;++
;
; Copyright (c) 1991 Microsoft Corporation
;
; Module Name:
;
; ntnap.asm
;
; Abstract:
;
; This module implements the system service dispatch procedure.
; It also creates a "profile" of each service by counting and
; timing calls.
;
; Author:
;
; Russ Blake (russbl) 22-Apr-1991
;
; Environment:
;
; User or kernel mode.
;
; Revision History:
;
;--
include ks386.inc
include callconv.inc ; calling convention macros
include mac386.inc
include ntnap.inc
.386
EXTRN _NapDllInit:near
EXTRN _NapRecordInfo:near
NapStart equ [ebp - 08h]
NapEnd equ [ebp - 010h]
NapServiceNum equ [ebp - 014h]
NapLocalSize equ 4 * 5
NapCalSrvNum equ 0FFFFFFFFh
;++
;
; Routine Description:
;
; This routine is called to save registers during API profiling.
; The objecttive is to preserve the caller's environment
; while timing takes place and, once, while dll initialization
; takes place. This routine svaes registers on the stack to
; permit recursivce calls.
;
; There should be a matching call to NapRestoreRegs to restore
; the registers.
;
; Arguments:
;
; All registers.
;
; Return Value:
;
; None. All registers are preserved on the stack.
;
;--
.386p
_TEXT SEGMENT DWORD USE32 PUBLIC 'CODE'
ASSUME CS:FLAT, DS:FLAT, ES:FLAT, SS:NOTHING, FS:NOTHING, GS:NOTHING
cPublicProc _NapSaveRegs
;
; This is how the stack looks like upon entering this routine:
;
; ---+----+----+----+----+----
; | Return Address |
; ---+----+----+----+----+----
; esp+ esp+
; 0 4
;
;
; -> popping makes esp go ->
; <- pushing makes esp go <-
;
push ebp
mov ebp,esp ; Remember where we are during this stuff
; ebp = Original esp - 4
push eax
push ebx
push ecx
push edx
push esi
push edi
pushfd
push ds
push es
push ss
push fs
push gs
mov eax,[ebp+4] ; Grab Return Address
push eax ; Put Return Address on Stack
mov ebp,[ebp+0] ; Restore original ebp
;
; This is how the stack looks like just before executing RET:
;
;
; +----+----+----+----+----+----+----+----+----+----+----+----+
; | Return Address | g s | f s |
; +----+----+----+----+----+----+----+----+----+----+----+----+
; esp+
; 0
;
; +----+----+----+----+----+----+----+----+----+----+----+----+
; | s s | e s | d s |
; +----+----+----+----+----+----+----+----+----+----+----+----+
; esp+
; c
;
; +----+----+----+----+----+----+----+----+----+----+----+----+
; | eflags | edi | esi |
; +----+----+----+----+----+----+----+----+----+----+----+----+
; +----+----+----+----+----+----+----+----+----+----+----+----+
; | edx | ecx | ebx |
; +----+----+----+----+----+----+----+----+----+----+----+----+
; +----+----+----+----+----+----+----+----+----+----+----+----+----
; | eax | original ebp | Return Address |
; +----+----+----+----+----+----+----+----+----+----+----+----+----
; was
; ebp+
; 0
;
stdRET _NapSaveRegs
stdENDP _NapSaveRegs
cPublicProc _NapRestoreRegs,,near
;
; This is how the stack looks like upon entering this routine:
;
;
; +----+----+----+----+----+----+----+----+----+----+----+----+
; | Return Address | g s | f s |
; +----+----+----+----+----+----+----+----+----+----+----+----+
; esp+
; 0
;
; +----+----+----+----+----+----+----+----+----+----+----+----+
; | s s | e s | d s |
; +----+----+----+----+----+----+----+----+----+----+----+----+
; esp+
; c
;
; +----+----+----+----+----+----+----+----+----+----+----+----+
; | eflags | edi | esi |
; +----+----+----+----+----+----+----+----+----+----+----+----+
; esp+
; 18
;
; +----+----+----+----+----+----+----+----+----+----+----+----+
; | edx | ecx | ebx |
; +----+----+----+----+----+----+----+----+----+----+----+----+
; esp+
; 24
;
; +----+----+----+----+----+----+----+----+----+----+----+----+----
; | eax | original ebp | Return Address |
; +----+----+----+----+----+----+----+----+----+----+----+----+----
; esp+ esp+ esp+
; 30 34 38
;
pop eax ; Get Return Address
push ebp ; Save a temporary copy of original BP
mov ebp,esp ; BP = Original SP + 4
mov [ebp+038h],eax ; Put Return Address on Stack
pop eax ; Get Original BP
mov [ebp+034h],eax ; Put it in the original BP place
pop gs
pop fs
pop ss
pop es
pop ds
popfd
pop edi
pop esi
pop edx
pop ecx
pop ebx
pop eax
pop ebp
stdRET _NapRestoreRegs
stdENDP _NapRestoreRegs
;++
;
; Routine Description:
;
; This routine is called by the initialization code in the
; Nt Api Profiler to calibrate the cost of profiling.
; It simulates the overhead of a profiled call to a system
; service, but carefully avoids doing any of the normal
; work associated with such a call.
;
; NOTE: This routine's code should exactly parallel that of
; _NapDispatch, except for any operation normally
; (i.e., when not profiling) executed to call a system service.
; This amounts to an "int 2Eh" in the middle of the routine.
;
; Arguments:
;
; eax - Service Number of the routine being called. Must be -1
; for all calls to this routine. The routine
; _NapRecordInfo notes this value and discards
; the call.
;
; edx - Pointer to the parameters to the Service; ignored by
; this routine.
;
; Return Value:
;
; None.
;
;--
cPublicProc _NapCalibrate , ,near
push ebp ; Locals: the value of
mov ebp, esp ; the perf counter before and
sub esp, NapLocalSize ; after the API call
mov eax, NapCalSrvNum ; special routine number
mov NapServicenum, eax ; is used for calibration
; can't be passed in eax from
; C routine, so load it here
; save the service routine number
stdCall _NapSaveRegs ; save register state so call to
; get counter does not destroy them
stdCall _NapDllInit ; initialize dll if necessary
; Now call NtQueryPerformanceCounter to get the starting count;
; Store this locally
push 0 ; don't need frequency: pass 0
lea eax, NapStart ; (eax) = pointer to counter
push eax ; pass pointer to counter
mov eax, NapCounterServiceNumber
lea edx, [esp] ; (edx) -> arguments
int 2Eh ; get the current counter value
add esp, 08h ; remove counter parameters
; Restore caller's registers
stdCall _NapRestoreRegs
; We're just calibrating the overhead, so we don't call the system
; service here.
; Save regsiters so we can complete the profile accounting.
stdCall _NapSaveRegs
; Now get the ending counter.
push 0 ; don't need frequency: pass 0
lea eax, NapEnd ; (eax) = pointer to counter
push eax ; pass pointer to counter
mov eax, NapCounterServiceNumber
lea edx, [esp] ; (edx) -> arguments
int 2Eh ; get the current counter value
add esp, 08h ; remove counter parameters
; Compute the time for this call and increment the nukmber of calls.
lea eax, NapEnd ; pointer to start/end counters
; ID of this routine
stdCall _NapRecordInfo, <NapServiceNum, eax>
stdCall _NapRestoreRegs
; restore caller's registers
leave ; we needed this for pseudo locals
stdRET _NapCalibrate
stdENDP _NapCalibrate
;++
;
; Routine Description:
;
; This routine is called by the USRSTUBS_ENTRY1 MACRO in the
; services.prf to carry out profiling on an Nt system api call.
;
; Arguments:
;
; eax - Service Number of the routine being called. This number
; is assigned by genprof.c from the table in services.tab.
;
; edx - Pointer to the parameters to the Service.
;
; Return Value:
;
; Whatever the system service returns.
;
;--
cPublicProc _NapProfileDispatch , ,near
push ebp ; Locals: the value of
mov ebp, esp ; the perf counter before and
sub esp, NapLocalSize ; after the API call
mov NapServicenum, eax
; save the service routine number
stdCall _NapSaveRegs ; save register state so call to
; get counter does not destroy them
stdCall _NapDllInit ; initialize dll if necessary
; Now call NtQueryPerformanceCounter to get the starting count;
; Store this locally
push 0 ; don't need frequency: pass 0
lea eax, NapStart ; (eax) = pointer to counter
push eax ; pass pointer to counter
mov eax, NapCounterServiceNumber
lea edx, [esp] ; (edx) -> arguments
int 2Eh ; get the current counter value
add esp, 08h ; remove counter parameters
; Restore caller's registers
stdCall _NapRestoreRegs
INT 2Eh ; invoke system service
; Save regsiters so we can complete the profile accounting.
stdCall _NapSaveRegs
; Now get the ending counter.
push 0 ; don't need frequency: pass 0
lea eax, NapEnd ; (eax) = pointer to counter
push eax ; pass pointer to counter
mov eax, NapCounterServiceNumber
lea edx, [esp] ; (edx) -> arguments
int 2Eh ; get the current counter value
add esp, 08h ; remove counter parameters
; Compute the time for this call and increment the number of calls.
lea eax, NapEnd ; pointer to start/end counters
; ID of this routine
stdCall _NapRecordInfo, <NapServiceNum, eax>
stdCall _NapRestoreRegs
; restore caller's registers
leave ; we needed this for pseudo locals
stdRET _NapProfileDispatch
stdENDP _NapProfileDispatch
;++
;
; Routine Description:
;
; This routine is claled to get the spin lock associated with
; a particular api. It prevents the simultaneous update
; from multiple threads in this or other processors of the
; profiling data for the api.
;
; Arguments:
;
; SpinLockAddr - address of the spin lock within the data
; for the api being updated.
;
; Return Value:
;
; None.
;
;--
cPublicProc _NapAcquireSpinLock , ,near
push eax
mov eax, [esp+8] ; get address of lock
WaitForLock:
lock bts dword ptr [eax], 0 ; test and set the spinlock
jc SHORT WaitForLock ; spinlock owned: go to SpinLabel
pop eax
stdRET _NapAcquireSpinLock
stdENDP _NapAcquireSpinLock
;++
;
; Routine Description:
;
; This routine is called to release the spin lock associated with
; a particular api.
;
; Arguments:
;
; SpinLockAddr - address of the spin lock within the data
; for the api being updated.
;
; Return Value:
;
; None.
;
;--
cPublicProc _NapReleaseSpinLock , ,near
push eax
mov eax, [esp+8] ; get address of lock
lock btr dword ptr [eax], 0 ; release spinlock
pop eax
stdRET _NapReleaseSpinLock
stdENDP _NapReleaseSpinLock
_TEXT ends
end