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| Current Path : /usr/share/systemtap/tapset/x86_64/ |
| Current File : //usr/share/systemtap/tapset/x86_64/registers.stp |
%{
/* Set to include regparm field in probe context in translate.cxx. */
#ifndef STAP_NEED_REGPARM
#define STAP_NEED_REGPARM 1
#endif
%}
@__private30 global _reg_offsets[21], _r32_offsets[10], _r16_offsets[13],
_r8_offsets[8]
probe init {
/* Same order as pt_regs */
_reg_offsets["r15"] = 0
_reg_offsets["r14"] = 8
_reg_offsets["r13"] = 16
_reg_offsets["r12"] = 24
_reg_offsets["rbp"] = 32
_reg_offsets["rbx"] = 40
_reg_offsets["r11"] = 48
_reg_offsets["r10"] = 56
_reg_offsets["r9"] = 64
_reg_offsets["r8"] = 72
_reg_offsets["rax"] = 80
_reg_offsets["rcx"] = 88
_reg_offsets["rdx"] = 96
_reg_offsets["rsi"] = 104
_reg_offsets["rdi"] = 112
_reg_offsets["orig_rax"] = 120
_reg_offsets["rip"] = 128
_reg_offsets["xcs"] = 136
_reg_offsets["eflags"] = 144
_reg_offsets["rsp"] = 152
_reg_offsets["xss"] = 160
_r32_offsets["ebp"] = 32
_r32_offsets["ebx"] = 40
_r32_offsets["eax"] = 80
_r32_offsets["ecx"] = 88
_r32_offsets["edx"] = 96
_r32_offsets["esi"] = 104
_r32_offsets["edi"] = 112
_r32_offsets["orig_eax"] = 120
_r32_offsets["eip"] = 128
_r32_offsets["esp"] = 152
_r16_offsets["bp"] = 32
_r16_offsets["bx"] = 40
_r16_offsets["ax"] = 80
_r16_offsets["cx"] = 88
_r16_offsets["dx"] = 96
_r16_offsets["si"] = 104
_r16_offsets["di"] = 112
_r16_offsets["orig_ax"] = 120
_r16_offsets["ip"] = 128
_r16_offsets["cs"] = 136
_r16_offsets["flags"] = 144
_r16_offsets["sp"] = 152
_r16_offsets["ss"] = 160
_r8_offsets["al"] = 80
_r8_offsets["ah"] = 81
_r8_offsets["bl"] = 40
_r8_offsets["bh"] = 41
_r8_offsets["cl"] = 88
_r8_offsets["ch"] = 89
_r8_offsets["dl"] = 96
_r8_offsets["dh"] = 97
}
function _stp_get_register_by_offset:long (offset:long) %{ /* pure */
long value;
struct pt_regs *regs;
regs = (CONTEXT->user_mode_p ? CONTEXT->uregs : CONTEXT->kregs);
if (!regs) {
CONTEXT->last_error = "No registers available in this context";
return;
}
if (STAP_ARG_offset < 0 || STAP_ARG_offset > sizeof(struct pt_regs) - sizeof(long)) {
snprintf(CONTEXT->error_buffer, sizeof(CONTEXT->error_buffer),
"Bad register offset: %lld", (long long) STAP_ARG_offset);
CONTEXT->last_error = CONTEXT->error_buffer;
return;
}
memcpy(&value, ((char *)regs) + STAP_ARG_offset, sizeof(value));
STAP_RETVALUE = value;
%}
/*
* _stp_sign_extend32() is callable from a script function.
* __stp_sign_extend32() (in regs.c) is callable from a C function.
*/
function _stp_sign_extend32:long (value:long) %{ /* pure */
STAP_RETVALUE = __stp_sign_extend32(STAP_ARG_value);
%}
/*
* _stp_sign_extend16() is callable from a script function.
* __stp_sign_extend16() (in regs.c) is callable from a C function.
*/
function _stp_sign_extend16:long (value:long) %{ /* pure */
STAP_RETVALUE = __stp_sign_extend16(STAP_ARG_value);
%}
/*
* _stp_sign_extend8() is callable from a script function.
* __stp_sign_extend8() (in regs.c) is callable from a C function.
*/
function _stp_sign_extend8:long (value:long) %{ /* pure */
STAP_RETVALUE = __stp_sign_extend8(STAP_ARG_value);
%}
function _stp_register:long (name:string, sign_extend:long) {
reg32 = 0
reg16 = 0
reg8 = 0
assert(registers_valid(), "cannot access CPU registers in this context")
offset = _reg_offsets[name]
if (offset == 0 && !(name in _reg_offsets)) {
offset = _r32_offsets[name]
if (offset == 0 && !(name in _r32_offsets)) {
offset = _r16_offsets[name]
if (offset == 0 && !(name in _r16_offsets)) {
offset = _r8_offsets[name]
if (offset == 0 && !(name in _r8_offsets)) {
assert(0, "Unknown register: " . name)
} else {
reg8 = 1;
}
} else {
reg16 = 1;
}
} else {
reg32 = 1
}
}
value = _stp_get_register_by_offset(offset)
if (reg32) {
if (sign_extend)
value = _stp_sign_extend32(value)
else
value &= 0xffffffff
} else if (reg16) {
if (sign_extend)
value = _stp_sign_extend16(value)
else
value &= 0xffff
} else if (reg8) {
if (sign_extend)
value = _stp_sign_extend8(value)
else
value &= 0xff
}
return value
}
/* Return the named register value as a signed value. */
function register:long (name:string) {
return _stp_register(name, 1)
}
/*
* Return the named register value as an unsigned value. Specifically,
* don't sign-extend the register value when promoting it to 64 bits.
*/
function u_register:long (name:string) {
return _stp_register(name, 0)
}
/*
* Return the value of function arg #argnum (1=first arg).
* If truncate=1, mask off the top 32 bits.
* If sign_extend=1 and (truncate=1 or the probepoint we've hit is in a
* 32-bit app), sign-extend the 32-bit value.
* If force64=1, return a 64-bit value even if we're in a 32-bit app.
*/
function _stp_arg:long (argnum:long, sign_extend:long, truncate:long)
{
return _stp_arg2(argnum, sign_extend, truncate, 0)
}
function _stp_arg2:long (argnum:long, sign_extend:long, truncate:long,
force64:long)
%{ /* pure */
__label__ deref_fault;
long val;
struct pt_regs *regs;
int result, n, nr_regargs;
size_t argsz = sizeof(long);
if (CONTEXT->sregs) { /* syscall-in-pt_regs mode: kernel 4.17+ or similar */
void* valptr;
int is_32bit = _stp_is_compat_task();
regs = CONTEXT->sregs;
/* NB: kread() is probably unnecessary paranoia w.r.t. the sregs pointer. */
if (is_32bit) switch (STAP_ARG_argnum) {
/* SC_IA32_REGS_TO_ARGS / SC_X86_64_REGS_TO_ARGS */
case 1: valptr = &(regs->bx); break;
case 2: valptr = &(regs->cx); break;
case 3: valptr = &(regs->dx); break;
case 4: valptr = &(regs->si); break;
case 5: valptr = &(regs->di); break;
case 6: valptr = &(regs->bp); break;
default:
goto bad_argnum;
}
else switch (STAP_ARG_argnum) {
/* SC_IA32_REGS_TO_ARGS / SC_X86_64_REGS_TO_ARGS */
case 1: valptr = &(regs->di); break;
case 2: valptr = &(regs->si); break;
case 3: valptr = &(regs->dx); break;
case 4: valptr = &(regs->r10); break;
case 5: valptr = &(regs->r8); break;
case 6: valptr = &(regs->r9); break;
default:
goto bad_argnum;
}
val = kread((long *)valptr);
/* Here, we do sign extension / truncation, ignoring CONTEXT->user_mode_p. */
if ((STAP_ARG_truncate || _stp_is_compat_task())
&& !STAP_ARG_force64) {
if (STAP_ARG_sign_extend)
STAP_RETVALUE = (int64_t) __stp_sign_extend32(val);
else
/* High bits may be garbage. */
STAP_RETVALUE = (int64_t) (val & 0xffffffff);
} else
STAP_RETVALUE = (int64_t) val;
return;
}
// fall through in the non-sycall-mode case
regs = (CONTEXT->user_mode_p ? CONTEXT->uregs : CONTEXT->kregs);
STAP_RETVALUE = 0;
if (!regs) {
snprintf(CONTEXT->error_buffer, sizeof(CONTEXT->error_buffer),
"cannot access function args in this context");
CONTEXT->last_error = CONTEXT->error_buffer;
return;
}
if (STAP_ARG_argnum < 1)
goto bad_argnum;
n = (int) STAP_ARG_argnum;
if (CONTEXT->regparm == 0) {
/* Default */
if (CONTEXT->user_mode_p && _stp_is_compat_task())
nr_regargs = 0;
else
nr_regargs = 6;
} else
nr_regargs = (CONTEXT->regparm & _STP_REGPARM_MASK);
if (!STAP_ARG_force64 && CONTEXT->user_mode_p && _stp_is_compat_task()) {
argsz = sizeof(int);
result = _stp_get_arg32_by_number(n, nr_regargs, regs, &val);
} else {
result = _stp_get_arg64_by_number(n, nr_regargs, regs, &val);
}
switch (result) {
case 0:
/* Arg is in register. */
break;
case 1:
/* Arg is on kernel stack. */
val = kread((long *) val);
break;
case 2:
{
/* Arg is on user stack. */
const char __user *vaddr = (const char __user*) val;
if (_stp_copy_from_user((char*)&val, vaddr, argsz) != 0) {
/* Stack page not resident. */
_stp_warn("cannot access arg(%d) "
"at user stack address %p\n", n, vaddr);
STAP_RETVALUE = 0;
return;
}
break;
}
default:
goto bad_argnum;
}
/* Sign-extend etc. as needed, depending on process 32-bitness. */
if ((STAP_ARG_truncate || (CONTEXT->user_mode_p && _stp_is_compat_task()))
&& !STAP_ARG_force64) {
if (STAP_ARG_sign_extend)
STAP_RETVALUE = (int64_t) __stp_sign_extend32(val);
else
/* High bits may be garbage. */
STAP_RETVALUE = (int64_t) (val & 0xffffffff);
} else
STAP_RETVALUE = (int64_t) val;
return;
bad_argnum:
snprintf(CONTEXT->error_buffer, sizeof(CONTEXT->error_buffer),
"cannot access arg(%lld)", STAP_ARG_argnum);
CONTEXT->last_error = CONTEXT->error_buffer;
return;
deref_fault: /* branched to from kread() */
snprintf (CONTEXT->error_buffer, sizeof(CONTEXT->error_buffer),
"kernel fault at %#lx accessing arg(%lld)", val,
STAP_ARG_argnum);
CONTEXT->last_error = CONTEXT->error_buffer;
%}
function probing_32bit_app:long() %{ /* pure */
STAP_RETVALUE = (CONTEXT->user_mode_p && _stp_is_compat_task());
%}
function arch_bytes:long() %{ /* pure */
STAP_RETVALUE = sizeof(long);
%}
function uarch_bytes:long() {
assert(user_mode(), "requires user mode")
return probing_32bit_app() ? 4 : 8
}
/* Return the value of function arg #argnum (1=first arg) as a signed int. */
function int_arg:long (argnum:long) {
return _stp_arg2(argnum, 1, 1, 0)
}
/* Return the value of function arg #argnum (1=first arg) as an unsigned int. */
function uint_arg:long (argnum:long) {
return _stp_arg2(argnum, 0, 1, 0)
}
function long_arg:long (argnum:long) {
return _stp_arg2(argnum, 1, 0, 0)
}
function ulong_arg:long (argnum:long) {
return _stp_arg2(argnum, 0, 0, 0)
}
function longlong_arg:long (argnum:long) {
if (probing_32bit_app()) {
lowbits = _stp_arg2(argnum, 0, 1, 0)
highbits = _stp_arg2(argnum+1, 0, 1, 0)
return ((highbits << 32) | lowbits)
} else
return _stp_arg2(argnum, 0, 0, 1)
}
function ulonglong_arg:long (argnum:long) {
return longlong_arg(argnum)
}
function pointer_arg:long (argnum:long) {
return _stp_arg2(argnum, 0, 0, 0)
}
function s32_arg:long (argnum:long) {
return int_arg(argnum)
}
function u32_arg:long (argnum:long) {
return uint_arg(argnum)
}
function s64_arg:long (argnum:long) {
return longlong_arg(argnum)
}
function u64_arg:long (argnum:long) {
return ulonglong_arg(argnum)
}
function asmlinkage() %{ /* pure */ %}
function fastcall() %{ /* pure */ %}
function regparm(n:long) %{
if (CONTEXT->user_mode_p && _stp_is_compat_task()
&& (STAP_ARG_n < 0 || STAP_ARG_n > 3)) {
snprintf(CONTEXT->error_buffer, sizeof(CONTEXT->error_buffer),
"For -m32 programs, "
"regparm value must be in the range 0-3.");
CONTEXT->last_error = CONTEXT->error_buffer;
} else if (STAP_ARG_n < 0 || STAP_ARG_n > 6) {
snprintf(CONTEXT->error_buffer, sizeof(CONTEXT->error_buffer),
"For x86_64, regparm value must be in the range 0-6.");
CONTEXT->last_error = CONTEXT->error_buffer;
} else
CONTEXT->regparm = _STP_REGPARM | (int) STAP_ARG_n;
%}