x86: support hooking SYSCALL/SYSENTER instructions. we no longer share the SYSCALL callback with interrupt instructions

This commit is contained in:
Nguyen Anh Quynh 2015-08-23 01:19:40 +08:00
parent 3eeda8c8eb
commit e1baf2f36b
7 changed files with 41 additions and 15 deletions

View file

@ -408,15 +408,15 @@ def test_x86_64_syscall():
# write machine code to be emulated to memory
mu.mem_write(ADDRESS, X86_CODE64_SYSCALL)
def hook_intr(mu, intno, user_data):
def hook_syscall(mu, user_data):
rax = mu.reg_read(X86_REG_RAX)
if intno == 80 and rax == 0x100:
if rax == 0x100:
mu.reg_write(X86_REG_RAX, 0x200)
else:
print('ERROR: was not expecting rax=%d in syscall' % rax)
# hook interrupts for syscall
mu.hook_add(UC_HOOK_INTR, hook_intr)
mu.hook_add(UC_HOOK_INSN, hook_syscall, None, X86_INS_SYSCALL)
# syscall handler is expecting rax=0x100
mu.reg_write(X86_REG_RAX, 0x100)

View file

@ -231,6 +231,7 @@ UC_HOOK_INSN_IN_CB = ctypes.CFUNCTYPE(ctypes.c_uint32, ctypes.c_size_t, ctypes.c
ctypes.c_int, ctypes.c_void_p)
UC_HOOK_INSN_OUT_CB = ctypes.CFUNCTYPE(None, ctypes.c_size_t, ctypes.c_uint32, \
ctypes.c_int, ctypes.c_uint32, ctypes.c_void_p)
UC_HOOK_INSN_SYSCALL_CB = ctypes.CFUNCTYPE(None, ctypes.c_size_t, ctypes.c_void_p)
# access to error code via @errno of UcError
@ -383,6 +384,12 @@ class Uc(object):
cb(self, port, size, value, data)
def _hook_insn_syscall_cb(self, handle, user_data):
# call user's callback with self object
(cb, data) = self._callbacks[user_data]
cb(self, data)
# add a hook
def hook_add(self, htype, callback, user_data=None, arg1=1, arg2=0):
_h2 = ctypes.c_size_t()
@ -413,6 +420,8 @@ class Uc(object):
cb = ctypes.cast(UC_HOOK_INSN_IN_CB(self._hook_insn_in_cb), UC_HOOK_INSN_IN_CB)
if arg1 == x86_const.X86_INS_OUT: # OUT instruction
cb = ctypes.cast(UC_HOOK_INSN_OUT_CB(self._hook_insn_out_cb), UC_HOOK_INSN_OUT_CB)
if arg1 in (x86_const.X86_INS_SYSCALL, x86_const.X86_INS_SYSENTER): # SYSCALL/SYSENTER instruction
cb = ctypes.cast(UC_HOOK_INSN_SYSCALL_CB(self._hook_insn_syscall_cb), UC_HOOK_INSN_SYSCALL_CB)
status = _uc.uc_hook_add(self._uch, ctypes.byref(_h2), htype, \
cb, ctypes.cast(self._callback_count, ctypes.c_void_p), insn)
elif htype == UC_HOOK_INTR:

View file

@ -146,6 +146,7 @@ struct uc_struct {
int hook_intr_idx; // for handling interrupt
int hook_out_idx; // for handling OUT instruction (X86)
int hook_in_idx; // for handling IN instruction (X86)
int hook_syscall_idx; // for handling SYSCALL/SYSENTER (X86)
bool init_tcg; // already initialized local TCGv variables?

View file

@ -19,6 +19,9 @@ extern "C" {
#include "platform.h"
// Handle to use with all APIs
typedef size_t uch;
#include "m68k.h"
#include "x86.h"
#include "arm.h"
@ -65,9 +68,6 @@ extern "C" {
// 1 milisecond = 1000 nanoseconds
#define UC_MILISECOND_SCALE 1000
// Handle using with all API
typedef size_t uch;
// Architecture type
typedef enum uc_arch {
UC_ARCH_ARM = 1, // ARM architecture (including Thumb, Thumb-2)

View file

@ -8,6 +8,10 @@
extern "C" {
#endif
// Callback function for tracing SYSCALL/SYSENTER (for uc_hook_intr())
// @user_data: user data passed to tracing APIs.
typedef void (*uc_cb_insn_syscall_t)(uch handle, void *user_data);
//> X86 registers
typedef enum x86_reg {
X86_REG_INVALID = 0,

View file

@ -945,15 +945,15 @@ void helper_syscall(CPUX86State *env, int next_eip_addend)
#else
void helper_syscall(CPUX86State *env, int next_eip_addend)
{
// Unicorn: call interrupt callback if registered
struct uc_struct *uc = env->uc;
if (uc->hook_intr_idx) {
((uc_cb_hookintr_t)uc->hook_callbacks[uc->hook_intr_idx].callback)(
(uch)uc, 80,
uc->hook_callbacks[uc->hook_intr_idx].user_data);
env->eip += next_eip_addend;
return;
}
// Unicorn: call interrupt callback if registered
struct uc_struct *uc = env->uc;
if (uc->hook_syscall_idx) {
((uc_cb_insn_syscall_t)uc->hook_callbacks[uc->hook_syscall_idx].callback)(
(uch)uc, uc->hook_callbacks[uc->hook_syscall_idx].user_data);
env->eip += next_eip_addend;
}
return;
int selector;

12
uc.c
View file

@ -645,6 +645,18 @@ static uc_err _hook_insn(struct uc_struct *uc, unsigned int insn_id, void *callb
return UC_ERR_OK;
} else
return UC_ERR_OOM;
case X86_INS_SYSCALL:
case X86_INS_SYSENTER:
// FIXME: only one event handler at the same time
i = hook_find_new(uc);
if (i) {
uc->hook_callbacks[i].callback = callback;
uc->hook_callbacks[i].user_data = user_data;
*evh = i;
uc->hook_syscall_idx = i;
return UC_ERR_OK;
} else
return UC_ERR_OOM;
}
break;
}