linux/ipc/mqueue.c, branch v5.1

Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2019-03-12T21:08:19Z

Pull vfs mount infrastructure updates from Al Viro: "The rest of core infrastructure; no new syscalls in that pile, but the old parts are switched to new infrastructure. At that point conversions of individual filesystems can happen independently; some are done here (afs, cgroup, procfs, etc.), there's also a large series outside of that pile dealing with NFS (quite a bit of option-parsing stuff is getting used there - it's one of the most convoluted filesystems in terms of mount-related logics), but NFS bits are the next cycle fodder. It got seriously simplified since the last cycle; documentation is probably the weakest bit at the moment - I considered dropping the commit introducing Documentation/filesystems/mount_api.txt (cutting the size increase by quarter ;-), but decided that it would be better to fix it up after -rc1 instead. That pile allows to do followup work in independent branches, which should make life much easier for the next cycle. fs/super.c size increase is unpleasant; there's a followup series that allows to shrink it considerably, but I decided to leave that until the next cycle" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits) afs: Use fs_context to pass parameters over automount afs: Add fs_context support vfs: Add some logging to the core users of the fs_context log vfs: Implement logging through fs_context vfs: Provide documentation for new mount API vfs: Remove kern_mount_data() hugetlbfs: Convert to fs_context cpuset: Use fs_context kernfs, sysfs, cgroup, intel_rdt: Support fs_context cgroup: store a reference to cgroup_ns into cgroup_fs_context cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper cgroup_do_mount(): massage calling conventions cgroup: stash cgroup_root reference into cgroup_fs_context cgroup2: switch to option-by-option parsing cgroup1: switch to option-by-option parsing cgroup: take options parsing into ->parse_monolithic() cgroup: fold cgroup1_mount() into cgroup1_get_tree() cgroup: start switching to fs_context ipc: Convert mqueue fs to fs_context proc: Add fs_context support to procfs ...

ipc: Convert mqueue fs to fs_context

2019-02-28T08:29:29Z

Convert the mqueue filesystem to use the filesystem context stuff. Notes: (1) The relevant ipc namespace is selected in when the context is initialised (and it defaults to the current task's ipc namespace). The caller can override this before calling vfs_get_tree(). (2) Rather than simply calling kern_mount_data(), mq_init_ns() and mq_internal_mount() create a context, adjust it and then do the rest of the mount procedure. (3) The lazy mqueue mounting on creation of a new namespace is retained from a previous patch, but the avoidance of sget() if no superblock yet exists is reverted and the superblock is again keyed on the namespace pointer. Yes, there was a performance gain in not searching the superblock hash, but it's only paid once per ipc namespace - and only if someone uses mqueue within that namespace, so I'm not sure it's worth it, especially as calling sget() allows avoidance of recursion. Signed-off-by: David Howells Signed-off-by: Al Viro

y2038: syscalls: rename y2038 compat syscalls

2019-02-06T23:13:27Z

A lot of system calls that pass a time_t somewhere have an implementation using a COMPAT_SYSCALL_DEFINEx() on 64-bit architectures, and have been reworked so that this implementation can now be used on 32-bit architectures as well. The missing step is to redefine them using the regular SYSCALL_DEFINEx() to get them out of the compat namespace and make it possible to build them on 32-bit architectures. Any system call that ends in 'time' gets a '32' suffix on its name for that version, while the others get a '_time32' suffix, to distinguish them from the normal version, which takes a 64-bit time argument in the future. In this step, only 64-bit architectures are changed, doing this rename first lets us avoid touching the 32-bit architectures twice. Acked-by: Catalin Marinas Signed-off-by: Arnd Bergmann

Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-10-25T18:14:36Z

Pull timekeeping updates from Thomas Gleixner: "The timers and timekeeping departement provides: - Another large y2038 update with further preparations for providing the y2038 safe timespecs closer to the syscalls. - An overhaul of the SHCMT clocksource driver - SPDX license identifier updates - Small cleanups and fixes all over the place" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (31 commits) tick/sched : Remove redundant cpu_online() check clocksource/drivers/dw_apb: Add reset control clocksource: Remove obsolete CLOCKSOURCE_OF_DECLARE clocksource/drivers: Unify the names to timer-* format clocksource/drivers/sh_cmt: Add R-Car gen3 support dt-bindings: timer: renesas: cmt: document R-Car gen3 support clocksource/drivers/sh_cmt: Properly line-wrap sh_cmt_of_table[] initializer clocksource/drivers/sh_cmt: Fix clocksource width for 32-bit machines clocksource/drivers/sh_cmt: Fixup for 64-bit machines clocksource/drivers/sh_tmu: Convert to SPDX identifiers clocksource/drivers/sh_mtu2: Convert to SPDX identifiers clocksource/drivers/sh_cmt: Convert to SPDX identifiers clocksource/drivers/renesas-ostm: Convert to SPDX identifiers clocksource: Convert to using %pOFn instead of device_node.name tick/broadcast: Remove redundant check RISC-V: Request newstat syscalls y2038: signal: Change rt_sigtimedwait to use __kernel_timespec y2038: socket: Change recvmmsg to use __kernel_timespec y2038: sched: Change sched_rr_get_interval to use __kernel_timespec y2038: utimes: Rework #ifdef guards for compat syscalls ...

signal: Distinguish between kernel_siginfo and siginfo

2018-10-03T14:47:43Z

Linus recently observed that if we did not worry about the padding member in struct siginfo it is only about 48 bytes, and 48 bytes is much nicer than 128 bytes for allocating on the stack and copying around in the kernel. The obvious thing of only adding the padding when userspace is including siginfo.h won't work as there are sigframe definitions in the kernel that embed struct siginfo. So split siginfo in two; kernel_siginfo and siginfo. Keeping the traditional name for the userspace definition. While the version that is used internally to the kernel and ultimately will not be padded to 128 bytes is called kernel_siginfo. The definition of struct kernel_siginfo I have put in include/signal_types.h A set of buildtime checks has been added to verify the two structures have the same field offsets. To make it easy to verify the change kernel_siginfo retains the same size as siginfo. The reduction in size comes in a following change. Signed-off-by: "Eric W. Biederman"

y2038: globally rename compat_time to old_time32

2018-08-27T12:48:48Z

Christoph Hellwig suggested a slightly different path for handling backwards compatibility with the 32-bit time_t based system calls: Rather than simply reusing the compat_sys_* entry points on 32-bit architectures unchanged, we get rid of those entry points and the compat_time types by renaming them to something that makes more sense on 32-bit architectures (which don't have a compat mode otherwise), and then share the entry points under the new name with the 64-bit architectures that use them for implementing the compatibility. The following types and interfaces are renamed here, and moved from linux/compat_time.h to linux/time32.h: old new --- --- compat_time_t old_time32_t struct compat_timeval struct old_timeval32 struct compat_timespec struct old_timespec32 struct compat_itimerspec struct old_itimerspec32 ns_to_compat_timeval() ns_to_old_timeval32() get_compat_itimerspec64() get_old_itimerspec32() put_compat_itimerspec64() put_old_itimerspec32() compat_get_timespec64() get_old_timespec32() compat_put_timespec64() put_old_timespec32() As we already have aliases in place, this patch addresses only the instances that are relevant to the system call interface in particular, not those that occur in device drivers and other modules. Those will get handled separately, while providing the 64-bit version of the respective interfaces. I'm not renaming the timex, rusage and itimerval structures, as we are still debating what the new interface will look like, and whether we will need a replacement at all. This also doesn't change the names of the syscall entry points, which can be done more easily when we actually switch over the 32-bit architectures to use them, at that point we need to change COMPAT_SYSCALL_DEFINEx to SYSCALL_DEFINEx with a new name, e.g. with a _time32 suffix. Suggested-by: Christoph Hellwig Link: https://lore.kernel.org/lkml/20180705222110.GA5698@infradead.org/ Signed-off-by: Arnd Bergmann

y2038: ipc: Enable COMPAT_32BIT_TIME

2018-04-20T14:20:27Z

Three ipc syscalls (mq_timedsend, mq_timedreceive and and semtimedop) take a timespec argument. After we move 32-bit architectures over to useing 64-bit time_t based syscalls, we need seperate entry points for the old 32-bit based interfaces. This changes the #ifdef guards for the existing 32-bit compat syscalls to check for CONFIG_COMPAT_32BIT_TIME instead, which will then be enabled on all existing 32-bit architectures. Signed-off-by: Arnd Bergmann

y2038: ipc: Use __kernel_timespec

2018-04-20T14:20:24Z

This is a preparatation for changing over __kernel_timespec to 64-bit times, which involves assigning new system call numbers for mq_timedsend(), mq_timedreceive() and semtimedop() for compatibility with future y2038 proof user space. The existing ABIs will remain available through compat code. Signed-off-by: Arnd Bergmann

Revert "mqueue: switch to on-demand creation of internal mount"

2018-03-25T00:34:23Z

This reverts commit 36735a6a2b5e042db1af956ce4bcc13f3ff99e21. Aleksa Sarai writes: > [REGRESSION v4.16-rc6] [PATCH] mqueue: forbid unprivileged user access to internal mount > > Felix reported weird behaviour on 4.16.0-rc6 with regards to mqueue[1], > which was introduced by 36735a6a2b5e ("mqueue: switch to on-demand > creation of internal mount"). > > Basically, the reproducer boils down to being able to mount mqueue if > you create a new user namespace, even if you don't unshare the IPC > namespace. > > Previously this was not possible, and you would get an -EPERM. The mount > is the *host* mqueue mount, which is being cached and just returned from > mqueue_mount(). To be honest, I'm not sure if this is safe or not (or if > it was intentional -- since I'm not familiar with mqueue). > > To me it looks like there is a missing permission check. I've included a > patch below that I've compile-tested, and should block the above case. > Can someone please tell me if I'm missing something? Is this actually > safe? > > [1]: https://github.com/docker/docker/issues/36674 The issue is a lot deeper than a missing permission check. sb->s_user_ns was is improperly set as well. So in addition to the filesystem being mounted when it should not be mounted, so things are not allow that should be. We are practically to the release of 4.16 and there is no agreement between Al Viro and myself on what the code should looks like to fix things properly. So revert the code to what it was before so that we can take our time and discuss this properly. Fixes: 36735a6a2b5e ("mqueue: switch to on-demand creation of internal mount") Reported-by: Felix Abecassis Reported-by: Aleksa Sarai Signed-off-by: "Eric W. Biederman"

vfs: do bulk POLL* -> EPOLL* replacement

2018-02-11T22:34:03Z

This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^$[^\"]*$$\$/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro Signed-off-by: Linus Torvalds