From: Harvey Harrison <harvey.harrison@gmail.com>
To: Ingo Molnar <mingo@elte.hu>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: FInal kprobes rollup patches
Date: Sat, 15 Dec 2007 00:45:50 -0800 [thread overview]
Message-ID: <1197708350.898.87.camel@brick> (raw)
>From f87fb3155500f85ffbafc01d6f5b8dc2a3f6184c Mon Sep 17 00:00:00 2001
From: Harvey Harrison <harvey.harrison@gmail.com>
Date: Fri, 14 Dec 2007 22:02:51 -0800
Subject: [PATCH] [RFC] x86: kprobes unification
Further unification work. There is a possible behavior
change on X86_32 here.
is_IF_modifier(p->opcode)
to
is_IF_modifier(p->ainsn.insn)
Which should be equivalent, but is not purely cosmetic as
the rest of the unification so far.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
---
arch/x86/kernel/kprobes_32.c | 43 +++++++++++++++++++++--------
arch/x86/kernel/kprobes_64.c | 60 +++++++++++++++++++++++++++++++++++-------
2 files changed, 81 insertions(+), 22 deletions(-)
diff --git a/arch/x86/kernel/kprobes_32.c b/arch/x86/kernel/kprobes_32.c
index 878b0c4..21ac86f 100644
--- a/arch/x86/kernel/kprobes_32.c
+++ b/arch/x86/kernel/kprobes_32.c
@@ -220,15 +220,21 @@ retry:
/*
* returns non-zero if opcode modifies the interrupt flag.
*/
-static int __kprobes is_IF_modifier(kprobe_opcode_t opcode)
+static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
{
- switch (opcode) {
+ switch (*insn) {
case 0xfa: /* cli */
case 0xfb: /* sti */
case 0xcf: /* iret/iretd */
case 0x9d: /* popf/popfd */
return 1;
}
+
+#ifdef CONFIG_X86_64
+ /* REX prefix */
+ if (*insn >= 0x40 && *insn <= 0x4f && *++insn == 0xcf)
+ return 1;
+#endif
return 0;
}
@@ -370,7 +376,7 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
__get_cpu_var(current_kprobe) = p;
kcb->kprobe_saved_flags = kcb->kprobe_old_flags
= (regs->flags & (TF_MASK | IF_MASK));
- if (is_IF_modifier(p->opcode))
+ if (is_IF_modifier(p->ainsn.insn))
kcb->kprobe_saved_flags &= ~IF_MASK;
}
@@ -410,10 +416,9 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
- unsigned long *sara = (unsigned long *)®s->sp;
+ unsigned long *sara = ®s->sp;
ri->ret_addr = (kprobe_opcode_t *) *sara;
-
/* Replace the return addr with trampoline addr */
*sara = (unsigned long) &kretprobe_trampoline;
}
@@ -528,8 +533,9 @@ no_kprobe:
* here. When a retprobed function returns, this probe is hit and
* trampoline_probe_handler() runs, calling the kretprobe's handler.
*/
- void __kprobes kretprobe_trampoline_holder(void)
- {
+void __kprobes kretprobe_trampoline_holder(void)
+{
+#ifdef CONFIG_X86_32
asm volatile ( ".global kretprobe_trampoline\n"
"kretprobe_trampoline: \n"
" pushf\n"
@@ -563,6 +569,11 @@ no_kprobe:
" addl $20, %esp\n"
" popf\n"
" ret\n");
+#else
+ asm volatile ( ".global kretprobe_trampoline\n"
+ "kretprobe_trampoline: \n"
+ "nop\n");
+#endif
}
/*
@@ -658,12 +669,20 @@ void *__kprobes trampoline_handler(struct pt_regs *regs)
static void __kprobes resume_execution(struct kprobe *p,
struct pt_regs *regs, struct kprobe_ctlblk *kcb)
{
- unsigned long *tos = (unsigned long *)®s->sp;
+ unsigned long *tos = ®s->sp;
+ unsigned long next_rip = 0;
unsigned long copy_ip = (unsigned long)p->ainsn.insn;
unsigned long orig_ip = (unsigned long)p->addr;
+ kprobe_opcode_t *insn = p->ainsn.insn;
+
+#ifdef CONFIG_X86_64
+ /*skip the REX prefix*/
+ if (*insn >= 0x40 && *insn <= 0x4f)
+ insn++;
+#endif
regs->flags &= ~TF_MASK;
- switch (p->ainsn.insn[0]) {
+ switch (*insn) {
case 0x9c: /* pushfl */
*tos &= ~(TF_MASK | IF_MASK);
*tos |= kcb->kprobe_old_flags;
@@ -684,7 +703,7 @@ static void __kprobes resume_execution(struct kprobe *p,
*tos = orig_ip + (*tos - copy_ip);
goto no_change;
case 0xff:
- if ((p->ainsn.insn[1] & 0x30) == 0x10) {
+ if ((insn[1] & 0x30) == 0x10) {
/*
* call absolute, indirect
* Fix return addr; ip is correct.
@@ -692,8 +711,8 @@ static void __kprobes resume_execution(struct kprobe *p,
*/
*tos = orig_ip + (*tos - copy_ip);
goto no_change;
- } else if (((p->ainsn.insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
- ((p->ainsn.insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
+ } else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
+ ((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
/* ip is correct. And this is boostable */
p->ainsn.boostable = 1;
goto no_change;
diff --git a/arch/x86/kernel/kprobes_64.c b/arch/x86/kernel/kprobes_64.c
index b437f7a..9bf6ebe 100644
--- a/arch/x86/kernel/kprobes_64.c
+++ b/arch/x86/kernel/kprobes_64.c
@@ -236,8 +236,11 @@ static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
return 1;
}
+#ifdef CONFIG_X86_64
+ /* REX prefix */
if (*insn >= 0x40 && *insn <= 0x4f && *++insn == 0xcf)
return 1;
+#endif
return 0;
}
@@ -419,7 +422,7 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
- unsigned long *sara = (unsigned long *)regs->sp;
+ unsigned long *sara = ®s->sp;
ri->ret_addr = (kprobe_opcode_t *) *sara;
/* Replace the return addr with trampoline addr */
@@ -535,12 +538,48 @@ no_kprobe:
* here. When a retprobed function returns, this probe is hit and
* trampoline_probe_handler() runs, calling the kretprobe's handler.
*/
- void kretprobe_trampoline_holder(void)
- {
- asm volatile ( ".global kretprobe_trampoline\n"
- "kretprobe_trampoline: \n"
- "nop\n");
- }
+void kretprobe_trampoline_holder(void)
+{
+#ifdef CONFIG_X86_32
+ asm volatile ( ".global kretprobe_trampoline\n"
+ "kretprobe_trampoline: \n"
+ " pushf\n"
+ /* skip cs, ip, orig_ax */
+ " subl $12, %esp\n"
+ " pushl %fs\n"
+ " pushl %ds\n"
+ " pushl %es\n"
+ " pushl %eax\n"
+ " pushl %ebp\n"
+ " pushl %edi\n"
+ " pushl %esi\n"
+ " pushl %edx\n"
+ " pushl %ecx\n"
+ " pushl %ebx\n"
+ " movl %esp, %eax\n"
+ " call trampoline_handler\n"
+ /* move flags to cs */
+ " movl 52(%esp), %edx\n"
+ " movl %edx, 48(%esp)\n"
+ /* save true return address on flags */
+ " movl %eax, 52(%esp)\n"
+ " popl %ebx\n"
+ " popl %ecx\n"
+ " popl %edx\n"
+ " popl %esi\n"
+ " popl %edi\n"
+ " popl %ebp\n"
+ " popl %eax\n"
+ /* skip ip, orig_ax, es, ds, fs */
+ " addl $20, %esp\n"
+ " popf\n"
+ " ret\n");
+#else
+ asm volatile ( ".global kretprobe_trampoline\n"
+ "kretprobe_trampoline: \n"
+ "nop\n");
+#endif
+}
/*
* Called when we hit the probe point at kretprobe_trampoline
@@ -634,16 +673,19 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
static void __kprobes resume_execution(struct kprobe *p,
struct pt_regs *regs, struct kprobe_ctlblk *kcb)
{
- unsigned long *tos = (unsigned long *)regs->sp;
+ unsigned long *tos = ®s->sp;
unsigned long next_rip = 0;
unsigned long copy_ip = (unsigned long)p->ainsn.insn;
unsigned long orig_ip = (unsigned long)p->addr;
kprobe_opcode_t *insn = p->ainsn.insn;
+#ifdef CONFIG_X86_64
/*skip the REX prefix*/
if (*insn >= 0x40 && *insn <= 0x4f)
insn++;
+#endif
+ regs->flags &= ~TF_MASK;
switch (*insn) {
case 0x9c: /* pushfl */
*tos &= ~(TF_MASK | IF_MASK);
@@ -653,7 +695,6 @@ static void __kprobes resume_execution(struct kprobe *p,
case 0xcb:
case 0xc2:
case 0xca:
- regs->flags &= ~TF_MASK;
/* ip is already adjusted, no more changes required*/
return;
case 0xe8: /* call relative - Fix return addr */
@@ -678,7 +719,6 @@ static void __kprobes resume_execution(struct kprobe *p,
break;
}
- regs->flags &= ~TF_MASK;
if (next_rip) {
regs->ip = next_rip;
} else {
--
1.5.4.rc0.1083.gf568
>From 4a048bf0c67558b8170dcde7c8395f6c35592f0b Mon Sep 17 00:00:00 2001
From: Harvey Harrison <harvey.harrison@gmail.com>
Date: Fri, 14 Dec 2007 22:52:44 -0800
Subject: [PATCH] x86: Move some exception fixup logic in kprobes_{32|64}.c
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
---
arch/x86/kernel/kprobes_32.c | 21 ++++++++++++++++++---
arch/x86/kernel/kprobes_64.c | 21 ++++++++++++++++-----
2 files changed, 34 insertions(+), 8 deletions(-)
diff --git a/arch/x86/kernel/kprobes_32.c b/arch/x86/kernel/kprobes_32.c
index 21ac86f..a2b5ca7 100644
--- a/arch/x86/kernel/kprobes_32.c
+++ b/arch/x86/kernel/kprobes_32.c
@@ -533,7 +533,7 @@ no_kprobe:
* here. When a retprobed function returns, this probe is hit and
* trampoline_probe_handler() runs, calling the kretprobe's handler.
*/
-void __kprobes kretprobe_trampoline_holder(void)
+void kretprobe_trampoline_holder(void)
{
#ifdef CONFIG_X86_32
asm volatile ( ".global kretprobe_trampoline\n"
@@ -787,6 +787,9 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+#ifdef CONFIG_X86_64
+ const struct exception_table_entry *fixup;
+#endif
switch(kcb->kprobe_status) {
case KPROBE_HIT_SS:
@@ -829,11 +832,18 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* In case the user-specified fault handler returned
* zero, try to fix up.
*/
+#ifdef CONFIG_X86_32
if (fixup_exception(regs))
return 1;
-
+#else
+ fixup = search_exception_tables(regs->ip);
+ if (fixup) {
+ regs->ip = fixup->fixup;
+ return 1;
+ }
+#endif
/*
- * fixup_exception() could not handle it,
+ * Exception couldn't be fixed up,
* Let do_page_fault() fix it.
*/
break;
@@ -852,8 +862,13 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
struct die_args *args = (struct die_args *)data;
int ret = NOTIFY_DONE;
+#ifdef CONFIG_X86_32
if (args->regs && user_mode_vm(args->regs))
return ret;
+#else
+ if (args->regs && user_mode(args->regs))
+ return ret;
+#endif
switch (val) {
case DIE_INT3:
diff --git a/arch/x86/kernel/kprobes_64.c b/arch/x86/kernel/kprobes_64.c
index 9bf6ebe..705cb99 100644
--- a/arch/x86/kernel/kprobes_64.c
+++ b/arch/x86/kernel/kprobes_64.c
@@ -769,7 +769,9 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+#ifdef CONFIG_X86_64
const struct exception_table_entry *fixup;
+#endif
switch(kcb->kprobe_status) {
case KPROBE_HIT_SS:
@@ -812,14 +814,18 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* In case the user-specified fault handler returned
* zero, try to fix up.
*/
+#ifdef CONFIG_X86_32
+ if (fixup_exception(regs))
+ return 1;
+#else
fixup = search_exception_tables(regs->ip);
if (fixup) {
regs->ip = fixup->fixup;
return 1;
}
-
+#endif
/*
- * fixup() could not handle it,
+ * Exception couldn't be fixed up,
* Let do_page_fault() fix it.
*/
break;
@@ -838,8 +844,13 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
struct die_args *args = (struct die_args *)data;
int ret = NOTIFY_DONE;
+#ifdef CONFIG_X86_32
+ if (args->regs && user_mode_vm(args->regs))
+ return ret;
+#else
if (args->regs && user_mode(args->regs))
return ret;
+#endif
switch (val) {
case DIE_INT3:
@@ -871,7 +882,7 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
kcb->jprobe_saved_regs = *regs;
- kcb->jprobe_saved_sp = (long *) regs->sp;
+ kcb->jprobe_saved_sp = ®s->sp;
addr = (unsigned long)(kcb->jprobe_saved_sp);
/*
* As Linus pointed out, gcc assumes that the callee
@@ -916,12 +927,12 @@ int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
struct jprobe *jp = container_of(p, struct jprobe, kp);
if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) {
- if ((long *)regs->sp != kcb->jprobe_saved_sp) {
+ if (®s->sp != kcb->jprobe_saved_sp) {
struct pt_regs *saved_regs =
container_of(kcb->jprobe_saved_sp,
struct pt_regs, sp);
printk("current sp %p does not match saved sp %p\n",
- (long *)regs->sp, kcb->jprobe_saved_sp);
+ ®s->sp, kcb->jprobe_saved_sp);
printk("Saved registers for jprobe %p\n", jp);
show_registers(saved_regs);
printk("Current registers\n");
--
1.5.4.rc0.1083.gf568
>From 83fde2864abcc34ef8bc575a22b5f8e76477b64b Mon Sep 17 00:00:00 2001
From: Harvey Harrison <harvey.harrison@gmail.com>
Date: Fri, 14 Dec 2007 22:56:50 -0800
Subject: [PATCH] x86: Duplicate some instruction IP logic
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
---
arch/x86/kernel/kprobes_32.c | 8 ++++++++
arch/x86/kernel/kprobes_64.c | 22 +++++++++++++++++++++-
2 files changed, 29 insertions(+), 1 deletions(-)
diff --git a/arch/x86/kernel/kprobes_32.c b/arch/x86/kernel/kprobes_32.c
index a2b5ca7..23fb9ae 100644
--- a/arch/x86/kernel/kprobes_32.c
+++ b/arch/x86/kernel/kprobes_32.c
@@ -721,6 +721,7 @@ static void __kprobes resume_execution(struct kprobe *p,
break;
}
+#ifdef CONFIG_X86_32
if (p->ainsn.boostable == 0) {
if ((regs->ip > copy_ip) &&
(regs->ip - copy_ip) + 5 < (MAX_INSN_SIZE + 1)) {
@@ -739,6 +740,13 @@ static void __kprobes resume_execution(struct kprobe *p,
regs->ip = orig_ip + (regs->ip - copy_ip);
no_change:
+#else
+ if (next_rip) {
+ regs->ip = next_rip;
+ } else {
+ regs->ip = orig_ip + (regs->ip - copy_ip);
+ }
+#endif
restore_btf();
}
diff --git a/arch/x86/kernel/kprobes_64.c b/arch/x86/kernel/kprobes_64.c
index 705cb99..f9cede4 100644
--- a/arch/x86/kernel/kprobes_64.c
+++ b/arch/x86/kernel/kprobes_64.c
@@ -719,12 +719,32 @@ static void __kprobes resume_execution(struct kprobe *p,
break;
}
+#ifdef CONFIG_X86_32
+ if (p->ainsn.boostable == 0) {
+ if ((regs->ip > copy_ip) &&
+ (regs->ip - copy_ip) + 5 < (MAX_INSN_SIZE + 1)) {
+ /*
+ * These instructions can be executed directly if it
+ * jumps back to correct address.
+ */
+ set_jmp_op((void *)regs->ip,
+ (void *)orig_ip + (regs->ip - copy_ip));
+ p->ainsn.boostable = 1;
+ } else {
+ p->ainsn.boostable = -1;
+ }
+ }
+
+ regs->ip = orig_ip + (regs->ip - copy_ip);
+
+no_change:
+#else
if (next_rip) {
regs->ip = next_rip;
} else {
regs->ip = orig_ip + (regs->ip - copy_ip);
}
-
+#endif
restore_btf();
}
--
1.5.4.rc0.1083.gf568
>From 323525be495dc545158fe43e072523d994253c39 Mon Sep 17 00:00:00 2001
From: Harvey Harrison <harvey.harrison@gmail.com>
Date: Sat, 15 Dec 2007 00:28:58 -0800
Subject: [PATCH] x86: Uglify kprobes_{32|64}.c before final unification
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
---
arch/x86/kernel/kprobes_32.c | 92 ++++++++++++++++++++++++++------
arch/x86/kernel/kprobes_64.c | 118 ++++++++++++++++++++++++++++++++++-------
2 files changed, 172 insertions(+), 38 deletions(-)
diff --git a/arch/x86/kernel/kprobes_32.c b/arch/x86/kernel/kprobes_32.c
index 23fb9ae..cb836ce 100644
--- a/arch/x86/kernel/kprobes_32.c
+++ b/arch/x86/kernel/kprobes_32.c
@@ -16,15 +16,6 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) IBM Corporation, 2002, 2004
- *
- * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
- * Probes initial implementation ( includes contributions from
- * Rusty Russell).
- * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
- * interface to access function arguments.
- * 2005-May Hien Nguyen <hien@us.ibm.com>, Jim Keniston
- * <jkenisto@us.ibm.com> and Prasanna S Panchamukhi
- * <prasanna@in.ibm.com> added function-return probes.
*/
#include <linux/kprobes.h>
@@ -350,7 +341,11 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
mutex_lock(&kprobe_mutex);
+#ifdef CONFIG_X86_32
free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1));
+#else
+ free_insn_slot(p->ainsn.insn, 0);
+#endif
mutex_unlock(&kprobe_mutex);
}
@@ -471,7 +466,11 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
* another cpu right after we hit, no further
* handling of this interrupt is appropriate
*/
+#ifdef CONFIG_X86_32
regs->ip -= sizeof(kprobe_opcode_t);
+#else
+ regs->ip = (unsigned long)addr;
+#endif
ret = 1;
goto no_kprobe;
}
@@ -495,7 +494,11 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
* Back up over the (now missing) int3 and run
* the original instruction.
*/
+#ifdef CONFIG_X86_32
regs->ip -= sizeof(kprobe_opcode_t);
+#else
+ regs->ip = (unsigned long)addr;
+#endif
ret = 1;
}
/* Not one of ours: let kernel handle it */
@@ -510,7 +513,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
return 1;
ss_probe:
-#if !defined(CONFIG_PREEMPT) || defined(CONFIG_PM)
+#if defined(CONFIG_X86_32) && (!defined(CONFIG_PREEMPT) || defined(CONFIG_PM))
if (p->ainsn.boostable == 1 && !p->post_handler){
/* Boost up -- we can execute copied instructions directly */
reset_current_kprobe();
@@ -579,7 +582,11 @@ void kretprobe_trampoline_holder(void)
/*
* Called when we hit the probe point at kretprobe_trampoline
*/
+#ifdef CONFIG_X86_32
void *__kprobes trampoline_handler(struct pt_regs *regs)
+#else
+int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
+#endif
{
struct kretprobe_instance *ri = NULL;
struct hlist_head *head, empty_rp;
@@ -590,11 +597,12 @@ void *__kprobes trampoline_handler(struct pt_regs *regs)
INIT_HLIST_HEAD(&empty_rp);
spin_lock_irqsave(&kretprobe_lock, flags);
head = kretprobe_inst_table_head(current);
+#ifdef CONFIG_X86_32
/* fixup registers */
regs->cs = __KERNEL_CS | get_kernel_rpl();
regs->ip = trampoline_address;
regs->orig_ax = 0xffffffff;
-
+#endif
/*
* It is possible to have multiple instances associated with a given
* task either because an multiple functions in the call path
@@ -612,14 +620,17 @@ void *__kprobes trampoline_handler(struct pt_regs *regs)
if (ri->task != current)
/* another task is sharing our hash bucket */
continue;
-
- if (ri->rp && ri->rp->handler){
+#ifdef CONFIG_X86_32
+ if (ri->rp && ri->rp->handler) {
__get_cpu_var(current_kprobe) = &ri->rp->kp;
get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
ri->rp->handler(ri, regs);
__get_cpu_var(current_kprobe) = NULL;
}
-
+#else
+ if (ri->rp && ri->rp->handler)
+ ri->rp->handler(ri, regs);
+#endif
orig_ret_address = (unsigned long)ri->ret_addr;
recycle_rp_inst(ri, &empty_rp);
@@ -633,13 +644,29 @@ void *__kprobes trampoline_handler(struct pt_regs *regs)
}
kretprobe_assert(ri, orig_ret_address, trampoline_address);
+#ifdef CONFIG_X86_64
+ regs->ip = orig_ret_address;
+ reset_current_kprobe();
+#endif
spin_unlock_irqrestore(&kretprobe_lock, flags);
-
+#ifdef CONFIG_X86_64
+ preempt_enable_no_resched();
+#endif
hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
kfree(ri);
}
+
+#ifdef CONFIG_X86_32
return (void*)orig_ret_address;
+#else
+ /*
+ * 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;
+#endif
}
/*
@@ -687,22 +714,29 @@ static void __kprobes resume_execution(struct kprobe *p,
*tos &= ~(TF_MASK | IF_MASK);
*tos |= kcb->kprobe_old_flags;
break;
- case 0xc2: /* iret/ret/lret */
+ case 0xc2: /* ret/lret */
case 0xc3:
case 0xca:
case 0xcb:
- case 0xcf:
- case 0xea: /* jmp absolute -- ip is correct */
+#ifdef CONFIG_X86_32
+ case 0xcf: /* iret */
/* ip is already adjusted, no more changes required */
p->ainsn.boostable = 1;
goto no_change;
+#else
+ /* ip is already adjusted, no more changes required*/
+ return;
+#endif
case 0xe8: /* call relative - Fix return addr */
*tos = orig_ip + (*tos - copy_ip);
break;
+#ifdef CONFIG_X86_32
case 0x9a: /* call absolute -- same as call absolute, indirect */
*tos = orig_ip + (*tos - copy_ip);
goto no_change;
+#endif
case 0xff:
+#ifdef CONFIG_X86_32
if ((insn[1] & 0x30) == 0x10) {
/*
* call absolute, indirect
@@ -717,6 +751,28 @@ static void __kprobes resume_execution(struct kprobe *p,
p->ainsn.boostable = 1;
goto no_change;
}
+#else
+ if ((insn[1] & 0x30) == 0x10) {
+ /* call absolute, indirect */
+ /* Fix return addr; ip is correct. */
+ next_rip = regs->ip;
+ *tos = orig_ip + (*tos - copy_ip);
+ } else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
+ ((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
+ /* ip is correct. */
+ next_rip = regs->ip;
+ }
+#endif
+ break;
+ case 0xea: /* jmp absolute -- ip is correct */
+#ifdef CONFIG_X86_32
+ /* ip is already adjusted, no more changes required */
+ p->ainsn.boostable = 1;
+ goto no_change;
+#else
+ next_rip = regs->ip;
+ break;
+#endif
default:
break;
}
diff --git a/arch/x86/kernel/kprobes_64.c b/arch/x86/kernel/kprobes_64.c
index f9cede4..6761a80 100644
--- a/arch/x86/kernel/kprobes_64.c
+++ b/arch/x86/kernel/kprobes_64.c
@@ -16,18 +16,6 @@
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Copyright (C) IBM Corporation, 2002, 2004
- *
- * 2002-Oct Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
- * Probes initial implementation ( includes contributions from
- * Rusty Russell).
- * 2004-July Suparna Bhattacharya <suparna@in.ibm.com> added jumper probes
- * interface to access function arguments.
- * 2004-Oct Jim Keniston <kenistoj@us.ibm.com> and Prasanna S Panchamukhi
- * <prasanna@in.ibm.com> adapted for x86_64
- * 2005-Mar Roland McGrath <roland@redhat.com>
- * Fixed to handle %rip-relative addressing mode correctly.
- * 2005-May Rusty Lynch <rusty.lynch@intel.com>
- * Added function return probes functionality
*/
#include <linux/kprobes.h>
@@ -356,7 +344,11 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p)
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
mutex_lock(&kprobe_mutex);
+#ifdef CONFIG_X86_32
+ free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1));
+#else
free_insn_slot(p->ainsn.insn, 0);
+#endif
mutex_unlock(&kprobe_mutex);
}
@@ -429,6 +421,10 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
*sara = (unsigned long) &kretprobe_trampoline;
}
+/*
+ * Interrupts are disabled on entry as trap3 is an interrupt gate and they
+ * remain disabled thorough out this function.
+ */
static int __kprobes kprobe_handler(struct pt_regs *regs)
{
struct kprobe *p;
@@ -485,7 +481,11 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
* another cpu right after we hit, no further
* handling of this interrupt is appropriate
*/
+#ifdef CONFIG_X86_32
+ regs->ip -= sizeof(kprobe_opcode_t);
+#else
regs->ip = (unsigned long)addr;
+#endif
ret = 1;
goto no_kprobe;
}
@@ -509,7 +509,11 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
* Back up over the (now missing) int3 and run
* the original instruction.
*/
+#ifdef CONFIG_X86_32
+ regs->ip -= sizeof(kprobe_opcode_t);
+#else
regs->ip = (unsigned long)addr;
+#endif
ret = 1;
}
/* Not one of ours: let kernel handle it */
@@ -524,6 +528,15 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
return 1;
ss_probe:
+#if defined(CONFIG_X86_32) && (!defined(CONFIG_PREEMPT) || defined(CONFIG_PM))
+ if (p->ainsn.boostable == 1 && !p->post_handler){
+ /* Boost up -- we can execute copied instructions directly */
+ reset_current_kprobe();
+ regs->ip = (unsigned long)p->ainsn.insn;
+ preempt_enable_no_resched();
+ return 1;
+ }
+#endif
prepare_singlestep(p, regs);
kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
@@ -584,7 +597,11 @@ void kretprobe_trampoline_holder(void)
/*
* Called when we hit the probe point at kretprobe_trampoline
*/
+#ifdef CONFIG_X86_32
+void *__kprobes trampoline_handler(struct pt_regs *regs)
+#else
int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
+#endif
{
struct kretprobe_instance *ri = NULL;
struct hlist_head *head, empty_rp;
@@ -595,7 +612,12 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
INIT_HLIST_HEAD(&empty_rp);
spin_lock_irqsave(&kretprobe_lock, flags);
head = kretprobe_inst_table_head(current);
-
+#ifdef CONFIG_X86_32
+ /* fixup registers */
+ regs->cs = __KERNEL_CS | get_kernel_rpl();
+ regs->ip = trampoline_address;
+ regs->orig_ax = 0xffffffff;
+#endif
/*
* It is possible to have multiple instances associated with a given
* task either because an multiple functions in the call path
@@ -613,10 +635,17 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
if (ri->task != current)
/* another task is sharing our hash bucket */
continue;
-
+#ifdef CONFIG_X86_32
+ if (ri->rp && ri->rp->handler) {
+ __get_cpu_var(current_kprobe) = &ri->rp->kp;
+ get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
+ ri->rp->handler(ri, regs);
+ __get_cpu_var(current_kprobe) = NULL;
+ }
+#else
if (ri->rp && ri->rp->handler)
ri->rp->handler(ri, regs);
-
+#endif
orig_ret_address = (unsigned long)ri->ret_addr;
recycle_rp_inst(ri, &empty_rp);
@@ -630,22 +659,29 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
}
kretprobe_assert(ri, orig_ret_address, trampoline_address);
+#ifdef CONFIG_X86_64
regs->ip = orig_ret_address;
-
reset_current_kprobe();
+#endif
spin_unlock_irqrestore(&kretprobe_lock, flags);
+#ifdef CONFIG_X86_64
preempt_enable_no_resched();
-
+#endif
hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
kfree(ri);
}
+
+#ifdef CONFIG_X86_32
+ return (void*)orig_ret_address;
+#else
/*
* 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;
+#endif
}
/*
@@ -669,6 +705,8 @@ int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
* 2) If the single-stepped instruction was a call, the return address
* that is atop the stack is the address following the copied instruction.
* We need to make it the address following the original instruction.
+ *
+ * This function also checks instruction size for preparing direct execution.
*/
static void __kprobes resume_execution(struct kprobe *p,
struct pt_regs *regs, struct kprobe_ctlblk *kcb)
@@ -691,16 +729,44 @@ static void __kprobes resume_execution(struct kprobe *p,
*tos &= ~(TF_MASK | IF_MASK);
*tos |= kcb->kprobe_old_flags;
break;
- case 0xc3: /* ret/lret */
- case 0xcb:
- case 0xc2:
+ case 0xc2: /* ret/lret */
+ case 0xc3:
case 0xca:
+ case 0xcb:
+#ifdef CONFIG_X86_32
+ case 0xcf: /* iret */
+ /* ip is already adjusted, no more changes required */
+ p->ainsn.boostable = 1;
+ goto no_change;
+#else
/* ip is already adjusted, no more changes required*/
return;
+#endif
case 0xe8: /* call relative - Fix return addr */
*tos = orig_ip + (*tos - copy_ip);
break;
+#ifdef CONFIG_X86_32
+ case 0x9a: /* call absolute -- same as call absolute, indirect */
+ *tos = orig_ip + (*tos - copy_ip);
+ goto no_change;
+#endif
case 0xff:
+#ifdef CONFIG_X86_32
+ if ((insn[1] & 0x30) == 0x10) {
+ /*
+ * call absolute, indirect
+ * Fix return addr; ip is correct.
+ * But this is not boostable
+ */
+ *tos = orig_ip + (*tos - copy_ip);
+ goto no_change;
+ } else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
+ ((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
+ /* ip is correct. And this is boostable */
+ p->ainsn.boostable = 1;
+ goto no_change;
+ }
+#else
if ((insn[1] & 0x30) == 0x10) {
/* call absolute, indirect */
/* Fix return addr; ip is correct. */
@@ -711,10 +777,17 @@ static void __kprobes resume_execution(struct kprobe *p,
/* ip is correct. */
next_rip = regs->ip;
}
+#endif
break;
case 0xea: /* jmp absolute -- ip is correct */
+#ifdef CONFIG_X86_32
+ /* ip is already adjusted, no more changes required */
+ p->ainsn.boostable = 1;
+ goto no_change;
+#else
next_rip = regs->ip;
break;
+#endif
default:
break;
}
@@ -748,6 +821,10 @@ no_change:
restore_btf();
}
+/*
+ * Interrupts are disabled on entry as trap1 is an interrupt gate and they
+ * remain disabled thoroughout this function.
+ */
static int __kprobes post_kprobe_handler(struct pt_regs *regs)
{
struct kprobe *cur = kprobe_running();
@@ -904,6 +981,7 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
kcb->jprobe_saved_regs = *regs;
kcb->jprobe_saved_sp = ®s->sp;
addr = (unsigned long)(kcb->jprobe_saved_sp);
+
/*
* As Linus pointed out, gcc assumes that the callee
* owns the argument space and could overwrite it, e.g.
--
1.5.4.rc0.1083.gf568
>From e7fd0efa2e7860012d0a625c1fda3174ae200dc5 Mon Sep 17 00:00:00 2001
From: Harvey Harrison <harvey.harrison@gmail.com>
Date: Sat, 15 Dec 2007 00:36:37 -0800
Subject: [PATCH] x86: Final kprobes_{32|64}.c unification
Sure, it's ugly, but it can only get better from here.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
---
arch/x86/kernel/kprobes_32.c | 33 +++++++++++++++++++++++++++++++++
arch/x86/kernel/kprobes_64.c | 18 ++++++++++++++++++
2 files changed, 51 insertions(+), 0 deletions(-)
diff --git a/arch/x86/kernel/kprobes_32.c b/arch/x86/kernel/kprobes_32.c
index cb836ce..f195348 100644
--- a/arch/x86/kernel/kprobes_32.c
+++ b/arch/x86/kernel/kprobes_32.c
@@ -20,10 +20,15 @@
#include <linux/kprobes.h>
#include <linux/ptrace.h>
+#include <linux/string.h>
+#include <linux/slab.h>
#include <linux/preempt.h>
+#include <linux/module.h>
#include <linux/kdebug.h>
+
#include <asm/cacheflush.h>
#include <asm/desc.h>
+#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/alternative.h>
@@ -447,6 +452,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
regs->flags &= ~TF_MASK;
regs->flags |= kcb->kprobe_saved_flags;
goto no_kprobe;
+#ifdef CONFIG_X86_32
}
/* We have reentered the kprobe_handler(), since
* another probe was hit while within the handler.
@@ -460,6 +466,33 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
prepare_singlestep(p, regs);
kcb->kprobe_status = KPROBE_REENTER;
return 1;
+#else
+ } else if (kcb->kprobe_status == KPROBE_HIT_SSDONE) {
+ /* TODO: Provide re-entrancy from
+ * post_kprobes_handler() and avoid exception
+ * stack corruption while single-stepping on
+ * the instruction of the new probe.
+ */
+ arch_disarm_kprobe(p);
+ regs->ip = (unsigned long)p->addr;
+ reset_current_kprobe();
+ ret = 1;
+ } else {
+ /* We have reentered the kprobe_handler(), since
+ * another probe was hit while within the
+ * handler. We here save the original kprobe
+ * variables and just single step on 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;
+ }
+#endif
} else {
if (*addr != BREAKPOINT_INSTRUCTION) {
/* The breakpoint instruction was removed by
diff --git a/arch/x86/kernel/kprobes_64.c b/arch/x86/kernel/kprobes_64.c
index 6761a80..f195348 100644
--- a/arch/x86/kernel/kprobes_64.c
+++ b/arch/x86/kernel/kprobes_64.c
@@ -26,6 +26,8 @@
#include <linux/module.h>
#include <linux/kdebug.h>
+#include <asm/cacheflush.h>
+#include <asm/desc.h>
#include <asm/pgtable.h>
#include <asm/uaccess.h>
#include <asm/alternative.h>
@@ -450,6 +452,21 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
regs->flags &= ~TF_MASK;
regs->flags |= kcb->kprobe_saved_flags;
goto no_kprobe;
+#ifdef CONFIG_X86_32
+ }
+ /* 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
} else if (kcb->kprobe_status == KPROBE_HIT_SSDONE) {
/* TODO: Provide re-entrancy from
* post_kprobes_handler() and avoid exception
@@ -475,6 +492,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
kcb->kprobe_status = KPROBE_REENTER;
return 1;
}
+#endif
} else {
if (*addr != BREAKPOINT_INSTRUCTION) {
/* The breakpoint instruction was removed by
--
1.5.4.rc0.1083.gf568
>From 7fe6bd404ae0c51ec0bd334ca28a1f17f247a099 Mon Sep 17 00:00:00 2001
From: Harvey Harrison <harvey.harrison@gmail.com>
Date: Sat, 15 Dec 2007 00:39:44 -0800
Subject: [PATCH] x86: Eliminate kprobes_{32|64}.c
Now that the files are the same, unify the makefiles and
eliminate the duplicates.
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
---
arch/x86/kernel/Makefile_32 | 2 +-
arch/x86/kernel/Makefile_64 | 2 +-
arch/x86/kernel/kprobes.c | 1090 ++++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/kprobes_32.c | 1090 ------------------------------------------
arch/x86/kernel/kprobes_64.c | 1090 ------------------------------------------
5 files changed, 1092 insertions(+), 2182 deletions(-)
diff --git a/arch/x86/kernel/Makefile_32 b/arch/x86/kernel/Makefile_32
index db8cada..62a8120 100644
--- a/arch/x86/kernel/Makefile_32
+++ b/arch/x86/kernel/Makefile_32
@@ -35,7 +35,7 @@ obj-$(CONFIG_KEXEC) += machine_kexec_32.o relocate_kernel_32.o crash.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump_32.o
obj-$(CONFIG_X86_NUMAQ) += numaq_32.o
obj-$(CONFIG_X86_SUMMIT_NUMA) += summit_32.o
-obj-$(CONFIG_KPROBES) += kprobes_32.o
+obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_MODULES) += module_32.o
obj-$(CONFIG_ACPI_SRAT) += srat_32.o
obj-$(CONFIG_EFI) += efi.o efi_32.o efi_stub_32.o
diff --git a/arch/x86/kernel/Makefile_64 b/arch/x86/kernel/Makefile_64
index a961f5c..79e335c 100644
--- a/arch/x86/kernel/Makefile_64
+++ b/arch/x86/kernel/Makefile_64
@@ -34,7 +34,7 @@ obj-$(CONFIG_EARLY_PRINTK) += early_printk.o
obj-$(CONFIG_GART_IOMMU) += pci-gart_64.o aperture_64.o
obj-$(CONFIG_CALGARY_IOMMU) += pci-calgary_64.o tce_64.o
obj-$(CONFIG_SWIOTLB) += pci-swiotlb_64.o
-obj-$(CONFIG_KPROBES) += kprobes_64.o
+obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_X86_PM_TIMER) += pmtimer_64.o
obj-$(CONFIG_X86_VSMP) += vsmp_64.o
obj-$(CONFIG_K8_NB) += k8.o
diff --git a/arch/x86/kernel/kprobes.c b/arch/x86/kernel/kprobes.c
new file mode 100644
index 0000000..f195348
--- /dev/null
+++ b/arch/x86/kernel/kprobes.c
@@ -0,0 +1,1090 @@
+/*
+ * 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, 2004
+ */
+
+#include <linux/kprobes.h>
+#include <linux/ptrace.h>
+#include <linux/string.h>
+#include <linux/slab.h>
+#include <linux/preempt.h>
+#include <linux/module.h>
+#include <linux/kdebug.h>
+
+#include <asm/cacheflush.h>
+#include <asm/desc.h>
+#include <asm/pgtable.h>
+#include <asm/uaccess.h>
+#include <asm/alternative.h>
+
+void jprobe_return_end(void);
+static void __kprobes arch_copy_kprobe(struct kprobe *p);
+
+DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
+DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
+
+struct kretprobe_blackpoint kretprobe_blacklist[] = {
+ {"__switch_to", }, /* This function switches only current task, but
+ doesn't switch kernel stack.*/
+ {NULL, NULL} /* Terminator */
+};
+const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist);
+
+#define W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
+ (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \
+ (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \
+ (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \
+ (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \
+ << (r % sizeof(unsigned long)))
+
+#define R1(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
+ W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) |
+#define R3(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
+ W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) |
+#define R4(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
+ W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf),
+#define RF(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
+ W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)
+
+#ifdef CONFIG_X86_32
+#define R2(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
+ W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf),
+#else
+#define R2(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
+ W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) |
+#endif
+
+/*
+ * Undefined/reserved opcodes, conditional jump, Opcode Extension
+ * Groups, and some special opcodes can not be boost.
+ */
+static const unsigned long
+twobyte_is_boostable[256 / sizeof(unsigned long)] = {
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+ /* ----------------------------------------------- */
+ R1(0x00, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0) /* 00 */
+ R2(0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 10 */
+ R3(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 20 */
+ R4(0x30, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 30 */
+ R1(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 40 */
+ R2(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 50 */
+ R3(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1) /* 60 */
+ R4(0x70, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* 70 */
+ R1(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 80 */
+ R2(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 90 */
+ R3(0xa0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) /* a0 */
+ R4(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) /* b0 */
+ R1(0xc0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) /* c0 */
+ R2(0xd0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) /* d0 */
+ R3(0xe0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) /* e0 */
+ RF(0xf0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0) /* f0 */
+ /* ----------------------------------------------- */
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+};
+
+static const unsigned long
+onebyte_has_modrm[256 / sizeof(unsigned long)] = {
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+ /* ----------------------------------------------- */
+ R1(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 00 */
+ R2(0x10, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 10 */
+ R3(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 20 */
+ R4(0x30, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 30 */
+ R1(0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 40 */
+ R2(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 50 */
+ R3(0x60, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0) /* 60 */
+ R4(0x70, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 70 */
+ R1(0x80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 80 */
+ R2(0x90, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 90 */
+ R3(0xa0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* a0 */
+ R4(0xb0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* b0 */
+ R1(0xc0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) /* c0 */
+ R2(0xd0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) /* d0 */
+ R3(0xe0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* e0 */
+ RF(0xf0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* f0 */
+ /* ----------------------------------------------- */
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+};
+
+static const unsigned long
+twobyte_has_modrm[256 / sizeof(unsigned long)] = {
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+ /* ----------------------------------------------- */
+ R1(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1) /* 0f */
+ R2(0x10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0) /* 1f */
+ R3(0x20, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1) /* 2f */
+ R4(0x30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 3f */
+ R1(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 4f */
+ R2(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 5f */
+ R3(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 6f */
+ R4(0x70, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1) /* 7f */
+ R1(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 8f */
+ R2(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 9f */
+ R3(0xa0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) /* af */
+ R4(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1) /* bf */
+ R1(0xc0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) /* cf */
+ R2(0xd0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* df */
+ R3(0xe0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* ef */
+ RF(0xf0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0) /* ff */
+ /* ----------------------------------------------- */
+ /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
+};
+
+#undef W
+#undef R1
+#undef R2
+#undef R3
+#undef R4
+#undef RF
+
+/* insert a jmp code */
+static inline void set_jmp_op(void *from, void *to)
+{
+ struct __arch_jmp_op {
+ char op;
+ long raddr;
+ } __attribute__((packed)) *jop;
+ jop = (struct __arch_jmp_op *)from;
+ jop->raddr = (long)(to) - ((long)(from) + 5);
+ jop->op = RELATIVEJUMP_INSTRUCTION;
+}
+
+/*
+ * returns non-zero if opcodes can be boosted.
+ */
+static inline int can_boost(kprobe_opcode_t *opcodes)
+{
+ kprobe_opcode_t opcode;
+ kprobe_opcode_t *orig_opcodes = opcodes;
+retry:
+ if (opcodes - orig_opcodes > MAX_INSN_SIZE)
+ return 0;
+ opcode = *(opcodes++);
+
+ /* 2nd-byte opcode */
+ if (opcode == 0x0f) {
+ if (opcodes - orig_opcodes > MAX_INSN_SIZE)
+ return 0;
+ return test_bit(*opcodes, twobyte_is_boostable);
+ }
+
+ switch (opcode & 0xf0) {
+ case 0x60:
+ if (0x63 < opcode && opcode < 0x67)
+ goto retry; /* prefixes */
+ /* can't boost Address-size override and bound */
+ return (opcode != 0x62 && opcode != 0x67);
+ case 0x70:
+ return 0; /* can't boost conditional jump */
+ case 0xc0:
+ /* can't boost software-interruptions */
+ return (0xc1 < opcode && opcode < 0xcc) || opcode == 0xcf;
+ case 0xd0:
+ /* can boost AA* and XLAT */
+ return (opcode == 0xd4 || opcode == 0xd5 || opcode == 0xd7);
+ case 0xe0:
+ /* can boost in/out and absolute jmps */
+ return ((opcode & 0x04) || opcode == 0xea);
+ case 0xf0:
+ if ((opcode & 0x0c) == 0 && opcode != 0xf1)
+ goto retry; /* lock/rep(ne) prefix */
+ /* clear and set flags can be boost */
+ return (opcode == 0xf5 || (0xf7 < opcode && opcode < 0xfe));
+ default:
+ if (opcode == 0x26 || opcode == 0x36 || opcode == 0x3e)
+ goto retry; /* prefixes */
+ /* can't boost CS override and call */
+ return (opcode != 0x2e && opcode != 0x9a);
+ }
+}
+
+/*
+ * returns non-zero if opcode modifies the interrupt flag.
+ */
+static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
+{
+ switch (*insn) {
+ case 0xfa: /* cli */
+ case 0xfb: /* sti */
+ case 0xcf: /* iret/iretd */
+ case 0x9d: /* popf/popfd */
+ return 1;
+ }
+
+#ifdef CONFIG_X86_64
+ /* REX prefix */
+ if (*insn >= 0x40 && *insn <= 0x4f && *++insn == 0xcf)
+ return 1;
+#endif
+ return 0;
+}
+
+int __kprobes arch_prepare_kprobe(struct kprobe *p)
+{
+ /* insn: must be on special executable page on x86_32|64. */
+ p->ainsn.insn = get_insn_slot();
+ if (!p->ainsn.insn)
+ return -ENOMEM;
+
+ arch_copy_kprobe(p);
+ return 0;
+}
+
+/*
+ * Determine if the instruction uses the %rip-relative addressing mode.
+ * If it does, return the address of the 32-bit displacement word.
+ * If not, return null.
+ */
+static s32 __kprobes *is_riprel(u8 *insn)
+{
+ int need_modrm;
+
+ /* Skip legacy instruction prefixes. */
+ while (1) {
+ switch (*insn) {
+ case 0x66:
+ case 0x67:
+ case 0x2e:
+ case 0x3e:
+ case 0x26:
+ case 0x64:
+ case 0x65:
+ case 0x36:
+ case 0xf0:
+ case 0xf3:
+ case 0xf2:
+ ++insn;
+ continue;
+ }
+ break;
+ }
+
+ /* Skip REX instruction prefix. */
+ if ((*insn & 0xf0) == 0x40)
+ ++insn;
+
+ if (*insn == 0x0f) { /* Two-byte opcode. */
+ ++insn;
+ need_modrm = test_bit(*insn, twobyte_has_modrm);
+ } else { /* One-byte opcode. */
+ need_modrm = test_bit(*insn, onebyte_has_modrm);
+ }
+
+ if (need_modrm) {
+ u8 modrm = *++insn;
+ if ((modrm & 0xc7) == 0x05) { /* %rip+disp32 addressing mode */
+ /* Displacement follows ModRM byte. */
+ return (s32 *) ++insn;
+ }
+ }
+
+ /* No %rip-relative addressing mode here. */
+ return NULL;
+}
+
+static void __kprobes arch_copy_kprobe(struct kprobe *p)
+{
+#ifdef CONFIG_X86_32
+ memcpy(p->ainsn.insn, p->addr, (MAX_INSN_SIZE + 1) * sizeof(kprobe_opcode_t));
+ p->opcode = *p->addr;
+ if (can_boost(p->addr)) {
+ p->ainsn.boostable = 0;
+ } else {
+ p->ainsn.boostable = -1;
+ }
+#else
+ s32 *ripdisp;
+ memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE);
+ ripdisp = is_riprel(p->ainsn.insn);
+ if (ripdisp) {
+ /*
+ * The copied instruction uses the %rip-relative
+ * addressing mode. Adjust the displacement for the
+ * difference between the original location of this
+ * instruction and the location of the copy that will
+ * actually be run. The tricky bit here is making sure
+ * that the sign extension happens correctly in this
+ * calculation, since we need a signed 32-bit result to
+ * be sign-extended to 64 bits when it's added to the
+ * %rip value and yield the same 64-bit result that the
+ * sign-extension of the original signed 32-bit
+ * displacement would have given.
+ */
+ s64 disp = (u8 *) p->addr + *ripdisp - (u8 *) p->ainsn.insn;
+ BUG_ON((s64) (s32) disp != disp); /* Sanity check. */
+ *ripdisp = disp;
+ }
+ p->opcode = *p->addr;
+#endif
+}
+
+void __kprobes arch_arm_kprobe(struct kprobe *p)
+{
+ text_poke(p->addr, ((unsigned char []){BREAKPOINT_INSTRUCTION}), 1);
+}
+
+void __kprobes arch_disarm_kprobe(struct kprobe *p)
+{
+ text_poke(p->addr, &p->opcode, 1);
+}
+
+void __kprobes arch_remove_kprobe(struct kprobe *p)
+{
+ mutex_lock(&kprobe_mutex);
+#ifdef CONFIG_X86_32
+ free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1));
+#else
+ free_insn_slot(p->ainsn.insn, 0);
+#endif
+ mutex_unlock(&kprobe_mutex);
+}
+
+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.old_flags = kcb->kprobe_old_flags;
+ kcb->prev_kprobe.saved_flags = kcb->kprobe_saved_flags;
+}
+
+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_old_flags = kcb->prev_kprobe.old_flags;
+ kcb->kprobe_saved_flags = kcb->prev_kprobe.saved_flags;
+}
+
+static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
+ struct kprobe_ctlblk *kcb)
+{
+ __get_cpu_var(current_kprobe) = p;
+ kcb->kprobe_saved_flags = kcb->kprobe_old_flags
+ = (regs->flags & (TF_MASK | IF_MASK));
+ if (is_IF_modifier(p->ainsn.insn))
+ kcb->kprobe_saved_flags &= ~IF_MASK;
+}
+
+static __always_inline void clear_btf(void)
+{
+ if (test_thread_flag(TIF_DEBUGCTLMSR))
+#ifdef CONFIG_X86_32
+ wrmsr(MSR_IA32_DEBUGCTLMSR, 0, 0);
+#else
+ wrmsrl(MSR_IA32_DEBUGCTLMSR, 0);
+#endif
+}
+
+static __always_inline void restore_btf(void)
+{
+ if (test_thread_flag(TIF_DEBUGCTLMSR))
+#ifdef CONFIG_X86_32
+ wrmsr(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr, 0);
+#else
+ wrmsrl(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr);
+#endif
+}
+
+static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
+{
+ clear_btf();
+ regs->flags |= TF_MASK;
+ regs->flags &= ~IF_MASK;
+ /*single step inline if the instruction is an int3*/
+ if (p->opcode == BREAKPOINT_INSTRUCTION)
+ regs->ip = (unsigned long)p->addr;
+ else
+ regs->ip = (unsigned long)p->ainsn.insn;
+}
+
+/* Called with kretprobe_lock held */
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
+ struct pt_regs *regs)
+{
+ unsigned long *sara = ®s->sp;
+
+ ri->ret_addr = (kprobe_opcode_t *) *sara;
+ /* Replace the return addr with trampoline addr */
+ *sara = (unsigned long) &kretprobe_trampoline;
+}
+
+/*
+ * Interrupts are disabled on entry as trap3 is an interrupt gate and they
+ * remain disabled thorough out this function.
+ */
+static int __kprobes kprobe_handler(struct pt_regs *regs)
+{
+ struct kprobe *p;
+ int ret = 0;
+ kprobe_opcode_t *addr;
+ struct kprobe_ctlblk *kcb;
+
+ addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t));
+
+ /*
+ * 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->flags &= ~TF_MASK;
+ regs->flags |= kcb->kprobe_saved_flags;
+ goto no_kprobe;
+#ifdef CONFIG_X86_32
+ }
+ /* 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
+ } else if (kcb->kprobe_status == KPROBE_HIT_SSDONE) {
+ /* TODO: Provide re-entrancy from
+ * post_kprobes_handler() and avoid exception
+ * stack corruption while single-stepping on
+ * the instruction of the new probe.
+ */
+ arch_disarm_kprobe(p);
+ regs->ip = (unsigned long)p->addr;
+ reset_current_kprobe();
+ ret = 1;
+ } else {
+ /* We have reentered the kprobe_handler(), since
+ * another probe was hit while within the
+ * handler. We here save the original kprobe
+ * variables and just single step on 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;
+ }
+#endif
+ } else {
+ if (*addr != BREAKPOINT_INSTRUCTION) {
+ /* The breakpoint instruction was removed by
+ * another cpu right after we hit, no further
+ * handling of this interrupt is appropriate
+ */
+#ifdef CONFIG_X86_32
+ regs->ip -= sizeof(kprobe_opcode_t);
+#else
+ regs->ip = (unsigned long)addr;
+#endif
+ ret = 1;
+ goto no_kprobe;
+ }
+ 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) {
+ if (*addr != BREAKPOINT_INSTRUCTION) {
+ /*
+ * The breakpoint instruction was removed right
+ * after we hit it. Another cpu has removed
+ * either a probepoint or a debugger breakpoint
+ * at this address. In either case, no further
+ * handling of this interrupt is appropriate.
+ * Back up over the (now missing) int3 and run
+ * the original instruction.
+ */
+#ifdef CONFIG_X86_32
+ regs->ip -= sizeof(kprobe_opcode_t);
+#else
+ regs->ip = (unsigned long)addr;
+#endif
+ ret = 1;
+ }
+ /* Not one of ours: let kernel handle it */
+ goto no_kprobe;
+ }
+
+ set_current_kprobe(p, regs, kcb);
+ kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+
+ if (p->pre_handler && p->pre_handler(p, regs))
+ /* handler has already set things up, so skip ss setup */
+ return 1;
+
+ss_probe:
+#if defined(CONFIG_X86_32) && (!defined(CONFIG_PREEMPT) || defined(CONFIG_PM))
+ if (p->ainsn.boostable == 1 && !p->post_handler){
+ /* Boost up -- we can execute copied instructions directly */
+ reset_current_kprobe();
+ regs->ip = (unsigned long)p->ainsn.insn;
+ preempt_enable_no_resched();
+ return 1;
+ }
+#endif
+ prepare_singlestep(p, regs);
+ kcb->kprobe_status = KPROBE_HIT_SS;
+ return 1;
+
+no_kprobe:
+ preempt_enable_no_resched();
+ return ret;
+}
+
+/*
+ * For function-return probes, init_kprobes() establishes a probepoint
+ * here. When a retprobed function returns, this probe is hit and
+ * trampoline_probe_handler() runs, calling the kretprobe's handler.
+ */
+void kretprobe_trampoline_holder(void)
+{
+#ifdef CONFIG_X86_32
+ asm volatile ( ".global kretprobe_trampoline\n"
+ "kretprobe_trampoline: \n"
+ " pushf\n"
+ /* skip cs, ip, orig_ax */
+ " subl $12, %esp\n"
+ " pushl %fs\n"
+ " pushl %ds\n"
+ " pushl %es\n"
+ " pushl %eax\n"
+ " pushl %ebp\n"
+ " pushl %edi\n"
+ " pushl %esi\n"
+ " pushl %edx\n"
+ " pushl %ecx\n"
+ " pushl %ebx\n"
+ " movl %esp, %eax\n"
+ " call trampoline_handler\n"
+ /* move flags to cs */
+ " movl 52(%esp), %edx\n"
+ " movl %edx, 48(%esp)\n"
+ /* save true return address on flags */
+ " movl %eax, 52(%esp)\n"
+ " popl %ebx\n"
+ " popl %ecx\n"
+ " popl %edx\n"
+ " popl %esi\n"
+ " popl %edi\n"
+ " popl %ebp\n"
+ " popl %eax\n"
+ /* skip ip, orig_ax, es, ds, fs */
+ " addl $20, %esp\n"
+ " popf\n"
+ " ret\n");
+#else
+ asm volatile ( ".global kretprobe_trampoline\n"
+ "kretprobe_trampoline: \n"
+ "nop\n");
+#endif
+}
+
+/*
+ * Called when we hit the probe point at kretprobe_trampoline
+ */
+#ifdef CONFIG_X86_32
+void *__kprobes trampoline_handler(struct pt_regs *regs)
+#else
+int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
+#endif
+{
+ 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);
+#ifdef CONFIG_X86_32
+ /* fixup registers */
+ regs->cs = __KERNEL_CS | get_kernel_rpl();
+ regs->ip = trampoline_address;
+ regs->orig_ax = 0xffffffff;
+#endif
+ /*
+ * 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;
+#ifdef CONFIG_X86_32
+ if (ri->rp && ri->rp->handler) {
+ __get_cpu_var(current_kprobe) = &ri->rp->kp;
+ get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
+ ri->rp->handler(ri, regs);
+ __get_cpu_var(current_kprobe) = NULL;
+ }
+#else
+ if (ri->rp && ri->rp->handler)
+ ri->rp->handler(ri, regs);
+#endif
+ 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);
+#ifdef CONFIG_X86_64
+ regs->ip = orig_ret_address;
+ reset_current_kprobe();
+#endif
+ spin_unlock_irqrestore(&kretprobe_lock, flags);
+#ifdef CONFIG_X86_64
+ preempt_enable_no_resched();
+#endif
+ hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
+ hlist_del(&ri->hlist);
+ kfree(ri);
+ }
+
+#ifdef CONFIG_X86_32
+ return (void*)orig_ret_address;
+#else
+ /*
+ * 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;
+#endif
+}
+
+/*
+ * Called after single-stepping. p->addr is the address of the
+ * instruction whose first byte has been replaced by the "int 3"
+ * 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.
+ *
+ * This function prepares to return from the post-single-step
+ * interrupt. We have to fix up the stack as follows:
+ *
+ * 0) Except in the case of absolute or indirect jump or call instructions,
+ * the new ip is relative to the copied instruction. We need to make
+ * it relative to the original instruction.
+ *
+ * 1) If the single-stepped instruction was pushfl, then the TF and IF
+ * flags are set in the just-pushed flags, and may need to be cleared.
+ *
+ * 2) If the single-stepped instruction was a call, the return address
+ * that is atop the stack is the address following the copied instruction.
+ * We need to make it the address following the original instruction.
+ *
+ * This function also checks instruction size for preparing direct execution.
+ */
+static void __kprobes resume_execution(struct kprobe *p,
+ struct pt_regs *regs, struct kprobe_ctlblk *kcb)
+{
+ unsigned long *tos = ®s->sp;
+ unsigned long next_rip = 0;
+ unsigned long copy_ip = (unsigned long)p->ainsn.insn;
+ unsigned long orig_ip = (unsigned long)p->addr;
+ kprobe_opcode_t *insn = p->ainsn.insn;
+
+#ifdef CONFIG_X86_64
+ /*skip the REX prefix*/
+ if (*insn >= 0x40 && *insn <= 0x4f)
+ insn++;
+#endif
+
+ regs->flags &= ~TF_MASK;
+ switch (*insn) {
+ case 0x9c: /* pushfl */
+ *tos &= ~(TF_MASK | IF_MASK);
+ *tos |= kcb->kprobe_old_flags;
+ break;
+ case 0xc2: /* ret/lret */
+ case 0xc3:
+ case 0xca:
+ case 0xcb:
+#ifdef CONFIG_X86_32
+ case 0xcf: /* iret */
+ /* ip is already adjusted, no more changes required */
+ p->ainsn.boostable = 1;
+ goto no_change;
+#else
+ /* ip is already adjusted, no more changes required*/
+ return;
+#endif
+ case 0xe8: /* call relative - Fix return addr */
+ *tos = orig_ip + (*tos - copy_ip);
+ break;
+#ifdef CONFIG_X86_32
+ case 0x9a: /* call absolute -- same as call absolute, indirect */
+ *tos = orig_ip + (*tos - copy_ip);
+ goto no_change;
+#endif
+ case 0xff:
+#ifdef CONFIG_X86_32
+ if ((insn[1] & 0x30) == 0x10) {
+ /*
+ * call absolute, indirect
+ * Fix return addr; ip is correct.
+ * But this is not boostable
+ */
+ *tos = orig_ip + (*tos - copy_ip);
+ goto no_change;
+ } else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
+ ((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
+ /* ip is correct. And this is boostable */
+ p->ainsn.boostable = 1;
+ goto no_change;
+ }
+#else
+ if ((insn[1] & 0x30) == 0x10) {
+ /* call absolute, indirect */
+ /* Fix return addr; ip is correct. */
+ next_rip = regs->ip;
+ *tos = orig_ip + (*tos - copy_ip);
+ } else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
+ ((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
+ /* ip is correct. */
+ next_rip = regs->ip;
+ }
+#endif
+ break;
+ case 0xea: /* jmp absolute -- ip is correct */
+#ifdef CONFIG_X86_32
+ /* ip is already adjusted, no more changes required */
+ p->ainsn.boostable = 1;
+ goto no_change;
+#else
+ next_rip = regs->ip;
+ break;
+#endif
+ default:
+ break;
+ }
+
+#ifdef CONFIG_X86_32
+ if (p->ainsn.boostable == 0) {
+ if ((regs->ip > copy_ip) &&
+ (regs->ip - copy_ip) + 5 < (MAX_INSN_SIZE + 1)) {
+ /*
+ * These instructions can be executed directly if it
+ * jumps back to correct address.
+ */
+ set_jmp_op((void *)regs->ip,
+ (void *)orig_ip + (regs->ip - copy_ip));
+ p->ainsn.boostable = 1;
+ } else {
+ p->ainsn.boostable = -1;
+ }
+ }
+
+ regs->ip = orig_ip + (regs->ip - copy_ip);
+
+no_change:
+#else
+ if (next_rip) {
+ regs->ip = next_rip;
+ } else {
+ regs->ip = orig_ip + (regs->ip - copy_ip);
+ }
+#endif
+ restore_btf();
+}
+
+/*
+ * Interrupts are disabled on entry as trap1 is an interrupt gate and they
+ * remain disabled thoroughout this function.
+ */
+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, kcb);
+ regs->flags |= kcb->kprobe_saved_flags;
+ trace_hardirqs_fixup_flags(regs->flags);
+
+ /* Restore 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, flags
+ * will have TF set, in which case, continue the remaining processing
+ * of do_debug, as if this is not a probe hit.
+ */
+ if (regs->flags & TF_MASK)
+ 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();
+#ifdef CONFIG_X86_64
+ const struct exception_table_entry *fixup;
+#endif
+
+ switch(kcb->kprobe_status) {
+ 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 ip points back to the probe address
+ * and allow the page fault handler to continue as a
+ * normal page fault.
+ */
+ regs->ip = (unsigned long)cur->addr;
+ regs->flags |= kcb->kprobe_old_flags;
+ 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.
+ */
+#ifdef CONFIG_X86_32
+ if (fixup_exception(regs))
+ return 1;
+#else
+ fixup = search_exception_tables(regs->ip);
+ if (fixup) {
+ regs->ip = fixup->fixup;
+ return 1;
+ }
+#endif
+ /*
+ * Exception couldn't be fixed up,
+ * Let do_page_fault() fix it.
+ */
+ break;
+ default:
+ break;
+ }
+ return 0;
+}
+
+/*
+ * Wrapper routine 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;
+
+#ifdef CONFIG_X86_32
+ if (args->regs && user_mode_vm(args->regs))
+ return ret;
+#else
+ if (args->regs && user_mode(args->regs))
+ return ret;
+#endif
+
+ switch (val) {
+ case DIE_INT3:
+ if (kprobe_handler(args->regs))
+ ret = NOTIFY_STOP;
+ break;
+ case DIE_DEBUG:
+ if (post_kprobe_handler(args->regs))
+ ret = NOTIFY_STOP;
+ break;
+ case DIE_GPF:
+ /* 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();
+
+ kcb->jprobe_saved_regs = *regs;
+ kcb->jprobe_saved_sp = ®s->sp;
+ addr = (unsigned long)(kcb->jprobe_saved_sp);
+
+ /*
+ * As Linus pointed out, gcc assumes that the callee
+ * owns the argument space and could overwrite it, e.g.
+ * tailcall optimization. So, to be absolutely safe
+ * we also save and restore enough stack bytes to cover
+ * the argument area.
+ */
+ memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr,
+ MIN_STACK_SIZE(addr));
+ regs->flags &= ~IF_MASK;
+ trace_hardirqs_off();
+ regs->ip = (unsigned long)(jp->entry);
+ return 1;
+}
+
+void __kprobes jprobe_return(void)
+{
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+#ifdef CONFIG_X86_32
+ asm volatile (" xchgl %%ebx,%%esp \n"
+ " int3 \n"
+ " .globl jprobe_return_end \n"
+ " jprobe_return_end: \n"
+ " nop \n"::"b"
+ (kcb->jprobe_saved_sp):"memory");
+#else
+ asm volatile (" xchg %%rbx,%%rsp \n"
+ " int3 \n"
+ " .globl jprobe_return_end \n"
+ " jprobe_return_end: \n"
+ " nop \n"::"b"
+ (kcb->jprobe_saved_sp):"memory");
+#endif
+}
+
+int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
+{
+ struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
+ u8 *addr = (u8 *) (regs->ip - 1);
+ unsigned long stack_addr = (unsigned long)(kcb->jprobe_saved_sp);
+ struct jprobe *jp = container_of(p, struct jprobe, kp);
+
+ if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) {
+ if (®s->sp != kcb->jprobe_saved_sp) {
+ struct pt_regs *saved_regs =
+ container_of(kcb->jprobe_saved_sp,
+ struct pt_regs, sp);
+ printk("current sp %p does not match saved sp %p\n",
+ ®s->sp, kcb->jprobe_saved_sp);
+ printk("Saved registers for jprobe %p\n", jp);
+ show_registers(saved_regs);
+ printk("Current registers\n");
+ show_registers(regs);
+ BUG();
+ }
+ *regs = kcb->jprobe_saved_regs;
+ memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack,
+ MIN_STACK_SIZE(stack_addr));
+ preempt_enable_no_resched();
+ return 1;
+ }
+ return 0;
+}
+
+#ifdef CONFIG_X86_64
+static struct kprobe trampoline_p = {
+ .addr = (kprobe_opcode_t *) &kretprobe_trampoline,
+ .pre_handler = trampoline_probe_handler
+};
+#endif
+
+int __kprobes arch_trampoline_kprobe(struct kprobe *p)
+{
+#ifdef CONFIG_X86_64
+ if (p->addr == (kprobe_opcode_t *)&kretprobe_trampoline)
+ return 1;
+#endif
+ return 0;
+}
+
+int __init arch_init_kprobes(void)
+{
+#ifdef CONFIG_X86_32
+ return 0;
+#else
+ return register_kprobe(&trampoline_p);
+#endif
+}
diff --git a/arch/x86/kernel/kprobes_32.c b/arch/x86/kernel/kprobes_32.c
deleted file mode 100644
index f195348..0000000
--- a/arch/x86/kernel/kprobes_32.c
+++ /dev/null
@@ -1,1090 +0,0 @@
-/*
- * 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, 2004
- */
-
-#include <linux/kprobes.h>
-#include <linux/ptrace.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/preempt.h>
-#include <linux/module.h>
-#include <linux/kdebug.h>
-
-#include <asm/cacheflush.h>
-#include <asm/desc.h>
-#include <asm/pgtable.h>
-#include <asm/uaccess.h>
-#include <asm/alternative.h>
-
-void jprobe_return_end(void);
-static void __kprobes arch_copy_kprobe(struct kprobe *p);
-
-DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
-DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
-
-struct kretprobe_blackpoint kretprobe_blacklist[] = {
- {"__switch_to", }, /* This function switches only current task, but
- doesn't switch kernel stack.*/
- {NULL, NULL} /* Terminator */
-};
-const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist);
-
-#define W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \
- (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \
- (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \
- (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \
- << (r % sizeof(unsigned long)))
-
-#define R1(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) |
-#define R3(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) |
-#define R4(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf),
-#define RF(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)
-
-#ifdef CONFIG_X86_32
-#define R2(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf),
-#else
-#define R2(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) |
-#endif
-
-/*
- * Undefined/reserved opcodes, conditional jump, Opcode Extension
- * Groups, and some special opcodes can not be boost.
- */
-static const unsigned long
-twobyte_is_boostable[256 / sizeof(unsigned long)] = {
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
- /* ----------------------------------------------- */
- R1(0x00, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0) /* 00 */
- R2(0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 10 */
- R3(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 20 */
- R4(0x30, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 30 */
- R1(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 40 */
- R2(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 50 */
- R3(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1) /* 60 */
- R4(0x70, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* 70 */
- R1(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 80 */
- R2(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 90 */
- R3(0xa0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) /* a0 */
- R4(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) /* b0 */
- R1(0xc0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) /* c0 */
- R2(0xd0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) /* d0 */
- R3(0xe0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) /* e0 */
- RF(0xf0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0) /* f0 */
- /* ----------------------------------------------- */
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
-};
-
-static const unsigned long
-onebyte_has_modrm[256 / sizeof(unsigned long)] = {
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
- /* ----------------------------------------------- */
- R1(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 00 */
- R2(0x10, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 10 */
- R3(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 20 */
- R4(0x30, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 30 */
- R1(0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 40 */
- R2(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 50 */
- R3(0x60, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0) /* 60 */
- R4(0x70, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 70 */
- R1(0x80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 80 */
- R2(0x90, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 90 */
- R3(0xa0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* a0 */
- R4(0xb0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* b0 */
- R1(0xc0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) /* c0 */
- R2(0xd0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) /* d0 */
- R3(0xe0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* e0 */
- RF(0xf0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* f0 */
- /* ----------------------------------------------- */
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
-};
-
-static const unsigned long
-twobyte_has_modrm[256 / sizeof(unsigned long)] = {
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
- /* ----------------------------------------------- */
- R1(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1) /* 0f */
- R2(0x10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0) /* 1f */
- R3(0x20, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1) /* 2f */
- R4(0x30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 3f */
- R1(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 4f */
- R2(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 5f */
- R3(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 6f */
- R4(0x70, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1) /* 7f */
- R1(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 8f */
- R2(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 9f */
- R3(0xa0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) /* af */
- R4(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1) /* bf */
- R1(0xc0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) /* cf */
- R2(0xd0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* df */
- R3(0xe0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* ef */
- RF(0xf0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0) /* ff */
- /* ----------------------------------------------- */
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
-};
-
-#undef W
-#undef R1
-#undef R2
-#undef R3
-#undef R4
-#undef RF
-
-/* insert a jmp code */
-static inline void set_jmp_op(void *from, void *to)
-{
- struct __arch_jmp_op {
- char op;
- long raddr;
- } __attribute__((packed)) *jop;
- jop = (struct __arch_jmp_op *)from;
- jop->raddr = (long)(to) - ((long)(from) + 5);
- jop->op = RELATIVEJUMP_INSTRUCTION;
-}
-
-/*
- * returns non-zero if opcodes can be boosted.
- */
-static inline int can_boost(kprobe_opcode_t *opcodes)
-{
- kprobe_opcode_t opcode;
- kprobe_opcode_t *orig_opcodes = opcodes;
-retry:
- if (opcodes - orig_opcodes > MAX_INSN_SIZE)
- return 0;
- opcode = *(opcodes++);
-
- /* 2nd-byte opcode */
- if (opcode == 0x0f) {
- if (opcodes - orig_opcodes > MAX_INSN_SIZE)
- return 0;
- return test_bit(*opcodes, twobyte_is_boostable);
- }
-
- switch (opcode & 0xf0) {
- case 0x60:
- if (0x63 < opcode && opcode < 0x67)
- goto retry; /* prefixes */
- /* can't boost Address-size override and bound */
- return (opcode != 0x62 && opcode != 0x67);
- case 0x70:
- return 0; /* can't boost conditional jump */
- case 0xc0:
- /* can't boost software-interruptions */
- return (0xc1 < opcode && opcode < 0xcc) || opcode == 0xcf;
- case 0xd0:
- /* can boost AA* and XLAT */
- return (opcode == 0xd4 || opcode == 0xd5 || opcode == 0xd7);
- case 0xe0:
- /* can boost in/out and absolute jmps */
- return ((opcode & 0x04) || opcode == 0xea);
- case 0xf0:
- if ((opcode & 0x0c) == 0 && opcode != 0xf1)
- goto retry; /* lock/rep(ne) prefix */
- /* clear and set flags can be boost */
- return (opcode == 0xf5 || (0xf7 < opcode && opcode < 0xfe));
- default:
- if (opcode == 0x26 || opcode == 0x36 || opcode == 0x3e)
- goto retry; /* prefixes */
- /* can't boost CS override and call */
- return (opcode != 0x2e && opcode != 0x9a);
- }
-}
-
-/*
- * returns non-zero if opcode modifies the interrupt flag.
- */
-static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
-{
- switch (*insn) {
- case 0xfa: /* cli */
- case 0xfb: /* sti */
- case 0xcf: /* iret/iretd */
- case 0x9d: /* popf/popfd */
- return 1;
- }
-
-#ifdef CONFIG_X86_64
- /* REX prefix */
- if (*insn >= 0x40 && *insn <= 0x4f && *++insn == 0xcf)
- return 1;
-#endif
- return 0;
-}
-
-int __kprobes arch_prepare_kprobe(struct kprobe *p)
-{
- /* insn: must be on special executable page on x86_32|64. */
- p->ainsn.insn = get_insn_slot();
- if (!p->ainsn.insn)
- return -ENOMEM;
-
- arch_copy_kprobe(p);
- return 0;
-}
-
-/*
- * Determine if the instruction uses the %rip-relative addressing mode.
- * If it does, return the address of the 32-bit displacement word.
- * If not, return null.
- */
-static s32 __kprobes *is_riprel(u8 *insn)
-{
- int need_modrm;
-
- /* Skip legacy instruction prefixes. */
- while (1) {
- switch (*insn) {
- case 0x66:
- case 0x67:
- case 0x2e:
- case 0x3e:
- case 0x26:
- case 0x64:
- case 0x65:
- case 0x36:
- case 0xf0:
- case 0xf3:
- case 0xf2:
- ++insn;
- continue;
- }
- break;
- }
-
- /* Skip REX instruction prefix. */
- if ((*insn & 0xf0) == 0x40)
- ++insn;
-
- if (*insn == 0x0f) { /* Two-byte opcode. */
- ++insn;
- need_modrm = test_bit(*insn, twobyte_has_modrm);
- } else { /* One-byte opcode. */
- need_modrm = test_bit(*insn, onebyte_has_modrm);
- }
-
- if (need_modrm) {
- u8 modrm = *++insn;
- if ((modrm & 0xc7) == 0x05) { /* %rip+disp32 addressing mode */
- /* Displacement follows ModRM byte. */
- return (s32 *) ++insn;
- }
- }
-
- /* No %rip-relative addressing mode here. */
- return NULL;
-}
-
-static void __kprobes arch_copy_kprobe(struct kprobe *p)
-{
-#ifdef CONFIG_X86_32
- memcpy(p->ainsn.insn, p->addr, (MAX_INSN_SIZE + 1) * sizeof(kprobe_opcode_t));
- p->opcode = *p->addr;
- if (can_boost(p->addr)) {
- p->ainsn.boostable = 0;
- } else {
- p->ainsn.boostable = -1;
- }
-#else
- s32 *ripdisp;
- memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE);
- ripdisp = is_riprel(p->ainsn.insn);
- if (ripdisp) {
- /*
- * The copied instruction uses the %rip-relative
- * addressing mode. Adjust the displacement for the
- * difference between the original location of this
- * instruction and the location of the copy that will
- * actually be run. The tricky bit here is making sure
- * that the sign extension happens correctly in this
- * calculation, since we need a signed 32-bit result to
- * be sign-extended to 64 bits when it's added to the
- * %rip value and yield the same 64-bit result that the
- * sign-extension of the original signed 32-bit
- * displacement would have given.
- */
- s64 disp = (u8 *) p->addr + *ripdisp - (u8 *) p->ainsn.insn;
- BUG_ON((s64) (s32) disp != disp); /* Sanity check. */
- *ripdisp = disp;
- }
- p->opcode = *p->addr;
-#endif
-}
-
-void __kprobes arch_arm_kprobe(struct kprobe *p)
-{
- text_poke(p->addr, ((unsigned char []){BREAKPOINT_INSTRUCTION}), 1);
-}
-
-void __kprobes arch_disarm_kprobe(struct kprobe *p)
-{
- text_poke(p->addr, &p->opcode, 1);
-}
-
-void __kprobes arch_remove_kprobe(struct kprobe *p)
-{
- mutex_lock(&kprobe_mutex);
-#ifdef CONFIG_X86_32
- free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1));
-#else
- free_insn_slot(p->ainsn.insn, 0);
-#endif
- mutex_unlock(&kprobe_mutex);
-}
-
-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.old_flags = kcb->kprobe_old_flags;
- kcb->prev_kprobe.saved_flags = kcb->kprobe_saved_flags;
-}
-
-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_old_flags = kcb->prev_kprobe.old_flags;
- kcb->kprobe_saved_flags = kcb->prev_kprobe.saved_flags;
-}
-
-static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
-{
- __get_cpu_var(current_kprobe) = p;
- kcb->kprobe_saved_flags = kcb->kprobe_old_flags
- = (regs->flags & (TF_MASK | IF_MASK));
- if (is_IF_modifier(p->ainsn.insn))
- kcb->kprobe_saved_flags &= ~IF_MASK;
-}
-
-static __always_inline void clear_btf(void)
-{
- if (test_thread_flag(TIF_DEBUGCTLMSR))
-#ifdef CONFIG_X86_32
- wrmsr(MSR_IA32_DEBUGCTLMSR, 0, 0);
-#else
- wrmsrl(MSR_IA32_DEBUGCTLMSR, 0);
-#endif
-}
-
-static __always_inline void restore_btf(void)
-{
- if (test_thread_flag(TIF_DEBUGCTLMSR))
-#ifdef CONFIG_X86_32
- wrmsr(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr, 0);
-#else
- wrmsrl(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr);
-#endif
-}
-
-static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
-{
- clear_btf();
- regs->flags |= TF_MASK;
- regs->flags &= ~IF_MASK;
- /*single step inline if the instruction is an int3*/
- if (p->opcode == BREAKPOINT_INSTRUCTION)
- regs->ip = (unsigned long)p->addr;
- else
- regs->ip = (unsigned long)p->ainsn.insn;
-}
-
-/* Called with kretprobe_lock held */
-void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
- struct pt_regs *regs)
-{
- unsigned long *sara = ®s->sp;
-
- ri->ret_addr = (kprobe_opcode_t *) *sara;
- /* Replace the return addr with trampoline addr */
- *sara = (unsigned long) &kretprobe_trampoline;
-}
-
-/*
- * Interrupts are disabled on entry as trap3 is an interrupt gate and they
- * remain disabled thorough out this function.
- */
-static int __kprobes kprobe_handler(struct pt_regs *regs)
-{
- struct kprobe *p;
- int ret = 0;
- kprobe_opcode_t *addr;
- struct kprobe_ctlblk *kcb;
-
- addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t));
-
- /*
- * 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->flags &= ~TF_MASK;
- regs->flags |= kcb->kprobe_saved_flags;
- goto no_kprobe;
-#ifdef CONFIG_X86_32
- }
- /* 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
- } else if (kcb->kprobe_status == KPROBE_HIT_SSDONE) {
- /* TODO: Provide re-entrancy from
- * post_kprobes_handler() and avoid exception
- * stack corruption while single-stepping on
- * the instruction of the new probe.
- */
- arch_disarm_kprobe(p);
- regs->ip = (unsigned long)p->addr;
- reset_current_kprobe();
- ret = 1;
- } else {
- /* We have reentered the kprobe_handler(), since
- * another probe was hit while within the
- * handler. We here save the original kprobe
- * variables and just single step on 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;
- }
-#endif
- } else {
- if (*addr != BREAKPOINT_INSTRUCTION) {
- /* The breakpoint instruction was removed by
- * another cpu right after we hit, no further
- * handling of this interrupt is appropriate
- */
-#ifdef CONFIG_X86_32
- regs->ip -= sizeof(kprobe_opcode_t);
-#else
- regs->ip = (unsigned long)addr;
-#endif
- ret = 1;
- goto no_kprobe;
- }
- 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) {
- if (*addr != BREAKPOINT_INSTRUCTION) {
- /*
- * The breakpoint instruction was removed right
- * after we hit it. Another cpu has removed
- * either a probepoint or a debugger breakpoint
- * at this address. In either case, no further
- * handling of this interrupt is appropriate.
- * Back up over the (now missing) int3 and run
- * the original instruction.
- */
-#ifdef CONFIG_X86_32
- regs->ip -= sizeof(kprobe_opcode_t);
-#else
- regs->ip = (unsigned long)addr;
-#endif
- ret = 1;
- }
- /* Not one of ours: let kernel handle it */
- goto no_kprobe;
- }
-
- set_current_kprobe(p, regs, kcb);
- kcb->kprobe_status = KPROBE_HIT_ACTIVE;
-
- if (p->pre_handler && p->pre_handler(p, regs))
- /* handler has already set things up, so skip ss setup */
- return 1;
-
-ss_probe:
-#if defined(CONFIG_X86_32) && (!defined(CONFIG_PREEMPT) || defined(CONFIG_PM))
- if (p->ainsn.boostable == 1 && !p->post_handler){
- /* Boost up -- we can execute copied instructions directly */
- reset_current_kprobe();
- regs->ip = (unsigned long)p->ainsn.insn;
- preempt_enable_no_resched();
- return 1;
- }
-#endif
- prepare_singlestep(p, regs);
- kcb->kprobe_status = KPROBE_HIT_SS;
- return 1;
-
-no_kprobe:
- preempt_enable_no_resched();
- return ret;
-}
-
-/*
- * For function-return probes, init_kprobes() establishes a probepoint
- * here. When a retprobed function returns, this probe is hit and
- * trampoline_probe_handler() runs, calling the kretprobe's handler.
- */
-void kretprobe_trampoline_holder(void)
-{
-#ifdef CONFIG_X86_32
- asm volatile ( ".global kretprobe_trampoline\n"
- "kretprobe_trampoline: \n"
- " pushf\n"
- /* skip cs, ip, orig_ax */
- " subl $12, %esp\n"
- " pushl %fs\n"
- " pushl %ds\n"
- " pushl %es\n"
- " pushl %eax\n"
- " pushl %ebp\n"
- " pushl %edi\n"
- " pushl %esi\n"
- " pushl %edx\n"
- " pushl %ecx\n"
- " pushl %ebx\n"
- " movl %esp, %eax\n"
- " call trampoline_handler\n"
- /* move flags to cs */
- " movl 52(%esp), %edx\n"
- " movl %edx, 48(%esp)\n"
- /* save true return address on flags */
- " movl %eax, 52(%esp)\n"
- " popl %ebx\n"
- " popl %ecx\n"
- " popl %edx\n"
- " popl %esi\n"
- " popl %edi\n"
- " popl %ebp\n"
- " popl %eax\n"
- /* skip ip, orig_ax, es, ds, fs */
- " addl $20, %esp\n"
- " popf\n"
- " ret\n");
-#else
- asm volatile ( ".global kretprobe_trampoline\n"
- "kretprobe_trampoline: \n"
- "nop\n");
-#endif
-}
-
-/*
- * Called when we hit the probe point at kretprobe_trampoline
- */
-#ifdef CONFIG_X86_32
-void *__kprobes trampoline_handler(struct pt_regs *regs)
-#else
-int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
-#endif
-{
- 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);
-#ifdef CONFIG_X86_32
- /* fixup registers */
- regs->cs = __KERNEL_CS | get_kernel_rpl();
- regs->ip = trampoline_address;
- regs->orig_ax = 0xffffffff;
-#endif
- /*
- * 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;
-#ifdef CONFIG_X86_32
- if (ri->rp && ri->rp->handler) {
- __get_cpu_var(current_kprobe) = &ri->rp->kp;
- get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
- ri->rp->handler(ri, regs);
- __get_cpu_var(current_kprobe) = NULL;
- }
-#else
- if (ri->rp && ri->rp->handler)
- ri->rp->handler(ri, regs);
-#endif
- 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);
-#ifdef CONFIG_X86_64
- regs->ip = orig_ret_address;
- reset_current_kprobe();
-#endif
- spin_unlock_irqrestore(&kretprobe_lock, flags);
-#ifdef CONFIG_X86_64
- preempt_enable_no_resched();
-#endif
- hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
- hlist_del(&ri->hlist);
- kfree(ri);
- }
-
-#ifdef CONFIG_X86_32
- return (void*)orig_ret_address;
-#else
- /*
- * 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;
-#endif
-}
-
-/*
- * Called after single-stepping. p->addr is the address of the
- * instruction whose first byte has been replaced by the "int 3"
- * 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.
- *
- * This function prepares to return from the post-single-step
- * interrupt. We have to fix up the stack as follows:
- *
- * 0) Except in the case of absolute or indirect jump or call instructions,
- * the new ip is relative to the copied instruction. We need to make
- * it relative to the original instruction.
- *
- * 1) If the single-stepped instruction was pushfl, then the TF and IF
- * flags are set in the just-pushed flags, and may need to be cleared.
- *
- * 2) If the single-stepped instruction was a call, the return address
- * that is atop the stack is the address following the copied instruction.
- * We need to make it the address following the original instruction.
- *
- * This function also checks instruction size for preparing direct execution.
- */
-static void __kprobes resume_execution(struct kprobe *p,
- struct pt_regs *regs, struct kprobe_ctlblk *kcb)
-{
- unsigned long *tos = ®s->sp;
- unsigned long next_rip = 0;
- unsigned long copy_ip = (unsigned long)p->ainsn.insn;
- unsigned long orig_ip = (unsigned long)p->addr;
- kprobe_opcode_t *insn = p->ainsn.insn;
-
-#ifdef CONFIG_X86_64
- /*skip the REX prefix*/
- if (*insn >= 0x40 && *insn <= 0x4f)
- insn++;
-#endif
-
- regs->flags &= ~TF_MASK;
- switch (*insn) {
- case 0x9c: /* pushfl */
- *tos &= ~(TF_MASK | IF_MASK);
- *tos |= kcb->kprobe_old_flags;
- break;
- case 0xc2: /* ret/lret */
- case 0xc3:
- case 0xca:
- case 0xcb:
-#ifdef CONFIG_X86_32
- case 0xcf: /* iret */
- /* ip is already adjusted, no more changes required */
- p->ainsn.boostable = 1;
- goto no_change;
-#else
- /* ip is already adjusted, no more changes required*/
- return;
-#endif
- case 0xe8: /* call relative - Fix return addr */
- *tos = orig_ip + (*tos - copy_ip);
- break;
-#ifdef CONFIG_X86_32
- case 0x9a: /* call absolute -- same as call absolute, indirect */
- *tos = orig_ip + (*tos - copy_ip);
- goto no_change;
-#endif
- case 0xff:
-#ifdef CONFIG_X86_32
- if ((insn[1] & 0x30) == 0x10) {
- /*
- * call absolute, indirect
- * Fix return addr; ip is correct.
- * But this is not boostable
- */
- *tos = orig_ip + (*tos - copy_ip);
- goto no_change;
- } else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
- ((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
- /* ip is correct. And this is boostable */
- p->ainsn.boostable = 1;
- goto no_change;
- }
-#else
- if ((insn[1] & 0x30) == 0x10) {
- /* call absolute, indirect */
- /* Fix return addr; ip is correct. */
- next_rip = regs->ip;
- *tos = orig_ip + (*tos - copy_ip);
- } else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
- ((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
- /* ip is correct. */
- next_rip = regs->ip;
- }
-#endif
- break;
- case 0xea: /* jmp absolute -- ip is correct */
-#ifdef CONFIG_X86_32
- /* ip is already adjusted, no more changes required */
- p->ainsn.boostable = 1;
- goto no_change;
-#else
- next_rip = regs->ip;
- break;
-#endif
- default:
- break;
- }
-
-#ifdef CONFIG_X86_32
- if (p->ainsn.boostable == 0) {
- if ((regs->ip > copy_ip) &&
- (regs->ip - copy_ip) + 5 < (MAX_INSN_SIZE + 1)) {
- /*
- * These instructions can be executed directly if it
- * jumps back to correct address.
- */
- set_jmp_op((void *)regs->ip,
- (void *)orig_ip + (regs->ip - copy_ip));
- p->ainsn.boostable = 1;
- } else {
- p->ainsn.boostable = -1;
- }
- }
-
- regs->ip = orig_ip + (regs->ip - copy_ip);
-
-no_change:
-#else
- if (next_rip) {
- regs->ip = next_rip;
- } else {
- regs->ip = orig_ip + (regs->ip - copy_ip);
- }
-#endif
- restore_btf();
-}
-
-/*
- * Interrupts are disabled on entry as trap1 is an interrupt gate and they
- * remain disabled thoroughout this function.
- */
-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, kcb);
- regs->flags |= kcb->kprobe_saved_flags;
- trace_hardirqs_fixup_flags(regs->flags);
-
- /* Restore 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, flags
- * will have TF set, in which case, continue the remaining processing
- * of do_debug, as if this is not a probe hit.
- */
- if (regs->flags & TF_MASK)
- 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();
-#ifdef CONFIG_X86_64
- const struct exception_table_entry *fixup;
-#endif
-
- switch(kcb->kprobe_status) {
- 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 ip points back to the probe address
- * and allow the page fault handler to continue as a
- * normal page fault.
- */
- regs->ip = (unsigned long)cur->addr;
- regs->flags |= kcb->kprobe_old_flags;
- 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.
- */
-#ifdef CONFIG_X86_32
- if (fixup_exception(regs))
- return 1;
-#else
- fixup = search_exception_tables(regs->ip);
- if (fixup) {
- regs->ip = fixup->fixup;
- return 1;
- }
-#endif
- /*
- * Exception couldn't be fixed up,
- * Let do_page_fault() fix it.
- */
- break;
- default:
- break;
- }
- return 0;
-}
-
-/*
- * Wrapper routine 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;
-
-#ifdef CONFIG_X86_32
- if (args->regs && user_mode_vm(args->regs))
- return ret;
-#else
- if (args->regs && user_mode(args->regs))
- return ret;
-#endif
-
- switch (val) {
- case DIE_INT3:
- if (kprobe_handler(args->regs))
- ret = NOTIFY_STOP;
- break;
- case DIE_DEBUG:
- if (post_kprobe_handler(args->regs))
- ret = NOTIFY_STOP;
- break;
- case DIE_GPF:
- /* 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();
-
- kcb->jprobe_saved_regs = *regs;
- kcb->jprobe_saved_sp = ®s->sp;
- addr = (unsigned long)(kcb->jprobe_saved_sp);
-
- /*
- * As Linus pointed out, gcc assumes that the callee
- * owns the argument space and could overwrite it, e.g.
- * tailcall optimization. So, to be absolutely safe
- * we also save and restore enough stack bytes to cover
- * the argument area.
- */
- memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr,
- MIN_STACK_SIZE(addr));
- regs->flags &= ~IF_MASK;
- trace_hardirqs_off();
- regs->ip = (unsigned long)(jp->entry);
- return 1;
-}
-
-void __kprobes jprobe_return(void)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-#ifdef CONFIG_X86_32
- asm volatile (" xchgl %%ebx,%%esp \n"
- " int3 \n"
- " .globl jprobe_return_end \n"
- " jprobe_return_end: \n"
- " nop \n"::"b"
- (kcb->jprobe_saved_sp):"memory");
-#else
- asm volatile (" xchg %%rbx,%%rsp \n"
- " int3 \n"
- " .globl jprobe_return_end \n"
- " jprobe_return_end: \n"
- " nop \n"::"b"
- (kcb->jprobe_saved_sp):"memory");
-#endif
-}
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- u8 *addr = (u8 *) (regs->ip - 1);
- unsigned long stack_addr = (unsigned long)(kcb->jprobe_saved_sp);
- struct jprobe *jp = container_of(p, struct jprobe, kp);
-
- if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) {
- if (®s->sp != kcb->jprobe_saved_sp) {
- struct pt_regs *saved_regs =
- container_of(kcb->jprobe_saved_sp,
- struct pt_regs, sp);
- printk("current sp %p does not match saved sp %p\n",
- ®s->sp, kcb->jprobe_saved_sp);
- printk("Saved registers for jprobe %p\n", jp);
- show_registers(saved_regs);
- printk("Current registers\n");
- show_registers(regs);
- BUG();
- }
- *regs = kcb->jprobe_saved_regs;
- memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack,
- MIN_STACK_SIZE(stack_addr));
- preempt_enable_no_resched();
- return 1;
- }
- return 0;
-}
-
-#ifdef CONFIG_X86_64
-static struct kprobe trampoline_p = {
- .addr = (kprobe_opcode_t *) &kretprobe_trampoline,
- .pre_handler = trampoline_probe_handler
-};
-#endif
-
-int __kprobes arch_trampoline_kprobe(struct kprobe *p)
-{
-#ifdef CONFIG_X86_64
- if (p->addr == (kprobe_opcode_t *)&kretprobe_trampoline)
- return 1;
-#endif
- return 0;
-}
-
-int __init arch_init_kprobes(void)
-{
-#ifdef CONFIG_X86_32
- return 0;
-#else
- return register_kprobe(&trampoline_p);
-#endif
-}
diff --git a/arch/x86/kernel/kprobes_64.c b/arch/x86/kernel/kprobes_64.c
deleted file mode 100644
index f195348..0000000
--- a/arch/x86/kernel/kprobes_64.c
+++ /dev/null
@@ -1,1090 +0,0 @@
-/*
- * 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, 2004
- */
-
-#include <linux/kprobes.h>
-#include <linux/ptrace.h>
-#include <linux/string.h>
-#include <linux/slab.h>
-#include <linux/preempt.h>
-#include <linux/module.h>
-#include <linux/kdebug.h>
-
-#include <asm/cacheflush.h>
-#include <asm/desc.h>
-#include <asm/pgtable.h>
-#include <asm/uaccess.h>
-#include <asm/alternative.h>
-
-void jprobe_return_end(void);
-static void __kprobes arch_copy_kprobe(struct kprobe *p);
-
-DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
-DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
-
-struct kretprobe_blackpoint kretprobe_blacklist[] = {
- {"__switch_to", }, /* This function switches only current task, but
- doesn't switch kernel stack.*/
- {NULL, NULL} /* Terminator */
-};
-const int kretprobe_blacklist_size = ARRAY_SIZE(kretprobe_blacklist);
-
-#define W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- (((b0##UL << 0x0)|(b1##UL << 0x1)|(b2##UL << 0x2)|(b3##UL << 0x3) | \
- (b4##UL << 0x4)|(b5##UL << 0x5)|(b6##UL << 0x6)|(b7##UL << 0x7) | \
- (b8##UL << 0x8)|(b9##UL << 0x9)|(ba##UL << 0xa)|(bb##UL << 0xb) | \
- (bc##UL << 0xc)|(bd##UL << 0xd)|(be##UL << 0xe)|(bf##UL << 0xf)) \
- << (r % sizeof(unsigned long)))
-
-#define R1(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) |
-#define R3(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) |
-#define R4(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf),
-#define RF(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf)
-
-#ifdef CONFIG_X86_32
-#define R2(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf),
-#else
-#define R2(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) \
- W(r, b0, b1, b2, b3, b4, b5, b6, b7, b8, b9, ba, bb, bc, bd, be, bf) |
-#endif
-
-/*
- * Undefined/reserved opcodes, conditional jump, Opcode Extension
- * Groups, and some special opcodes can not be boost.
- */
-static const unsigned long
-twobyte_is_boostable[256 / sizeof(unsigned long)] = {
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
- /* ----------------------------------------------- */
- R1(0x00, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, 0, 0, 0, 0, 0) /* 00 */
- R2(0x10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 10 */
- R3(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 20 */
- R4(0x30, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 30 */
- R1(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 40 */
- R2(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 50 */
- R3(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1) /* 60 */
- R4(0x70, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* 70 */
- R1(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 80 */
- R2(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 90 */
- R3(0xa0, 1, 1, 0, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) /* a0 */
- R4(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) /* b0 */
- R1(0xc0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) /* c0 */
- R2(0xd0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) /* d0 */
- R3(0xe0, 0, 1, 1, 0, 0, 1, 0, 0, 1, 1, 0, 1, 1, 1, 0, 1) /* e0 */
- RF(0xf0, 0, 1, 1, 1, 0, 1, 0, 0, 1, 1, 1, 0, 1, 1, 1, 0) /* f0 */
- /* ----------------------------------------------- */
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
-};
-
-static const unsigned long
-onebyte_has_modrm[256 / sizeof(unsigned long)] = {
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
- /* ----------------------------------------------- */
- R1(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 00 */
- R2(0x10, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 10 */
- R3(0x20, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 20 */
- R4(0x30, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0) /* 30 */
- R1(0x40, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 40 */
- R2(0x50, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 50 */
- R3(0x60, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 0, 0, 0) /* 60 */
- R4(0x70, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 70 */
- R1(0x80, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 80 */
- R2(0x90, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 90 */
- R3(0xa0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* a0 */
- R4(0xb0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* b0 */
- R1(0xc0, 1, 1, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) /* c0 */
- R2(0xd0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1) /* d0 */
- R3(0xe0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* e0 */
- RF(0xf0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 0, 1, 1) /* f0 */
- /* ----------------------------------------------- */
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
-};
-
-static const unsigned long
-twobyte_has_modrm[256 / sizeof(unsigned long)] = {
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
- /* ----------------------------------------------- */
- R1(0x00, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1) /* 0f */
- R2(0x10, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0) /* 1f */
- R3(0x20, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 1, 1, 1) /* 2f */
- R4(0x30, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 3f */
- R1(0x40, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 4f */
- R2(0x50, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 5f */
- R3(0x60, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 6f */
- R4(0x70, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1) /* 7f */
- R1(0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0) /* 8f */
- R2(0x90, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* 9f */
- R3(0xa0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, 1, 1, 1) /* af */
- R4(0xb0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 1, 1, 1, 1) /* bf */
- R1(0xc0, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0) /* cf */
- R2(0xd0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* df */
- R3(0xe0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1) /* ef */
- RF(0xf0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0) /* ff */
- /* ----------------------------------------------- */
- /* 0 1 2 3 4 5 6 7 8 9 a b c d e f */
-};
-
-#undef W
-#undef R1
-#undef R2
-#undef R3
-#undef R4
-#undef RF
-
-/* insert a jmp code */
-static inline void set_jmp_op(void *from, void *to)
-{
- struct __arch_jmp_op {
- char op;
- long raddr;
- } __attribute__((packed)) *jop;
- jop = (struct __arch_jmp_op *)from;
- jop->raddr = (long)(to) - ((long)(from) + 5);
- jop->op = RELATIVEJUMP_INSTRUCTION;
-}
-
-/*
- * returns non-zero if opcodes can be boosted.
- */
-static inline int can_boost(kprobe_opcode_t *opcodes)
-{
- kprobe_opcode_t opcode;
- kprobe_opcode_t *orig_opcodes = opcodes;
-retry:
- if (opcodes - orig_opcodes > MAX_INSN_SIZE)
- return 0;
- opcode = *(opcodes++);
-
- /* 2nd-byte opcode */
- if (opcode == 0x0f) {
- if (opcodes - orig_opcodes > MAX_INSN_SIZE)
- return 0;
- return test_bit(*opcodes, twobyte_is_boostable);
- }
-
- switch (opcode & 0xf0) {
- case 0x60:
- if (0x63 < opcode && opcode < 0x67)
- goto retry; /* prefixes */
- /* can't boost Address-size override and bound */
- return (opcode != 0x62 && opcode != 0x67);
- case 0x70:
- return 0; /* can't boost conditional jump */
- case 0xc0:
- /* can't boost software-interruptions */
- return (0xc1 < opcode && opcode < 0xcc) || opcode == 0xcf;
- case 0xd0:
- /* can boost AA* and XLAT */
- return (opcode == 0xd4 || opcode == 0xd5 || opcode == 0xd7);
- case 0xe0:
- /* can boost in/out and absolute jmps */
- return ((opcode & 0x04) || opcode == 0xea);
- case 0xf0:
- if ((opcode & 0x0c) == 0 && opcode != 0xf1)
- goto retry; /* lock/rep(ne) prefix */
- /* clear and set flags can be boost */
- return (opcode == 0xf5 || (0xf7 < opcode && opcode < 0xfe));
- default:
- if (opcode == 0x26 || opcode == 0x36 || opcode == 0x3e)
- goto retry; /* prefixes */
- /* can't boost CS override and call */
- return (opcode != 0x2e && opcode != 0x9a);
- }
-}
-
-/*
- * returns non-zero if opcode modifies the interrupt flag.
- */
-static int __kprobes is_IF_modifier(kprobe_opcode_t *insn)
-{
- switch (*insn) {
- case 0xfa: /* cli */
- case 0xfb: /* sti */
- case 0xcf: /* iret/iretd */
- case 0x9d: /* popf/popfd */
- return 1;
- }
-
-#ifdef CONFIG_X86_64
- /* REX prefix */
- if (*insn >= 0x40 && *insn <= 0x4f && *++insn == 0xcf)
- return 1;
-#endif
- return 0;
-}
-
-int __kprobes arch_prepare_kprobe(struct kprobe *p)
-{
- /* insn: must be on special executable page on x86_32|64. */
- p->ainsn.insn = get_insn_slot();
- if (!p->ainsn.insn)
- return -ENOMEM;
-
- arch_copy_kprobe(p);
- return 0;
-}
-
-/*
- * Determine if the instruction uses the %rip-relative addressing mode.
- * If it does, return the address of the 32-bit displacement word.
- * If not, return null.
- */
-static s32 __kprobes *is_riprel(u8 *insn)
-{
- int need_modrm;
-
- /* Skip legacy instruction prefixes. */
- while (1) {
- switch (*insn) {
- case 0x66:
- case 0x67:
- case 0x2e:
- case 0x3e:
- case 0x26:
- case 0x64:
- case 0x65:
- case 0x36:
- case 0xf0:
- case 0xf3:
- case 0xf2:
- ++insn;
- continue;
- }
- break;
- }
-
- /* Skip REX instruction prefix. */
- if ((*insn & 0xf0) == 0x40)
- ++insn;
-
- if (*insn == 0x0f) { /* Two-byte opcode. */
- ++insn;
- need_modrm = test_bit(*insn, twobyte_has_modrm);
- } else { /* One-byte opcode. */
- need_modrm = test_bit(*insn, onebyte_has_modrm);
- }
-
- if (need_modrm) {
- u8 modrm = *++insn;
- if ((modrm & 0xc7) == 0x05) { /* %rip+disp32 addressing mode */
- /* Displacement follows ModRM byte. */
- return (s32 *) ++insn;
- }
- }
-
- /* No %rip-relative addressing mode here. */
- return NULL;
-}
-
-static void __kprobes arch_copy_kprobe(struct kprobe *p)
-{
-#ifdef CONFIG_X86_32
- memcpy(p->ainsn.insn, p->addr, (MAX_INSN_SIZE + 1) * sizeof(kprobe_opcode_t));
- p->opcode = *p->addr;
- if (can_boost(p->addr)) {
- p->ainsn.boostable = 0;
- } else {
- p->ainsn.boostable = -1;
- }
-#else
- s32 *ripdisp;
- memcpy(p->ainsn.insn, p->addr, MAX_INSN_SIZE);
- ripdisp = is_riprel(p->ainsn.insn);
- if (ripdisp) {
- /*
- * The copied instruction uses the %rip-relative
- * addressing mode. Adjust the displacement for the
- * difference between the original location of this
- * instruction and the location of the copy that will
- * actually be run. The tricky bit here is making sure
- * that the sign extension happens correctly in this
- * calculation, since we need a signed 32-bit result to
- * be sign-extended to 64 bits when it's added to the
- * %rip value and yield the same 64-bit result that the
- * sign-extension of the original signed 32-bit
- * displacement would have given.
- */
- s64 disp = (u8 *) p->addr + *ripdisp - (u8 *) p->ainsn.insn;
- BUG_ON((s64) (s32) disp != disp); /* Sanity check. */
- *ripdisp = disp;
- }
- p->opcode = *p->addr;
-#endif
-}
-
-void __kprobes arch_arm_kprobe(struct kprobe *p)
-{
- text_poke(p->addr, ((unsigned char []){BREAKPOINT_INSTRUCTION}), 1);
-}
-
-void __kprobes arch_disarm_kprobe(struct kprobe *p)
-{
- text_poke(p->addr, &p->opcode, 1);
-}
-
-void __kprobes arch_remove_kprobe(struct kprobe *p)
-{
- mutex_lock(&kprobe_mutex);
-#ifdef CONFIG_X86_32
- free_insn_slot(p->ainsn.insn, (p->ainsn.boostable == 1));
-#else
- free_insn_slot(p->ainsn.insn, 0);
-#endif
- mutex_unlock(&kprobe_mutex);
-}
-
-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.old_flags = kcb->kprobe_old_flags;
- kcb->prev_kprobe.saved_flags = kcb->kprobe_saved_flags;
-}
-
-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_old_flags = kcb->prev_kprobe.old_flags;
- kcb->kprobe_saved_flags = kcb->prev_kprobe.saved_flags;
-}
-
-static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
- struct kprobe_ctlblk *kcb)
-{
- __get_cpu_var(current_kprobe) = p;
- kcb->kprobe_saved_flags = kcb->kprobe_old_flags
- = (regs->flags & (TF_MASK | IF_MASK));
- if (is_IF_modifier(p->ainsn.insn))
- kcb->kprobe_saved_flags &= ~IF_MASK;
-}
-
-static __always_inline void clear_btf(void)
-{
- if (test_thread_flag(TIF_DEBUGCTLMSR))
-#ifdef CONFIG_X86_32
- wrmsr(MSR_IA32_DEBUGCTLMSR, 0, 0);
-#else
- wrmsrl(MSR_IA32_DEBUGCTLMSR, 0);
-#endif
-}
-
-static __always_inline void restore_btf(void)
-{
- if (test_thread_flag(TIF_DEBUGCTLMSR))
-#ifdef CONFIG_X86_32
- wrmsr(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr, 0);
-#else
- wrmsrl(MSR_IA32_DEBUGCTLMSR, current->thread.debugctlmsr);
-#endif
-}
-
-static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
-{
- clear_btf();
- regs->flags |= TF_MASK;
- regs->flags &= ~IF_MASK;
- /*single step inline if the instruction is an int3*/
- if (p->opcode == BREAKPOINT_INSTRUCTION)
- regs->ip = (unsigned long)p->addr;
- else
- regs->ip = (unsigned long)p->ainsn.insn;
-}
-
-/* Called with kretprobe_lock held */
-void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
- struct pt_regs *regs)
-{
- unsigned long *sara = ®s->sp;
-
- ri->ret_addr = (kprobe_opcode_t *) *sara;
- /* Replace the return addr with trampoline addr */
- *sara = (unsigned long) &kretprobe_trampoline;
-}
-
-/*
- * Interrupts are disabled on entry as trap3 is an interrupt gate and they
- * remain disabled thorough out this function.
- */
-static int __kprobes kprobe_handler(struct pt_regs *regs)
-{
- struct kprobe *p;
- int ret = 0;
- kprobe_opcode_t *addr;
- struct kprobe_ctlblk *kcb;
-
- addr = (kprobe_opcode_t *)(regs->ip - sizeof(kprobe_opcode_t));
-
- /*
- * 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->flags &= ~TF_MASK;
- regs->flags |= kcb->kprobe_saved_flags;
- goto no_kprobe;
-#ifdef CONFIG_X86_32
- }
- /* 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
- } else if (kcb->kprobe_status == KPROBE_HIT_SSDONE) {
- /* TODO: Provide re-entrancy from
- * post_kprobes_handler() and avoid exception
- * stack corruption while single-stepping on
- * the instruction of the new probe.
- */
- arch_disarm_kprobe(p);
- regs->ip = (unsigned long)p->addr;
- reset_current_kprobe();
- ret = 1;
- } else {
- /* We have reentered the kprobe_handler(), since
- * another probe was hit while within the
- * handler. We here save the original kprobe
- * variables and just single step on 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;
- }
-#endif
- } else {
- if (*addr != BREAKPOINT_INSTRUCTION) {
- /* The breakpoint instruction was removed by
- * another cpu right after we hit, no further
- * handling of this interrupt is appropriate
- */
-#ifdef CONFIG_X86_32
- regs->ip -= sizeof(kprobe_opcode_t);
-#else
- regs->ip = (unsigned long)addr;
-#endif
- ret = 1;
- goto no_kprobe;
- }
- 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) {
- if (*addr != BREAKPOINT_INSTRUCTION) {
- /*
- * The breakpoint instruction was removed right
- * after we hit it. Another cpu has removed
- * either a probepoint or a debugger breakpoint
- * at this address. In either case, no further
- * handling of this interrupt is appropriate.
- * Back up over the (now missing) int3 and run
- * the original instruction.
- */
-#ifdef CONFIG_X86_32
- regs->ip -= sizeof(kprobe_opcode_t);
-#else
- regs->ip = (unsigned long)addr;
-#endif
- ret = 1;
- }
- /* Not one of ours: let kernel handle it */
- goto no_kprobe;
- }
-
- set_current_kprobe(p, regs, kcb);
- kcb->kprobe_status = KPROBE_HIT_ACTIVE;
-
- if (p->pre_handler && p->pre_handler(p, regs))
- /* handler has already set things up, so skip ss setup */
- return 1;
-
-ss_probe:
-#if defined(CONFIG_X86_32) && (!defined(CONFIG_PREEMPT) || defined(CONFIG_PM))
- if (p->ainsn.boostable == 1 && !p->post_handler){
- /* Boost up -- we can execute copied instructions directly */
- reset_current_kprobe();
- regs->ip = (unsigned long)p->ainsn.insn;
- preempt_enable_no_resched();
- return 1;
- }
-#endif
- prepare_singlestep(p, regs);
- kcb->kprobe_status = KPROBE_HIT_SS;
- return 1;
-
-no_kprobe:
- preempt_enable_no_resched();
- return ret;
-}
-
-/*
- * For function-return probes, init_kprobes() establishes a probepoint
- * here. When a retprobed function returns, this probe is hit and
- * trampoline_probe_handler() runs, calling the kretprobe's handler.
- */
-void kretprobe_trampoline_holder(void)
-{
-#ifdef CONFIG_X86_32
- asm volatile ( ".global kretprobe_trampoline\n"
- "kretprobe_trampoline: \n"
- " pushf\n"
- /* skip cs, ip, orig_ax */
- " subl $12, %esp\n"
- " pushl %fs\n"
- " pushl %ds\n"
- " pushl %es\n"
- " pushl %eax\n"
- " pushl %ebp\n"
- " pushl %edi\n"
- " pushl %esi\n"
- " pushl %edx\n"
- " pushl %ecx\n"
- " pushl %ebx\n"
- " movl %esp, %eax\n"
- " call trampoline_handler\n"
- /* move flags to cs */
- " movl 52(%esp), %edx\n"
- " movl %edx, 48(%esp)\n"
- /* save true return address on flags */
- " movl %eax, 52(%esp)\n"
- " popl %ebx\n"
- " popl %ecx\n"
- " popl %edx\n"
- " popl %esi\n"
- " popl %edi\n"
- " popl %ebp\n"
- " popl %eax\n"
- /* skip ip, orig_ax, es, ds, fs */
- " addl $20, %esp\n"
- " popf\n"
- " ret\n");
-#else
- asm volatile ( ".global kretprobe_trampoline\n"
- "kretprobe_trampoline: \n"
- "nop\n");
-#endif
-}
-
-/*
- * Called when we hit the probe point at kretprobe_trampoline
- */
-#ifdef CONFIG_X86_32
-void *__kprobes trampoline_handler(struct pt_regs *regs)
-#else
-int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs)
-#endif
-{
- 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);
-#ifdef CONFIG_X86_32
- /* fixup registers */
- regs->cs = __KERNEL_CS | get_kernel_rpl();
- regs->ip = trampoline_address;
- regs->orig_ax = 0xffffffff;
-#endif
- /*
- * 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;
-#ifdef CONFIG_X86_32
- if (ri->rp && ri->rp->handler) {
- __get_cpu_var(current_kprobe) = &ri->rp->kp;
- get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE;
- ri->rp->handler(ri, regs);
- __get_cpu_var(current_kprobe) = NULL;
- }
-#else
- if (ri->rp && ri->rp->handler)
- ri->rp->handler(ri, regs);
-#endif
- 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);
-#ifdef CONFIG_X86_64
- regs->ip = orig_ret_address;
- reset_current_kprobe();
-#endif
- spin_unlock_irqrestore(&kretprobe_lock, flags);
-#ifdef CONFIG_X86_64
- preempt_enable_no_resched();
-#endif
- hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
- hlist_del(&ri->hlist);
- kfree(ri);
- }
-
-#ifdef CONFIG_X86_32
- return (void*)orig_ret_address;
-#else
- /*
- * 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;
-#endif
-}
-
-/*
- * Called after single-stepping. p->addr is the address of the
- * instruction whose first byte has been replaced by the "int 3"
- * 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.
- *
- * This function prepares to return from the post-single-step
- * interrupt. We have to fix up the stack as follows:
- *
- * 0) Except in the case of absolute or indirect jump or call instructions,
- * the new ip is relative to the copied instruction. We need to make
- * it relative to the original instruction.
- *
- * 1) If the single-stepped instruction was pushfl, then the TF and IF
- * flags are set in the just-pushed flags, and may need to be cleared.
- *
- * 2) If the single-stepped instruction was a call, the return address
- * that is atop the stack is the address following the copied instruction.
- * We need to make it the address following the original instruction.
- *
- * This function also checks instruction size for preparing direct execution.
- */
-static void __kprobes resume_execution(struct kprobe *p,
- struct pt_regs *regs, struct kprobe_ctlblk *kcb)
-{
- unsigned long *tos = ®s->sp;
- unsigned long next_rip = 0;
- unsigned long copy_ip = (unsigned long)p->ainsn.insn;
- unsigned long orig_ip = (unsigned long)p->addr;
- kprobe_opcode_t *insn = p->ainsn.insn;
-
-#ifdef CONFIG_X86_64
- /*skip the REX prefix*/
- if (*insn >= 0x40 && *insn <= 0x4f)
- insn++;
-#endif
-
- regs->flags &= ~TF_MASK;
- switch (*insn) {
- case 0x9c: /* pushfl */
- *tos &= ~(TF_MASK | IF_MASK);
- *tos |= kcb->kprobe_old_flags;
- break;
- case 0xc2: /* ret/lret */
- case 0xc3:
- case 0xca:
- case 0xcb:
-#ifdef CONFIG_X86_32
- case 0xcf: /* iret */
- /* ip is already adjusted, no more changes required */
- p->ainsn.boostable = 1;
- goto no_change;
-#else
- /* ip is already adjusted, no more changes required*/
- return;
-#endif
- case 0xe8: /* call relative - Fix return addr */
- *tos = orig_ip + (*tos - copy_ip);
- break;
-#ifdef CONFIG_X86_32
- case 0x9a: /* call absolute -- same as call absolute, indirect */
- *tos = orig_ip + (*tos - copy_ip);
- goto no_change;
-#endif
- case 0xff:
-#ifdef CONFIG_X86_32
- if ((insn[1] & 0x30) == 0x10) {
- /*
- * call absolute, indirect
- * Fix return addr; ip is correct.
- * But this is not boostable
- */
- *tos = orig_ip + (*tos - copy_ip);
- goto no_change;
- } else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
- ((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
- /* ip is correct. And this is boostable */
- p->ainsn.boostable = 1;
- goto no_change;
- }
-#else
- if ((insn[1] & 0x30) == 0x10) {
- /* call absolute, indirect */
- /* Fix return addr; ip is correct. */
- next_rip = regs->ip;
- *tos = orig_ip + (*tos - copy_ip);
- } else if (((insn[1] & 0x31) == 0x20) || /* jmp near, absolute indirect */
- ((insn[1] & 0x31) == 0x21)) { /* jmp far, absolute indirect */
- /* ip is correct. */
- next_rip = regs->ip;
- }
-#endif
- break;
- case 0xea: /* jmp absolute -- ip is correct */
-#ifdef CONFIG_X86_32
- /* ip is already adjusted, no more changes required */
- p->ainsn.boostable = 1;
- goto no_change;
-#else
- next_rip = regs->ip;
- break;
-#endif
- default:
- break;
- }
-
-#ifdef CONFIG_X86_32
- if (p->ainsn.boostable == 0) {
- if ((regs->ip > copy_ip) &&
- (regs->ip - copy_ip) + 5 < (MAX_INSN_SIZE + 1)) {
- /*
- * These instructions can be executed directly if it
- * jumps back to correct address.
- */
- set_jmp_op((void *)regs->ip,
- (void *)orig_ip + (regs->ip - copy_ip));
- p->ainsn.boostable = 1;
- } else {
- p->ainsn.boostable = -1;
- }
- }
-
- regs->ip = orig_ip + (regs->ip - copy_ip);
-
-no_change:
-#else
- if (next_rip) {
- regs->ip = next_rip;
- } else {
- regs->ip = orig_ip + (regs->ip - copy_ip);
- }
-#endif
- restore_btf();
-}
-
-/*
- * Interrupts are disabled on entry as trap1 is an interrupt gate and they
- * remain disabled thoroughout this function.
- */
-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, kcb);
- regs->flags |= kcb->kprobe_saved_flags;
- trace_hardirqs_fixup_flags(regs->flags);
-
- /* Restore 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, flags
- * will have TF set, in which case, continue the remaining processing
- * of do_debug, as if this is not a probe hit.
- */
- if (regs->flags & TF_MASK)
- 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();
-#ifdef CONFIG_X86_64
- const struct exception_table_entry *fixup;
-#endif
-
- switch(kcb->kprobe_status) {
- 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 ip points back to the probe address
- * and allow the page fault handler to continue as a
- * normal page fault.
- */
- regs->ip = (unsigned long)cur->addr;
- regs->flags |= kcb->kprobe_old_flags;
- 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.
- */
-#ifdef CONFIG_X86_32
- if (fixup_exception(regs))
- return 1;
-#else
- fixup = search_exception_tables(regs->ip);
- if (fixup) {
- regs->ip = fixup->fixup;
- return 1;
- }
-#endif
- /*
- * Exception couldn't be fixed up,
- * Let do_page_fault() fix it.
- */
- break;
- default:
- break;
- }
- return 0;
-}
-
-/*
- * Wrapper routine 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;
-
-#ifdef CONFIG_X86_32
- if (args->regs && user_mode_vm(args->regs))
- return ret;
-#else
- if (args->regs && user_mode(args->regs))
- return ret;
-#endif
-
- switch (val) {
- case DIE_INT3:
- if (kprobe_handler(args->regs))
- ret = NOTIFY_STOP;
- break;
- case DIE_DEBUG:
- if (post_kprobe_handler(args->regs))
- ret = NOTIFY_STOP;
- break;
- case DIE_GPF:
- /* 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();
-
- kcb->jprobe_saved_regs = *regs;
- kcb->jprobe_saved_sp = ®s->sp;
- addr = (unsigned long)(kcb->jprobe_saved_sp);
-
- /*
- * As Linus pointed out, gcc assumes that the callee
- * owns the argument space and could overwrite it, e.g.
- * tailcall optimization. So, to be absolutely safe
- * we also save and restore enough stack bytes to cover
- * the argument area.
- */
- memcpy(kcb->jprobes_stack, (kprobe_opcode_t *)addr,
- MIN_STACK_SIZE(addr));
- regs->flags &= ~IF_MASK;
- trace_hardirqs_off();
- regs->ip = (unsigned long)(jp->entry);
- return 1;
-}
-
-void __kprobes jprobe_return(void)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
-#ifdef CONFIG_X86_32
- asm volatile (" xchgl %%ebx,%%esp \n"
- " int3 \n"
- " .globl jprobe_return_end \n"
- " jprobe_return_end: \n"
- " nop \n"::"b"
- (kcb->jprobe_saved_sp):"memory");
-#else
- asm volatile (" xchg %%rbx,%%rsp \n"
- " int3 \n"
- " .globl jprobe_return_end \n"
- " jprobe_return_end: \n"
- " nop \n"::"b"
- (kcb->jprobe_saved_sp):"memory");
-#endif
-}
-
-int __kprobes longjmp_break_handler(struct kprobe *p, struct pt_regs *regs)
-{
- struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
- u8 *addr = (u8 *) (regs->ip - 1);
- unsigned long stack_addr = (unsigned long)(kcb->jprobe_saved_sp);
- struct jprobe *jp = container_of(p, struct jprobe, kp);
-
- if ((addr > (u8 *) jprobe_return) && (addr < (u8 *) jprobe_return_end)) {
- if (®s->sp != kcb->jprobe_saved_sp) {
- struct pt_regs *saved_regs =
- container_of(kcb->jprobe_saved_sp,
- struct pt_regs, sp);
- printk("current sp %p does not match saved sp %p\n",
- ®s->sp, kcb->jprobe_saved_sp);
- printk("Saved registers for jprobe %p\n", jp);
- show_registers(saved_regs);
- printk("Current registers\n");
- show_registers(regs);
- BUG();
- }
- *regs = kcb->jprobe_saved_regs;
- memcpy((kprobe_opcode_t *) stack_addr, kcb->jprobes_stack,
- MIN_STACK_SIZE(stack_addr));
- preempt_enable_no_resched();
- return 1;
- }
- return 0;
-}
-
-#ifdef CONFIG_X86_64
-static struct kprobe trampoline_p = {
- .addr = (kprobe_opcode_t *) &kretprobe_trampoline,
- .pre_handler = trampoline_probe_handler
-};
-#endif
-
-int __kprobes arch_trampoline_kprobe(struct kprobe *p)
-{
-#ifdef CONFIG_X86_64
- if (p->addr == (kprobe_opcode_t *)&kretprobe_trampoline)
- return 1;
-#endif
- return 0;
-}
-
-int __init arch_init_kprobes(void)
-{
-#ifdef CONFIG_X86_32
- return 0;
-#else
- return register_kprobe(&trampoline_p);
-#endif
-}
--
1.5.4.rc0.1083.gf568
next reply other threads:[~2007-12-15 8:46 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-15 8:45 Harvey Harrison [this message]
2007-12-15 8:50 ` FInal kprobes rollup patches Ingo Molnar
2007-12-15 9:04 ` Harvey Harrison
2007-12-15 13:12 ` Ingo Molnar
2007-12-17 14:12 ` Srikar Dronamraju
2007-12-17 14:13 ` Masami Hiramatsu
2007-12-17 14:30 ` Final " Ingo Molnar
2007-12-17 15:29 ` Masami Hiramatsu
2007-12-17 16:06 ` Ingo Molnar
2007-12-17 16:19 ` Masami Hiramatsu
2007-12-17 20:17 ` Harvey Harrison
2007-12-17 14:22 ` FInal " Srikar Dronamraju
2007-12-17 19:20 ` Harvey Harrison
2007-12-17 21:28 ` Masami Hiramatsu
2007-12-17 21:36 ` Harvey Harrison
2007-12-17 21:52 ` Masami Hiramatsu
2007-12-17 22:00 ` Harvey Harrison
2007-12-17 23:14 ` Masami Hiramatsu
2007-12-17 23:27 ` Harvey Harrison
2007-12-17 23:56 ` Masami Hiramatsu
2007-12-18 0:27 ` Masami Hiramatsu
2007-12-18 2:15 ` Harvey Harrison
2007-12-18 3:10 ` [PATCH] x86: kprobes use stack_addr() macro Harvey Harrison
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