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Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -07001/*
2 * Kernel Probes (KProbes)
3 * arch/ia64/kernel/kprobes.c
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 *
19 * Copyright (C) IBM Corporation, 2002, 2004
20 * Copyright (C) Intel Corporation, 2005
21 *
22 * 2005-Apr Rusty Lynch <rusty.lynch@intel.com> and Anil S Keshavamurthy
23 * <anil.s.keshavamurthy@intel.com> adapted from i386
24 */
25
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -070026#include <linux/kprobes.h>
27#include <linux/ptrace.h>
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -070028#include <linux/string.h>
29#include <linux/slab.h>
30#include <linux/preempt.h>
31#include <linux/moduleloader.h>
Christoph Hellwig1eeb66a2007-05-08 00:27:03 -070032#include <linux/kdebug.h>
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -070033
34#include <asm/pgtable.h>
Keshavamurthy Anil Sc7b645f2005-06-27 15:17:16 -070035#include <asm/sections.h>
Prasanna S Panchamukhic04c1c82006-03-26 01:38:25 -080036#include <asm/uaccess.h>
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -070037
Anil S Keshavamurthyb2761dc2005-06-23 00:09:28 -070038extern void jprobe_inst_return(void);
39
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -080040DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
41DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -070042
Masami Hiramatsuf438d912007-10-16 01:27:49 -070043struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}};
44
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -070045enum instruction_type {A, I, M, F, B, L, X, u};
46static enum instruction_type bundle_encoding[32][3] = {
47 { M, I, I }, /* 00 */
48 { M, I, I }, /* 01 */
49 { M, I, I }, /* 02 */
50 { M, I, I }, /* 03 */
51 { M, L, X }, /* 04 */
52 { M, L, X }, /* 05 */
53 { u, u, u }, /* 06 */
54 { u, u, u }, /* 07 */
55 { M, M, I }, /* 08 */
56 { M, M, I }, /* 09 */
57 { M, M, I }, /* 0A */
58 { M, M, I }, /* 0B */
59 { M, F, I }, /* 0C */
60 { M, F, I }, /* 0D */
61 { M, M, F }, /* 0E */
62 { M, M, F }, /* 0F */
63 { M, I, B }, /* 10 */
64 { M, I, B }, /* 11 */
65 { M, B, B }, /* 12 */
66 { M, B, B }, /* 13 */
67 { u, u, u }, /* 14 */
68 { u, u, u }, /* 15 */
69 { B, B, B }, /* 16 */
70 { B, B, B }, /* 17 */
71 { M, M, B }, /* 18 */
72 { M, M, B }, /* 19 */
73 { u, u, u }, /* 1A */
74 { u, u, u }, /* 1B */
75 { M, F, B }, /* 1C */
76 { M, F, B }, /* 1D */
77 { u, u, u }, /* 1E */
78 { u, u, u }, /* 1F */
79};
80
Masami Hiramatsu34e1ceb2008-03-28 14:27:02 -070081/* Insert a long branch code */
82static void __kprobes set_brl_inst(void *from, void *to)
83{
84 s64 rel = ((s64) to - (s64) from) >> 4;
85 bundle_t *brl;
86 brl = (bundle_t *) ((u64) from & ~0xf);
87 brl->quad0.template = 0x05; /* [MLX](stop) */
88 brl->quad0.slot0 = NOP_M_INST; /* nop.m 0x0 */
89 brl->quad0.slot1_p0 = ((rel >> 20) & 0x7fffffffff) << 2;
90 brl->quad1.slot1_p1 = (((rel >> 20) & 0x7fffffffff) << 2) >> (64 - 46);
91 /* brl.cond.sptk.many.clr rel<<4 (qp=0) */
92 brl->quad1.slot2 = BRL_INST(rel >> 59, rel & 0xfffff);
93}
94
Anil S Keshavamurthya5403182005-06-23 00:09:32 -070095/*
96 * In this function we check to see if the instruction
97 * is IP relative instruction and update the kprobe
98 * inst flag accordingly
99 */
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700100static void __kprobes update_kprobe_inst_flag(uint template, uint slot,
101 uint major_opcode,
102 unsigned long kprobe_inst,
103 struct kprobe *p)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700104{
Rusty Lynch8bc76772005-06-23 00:09:30 -0700105 p->ainsn.inst_flag = 0;
106 p->ainsn.target_br_reg = 0;
Tony Luck08ed38b2006-11-14 09:33:38 -0800107 p->ainsn.slot = slot;
Rusty Lynch8bc76772005-06-23 00:09:30 -0700108
Keshavamurthy Anil Sdeac66a2005-09-06 15:19:35 -0700109 /* Check for Break instruction
bibo,mao62c27be2006-10-02 02:17:33 -0700110 * Bits 37:40 Major opcode to be zero
Keshavamurthy Anil Sdeac66a2005-09-06 15:19:35 -0700111 * Bits 27:32 X6 to be zero
112 * Bits 32:35 X3 to be zero
113 */
114 if ((!major_opcode) && (!((kprobe_inst >> 27) & 0x1FF)) ) {
115 /* is a break instruction */
116 p->ainsn.inst_flag |= INST_FLAG_BREAK_INST;
117 return;
118 }
119
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700120 if (bundle_encoding[template][slot] == B) {
121 switch (major_opcode) {
122 case INDIRECT_CALL_OPCODE:
123 p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
bibo,mao62c27be2006-10-02 02:17:33 -0700124 p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
125 break;
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700126 case IP_RELATIVE_PREDICT_OPCODE:
127 case IP_RELATIVE_BRANCH_OPCODE:
128 p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
bibo,mao62c27be2006-10-02 02:17:33 -0700129 break;
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700130 case IP_RELATIVE_CALL_OPCODE:
bibo,mao62c27be2006-10-02 02:17:33 -0700131 p->ainsn.inst_flag |= INST_FLAG_FIX_RELATIVE_IP_ADDR;
132 p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
133 p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
134 break;
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700135 }
bibo,mao62c27be2006-10-02 02:17:33 -0700136 } else if (bundle_encoding[template][slot] == X) {
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700137 switch (major_opcode) {
138 case LONG_CALL_OPCODE:
139 p->ainsn.inst_flag |= INST_FLAG_FIX_BRANCH_REG;
140 p->ainsn.target_br_reg = ((kprobe_inst >> 6) & 0x7);
141 break;
142 }
143 }
144 return;
145}
Rusty Lynch8bc76772005-06-23 00:09:30 -0700146
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700147/*
Anil S Keshavamurthy1674eaf2005-06-23 00:09:33 -0700148 * In this function we check to see if the instruction
149 * (qp) cmpx.crel.ctype p1,p2=r2,r3
150 * on which we are inserting kprobe is cmp instruction
151 * with ctype as unc.
152 */
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700153static uint __kprobes is_cmp_ctype_unc_inst(uint template, uint slot,
154 uint major_opcode,
155 unsigned long kprobe_inst)
Anil S Keshavamurthy1674eaf2005-06-23 00:09:33 -0700156{
157 cmp_inst_t cmp_inst;
158 uint ctype_unc = 0;
159
160 if (!((bundle_encoding[template][slot] == I) ||
161 (bundle_encoding[template][slot] == M)))
162 goto out;
163
164 if (!((major_opcode == 0xC) || (major_opcode == 0xD) ||
165 (major_opcode == 0xE)))
166 goto out;
167
168 cmp_inst.l = kprobe_inst;
169 if ((cmp_inst.f.x2 == 0) || (cmp_inst.f.x2 == 1)) {
Simon Arlott72fdbdc2007-05-11 14:55:43 -0700170 /* Integer compare - Register Register (A6 type)*/
Anil S Keshavamurthy1674eaf2005-06-23 00:09:33 -0700171 if ((cmp_inst.f.tb == 0) && (cmp_inst.f.ta == 0)
172 &&(cmp_inst.f.c == 1))
173 ctype_unc = 1;
174 } else if ((cmp_inst.f.x2 == 2)||(cmp_inst.f.x2 == 3)) {
Simon Arlott72fdbdc2007-05-11 14:55:43 -0700175 /* Integer compare - Immediate Register (A8 type)*/
Anil S Keshavamurthy1674eaf2005-06-23 00:09:33 -0700176 if ((cmp_inst.f.ta == 0) &&(cmp_inst.f.c == 1))
177 ctype_unc = 1;
178 }
179out:
180 return ctype_unc;
181}
182
183/*
bibo,maodf3e0d12006-12-12 12:04:42 -0800184 * In this function we check to see if the instruction
185 * on which we are inserting kprobe is supported.
186 * Returns qp value if supported
187 * Returns -EINVAL if unsupported
188 */
189static int __kprobes unsupported_inst(uint template, uint slot,
190 uint major_opcode,
191 unsigned long kprobe_inst,
192 unsigned long addr)
193{
194 int qp;
195
196 qp = kprobe_inst & 0x3f;
197 if (is_cmp_ctype_unc_inst(template, slot, major_opcode, kprobe_inst)) {
198 if (slot == 1 && qp) {
Joe Perchesc2eeb322007-11-19 17:47:53 -0800199 printk(KERN_WARNING "Kprobes on cmp unc "
200 "instruction on slot 1 at <0x%lx> "
bibo,maodf3e0d12006-12-12 12:04:42 -0800201 "is not supported\n", addr);
202 return -EINVAL;
203
204 }
205 qp = 0;
206 }
207 else if (bundle_encoding[template][slot] == I) {
208 if (major_opcode == 0) {
209 /*
210 * Check for Integer speculation instruction
211 * - Bit 33-35 to be equal to 0x1
212 */
213 if (((kprobe_inst >> 33) & 0x7) == 1) {
214 printk(KERN_WARNING
215 "Kprobes on speculation inst at <0x%lx> not supported\n",
216 addr);
217 return -EINVAL;
218 }
219 /*
220 * IP relative mov instruction
221 * - Bit 27-35 to be equal to 0x30
222 */
223 if (((kprobe_inst >> 27) & 0x1FF) == 0x30) {
224 printk(KERN_WARNING
225 "Kprobes on \"mov r1=ip\" at <0x%lx> not supported\n",
226 addr);
227 return -EINVAL;
228
229 }
230 }
231 else if ((major_opcode == 5) && !(kprobe_inst & (0xFUl << 33)) &&
232 (kprobe_inst & (0x1UL << 12))) {
233 /* test bit instructions, tbit,tnat,tf
234 * bit 33-36 to be equal to 0
235 * bit 12 to be equal to 1
236 */
237 if (slot == 1 && qp) {
Joe Perchesc2eeb322007-11-19 17:47:53 -0800238 printk(KERN_WARNING "Kprobes on test bit "
239 "instruction on slot at <0x%lx> "
bibo,maodf3e0d12006-12-12 12:04:42 -0800240 "is not supported\n", addr);
241 return -EINVAL;
242 }
243 qp = 0;
244 }
245 }
246 else if (bundle_encoding[template][slot] == B) {
247 if (major_opcode == 7) {
248 /* IP-Relative Predict major code is 7 */
249 printk(KERN_WARNING "Kprobes on IP-Relative"
250 "Predict is not supported\n");
251 return -EINVAL;
252 }
253 else if (major_opcode == 2) {
254 /* Indirect Predict, major code is 2
255 * bit 27-32 to be equal to 10 or 11
256 */
257 int x6=(kprobe_inst >> 27) & 0x3F;
258 if ((x6 == 0x10) || (x6 == 0x11)) {
Joe Perchesc2eeb322007-11-19 17:47:53 -0800259 printk(KERN_WARNING "Kprobes on "
bibo,maodf3e0d12006-12-12 12:04:42 -0800260 "Indirect Predict is not supported\n");
261 return -EINVAL;
262 }
263 }
264 }
265 /* kernel does not use float instruction, here for safety kprobe
266 * will judge whether it is fcmp/flass/float approximation instruction
267 */
268 else if (unlikely(bundle_encoding[template][slot] == F)) {
269 if ((major_opcode == 4 || major_opcode == 5) &&
270 (kprobe_inst & (0x1 << 12))) {
271 /* fcmp/fclass unc instruction */
272 if (slot == 1 && qp) {
273 printk(KERN_WARNING "Kprobes on fcmp/fclass "
274 "instruction on slot at <0x%lx> "
275 "is not supported\n", addr);
276 return -EINVAL;
277
278 }
279 qp = 0;
280 }
281 if ((major_opcode == 0 || major_opcode == 1) &&
282 (kprobe_inst & (0x1UL << 33))) {
283 /* float Approximation instruction */
284 if (slot == 1 && qp) {
285 printk(KERN_WARNING "Kprobes on float Approx "
286 "instr at <0x%lx> is not supported\n",
287 addr);
288 return -EINVAL;
289 }
290 qp = 0;
291 }
292 }
293 return qp;
294}
295
296/*
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700297 * In this function we override the bundle with
298 * the break instruction at the given slot.
299 */
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700300static void __kprobes prepare_break_inst(uint template, uint slot,
301 uint major_opcode,
302 unsigned long kprobe_inst,
bibo,maodf3e0d12006-12-12 12:04:42 -0800303 struct kprobe *p,
304 int qp)
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700305{
306 unsigned long break_inst = BREAK_INST;
bibo mao214ddde2006-09-26 11:20:37 -0700307 bundle_t *bundle = &p->opcode.bundle;
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700308
309 /*
310 * Copy the original kprobe_inst qualifying predicate(qp)
bibo,maodf3e0d12006-12-12 12:04:42 -0800311 * to the break instruction
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700312 */
bibo,maodf3e0d12006-12-12 12:04:42 -0800313 break_inst |= qp;
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700314
315 switch (slot) {
316 case 0:
317 bundle->quad0.slot0 = break_inst;
318 break;
319 case 1:
320 bundle->quad0.slot1_p0 = break_inst;
321 bundle->quad1.slot1_p1 = break_inst >> (64-46);
322 break;
323 case 2:
324 bundle->quad1.slot2 = break_inst;
325 break;
326 }
327
328 /*
329 * Update the instruction flag, so that we can
330 * emulate the instruction properly after we
331 * single step on original instruction
332 */
333 update_kprobe_inst_flag(template, slot, major_opcode, kprobe_inst, p);
334}
335
Prasanna S Panchamukhi3ca269d2006-04-18 22:22:02 -0700336static void __kprobes get_kprobe_inst(bundle_t *bundle, uint slot,
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700337 unsigned long *kprobe_inst, uint *major_opcode)
338{
339 unsigned long kprobe_inst_p0, kprobe_inst_p1;
340 unsigned int template;
341
342 template = bundle->quad0.template;
343
344 switch (slot) {
345 case 0:
bibo,mao62c27be2006-10-02 02:17:33 -0700346 *major_opcode = (bundle->quad0.slot0 >> SLOT0_OPCODE_SHIFT);
347 *kprobe_inst = bundle->quad0.slot0;
348 break;
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700349 case 1:
bibo,mao62c27be2006-10-02 02:17:33 -0700350 *major_opcode = (bundle->quad1.slot1_p1 >> SLOT1_p1_OPCODE_SHIFT);
351 kprobe_inst_p0 = bundle->quad0.slot1_p0;
352 kprobe_inst_p1 = bundle->quad1.slot1_p1;
353 *kprobe_inst = kprobe_inst_p0 | (kprobe_inst_p1 << (64-46));
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700354 break;
355 case 2:
bibo,mao62c27be2006-10-02 02:17:33 -0700356 *major_opcode = (bundle->quad1.slot2 >> SLOT2_OPCODE_SHIFT);
357 *kprobe_inst = bundle->quad1.slot2;
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700358 break;
359 }
360}
361
Keshavamurthy Anil Sc7b645f2005-06-27 15:17:16 -0700362/* Returns non-zero if the addr is in the Interrupt Vector Table */
Prasanna S Panchamukhi3ca269d2006-04-18 22:22:02 -0700363static int __kprobes in_ivt_functions(unsigned long addr)
Keshavamurthy Anil Sc7b645f2005-06-27 15:17:16 -0700364{
365 return (addr >= (unsigned long)__start_ivt_text
366 && addr < (unsigned long)__end_ivt_text);
367}
368
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700369static int __kprobes valid_kprobe_addr(int template, int slot,
370 unsigned long addr)
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700371{
372 if ((slot > 2) || ((bundle_encoding[template][1] == L) && slot > 1)) {
Keshavamurthy Anil Sc7b645f2005-06-27 15:17:16 -0700373 printk(KERN_WARNING "Attempting to insert unaligned kprobe "
374 "at 0x%lx\n", addr);
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700375 return -EINVAL;
376 }
Rusty Lyncha528e212005-06-27 15:17:15 -0700377
bibo,mao62c27be2006-10-02 02:17:33 -0700378 if (in_ivt_functions(addr)) {
379 printk(KERN_WARNING "Kprobes can't be inserted inside "
Keshavamurthy Anil Sc7b645f2005-06-27 15:17:16 -0700380 "IVT functions at 0x%lx\n", addr);
bibo,mao62c27be2006-10-02 02:17:33 -0700381 return -EINVAL;
382 }
Keshavamurthy Anil Sc7b645f2005-06-27 15:17:16 -0700383
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700384 return 0;
385}
Rusty Lynch8bc76772005-06-23 00:09:30 -0700386
Prasanna S Panchamukhi3ca269d2006-04-18 22:22:02 -0700387static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700388{
Anil S Keshavamurthycdc7dbd2007-05-11 09:38:40 -0700389 unsigned int i;
390 i = atomic_add_return(1, &kcb->prev_kprobe_index);
391 kcb->prev_kprobe[i-1].kp = kprobe_running();
392 kcb->prev_kprobe[i-1].status = kcb->kprobe_status;
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700393}
394
Prasanna S Panchamukhi3ca269d2006-04-18 22:22:02 -0700395static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700396{
Anil S Keshavamurthycdc7dbd2007-05-11 09:38:40 -0700397 unsigned int i;
Masami Hiramatsu97075c42008-01-18 11:20:46 -0500398 i = atomic_read(&kcb->prev_kprobe_index);
399 __get_cpu_var(current_kprobe) = kcb->prev_kprobe[i-1].kp;
400 kcb->kprobe_status = kcb->prev_kprobe[i-1].status;
401 atomic_sub(1, &kcb->prev_kprobe_index);
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700402}
403
Prasanna S Panchamukhi3ca269d2006-04-18 22:22:02 -0700404static void __kprobes set_current_kprobe(struct kprobe *p,
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800405 struct kprobe_ctlblk *kcb)
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700406{
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800407 __get_cpu_var(current_kprobe) = p;
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700408}
409
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700410static void kretprobe_trampoline(void)
411{
412}
413
414/*
415 * At this point the target function has been tricked into
416 * returning into our trampoline. Lookup the associated instance
417 * and then:
418 * - call the handler function
419 * - cleanup by marking the instance as unused
420 * - long jump back to the original return address
421 */
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700422int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700423{
424 struct kretprobe_instance *ri = NULL;
bibo,mao99219a32006-10-02 02:17:35 -0700425 struct hlist_head *head, empty_rp;
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700426 struct hlist_node *node, *tmp;
Ananth N Mavinakayanahalli991a51d2005-11-07 01:00:14 -0800427 unsigned long flags, orig_ret_address = 0;
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700428 unsigned long trampoline_address =
429 ((struct fnptr *)kretprobe_trampoline)->ip;
430
bibo,mao99219a32006-10-02 02:17:35 -0700431 INIT_HLIST_HEAD(&empty_rp);
Srinivasa D Sef53d9c2008-07-25 01:46:04 -0700432 kretprobe_hash_lock(current, &head, &flags);
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700433
434 /*
435 * It is possible to have multiple instances associated with a given
436 * task either because an multiple functions in the call path
437 * have a return probe installed on them, and/or more then one return
438 * return probe was registered for a target function.
439 *
440 * We can handle this because:
441 * - instances are always inserted at the head of the list
442 * - when multiple return probes are registered for the same
443 * function, the first instance's ret_addr will point to the
444 * real return address, and all the rest will point to
445 * kretprobe_trampoline
446 */
447 hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
Keith Owens9138d582005-11-07 11:27:13 -0800448 if (ri->task != current)
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700449 /* another task is sharing our hash bucket */
Keith Owens9138d582005-11-07 11:27:13 -0800450 continue;
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700451
Shaohua Li36619992007-11-13 14:55:20 +0800452 orig_ret_address = (unsigned long)ri->ret_addr;
453 if (orig_ret_address != trampoline_address)
454 /*
455 * This is the real return address. Any other
456 * instances associated with this task are for
457 * other calls deeper on the call stack
458 */
459 break;
460 }
461
462 regs->cr_iip = orig_ret_address;
463
464 hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
465 if (ri->task != current)
466 /* another task is sharing our hash bucket */
467 continue;
468
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700469 if (ri->rp && ri->rp->handler)
470 ri->rp->handler(ri, regs);
471
472 orig_ret_address = (unsigned long)ri->ret_addr;
bibo,mao99219a32006-10-02 02:17:35 -0700473 recycle_rp_inst(ri, &empty_rp);
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700474
475 if (orig_ret_address != trampoline_address)
476 /*
477 * This is the real return address. Any other
478 * instances associated with this task are for
479 * other calls deeper on the call stack
480 */
481 break;
482 }
483
Ananth N Mavinakayanahalli0f95b7f2007-05-08 00:28:27 -0700484 kretprobe_assert(ri, orig_ret_address, trampoline_address);
485
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800486 reset_current_kprobe();
Srinivasa D Sef53d9c2008-07-25 01:46:04 -0700487 kretprobe_hash_unlock(current, &flags);
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700488 preempt_enable_no_resched();
489
bibo,mao99219a32006-10-02 02:17:35 -0700490 hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
491 hlist_del(&ri->hlist);
492 kfree(ri);
493 }
Ananth N Mavinakayanahallid217d542005-11-07 01:00:14 -0800494 /*
495 * By returning a non-zero value, we are telling
496 * kprobe_handler() that we don't want the post_handler
497 * to run (and have re-enabled preemption)
498 */
Keith Owens9138d582005-11-07 11:27:13 -0800499 return 1;
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700500}
501
Christoph Hellwig4c4308c2007-05-08 00:34:14 -0700502void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700503 struct pt_regs *regs)
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700504{
Christoph Hellwig4c4308c2007-05-08 00:34:14 -0700505 ri->ret_addr = (kprobe_opcode_t *)regs->b0;
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700506
Christoph Hellwig4c4308c2007-05-08 00:34:14 -0700507 /* Replace the return addr with trampoline addr */
508 regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip;
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700509}
510
Masami Hiramatsu34e1ceb2008-03-28 14:27:02 -0700511/* Check the instruction in the slot is break */
512static int __kprobes __is_ia64_break_inst(bundle_t *bundle, uint slot)
513{
514 unsigned int major_opcode;
515 unsigned int template = bundle->quad0.template;
516 unsigned long kprobe_inst;
517
518 /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
519 if (slot == 1 && bundle_encoding[template][1] == L)
520 slot++;
521
522 /* Get Kprobe probe instruction at given slot*/
523 get_kprobe_inst(bundle, slot, &kprobe_inst, &major_opcode);
524
525 /* For break instruction,
526 * Bits 37:40 Major opcode to be zero
527 * Bits 27:32 X6 to be zero
528 * Bits 32:35 X3 to be zero
529 */
530 if (major_opcode || ((kprobe_inst >> 27) & 0x1FF)) {
531 /* Not a break instruction */
532 return 0;
533 }
534
535 /* Is a break instruction */
536 return 1;
537}
538
539/*
540 * In this function, we check whether the target bundle modifies IP or
541 * it triggers an exception. If so, it cannot be boostable.
542 */
543static int __kprobes can_boost(bundle_t *bundle, uint slot,
544 unsigned long bundle_addr)
545{
546 unsigned int template = bundle->quad0.template;
547
548 do {
549 if (search_exception_tables(bundle_addr + slot) ||
550 __is_ia64_break_inst(bundle, slot))
551 return 0; /* exception may occur in this bundle*/
552 } while ((++slot) < 3);
553 template &= 0x1e;
554 if (template >= 0x10 /* including B unit */ ||
555 template == 0x04 /* including X unit */ ||
556 template == 0x06) /* undefined */
557 return 0;
558
559 return 1;
560}
561
562/* Prepare long jump bundle and disables other boosters if need */
563static void __kprobes prepare_booster(struct kprobe *p)
564{
565 unsigned long addr = (unsigned long)p->addr & ~0xFULL;
566 unsigned int slot = (unsigned long)p->addr & 0xf;
567 struct kprobe *other_kp;
568
569 if (can_boost(&p->ainsn.insn[0].bundle, slot, addr)) {
570 set_brl_inst(&p->ainsn.insn[1].bundle, (bundle_t *)addr + 1);
571 p->ainsn.inst_flag |= INST_FLAG_BOOSTABLE;
572 }
573
574 /* disables boosters in previous slots */
575 for (; addr < (unsigned long)p->addr; addr++) {
576 other_kp = get_kprobe((void *)addr);
577 if (other_kp)
578 other_kp->ainsn.inst_flag &= ~INST_FLAG_BOOSTABLE;
579 }
580}
581
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700582int __kprobes arch_prepare_kprobe(struct kprobe *p)
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700583{
584 unsigned long addr = (unsigned long) p->addr;
585 unsigned long *kprobe_addr = (unsigned long *)(addr & ~0xFULL);
586 unsigned long kprobe_inst=0;
587 unsigned int slot = addr & 0xf, template, major_opcode = 0;
bibo mao214ddde2006-09-26 11:20:37 -0700588 bundle_t *bundle;
bibo,maodf3e0d12006-12-12 12:04:42 -0800589 int qp;
Rusty Lynch8bc76772005-06-23 00:09:30 -0700590
bibo mao214ddde2006-09-26 11:20:37 -0700591 bundle = &((kprobe_opcode_t *)kprobe_addr)->bundle;
bibo,mao62c27be2006-10-02 02:17:33 -0700592 template = bundle->quad0.template;
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700593
594 if(valid_kprobe_addr(template, slot, addr))
595 return -EINVAL;
596
597 /* Move to slot 2, if bundle is MLX type and kprobe slot is 1 */
bibo,mao62c27be2006-10-02 02:17:33 -0700598 if (slot == 1 && bundle_encoding[template][1] == L)
599 slot++;
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700600
601 /* Get kprobe_inst and major_opcode from the bundle */
602 get_kprobe_inst(bundle, slot, &kprobe_inst, &major_opcode);
603
bibo,maodf3e0d12006-12-12 12:04:42 -0800604 qp = unsupported_inst(template, slot, major_opcode, kprobe_inst, addr);
605 if (qp < 0)
606 return -EINVAL;
bibo mao214ddde2006-09-26 11:20:37 -0700607
608 p->ainsn.insn = get_insn_slot();
609 if (!p->ainsn.insn)
610 return -ENOMEM;
611 memcpy(&p->opcode, kprobe_addr, sizeof(kprobe_opcode_t));
612 memcpy(p->ainsn.insn, kprobe_addr, sizeof(kprobe_opcode_t));
613
bibo,maodf3e0d12006-12-12 12:04:42 -0800614 prepare_break_inst(template, slot, major_opcode, kprobe_inst, p, qp);
Rusty Lynch8bc76772005-06-23 00:09:30 -0700615
Masami Hiramatsu34e1ceb2008-03-28 14:27:02 -0700616 prepare_booster(p);
617
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700618 return 0;
619}
620
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700621void __kprobes arch_arm_kprobe(struct kprobe *p)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700622{
Tony Luck08ed38b2006-11-14 09:33:38 -0800623 unsigned long arm_addr;
624 bundle_t *src, *dest;
625
626 arm_addr = ((unsigned long)p->addr) & ~0xFUL;
627 dest = &((kprobe_opcode_t *)arm_addr)->bundle;
628 src = &p->opcode.bundle;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700629
bibo mao214ddde2006-09-26 11:20:37 -0700630 flush_icache_range((unsigned long)p->ainsn.insn,
Masami Hiramatsu34e1ceb2008-03-28 14:27:02 -0700631 (unsigned long)p->ainsn.insn +
632 sizeof(kprobe_opcode_t) * MAX_INSN_SIZE);
633
Tony Luck08ed38b2006-11-14 09:33:38 -0800634 switch (p->ainsn.slot) {
635 case 0:
636 dest->quad0.slot0 = src->quad0.slot0;
637 break;
638 case 1:
639 dest->quad1.slot1_p1 = src->quad1.slot1_p1;
640 break;
641 case 2:
642 dest->quad1.slot2 = src->quad1.slot2;
643 break;
644 }
bibo mao214ddde2006-09-26 11:20:37 -0700645 flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t));
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700646}
647
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700648void __kprobes arch_disarm_kprobe(struct kprobe *p)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700649{
Tony Luck08ed38b2006-11-14 09:33:38 -0800650 unsigned long arm_addr;
651 bundle_t *src, *dest;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700652
Tony Luck08ed38b2006-11-14 09:33:38 -0800653 arm_addr = ((unsigned long)p->addr) & ~0xFUL;
654 dest = &((kprobe_opcode_t *)arm_addr)->bundle;
bibo mao214ddde2006-09-26 11:20:37 -0700655 /* p->ainsn.insn contains the original unaltered kprobe_opcode_t */
Tony Luck08ed38b2006-11-14 09:33:38 -0800656 src = &p->ainsn.insn->bundle;
657 switch (p->ainsn.slot) {
658 case 0:
659 dest->quad0.slot0 = src->quad0.slot0;
660 break;
661 case 1:
662 dest->quad1.slot1_p1 = src->quad1.slot1_p1;
663 break;
664 case 2:
665 dest->quad1.slot2 = src->quad1.slot2;
666 break;
667 }
bibo mao214ddde2006-09-26 11:20:37 -0700668 flush_icache_range(arm_addr, arm_addr + sizeof(kprobe_opcode_t));
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700669}
670
bibo mao214ddde2006-09-26 11:20:37 -0700671void __kprobes arch_remove_kprobe(struct kprobe *p)
672{
673 mutex_lock(&kprobe_mutex);
Masami Hiramatsu34e1ceb2008-03-28 14:27:02 -0700674 free_insn_slot(p->ainsn.insn, p->ainsn.inst_flag & INST_FLAG_BOOSTABLE);
bibo mao214ddde2006-09-26 11:20:37 -0700675 mutex_unlock(&kprobe_mutex);
676}
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700677/*
678 * We are resuming execution after a single step fault, so the pt_regs
679 * structure reflects the register state after we executed the instruction
Masami Hiramatsu34e1ceb2008-03-28 14:27:02 -0700680 * located in the kprobe (p->ainsn.insn->bundle). We still need to adjust
Anil S Keshavamurthycd2675b2005-06-23 00:09:29 -0700681 * the ip to point back to the original stack address. To set the IP address
682 * to original stack address, handle the case where we need to fixup the
683 * relative IP address and/or fixup branch register.
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700684 */
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700685static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700686{
bibo,mao62c27be2006-10-02 02:17:33 -0700687 unsigned long bundle_addr = (unsigned long) (&p->ainsn.insn->bundle);
688 unsigned long resume_addr = (unsigned long)p->addr & ~0xFULL;
689 unsigned long template;
690 int slot = ((unsigned long)p->addr & 0xf);
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700691
bibo mao214ddde2006-09-26 11:20:37 -0700692 template = p->ainsn.insn->bundle.quad0.template;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700693
bibo,mao62c27be2006-10-02 02:17:33 -0700694 if (slot == 1 && bundle_encoding[template][1] == L)
695 slot = 2;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700696
Masami Hiramatsu34e1ceb2008-03-28 14:27:02 -0700697 if (p->ainsn.inst_flag & ~INST_FLAG_BOOSTABLE) {
Anil S Keshavamurthycd2675b2005-06-23 00:09:29 -0700698
699 if (p->ainsn.inst_flag & INST_FLAG_FIX_RELATIVE_IP_ADDR) {
700 /* Fix relative IP address */
bibo,mao62c27be2006-10-02 02:17:33 -0700701 regs->cr_iip = (regs->cr_iip - bundle_addr) +
702 resume_addr;
Anil S Keshavamurthycd2675b2005-06-23 00:09:29 -0700703 }
704
705 if (p->ainsn.inst_flag & INST_FLAG_FIX_BRANCH_REG) {
706 /*
707 * Fix target branch register, software convention is
708 * to use either b0 or b6 or b7, so just checking
709 * only those registers
710 */
711 switch (p->ainsn.target_br_reg) {
712 case 0:
713 if ((regs->b0 == bundle_addr) ||
714 (regs->b0 == bundle_addr + 0x10)) {
715 regs->b0 = (regs->b0 - bundle_addr) +
716 resume_addr;
717 }
718 break;
719 case 6:
720 if ((regs->b6 == bundle_addr) ||
721 (regs->b6 == bundle_addr + 0x10)) {
722 regs->b6 = (regs->b6 - bundle_addr) +
723 resume_addr;
724 }
725 break;
726 case 7:
727 if ((regs->b7 == bundle_addr) ||
728 (regs->b7 == bundle_addr + 0x10)) {
729 regs->b7 = (regs->b7 - bundle_addr) +
730 resume_addr;
731 }
732 break;
733 } /* end switch */
734 }
735 goto turn_ss_off;
736 }
737
738 if (slot == 2) {
bibo,mao62c27be2006-10-02 02:17:33 -0700739 if (regs->cr_iip == bundle_addr + 0x10) {
740 regs->cr_iip = resume_addr + 0x10;
741 }
742 } else {
743 if (regs->cr_iip == bundle_addr) {
744 regs->cr_iip = resume_addr;
745 }
Anil S Keshavamurthya5403182005-06-23 00:09:32 -0700746 }
Anil S Keshavamurthycd2675b2005-06-23 00:09:29 -0700747
748turn_ss_off:
bibo,mao62c27be2006-10-02 02:17:33 -0700749 /* Turn off Single Step bit */
750 ia64_psr(regs)->ss = 0;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700751}
752
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700753static void __kprobes prepare_ss(struct kprobe *p, struct pt_regs *regs)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700754{
bibo mao214ddde2006-09-26 11:20:37 -0700755 unsigned long bundle_addr = (unsigned long) &p->ainsn.insn->bundle;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700756 unsigned long slot = (unsigned long)p->addr & 0xf;
757
Keshavamurthy Anil Sdeac66a2005-09-06 15:19:35 -0700758 /* single step inline if break instruction */
759 if (p->ainsn.inst_flag == INST_FLAG_BREAK_INST)
760 regs->cr_iip = (unsigned long)p->addr & ~0xFULL;
761 else
762 regs->cr_iip = bundle_addr & ~0xFULL;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700763
764 if (slot > 2)
765 slot = 0;
766
767 ia64_psr(regs)->ri = slot;
768
769 /* turn on single stepping */
770 ia64_psr(regs)->ss = 1;
771}
772
Keshavamurthy Anil S661e5a32005-09-06 15:19:32 -0700773static int __kprobes is_ia64_break_inst(struct pt_regs *regs)
774{
775 unsigned int slot = ia64_psr(regs)->ri;
Keshavamurthy Anil S661e5a32005-09-06 15:19:32 -0700776 unsigned long *kprobe_addr = (unsigned long *)regs->cr_iip;
777 bundle_t bundle;
778
779 memcpy(&bundle, kprobe_addr, sizeof(bundle_t));
Keshavamurthy Anil S661e5a32005-09-06 15:19:32 -0700780
Masami Hiramatsu34e1ceb2008-03-28 14:27:02 -0700781 return __is_ia64_break_inst(&bundle, slot);
Keshavamurthy Anil S661e5a32005-09-06 15:19:32 -0700782}
783
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700784static int __kprobes pre_kprobes_handler(struct die_args *args)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700785{
786 struct kprobe *p;
787 int ret = 0;
Keshavamurthy Anil S89cb14c2005-06-23 00:09:35 -0700788 struct pt_regs *regs = args->regs;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700789 kprobe_opcode_t *addr = (kprobe_opcode_t *)instruction_pointer(regs);
Ananth N Mavinakayanahallid217d542005-11-07 01:00:14 -0800790 struct kprobe_ctlblk *kcb;
791
792 /*
793 * We don't want to be preempted for the entire
794 * duration of kprobe processing
795 */
796 preempt_disable();
797 kcb = get_kprobe_ctlblk();
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700798
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700799 /* Handle recursion cases */
800 if (kprobe_running()) {
801 p = get_kprobe(addr);
802 if (p) {
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800803 if ((kcb->kprobe_status == KPROBE_HIT_SS) &&
Keshavamurthy Anil Sdeac66a2005-09-06 15:19:35 -0700804 (p->ainsn.inst_flag == INST_FLAG_BREAK_INST)) {
bibo,mao62c27be2006-10-02 02:17:33 -0700805 ia64_psr(regs)->ss = 0;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700806 goto no_kprobe;
807 }
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700808 /* We have reentered the pre_kprobe_handler(), since
809 * another probe was hit while within the handler.
810 * We here save the original kprobes variables and
811 * just single step on the instruction of the new probe
812 * without calling any user handlers.
813 */
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800814 save_previous_kprobe(kcb);
815 set_current_kprobe(p, kcb);
Keshavamurthy Anil Sbf8d5c52005-12-12 00:37:34 -0800816 kprobes_inc_nmissed_count(p);
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700817 prepare_ss(p, regs);
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800818 kcb->kprobe_status = KPROBE_REENTER;
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700819 return 1;
Keshavamurthy Anil S89cb14c2005-06-23 00:09:35 -0700820 } else if (args->err == __IA64_BREAK_JPROBE) {
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700821 /*
822 * jprobe instrumented function just completed
823 */
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800824 p = __get_cpu_var(current_kprobe);
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700825 if (p->break_handler && p->break_handler(p, regs)) {
826 goto ss_probe;
827 }
Keshavamurthy Anil Seb3a7292006-01-11 12:17:42 -0800828 } else if (!is_ia64_break_inst(regs)) {
829 /* The breakpoint instruction was removed by
830 * another cpu right after we hit, no further
831 * handling of this interrupt is appropriate
832 */
833 ret = 1;
834 goto no_kprobe;
Keshavamurthy Anil S89cb14c2005-06-23 00:09:35 -0700835 } else {
836 /* Not our break */
837 goto no_kprobe;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700838 }
839 }
840
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700841 p = get_kprobe(addr);
842 if (!p) {
Keshavamurthy Anil S661e5a32005-09-06 15:19:32 -0700843 if (!is_ia64_break_inst(regs)) {
844 /*
845 * The breakpoint instruction was removed right
846 * after we hit it. Another cpu has removed
847 * either a probepoint or a debugger breakpoint
848 * at this address. In either case, no further
849 * handling of this interrupt is appropriate.
850 */
851 ret = 1;
852
853 }
854
855 /* Not one of our break, let kernel handle it */
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700856 goto no_kprobe;
857 }
858
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800859 set_current_kprobe(p, kcb);
860 kcb->kprobe_status = KPROBE_HIT_ACTIVE;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700861
862 if (p->pre_handler && p->pre_handler(p, regs))
863 /*
864 * Our pre-handler is specifically requesting that we just
Rusty Lynch9508dbf2005-06-27 15:17:12 -0700865 * do a return. This is used for both the jprobe pre-handler
866 * and the kretprobe trampoline
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700867 */
868 return 1;
869
870ss_probe:
Masami Hiramatsu34e1ceb2008-03-28 14:27:02 -0700871#if !defined(CONFIG_PREEMPT) || defined(CONFIG_PM)
872 if (p->ainsn.inst_flag == INST_FLAG_BOOSTABLE && !p->post_handler) {
873 /* Boost up -- we can execute copied instructions directly */
874 ia64_psr(regs)->ri = p->ainsn.slot;
875 regs->cr_iip = (unsigned long)&p->ainsn.insn->bundle & ~0xFULL;
876 /* turn single stepping off */
877 ia64_psr(regs)->ss = 0;
878
879 reset_current_kprobe();
880 preempt_enable_no_resched();
881 return 1;
882 }
883#endif
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700884 prepare_ss(p, regs);
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800885 kcb->kprobe_status = KPROBE_HIT_SS;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700886 return 1;
887
888no_kprobe:
Ananth N Mavinakayanahallid217d542005-11-07 01:00:14 -0800889 preempt_enable_no_resched();
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700890 return ret;
891}
892
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700893static int __kprobes post_kprobes_handler(struct pt_regs *regs)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700894{
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800895 struct kprobe *cur = kprobe_running();
896 struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
897
898 if (!cur)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700899 return 0;
900
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800901 if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
902 kcb->kprobe_status = KPROBE_HIT_SSDONE;
903 cur->post_handler(cur, regs, 0);
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700904 }
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700905
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800906 resume_execution(cur, regs);
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700907
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700908 /*Restore back the original saved kprobes variables and continue. */
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800909 if (kcb->kprobe_status == KPROBE_REENTER) {
910 restore_previous_kprobe(kcb);
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700911 goto out;
912 }
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800913 reset_current_kprobe();
Anil S Keshavamurthy852cacc2005-06-23 00:09:40 -0700914
915out:
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700916 preempt_enable_no_resched();
917 return 1;
918}
919
Harvey Harrison45e18c22008-03-06 09:49:01 -0800920int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700921{
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -0800922 struct kprobe *cur = kprobe_running();
923 struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
924
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700925
Prasanna S Panchamukhic04c1c82006-03-26 01:38:25 -0800926 switch(kcb->kprobe_status) {
927 case KPROBE_HIT_SS:
928 case KPROBE_REENTER:
929 /*
930 * We are here because the instruction being single
931 * stepped caused a page fault. We reset the current
932 * kprobe and the instruction pointer points back to
933 * the probe address and allow the page fault handler
934 * to continue as a normal page fault.
935 */
936 regs->cr_iip = ((unsigned long)cur->addr) & ~0xFULL;
937 ia64_psr(regs)->ri = ((unsigned long)cur->addr) & 0xf;
938 if (kcb->kprobe_status == KPROBE_REENTER)
939 restore_previous_kprobe(kcb);
940 else
941 reset_current_kprobe();
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700942 preempt_enable_no_resched();
Prasanna S Panchamukhic04c1c82006-03-26 01:38:25 -0800943 break;
944 case KPROBE_HIT_ACTIVE:
945 case KPROBE_HIT_SSDONE:
946 /*
947 * We increment the nmissed count for accounting,
948 * we can also use npre/npostfault count for accouting
949 * these specific fault cases.
950 */
951 kprobes_inc_nmissed_count(cur);
952
953 /*
954 * We come here because instructions in the pre/post
955 * handler caused the page_fault, this could happen
956 * if handler tries to access user space by
957 * copy_from_user(), get_user() etc. Let the
958 * user-specified handler try to fix it first.
959 */
960 if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
961 return 1;
Keshavamurthy Anil Sfd32cb32006-09-25 16:32:20 -0700962 /*
963 * In case the user-specified fault handler returned
964 * zero, try to fix up.
965 */
966 if (ia64_done_with_exception(regs))
967 return 1;
Prasanna S Panchamukhic04c1c82006-03-26 01:38:25 -0800968
969 /*
970 * Let ia64_do_page_fault() fix it.
971 */
972 break;
973 default:
974 break;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700975 }
976
977 return 0;
978}
979
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -0700980int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
981 unsigned long val, void *data)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700982{
983 struct die_args *args = (struct die_args *)data;
Ananth N Mavinakayanahalli66ff2d02005-11-07 01:00:07 -0800984 int ret = NOTIFY_DONE;
985
bibo,mao2326c772006-03-26 01:38:21 -0800986 if (args->regs && user_mode(args->regs))
987 return ret;
988
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700989 switch(val) {
990 case DIE_BREAK:
Keith Owens9138d582005-11-07 11:27:13 -0800991 /* err is break number from ia64_bad_break() */
Tony Luck08ed38b2006-11-14 09:33:38 -0800992 if ((args->err >> 12) == (__IA64_BREAK_KPROBE >> 12)
993 || args->err == __IA64_BREAK_JPROBE
994 || args->err == 0)
Keith Owens9138d582005-11-07 11:27:13 -0800995 if (pre_kprobes_handler(args))
996 ret = NOTIFY_STOP;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -0700997 break;
Keith Owens9138d582005-11-07 11:27:13 -0800998 case DIE_FAULT:
999 /* err is vector number from ia64_fault() */
1000 if (args->err == 36)
1001 if (post_kprobes_handler(args->regs))
1002 ret = NOTIFY_STOP;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -07001003 break;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -07001004 default:
1005 break;
1006 }
Ananth N Mavinakayanahalli66ff2d02005-11-07 01:00:07 -08001007 return ret;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -07001008}
1009
Zhang Yanmind3ef1f52006-01-13 14:45:21 -08001010struct param_bsp_cfm {
1011 unsigned long ip;
1012 unsigned long *bsp;
1013 unsigned long cfm;
1014};
1015
1016static void ia64_get_bsp_cfm(struct unw_frame_info *info, void *arg)
1017{
1018 unsigned long ip;
1019 struct param_bsp_cfm *lp = arg;
1020
1021 do {
1022 unw_get_ip(info, &ip);
1023 if (ip == 0)
1024 break;
1025 if (ip == lp->ip) {
1026 unw_get_bsp(info, (unsigned long*)&lp->bsp);
1027 unw_get_cfm(info, (unsigned long*)&lp->cfm);
1028 return;
1029 }
1030 } while (unw_unwind(info) >= 0);
Matthew Wilcoxd61b49c2006-10-26 12:22:32 -06001031 lp->bsp = NULL;
Zhang Yanmind3ef1f52006-01-13 14:45:21 -08001032 lp->cfm = 0;
1033 return;
1034}
1035
Michael Ellerman3d7e3382007-07-19 01:48:11 -07001036unsigned long arch_deref_entry_point(void *entry)
1037{
1038 return ((struct fnptr *)entry)->ip;
1039}
1040
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -07001041int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -07001042{
Anil S Keshavamurthyb2761dc2005-06-23 00:09:28 -07001043 struct jprobe *jp = container_of(p, struct jprobe, kp);
Michael Ellerman3d7e3382007-07-19 01:48:11 -07001044 unsigned long addr = arch_deref_entry_point(jp->entry);
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -08001045 struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
Zhang Yanmind3ef1f52006-01-13 14:45:21 -08001046 struct param_bsp_cfm pa;
1047 int bytes;
1048
1049 /*
1050 * Callee owns the argument space and could overwrite it, eg
1051 * tail call optimization. So to be absolutely safe
Simon Arlott72fdbdc2007-05-11 14:55:43 -07001052 * we save the argument space before transferring the control
Zhang Yanmind3ef1f52006-01-13 14:45:21 -08001053 * to instrumented jprobe function which runs in
1054 * the process context
1055 */
1056 pa.ip = regs->cr_iip;
1057 unw_init_running(ia64_get_bsp_cfm, &pa);
1058 bytes = (char *)ia64_rse_skip_regs(pa.bsp, pa.cfm & 0x3f)
1059 - (char *)pa.bsp;
1060 memcpy( kcb->jprobes_saved_stacked_regs,
1061 pa.bsp,
1062 bytes );
1063 kcb->bsp = pa.bsp;
1064 kcb->cfm = pa.cfm;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -07001065
Anil S Keshavamurthyb2761dc2005-06-23 00:09:28 -07001066 /* save architectural state */
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -08001067 kcb->jprobe_saved_regs = *regs;
Anil S Keshavamurthyb2761dc2005-06-23 00:09:28 -07001068
1069 /* after rfi, execute the jprobe instrumented function */
1070 regs->cr_iip = addr & ~0xFULL;
1071 ia64_psr(regs)->ri = addr & 0xf;
1072 regs->r1 = ((struct fnptr *)(jp->entry))->gp;
1073
1074 /*
1075 * fix the return address to our jprobe_inst_return() function
1076 * in the jprobes.S file
1077 */
bibo,mao62c27be2006-10-02 02:17:33 -07001078 regs->b0 = ((struct fnptr *)(jprobe_inst_return))->ip;
Anil S Keshavamurthyb2761dc2005-06-23 00:09:28 -07001079
1080 return 1;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -07001081}
1082
Adrian Bunk9dad6f52008-03-03 20:07:22 +02001083/* ia64 does not need this */
1084void __kprobes jprobe_return(void)
1085{
1086}
1087
Prasanna S Panchamukhi1f7ad572005-09-06 15:19:30 -07001088int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -07001089{
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -08001090 struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
Zhang Yanmind3ef1f52006-01-13 14:45:21 -08001091 int bytes;
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -08001092
Zhang Yanmind3ef1f52006-01-13 14:45:21 -08001093 /* restoring architectural state */
Ananth N Mavinakayanahalli8a5c4dc2005-11-07 01:00:09 -08001094 *regs = kcb->jprobe_saved_regs;
Zhang Yanmind3ef1f52006-01-13 14:45:21 -08001095
1096 /* restoring the original argument space */
1097 flush_register_stack();
1098 bytes = (char *)ia64_rse_skip_regs(kcb->bsp, kcb->cfm & 0x3f)
1099 - (char *)kcb->bsp;
1100 memcpy( kcb->bsp,
1101 kcb->jprobes_saved_stacked_regs,
1102 bytes );
1103 invalidate_stacked_regs();
1104
Ananth N Mavinakayanahallid217d542005-11-07 01:00:14 -08001105 preempt_enable_no_resched();
Anil S Keshavamurthyb2761dc2005-06-23 00:09:28 -07001106 return 1;
Anil S Keshavamurthyfd7b2312005-06-23 00:09:28 -07001107}
Rusty Lynch9508dbf2005-06-27 15:17:12 -07001108
1109static struct kprobe trampoline_p = {
1110 .pre_handler = trampoline_probe_handler
1111};
1112
Rusty Lynch67729262005-07-05 18:54:50 -07001113int __init arch_init_kprobes(void)
Rusty Lynch9508dbf2005-06-27 15:17:12 -07001114{
1115 trampoline_p.addr =
1116 (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip;
1117 return register_kprobe(&trampoline_p);
1118}
Ananth N Mavinakayanahallibf8f6e5b2007-05-08 00:34:16 -07001119
1120int __kprobes arch_trampoline_kprobe(struct kprobe *p)
1121{
1122 if (p->addr ==
1123 (kprobe_opcode_t *)((struct fnptr *)kretprobe_trampoline)->ip)
1124 return 1;
1125
1126 return 0;
1127}