01/03: gnu: qemu: Fix ioctl(…, SIOCGIFCONF, …) for emulated 64 bit architectures.

[guix-commits]

civodul pushed a commit to branch master
in repository guix.

commit 795db9d2199200e69d0acc7ffad4546a75679f95
Author: Stefan <stefan-guix@vodafonemail.de>
AuthorDate: Mon Jan 11 21:32:47 2021 +0100

    gnu: qemu: Fix ioctl(…, SIOCGIFCONF, …) for emulated 64 bit architectures.
    
    * gnu/packages/virtualization.scm (qemu): Add a snippet to fix a bug in the
    do_ioctl_ifconf() function of qemu to make ioctl(…, SIOCGIFCONF, …) work for
    emulated 64 bit architectures.
    
    The sizeof(struct ifreq) is 40 for 64 bit and 32 for 32 bit architectures.
    This structure contains a union of other structures, of which struct ifmap
    is the biggest for 64 bit architectures. Calling ioctl(…, SIOCGIFCONF, …)
    fills a struct sockaddr of that union, and do_ioctl_ifconf() only considered
    that struct sockaddr for the size of the union, which has the same size as
    struct ifmap on 32 bit architectures. So do_ioctl_ifconf() assumed a wrong
    size of 32 for struct ifreq instead of the correct size of 40 on 64 bit
    architectures.
    
    The fix makes do_ioctl_ifconf() handle struct ifmap as the biggest part of
    the union, treating struct ifreq with the correct size.
    
    This fixes (@ (guix build syscalls) network-interface-names) when used in
    emulated 64 bit architectures.
    
    Signed-off-by: Ludovic Courtès <ludo@gnu.org>
---
 gnu/packages/virtualization.scm | 29 ++++++++++++++++++++++-------
 1 file changed, 22 insertions(+), 7 deletions(-)

diff --git a/gnu/packages/virtualization.scm b/gnu/packages/virtualization.scm
index 77f8502..2262aa6 100644
--- a/gnu/packages/virtualization.scm
+++ b/gnu/packages/virtualization.scm
@@ -137,13 +137,28 @@
               (method url-fetch)
               (uri (string-append "https://download.qemu.org/qemu-";
                                   version ".tar.xz"))
-              (sha256
-               (base32
-                "1rd41wwlvp0vpialjp2czs6i3lsc338xc72l3zkbb7ixjfslw5y9"))
-              (patches (search-patches "qemu-build-info-manual.patch"))))
-    (outputs '("out" "doc"))            ;4.7 MiB of HTML docs
-    (build-system gnu-build-system)
-    (arguments
+               (sha256
+                (base32
+                 "1rd41wwlvp0vpialjp2czs6i3lsc338xc72l3zkbb7ixjfslw5y9"))
+              (patches (search-patches "qemu-build-info-manual.patch"))
+              (modules '((guix build utils)))
+              (snippet
+               '(begin
+                  ;; Fix a bug in the do_ioctl_ifconf() function of qemu to
+                  ;; make ioctl(…, SIOCGIFCONF, …) work for emulated 64 bit
+                  ;; architectures.  The size of struct ifreq is handled
+                  ;; incorrectly.
+                  ;; 
https://lists.nongnu.org/archive/html/qemu-devel/2021-01/msg01545.html
+                  (substitute* '("linux-user/syscall.c")
+                    (("^([[:blank:]]*)const argtype ifreq_arg_type.*$" line 
indent)
+                     (string-append line indent
+                                    "const argtype ifreq_max_type[] = { 
MK_STRUCT(STRUCT_ifmap_ifreq) };\n"))
+                    (("^([[:blank:]]*)target_ifreq_size[[:blank:]]=.*$" _ 
indent)
+                     (string-append indent "target_ifreq_size = 
thunk_type_size(ifreq_max_type, 0);")))
+                  #t))))
+     (outputs '("out" "doc"))            ;4.7 MiB of HTML docs
+     (build-system gnu-build-system)
+     (arguments
      `(;; FIXME: Disable tests on i686 to work around
        ;; <https://bugs.gnu.org/40527>.
        #:tests? ,(or (%current-target-system)