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* Merge branch 'next' of ↵Linus Torvalds2012-10-021-42/+12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "Highlights: - Integrity: add local fs integrity verification to detect offline attacks - Integrity: add digital signature verification - Simple stacking of Yama with other LSMs (per LSS discussions) - IBM vTPM support on ppc64 - Add new driver for Infineon I2C TIS TPM - Smack: add rule revocation for subject labels" Fixed conflicts with the user namespace support in kernel/auditsc.c and security/integrity/ima/ima_policy.c. * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (39 commits) Documentation: Update git repository URL for Smack userland tools ima: change flags container data type Smack: setprocattr memory leak fix Smack: implement revoking all rules for a subject label Smack: remove task_wait() hook. ima: audit log hashes ima: generic IMA action flag handling ima: rename ima_must_appraise_or_measure audit: export audit_log_task_info tpm: fix tpm_acpi sparse warning on different address spaces samples/seccomp: fix 31 bit build on s390 ima: digital signature verification support ima: add support for different security.ima data types ima: add ima_inode_setxattr/removexattr function and calls ima: add inode_post_setattr call ima: replace iint spinblock with rwlock/read_lock ima: allocating iint improvements ima: add appraise action keywords and default rules ima: integrity appraisal extension vfs: move ima_file_free before releasing the file ...
| * tpm: Move tpm_get_random api into the TPM device driverKent Yoder2012-08-221-42/+12
| | | | | | | | | | | | | | | | | | | | | | | | Move the tpm_get_random api from the trusted keys code into the TPM device driver itself so that other callers can make use of it. Also, change the api slightly so that the number of bytes read is returned in the call, since the TPM command can potentially return fewer bytes than requested. Acked-by: David Safford <safford@linux.vnet.ibm.com> Reviewed-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Kent Yoder <key@linux.vnet.ibm.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-10-028-83/+79
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace changes from Eric Biederman: "This is a mostly modest set of changes to enable basic user namespace support. This allows the code to code to compile with user namespaces enabled and removes the assumption there is only the initial user namespace. Everything is converted except for the most complex of the filesystems: autofs4, 9p, afs, ceph, cifs, coda, fuse, gfs2, ncpfs, nfs, ocfs2 and xfs as those patches need a bit more review. The strategy is to push kuid_t and kgid_t values are far down into subsystems and filesystems as reasonable. Leaving the make_kuid and from_kuid operations to happen at the edge of userspace, as the values come off the disk, and as the values come in from the network. Letting compile type incompatible compile errors (present when user namespaces are enabled) guide me to find the issues. The most tricky areas have been the places where we had an implicit union of uid and gid values and were storing them in an unsigned int. Those places were converted into explicit unions. I made certain to handle those places with simple trivial patches. Out of that work I discovered we have generic interfaces for storing quota by projid. I had never heard of the project identifiers before. Adding full user namespace support for project identifiers accounts for most of the code size growth in my git tree. Ultimately there will be work to relax privlige checks from "capable(FOO)" to "ns_capable(user_ns, FOO)" where it is safe allowing root in a user names to do those things that today we only forbid to non-root users because it will confuse suid root applications. While I was pushing kuid_t and kgid_t changes deep into the audit code I made a few other cleanups. I capitalized on the fact we process netlink messages in the context of the message sender. I removed usage of NETLINK_CRED, and started directly using current->tty. Some of these patches have also made it into maintainer trees, with no problems from identical code from different trees showing up in linux-next. After reading through all of this code I feel like I might be able to win a game of kernel trivial pursuit." Fix up some fairly trivial conflicts in netfilter uid/git logging code. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (107 commits) userns: Convert the ufs filesystem to use kuid/kgid where appropriate userns: Convert the udf filesystem to use kuid/kgid where appropriate userns: Convert ubifs to use kuid/kgid userns: Convert squashfs to use kuid/kgid where appropriate userns: Convert reiserfs to use kuid and kgid where appropriate userns: Convert jfs to use kuid/kgid where appropriate userns: Convert jffs2 to use kuid and kgid where appropriate userns: Convert hpfs to use kuid and kgid where appropriate userns: Convert btrfs to use kuid/kgid where appropriate userns: Convert bfs to use kuid/kgid where appropriate userns: Convert affs to use kuid/kgid wherwe appropriate userns: On alpha modify linux_to_osf_stat to use convert from kuids and kgids userns: On ia64 deal with current_uid and current_gid being kuid and kgid userns: On ppc convert current_uid from a kuid before printing. userns: Convert s390 getting uid and gid system calls to use kuid and kgid userns: Convert s390 hypfs to use kuid and kgid where appropriate userns: Convert binder ipc to use kuids userns: Teach security_path_chown to take kuids and kgids userns: Add user namespace support to IMA userns: Convert EVM to deal with kuids and kgids in it's hmac computation ...
| * | userns: Convert security/keys to the new userns infrastructureEric W. Biederman2012-09-138-83/+79
| |/ | | | | | | | | | | | | | | | | | | | | | | | | - Replace key_user ->user_ns equality checks with kuid_has_mapping checks. - Use from_kuid to generate key descriptions - Use kuid_t and kgid_t and the associated helpers instead of uid_t and gid_t - Avoid potential problems with file descriptor passing by displaying keys in the user namespace of the opener of key status proc files. Cc: linux-security-module@vger.kernel.org Cc: keyrings@linux-nfs.org Cc: David Howells <dhowells@redhat.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* | Merge branch 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds2012-10-022-5/+5
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull workqueue changes from Tejun Heo: "This is workqueue updates for v3.7-rc1. A lot of activities this round including considerable API and behavior cleanups. * delayed_work combines a timer and a work item. The handling of the timer part has always been a bit clunky leading to confusing cancelation API with weird corner-case behaviors. delayed_work is updated to use new IRQ safe timer and cancelation now works as expected. * Another deficiency of delayed_work was lack of the counterpart of mod_timer() which led to cancel+queue combinations or open-coded timer+work usages. mod_delayed_work[_on]() are added. These two delayed_work changes make delayed_work provide interface and behave like timer which is executed with process context. * A work item could be executed concurrently on multiple CPUs, which is rather unintuitive and made flush_work() behavior confusing and half-broken under certain circumstances. This problem doesn't exist for non-reentrant workqueues. While non-reentrancy check isn't free, the overhead is incurred only when a work item bounces across different CPUs and even in simulated pathological scenario the overhead isn't too high. All workqueues are made non-reentrant. This removes the distinction between flush_[delayed_]work() and flush_[delayed_]_work_sync(). The former is now as strong as the latter and the specified work item is guaranteed to have finished execution of any previous queueing on return. * In addition to the various bug fixes, Lai redid and simplified CPU hotplug handling significantly. * Joonsoo introduced system_highpri_wq and used it during CPU hotplug. There are two merge commits - one to pull in IRQ safe timer from tip/timers/core and the other to pull in CPU hotplug fixes from wq/for-3.6-fixes as Lai's hotplug restructuring depended on them." Fixed a number of trivial conflicts, but the more interesting conflicts were silent ones where the deprecated interfaces had been used by new code in the merge window, and thus didn't cause any real data conflicts. Tejun pointed out a few of them, I fixed a couple more. * 'for-3.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: (46 commits) workqueue: remove spurious WARN_ON_ONCE(in_irq()) from try_to_grab_pending() workqueue: use cwq_set_max_active() helper for workqueue_set_max_active() workqueue: introduce cwq_set_max_active() helper for thaw_workqueues() workqueue: remove @delayed from cwq_dec_nr_in_flight() workqueue: fix possible stall on try_to_grab_pending() of a delayed work item workqueue: use hotcpu_notifier() for workqueue_cpu_down_callback() workqueue: use __cpuinit instead of __devinit for cpu callbacks workqueue: rename manager_mutex to assoc_mutex workqueue: WORKER_REBIND is no longer necessary for idle rebinding workqueue: WORKER_REBIND is no longer necessary for busy rebinding workqueue: reimplement idle worker rebinding workqueue: deprecate __cancel_delayed_work() workqueue: reimplement cancel_delayed_work() using try_to_grab_pending() workqueue: use mod_delayed_work() instead of __cancel + queue workqueue: use irqsafe timer for delayed_work workqueue: clean up delayed_work initializers and add missing one workqueue: make deferrable delayed_work initializer names consistent workqueue: cosmetic whitespace updates for macro definitions workqueue: deprecate system_nrt[_freezable]_wq workqueue: deprecate flush[_delayed]_work_sync() ...
| * | workqueue: deprecate system_nrt[_freezable]_wqTejun Heo2012-08-202-5/+5
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | system_nrt[_freezable]_wq are now spurious. Mark them deprecated and convert all users to system[_freezable]_wq. If you're cc'd and wondering what's going on: Now all workqueues are non-reentrant, so there's no reason to use system_nrt[_freezable]_wq. Please use system[_freezable]_wq instead. This patch doesn't make any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-By: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: David Airlie <airlied@linux.ie> Cc: Jiri Kosina <jkosina@suse.cz> Cc: "David S. Miller" <davem@davemloft.net> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: David Howells <dhowells@redhat.com>
* | task_work: Revert "hold task_lock around checks in keyctl"Oleg Nesterov2012-09-131-2/+0
|/ | | | | | | | | | | | | | | | | | | | This reverts commit d35abdb28824cf74f0a106a0f9c6f3ff700a35bf. task_lock() was added to ensure exit_mm() and thus exit_task_work() is not possible before task_work_add(). This is wrong, task_lock() must not be nested with write_lock(tasklist). And this is no longer needed, task_work_add() now fails if it is called after exit_task_work(). Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/20120826191214.GA4231@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* Merge branch 'next' of ↵Linus Torvalds2012-07-234-4/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "Nothing groundbreaking for this kernel, just cleanups and fixes, and a couple of Smack enhancements." * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (21 commits) Smack: Maintainer Record Smack: don't show empty rules when /smack/load or /smack/load2 is read Smack: user access check bounds Smack: onlycap limits on CAP_MAC_ADMIN Smack: fix smack_new_inode bogosities ima: audit is compiled only when enabled ima: ima_initialized is set only if successful ima: add policy for pseudo fs ima: remove unused cleanup functions ima: free securityfs violations file ima: use full pathnames in measurement list security: Fix nommu build. samples: seccomp: add .gitignore for untracked executables tpm: check the chip reference before using it TPM: fix memleak when register hardware fails TPM: chip disabled state erronously being reported as error MAINTAINERS: TPM maintainers' contacts update Merge branches 'next-queue' and 'next' into next Remove unused code from MPI library Revert "crypto: GnuPG based MPI lib - additional sources (part 4)" ...
| * Merge commit 'v3.5-rc2' into nextJames Morris2012-06-107-68/+55
| |\
| * | KEYS: Fix some sparse warningsDavid Howells2012-05-254-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix some sparse warnings in the keyrings code: (1) compat_keyctl_instantiate_key_iov() should be static. (2) There were a couple of places where a pointer was being compared against integer 0 rather than NULL. (3) keyctl_instantiate_key_common() should not take a __user-labelled iovec pointer as the caller must have copied the iovec to kernel space. (4) __key_link_begin() takes and __key_link_end() releases keyring_serialise_link_sem under some circumstances and so this should be declared. Note that adding __acquires() and __releases() for this doesn't help cure the warnings messages - something only commenting out both helps. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
* | | hold task_lock around checks in keyctlAl Viro2012-07-221-0/+2
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | merge task_work and rcu_head, get rid of separate allocation for keyring caseAl Viro2012-07-223-28/+12
| | | | | | | | | | | | | | | | | | | | | | | | task_work and rcu_head are identical now; merge them (calling the result struct callback_head, rcu_head #define'd to it), kill separate allocation in security/keys since we can just use cred->rcu now. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | trimming task_work: kill ->dataAl Viro2012-07-223-8/+15
| |/ |/| | | | | | | | | | | | | get rid of the only user of ->data; this is _not_ the final variant - in the end we'll have task_work and rcu_head identical and just use cred->rcu, at which point the separate allocation will be gone completely. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-05-313-51/+44
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull second pile of signal handling patches from Al Viro: "This one is just task_work_add() series + remaining prereqs for it. There probably will be another pull request from that tree this cycle - at least for helpers, to get them out of the way for per-arch fixes remaining in the tree." Fix trivial conflict in kernel/irq/manage.c: the merge of Andrew's pile had brought in commit 97fd75b7b8e0 ("kernel/irq/manage.c: use the pr_foo() infrastructure to prefix printks") which changed one of the pr_err() calls that this merge moves around. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: keys: kill task_struct->replacement_session_keyring keys: kill the dummy key_replace_session_keyring() keys: change keyctl_session_to_parent() to use task_work_add() genirq: reimplement exit_irq_thread() hook via task_work_add() task_work_add: generic process-context callbacks avr32: missed _TIF_NOTIFY_RESUME on one of do_notify_resume callers parisc: need to check NOTIFY_RESUME when exiting from syscall move key_repace_session_keyring() into tracehook_notify_resume() TIF_NOTIFY_RESUME is defined on all targets now
| * | keys: change keyctl_session_to_parent() to use task_work_add()Oleg Nesterov2012-05-233-41/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change keyctl_session_to_parent() to use task_work_add() and move key_replace_session_keyring() logic into task_work->func(). Note that we do task_work_cancel() before task_work_add() to ensure that only one work can be pending at any time. This is important, we must not allow user-space to abuse the parent's ->task_works list. The callback, replace_session_keyring(), checks PF_EXITING. I guess this is not really needed but looks better. As a side effect, this fixes the (unlikely) race. The callers of key_replace_session_keyring() and keyctl_session_to_parent() lack the necessary barriers, the parent can miss the request. Now we can remove task_struct->replacement_session_keyring and related code. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Alexander Gordeev <agordeev@redhat.com> Cc: Chris Zankel <chris@zankel.net> Cc: David Smith <dsmith@redhat.com> Cc: "Frank Ch. Eigler" <fche@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | TIF_NOTIFY_RESUME is defined on all targets nowAl Viro2012-05-231-10/+0
| | | | | | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()Christopher Yeoh2012-05-312-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A cleanup of rw_copy_check_uvector and compat_rw_copy_check_uvector after changes made to support CMA in an earlier patch. Rather than having an additional check_access parameter to these functions, the first paramater type is overloaded to allow the caller to specify CHECK_IOVEC_ONLY which means check that the contents of the iovec are valid, but do not check the memory that they point to. This is used by process_vm_readv/writev where we need to validate that a iovec passed to the syscall is valid but do not want to check the memory that it points to at this point because it refers to an address space in another process. Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | kmod: convert two call sites to call_usermodehelper_fns()Boaz Harrosh2012-05-311-10/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Both kernel/sys.c && security/keys/request_key.c where inlining the exact same code as call_usermodehelper_fns(); So simply convert these sites to directly use call_usermodehelper_fns(). Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | security/keys/keyctl.c: suppress memory allocation failure warningAndrew Morton2012-05-311-1/+1
|/ / | | | | | | | | | | | | | | | | | | | | | | This allocation may be large. The code is probing to see if it will succeed and if not, it falls back to vmalloc(). We should suppress any page-allocation failure messages when the fallback happens. Reported-by: Dave Jones <davej@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-05-233-4/+5
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace enhancements from Eric Biederman: "This is a course correction for the user namespace, so that we can reach an inexpensive, maintainable, and reasonably complete implementation. Highlights: - Config guards make it impossible to enable the user namespace and code that has not been converted to be user namespace safe. - Use of the new kuid_t type ensures the if you somehow get past the config guards the kernel will encounter type errors if you enable user namespaces and attempt to compile in code whose permission checks have not been updated to be user namespace safe. - All uids from child user namespaces are mapped into the initial user namespace before they are processed. Removing the need to add an additional check to see if the user namespace of the compared uids remains the same. - With the user namespaces compiled out the performance is as good or better than it is today. - For most operations absolutely nothing changes performance or operationally with the user namespace enabled. - The worst case performance I could come up with was timing 1 billion cache cold stat operations with the user namespace code enabled. This went from 156s to 164s on my laptop (or 156ns to 164ns per stat operation). - (uid_t)-1 and (gid_t)-1 are reserved as an internal error value. Most uid/gid setting system calls treat these value specially anyway so attempting to use -1 as a uid would likely cause entertaining failures in userspace. - If setuid is called with a uid that can not be mapped setuid fails. I have looked at sendmail, login, ssh and every other program I could think of that would call setuid and they all check for and handle the case where setuid fails. - If stat or a similar system call is called from a context in which we can not map a uid we lie and return overflowuid. The LFS experience suggests not lying and returning an error code might be better, but the historical precedent with uids is different and I can not think of anything that would break by lying about a uid we can't map. - Capabilities are localized to the current user namespace making it safe to give the initial user in a user namespace all capabilities. My git tree covers all of the modifications needed to convert the core kernel and enough changes to make a system bootable to runlevel 1." Fix up trivial conflicts due to nearby independent changes in fs/stat.c * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (46 commits) userns: Silence silly gcc warning. cred: use correct cred accessor with regards to rcu read lock userns: Convert the move_pages, and migrate_pages permission checks to use uid_eq userns: Convert cgroup permission checks to use uid_eq userns: Convert tmpfs to use kuid and kgid where appropriate userns: Convert sysfs to use kgid/kuid where appropriate userns: Convert sysctl permission checks to use kuid and kgids. userns: Convert proc to use kuid/kgid where appropriate userns: Convert ext4 to user kuid/kgid where appropriate userns: Convert ext3 to use kuid/kgid where appropriate userns: Convert ext2 to use kuid/kgid where appropriate. userns: Convert devpts to use kuid/kgid where appropriate userns: Convert binary formats to use kuid/kgid where appropriate userns: Add negative depends on entries to avoid building code that is userns unsafe userns: signal remove unnecessary map_cred_ns userns: Teach inode_capable to understand inodes whose uids map to other namespaces. userns: Fail exec for suid and sgid binaries with ids outside our user namespace. userns: Convert stat to return values mapped from kuids and kgids userns: Convert user specfied uids and gids in chown into kuids and kgid userns: Use uid_eq gid_eq helpers when comparing kuids and kgids in the vfs ...
| * userns: Convert group_info values from gid_t to kgid_t.Eric W. Biederman2012-05-031-1/+2
| | | | | | | | | | | | | | | | | | | | As a first step to converting struct cred to be all kuid_t and kgid_t values convert the group values stored in group_info to always be kgid_t values. Unless user namespaces are used this change should have no effect. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * cred: Refcount the user_ns pointed to by the cred.Eric W. Biederman2012-04-071-1/+1
| | | | | | | | | | | | | | | | | | struct user_struct will shortly loose it's user_ns reference so make the cred user_ns reference a proper reference complete with reference counting. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| * userns: Use cred->user_ns instead of cred->user->user_nsEric W. Biederman2012-04-073-3/+3
| | | | | | | | | | | | | | | | | | Optimize performance and prepare for the removal of the user_ns reference from user_struct. Remove the slow long walk through cred->user->user_ns and instead go straight to cred->user_ns. Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* | KEYS: Don't check for NULL key pointer in key_validate()David Howells2012-05-161-24/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't bother checking for NULL key pointer in key_validate() as all of the places that call it will crash anyway if the relevant key pointer is NULL by the time they call key_validate(). Therefore, the checking must be done prior to calling here. Whilst we're at it, simplify the key_validate() function a bit and mark its argument const. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
* | KEYS: Add invalidation supportDavid Howells2012-05-118-28/+110
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for invalidating a key - which renders it immediately invisible to further searches and causes the garbage collector to immediately wake up, remove it from keyrings and then destroy it when it's no longer referenced. It's better not to do this with keyctl_revoke() as that marks the key to start returning -EKEYREVOKED to searches when what is actually desired is to have the key refetched. To invalidate a key the caller must be granted SEARCH permission by the key. This may be too strict. It may be better to also permit invalidation if the caller has any of READ, WRITE or SETATTR permission. The primary use for this is to evict keys that are cached in special keyrings, such as the DNS resolver or an ID mapper. Signed-off-by: David Howells <dhowells@redhat.com>
* | KEYS: Do LRU discard in full keyringsDavid Howells2012-05-112-7/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do an LRU discard in keyrings that are full rather than returning ENFILE. To perform this, a time_t is added to the key struct and updated by the creation of a link to a key and by a key being found as the result of a search. At the completion of a successful search, the keyrings in the path between the root of the search and the first found link to it also have their last-used times updated. Note that discarding a link to a key from a keyring does not necessarily destroy the key as there may be references held by other places. An alternate discard method that might suffice is to perform FIFO discard from the keyring, using the spare 2-byte hole in the keylist header as the index of the next link to be discarded. This is useful when using a keyring as a cache for DNS results or foreign filesystem IDs. This can be tested by the following. As root do: echo 1000 >/proc/sys/kernel/keys/root_maxkeys kr=`keyctl newring foo @s` for ((i=0; i<2000; i++)); do keyctl add user a$i a $kr; done Without this patch ENFILE should be reported when the keyring fills up. With this patch, the keyring discards keys in an LRU fashion. Note that the stored LRU time has a granularity of 1s. After doing this, /proc/key-users can be observed and should show that most of the 2000 keys have been discarded: [root@andromeda ~]# cat /proc/key-users 0: 517 516/516 513/1000 5249/20000 The "513/1000" here is the number of quota-accounted keys present for this user out of the maximum permitted. In /proc/keys, the keyring shows the number of keys it has and the number of slots it has allocated: [root@andromeda ~]# grep foo /proc/keys 200c64c4 I--Q-- 1 perm 3b3f0000 0 0 keyring foo: 509/509 The maximum is (PAGE_SIZE - header) / key pointer size. That's typically 509 on a 64-bit system and 1020 on a 32-bit system. Signed-off-by: David Howells <dhowells@redhat.com>
* | KEYS: Permit in-place link replacement in keyring listDavid Howells2012-05-112-40/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Make use of the previous patch that makes the garbage collector perform RCU synchronisation before destroying defunct keys. Key pointers can now be replaced in-place without creating a new keyring payload and replacing the whole thing as the discarded keys will not be destroyed until all currently held RCU read locks are released. If the keyring payload space needs to be expanded or contracted, then a replacement will still need allocating, and the original will still have to be freed by RCU. Signed-off-by: David Howells <dhowells@redhat.com>
* | KEYS: Perform RCU synchronisation on keys prior to key destructionDavid Howells2012-05-111-29/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the keys garbage collector invoke synchronize_rcu() prior to destroying keys with a zero usage count. This means that a key can be examined under the RCU read lock in the safe knowledge that it won't get deallocated until after the lock is released - even if its usage count becomes zero whilst we're looking at it. This is useful in keyring search vs key link. Consider a keyring containing a link to a key. That link can be replaced in-place in the keyring without requiring an RCU copy-and-replace on the keyring contents without breaking a search underway on that keyring when the displaced key is released, provided the key is actually destroyed only after the RCU read lock held by the search algorithm is released. This permits __key_link() to replace a key without having to reallocate the key payload. A key gets replaced if a new key being linked into a keyring has the same type and description. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@redhat.com>
* | KEYS: Announce key type (un)registrationDavid Howells2012-05-111-0/+3
| | | | | | | | | | | | | | | | Announce the (un)registration of a key type in the core key code rather than in the callers. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mimi Zohar <zohar@us.ibm.com>
* | KEYS: Reorganise keys MakefileDavid Howells2012-05-111-3/+9
| | | | | | | | | | | | | | | | Reorganise the keys directory Makefile to put all the core bits together and the type-specific bits after. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mimi Zohar <zohar@us.ibm.com>
* | KEYS: Move the key config into security/keys/KconfigDavid Howells2012-05-111-0/+71
|/ | | | | | | | Move the key config into security/keys/Kconfig as there are going to be a lot of key-related options. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mimi Zohar <zohar@us.ibm.com>
* usermodehelper: kill umh_wait, renumber UMH_* constantsOleg Nesterov2012-03-231-1/+1
| | | | | | | | | | | | | | No functional changes. It is not sane to use UMH_KILLABLE with enum umh_wait, but obviously we do not want another argument in call_usermodehelper_* helpers. Kill this enum, use the plain int. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Tejun Heo <tj@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'nfs-for-3.4-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds2012-03-232-16/+22
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull NFS client updates for Linux 3.4 from Trond Myklebust: "New features include: - Add NFS client support for containers. This should enable most of the necessary functionality, including lockd support, and support for rpc.statd, NFSv4 idmapper and RPCSEC_GSS upcalls into the correct network namespace from which the mount system call was issued. - NFSv4 idmapper scalability improvements Base the idmapper cache on the keyring interface to allow concurrent access to idmapper entries. Start the process of migrating users from the single-threaded daemon-based approach to the multi-threaded request-key based approach. - NFSv4.1 implementation id. Allows the NFSv4.1 client and server to mutually identify each other for logging and debugging purposes. - Support the 'vers=4.1' mount option for mounting NFSv4.1 instead of having to use the more counterintuitive 'vers=4,minorversion=1'. - SUNRPC tracepoints. Start the process of adding tracepoints in order to improve debugging of the RPC layer. - pNFS object layout support for autologin. Important bugfixes include: - Fix a bug in rpc_wake_up/rpc_wake_up_status that caused them to fail to wake up all tasks when applied to priority waitqueues. - Ensure that we handle read delegations correctly, when we try to truncate a file. - A number of fixes for NFSv4 state manager loops (mostly to do with delegation recovery)." * tag 'nfs-for-3.4-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (224 commits) NFS: fix sb->s_id in nfs debug prints xprtrdma: Remove assumption that each segment is <= PAGE_SIZE xprtrdma: The transport should not bug-check when a dup reply is received pnfs-obj: autologin: Add support for protocol autologin NFS: Remove nfs4_setup_sequence from generic rename code NFS: Remove nfs4_setup_sequence from generic unlink code NFS: Remove nfs4_setup_sequence from generic read code NFS: Remove nfs4_setup_sequence from generic write code NFS: Fix more NFS debug related build warnings SUNRPC/LOCKD: Fix build warnings when CONFIG_SUNRPC_DEBUG is undefined nfs: non void functions must return a value SUNRPC: Kill compiler warning when RPC_DEBUG is unset SUNRPC/NFS: Add Kbuild dependencies for NFS_DEBUG/RPC_DEBUG NFS: Use cond_resched_lock() to reduce latencies in the commit scans NFSv4: It is not safe to dereference lsp->ls_state in release_lockowner NFS: ncommit count is being double decremented SUNRPC: We must not use list_for_each_entry_safe() in rpc_wake_up() Try using machine credentials for RENEW calls NFSv4.1: Fix a few issues in filelayout_commit_pagelist NFSv4.1: Clean ups and bugfixes for the pNFS read/writeback/commit code ...
| * Created a function for setting timeouts on keysBryan Schumaker2012-03-012-16/+22
| | | | | | | | | | | | | | | | | | | | The keyctl_set_timeout function isn't exported to other parts of the kernel, but I want to use it for the NFS idmapper. I already have the key, but I wanted a generic way to set the timeout. Signed-off-by: Bryan Schumaker <bjschuma@netapp.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* | KEYS: testing wrong bit for KEY_FLAG_REVOKEDDan Carpenter2012-03-071-1/+2
| | | | | | | | | | | | | | | | | | | | The test for "if (cred->request_key_auth->flags & KEY_FLAG_REVOKED) {" should actually testing that the (1 << KEY_FLAG_REVOKED) bit is set. The current code actually checks for KEY_FLAG_DEAD. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
* | Merge branch 'next-queue' into nextJames Morris2012-02-091-1/+14
|\ \ | |/ |/|
| * KEYS: Allow special keyrings to be clearedDavid Howells2012-01-191-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel contains some special internal keyrings, for instance the DNS resolver keyring : 2a93faf1 I----- 1 perm 1f030000 0 0 keyring .dns_resolver: empty It would occasionally be useful to allow the contents of such keyrings to be flushed by root (cache invalidation). Allow a flag to be set on a keyring to mark that someone possessing the sysadmin capability can clear the keyring, even without normal write access to the keyring. Set this flag on the special keyrings created by the DNS resolver, the NFS identity mapper and the CIFS identity mapper. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* | Merge git://git.samba.org/sfrench/cifs-2.6Linus Torvalds2012-01-233-0/+39
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.samba.org/sfrench/cifs-2.6: CIFS: Rename *UCS* functions to *UTF16* [CIFS] ACL and FSCACHE support no longer EXPERIMENTAL [CIFS] Fix build break with multiuser patch when LANMAN disabled cifs: warn about impending deprecation of legacy MultiuserMount code cifs: fetch credentials out of keyring for non-krb5 auth multiuser mounts cifs: sanitize username handling keys: add a "logon" key type cifs: lower default wsize when unix extensions are not used cifs: better instrumentation for coalesce_t2 cifs: integer overflow in parse_dacl() cifs: Fix sparse warning when calling cifs_strtoUCS CIFS: Add descriptions to the brlock cache functions
| * | keys: add a "logon" key typeJeff Layton2012-01-173-0/+39
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For CIFS, we want to be able to store NTLM credentials (aka username and password) in the keyring. We do not, however want to allow users to fetch those keys back out of the keyring since that would be a security risk. Unfortunately, due to the nuances of key permission bits, it's not possible to do this. We need to grant search permissions so the kernel can find these keys, but that also implies permissions to read the payload. Resolve this by adding a new key_type. This key type is essentially the same as key_type_user, but does not define a .read op. This prevents the payload from ever being visible from userspace. This key type also vets the description to ensure that it's "qualified" by checking to ensure that it has a ':' in it that is preceded by other characters. Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Steve French <smfrench@gmail.com>
* | keys: fix user_defined key sparse messagesMimi Zohar2012-01-191-3/+3
| | | | | | | | | | | | | | | | Replace the rcu_assign_pointer() calls with rcu_assign_keypointer(). Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* | encrypted-keys: fix rcu and sparse messagesMimi Zohar2012-01-182-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Enabling CONFIG_PROVE_RCU and CONFIG_SPARSE_RCU_POINTER resulted in "suspicious rcu_dereference_check() usage!" and "incompatible types in comparison expression (different address spaces)" messages. Access the masterkey directly when holding the rwsem. Changelog v1: - Use either rcu_read_lock()/rcu_derefence_key()/rcu_read_unlock() or remove the unnecessary rcu_derefence() - David Howells Reported-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com> Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* | keys: fix trusted/encrypted keys sparse rcu_assign_pointer messagesMimi Zohar2012-01-183-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | Define rcu_assign_keypointer(), which uses the key payload.rcudata instead of payload.data, to resolve the CONFIG_SPARSE_RCU_POINTER message: "incompatible types in comparison expression (different address spaces)" Replace the rcu_assign_pointer() calls in encrypted/trusted keys with rcu_assign_keypointer(). Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
* | KEYS: Add missing smp_rmb() primitives to the keyring search codeDavid Howells2012-01-182-8/+18
|/ | | | | | | | | | | | | | | Add missing smp_rmb() primitives to the keyring search code. When keyring payloads are appended to without replacement (thus using up spare slots in the key pointer array), an smp_wmb() is issued between the pointer assignment and the increment of the key count (nkeys). There should be corresponding read barriers between the read of nkeys and dereferences of keys[n] when n is dependent on the value of nkeys. Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* Merge branch 'next' into for-linusJames Morris2012-01-091-0/+3
|\ | | | | | | | | | | | | | | | | Conflicts: security/integrity/evm/evm_crypto.c Resolved upstream fix vs. next conflict manually. Signed-off-by: James Morris <jmorris@namei.org>
| * KEYS: Give key types their own lockdep class for key->semDavid Howells2011-11-171-0/+3
| | | | | | | | | | | | | | | | | | Give keys their own lockdep class to differentiate them from each other in case a key of one type has to refer to a key of another type. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: James Morris <jmorris@namei.org>
* | encrypted-keys: module build fixesMimi Zohar2011-11-162-3/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Encrypted keys are encrypted/decrypted using either a trusted or user-defined key type, which is referred to as the 'master' key. The master key may be of type trusted iff the trusted key is builtin or both the trusted key and encrypted keys are built as modules. This patch resolves the build dependency problem. - Use "masterkey-$(CONFIG_TRUSTED_KEYS)-$(CONFIG_ENCRYPTED_KEYS)" construct to encapsulate the above logic. (Suggested by Dimtry Kasatkin.) - Fixing the encrypted-keys Makefile, results in a module name change from encrypted.ko to encrypted-keys.ko. - Add module dependency for request_trusted_key() definition Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
* | encrypted-keys: fix error return codeMimi Zohar2011-11-161-1/+1
|/ | | | | | Fix request_master_key() error return code. Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
* KEYS: Fix a NULL pointer deref in the user-defined key typeDavid Howells2011-11-151-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix a NULL pointer deref in the user-defined key type whereby updating a negative key into a fully instantiated key will cause an oops to occur when the code attempts to free the non-existent old payload. This results in an oops that looks something like the following: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: [<ffffffff81085fa1>] __call_rcu+0x11/0x13e PGD 3391d067 PUD 3894a067 PMD 0 Oops: 0002 [#1] SMP CPU 1 Pid: 4354, comm: keyctl Not tainted 3.1.0-fsdevel+ #1140 /DG965RY RIP: 0010:[<ffffffff81085fa1>] [<ffffffff81085fa1>] __call_rcu+0x11/0x13e RSP: 0018:ffff88003d591df8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000000000006e RDX: ffffffff8161d0c0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88003d591e18 R08: 0000000000000000 R09: ffffffff8152fa6c R10: 0000000000000000 R11: 0000000000000300 R12: ffff88003b8f9538 R13: ffffffff8161d0c0 R14: ffff88003b8f9d50 R15: ffff88003c69f908 FS: 00007f97eb18c720(0000) GS:ffff88003bd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 000000003d47a000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process keyctl (pid: 4354, threadinfo ffff88003d590000, task ffff88003c78a040) Stack: ffff88003e0ffde0 ffff88003b8f9538 0000000000000001 ffff88003b8f9d50 ffff88003d591e28 ffffffff810860f0 ffff88003d591e68 ffffffff8117bfea ffff88003d591e68 ffffffff00000000 ffff88003e0ffde1 ffff88003e0ffde0 Call Trace: [<ffffffff810860f0>] call_rcu_sched+0x10/0x12 [<ffffffff8117bfea>] user_update+0x8d/0xa2 [<ffffffff8117723a>] key_create_or_update+0x236/0x270 [<ffffffff811789b1>] sys_add_key+0x123/0x17e [<ffffffff813b84bb>] system_call_fastpath+0x16/0x1b Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jeff Layton <jlayton@redhat.com> Acked-by: Neil Horman <nhorman@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: James Morris <jmorris@namei.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* security: follow rename pack_hex_byte() to hex_byte_pack()Andy Shevchenko2011-10-312-2/+2
| | | | | | | | | | There is no functional change. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Mimi Zohar <zohar@us.ibm.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Cross Memory AttachChristopher Yeoh2011-10-312-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The basic idea behind cross memory attach is to allow MPI programs doing intra-node communication to do a single copy of the message rather than a double copy of the message via shared memory. The following patch attempts to achieve this by allowing a destination process, given an address and size from a source process, to copy memory directly from the source process into its own address space via a system call. There is also a symmetrical ability to copy from the current process's address space into a destination process's address space. - Use of /proc/pid/mem has been considered, but there are issues with using it: - Does not allow for specifying iovecs for both src and dest, assuming preadv or pwritev was implemented either the area read from or written to would need to be contiguous. - Currently mem_read allows only processes who are currently ptrace'ing the target and are still able to ptrace the target to read from the target. This check could possibly be moved to the open call, but its not clear exactly what race this restriction is stopping (reason appears to have been lost) - Having to send the fd of /proc/self/mem via SCM_RIGHTS on unix domain socket is a bit ugly from a userspace point of view, especially when you may have hundreds if not (eventually) thousands of processes that all need to do this with each other - Doesn't allow for some future use of the interface we would like to consider adding in the future (see below) - Interestingly reading from /proc/pid/mem currently actually involves two copies! (But this could be fixed pretty easily) As mentioned previously use of vmsplice instead was considered, but has problems. Since you need the reader and writer working co-operatively if the pipe is not drained then you block. Which requires some wrapping to do non blocking on the send side or polling on the receive. In all to all communication it requires ordering otherwise you can deadlock. And in the example of many MPI tasks writing to one MPI task vmsplice serialises the copying. There are some cases of MPI collectives where even a single copy interface does not get us the performance gain we could. For example in an MPI_Reduce rather than copy the data from the source we would like to instead use it directly in a mathops (say the reduce is doing a sum) as this would save us doing a copy. We don't need to keep a copy of the data from the source. I haven't implemented this, but I think this interface could in the future do all this through the use of the flags - eg could specify the math operation and type and the kernel rather than just copying the data would apply the specified operation between the source and destination and store it in the destination. Although we don't have a "second user" of the interface (though I've had some nibbles from people who may be interested in using it for intra process messaging which is not MPI). This interface is something which hardware vendors are already doing for their custom drivers to implement fast local communication. And so in addition to this being useful for OpenMPI it would mean the driver maintainers don't have to fix things up when the mm changes. There was some discussion about how much faster a true zero copy would go. Here's a link back to the email with some testing I did on that: http://marc.info/?l=linux-mm&m=130105930902915&w=2 There is a basic man page for the proposed interface here: http://ozlabs.org/~cyeoh/cma/process_vm_readv.txt This has been implemented for x86 and powerpc, other architecture should mainly (I think) just need to add syscall numbers for the process_vm_readv and process_vm_writev. There are 32 bit compatibility versions for 64-bit kernels. For arch maintainers there are some simple tests to be able to quickly verify that the syscalls are working correctly here: http://ozlabs.org/~cyeoh/cma/cma-test-20110718.tgz Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: <linux-man@vger.kernel.org> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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