forked from DFHack/df-structures
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disasm.lisp
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disasm.lisp
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(in-package :work)
(defun ctor-addresses (address size)
(with-bytes-for-ref (vector offset *memory* size address)
(loop for i from 0 below size by 4
for val = (parse-int vector (+ offset i) 4)
unless (member val '(0 #xFFFFFFFF))
collect val)))
(defun disasm-at-addr (address size)
(with-bytes-for-ref (vector offset *memory* size address)
(dolist (cmd (disassemble-all vector :start offset :end (+ offset size)
:base-address address :errorp nil))
(when cmd
(format t "~10X: ~A~%" (x86-instruction-address cmd) (x86-instruction-text cmd))))))
(defun get-function-addrs (name)
(mapcar #'start-address-of
(remove-if-not (lambda (x &aux (org (origin-of x)))
(or (typep org 'executable-region-plt-entry)
(typep org 'executable-region-function)))
(find-regions-by-name (executable-of *process*) name))))
(defun describe-function (addr)
(format nil "0x~X~@[ [~A]~]" addr
(awhen (find-region-by-address (executable-of *process*) addr)
(symbol-name-of it))))
(defun is-stack-var? (arg)
(when (x86-argument-matches? arg :base-reg :esp :index-reg nil)
(x86-argument-memory-displacement arg)))
(defun collect-ctor-globals (address)
(with-bytes-for-ref (vector offset *memory* 16 address)
(let ((globals nil)
(dtor-addr nil)
(obj-addr nil)
(ctors nil)
(atexit-addrs (get-function-addrs "__cxa_atexit")))
(labels ((is-atexit? (addr)
(member addr atexit-addrs)))
(disassemble-iter (cmd vector :start offset :base-address address :errorp nil)
(case (x86-instruction-mnemonic cmd)
(:ret (return))
(:call (let ((addr (x86-instruction-addr-value cmd)))
(if (is-atexit? addr)
(let ((cmstr (format nil "~{ctor ~A; ~}dtor ~A"
(mapcar #'describe-function ctors)
(describe-function dtor-addr))))
(when (and globals (null (size-of (first globals))))
(let ((size (- obj-addr (offset-of (first globals)))))
(when (> size 0)
(setf (size-of (first globals)) size))))
(when obj-addr
(push (make-instance 'global-object
:name (cl-linux-debug.data-info::get-$-field
(format nil "obj_~X" obj-addr))
:offset obj-addr
:comment (make-instance 'comment :content cmstr))
globals))
(setf dtor-addr nil obj-addr nil ctors nil))
(push addr ctors))))
(:mov (when (typep (x86-instruction-argument2 cmd) 'x86-argument-constant)
(case (is-stack-var? (x86-instruction-argument1 cmd))
(0 (setf dtor-addr (x86-instruction-immediate cmd)))
(4 (setf obj-addr (x86-instruction-immediate cmd))))))))
(nreverse globals)))))
(defun list-globals/linux ()
(let ((section (find-section-by-name (main-image-of (executable-of *process*)) ".ctors")))
(loop for addr in (ctor-addresses (start-address-of section) (length-of section))
nconc (collect-ctor-globals addr))))
(defun scan-linux-destructor (address)
(with-bytes-for-ref (vector offset *memory* 16 address)
(let* ((region (find-region-by-address (executable-of *process*) address))
(length nil)
(cur-cfa 4)
(push-depth 0)
(unwinds nil)
(reg-state nil)
(stack-top nil)
(del-one (get-function-addrs "_ZdlPv"))
(del-arr (get-function-addrs "_ZdaPv"))
(del-str (get-function-addrs "_ZNSsD1Ev")))
(when region
(setf vector (data-bytes-of region)
offset (start-offset-of region)
address (start-address-of region)
length (or (length-of region) length)
unwinds (region-unwind-table (origin-of region))))
(labels ((get-callee-name (addr)
(cond ((member addr del-one)
"delete")
((member addr del-arr)
"delete[]")
((member addr del-str)
"~string")
(t
(describe-function addr))))
(emit-call (cmd name)
(format t "~X: call ~A: ~A~%"
(x86-instruction-address cmd)
name stack-top))
(get-reg (reg)
(if reg
(or (assoc-value reg-state reg) "?")
nil))
(invalidate-reg (arg)
(when (and (typep arg 'x86-argument-register)
(x86-argument-access-write? arg))
(setf (assoc-value reg-state (x86-argument-register-id arg)) nil)))
(invalidate (cmd)
(invalidate-reg (x86-instruction-argument1 cmd))
(invalidate-reg (x86-instruction-argument2 cmd))))
(disassemble-iter (cmd vector
:start offset :base-address address
:end (if length (+ offset length))
:errorp nil)
(let ((opcode (x86-instruction-mnemonic cmd))
(arg1 (x86-instruction-argument1 cmd))
(arg2 (x86-instruction-argument2 cmd))
(addr (x86-instruction-addr-value cmd))
(imm (x86-instruction-immediate cmd)))
(case opcode
(:ret (return))
;; Track stack frame changes
(:push
(incf cur-cfa 4)
(incf push-depth))
(:pop
(decf cur-cfa 4)
(decf push-depth)
(setf stack-top nil)
(invalidate cmd))
((:sub :add)
(when (and (x86-argument-matches? arg1 :reg-id :esp)
(typep arg2 'x86-argument-constant))
(incf cur-cfa (if (eq opcode :sub) imm (- imm))))
(invalidate cmd))
;; Bail out on tail-call
(:jmp
(unless (and (<= address addr)
(or (and length (< (- addr address) length))
(= cur-cfa 4)))
(emit-call cmd (get-callee-name addr))
(return)))
;; Log calls
(:call
(emit-call cmd (get-callee-name addr)))
;; Save move and lea arithmetic
((:mov :lea)
(let ((val
(typecase arg2
(x86-argument-register
(get-reg (x86-argument-register-id arg2)))
(x86-argument-constant
(format nil "0x~X" imm))
(x86-argument-memory
(aif (is-stack-var? arg2)
(let ((unwind (when unwinds
(lookup-chunk unwinds (x86-instruction-address cmd)))))
(when (if unwind
(= it (unwind-state-cfa unwind))
(= it cur-cfa))
"this"))
(let* ((base (x86-argument-memory-base-reg arg2))
(disp (x86-argument-memory-displacement arg2))
(idx (x86-argument-memory-index-reg arg2))
(val
(cond (base
(format nil "~A~{+~A*~A~}~@[~A~]"
(get-reg base)
(when idx
(list (get-reg idx)
(x86-argument-memory-scale arg2)))
(when (/= disp 0)
(format-hex-offset disp :force-sign? t))))
(idx
(format nil "~@[~A+~]~A*~A~@[~A~]"
(get-reg base)
(get-reg idx) (x86-argument-memory-scale arg2)
(when (/= disp 0)
(format-hex-offset disp :force-sign? t))))
(t
(format-hex-offset disp)))))
(if (eq opcode :lea)
val
(concatenate 'string "[" val "]"))))))))
(acond ((is-stack-var? arg1)
(when (= it 0)
(setf stack-top val)))
((typep arg1 'x86-argument-register)
(setf (assoc-value reg-state (x86-argument-register-id arg1)) val)))))
;;
(otherwise (invalidate cmd)))))))))