From: Serge Hallyn Date: Mon, 2 Oct 2006 09:18:18 +0000 (-0700) Subject: [PATCH] uts: copy nsproxy only when needed X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=c0b2fc316599d6cd875b6b8cafa67f03b9512b4d;p=GitHub%2Fexynos8895%2Fandroid_kernel_samsung_universal8895.git [PATCH] uts: copy nsproxy only when needed The nsproxy was being copied in unshare() when anything was being unshared, even if it was something not referenced from nsproxy. This should end up in some cases with far more memory usage than necessary. Signed-off-by: Serge Hallyn Cc: Kirill Korotaev Cc: "Eric W. Biederman" Cc: Herbert Poetzl Cc: Andrey Savochkin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/kernel/fork.c b/kernel/fork.c index c08cf05dd59b..208dd99f13bc 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1606,7 +1606,7 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) struct mm_struct *mm, *new_mm = NULL, *active_mm = NULL; struct files_struct *fd, *new_fd = NULL; struct sem_undo_list *new_ulist = NULL; - struct nsproxy *new_nsproxy, *old_nsproxy; + struct nsproxy *new_nsproxy = NULL, *old_nsproxy = NULL; struct uts_namespace *uts, *new_uts = NULL; check_unshare_flags(&unshare_flags); @@ -1634,18 +1634,24 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) if ((err = unshare_utsname(unshare_flags, &new_uts))) goto bad_unshare_cleanup_semundo; - if (new_fs || new_ns || new_sigh || new_mm || new_fd || new_ulist || - new_uts) { - + if (new_ns || new_uts) { old_nsproxy = current->nsproxy; new_nsproxy = dup_namespaces(old_nsproxy); if (!new_nsproxy) { err = -ENOMEM; goto bad_unshare_cleanup_uts; } + } + + if (new_fs || new_ns || new_sigh || new_mm || new_fd || new_ulist || + new_uts) { task_lock(current); - current->nsproxy = new_nsproxy; + + if (new_nsproxy) { + current->nsproxy = new_nsproxy; + new_nsproxy = old_nsproxy; + } if (new_fs) { fs = current->fs; @@ -1687,9 +1693,11 @@ asmlinkage long sys_unshare(unsigned long unshare_flags) } task_unlock(current); - put_nsproxy(old_nsproxy); } + if (new_nsproxy) + put_nsproxy(new_nsproxy); + bad_unshare_cleanup_uts: if (new_uts) put_uts_ns(new_uts);