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-rw-r--r--Makefile.am2
-rw-r--r--guix/build/gremlin.scm236
-rw-r--r--tests/gremlin.scm57
3 files changed, 295 insertions, 0 deletions
diff --git a/Makefile.am b/Makefile.am
index 4a1f8d0a88..cf709986ed 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -82,6 +82,7 @@ MODULES = \
guix/build/cvs.scm \
guix/build/svn.scm \
guix/build/syscalls.scm \
+ guix/build/gremlin.scm \
guix/build/emacs-utils.scm \
guix/build/graft.scm \
guix/packages.scm \
@@ -178,6 +179,7 @@ SCM_TESTS = \
tests/union.scm \
tests/profiles.scm \
tests/syscalls.scm \
+ tests/gremlin.scm \
tests/lint.scm
if HAVE_GUILE_JSON
diff --git a/guix/build/gremlin.scm b/guix/build/gremlin.scm
new file mode 100644
index 0000000000..e8429129e1
--- /dev/null
+++ b/guix/build/gremlin.scm
@@ -0,0 +1,236 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2015 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (guix build gremlin)
+ #:use-module (guix elf)
+ #:use-module (ice-9 match)
+ #:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-9)
+ #:use-module (srfi srfi-26)
+ #:use-module (system foreign)
+ #:use-module (rnrs bytevectors)
+ #:use-module (rnrs io ports)
+ #:export (elf-dynamic-info
+ elf-dynamic-info?
+ elf-dynamic-info-sopath
+ elf-dynamic-info-needed
+ elf-dynamic-info-rpath
+ elf-dynamic-info-runpath
+
+ validate-needed-in-runpath))
+
+;;; Commentary:
+;;;
+;;; A gremlin is sort-of like an elf, you know, and this module provides tools
+;;; to deal with dynamic-link information from ELF files.
+;;;
+;;; Code:
+
+(define (dynamic-link-segment elf)
+ "Return the 'PT_DYNAMIC' segment of ELF--i.e., the segment that contains
+dynamic linking information."
+ (find (lambda (segment)
+ (= (elf-segment-type segment) PT_DYNAMIC))
+ (elf-segments elf)))
+
+(define (word-reader size byte-order)
+ "Return a procedure to read a word of SIZE bytes according to BYTE-ORDER."
+ (case size
+ ((8)
+ (lambda (bv index)
+ (bytevector-u64-ref bv index byte-order)))
+ ((4)
+ (lambda (bv index)
+ (bytevector-u32-ref bv index byte-order)))))
+
+
+;; Dynamic entry:
+;;
+;; typedef struct
+;; {
+;; Elf64_Sxword d_tag; /* Dynamic entry type */
+;; union
+;; {
+;; Elf64_Xword d_val; /* Integer value */
+;; Elf64_Addr d_ptr; /* Address value */
+;; } d_un;
+;; } Elf64_Dyn;
+
+(define (raw-dynamic-entries elf segment)
+ "Return as a list of type/value pairs all the dynamic entries found in
+SEGMENT, the 'PT_DYNAMIC' segment of ELF. In the result, each car is a DT_
+value, and the interpretation of the cdr depends on the type."
+ (define start
+ (elf-segment-offset segment))
+ (define bytes
+ (elf-bytes elf))
+ (define word-size
+ (elf-word-size elf))
+ (define byte-order
+ (elf-byte-order elf))
+ (define read-word
+ (word-reader word-size byte-order))
+
+ (let loop ((offset 0)
+ (result '()))
+ (if (>= offset (elf-segment-memsz segment))
+ (reverse result)
+ (let ((type (read-word bytes (+ start offset)))
+ (value (read-word bytes (+ start offset word-size))))
+ (if (= type DT_NULL) ;finished?
+ (reverse result)
+ (loop (+ offset (* 2 word-size))
+ (alist-cons type value result)))))))
+
+(define (vma->offset elf vma)
+ "Convert VMA, a virtual memory address, to an offset within ELF.
+
+Do that by looking at the loadable program segment (PT_LOAD) of ELF that
+contains VMA and by taking into account that segment's virtual address and
+offset."
+ ;; See 'offset_from_vma' in Binutils.
+ (define loads
+ (filter (lambda (segment)
+ (= (elf-segment-type segment) PT_LOAD))
+ (elf-segments elf)))
+
+ (let ((load (find (lambda (segment)
+ (let ((vaddr (elf-segment-vaddr segment)))
+ (and (>= vma vaddr)
+ (< vma (+ (elf-segment-memsz segment)
+ vaddr)))))
+ loads)))
+ (+ (- vma (elf-segment-vaddr load))
+ (elf-segment-offset load))))
+
+(define (dynamic-entries elf segment)
+ "Return all the dynamic entries found in SEGMENT, the 'PT_DYNAMIC' segment
+of ELF, as a list of type/value pairs. The type is a DT_ value, and the value
+may be a string or an integer depending on the entry type (for instance, the
+value of DT_NEEDED entries is a string.)"
+ (define entries
+ (raw-dynamic-entries elf segment))
+
+ (define string-table-offset
+ (any (match-lambda
+ ((type . value)
+ (and (= type DT_STRTAB) value))
+ (_ #f))
+ entries))
+
+ (define (interpret-dynamic-entry type value)
+ (cond ((memv type (list DT_NEEDED DT_SONAME DT_RPATH DT_RUNPATH))
+ (if string-table-offset
+ (pointer->string
+ (bytevector->pointer (elf-bytes elf)
+ (vma->offset
+ elf
+ (+ string-table-offset value))))
+ value))
+ (else
+ value)))
+
+ (map (match-lambda
+ ((type . value)
+ (cons type (interpret-dynamic-entry type value))))
+ entries))
+
+
+;;;
+;;; High-level interface.
+;;;
+
+(define-record-type <elf-dynamic-info>
+ (%elf-dynamic-info soname needed rpath runpath)
+ elf-dynamic-info?
+ (soname elf-dynamic-info-soname)
+ (needed elf-dynamic-info-needed)
+ (rpath elf-dynamic-info-rpath)
+ (runpath elf-dynamic-info-runpath))
+
+(define search-path->list
+ (let ((not-colon (char-set-complement (char-set #\:))))
+ (lambda (str)
+ "Split STR on ':' characters."
+ (string-tokenize str not-colon))))
+
+(define (elf-dynamic-info elf)
+ "Return dynamic-link information for ELF as an <elf-dynamic-info> object, or
+#f if ELF lacks dynamic-link information."
+ (match (dynamic-link-segment elf)
+ (#f #f)
+ ((? elf-segment? dynamic)
+ (let ((entries (dynamic-entries elf dynamic)))
+ (%elf-dynamic-info (assv-ref entries DT_SONAME)
+ (filter-map (match-lambda
+ ((type . value)
+ (and (= type DT_NEEDED) value))
+ (_ #f))
+ entries)
+ (or (and=> (assv-ref entries DT_RPATH)
+ search-path->list)
+ '())
+ (or (and=> (assv-ref entries DT_RUNPATH)
+ search-path->list)
+ '()))))))
+
+(define %libc-libraries
+ ;; List of libraries as of glibc 2.21 (there are more but those are
+ ;; typically mean to be LD_PRELOADed and thus do not appear as NEEDED.)
+ '("libanl.so"
+ "libcrypt.so"
+ "libc.so"
+ "libdl.so"
+ "libm.so"
+ "libpthread.so"
+ "libresolv.so"
+ "librt.so"
+ "libutil.so"))
+
+(define (libc-library? lib)
+ "Return #t if LIB is one of the libraries shipped with the GNU C Library."
+ (find (lambda (libc-lib)
+ (string-prefix? libc-lib lib))
+ %libc-libraries))
+
+(define* (validate-needed-in-runpath file
+ #:key (always-found? libc-library?))
+ "Return #t if all the libraries listed as FILE's 'DT_NEEDED' entries are
+present in its RUNPATH, or if FILE lacks dynamic-link information. Return #f
+otherwise. Libraries whose name matches ALWAYS-FOUND? are considered to be
+always available."
+ (let* ((elf (call-with-input-file file
+ (compose parse-elf get-bytevector-all)))
+ (dyninfo (elf-dynamic-info elf)))
+ (when dyninfo
+ (let* ((runpath (elf-dynamic-info-runpath dyninfo))
+ (needed (remove always-found?
+ (elf-dynamic-info-needed dyninfo)))
+ (not-found (remove (cut search-path runpath <>)
+ needed)))
+ (for-each (lambda (lib)
+ (format (current-error-port)
+ "error: '~a' depends on '~a', which cannot \
+be found in RUNPATH ~s~%"
+ file lib runpath))
+ not-found)
+ ;; (when (null? not-found)
+ ;; (format (current-error-port) "~a is OK~%" file))
+ (null? not-found)))))
+
+;;; gremlin.scm ends here
diff --git a/tests/gremlin.scm b/tests/gremlin.scm
new file mode 100644
index 0000000000..225a72ff9f
--- /dev/null
+++ b/tests/gremlin.scm
@@ -0,0 +1,57 @@
+;;; GNU Guix --- Functional package management for GNU
+;;; Copyright © 2015 Ludovic Courtès <ludo@gnu.org>
+;;;
+;;; This file is part of GNU Guix.
+;;;
+;;; GNU Guix is free software; you can redistribute it and/or modify it
+;;; under the terms of the GNU General Public License as published by
+;;; the Free Software Foundation; either version 3 of the License, or (at
+;;; your option) any later version.
+;;;
+;;; GNU Guix is distributed in the hope that it will be useful, but
+;;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;;; GNU General Public License for more details.
+;;;
+;;; You should have received a copy of the GNU General Public License
+;;; along with GNU Guix. If not, see <http://www.gnu.org/licenses/>.
+
+(define-module (test-gremlin)
+ #:use-module (guix elf)
+ #:use-module (guix build utils)
+ #:use-module (guix build gremlin)
+ #:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-64)
+ #:use-module (rnrs io ports)
+ #:use-module (ice-9 match))
+
+(define %guile-executable
+ (match (command-line)
+ ((program . _)
+ (and (file-exists? program) (elf-file? program)
+ program))
+ (_
+ #f)))
+
+(define read-elf
+ (compose parse-elf get-bytevector-all))
+
+
+(test-begin "gremlin")
+
+(unless %guile-executable (test-skip 1))
+(test-assert "elf-dynamic-info-needed, executable"
+ (let* ((elf (call-with-input-file %guile-executable read-elf))
+ (dyninfo (elf-dynamic-info elf)))
+ (or (not dyninfo) ;static executable
+ (lset<= string=?
+ (list (string-append "libguile-" (effective-version))
+ "libgc" "libunistring" "libffi")
+ (map (lambda (lib)
+ (string-take lib (string-contains lib ".so")))
+ (elf-dynamic-info-needed dyninfo))))))
+
+(test-end "gremlin")
+
+
+(exit (= (test-runner-fail-count (test-runner-current)) 0))
generated by cgit v1.2.3 (git 2.45.0) at 2024-11-15 10:13:57 +0000