linux/kernel/sys.c, branch v3.9

PM / reboot: call syscore_shutdown() after disable_nonboot_cpus()

2013-04-08T20:10:40Z

As commit 40dc166c (PM / Core: Introduce struct syscore_ops for core subsystems PM) say, syscore_ops operations should be carried with one CPU on-line and interrupts disabled. However, after commit f96972f2d (kernel/sys.c: call disable_nonboot_cpus() in kernel_restart()), syscore_shutdown() is called before disable_nonboot_cpus(), so break the rules. We have a MIPS machine with a 8259A PIC, and there is an external timer (HPET) linked at 8259A. Since 8259A has been shutdown too early (by syscore_shutdown()), disable_nonboot_cpus() runs without timer interrupt, so it hangs and reboot fails. This patch call syscore_shutdown() a little later (after disable_nonboot_cpus()) to avoid reboot failure, this is the same way as poweroff does. For consistency, add disable_nonboot_cpus() to kernel_halt(). Signed-off-by: Huacai Chen Cc: Signed-off-by: Rafael J. Wysocki

poweroff: change orderly_poweroff() to use schedule_work()

2013-03-22T23:41:20Z

David said: Commit 6c0c0d4d1080 ("poweroff: fix bug in orderly_poweroff()") apparently fixes one bug in orderly_poweroff(), but introduces another. The comments on orderly_poweroff() claim it can be called from any context - and indeed we call it from interrupt context in arch/powerpc/platforms/pseries/ras.c for example. But since that commit this is no longer safe, since call_usermodehelper_fns() is not safe in interrupt context without the UMH_NO_WAIT option. orderly_poweroff() can be used from any context but UMH_WAIT_EXEC is sleepable. Move the "force" logic into __orderly_poweroff() and change orderly_poweroff() to use the global poweroff_work which simply calls __orderly_poweroff(). While at it, remove the unneeded "int argc" and change argv_split() to use GFP_KERNEL. We use the global "bool poweroff_force" to pass the argument, this can obviously affect the previous request if it is pending/running. So we only allow the "false => true" transition assuming that the pending "true" should succeed anyway. If schedule_work() fails after that we know that work->func() was not called yet, it must see the new value. This means that orderly_poweroff() becomes async even if we do not run the command and always succeeds, schedule_work() can only fail if the work is already pending. We can export __orderly_poweroff() and change the non-atomic callers which want the old semantics. Signed-off-by: Oleg Nesterov Reported-by: Benjamin Herrenschmidt Reported-by: David Gibson Cc: Lucas De Marchi Cc: Feng Hong Cc: Kees Cook Cc: Serge Hallyn Cc: "Eric W. Biederman" Cc: "Rafael J. Wysocki" Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

usermodehelper: cleanup/fix __orderly_poweroff() && argv_free()

2013-02-28T03:10:09Z

__orderly_poweroff() does argv_free() if call_usermodehelper_fns() returns -ENOMEM. As Lucas pointed out, this can be wrong if -ENOMEM was not triggered by the failing call_usermodehelper_setup(), in this case both __orderly_poweroff() and argv_cleanup() can do kfree(). Kill argv_cleanup() and change __orderly_poweroff() to call argv_free() unconditionally like do_coredump() does. This info->cleanup() is not needed (and wrong) since 6c0c0d4d "fix bug in orderly_poweroff() which did the UMH_NO_WAIT => UMH_WAIT_EXEC change, we can rely on the fact that CLONE_VFORK can't return until do_execve() succeeds/fails. Signed-off-by: Oleg Nesterov Reported-by: Lucas De Marchi Cc: David Howells Cc: James Morris Cc: hongfeng Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2013-02-27T04:16:07Z

Pull vfs pile (part one) from Al Viro: "Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent locking violations, etc. The most visible changes here are death of FS_REVAL_DOT (replaced with "has ->d_weak_revalidate()") and a new helper getting from struct file to inode. Some bits of preparation to xattr method interface changes. Misc patches by various people sent this cycle *and* ocfs2 fixes from several cycles ago that should've been upstream right then. PS: the next vfs pile will be xattr stuff." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits) saner proc_get_inode() calling conventions proc: avoid extra pde_put() in proc_fill_super() fs: change return values from -EACCES to -EPERM fs/exec.c: make bprm_mm_init() static ocfs2/dlm: use GFP_ATOMIC inside a spin_lock ocfs2: fix possible use-after-free with AIO ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero target: writev() on single-element vector is pointless export kernel_write(), convert open-coded instances fs: encode_fh: return FILEID_INVALID if invalid fid_type kill f_vfsmnt vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op nfsd: handle vfs_getattr errors in acl protocol switch vfs_getattr() to struct path default SET_PERSONALITY() in linux/elf.h ceph: prepopulate inodes only when request is aborted d_hash_and_lookup(): export, switch open-coded instances 9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate() 9p: split dropping the acls from v9fs_set_create_acl() ...

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace

2013-02-26T00:00:49Z

Pull user namespace and namespace infrastructure changes from Eric W Biederman: "This set of changes starts with a few small enhnacements to the user namespace. reboot support, allowing more arbitrary mappings, and support for mounting devpts, ramfs, tmpfs, and mqueuefs as just the user namespace root. I do my best to document that if you care about limiting your unprivileged users that when you have the user namespace support enabled you will need to enable memory control groups. There is a minor bug fix to prevent overflowing the stack if someone creates way too many user namespaces. The bulk of the changes are a continuation of the kuid/kgid push down work through the filesystems. These changes make using uids and gids typesafe which ensures that these filesystems are safe to use when multiple user namespaces are in use. The filesystems converted for 3.9 are ceph, 9p, afs, ocfs2, gfs2, ncpfs, nfs, nfsd, and cifs. The changes for these filesystems were a little more involved so I split the changes into smaller hopefully obviously correct changes. XFS is the only filesystem that remains. I was hoping I could get that in this release so that user namespace support would be enabled with an allyesconfig or an allmodconfig but it looks like the xfs changes need another couple of days before it they are ready." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (93 commits) cifs: Enable building with user namespaces enabled. cifs: Convert struct cifs_ses to use a kuid_t and a kgid_t cifs: Convert struct cifs_sb_info to use kuids and kgids cifs: Modify struct smb_vol to use kuids and kgids cifs: Convert struct cifsFileInfo to use a kuid cifs: Convert struct cifs_fattr to use kuid and kgids cifs: Convert struct tcon_link to use a kuid. cifs: Modify struct cifs_unix_set_info_args to hold a kuid_t and a kgid_t cifs: Convert from a kuid before printing current_fsuid cifs: Use kuids and kgids SID to uid/gid mapping cifs: Pass GLOBAL_ROOT_UID and GLOBAL_ROOT_GID to keyring_alloc cifs: Use BUILD_BUG_ON to validate uids and gids are the same size cifs: Override unmappable incoming uids and gids nfsd: Enable building with user namespaces enabled. nfsd: Properly compare and initialize kuids and kgids nfsd: Store ex_anon_uid and ex_anon_gid as kuids and kgids nfsd: Modify nfsd4_cb_sec to use kuids and kgids nfsd: Handle kuids and kgids in the nfs4acl to posix_acl conversion nfsd: Convert nfsxdr to use kuids and kgids nfsd: Convert nfs3xdr to use kuids and kgids ...

new helper: file_inode(file)

2013-02-23T04:31:31Z

Signed-off-by: Al Viro

sys_prctl(): coding-style cleanup

2013-02-22T01:22:20Z

Remove a tabstop from the switch statement, in the usual fashion. A few instances of weirdwrapping were removed as a result. Cc: Chen Gang Cc: Cyrill Gorcunov Acked-by: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

sys_prctl(): arg2 is unsigned long which is never < 0

2013-02-22T01:22:20Z

arg2 will never < 0, for its type is 'unsigned long' Also, use the provided macros. Signed-off-by: Chen Gang Reported-by: Cyrill Gorcunov Acked-by: Kees Cook Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

userns: Allow unprivileged reboot

2012-12-27T04:29:30Z

In a container with its own pid namespace and user namespace, rebooting the system won't reboot the host, but terminate all the processes in it and thus have the container shutdown, so it's safe. Signed-off-by: Li Zefan Signed-off-by: Eric W. Biederman

cputime: Rename thread_group_times to thread_group_cputime_adjusted

2012-11-28T16:07:57Z

We have thread_group_cputime() and thread_group_times(). The naming doesn't provide enough information about the difference between these two APIs. To lower the confusion, rename thread_group_times() to thread_group_cputime_adjusted(). This name better suggests that it's a version of thread_group_cputime() that does some stabilization on the raw cputime values. ie here: scale on top of CFS runtime stats and bound lower value for monotonicity. Signed-off-by: Frederic Weisbecker Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Steven Rostedt Cc: Paul Gortmaker