diff options
author | Don Dugger <donald.d.dugger@intel.com> | 2015-10-29 22:15:25 +0000 |
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committer | Gerrit Code Review <gerrit@172.30.200.206> | 2015-10-29 22:15:25 +0000 |
commit | afc76d554ed517e38d46b6b182a7016406a1323f (patch) | |
tree | 06133cb33a43488837ea67667458e1582f2f40ce /kernel/kernel/fork.c | |
parent | 41f827bfbb10e03c4d228fbcc801dd51fb9983b0 (diff) | |
parent | ec0a2ed6d8a5e555edef907895c041e285fdb495 (diff) |
Merge "These changes are a raw update to a vanilla kernel 4.1.10, with the recently announced rt patch patch-4.1.10-rt10.patch. No further changes needed."
Diffstat (limited to 'kernel/kernel/fork.c')
-rw-r--r-- | kernel/kernel/fork.c | 28 |
1 files changed, 18 insertions, 10 deletions
diff --git a/kernel/kernel/fork.c b/kernel/kernel/fork.c index dd407cea0..1b0e656f6 100644 --- a/kernel/kernel/fork.c +++ b/kernel/kernel/fork.c @@ -1888,13 +1888,21 @@ static int check_unshare_flags(unsigned long unshare_flags) CLONE_NEWUSER|CLONE_NEWPID)) return -EINVAL; /* - * Not implemented, but pretend it works if there is nothing to - * unshare. Note that unsharing CLONE_THREAD or CLONE_SIGHAND - * needs to unshare vm. + * Not implemented, but pretend it works if there is nothing + * to unshare. Note that unsharing the address space or the + * signal handlers also need to unshare the signal queues (aka + * CLONE_THREAD). */ if (unshare_flags & (CLONE_THREAD | CLONE_SIGHAND | CLONE_VM)) { - /* FIXME: get_task_mm() increments ->mm_users */ - if (atomic_read(¤t->mm->mm_users) > 1) + if (!thread_group_empty(current)) + return -EINVAL; + } + if (unshare_flags & (CLONE_SIGHAND | CLONE_VM)) { + if (atomic_read(¤t->sighand->count) > 1) + return -EINVAL; + } + if (unshare_flags & CLONE_VM) { + if (!current_is_single_threaded()) return -EINVAL; } @@ -1963,16 +1971,16 @@ SYSCALL_DEFINE1(unshare, unsigned long, unshare_flags) if (unshare_flags & CLONE_NEWUSER) unshare_flags |= CLONE_THREAD | CLONE_FS; /* - * If unsharing a thread from a thread group, must also unshare vm. - */ - if (unshare_flags & CLONE_THREAD) - unshare_flags |= CLONE_VM; - /* * If unsharing vm, must also unshare signal handlers. */ if (unshare_flags & CLONE_VM) unshare_flags |= CLONE_SIGHAND; /* + * If unsharing a signal handlers, must also unshare the signal queues. + */ + if (unshare_flags & CLONE_SIGHAND) + unshare_flags |= CLONE_THREAD; + /* * If unsharing namespace, must also unshare filesystem information. */ if (unshare_flags & CLONE_NEWNS) |