From 4949ada9da470b266063ff490438c85541af24cc Mon Sep 17 00:00:00 2001
From: David Thompson <dthompson2@worcester.edu>
Date: Sat, 1 Aug 2015 13:54:40 -0400
Subject: build: container: Setup /dev/console.

* gnu/build/linux-container.scm (mount-file-systems): Bind mount the
  controlling terminal as /dev/console.
---
 gnu/build/linux-container.scm | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

(limited to 'gnu/build/linux-container.scm')

diff --git a/gnu/build/linux-container.scm b/gnu/build/linux-container.scm
index af599040a1..c004303f03 100644
--- a/gnu/build/linux-container.scm
+++ b/gnu/build/linux-container.scm
@@ -55,6 +55,9 @@ to ROOT, then make ROOT the new root directory for the process."
   (define (scope dir)
     (string-append root dir))
 
+  (define (touch file-name)
+    (call-with-output-file file-name (const #t)))
+
   (define (bind-mount src dest)
     (mount src dest "none" MS_BIND))
 
@@ -89,8 +92,7 @@ to ROOT, then make ROOT the new root directory for the process."
   (for-each (lambda (device)
               (when (file-exists? device)
                 ;; Create the mount point file.
-                (call-with-output-file (scope device)
-                  (const #t))
+                (touch (scope device))
                 (bind-mount device (scope device))))
             '("/dev/null"
               "/dev/zero"
@@ -101,6 +103,15 @@ to ROOT, then make ROOT the new root directory for the process."
               "/dev/ptmx"
               "/dev/fuse"))
 
+  ;; Setup the container's /dev/console by bind mounting the pseudo-terminal
+  ;; associated with standard input.
+  (let ((in      (current-input-port))
+        (console (scope "/dev/console")))
+    (when (isatty? in)
+      (touch console)
+      (chmod console #o600)
+      (bind-mount (ttyname in) console)))
+
   ;; Setup standard input/output/error.
   (symlink "/proc/self/fd"   (scope "/dev/fd"))
   (symlink "/proc/self/fd/0" (scope "/dev/stdin"))
-- 
cgit 1.4.1


From ee78d02452208b3cfd971cd5533570a1d3523512 Mon Sep 17 00:00:00 2001
From: David Thompson <dthompson2@worcester.edu>
Date: Sat, 5 Sep 2015 14:10:08 -0400
Subject: build: container: Use the same clone flags as fork(3).

The intent is to make 'clone' behave a lot more like 'primitive-fork', which
calls clone(2) with SIGCHLD, CLONE_CHILD_CLEARTID, and CLONE_CHILD_SETTID
flags.  Notably, running 'clone' at the REPL without these flags would break
the REPL beyond repair.

* guix/build/syscalls.scm (CLONE_CHILD_CLEARTID, CLONE_CHILD_SETTID): New
  variables.
* gnu/build/linux-container.scm (namespaces->bit-mask): Add
  CLONE_CHILD_CLEARTID and CLONE_CHILD_SETTID to bit mask.
---
 gnu/build/linux-container.scm |  3 ++-
 guix/build/syscalls.scm       | 16 ++++++++++------
 2 files changed, 12 insertions(+), 7 deletions(-)

(limited to 'gnu/build/linux-container.scm')

diff --git a/gnu/build/linux-container.scm b/gnu/build/linux-container.scm
index c004303f03..95220d0bc0 100644
--- a/gnu/build/linux-container.scm
+++ b/gnu/build/linux-container.scm
@@ -162,7 +162,8 @@ host user identifiers to map into the user namespace."
 (define (namespaces->bit-mask namespaces)
   "Return the number suitable for the 'flags' argument of 'clone' that
 corresponds to the symbols in NAMESPACES."
-  (apply logior SIGCHLD
+  ;; Use the same flags as fork(3) in addition to the namespace flags.
+  (apply logior SIGCHLD CLONE_CHILD_CLEARTID CLONE_CHILD_SETTID
          (map (match-lambda
                ('mnt  CLONE_NEWNS)
                ('uts  CLONE_NEWUTS)
diff --git a/guix/build/syscalls.scm b/guix/build/syscalls.scm
index 093eb0a1a0..2c2fbde0a3 100644
--- a/guix/build/syscalls.scm
+++ b/guix/build/syscalls.scm
@@ -50,6 +50,8 @@
             mkdtemp!
             pivot-root
 
+            CLONE_CHILD_CLEARTID
+            CLONE_CHILD_SETTID
             CLONE_NEWNS
             CLONE_NEWUTS
             CLONE_NEWIPC
@@ -303,12 +305,14 @@ string TMPL and return its file name.  TMPL must end with 'XXXXXX'."
         (pointer->string result)))))
 
 ;; Linux clone flags, from linux/sched.h
-(define CLONE_NEWNS   #x00020000)
-(define CLONE_NEWUTS  #x04000000)
-(define CLONE_NEWIPC  #x08000000)
-(define CLONE_NEWUSER #x10000000)
-(define CLONE_NEWPID  #x20000000)
-(define CLONE_NEWNET  #x40000000)
+(define CLONE_CHILD_CLEARTID #x00200000)
+(define CLONE_CHILD_SETTID   #x01000000)
+(define CLONE_NEWNS          #x00020000)
+(define CLONE_NEWUTS         #x04000000)
+(define CLONE_NEWIPC         #x08000000)
+(define CLONE_NEWUSER        #x10000000)
+(define CLONE_NEWPID         #x20000000)
+(define CLONE_NEWNET         #x40000000)
 
 ;; The libc interface to sys_clone is not useful for Scheme programs, so the
 ;; low-level system call is wrapped instead.
-- 
cgit 1.4.1