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-rw-r--r--arch/s390/Kconfig14
-rw-r--r--arch/s390/kernel/Makefile1
-rw-r--r--arch/s390/kernel/entry.S12
-rw-r--r--arch/s390/kernel/entry64.S12
-rw-r--r--arch/s390/kernel/kprobes.c657
-rw-r--r--arch/s390/kernel/traps.c31
-rw-r--r--arch/s390/kernel/vmlinux.lds.S1
-rw-r--r--arch/s390/mm/fault.c40
-rw-r--r--include/asm-s390/kdebug.h59
-rw-r--r--include/asm-s390/kprobes.h114
10 files changed, 937 insertions, 4 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 2f4f70c4dbb2..76122ce1e6cb 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -487,8 +487,22 @@ source "drivers/net/Kconfig"
487 487
488source "fs/Kconfig" 488source "fs/Kconfig"
489 489
490menu "Instrumentation Support"
491
490source "arch/s390/oprofile/Kconfig" 492source "arch/s390/oprofile/Kconfig"
491 493
494config KPROBES
495 bool "Kprobes (EXPERIMENTAL)"
496 depends on EXPERIMENTAL && MODULES
497 help
498 Kprobes allows you to trap at almost any kernel address and
499 execute a callback function. register_kprobe() establishes
500 a probepoint and specifies the callback. Kprobes is useful
501 for kernel debugging, non-intrusive instrumentation and testing.
502 If in doubt, say "N".
503
504endmenu
505
492source "arch/s390/Kconfig.debug" 506source "arch/s390/Kconfig.debug"
493 507
494source "security/Kconfig" 508source "security/Kconfig"
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
index 9a33ed6ca696..33a5069c0e16 100644
--- a/arch/s390/kernel/Makefile
+++ b/arch/s390/kernel/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_COMPAT) += compat_linux.o compat_signal.o \
24 24
25obj-$(CONFIG_VIRT_TIMER) += vtime.o 25obj-$(CONFIG_VIRT_TIMER) += vtime.o
26obj-$(CONFIG_STACKTRACE) += stacktrace.o 26obj-$(CONFIG_STACKTRACE) += stacktrace.o
27obj-$(CONFIG_KPROBES) += kprobes.o
27 28
28# Kexec part 29# Kexec part
29S390_KEXEC_OBJS := machine_kexec.o crash.o 30S390_KEXEC_OBJS := machine_kexec.o crash.o
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index 5b5799ac8f83..0c712b78a7e8 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -505,6 +505,8 @@ pgm_no_vtime2:
505 mvc __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS 505 mvc __THREAD_per+__PER_address(4,%r1),__LC_PER_ADDRESS
506 mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID 506 mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
507 oi __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP 507 oi __TI_flags+3(%r9),_TIF_SINGLE_STEP # set TIF_SINGLE_STEP
508 tm SP_PSW+1(%r15),0x01 # kernel per event ?
509 bz BASED(kernel_per)
508 l %r3,__LC_PGM_ILC # load program interruption code 510 l %r3,__LC_PGM_ILC # load program interruption code
509 la %r8,0x7f 511 la %r8,0x7f
510 nr %r8,%r3 # clear per-event-bit and ilc 512 nr %r8,%r3 # clear per-event-bit and ilc
@@ -536,6 +538,16 @@ pgm_no_vtime3:
536 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 538 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
537 b BASED(sysc_do_svc) 539 b BASED(sysc_do_svc)
538 540
541#
542# per was called from kernel, must be kprobes
543#
544kernel_per:
545 mvi SP_TRAP+1(%r15),0x28 # set trap indication to pgm check
546 la %r2,SP_PTREGS(%r15) # address of register-save area
547 l %r1,BASED(.Lhandle_per) # load adr. of per handler
548 la %r14,BASED(sysc_leave) # load adr. of system return
549 br %r1 # branch to do_single_step
550
539/* 551/*
540 * IO interrupt handler routine 552 * IO interrupt handler routine
541 */ 553 */
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index 56f5f613b868..8b956d1538f5 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -518,6 +518,8 @@ pgm_no_vtime2:
518#endif 518#endif
519 lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct 519 lg %r9,__LC_THREAD_INFO # load pointer to thread_info struct
520 lg %r1,__TI_task(%r9) 520 lg %r1,__TI_task(%r9)
521 tm SP_PSW+1(%r15),0x01 # kernel per event ?
522 jz kernel_per
521 mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID 523 mvc __THREAD_per+__PER_atmid(2,%r1),__LC_PER_ATMID
522 mvc __THREAD_per+__PER_address(8,%r1),__LC_PER_ADDRESS 524 mvc __THREAD_per+__PER_address(8,%r1),__LC_PER_ADDRESS
523 mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID 525 mvc __THREAD_per+__PER_access_id(1,%r1),__LC_PER_ACCESS_ID
@@ -553,6 +555,16 @@ pgm_no_vtime3:
553 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts 555 stosm __SF_EMPTY(%r15),0x03 # reenable interrupts
554 j sysc_do_svc 556 j sysc_do_svc
555 557
558#
559# per was called from kernel, must be kprobes
560#
561kernel_per:
562 lhi %r0,__LC_PGM_OLD_PSW
563 sth %r0,SP_TRAP(%r15) # set trap indication to pgm check
564 la %r2,SP_PTREGS(%r15) # address of register-save area
565 larl %r14,sysc_leave # load adr. of system ret, no work
566 jg do_single_step # branch to do_single_step
567
556/* 568/*
557 * IO interrupt handler routine 569 * IO interrupt handler routine
558 */ 570 */
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
new file mode 100644
index 000000000000..ca28fb0b3790
--- /dev/null
+++ b/arch/s390/kernel/kprobes.c
@@ -0,0 +1,657 @@
1/*
2 * Kernel Probes (KProbes)
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
17 *
18 * Copyright (C) IBM Corporation, 2002, 2006
19 *
20 * s390 port, used ppc64 as template. Mike Grundy <grundym@us.ibm.com>
21 */
22
23#include <linux/config.h>
24#include <linux/kprobes.h>
25#include <linux/ptrace.h>
26#include <linux/preempt.h>
27#include <linux/stop_machine.h>
28#include <asm/cacheflush.h>
29#include <asm/kdebug.h>
30#include <asm/sections.h>
31#include <asm/uaccess.h>
32#include <linux/module.h>
33
34DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
35DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
36
37int __kprobes arch_prepare_kprobe(struct kprobe *p)
38{
39 /* Make sure the probe isn't going on a difficult instruction */
40 if (is_prohibited_opcode((kprobe_opcode_t *) p->addr))
41 return -EINVAL;
42
43 if ((unsigned long)p->addr & 0x01) {
44 printk("Attempt to register kprobe at an unaligned address\n");
45 return -EINVAL;
46 }
47
48 /* Use the get_insn_slot() facility for correctness */
49 if (!(p->ainsn.insn = get_insn_slot()))
50 return -ENOMEM;
51
52 memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
53
54 get_instruction_type(&p->ainsn);
55 p->opcode = *p->addr;
56 return 0;
57}
58
59int __kprobes is_prohibited_opcode(kprobe_opcode_t *instruction)
60{
61 switch (*(__u8 *) instruction) {
62 case 0x0c: /* bassm */
63 case 0x0b: /* bsm */
64 case 0x83: /* diag */
65 case 0x44: /* ex */
66 return -EINVAL;
67 }
68 switch (*(__u16 *) instruction) {
69 case 0x0101: /* pr */
70 case 0xb25a: /* bsa */
71 case 0xb240: /* bakr */
72 case 0xb258: /* bsg */
73 case 0xb218: /* pc */
74 case 0xb228: /* pt */
75 return -EINVAL;
76 }
77 return 0;
78}
79
80void __kprobes get_instruction_type(struct arch_specific_insn *ainsn)
81{
82 /* default fixup method */
83 ainsn->fixup = FIXUP_PSW_NORMAL;
84
85 /* save r1 operand */
86 ainsn->reg = (*ainsn->insn & 0xf0) >> 4;
87
88 /* save the instruction length (pop 5-5) in bytes */
89 switch (*(__u8 *) (ainsn->insn) >> 4) {
90 case 0:
91 ainsn->ilen = 2;
92 break;
93 case 1:
94 case 2:
95 ainsn->ilen = 4;
96 break;
97 case 3:
98 ainsn->ilen = 6;
99 break;
100 }
101
102 switch (*(__u8 *) ainsn->insn) {
103 case 0x05: /* balr */
104 case 0x0d: /* basr */
105 ainsn->fixup = FIXUP_RETURN_REGISTER;
106 /* if r2 = 0, no branch will be taken */
107 if ((*ainsn->insn & 0x0f) == 0)
108 ainsn->fixup |= FIXUP_BRANCH_NOT_TAKEN;
109 break;
110 case 0x06: /* bctr */
111 case 0x07: /* bcr */
112 ainsn->fixup = FIXUP_BRANCH_NOT_TAKEN;
113 break;
114 case 0x45: /* bal */
115 case 0x4d: /* bas */
116 ainsn->fixup = FIXUP_RETURN_REGISTER;
117 break;
118 case 0x47: /* bc */
119 case 0x46: /* bct */
120 case 0x86: /* bxh */
121 case 0x87: /* bxle */
122 ainsn->fixup = FIXUP_BRANCH_NOT_TAKEN;
123 break;
124 case 0x82: /* lpsw */
125 ainsn->fixup = FIXUP_NOT_REQUIRED;
126 break;
127 case 0xb2: /* lpswe */
128 if (*(((__u8 *) ainsn->insn) + 1) == 0xb2) {
129 ainsn->fixup = FIXUP_NOT_REQUIRED;
130 }
131 break;
132 case 0xa7: /* bras */
133 if ((*ainsn->insn & 0x0f) == 0x05) {
134 ainsn->fixup |= FIXUP_RETURN_REGISTER;
135 }
136 break;
137 case 0xc0:
138 if ((*ainsn->insn & 0x0f) == 0x00 /* larl */
139 || (*ainsn->insn & 0x0f) == 0x05) /* brasl */
140 ainsn->fixup |= FIXUP_RETURN_REGISTER;
141 break;
142 case 0xeb:
143 if (*(((__u8 *) ainsn->insn) + 5 ) == 0x44 || /* bxhg */
144 *(((__u8 *) ainsn->insn) + 5) == 0x45) {/* bxleg */
145 ainsn->fixup = FIXUP_BRANCH_NOT_TAKEN;
146 }
147 break;
148 case 0xe3: /* bctg */
149 if (*(((__u8 *) ainsn->insn) + 5) == 0x46) {
150 ainsn->fixup = FIXUP_BRANCH_NOT_TAKEN;
151 }
152 break;
153 }
154}
155
156static int __kprobes swap_instruction(void *aref)
157{
158 struct ins_replace_args *args = aref;
159 int err = -EFAULT;
160
161 asm volatile(
162 "0: mvc 0(2,%2),0(%3)\n"
163 "1: la %0,0\n"
164 "2:\n"
165 EX_TABLE(0b,2b)
166 : "+d" (err), "=m" (*args->ptr)
167 : "a" (args->ptr), "a" (&args->new), "m" (args->new));
168 return err;
169}
170
171void __kprobes arch_arm_kprobe(struct kprobe *p)
172{
173 struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
174 unsigned long status = kcb->kprobe_status;
175 struct ins_replace_args args;
176
177 args.ptr = p->addr;
178 args.old = p->opcode;
179 args.new = BREAKPOINT_INSTRUCTION;
180
181 kcb->kprobe_status = KPROBE_SWAP_INST;
182 stop_machine_run(swap_instruction, &args, NR_CPUS);
183 kcb->kprobe_status = status;
184}
185
186void __kprobes arch_disarm_kprobe(struct kprobe *p)
187{
188 struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
189 unsigned long status = kcb->kprobe_status;
190 struct ins_replace_args args;
191
192 args.ptr = p->addr;
193 args.old = BREAKPOINT_INSTRUCTION;
194 args.new = p->opcode;
195
196 kcb->kprobe_status = KPROBE_SWAP_INST;
197 stop_machine_run(swap_instruction, &args, NR_CPUS);
198 kcb->kprobe_status = status;
199}
200
201void __kprobes arch_remove_kprobe(struct kprobe *p)
202{
203 mutex_lock(&kprobe_mutex);
204 free_insn_slot(p->ainsn.insn);
205 mutex_unlock(&kprobe_mutex);
206}
207
208static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
209{
210 per_cr_bits kprobe_per_regs[1];
211
212 memset(kprobe_per_regs, 0, sizeof(per_cr_bits));
213 regs->psw.addr = (unsigned long)p->ainsn.insn | PSW_ADDR_AMODE;
214
215 /* Set up the per control reg info, will pass to lctl */
216 kprobe_per_regs[0].em_instruction_fetch = 1;
217 kprobe_per_regs[0].starting_addr = (unsigned long)p->ainsn.insn;
218 kprobe_per_regs[0].ending_addr = (unsigned long)p->ainsn.insn + 1;
219
220 /* Set the PER control regs, turns on single step for this address */
221 __ctl_load(kprobe_per_regs, 9, 11);
222 regs->psw.mask |= PSW_MASK_PER;
223 regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK);
224}
225
226static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
227{
228 kcb->prev_kprobe.kp = kprobe_running();
229 kcb->prev_kprobe.status = kcb->kprobe_status;
230 kcb->prev_kprobe.kprobe_saved_imask = kcb->kprobe_saved_imask;
231 memcpy(kcb->prev_kprobe.kprobe_saved_ctl, kcb->kprobe_saved_ctl,
232 sizeof(kcb->kprobe_saved_ctl));
233}
234
235static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
236{
237 __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
238 kcb->kprobe_status = kcb->prev_kprobe.status;
239 kcb->kprobe_saved_imask = kcb->prev_kprobe.kprobe_saved_imask;
240 memcpy(kcb->kprobe_saved_ctl, kcb->prev_kprobe.kprobe_saved_ctl,
241 sizeof(kcb->kprobe_saved_ctl));
242}
243
244static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
245 struct kprobe_ctlblk *kcb)
246{
247 __get_cpu_var(current_kprobe) = p;
248 /* Save the interrupt and per flags */
249 kcb->kprobe_saved_imask = regs->psw.mask &
250 (PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK);
251 /* Save the control regs that govern PER */
252 __ctl_store(kcb->kprobe_saved_ctl, 9, 11);
253}
254
255/* Called with kretprobe_lock held */
256void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
257 struct pt_regs *regs)
258{
259 struct kretprobe_instance *ri;
260
261 if ((ri = get_free_rp_inst(rp)) != NULL) {
262 ri->rp = rp;
263 ri->task = current;
264 ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14];
265
266 /* Replace the return addr with trampoline addr */
267 regs->gprs[14] = (unsigned long)&kretprobe_trampoline;
268
269 add_rp_inst(ri);
270 } else {
271 rp->nmissed++;
272 }
273}
274
275static int __kprobes kprobe_handler(struct pt_regs *regs)
276{
277 struct kprobe *p;
278 int ret = 0;
279 unsigned long *addr = (unsigned long *)
280 ((regs->psw.addr & PSW_ADDR_INSN) - 2);
281 struct kprobe_ctlblk *kcb;
282
283 /*
284 * We don't want to be preempted for the entire
285 * duration of kprobe processing
286 */
287 preempt_disable();
288 kcb = get_kprobe_ctlblk();
289
290 /* Check we're not actually recursing */
291 if (kprobe_running()) {
292 p = get_kprobe(addr);
293 if (p) {
294 if (kcb->kprobe_status == KPROBE_HIT_SS &&
295 *p->ainsn.insn == BREAKPOINT_INSTRUCTION) {
296 regs->psw.mask &= ~PSW_MASK_PER;
297 regs->psw.mask |= kcb->kprobe_saved_imask;
298 goto no_kprobe;
299 }
300 /* We have reentered the kprobe_handler(), since
301 * another probe was hit while within the handler.
302 * We here save the original kprobes variables and
303 * just single step on the instruction of the new probe
304 * without calling any user handlers.
305 */
306 save_previous_kprobe(kcb);
307 set_current_kprobe(p, regs, kcb);
308 kprobes_inc_nmissed_count(p);
309 prepare_singlestep(p, regs);
310 kcb->kprobe_status = KPROBE_REENTER;
311 return 1;
312 } else {
313 p = __get_cpu_var(current_kprobe);
314 if (p->break_handler && p->break_handler(p, regs)) {
315 goto ss_probe;
316 }
317 }
318 goto no_kprobe;
319 }
320
321 p = get_kprobe(addr);
322 if (!p) {
323 if (*addr != BREAKPOINT_INSTRUCTION) {
324 /*
325 * The breakpoint instruction was removed right
326 * after we hit it. Another cpu has removed
327 * either a probepoint or a debugger breakpoint
328 * at this address. In either case, no further
329 * handling of this interrupt is appropriate.
330 *
331 */
332 ret = 1;
333 }
334 /* Not one of ours: let kernel handle it */
335 goto no_kprobe;
336 }
337
338 kcb->kprobe_status = KPROBE_HIT_ACTIVE;
339 set_current_kprobe(p, regs, kcb);
340 if (p->pre_handler && p->pre_handler(p, regs))
341 /* handler has already set things up, so skip ss setup */
342 return 1;
343
344ss_probe:
345 prepare_singlestep(p, regs);
346 kcb->kprobe_status = KPROBE_HIT_SS;
347 return 1;
348
349no_kprobe:
350 preempt_enable_no_resched();
351 return ret;
352}
353
354/*
355 * Function return probe trampoline:
356 * - init_kprobes() establishes a probepoint here
357 * - When the probed function returns, this probe
358 * causes the handlers to fire
359 */
360void __kprobes kretprobe_trampoline_holder(void)
361{
362 asm volatile(".global kretprobe_trampoline\n"
363 "kretprobe_trampoline: bcr 0,0\n");
364}
365
366/*
367 * Called when the probe at kretprobe trampoline is hit
368 */
369int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
370{
371 struct kretprobe_instance *ri = NULL;
372 struct hlist_head *head;
373 struct hlist_node *node, *tmp;
374 unsigned long flags, orig_ret_address = 0;
375 unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
376
377 spin_lock_irqsave(&kretprobe_lock, flags);
378 head = kretprobe_inst_table_head(current);
379
380 /*
381 * It is possible to have multiple instances associated with a given
382 * task either because an multiple functions in the call path
383 * have a return probe installed on them, and/or more then one return
384 * return probe was registered for a target function.
385 *
386 * We can handle this because:
387 * - instances are always inserted at the head of the list
388 * - when multiple return probes are registered for the same
389 * function, the first instance's ret_addr will point to the
390 * real return address, and all the rest will point to
391 * kretprobe_trampoline
392 */
393 hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
394 if (ri->task != current)
395 /* another task is sharing our hash bucket */
396 continue;
397
398 if (ri->rp && ri->rp->handler)
399 ri->rp->handler(ri, regs);
400
401 orig_ret_address = (unsigned long)ri->ret_addr;
402 recycle_rp_inst(ri);
403
404 if (orig_ret_address != trampoline_address) {
405 /*
406 * This is the real return address. Any other
407 * instances associated with this task are for
408 * other calls deeper on the call stack
409 */
410 break;
411 }
412 }
413 BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address));
414 regs->psw.addr = orig_ret_address | PSW_ADDR_AMODE;
415
416 reset_current_kprobe();
417 spin_unlock_irqrestore(&kretprobe_lock, flags);
418 preempt_enable_no_resched();
419
420 /*
421 * By returning a non-zero value, we are telling
422 * kprobe_handler() that we don't want the post_handler
423 * to run (and have re-enabled preemption)
424 */
425 return 1;
426}
427
428/*
429 * Called after single-stepping. p->addr is the address of the
430 * instruction whose first byte has been replaced by the "breakpoint"
431 * instruction. To avoid the SMP problems that can occur when we
432 * temporarily put back the original opcode to single-step, we
433 * single-stepped a copy of the instruction. The address of this
434 * copy is p->ainsn.insn.
435 */
436static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
437{
438 struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
439
440 regs->psw.addr &= PSW_ADDR_INSN;
441
442 if (p->ainsn.fixup & FIXUP_PSW_NORMAL)
443 regs->psw.addr = (unsigned long)p->addr +
444 ((unsigned long)regs->psw.addr -
445 (unsigned long)p->ainsn.insn);
446
447 if (p->ainsn.fixup & FIXUP_BRANCH_NOT_TAKEN)
448 if ((unsigned long)regs->psw.addr -
449 (unsigned long)p->ainsn.insn == p->ainsn.ilen)
450 regs->psw.addr = (unsigned long)p->addr + p->ainsn.ilen;
451
452 if (p->ainsn.fixup & FIXUP_RETURN_REGISTER)
453 regs->gprs[p->ainsn.reg] = ((unsigned long)p->addr +
454 (regs->gprs[p->ainsn.reg] -
455 (unsigned long)p->ainsn.insn))
456 | PSW_ADDR_AMODE;
457
458 regs->psw.addr |= PSW_ADDR_AMODE;
459 /* turn off PER mode */
460 regs->psw.mask &= ~PSW_MASK_PER;
461 /* Restore the original per control regs */
462 __ctl_load(kcb->kprobe_saved_ctl, 9, 11);
463 regs->psw.mask |= kcb->kprobe_saved_imask;
464}
465
466static int __kprobes post_kprobe_handler(struct pt_regs *regs)
467{
468 struct kprobe *cur = kprobe_running();
469 struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
470
471 if (!cur)
472 return 0;
473
474 if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
475 kcb->kprobe_status = KPROBE_HIT_SSDONE;
476 cur->post_handler(cur, regs, 0);
477 }
478
479 resume_execution(cur, regs);
480
481 /*Restore back the original saved kprobes variables and continue. */
482 if (kcb->kprobe_status == KPROBE_REENTER) {
483 restore_previous_kprobe(kcb);
484 goto out;
485 }
486 reset_current_kprobe();
487out:
488 preempt_enable_no_resched();
489
490 /*
491 * if somebody else is singlestepping across a probe point, psw mask
492 * will have PER set, in which case, continue the remaining processing
493 * of do_single_step, as if this is not a probe hit.
494 */
495 if (regs->psw.mask & PSW_MASK_PER) {
496 return 0;
497 }
498
499 return 1;
500}
501
502static int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
503{
504 struct kprobe *cur = kprobe_running();
505 struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
506 const struct exception_table_entry *entry;
507
508 switch(kcb->kprobe_status) {
509 case KPROBE_SWAP_INST:
510 /* We are here because the instruction replacement failed */
511 return 0;
512 case KPROBE_HIT_SS:
513 case KPROBE_REENTER:
514 /*
515 * We are here because the instruction being single
516 * stepped caused a page fault. We reset the current
517 * kprobe and the nip points back to the probe address
518 * and allow the page fault handler to continue as a
519 * normal page fault.
520 */
521 regs->psw.addr = (unsigned long)cur->addr | PSW_ADDR_AMODE;
522 regs->psw.mask &= ~PSW_MASK_PER;
523 regs->psw.mask |= kcb->kprobe_saved_imask;
524 if (kcb->kprobe_status == KPROBE_REENTER)
525 restore_previous_kprobe(kcb);
526 else
527 reset_current_kprobe();
528 preempt_enable_no_resched();
529 break;
530 case KPROBE_HIT_ACTIVE:
531 case KPROBE_HIT_SSDONE:
532 /*
533 * We increment the nmissed count for accounting,
534 * we can also use npre/npostfault count for accouting
535 * these specific fault cases.
536 */
537 kprobes_inc_nmissed_count(cur);
538
539 /*
540 * We come here because instructions in the pre/post
541 * handler caused the page_fault, this could happen
542 * if handler tries to access user space by
543 * copy_from_user(), get_user() etc. Let the
544 * user-specified handler try to fix it first.
545 */
546 if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
547 return 1;
548
549 /*
550 * In case the user-specified fault handler returned
551 * zero, try to fix up.
552 */
553 entry = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
554 if (entry) {
555 regs->psw.addr = entry->fixup | PSW_ADDR_AMODE;
556 return 1;
557 }
558
559 /*
560 * fixup_exception() could not handle it,
561 * Let do_page_fault() fix it.
562 */
563 break;
564 default:
565 break;
566 }
567 return 0;
568}
569
570/*
571 * Wrapper routine to for handling exceptions.
572 */
573int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
574 unsigned long val, void *data)
575{
576 struct die_args *args = (struct die_args *)data;
577 int ret = NOTIFY_DONE;
578
579 switch (val) {
580 case DIE_BPT:
581 if (kprobe_handler(args->regs))
582 ret = NOTIFY_STOP;
583 break;
584 case DIE_SSTEP:
585 if (post_kprobe_handler(args->regs))
586 ret = NOTIFY_STOP;
587 break;
588 case DIE_TRAP:
589 case DIE_PAGE_FAULT:
590 /* kprobe_running() needs smp_processor_id() */
591 preempt_disable();
592 if (kprobe_running() &&
593 kprobe_fault_handler(args->regs, args->trapnr))
594 ret = NOTIFY_STOP;
595 preempt_enable();
596 break;
597 default:
598 break;
599 }
600 return ret;
601}
602
603int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
604{
605 struct jprobe *jp = container_of(p, struct jprobe, kp);
606 unsigned long addr;
607 struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
608
609 memcpy(&kcb->jprobe_saved_regs, regs, sizeof(struct pt_regs));
610
611 /* setup return addr to the jprobe handler routine */
612 regs->psw.addr = (unsigned long)(jp->entry) | PSW_ADDR_AMODE;
613
614 /* r14 is the function return address */
615 kcb->jprobe_saved_r14 = (unsigned long)regs->gprs[14];
616 /* r15 is the stack pointer */
617 kcb->jprobe_saved_r15 = (unsigned long)regs->gprs[15];
618 addr = (unsigned long)kcb->jprobe_saved_r15;
619
620 memcpy(kcb->jprobes_stack, (kprobe_opcode_t *) addr,
621 MIN_STACK_SIZE(addr));
622 return 1;
623}
624
625void __kprobes jprobe_return(void)
626{
627 asm volatile(".word 0x0002");
628}
629
630void __kprobes jprobe_return_end(void)
631{
632 asm volatile("bcr 0,0");
633}
634
635int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
636{
637 struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
638 unsigned long stack_addr = (unsigned long)(kcb->jprobe_saved_r15);
639
640 /* Put the regs back */
641 memcpy(regs, &kcb->jprobe_saved_regs, sizeof(struct pt_regs));
642 /* put the stack back */
643 memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack,
644 MIN_STACK_SIZE(stack_addr));
645 preempt_enable_no_resched();
646 return 1;
647}
648
649static struct kprobe trampoline_p = {
650 .addr = (kprobe_opcode_t *) & kretprobe_trampoline,
651 .pre_handler = trampoline_probe_handler
652};
653
654int __init arch_init_kprobes(void)
655{
656 return register_kprobe(&trampoline_p);
657}
diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c
index bde1d1d59858..c4982c963424 100644
--- a/arch/s390/kernel/traps.c
+++ b/arch/s390/kernel/traps.c
@@ -29,6 +29,7 @@
29#include <linux/module.h> 29#include <linux/module.h>
30#include <linux/kallsyms.h> 30#include <linux/kallsyms.h>
31#include <linux/reboot.h> 31#include <linux/reboot.h>
32#include <linux/kprobes.h>
32 33
33#include <asm/system.h> 34#include <asm/system.h>
34#include <asm/uaccess.h> 35#include <asm/uaccess.h>
@@ -39,6 +40,7 @@
39#include <asm/s390_ext.h> 40#include <asm/s390_ext.h>
40#include <asm/lowcore.h> 41#include <asm/lowcore.h>
41#include <asm/debug.h> 42#include <asm/debug.h>
43#include <asm/kdebug.h>
42 44
43/* Called from entry.S only */ 45/* Called from entry.S only */
44extern void handle_per_exception(struct pt_regs *regs); 46extern void handle_per_exception(struct pt_regs *regs);
@@ -74,6 +76,20 @@ static int kstack_depth_to_print = 12;
74static int kstack_depth_to_print = 20; 76static int kstack_depth_to_print = 20;
75#endif /* CONFIG_64BIT */ 77#endif /* CONFIG_64BIT */
76 78
79ATOMIC_NOTIFIER_HEAD(s390die_chain);
80
81int register_die_notifier(struct notifier_block *nb)
82{
83 return atomic_notifier_chain_register(&s390die_chain, nb);
84}
85EXPORT_SYMBOL(register_die_notifier);
86
87int unregister_die_notifier(struct notifier_block *nb)
88{
89 return atomic_notifier_chain_unregister(&s390die_chain, nb);
90}
91EXPORT_SYMBOL(unregister_die_notifier);
92
77/* 93/*
78 * For show_trace we have tree different stack to consider: 94 * For show_trace we have tree different stack to consider:
79 * - the panic stack which is used if the kernel stack has overflown 95 * - the panic stack which is used if the kernel stack has overflown
@@ -305,8 +321,9 @@ report_user_fault(long interruption_code, struct pt_regs *regs)
305#endif 321#endif
306} 322}
307 323
308static void inline do_trap(long interruption_code, int signr, char *str, 324static void __kprobes inline do_trap(long interruption_code, int signr,
309 struct pt_regs *regs, siginfo_t *info) 325 char *str, struct pt_regs *regs,
326 siginfo_t *info)
310{ 327{
311 /* 328 /*
312 * We got all needed information from the lowcore and can 329 * We got all needed information from the lowcore and can
@@ -315,6 +332,10 @@ static void inline do_trap(long interruption_code, int signr, char *str,
315 if (regs->psw.mask & PSW_MASK_PSTATE) 332 if (regs->psw.mask & PSW_MASK_PSTATE)
316 local_irq_enable(); 333 local_irq_enable();
317 334
335 if (notify_die(DIE_TRAP, str, regs, interruption_code,
336 interruption_code, signr) == NOTIFY_STOP)
337 return;
338
318 if (regs->psw.mask & PSW_MASK_PSTATE) { 339 if (regs->psw.mask & PSW_MASK_PSTATE) {
319 struct task_struct *tsk = current; 340 struct task_struct *tsk = current;
320 341
@@ -336,8 +357,12 @@ static inline void __user *get_check_address(struct pt_regs *regs)
336 return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN); 357 return (void __user *)((regs->psw.addr-S390_lowcore.pgm_ilc) & PSW_ADDR_INSN);
337} 358}
338 359
339void do_single_step(struct pt_regs *regs) 360void __kprobes do_single_step(struct pt_regs *regs)
340{ 361{
362 if (notify_die(DIE_SSTEP, "sstep", regs, 0, 0,
363 SIGTRAP) == NOTIFY_STOP){
364 return;
365 }
341 if ((current->ptrace & PT_PTRACED) != 0) 366 if ((current->ptrace & PT_PTRACED) != 0)
342 force_sig(SIGTRAP, current); 367 force_sig(SIGTRAP, current);
343} 368}
diff --git a/arch/s390/kernel/vmlinux.lds.S b/arch/s390/kernel/vmlinux.lds.S
index ff5f7bb34f75..df0c16ab8e92 100644
--- a/arch/s390/kernel/vmlinux.lds.S
+++ b/arch/s390/kernel/vmlinux.lds.S
@@ -24,6 +24,7 @@ SECTIONS
24 *(.text) 24 *(.text)
25 SCHED_TEXT 25 SCHED_TEXT
26 LOCK_TEXT 26 LOCK_TEXT
27 KPROBES_TEXT
27 *(.fixup) 28 *(.fixup)
28 *(.gnu.warning) 29 *(.gnu.warning)
29 } = 0x0700 30 } = 0x0700
diff --git a/arch/s390/mm/fault.c b/arch/s390/mm/fault.c
index 7cd82575813d..44f0cda7e72e 100644
--- a/arch/s390/mm/fault.c
+++ b/arch/s390/mm/fault.c
@@ -25,10 +25,12 @@
25#include <linux/console.h> 25#include <linux/console.h>
26#include <linux/module.h> 26#include <linux/module.h>
27#include <linux/hardirq.h> 27#include <linux/hardirq.h>
28#include <linux/kprobes.h>
28 29
29#include <asm/system.h> 30#include <asm/system.h>
30#include <asm/uaccess.h> 31#include <asm/uaccess.h>
31#include <asm/pgtable.h> 32#include <asm/pgtable.h>
33#include <asm/kdebug.h>
32 34
33#ifndef CONFIG_64BIT 35#ifndef CONFIG_64BIT
34#define __FAIL_ADDR_MASK 0x7ffff000 36#define __FAIL_ADDR_MASK 0x7ffff000
@@ -48,6 +50,38 @@ extern int sysctl_userprocess_debug;
48 50
49extern void die(const char *,struct pt_regs *,long); 51extern void die(const char *,struct pt_regs *,long);
50 52
53#ifdef CONFIG_KPROBES
54ATOMIC_NOTIFIER_HEAD(notify_page_fault_chain);
55int register_page_fault_notifier(struct notifier_block *nb)
56{
57 return atomic_notifier_chain_register(&notify_page_fault_chain, nb);
58}
59
60int unregister_page_fault_notifier(struct notifier_block *nb)
61{
62 return atomic_notifier_chain_unregister(&notify_page_fault_chain, nb);
63}
64
65static inline int notify_page_fault(enum die_val val, const char *str,
66 struct pt_regs *regs, long err, int trap, int sig)
67{
68 struct die_args args = {
69 .regs = regs,
70 .str = str,
71 .err = err,
72 .trapnr = trap,
73 .signr = sig
74 };
75 return atomic_notifier_call_chain(&notify_page_fault_chain, val, &args);
76}
77#else
78static inline int notify_page_fault(enum die_val val, const char *str,
79 struct pt_regs *regs, long err, int trap, int sig)
80{
81 return NOTIFY_DONE;
82}
83#endif
84
51extern spinlock_t timerlist_lock; 85extern spinlock_t timerlist_lock;
52 86
53/* 87/*
@@ -159,7 +193,7 @@ static void do_sigsegv(struct pt_regs *regs, unsigned long error_code,
159 * 11 Page translation -> Not present (nullification) 193 * 11 Page translation -> Not present (nullification)
160 * 3b Region third trans. -> Not present (nullification) 194 * 3b Region third trans. -> Not present (nullification)
161 */ 195 */
162static inline void 196static inline void __kprobes
163do_exception(struct pt_regs *regs, unsigned long error_code, int is_protection) 197do_exception(struct pt_regs *regs, unsigned long error_code, int is_protection)
164{ 198{
165 struct task_struct *tsk; 199 struct task_struct *tsk;
@@ -173,6 +207,10 @@ do_exception(struct pt_regs *regs, unsigned long error_code, int is_protection)
173 tsk = current; 207 tsk = current;
174 mm = tsk->mm; 208 mm = tsk->mm;
175 209
210 if (notify_page_fault(DIE_PAGE_FAULT, "page fault", regs, error_code, 14,
211 SIGSEGV) == NOTIFY_STOP)
212 return;
213
176 /* 214 /*
177 * Check for low-address protection. This needs to be treated 215 * Check for low-address protection. This needs to be treated
178 * as a special case because the translation exception code 216 * as a special case because the translation exception code
diff --git a/include/asm-s390/kdebug.h b/include/asm-s390/kdebug.h
new file mode 100644
index 000000000000..40cc68025e01
--- /dev/null
+++ b/include/asm-s390/kdebug.h
@@ -0,0 +1,59 @@
1#ifndef _S390_KDEBUG_H
2#define _S390_KDEBUG_H
3
4/*
5 * Feb 2006 Ported to s390 <grundym@us.ibm.com>
6 */
7#include <linux/notifier.h>
8
9struct pt_regs;
10
11struct die_args {
12 struct pt_regs *regs;
13 const char *str;
14 long err;
15 int trapnr;
16 int signr;
17};
18
19/* Note - you should never unregister because that can race with NMIs.
20 * If you really want to do it first unregister - then synchronize_sched
21 * - then free.
22 */
23extern int register_die_notifier(struct notifier_block *);
24extern int unregister_die_notifier(struct notifier_block *);
25extern int register_page_fault_notifier(struct notifier_block *);
26extern int unregister_page_fault_notifier(struct notifier_block *);
27extern struct atomic_notifier_head s390die_chain;
28
29
30enum die_val {
31 DIE_OOPS = 1,
32 DIE_BPT,
33 DIE_SSTEP,
34 DIE_PANIC,
35 DIE_NMI,
36 DIE_DIE,
37 DIE_NMIWATCHDOG,
38 DIE_KERNELDEBUG,
39 DIE_TRAP,
40 DIE_GPF,
41 DIE_CALL,
42 DIE_NMI_IPI,
43 DIE_PAGE_FAULT,
44};
45
46static inline int notify_die(enum die_val val, const char *str,
47 struct pt_regs *regs, long err, int trap, int sig)
48{
49 struct die_args args = {
50 .regs = regs,
51 .str = str,
52 .err = err,
53 .trapnr = trap,
54 .signr = sig
55 };
56 return atomic_notifier_call_chain(&s390die_chain, val, &args);
57}
58
59#endif
diff --git a/include/asm-s390/kprobes.h b/include/asm-s390/kprobes.h
new file mode 100644
index 000000000000..b847ff0ec3fa
--- /dev/null
+++ b/include/asm-s390/kprobes.h
@@ -0,0 +1,114 @@
1#ifndef _ASM_S390_KPROBES_H
2#define _ASM_S390_KPROBES_H
3/*
4 * Kernel Probes (KProbes)
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 *
20 * Copyright (C) IBM Corporation, 2002, 2006
21 *
22 * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
23 * Probes initial implementation ( includes suggestions from
24 * Rusty Russell).
25 * 2004-Nov Modified for PPC64 by Ananth N Mavinakayanahalli
26 * <ananth@in.ibm.com>
27 * 2005-Dec Used as a template for s390 by Mike Grundy
28 * <grundym@us.ibm.com>
29 */
30#include <linux/types.h>
31#include <linux/ptrace.h>
32#include <linux/percpu.h>
33
34#define __ARCH_WANT_KPROBES_INSN_SLOT
35struct pt_regs;
36struct kprobe;
37
38typedef u16 kprobe_opcode_t;
39#define BREAKPOINT_INSTRUCTION 0x0002
40
41/* Maximum instruction size is 3 (16bit) halfwords: */
42#define MAX_INSN_SIZE 0x0003
43#define MAX_STACK_SIZE 64
44#define MIN_STACK_SIZE(ADDR) (((MAX_STACK_SIZE) < \
45 (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR))) \
46 ? (MAX_STACK_SIZE) \
47 : (((unsigned long)current_thread_info()) + THREAD_SIZE - (ADDR)))
48
49#define JPROBE_ENTRY(pentry) (kprobe_opcode_t *)(pentry)
50
51#define ARCH_SUPPORTS_KRETPROBES
52#define ARCH_INACTIVE_KPROBE_COUNT 0
53
54#define KPROBE_SWAP_INST 0x10
55
56#define FIXUP_PSW_NORMAL 0x08
57#define FIXUP_BRANCH_NOT_TAKEN 0x04
58#define FIXUP_RETURN_REGISTER 0x02
59#define FIXUP_NOT_REQUIRED 0x01
60
61/* Architecture specific copy of original instruction */
62struct arch_specific_insn {
63 /* copy of original instruction */
64 kprobe_opcode_t *insn;
65 int fixup;
66 int ilen;
67 int reg;
68};
69
70struct ins_replace_args {
71 kprobe_opcode_t *ptr;
72 kprobe_opcode_t old;
73 kprobe_opcode_t new;
74};
75struct prev_kprobe {
76 struct kprobe *kp;
77 unsigned long status;
78 unsigned long saved_psw;
79 unsigned long kprobe_saved_imask;
80 unsigned long kprobe_saved_ctl[3];
81};
82
83/* per-cpu kprobe control block */
84struct kprobe_ctlblk {
85 unsigned long kprobe_status;
86 unsigned long kprobe_saved_imask;
87 unsigned long kprobe_saved_ctl[3];
88 struct pt_regs jprobe_saved_regs;
89 unsigned long jprobe_saved_r14;
90 unsigned long jprobe_saved_r15;
91 struct prev_kprobe prev_kprobe;
92 kprobe_opcode_t jprobes_stack[MAX_STACK_SIZE];
93};
94
95void arch_remove_kprobe(struct kprobe *p);
96void kretprobe_trampoline(void);
97int is_prohibited_opcode(kprobe_opcode_t *instruction);
98void get_instruction_type(struct arch_specific_insn *ainsn);
99
100#define flush_insn_slot(p) do { } while (0)
101
102#endif /* _ASM_S390_KPROBES_H */
103
104#ifdef CONFIG_KPROBES
105
106extern int kprobe_exceptions_notify(struct notifier_block *self,
107 unsigned long val, void *data);
108#else /* !CONFIG_KPROBES */
109static inline int kprobe_exceptions_notify(struct notifier_block *self,
110 unsigned long val, void *data)
111{
112 return 0;
113}
114#endif
generated by cgit v1.2.2 (git 2.25.0) at 2024-09-21 10:23:29 -0400