page *kip;
267 struct hlist_node *pos;
268 257
269 mutex_lock(&kprobe_insn_mutex); 258 mutex_lock(&kprobe_insn_mutex);
270 hlist_for_each_entry(kip, pos, &kprobe_insn_pages, hlist) { 259 list_for_each_entry(kip, &kprobe_insn_pages, list) {
271 if (kip->insns <= slot && 260 if (kip->insns <= slot &&
272 slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) { 261 slot < kip->insns + (INSNS_PER_PAGE * MAX_INSN_SIZE)) {
273 int i = (slot - kip->insns) / MAX_INSN_SIZE; 262 int i = (slot - kip->insns) / MAX_INSN_SIZE;
274 if (dirty) { 263 if (dirty) {
275 kip->slot_used[i] = SLOT_DIRTY; 264 kip->slot_used[i] = SLOT_DIRTY;
276 kip->ngarbage++; 265 kip->ngarbage++;
277 } else { 266 } else
278 collect_one_slot(kip, i); 267 collect_one_slot(kip, i);
279 }
280 break; 268 break;
281 } 269 }
282 } 270 }
@@ -698,7 +686,7 @@ int __kprobes register_kprobe(struct kprobe *p)
698 p->addr = addr; 686 p->addr = addr;
699 687
700 preempt_disable(); 688 preempt_disable();
701 if (!__kernel_text_address((unsigned long) p->addr) || 689 if (!kernel_text_address((unsigned long) p->addr) ||
702 in_kprobes_functions((unsigned long) p->addr)) { 690 in_kprobes_functions((unsigned long) p->addr)) {
703 preempt_enable(); 691 preempt_enable();
704 return -EINVAL; 692 return -EINVAL;