5532bd0f85
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
671 lines
18 KiB
C
671 lines
18 KiB
C
/*
|
|
* Kernel Probes (KProbes)
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*
|
|
* Copyright (C) IBM Corporation, 2002, 2006
|
|
*
|
|
* s390 port, used ppc64 as template. Mike Grundy <grundym@us.ibm.com>
|
|
*/
|
|
|
|
#include <linux/kprobes.h>
|
|
#include <linux/ptrace.h>
|
|
#include <linux/preempt.h>
|
|
#include <linux/stop_machine.h>
|
|
#include <linux/kdebug.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/sections.h>
|
|
#include <asm/uaccess.h>
|
|
#include <linux/module.h>
|
|
|
|
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
|
|
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
|
|
|
|
struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}};
|
|
|
|
int __kprobes arch_prepare_kprobe(struct kprobe *p)
|
|
{
|
|
/* Make sure the probe isn't going on a difficult instruction */
|
|
if (is_prohibited_opcode((kprobe_opcode_t *) p->addr))
|
|
return -EINVAL;
|
|
|
|
if ((unsigned long)p->addr & 0x01)
|
|
return -EINVAL;
|
|
|
|
/* Use the get_insn_slot() facility for correctness */
|
|
if (!(p->ainsn.insn = get_insn_slot()))
|
|
return -ENOMEM;
|
|
|
|
memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t));
|
|
|
|
get_instruction_type(&p->ainsn);
|
|
p->opcode = *p->addr;
|
|
return 0;
|
|
}
|
|
|
|
int __kprobes is_prohibited_opcode(kprobe_opcode_t *instruction)
|
|
{
|
|
switch (*(__u8 *) instruction) {
|
|
case 0x0c: /* bassm */
|
|
case 0x0b: /* bsm */
|
|
case 0x83: /* diag */
|
|
case 0x44: /* ex */
|
|
return -EINVAL;
|
|
}
|
|
switch (*(__u16 *) instruction) {
|
|
case 0x0101: /* pr */
|
|
case 0xb25a: /* bsa */
|
|
case 0xb240: /* bakr */
|
|
case 0xb258: /* bsg */
|
|
case 0xb218: /* pc */
|
|
case 0xb228: /* pt */
|
|
return -EINVAL;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void __kprobes get_instruction_type(struct arch_specific_insn *ainsn)
|
|
{
|
|
/* default fixup method */
|
|
ainsn->fixup = FIXUP_PSW_NORMAL;
|
|
|
|
/* save r1 operand */
|
|
ainsn->reg = (*ainsn->insn & 0xf0) >> 4;
|
|
|
|
/* save the instruction length (pop 5-5) in bytes */
|
|
switch (*(__u8 *) (ainsn->insn) >> 6) {
|
|
case 0:
|
|
ainsn->ilen = 2;
|
|
break;
|
|
case 1:
|
|
case 2:
|
|
ainsn->ilen = 4;
|
|
break;
|
|
case 3:
|
|
ainsn->ilen = 6;
|
|
break;
|
|
}
|
|
|
|
switch (*(__u8 *) ainsn->insn) {
|
|
case 0x05: /* balr */
|
|
case 0x0d: /* basr */
|
|
ainsn->fixup = FIXUP_RETURN_REGISTER;
|
|
/* if r2 = 0, no branch will be taken */
|
|
if ((*ainsn->insn & 0x0f) == 0)
|
|
ainsn->fixup |= FIXUP_BRANCH_NOT_TAKEN;
|
|
break;
|
|
case 0x06: /* bctr */
|
|
case 0x07: /* bcr */
|
|
ainsn->fixup = FIXUP_BRANCH_NOT_TAKEN;
|
|
break;
|
|
case 0x45: /* bal */
|
|
case 0x4d: /* bas */
|
|
ainsn->fixup = FIXUP_RETURN_REGISTER;
|
|
break;
|
|
case 0x47: /* bc */
|
|
case 0x46: /* bct */
|
|
case 0x86: /* bxh */
|
|
case 0x87: /* bxle */
|
|
ainsn->fixup = FIXUP_BRANCH_NOT_TAKEN;
|
|
break;
|
|
case 0x82: /* lpsw */
|
|
ainsn->fixup = FIXUP_NOT_REQUIRED;
|
|
break;
|
|
case 0xb2: /* lpswe */
|
|
if (*(((__u8 *) ainsn->insn) + 1) == 0xb2) {
|
|
ainsn->fixup = FIXUP_NOT_REQUIRED;
|
|
}
|
|
break;
|
|
case 0xa7: /* bras */
|
|
if ((*ainsn->insn & 0x0f) == 0x05) {
|
|
ainsn->fixup |= FIXUP_RETURN_REGISTER;
|
|
}
|
|
break;
|
|
case 0xc0:
|
|
if ((*ainsn->insn & 0x0f) == 0x00 /* larl */
|
|
|| (*ainsn->insn & 0x0f) == 0x05) /* brasl */
|
|
ainsn->fixup |= FIXUP_RETURN_REGISTER;
|
|
break;
|
|
case 0xeb:
|
|
if (*(((__u8 *) ainsn->insn) + 5 ) == 0x44 || /* bxhg */
|
|
*(((__u8 *) ainsn->insn) + 5) == 0x45) {/* bxleg */
|
|
ainsn->fixup = FIXUP_BRANCH_NOT_TAKEN;
|
|
}
|
|
break;
|
|
case 0xe3: /* bctg */
|
|
if (*(((__u8 *) ainsn->insn) + 5) == 0x46) {
|
|
ainsn->fixup = FIXUP_BRANCH_NOT_TAKEN;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
static int __kprobes swap_instruction(void *aref)
|
|
{
|
|
struct ins_replace_args *args = aref;
|
|
u32 *addr;
|
|
u32 instr;
|
|
int err = -EFAULT;
|
|
|
|
/*
|
|
* Text segment is read-only, hence we use stura to bypass dynamic
|
|
* address translation to exchange the instruction. Since stura
|
|
* always operates on four bytes, but we only want to exchange two
|
|
* bytes do some calculations to get things right. In addition we
|
|
* shall not cross any page boundaries (vmalloc area!) when writing
|
|
* the new instruction.
|
|
*/
|
|
addr = (u32 *)((unsigned long)args->ptr & -4UL);
|
|
if ((unsigned long)args->ptr & 2)
|
|
instr = ((*addr) & 0xffff0000) | args->new;
|
|
else
|
|
instr = ((*addr) & 0x0000ffff) | args->new << 16;
|
|
|
|
asm volatile(
|
|
" lra %1,0(%1)\n"
|
|
"0: stura %2,%1\n"
|
|
"1: la %0,0\n"
|
|
"2:\n"
|
|
EX_TABLE(0b,2b)
|
|
: "+d" (err)
|
|
: "a" (addr), "d" (instr)
|
|
: "memory", "cc");
|
|
|
|
return err;
|
|
}
|
|
|
|
void __kprobes arch_arm_kprobe(struct kprobe *p)
|
|
{
|
|
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
|
unsigned long status = kcb->kprobe_status;
|
|
struct ins_replace_args args;
|
|
|
|
args.ptr = p->addr;
|
|
args.old = p->opcode;
|
|
args.new = BREAKPOINT_INSTRUCTION;
|
|
|
|
kcb->kprobe_status = KPROBE_SWAP_INST;
|
|
stop_machine_run(swap_instruction, &args, NR_CPUS);
|
|
kcb->kprobe_status = status;
|
|
}
|
|
|
|
void __kprobes arch_disarm_kprobe(struct kprobe *p)
|
|
{
|
|
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
|
unsigned long status = kcb->kprobe_status;
|
|
struct ins_replace_args args;
|
|
|
|
args.ptr = p->addr;
|
|
args.old = BREAKPOINT_INSTRUCTION;
|
|
args.new = p->opcode;
|
|
|
|
kcb->kprobe_status = KPROBE_SWAP_INST;
|
|
stop_machine_run(swap_instruction, &args, NR_CPUS);
|
|
kcb->kprobe_status = status;
|
|
}
|
|
|
|
void __kprobes arch_remove_kprobe(struct kprobe *p)
|
|
{
|
|
mutex_lock(&kprobe_mutex);
|
|
free_insn_slot(p->ainsn.insn, 0);
|
|
mutex_unlock(&kprobe_mutex);
|
|
}
|
|
|
|
static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
|
|
{
|
|
per_cr_bits kprobe_per_regs[1];
|
|
|
|
memset(kprobe_per_regs, 0, sizeof(per_cr_bits));
|
|
regs->psw.addr = (unsigned long)p->ainsn.insn | PSW_ADDR_AMODE;
|
|
|
|
/* Set up the per control reg info, will pass to lctl */
|
|
kprobe_per_regs[0].em_instruction_fetch = 1;
|
|
kprobe_per_regs[0].starting_addr = (unsigned long)p->ainsn.insn;
|
|
kprobe_per_regs[0].ending_addr = (unsigned long)p->ainsn.insn + 1;
|
|
|
|
/* Set the PER control regs, turns on single step for this address */
|
|
__ctl_load(kprobe_per_regs, 9, 11);
|
|
regs->psw.mask |= PSW_MASK_PER;
|
|
regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK);
|
|
}
|
|
|
|
static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
|
|
{
|
|
kcb->prev_kprobe.kp = kprobe_running();
|
|
kcb->prev_kprobe.status = kcb->kprobe_status;
|
|
kcb->prev_kprobe.kprobe_saved_imask = kcb->kprobe_saved_imask;
|
|
memcpy(kcb->prev_kprobe.kprobe_saved_ctl, kcb->kprobe_saved_ctl,
|
|
sizeof(kcb->kprobe_saved_ctl));
|
|
}
|
|
|
|
static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb)
|
|
{
|
|
__get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp;
|
|
kcb->kprobe_status = kcb->prev_kprobe.status;
|
|
kcb->kprobe_saved_imask = kcb->prev_kprobe.kprobe_saved_imask;
|
|
memcpy(kcb->kprobe_saved_ctl, kcb->prev_kprobe.kprobe_saved_ctl,
|
|
sizeof(kcb->kprobe_saved_ctl));
|
|
}
|
|
|
|
static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
|
|
struct kprobe_ctlblk *kcb)
|
|
{
|
|
__get_cpu_var(current_kprobe) = p;
|
|
/* Save the interrupt and per flags */
|
|
kcb->kprobe_saved_imask = regs->psw.mask &
|
|
(PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK);
|
|
/* Save the control regs that govern PER */
|
|
__ctl_store(kcb->kprobe_saved_ctl, 9, 11);
|
|
}
|
|
|
|
/* Called with kretprobe_lock held */
|
|
void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
|
|
struct pt_regs *regs)
|
|
{
|
|
ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14];
|
|
|
|
/* Replace the return addr with trampoline addr */
|
|
regs->gprs[14] = (unsigned long)&kretprobe_trampoline;
|
|
}
|
|
|
|
static int __kprobes kprobe_handler(struct pt_regs *regs)
|
|
{
|
|
struct kprobe *p;
|
|
int ret = 0;
|
|
unsigned long *addr = (unsigned long *)
|
|
((regs->psw.addr & PSW_ADDR_INSN) - 2);
|
|
struct kprobe_ctlblk *kcb;
|
|
|
|
/*
|
|
* We don't want to be preempted for the entire
|
|
* duration of kprobe processing
|
|
*/
|
|
preempt_disable();
|
|
kcb = get_kprobe_ctlblk();
|
|
|
|
/* Check we're not actually recursing */
|
|
if (kprobe_running()) {
|
|
p = get_kprobe(addr);
|
|
if (p) {
|
|
if (kcb->kprobe_status == KPROBE_HIT_SS &&
|
|
*p->ainsn.insn == BREAKPOINT_INSTRUCTION) {
|
|
regs->psw.mask &= ~PSW_MASK_PER;
|
|
regs->psw.mask |= kcb->kprobe_saved_imask;
|
|
goto no_kprobe;
|
|
}
|
|
/* We have reentered the kprobe_handler(), since
|
|
* another probe was hit while within the handler.
|
|
* We here save the original kprobes variables and
|
|
* just single step on the instruction of the new probe
|
|
* without calling any user handlers.
|
|
*/
|
|
save_previous_kprobe(kcb);
|
|
set_current_kprobe(p, regs, kcb);
|
|
kprobes_inc_nmissed_count(p);
|
|
prepare_singlestep(p, regs);
|
|
kcb->kprobe_status = KPROBE_REENTER;
|
|
return 1;
|
|
} else {
|
|
p = __get_cpu_var(current_kprobe);
|
|
if (p->break_handler && p->break_handler(p, regs)) {
|
|
goto ss_probe;
|
|
}
|
|
}
|
|
goto no_kprobe;
|
|
}
|
|
|
|
p = get_kprobe(addr);
|
|
if (!p)
|
|
/*
|
|
* No kprobe at this address. The fault has not been
|
|
* caused by a kprobe breakpoint. The race of breakpoint
|
|
* vs. kprobe remove does not exist because on s390 we
|
|
* use stop_machine_run to arm/disarm the breakpoints.
|
|
*/
|
|
goto no_kprobe;
|
|
|
|
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
|
|
set_current_kprobe(p, regs, kcb);
|
|
if (p->pre_handler && p->pre_handler(p, regs))
|
|
/* handler has already set things up, so skip ss setup */
|
|
return 1;
|
|
|
|
ss_probe:
|
|
prepare_singlestep(p, regs);
|
|
kcb->kprobe_status = KPROBE_HIT_SS;
|
|
return 1;
|
|
|
|
no_kprobe:
|
|
preempt_enable_no_resched();
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* Function return probe trampoline:
|
|
* - init_kprobes() establishes a probepoint here
|
|
* - When the probed function returns, this probe
|
|
* causes the handlers to fire
|
|
*/
|
|
static void __used kretprobe_trampoline_holder(void)
|
|
{
|
|
asm volatile(".global kretprobe_trampoline\n"
|
|
"kretprobe_trampoline: bcr 0,0\n");
|
|
}
|
|
|
|
/*
|
|
* Called when the probe at kretprobe trampoline is hit
|
|
*/
|
|
static int __kprobes trampoline_probe_handler(struct kprobe *p,
|
|
struct pt_regs *regs)
|
|
{
|
|
struct kretprobe_instance *ri = NULL;
|
|
struct hlist_head *head, empty_rp;
|
|
struct hlist_node *node, *tmp;
|
|
unsigned long flags, orig_ret_address = 0;
|
|
unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
|
|
|
|
INIT_HLIST_HEAD(&empty_rp);
|
|
spin_lock_irqsave(&kretprobe_lock, flags);
|
|
head = kretprobe_inst_table_head(current);
|
|
|
|
/*
|
|
* It is possible to have multiple instances associated with a given
|
|
* task either because an multiple functions in the call path
|
|
* have a return probe installed on them, and/or more then one return
|
|
* return probe was registered for a target function.
|
|
*
|
|
* We can handle this because:
|
|
* - instances are always inserted at the head of the list
|
|
* - when multiple return probes are registered for the same
|
|
* function, the first instance's ret_addr will point to the
|
|
* real return address, and all the rest will point to
|
|
* kretprobe_trampoline
|
|
*/
|
|
hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
|
|
if (ri->task != current)
|
|
/* another task is sharing our hash bucket */
|
|
continue;
|
|
|
|
if (ri->rp && ri->rp->handler)
|
|
ri->rp->handler(ri, regs);
|
|
|
|
orig_ret_address = (unsigned long)ri->ret_addr;
|
|
recycle_rp_inst(ri, &empty_rp);
|
|
|
|
if (orig_ret_address != trampoline_address) {
|
|
/*
|
|
* This is the real return address. Any other
|
|
* instances associated with this task are for
|
|
* other calls deeper on the call stack
|
|
*/
|
|
break;
|
|
}
|
|
}
|
|
kretprobe_assert(ri, orig_ret_address, trampoline_address);
|
|
regs->psw.addr = orig_ret_address | PSW_ADDR_AMODE;
|
|
|
|
reset_current_kprobe();
|
|
spin_unlock_irqrestore(&kretprobe_lock, flags);
|
|
preempt_enable_no_resched();
|
|
|
|
hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
|
|
hlist_del(&ri->hlist);
|
|
kfree(ri);
|
|
}
|
|
/*
|
|
* By returning a non-zero value, we are telling
|
|
* kprobe_handler() that we don't want the post_handler
|
|
* to run (and have re-enabled preemption)
|
|
*/
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Called after single-stepping. p->addr is the address of the
|
|
* instruction whose first byte has been replaced by the "breakpoint"
|
|
* instruction. To avoid the SMP problems that can occur when we
|
|
* temporarily put back the original opcode to single-step, we
|
|
* single-stepped a copy of the instruction. The address of this
|
|
* copy is p->ainsn.insn.
|
|
*/
|
|
static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs)
|
|
{
|
|
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
|
|
|
regs->psw.addr &= PSW_ADDR_INSN;
|
|
|
|
if (p->ainsn.fixup & FIXUP_PSW_NORMAL)
|
|
regs->psw.addr = (unsigned long)p->addr +
|
|
((unsigned long)regs->psw.addr -
|
|
(unsigned long)p->ainsn.insn);
|
|
|
|
if (p->ainsn.fixup & FIXUP_BRANCH_NOT_TAKEN)
|
|
if ((unsigned long)regs->psw.addr -
|
|
(unsigned long)p->ainsn.insn == p->ainsn.ilen)
|
|
regs->psw.addr = (unsigned long)p->addr + p->ainsn.ilen;
|
|
|
|
if (p->ainsn.fixup & FIXUP_RETURN_REGISTER)
|
|
regs->gprs[p->ainsn.reg] = ((unsigned long)p->addr +
|
|
(regs->gprs[p->ainsn.reg] -
|
|
(unsigned long)p->ainsn.insn))
|
|
| PSW_ADDR_AMODE;
|
|
|
|
regs->psw.addr |= PSW_ADDR_AMODE;
|
|
/* turn off PER mode */
|
|
regs->psw.mask &= ~PSW_MASK_PER;
|
|
/* Restore the original per control regs */
|
|
__ctl_load(kcb->kprobe_saved_ctl, 9, 11);
|
|
regs->psw.mask |= kcb->kprobe_saved_imask;
|
|
}
|
|
|
|
static int __kprobes post_kprobe_handler(struct pt_regs *regs)
|
|
{
|
|
struct kprobe *cur = kprobe_running();
|
|
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
|
|
|
if (!cur)
|
|
return 0;
|
|
|
|
if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) {
|
|
kcb->kprobe_status = KPROBE_HIT_SSDONE;
|
|
cur->post_handler(cur, regs, 0);
|
|
}
|
|
|
|
resume_execution(cur, regs);
|
|
|
|
/*Restore back the original saved kprobes variables and continue. */
|
|
if (kcb->kprobe_status == KPROBE_REENTER) {
|
|
restore_previous_kprobe(kcb);
|
|
goto out;
|
|
}
|
|
reset_current_kprobe();
|
|
out:
|
|
preempt_enable_no_resched();
|
|
|
|
/*
|
|
* if somebody else is singlestepping across a probe point, psw mask
|
|
* will have PER set, in which case, continue the remaining processing
|
|
* of do_single_step, as if this is not a probe hit.
|
|
*/
|
|
if (regs->psw.mask & PSW_MASK_PER) {
|
|
return 0;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
|
|
{
|
|
struct kprobe *cur = kprobe_running();
|
|
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
|
const struct exception_table_entry *entry;
|
|
|
|
switch(kcb->kprobe_status) {
|
|
case KPROBE_SWAP_INST:
|
|
/* We are here because the instruction replacement failed */
|
|
return 0;
|
|
case KPROBE_HIT_SS:
|
|
case KPROBE_REENTER:
|
|
/*
|
|
* We are here because the instruction being single
|
|
* stepped caused a page fault. We reset the current
|
|
* kprobe and the nip points back to the probe address
|
|
* and allow the page fault handler to continue as a
|
|
* normal page fault.
|
|
*/
|
|
regs->psw.addr = (unsigned long)cur->addr | PSW_ADDR_AMODE;
|
|
regs->psw.mask &= ~PSW_MASK_PER;
|
|
regs->psw.mask |= kcb->kprobe_saved_imask;
|
|
if (kcb->kprobe_status == KPROBE_REENTER)
|
|
restore_previous_kprobe(kcb);
|
|
else
|
|
reset_current_kprobe();
|
|
preempt_enable_no_resched();
|
|
break;
|
|
case KPROBE_HIT_ACTIVE:
|
|
case KPROBE_HIT_SSDONE:
|
|
/*
|
|
* We increment the nmissed count for accounting,
|
|
* we can also use npre/npostfault count for accouting
|
|
* these specific fault cases.
|
|
*/
|
|
kprobes_inc_nmissed_count(cur);
|
|
|
|
/*
|
|
* We come here because instructions in the pre/post
|
|
* handler caused the page_fault, this could happen
|
|
* if handler tries to access user space by
|
|
* copy_from_user(), get_user() etc. Let the
|
|
* user-specified handler try to fix it first.
|
|
*/
|
|
if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr))
|
|
return 1;
|
|
|
|
/*
|
|
* In case the user-specified fault handler returned
|
|
* zero, try to fix up.
|
|
*/
|
|
entry = search_exception_tables(regs->psw.addr & PSW_ADDR_INSN);
|
|
if (entry) {
|
|
regs->psw.addr = entry->fixup | PSW_ADDR_AMODE;
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* fixup_exception() could not handle it,
|
|
* Let do_page_fault() fix it.
|
|
*/
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Wrapper routine to for handling exceptions.
|
|
*/
|
|
int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
|
|
unsigned long val, void *data)
|
|
{
|
|
struct die_args *args = (struct die_args *)data;
|
|
int ret = NOTIFY_DONE;
|
|
|
|
switch (val) {
|
|
case DIE_BPT:
|
|
if (kprobe_handler(args->regs))
|
|
ret = NOTIFY_STOP;
|
|
break;
|
|
case DIE_SSTEP:
|
|
if (post_kprobe_handler(args->regs))
|
|
ret = NOTIFY_STOP;
|
|
break;
|
|
case DIE_TRAP:
|
|
/* kprobe_running() needs smp_processor_id() */
|
|
preempt_disable();
|
|
if (kprobe_running() &&
|
|
kprobe_fault_handler(args->regs, args->trapnr))
|
|
ret = NOTIFY_STOP;
|
|
preempt_enable();
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
|
|
{
|
|
struct jprobe *jp = container_of(p, struct jprobe, kp);
|
|
unsigned long addr;
|
|
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
|
|
|
memcpy(&kcb->jprobe_saved_regs, regs, sizeof(struct pt_regs));
|
|
|
|
/* setup return addr to the jprobe handler routine */
|
|
regs->psw.addr = (unsigned long)(jp->entry) | PSW_ADDR_AMODE;
|
|
|
|
/* r14 is the function return address */
|
|
kcb->jprobe_saved_r14 = (unsigned long)regs->gprs[14];
|
|
/* r15 is the stack pointer */
|
|
kcb->jprobe_saved_r15 = (unsigned long)regs->gprs[15];
|
|
addr = (unsigned long)kcb->jprobe_saved_r15;
|
|
|
|
memcpy(kcb->jprobes_stack, (kprobe_opcode_t *) addr,
|
|
MIN_STACK_SIZE(addr));
|
|
return 1;
|
|
}
|
|
|
|
void __kprobes jprobe_return(void)
|
|
{
|
|
asm volatile(".word 0x0002");
|
|
}
|
|
|
|
void __kprobes jprobe_return_end(void)
|
|
{
|
|
asm volatile("bcr 0,0");
|
|
}
|
|
|
|
int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
|
|
{
|
|
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
|
|
unsigned long stack_addr = (unsigned long)(kcb->jprobe_saved_r15);
|
|
|
|
/* Put the regs back */
|
|
memcpy(regs, &kcb->jprobe_saved_regs, sizeof(struct pt_regs));
|
|
/* put the stack back */
|
|
memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack,
|
|
MIN_STACK_SIZE(stack_addr));
|
|
preempt_enable_no_resched();
|
|
return 1;
|
|
}
|
|
|
|
static struct kprobe trampoline_p = {
|
|
.addr = (kprobe_opcode_t *) & kretprobe_trampoline,
|
|
.pre_handler = trampoline_probe_handler
|
|
};
|
|
|
|
int __init arch_init_kprobes(void)
|
|
{
|
|
return register_kprobe(&trampoline_p);
|
|
}
|
|
|
|
int __kprobes arch_trampoline_kprobe(struct kprobe *p)
|
|
{
|
|
if (p->addr == (kprobe_opcode_t *) & kretprobe_trampoline)
|
|
return 1;
|
|
return 0;
|
|
}
|