suzanne.soy/racket
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

mach-o: fix problems related to code signing

Browse Source 
Strip any code signing when generating an executable from
Racket or GRacket. Also, place the __LINKEDIT segment in
virtual memory after the __PLTSCHEME segment, so that
the in-memory layout order matches the file layout order,
which in turn makes the code-signing tool's update of the
__LINKEDIT segment's size not create a virtual-memory
overlap with __PLTSCHEME.
This commit is contained in:
Matthew Flatt 2013-01-17 20:38:40 -06:00
parent a229f2924d
commit 1744a78738
1 changed files with 63 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

72
collects/compiler/private/mach-o.rkt
View File

@ -45,7 +45,7 @@
(read-ulong p)
(read-ulong p)
(check-same #x2 (read-ulong p))
(let* ([cnt (read-ulong p)]
(let* ([total-cnt (read-ulong p)]
[cmdssz (read-ulong p)]
[min-used (round-up-page cmdssz)]
[sym-tab-pos #f]
@ -62,12 +62,15 @@
[function-starts-pos #f]
[function-starts-offset #f]
[data-in-code-pos #f]
[data-in-code-offset #f])
[data-in-code-offset #f]
[code-signature-pos #f]
[code-signature-size 0]
[code-signature-lc-sz 0])
;; (printf "~a cmds, length 0x~x\n" cnt cmdssz)
(read-ulong p) ; flags
(when (equal? exe-id #xFeedFacf)
(read-ulong p)) ; extra reserved word for 64-bit header
(let loop ([cnt cnt])
(let loop ([cnt total-cnt])
(unless (zero? cnt)
(let ([pos (file-position p)]
[cmd (read-ulong p)]
@ -148,18 +151,39 @@
;; LC_DATA_IN_CODE
(set! data-in-code-offset (read-ulong p))
(set! data-in-code-pos pos)]
[(#x1D)
;; LC_CODE_SIGNATURE
(if (= cnt 1)
(let ([offset (read-ulong p)]
[size (read-ulong p)])
(file-position p (+ offset size))
(if (eof-object? (read-byte p))
(let ([extra (detect-linkedit-padding p
link-edit-offset
link-edit-len
offset
(if link-edit-64? 8 4))])
(set! code-signature-pos pos)
(set! code-signature-lc-sz sz)
(set! code-signature-size (+ size extra)))
(log-warning "WARNING: code signature is not at end of file")))
(log-warning "WARNING: code signature is not last load command"))]
[else
(void)])
(file-position p (+ pos sz))
(loop (sub1 cnt)))))
;; (printf "Start offset: 0x~x\n" min-used)
(let ([end-cmd (+ cmdssz (if (equal? exe-id #xFeedFacf) 32 28))]
(let ([end-cmd (+ cmdssz
(if (equal? exe-id #xFeedFacf) 32 28)
(- code-signature-lc-sz))]
[new-cmd-sz (if link-edit-64? 72 56)]
[outlen (round-up-page (bytes-length segdata))]
[out-offset (if move-link-edit?
link-edit-offset
(+ link-edit-offset (round-up-page link-edit-len)))]
[out-addr (+ link-edit-addr (round-up-page link-edit-vmlen))])
[out-addr (if move-link-edit?
link-edit-addr
(+ link-edit-addr (round-up-page link-edit-vmlen)))])
(unless ((+ end-cmd new-cmd-sz) . < . min-used)
(error 'check-header
"no room for a new section load command (current end is ~a; min used is ~a)"
@ -172,8 +196,8 @@
(display s out))
(file-position out 16)
;; Increment the number of load commands:
(write-ulong (+ cnt 1) out)
(write-ulong (+ cmdssz new-cmd-sz) out)
(write-ulong (+ total-cnt 1 (if code-signature-pos -1 0)) out)
(write-ulong (+ cmdssz (- code-signature-lc-sz) new-cmd-sz) out)
;; Write the new command:
(file-position out link-edit-pos)
(write-ulong (if link-edit-64? #x19 1) out) ; LC_SEGMENT[_64]
@ -208,12 +232,15 @@
(set! link-edit-pos (+ link-edit-pos new-cmd-sz))
(when move-link-edit?
;; Update link-edit segment entry:
(file-position out (+ link-edit-pos (if link-edit-64? 40 32)))
(file-position out (+ link-edit-pos 24))
((if link-edit-64? write-xulong write-ulong) (+ link-edit-addr outlen) out)
((if link-edit-64? write-xulong write-ulong) link-edit-vmlen out)
;; (printf "Update to ~a\n" (+ out-offset outlen))
((if link-edit-64? write-xulong write-ulong) (+ out-offset outlen) out)
((if link-edit-64? write-xulong write-ulong) (- link-edit-len code-signature-size) out)
;; Read link-edit segment:
(file-position p link-edit-offset)
(let ([link-edit (read-bytes link-edit-len p)])
(let ([link-edit (read-bytes (- link-edit-len code-signature-size) p)])
;; Write link-edit data in new location:
(file-position out (+ link-edit-offset outlen))
(display link-edit out))
@ -263,12 +290,39 @@
(file-position out out-offset)
(display segdata out)
(display (make-bytes (- outlen (bytes-length segdata)) 0) out)
(file-truncate out (+ link-edit-offset link-edit-len (- code-signature-size) outlen))
;; Result is offset where data was written:
out-offset)))
(lambda ()
(close-input-port p)
(close-output-port out)))))
(define (detect-linkedit-padding p offset size lc-offset alignment)
;; To add a code signature, link-edit size may have been rounded up
;; to a multiple of 16. Look for extra \0s before the code-signature
;; offset.
(unless (zero? (modulo size 16))
(error 'detect-linkedit-padding "expected a multiple of 16 for current size"))
(define orig-pos (file-position p))
(file-position p (- lc-offset 16))
(define bstr (read-bytes 16 p))
(file-position p orig-pos)
(if (= alignment 8)
(if (regexp-match? #px#"\0{9}$" bstr)
8 ; must be an extra word
0)
(cond
[(regexp-match? #px#"\0{14}$" bstr)
;; three extra words
12]
[(regexp-match? #px#"\0{10}$" bstr)
;; two extra words
8]
[(regexp-match? #px#"\0{6}$" bstr)
;; an extra word
4]
[else 0])))
(define (fix-offset p pos out d base delta)
(when (and out (not (zero? delta)))
(file-position p (+ pos d))