user/sven/linux.git/kernel/fork.c, branch v2.6.26.8

[PATCH] dup_fd() fixes, part 1

2008-05-16T21:22:26Z

Move the sucker to fs/file.c in preparation to the rest Signed-off-by: Al Viro

[PATCH] split linux/file.h

2008-05-01T17:08:16Z

Initial splitoff of the low-level stuff; taken to fdtable.h Signed-off-by: Al Viro

signals: microoptimize the usage of ->curr_target

2008-04-30T15:29:35Z

Suggested by Roland McGrath. Initialize signal->curr_target in copy_signal(). This way ->curr_target is never == NULL, we can kill the check in __group_complete_signal's hot path. Signed-off-by: Oleg Nesterov Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

procfs task exe symlink

2008-04-29T15:06:17Z

The kernel implements readlink of /proc/pid/exe by getting the file from the first executable VMA. Then the path to the file is reconstructed and reported as the result. Because of the VMA walk the code is slightly different on nommu systems. This patch avoids separate /proc/pid/exe code on nommu systems. Instead of walking the VMAs to find the first executable file-backed VMA we store a reference to the exec'd file in the mm_struct. That reference would prevent the filesystem holding the executable file from being unmounted even after unmapping the VMAs. So we track the number of VM_EXECUTABLE VMAs and drop the new reference when the last one is unmapped. This avoids pinning the mounted filesystem. [akpm@linux-foundation.org: improve comments] [yamamoto@valinux.co.jp: fix dup_mmap] Signed-off-by: Matt Helsley Cc: Oleg Nesterov Cc: David Howells Cc:"Eric W. Biederman" Cc: Christoph Hellwig Cc: Al Viro Cc: Hugh Dickins Signed-off-by: YAMAMOTO Takashi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: sysvsem: force unshare(CLONE_SYSVSEM) when CLONE_NEWIPC

2008-04-29T15:06:14Z

sys_unshare(CLONE_NEWIPC) doesn't handle the undo lists properly, this can cause a kernel memory corruption. CLONE_NEWIPC must detach from the existing undo lists. Fix, part 2: perform an implicit CLONE_SYSVSEM in CLONE_NEWIPC. CLONE_NEWIPC creates a new IPC namespace, the task cannot access the existing semaphore arrays after the unshare syscall. Thus the task can/must detach from the existing undo list entries, too. This fixes the kernel corruption, because it makes it impossible that undo records from two different namespaces are in sysvsem.undo_list. Signed-off-by: Manfred Spraul Signed-off-by: Serge E. Hallyn Acked-by: "Eric W. Biederman" Cc: Pavel Emelyanov Cc: Michael Kerrisk Cc: Pierre Peiffer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

ipc: sysvsem: implement sys_unshare(CLONE_SYSVSEM)

2008-04-29T15:06:14Z

sys_unshare(CLONE_NEWIPC) doesn't handle the undo lists properly, this can cause a kernel memory corruption. CLONE_NEWIPC must detach from the existing undo lists. Fix, part 1: add support for sys_unshare(CLONE_SYSVSEM) The original reason to not support it was the potential (inevitable?) confusion due to the fact that sys_unshare(CLONE_SYSVSEM) has the inverse meaning of clone(CLONE_SYSVSEM). Our two most reasonable options then appear to be (1) fully support CLONE_SYSVSEM, or (2) continue to refuse explicit CLONE_SYSVSEM, but always do it anyway on unshare(CLONE_SYSVSEM). This patch does (1). Changelog: Apr 16: SEH: switch to Manfred's alternative patch which removes the unshare_semundo() function which always refused CLONE_SYSVSEM. Signed-off-by: Manfred Spraul Signed-off-by: Serge E. Hallyn Acked-by: "Eric W. Biederman" Cc: Pavel Emelyanov Cc: Michael Kerrisk Cc: Pierre Peiffer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

cgroups: add an owner to the mm_struct

2008-04-29T15:06:10Z

Remove the mem_cgroup member from mm_struct and instead adds an owner. This approach was suggested by Paul Menage. The advantage of this approach is that, once the mm->owner is known, using the subsystem id, the cgroup can be determined. It also allows several control groups that are virtually grouped by mm_struct, to exist independent of the memory controller i.e., without adding mem_cgroup's for each controller, to mm_struct. A new config option CONFIG_MM_OWNER is added and the memory resource controller selects this config option. This patch also adds cgroup callbacks to notify subsystems when mm->owner changes. The mm_cgroup_changed callback is called with the task_lock() of the new task held and is called just prior to changing the mm->owner. I am indebted to Paul Menage for the several reviews of this patchset and helping me make it lighter and simpler. This patch was tested on a powerpc box, it was compiled with both the MM_OWNER config turned on and off. After the thread group leader exits, it's moved to init_css_state by cgroup_exit(), thus all future charges from runnings threads would be redirected to the init_css_set's subsystem. Signed-off-by: Balbir Singh Cc: Pavel Emelianov Cc: Hugh Dickins Cc: Sudhir Kumar Cc: YAMAMOTO Takashi Cc: Hirokazu Takahashi Cc: David Rientjes , Cc: Balbir Singh Acked-by: KAMEZAWA Hiroyuki Acked-by: Pekka Enberg Reviewed-by: Paul Menage Cc: Oleg Nesterov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mempolicy: rename mpol_copy to mpol_dup

2008-04-28T15:58:23Z

This patch renames mpol_copy() to mpol_dup() because, well, that's what it does. Like, e.g., strdup() for strings, mpol_dup() takes a pointer to an existing mempolicy, allocates a new one and copies the contents. In a later patch, I want to use the name mpol_copy() to copy the contents from one mempolicy to another like, e.g., strcpy() does for strings. Signed-off-by: Lee Schermerhorn Cc: Christoph Lameter Cc: David Rientjes Cc: Mel Gorman Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mempolicy: rename mpol_free to mpol_put

2008-04-28T15:58:23Z

This is a change that was requested some time ago by Mel Gorman. Makes sense to me, so here it is. Note: I retain the name "mpol_free_shared_policy()" because it actually does free the shared_policy, which is NOT a reference counted object. However, ... The mempolicy object[s] referenced by the shared_policy are reference counted, so mpol_put() is used to release the reference held by the shared_policy. The mempolicy might not be freed at this time, because some task attached to the shared object associated with the shared policy may be in the process of allocating a page based on the mempolicy. In that case, the task performing the allocation will hold a reference on the mempolicy, obtained via mpol_shared_policy_lookup(). The mempolicy will be freed when all tasks holding such a reference have called mpol_put() for the mempolicy. Signed-off-by: Lee Schermerhorn Cc: Christoph Lameter Cc: David Rientjes Cc: Mel Gorman Cc: Andi Kleen Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

s390: KVM preparation: provide hook to enable pgstes in user pagetable

2008-04-27T09:00:40Z

The SIE instruction on s390 uses the 2nd half of the page table page to virtualize the storage keys of a guest. This patch offers the s390_enable_sie function, which reorganizes the page tables of a single-threaded process to reserve space in the page table: s390_enable_sie makes sure that the process is single threaded and then uses dup_mm to create a new mm with reorganized page tables. The old mm is freed and the process has now a page status extended field after every page table. Code that wants to exploit pgstes should SELECT CONFIG_PGSTE. This patch has a small common code hit, namely making dup_mm non-static. Edit (Carsten): I've modified Martin's patch, following Jeremy Fitzhardinge's review feedback. Now we do have the prototype for dup_mm in include/linux/sched.h. Following Martin's suggestion, s390_enable_sie() does now call task_lock() to prevent race against ptrace modification of mm_users. Signed-off-by: Martin Schwidefsky Signed-off-by: Carsten Otte Acked-by: Andrew Morton Signed-off-by: Avi Kivity