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* mm: treewide: remove GFP_TEMPORARY allocation flagMichal Hocko2017-09-141-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | GFP_TEMPORARY was introduced by commit e12ba74d8ff3 ("Group short-lived and reclaimable kernel allocations") along with __GFP_RECLAIMABLE. It's primary motivation was to allow users to tell that an allocation is short lived and so the allocator can try to place such allocations close together and prevent long term fragmentation. As much as this sounds like a reasonable semantic it becomes much less clear when to use the highlevel GFP_TEMPORARY allocation flag. How long is temporary? Can the context holding that memory sleep? Can it take locks? It seems there is no good answer for those questions. The current implementation of GFP_TEMPORARY is basically GFP_KERNEL | __GFP_RECLAIMABLE which in itself is tricky because basically none of the existing caller provide a way to reclaim the allocated memory. So this is rather misleading and hard to evaluate for any benefits. I have checked some random users and none of them has added the flag with a specific justification. I suspect most of them just copied from other existing users and others just thought it might be a good idea to use without any measuring. This suggests that GFP_TEMPORARY just motivates for cargo cult usage without any reasoning. I believe that our gfp flags are quite complex already and especially those with highlevel semantic should be clearly defined to prevent from confusion and abuse. Therefore I propose dropping GFP_TEMPORARY and replace all existing users to simply use GFP_KERNEL. Please note that SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and so they will be placed properly for memory fragmentation prevention. I can see reasons we might want some gfp flag to reflect shorterm allocations but I propose starting from a clear semantic definition and only then add users with proper justification. This was been brought up before LSF this year by Matthew [1] and it turned out that GFP_TEMPORARY really doesn't have a clear semantic. It seems to be a heuristic without any measured advantage for most (if not all) its current users. The follow up discussion has revealed that opinions on what might be temporary allocation differ a lot between developers. So rather than trying to tweak existing users into a semantic which they haven't expected I propose to simply remove the flag and start from scratch if we really need a semantic for short term allocations. [1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org [akpm@linux-foundation.org: fix typo] [akpm@linux-foundation.org: coding-style fixes] [sfr@canb.auug.org.au: drm/i915: fix up] Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Matthew Wilcox <willy@infradead.org> Cc: Neil Brown <neilb@suse.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: add /proc/pid/smaps_rollupDaniel Colascione2017-09-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | /proc/pid/smaps_rollup is a new proc file that improves the performance of user programs that determine aggregate memory statistics (e.g., total PSS) of a process. Android regularly "samples" the memory usage of various processes in order to balance its memory pool sizes. This sampling process involves opening /proc/pid/smaps and summing certain fields. For very large processes, sampling memory use this way can take several hundred milliseconds, due mostly to the overhead of the seq_printf calls in task_mmu.c. smaps_rollup improves the situation. It contains most of the fields of /proc/pid/smaps, but instead of a set of fields for each VMA, smaps_rollup instead contains one synthetic smaps-format entry representing the whole process. In the single smaps_rollup synthetic entry, each field is the summation of the corresponding field in all of the real-smaps VMAs. Using a common format for smaps_rollup and smaps allows userspace parsers to repurpose parsers meant for use with non-rollup smaps for smaps_rollup, and it allows userspace to switch between smaps_rollup and smaps at runtime (say, based on the availability of smaps_rollup in a given kernel) with minimal fuss. By using smaps_rollup instead of smaps, a caller can avoid the significant overhead of formatting, reading, and parsing each of a large process's potentially very numerous memory mappings. For sampling system_server's PSS in Android, we measured a 12x speedup, representing a savings of several hundred milliseconds. One alternative to a new per-process proc file would have been including PSS information in /proc/pid/status. We considered this option but thought that PSS would be too expensive (by a few orders of magnitude) to collect relative to what's already emitted as part of /proc/pid/status, and slowing every user of /proc/pid/status for the sake of readers that happen to want PSS feels wrong. The code itself works by reusing the existing VMA-walking framework we use for regular smaps generation and keeping the mem_size_stats structure around between VMA walks instead of using a fresh one for each VMA. In this way, summation happens automatically. We let seq_file walk over the VMAs just as it does for regular smaps and just emit nothing to the seq_file until we hit the last VMA. Benchmarks: using smaps: iterations:1000 pid:1163 pss:220023808 0m29.46s real 0m08.28s user 0m20.98s system using smaps_rollup: iterations:1000 pid:1163 pss:220702720 0m04.39s real 0m00.03s user 0m04.31s system We're using the PSS samples we collect asynchronously for system-management tasks like fine-tuning oom_adj_score, memory use tracking for debugging, application-level memory-use attribution, and deciding whether we want to kill large processes during system idle maintenance windows. Android has been using PSS for these purposes for a long time; as the average process VMA count has increased and and devices become more efficiency-conscious, PSS-collection inefficiency has started to matter more. IMHO, it'd be a lot safer to optimize the existing PSS-collection model, which has been fine-tuned over the years, instead of changing the memory tracking approach entirely to work around smaps-generation inefficiency. Tim said: : There are two main reasons why Android gathers PSS information: : : 1. Android devices can show the user the amount of memory used per : application via the settings app. This is a less important use case. : : 2. We log PSS to help identify leaks in applications. We have found : an enormous number of bugs (in the Android platform, in Google's own : apps, and in third-party applications) using this data. : : To do this, system_server (the main process in Android userspace) will : sample the PSS of a process three seconds after it changes state (for : example, app is launched and becomes the foreground application) and about : every ten minutes after that. The net result is that PSS collection is : regularly running on at least one process in the system (usually a few : times a minute while the screen is on, less when screen is off due to : suspend). PSS of a process is an incredibly useful stat to track, and we : aren't going to get rid of it. We've looked at some very hacky approaches : using RSS ("take the RSS of the target process, subtract the RSS of the : zygote process that is the parent of all Android apps") to reduce the : accounting time, but it regularly overestimated the memory used by 20+ : percent. Accordingly, I don't think that there's a good alternative to : using PSS. : : We started looking into PSS collection performance after we noticed random : frequency spikes while a phone's screen was off; occasionally, one of the : CPU clusters would ramp to a high frequency because there was 200-300ms of : constant CPU work from a single thread in the main Android userspace : process. The work causing the spike (which is reasonable governor : behavior given the amount of CPU time needed) was always PSS collection. : As a result, Android is burning more power than we should be on PSS : collection. : : The other issue (and why I'm less sure about improving smaps as a : long-term solution) is that the number of VMAs per process has increased : significantly from release to release. After trying to figure out why we : were seeing these 200-300ms PSS collection times on Android O but had not : noticed it in previous versions, we found that the number of VMAs in the : main system process increased by 50% from Android N to Android O (from : ~1800 to ~2700) and varying increases in every userspace process. Android : M to N also had an increase in the number of VMAs, although not as much. : I'm not sure why this is increasing so much over time, but thinking about : ASLR and ways to make ASLR better, I expect that this will continue to : increase going forward. I would not be surprised if we hit 5000 VMAs on : the main Android process (system_server) by 2020. : : If we assume that the number of VMAs is going to increase over time, then : doing anything we can do to reduce the overhead of each VMA during PSS : collection seems like the right way to go, and that means outputting an : aggregate statistic (to avoid whatever overhead there is per line in : writing smaps and in reading each line from userspace). Link: http://lkml.kernel.org/r/20170812022148.178293-1-dancol@google.com Signed-off-by: Daniel Colascione <dancol@google.com> Cc: Tim Murray <timmurray@google.com> Cc: Joel Fernandes <joelaf@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sonny Rao <sonnyrao@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sched/debug: Use task_pid_nr_ns in /proc/$pid/schedAleksa Sarai2017-08-101-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It appears as though the addition of the PID namespace did not update the output code for /proc/*/sched, which resulted in it providing PIDs that were not self-consistent with the /proc mount. This additionally made it trivial to detect whether a process was inside &init_pid_ns from userspace, making container detection trivial: https://github.com/jessfraz/amicontained This leads to situations such as: % unshare -pmf % mount -t proc proc /proc % head -n1 /proc/1/sched head (10047, #threads: 1) Fix this by just using task_pid_nr_ns for the output of /proc/*/sched. All of the other uses of task_pid_nr in kernel/sched/debug.c are from a sysctl context and thus don't need to be namespaced. Signed-off-by: Aleksa Sarai <asarai@suse.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Jess Frazelle <acidburn@google.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: cyphar@cyphar.com Link: http://lkml.kernel.org/r/20170806044141.5093-1-asarai@suse.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* fault-inject: add /proc/<pid>/fail-nthAkinobu Mita2017-07-151-0/+1
| | | | | | | | | | | | | | | fail-nth interface is only created in /proc/self/task/<current-tid>/. This change also adds it in /proc/<pid>/. This makes shell based tool a bit simpler. $ bash -c "builtin echo 100 > /proc/self/fail-nth && exec ls /" Link: http://lkml.kernel.org/r/1491490561-10485-6-git-send-email-akinobu.mita@gmail.com Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-inject: simplify access check for fail-nthAkinobu Mita2017-07-151-15/+10Star
| | | | | | | | | | | | | | | | | | | The fail-nth file is created with 0666 and the access is permitted if and only if the task is current. This file is owned by the currnet user. So we can create it with 0644 and allow the owner to write it. This enables to watch the status of task->fail_nth from another processes. [akinobu.mita@gmail.com: don't convert unsigned type value as signed int] Link: http://lkml.kernel.org/r/1492444483-9239-1-git-send-email-akinobu.mita@gmail.com [akinobu.mita@gmail.com: avoid unwanted data race to task->fail_nth] Link: http://lkml.kernel.org/r/1499962492-8931-1-git-send-email-akinobu.mita@gmail.com Link: http://lkml.kernel.org/r/1491490561-10485-5-git-send-email-akinobu.mita@gmail.com Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-inject: make fail-nth read/write interface symmetricAkinobu Mita2017-07-151-8/+6Star
| | | | | | | | | | | | | | | | The read interface for fail-nth looks a bit odd. Read from this file returns "NYYYY..." or "YYYYY..." (this makes me surprise when cat this file). Because there is no EOF condition. The first character indicates current->fail_nth is zero or not, and then current->fail_nth is reset to zero. Just returning task->fail_nth value is more natural to understand. Link: http://lkml.kernel.org/r/1491490561-10485-4-git-send-email-akinobu.mita@gmail.com Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-inject: parse as natural 1-based value for fail-nth write interfaceAkinobu Mita2017-07-151-5/+4Star
| | | | | | | | | | | | | | The value written to fail-nth file is parsed as 0-based. Parsing as one-based is more natural to understand and it enables to cancel the previous setup by simply writing '0'. This change also converts task->fail_nth from signed to unsigned int. Link: http://lkml.kernel.org/r/1491490561-10485-3-git-send-email-akinobu.mita@gmail.com Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-inject: automatically detect the number base for fail-nth write interfaceAkinobu Mita2017-07-151-1/+1
| | | | | | | | | | | Automatically detect the number base to use when writing to fail-nth file instead of always parsing as a decimal number. Link: http://lkml.kernel.org/r/1491490561-10485-2-git-send-email-akinobu.mita@gmail.com Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fault-inject: support systematic fault injectionDmitry Vyukov2017-07-131-0/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add /proc/self/task/<current-tid>/fail-nth file that allows failing 0-th, 1-st, 2-nd and so on calls systematically. Excerpt from the added documentation: "Write to this file of integer N makes N-th call in the current task fail (N is 0-based). Read from this file returns a single char 'Y' or 'N' that says if the fault setup with a previous write to this file was injected or not, and disables the fault if it wasn't yet injected. Note that this file enables all types of faults (slab, futex, etc). This setting takes precedence over all other generic settings like probability, interval, times, etc. But per-capability settings (e.g. fail_futex/ignore-private) take precedence over it. This feature is intended for systematic testing of faults in a single system call. See an example below" Why add a new setting: 1. Existing settings are global rather than per-task. So parallel testing is not possible. 2. attr->interval is close but it depends on attr->count which is non reset to 0, so interval does not work as expected. 3. Trying to model this with existing settings requires manipulations of all of probability, interval, times, space, task-filter and unexposed count and per-task make-it-fail files. 4. Existing settings are per-failure-type, and the set of failure types is potentially expanding. 5. make-it-fail can't be changed by unprivileged user and aggressive stress testing better be done from an unprivileged user. Similarly, this would require opening the debugfs files to the unprivileged user, as he would need to reopen at least times file (not possible to pre-open before dropping privs). The proposed interface solves all of the above (see the example). We want to integrate this into syzkaller fuzzer. A prototype has found 10 bugs in kernel in first day of usage: https://groups.google.com/forum/#!searchin/syzkaller/%22FAULT_INJECTION%22%7Csort:relevance I've made the current interface work with all types of our sandboxes. For setuid the secret sauce was prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) to make /proc entries non-root owned. So I am fine with the current version of the code. [akpm@linux-foundation.org: fix build] Link: http://lkml.kernel.org/r/20170328130128.101773-1-dvyukov@google.com Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* "Yes, people use FOLL_FORCE ;)"Linus Torvalds2017-05-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This effectively reverts commit 8ee74a91ac30 ("proc: try to remove use of FOLL_FORCE entirely") It turns out that people do depend on FOLL_FORCE for the /proc/<pid>/mem case, and we're talking not just debuggers. Talking to the affected people, the use-cases are: Keno Fischer: "We used these semantics as a hardening mechanism in the julia JIT. By opening /proc/self/mem and using these semantics, we could avoid needing RWX pages, or a dual mapping approach. We do have fallbacks to these other methods (though getting EIO here actually causes an assert in released versions - we'll updated that to make sure to take the fall back in that case). Nevertheless the /proc/self/mem approach was our favored approach because it a) Required an attacker to be able to execute syscalls which is a taller order than getting memory write and b) didn't double the virtual address space requirements (as a dual mapping approach would). I think in general this feature is very useful for anybody who needs to precisely control the execution of some other process. Various debuggers (gdb/lldb/rr) certainly fall into that category, but there's another class of such processes (wine, various emulators) which may want to do that kind of thing. Now, I suspect most of these will have the other process under ptrace control, so maybe allowing (same_mm || ptraced) would be ok, but at least for the sandbox/remote-jit use case, it would be perfectly reasonable to not have the jit server be a ptracer" Robert O'Callahan: "We write to readonly code and data mappings via /proc/.../mem in lots of different situations, particularly when we're adjusting program state during replay to match the recorded execution. Like Julia, we can add workarounds, but they could be expensive." so not only do people use FOLL_FORCE for both reads and writes, but they use it for both the local mm and remote mm. With these comments in mind, we likely also cannot add the "are we actively ptracing" check either, so this keeps the new code organization and does not do a real revert that would add back the original comment about "Maybe we should limit FOLL_FORCE to actual ptrace users?" Reported-by: Keno Fischer <keno@juliacomputing.com> Reported-by: Robert O'Callahan <robert@ocallahan.org> Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: try to remove use of FOLL_FORCE entirelyLinus Torvalds2017-05-091-4/+1Star
| | | | | | | | | | | | | | | | | | | | | | We fixed the bugs in it, but it's still an ugly interface, so let's see if anybody actually depends on it. It's entirely possible that nothing actually requires the whole "punch through read-only mappings" semantics. For example, gdb definitely uses the /proc/<pid>/mem interface, but it looks like it mainly does it for regular reads of the target (that don't need FOLL_FORCE), and looking at the gdb source code seems to fall back on the traditional ptrace(PTRACE_POKEDATA) interface if it needs to. If this breaks something, I do have a (more complex) version that only enables FOLL_FORCE when somebody has PTRACE_ATTACH'ed to the target, like the comment here used to say ("Maybe we should limit FOLL_FORCE to actual ptrace users?"). Cc: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* livepatch: add /proc/<pid>/patch_stateJosh Poimboeuf2017-03-081-0/+15
| | | | | | | | | | Expose the per-task patch state value so users can determine which tasks are holding up completion of a patching operation. Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Reviewed-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* Merge branch 'rebased-statx' of ↵Linus Torvalds2017-03-031-5/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs 'statx()' update from Al Viro. This adds the new extended stat() interface that internally subsumes our previous stat interfaces, and allows user mode to specify in more detail what kind of information it wants. It also allows for some explicit synchronization information to be passed to the filesystem, which can be relevant for network filesystems: is the cached value ok, or do you need open/close consistency, or what? From David Howells. Andreas Dilger points out that the first version of the extended statx interface was posted June 29, 2010: https://www.spinics.net/lists/linux-fsdevel/msg33831.html * 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: statx: Add a system call to make enhanced file info available
| * statx: Add a system call to make enhanced file info availableDavid Howells2017-03-031-5/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a system call to make extended file information available, including file creation and some attribute flags where available through the underlying filesystem. The getattr inode operation is altered to take two additional arguments: a u32 request_mask and an unsigned int flags that indicate the synchronisation mode. This change is propagated to the vfs_getattr*() function. Functions like vfs_stat() are now inline wrappers around new functions vfs_statx() and vfs_statx_fd() to reduce stack usage. ======== OVERVIEW ======== The idea was initially proposed as a set of xattrs that could be retrieved with getxattr(), but the general preference proved to be for a new syscall with an extended stat structure. A number of requests were gathered for features to be included. The following have been included: (1) Make the fields a consistent size on all arches and make them large. (2) Spare space, request flags and information flags are provided for future expansion. (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an __s64). (4) Creation time: The SMB protocol carries the creation time, which could be exported by Samba, which will in turn help CIFS make use of FS-Cache as that can be used for coherency data (stx_btime). This is also specified in NFSv4 as a recommended attribute and could be exported by NFSD [Steve French]. (5) Lightweight stat: Ask for just those details of interest, and allow a netfs (such as NFS) to approximate anything not of interest, possibly without going to the server [Trond Myklebust, Ulrich Drepper, Andreas Dilger] (AT_STATX_DONT_SYNC). (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks its cached attributes are up to date [Trond Myklebust] (AT_STATX_FORCE_SYNC). And the following have been left out for future extension: (7) Data version number: Could be used by userspace NFS servers [Aneesh Kumar]. Can also be used to modify fill_post_wcc() in NFSD which retrieves i_version directly, but has just called vfs_getattr(). It could get it from the kstat struct if it used vfs_xgetattr() instead. (There's disagreement on the exact semantics of a single field, since not all filesystems do this the same way). (8) BSD stat compatibility: Including more fields from the BSD stat such as creation time (st_btime) and inode generation number (st_gen) [Jeremy Allison, Bernd Schubert]. (9) Inode generation number: Useful for FUSE and userspace NFS servers [Bernd Schubert]. (This was asked for but later deemed unnecessary with the open-by-handle capability available and caused disagreement as to whether it's a security hole or not). (10) Extra coherency data may be useful in making backups [Andreas Dilger]. (No particular data were offered, but things like last backup timestamp, the data version number and the DOS archive bit would come into this category). (11) Allow the filesystem to indicate what it can/cannot provide: A filesystem can now say it doesn't support a standard stat feature if that isn't available, so if, for instance, inode numbers or UIDs don't exist or are fabricated locally... (This requires a separate system call - I have an fsinfo() call idea for this). (12) Store a 16-byte volume ID in the superblock that can be returned in struct xstat [Steve French]. (Deferred to fsinfo). (13) Include granularity fields in the time data to indicate the granularity of each of the times (NFSv4 time_delta) [Steve French]. (Deferred to fsinfo). (14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags. Note that the Linux IOC flags are a mess and filesystems such as Ext4 define flags that aren't in linux/fs.h, so translation in the kernel may be a necessity (or, possibly, we provide the filesystem type too). (Some attributes are made available in stx_attributes, but the general feeling was that the IOC flags were to ext[234]-specific and shouldn't be exposed through statx this way). (15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer, Michael Kerrisk]. (Deferred, probably to fsinfo. Finding out if there's an ACL or seclabal might require extra filesystem operations). (16) Femtosecond-resolution timestamps [Dave Chinner]. (A __reserved field has been left in the statx_timestamp struct for this - if there proves to be a need). (17) A set multiple attributes syscall to go with this. =============== NEW SYSTEM CALL =============== The new system call is: int ret = statx(int dfd, const char *filename, unsigned int flags, unsigned int mask, struct statx *buffer); The dfd, filename and flags parameters indicate the file to query, in a similar way to fstatat(). There is no equivalent of lstat() as that can be emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is also no equivalent of fstat() as that can be emulated by passing a NULL filename to statx() with the fd of interest in dfd. Whether or not statx() synchronises the attributes with the backing store can be controlled by OR'ing a value into the flags argument (this typically only affects network filesystems): (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this respect. (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise its attributes with the server - which might require data writeback to occur to get the timestamps correct. (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a network filesystem. The resulting values should be considered approximate. mask is a bitmask indicating the fields in struct statx that are of interest to the caller. The user should set this to STATX_BASIC_STATS to get the basic set returned by stat(). It should be noted that asking for more information may entail extra I/O operations. buffer points to the destination for the data. This must be 256 bytes in size. ====================== MAIN ATTRIBUTES RECORD ====================== The following structures are defined in which to return the main attribute set: struct statx_timestamp { __s64 tv_sec; __s32 tv_nsec; __s32 __reserved; }; struct statx { __u32 stx_mask; __u32 stx_blksize; __u64 stx_attributes; __u32 stx_nlink; __u32 stx_uid; __u32 stx_gid; __u16 stx_mode; __u16 __spare0[1]; __u64 stx_ino; __u64 stx_size; __u64 stx_blocks; __u64 __spare1[1]; struct statx_timestamp stx_atime; struct statx_timestamp stx_btime; struct statx_timestamp stx_ctime; struct statx_timestamp stx_mtime; __u32 stx_rdev_major; __u32 stx_rdev_minor; __u32 stx_dev_major; __u32 stx_dev_minor; __u64 __spare2[14]; }; The defined bits in request_mask and stx_mask are: STATX_TYPE Want/got stx_mode & S_IFMT STATX_MODE Want/got stx_mode & ~S_IFMT STATX_NLINK Want/got stx_nlink STATX_UID Want/got stx_uid STATX_GID Want/got stx_gid STATX_ATIME Want/got stx_atime{,_ns} STATX_MTIME Want/got stx_mtime{,_ns} STATX_CTIME Want/got stx_ctime{,_ns} STATX_INO Want/got stx_ino STATX_SIZE Want/got stx_size STATX_BLOCKS Want/got stx_blocks STATX_BASIC_STATS [The stuff in the normal stat struct] STATX_BTIME Want/got stx_btime{,_ns} STATX_ALL [All currently available stuff] stx_btime is the file creation time, stx_mask is a bitmask indicating the data provided and __spares*[] are where as-yet undefined fields can be placed. Time fields are structures with separate seconds and nanoseconds fields plus a reserved field in case we want to add even finer resolution. Note that times will be negative if before 1970; in such a case, the nanosecond fields will also be negative if not zero. The bits defined in the stx_attributes field convey information about a file, how it is accessed, where it is and what it does. The following attributes map to FS_*_FL flags and are the same numerical value: STATX_ATTR_COMPRESSED File is compressed by the fs STATX_ATTR_IMMUTABLE File is marked immutable STATX_ATTR_APPEND File is append-only STATX_ATTR_NODUMP File is not to be dumped STATX_ATTR_ENCRYPTED File requires key to decrypt in fs Within the kernel, the supported flags are listed by: KSTAT_ATTR_FS_IOC_FLAGS [Are any other IOC flags of sufficient general interest to be exposed through this interface?] New flags include: STATX_ATTR_AUTOMOUNT Object is an automount trigger These are for the use of GUI tools that might want to mark files specially, depending on what they are. Fields in struct statx come in a number of classes: (0) stx_dev_*, stx_blksize. These are local system information and are always available. (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino, stx_size, stx_blocks. These will be returned whether the caller asks for them or not. The corresponding bits in stx_mask will be set to indicate whether they actually have valid values. If the caller didn't ask for them, then they may be approximated. For example, NFS won't waste any time updating them from the server, unless as a byproduct of updating something requested. If the values don't actually exist for the underlying object (such as UID or GID on a DOS file), then the bit won't be set in the stx_mask, even if the caller asked for the value. In such a case, the returned value will be a fabrication. Note that there are instances where the type might not be valid, for instance Windows reparse points. (2) stx_rdev_*. This will be set only if stx_mode indicates we're looking at a blockdev or a chardev, otherwise will be 0. (3) stx_btime. Similar to (1), except this will be set to 0 if it doesn't exist. ======= TESTING ======= The following test program can be used to test the statx system call: samples/statx/test-statx.c Just compile and run, passing it paths to the files you want to examine. The file is built automatically if CONFIG_SAMPLES is enabled. Here's some example output. Firstly, an NFS directory that crosses to another FSID. Note that the AUTOMOUNT attribute is set because transiting this directory will cause d_automount to be invoked by the VFS. [root@andromeda ~]# /tmp/test-statx -A /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:26 Inode: 1703937 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------) Secondly, the result of automounting on that directory. [root@andromeda ~]# /tmp/test-statx /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:27 Inode: 2 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | sched/headers: Prepare to move sched_info_on() and force_schedstat_enabled() ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | from <linux/sched.h> to <linux/sched/stat.h> But first update usage sites with the new header dependency. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | <linux/sched/debug.h> We are going to split <linux/sched/debug.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/debug.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | <linux/sched/coredump.h> We are going to split <linux/sched/coredump.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/coredump.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | <linux/sched/mm.h> We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
|/ | | | | | | | | | | | | | | | | | | | <linux/sched/autogroup.h> We are going to split <linux/sched/autogroup.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/autogroup.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* mm: use mmget_not_zero() helperVegard Nossum2017-02-281-2/+2
| | | | | | | | | | | | | | | | | | We already have the helper, we can convert the rest of the kernel mechanically using: git grep -l 'atomic_inc_not_zero.*mm_users' | xargs sed -i 's/atomic_inc_not_zero(&\(.*\)->mm_users)/mmget_not_zero\(\1\)/' This is needed for a later patch that hooks into the helper, but might be a worthwhile cleanup on its own. Link: http://lkml.kernel.org/r/20161218123229.22952-3-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: add new mmgrab() helperVegard Nossum2017-02-281-2/+2
| | | | | | | | | | | | | | | | | | | | | Apart from adding the helper function itself, the rest of the kernel is converted mechanically using: git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)->mm_count);/mmgrab\(\1\);/' git grep -l 'atomic_inc.*mm_count' | xargs sed -i 's/atomic_inc(&\(.*\)\.mm_count);/mmgrab\(\&\1\);/' This is needed for a later patch that hooks into the helper, but might be a worthwhile cleanup on its own. (Michal Hocko provided most of the kerneldoc comment.) Link: http://lkml.kernel.org/r/20161218123229.22952-1-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* procfs: use an enum for possible hidepid valuesLafcadio Wluiki2017-02-251-4/+4
| | | | | | | | | | | | | | | | | | | | | | Previously, the hidepid parameter was checked by comparing literal integers 0, 1, 2. Let's add a proper enum for this, to make the checking more expressive: 0 → HIDEPID_OFF 1 → HIDEPID_NO_ACCESS 2 → HIDEPID_INVISIBLE This changes the internal labelling only, the userspace-facing interface remains unmodified, and still works with literal integers 0, 1, 2. No functional changes. Link: http://lkml.kernel.org/r/1484572984-13388-2-git-send-email-djalal@gmail.com Signed-off-by: Lafcadio Wluiki <wluikil@gmail.com> Signed-off-by: Djalal Harouni <tixxdz@gmail.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc: less code duplication in /proc/*/cmdlineAlexey Dobriyan2017-02-251-88/+56Star
| | | | | | | | | | | After staring at this code for a while I've figured using small 2-entry array describing ARGV and ENVP is the way to address code duplication critique. Link: http://lkml.kernel.org/r/20170105185724.GA12027@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2017-02-241-44/+58
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull namespace updates from Eric Biederman: "There is a lot here. A lot of these changes result in subtle user visible differences in kernel behavior. I don't expect anything will care but I will revert/fix things immediately if any regressions show up. From Seth Forshee there is a continuation of the work to make the vfs ready for unpriviled mounts. We had thought the previous changes prevented the creation of files outside of s_user_ns of a filesystem, but it turns we missed the O_CREAT path. Ooops. Pavel Tikhomirov and Oleg Nesterov worked together to fix a long standing bug in the implemenation of PR_SET_CHILD_SUBREAPER where only children that are forked after the prctl are considered and not children forked before the prctl. The only known user of this prctl systemd forks all children after the prctl. So no userspace regressions will occur. Holding earlier forked children to the same rules as later forked children creates a semantic that is sane enough to allow checkpoing of processes that use this feature. There is a long delayed change by Nikolay Borisov to limit inotify instances inside a user namespace. Michael Kerrisk extends the API for files used to maniuplate namespaces with two new trivial ioctls to allow discovery of the hierachy and properties of namespaces. Konstantin Khlebnikov with the help of Al Viro adds code that when a network namespace exits purges it's sysctl entries from the dcache. As in some circumstances this could use a lot of memory. Vivek Goyal fixed a bug with stacked filesystems where the permissions on the wrong inode were being checked. I continue previous work on ptracing across exec. Allowing a file to be setuid across exec while being ptraced if the tracer has enough credentials in the user namespace, and if the process has CAP_SETUID in it's own namespace. Proc files for setuid or otherwise undumpable executables are now owned by the root in the user namespace of their mm. Allowing debugging of setuid applications in containers to work better. A bug I introduced with permission checking and automount is now fixed. The big change is to mark the mounts that the kernel initiates as a result of an automount. This allows the permission checks in sget to be safely suppressed for this kind of mount. As the permission check happened when the original filesystem was mounted. Finally a special case in the mount namespace is removed preventing unbounded chains in the mount hash table, and making the semantics simpler which benefits CRIU. The vfs fix along with related work in ima and evm I believe makes us ready to finish developing and merge fully unprivileged mounts of the fuse filesystem. The cleanups of the mount namespace makes discussing how to fix the worst case complexity of umount. The stacked filesystem fixes pave the way for adding multiple mappings for the filesystem uids so that efficient and safer containers can be implemented" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc/sysctl: Don't grab i_lock under sysctl_lock. vfs: Use upper filesystem inode in bprm_fill_uid() proc/sysctl: prune stale dentries during unregistering mnt: Tuck mounts under others instead of creating shadow/side mounts. prctl: propagate has_child_subreaper flag to every descendant introduce the walk_process_tree() helper nsfs: Add an ioctl() to return owner UID of a userns fs: Better permission checking for submounts exit: fix the setns() && PR_SET_CHILD_SUBREAPER interaction vfs: open() with O_CREAT should not create inodes with unknown ids nsfs: Add an ioctl() to return the namespace type proc: Better ownership of files for non-dumpable tasks in user namespaces exec: Remove LSM_UNSAFE_PTRACE_CAP exec: Test the ptracer's saved cred to see if the tracee can gain caps exec: Don't reset euid and egid when the tracee has CAP_SETUID inotify: Convert to using per-namespace limits
| * proc: Better ownership of files for non-dumpable tasks in user namespacesEric W. Biederman2017-01-241-44/+58
| | | | | | | | | | | | | | | | | | Instead of making the files owned by the GLOBAL_ROOT_USER. Make non-dumpable files whose mm has always lived in a user namespace owned by the user namespace root. This allows the container root to have things work as expected in a container. Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
* | Merge branch 'next' of ↵Linus Torvalds2017-02-211-4/+9
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security layer updates from James Morris: "Highlights: - major AppArmor update: policy namespaces & lots of fixes - add /sys/kernel/security/lsm node for easy detection of loaded LSMs - SELinux cgroupfs labeling support - SELinux context mounts on tmpfs, ramfs, devpts within user namespaces - improved TPM 2.0 support" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (117 commits) tpm: declare tpm2_get_pcr_allocation() as static tpm: Fix expected number of response bytes of TPM1.2 PCR Extend tpm xen: drop unneeded chip variable tpm: fix misspelled "facilitate" in module parameter description tpm_tis: fix the error handling of init_tis() KEYS: Use memzero_explicit() for secret data KEYS: Fix an error code in request_master_key() sign-file: fix build error in sign-file.c with libressl selinux: allow changing labels for cgroupfs selinux: fix off-by-one in setprocattr tpm: silence an array overflow warning tpm: fix the type of owned field in cap_t tpm: add securityfs support for TPM 2.0 firmware event log tpm: enhance read_log_of() to support Physical TPM event log tpm: enhance TPM 2.0 PCR extend to support multiple banks tpm: implement TPM 2.0 capability to get active PCR banks tpm: fix RC value check in tpm2_seal_trusted tpm_tis: fix iTPM probe via probe_itpm() function tpm: Begin the process to deprecate user_read_timer tpm: remove tpm_read_index and tpm_write_index from tpm.h ...
| * | proc,security: move restriction on writing /proc/pid/attr nodes to procStephen Smalley2017-01-091-4/+9
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Processes can only alter their own security attributes via /proc/pid/attr nodes. This is presently enforced by each individual security module and is also imposed by the Linux credentials implementation, which only allows a task to alter its own credentials. Move the check enforcing this restriction from the individual security modules to proc_pid_attr_write() before calling the security hook, and drop the unnecessary task argument to the security hook since it can only ever be the current task. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* | Merge branch 'timers-core-for-linus' of ↵Linus Torvalds2017-02-201-2/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer updates from Thomas Gleixner: "Nothing exciting, just the usual pile of fixes, updates and cleanups: - A bunch of clocksource driver updates - Removal of CONFIG_TIMER_STATS and the related /proc file - More posix timer slim down work - A scalability enhancement in the tick broadcast code - Math cleanups" * 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) hrtimer: Catch invalid clockids again math64, tile: Fix build failure clocksource/drivers/arm_arch_timer:: Mark cyclecounter __ro_after_init timerfd: Protect the might cancel mechanism proper timer_list: Remove useless cast when printing time: Remove CONFIG_TIMER_STATS clocksource/drivers/arm_arch_timer: Work around Hisilicon erratum 161010101 clocksource/drivers/arm_arch_timer: Introduce generic errata handling infrastructure clocksource/drivers/arm_arch_timer: Remove fsl-a008585 parameter clocksource/drivers/arm_arch_timer: Add dt binding for hisilicon-161010101 erratum clocksource/drivers/ostm: Add renesas-ostm timer driver clocksource/drivers/ostm: Document renesas-ostm timer DT bindings clocksource/drivers/tcb_clksrc: Use 32 bit tcb as sched_clock clocksource/drivers/gemini: Add driver for the Cortina Gemini clocksource: add DT bindings for Cortina Gemini clockevents: Add a clkevt-of mechanism like clksrc-of tick/broadcast: Reduce lock cacheline contention timers: Omit POSIX timer stuff from task_struct when disabled x86/timer: Make delay() work during early bootup delay: Add explanation of udelay() inaccuracy ...
| * | timers: Omit POSIX timer stuff from task_struct when disabledNicolas Pitre2017-01-271-2/+2
| |/ | | | | | | | | | | | | | | | | | | When CONFIG_POSIX_TIMERS is disabled, it is preferable to remove related structures from struct task_struct and struct signal_struct as they won't contain anything useful and shouldn't be relied upon by mistake. Code still referencing those structures is also disabled here. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: John Stultz <john.stultz@linaro.org>
* / proc: add a schedule point in proc_pid_readdir()Eric Dumazet2017-01-251-0/+2
|/ | | | | | | | | | | We have seen proc_pid_readdir() invocations holding cpu for more than 50 ms. Add a cond_resched() to be gentle with other tasks. [akpm@linux-foundation.org: coding style fix] Link: http://lkml.kernel.org/r/1484238380.15816.42.camel@edumazet-glaptop3.roam.corp.google.com Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Replace <asm/uaccess.h> with <linux/uaccess.h> globallyLinus Torvalds2016-12-241-1/+1
| | | | | | | | | | | | | This was entirely automated, using the script by Al: PATT='^[[:blank:]]*#[[:blank:]]*include[[:blank:]]*<asm/uaccess.h>' sed -i -e "s!$PATT!#include <linux/uaccess.h>!" \ $(git grep -l "$PATT"|grep -v ^include/linux/uaccess.h) to do the replacement at the end of the merge window. Requested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds2016-12-141-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull audit updates from Paul Moore: "After the small number of patches for v4.9, we've got a much bigger pile for v4.10. The bulk of these patches involve a rework of the audit backlog queue to enable us to move the netlink multicasting out of the task/thread that generates the audit record and into the kernel thread that emits the record (just like we do for the audit unicast to auditd). While we were playing with the backlog queue(s) we fixed a number of other little problems with the code, and from all the testing so far things look to be in much better shape now. Doing this also allowed us to re-enable disabling IRQs for some netns operations ("netns: avoid disabling irq for netns id"). The remaining patches fix some small problems that are well documented in the commit descriptions, as well as adding session ID filtering support" * 'stable-4.10' of git://git.infradead.org/users/pcmoore/audit: audit: use proper refcount locking on audit_sock netns: avoid disabling irq for netns id audit: don't ever sleep on a command record/message audit: handle a clean auditd shutdown with grace audit: wake up kauditd_thread after auditd registers audit: rework audit_log_start() audit: rework the audit queue handling audit: rename the queues and kauditd related functions audit: queue netlink multicast sends just like we do for unicast sends audit: fixup audit_init() audit: move kaudit thread start from auditd registration to kaudit init (#2) audit: add support for session ID user filter audit: fix formatting of AUDIT_CONFIG_CHANGE events audit: skip sessionid sentinel value when auto-incrementing audit: tame initialization warning len_abuf in audit_log_execve_info audit: less stack usage for /proc/*/loginuid
| * audit: less stack usage for /proc/*/loginuidAlexey Dobriyan2016-11-031-1/+1
| | | | | | | | | | | | | | | | %u requires 10 characters at most not 20. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* | Merge branch 'next' of ↵Linus Torvalds2016-12-141-14/+9Star
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "Generally pretty quiet for this release. Highlights: Yama: - allow ptrace access for original parent after re-parenting TPM: - add documentation - many bugfixes & cleanups - define a generic open() method for ascii & bios measurements Integrity: - Harden against malformed xattrs SELinux: - bugfixes & cleanups Smack: - Remove unnecessary smack_known_invalid label - Do not apply star label in smack_setprocattr hook - parse mnt opts after privileges check (fixes unpriv DoS vuln)" * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (56 commits) Yama: allow access for the current ptrace parent tpm: adjust return value of tpm_read_log tpm: vtpm_proxy: conditionally call tpm_chip_unregister tpm: Fix handling of missing event log tpm: Check the bios_dir entry for NULL before accessing it tpm: return -ENODEV if np is not set tpm: cleanup of printk error messages tpm: replace of_find_node_by_name() with dev of_node property tpm: redefine read_log() to handle ACPI/OF at runtime tpm: fix the missing .owner in tpm_bios_measurements_ops tpm: have event log use the tpm_chip tpm: drop tpm1_chip_register(/unregister) tpm: replace dynamically allocated bios_dir with a static array tpm: replace symbolic permission with octal for securityfs files char: tpm: fix kerneldoc tpm2_unseal_trusted name typo tpm_tis: Allow tpm_tis to be bound using DT tpm, tpm_vtpm_proxy: add kdoc comments for VTPM_PROXY_IOC_NEW_DEV tpm: Only call pm_runtime_get_sync if device has a parent tpm: define a generic open() method for ascii & bios measurements Documentation: tpm: add the Physical TPM device tree binding documentation ...
| * \ Merge branch 'stable-4.10' of git://git.infradead.org/users/pcmoore/selinux ↵James Morris2016-11-241-14/+9Star
| |\ \ | | | | | | | | | | | | into next
| | * | proc: Pass file mode to proc_pid_make_inodeAndreas Gruenbacher2016-11-141-14/+9Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pass the file mode of the proc inode to be created to proc_pid_make_inode. In proc_pid_make_inode, initialize inode->i_mode before calling security_task_to_inode. This allows selinux to set isec->sclass right away without introducing "half-initialized" inode security structs. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* | | | fs/proc: calculate /proc/* and /proc/*/task/* nlink at init timeAlexey Dobriyan2016-12-131-6/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Runtime nlink calculation works but meh. I don't know how to do it at compile time, but I know how to do it at init time. Shift "2+" part into init time as a bonus. Link: http://lkml.kernel.org/r/20161122195549.GB29812@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | fs/proc/base.c: save decrement during lookup/readdir in /proc/$PIDAlexey Dobriyan2016-12-131-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Comparison for "<" works equally well as comparison for "<=" but one SUB/LEA is saved (no, it is not optimised away, at least here). Link: http://lkml.kernel.org/r/20161122195143.GA29812@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | proc: make struct struct map_files_info::len unsigned intAlexey Dobriyan2016-12-131-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux doesn't support 4GB+ filenames in /proc, so unsigned long is too much. MOV r64, r/m64 is larger than MOV r32, r/m32. Link: http://lkml.kernel.org/r/20161029161123.GG1246@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | proc: make struct pid_entry::len unsignedAlexey Dobriyan2016-12-131-1/+1
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | "unsigned int" is better on x86_64 because it most of the time it autoexpands to 64-bit value while "int" requires MOVSX instruction. Link: http://lkml.kernel.org/r/20161029160810.GF1246@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | proc: fix NULL dereference when reading /proc/<pid>/auxvLeon Yu2016-10-281-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reading auxv of any kernel thread results in NULL pointer dereferencing in auxv_read() where mm can be NULL. Fix that by checking for NULL mm and bailing out early. This is also the original behavior changed by recent commit c5317167854e ("proc: switch auxv to use of __mem_open()"). # cat /proc/2/auxv Unable to handle kernel NULL pointer dereference at virtual address 000000a8 Internal error: Oops: 17 [#1] PREEMPT SMP ARM CPU: 3 PID: 113 Comm: cat Not tainted 4.9.0-rc1-ARCH+ #1 Hardware name: BCM2709 task: ea3b0b00 task.stack: e99b2000 PC is at auxv_read+0x24/0x4c LR is at do_readv_writev+0x2fc/0x37c Process cat (pid: 113, stack limit = 0xe99b2210) Call chain: auxv_read do_readv_writev vfs_readv default_file_splice_read splice_direct_to_actor do_splice_direct do_sendfile SyS_sendfile64 ret_fast_syscall Fixes: c5317167854e ("proc: switch auxv to use of __mem_open()") Link: http://lkml.kernel.org/r/1476966200-14457-1-git-send-email-chianglungyu@gmail.com Signed-off-by: Leon Yu <chianglungyu@gmail.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Janis Danisevskis <jdanis@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | proc: don't use FOLL_FORCE for reading cmdline and environmentLinus Torvalds2016-10-251-10/+8Star
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that Lorenzo cleaned things up and made the FOLL_FORCE users explicit, it becomes obvious how some of them don't really need FOLL_FORCE at all. So remove FOLL_FORCE from the proc code that reads the command line and arguments from user space. The mem_rw() function actually does want FOLL_FORCE, because gdd (and possibly many other debuggers) use it as a much more convenient version of PTRACE_PEEKDATA, but we should consider making the FOLL_FORCE part conditional on actually being a ptracer. This does not actually do that, just moves adds a comment to that effect and moves the gup_flags settings next to each other. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: replace access_remote_vm() write parameter with gup_flagsLorenzo Stoakes2016-10-191-6/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | This removes the 'write' argument from access_remote_vm() and replaces it with 'gup_flags' as use of this function previously silently implied FOLL_FORCE, whereas after this patch callers explicitly pass this flag. We make this explicit as use of FOLL_FORCE can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'for-linus' of ↵Linus Torvalds2016-10-111-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
| * | fs: Replace CURRENT_TIME with current_time() for inode timestampsDeepa Dinamani2016-09-281-1/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CURRENT_TIME macro is not appropriate for filesystems as it doesn't use the right granularity for filesystem timestamps. Use current_time() instead. CURRENT_TIME is also not y2038 safe. This is also in preparation for the patch that transitions vfs timestamps to use 64 bit time and hence make them y2038 safe. As part of the effort current_time() will be extended to do range checks. Hence, it is necessary for all file system timestamps to use current_time(). Also, current_time() will be transitioned along with vfs to be y2038 safe. Note that whenever a single call to current_time() is used to change timestamps in different inodes, it is because they share the same time granularity. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Felipe Balbi <balbi@kernel.org> Acked-by: Steven Whitehouse <swhiteho@redhat.com> Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Acked-by: David Sterba <dsterba@suse.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | Merge branch 'work.misc' of ↵Linus Torvalds2016-10-101-20/+27
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted misc bits and pieces. There are several single-topic branches left after this (rename2 series from Miklos, current_time series from Deepa Dinamani, xattr series from Andreas, uaccess stuff from from me) and I'd prefer to send those separately" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits) proc: switch auxv to use of __mem_open() hpfs: support FIEMAP cifs: get rid of unused arguments of CIFSSMBWrite() posix_acl: uapi header split posix_acl: xattr representation cleanups fs/aio.c: eliminate redundant loads in put_aio_ring_file fs/internal.h: add const to ns_dentry_operations declaration compat: remove compat_printk() fs/buffer.c: make __getblk_slow() static proc: unsigned file descriptors fs/file: more unsigned file descriptors fs: compat: remove redundant check of nr_segs cachefiles: Fix attempt to read i_blocks after deleting file [ver #2] cifs: don't use memcpy() to copy struct iov_iter get rid of separate multipage fault-in primitives fs: Avoid premature clearing of capabilities fs: Give dentry to inode_change_ok() instead of inode fuse: Propagate dentry down to inode_change_ok() ceph: Propagate dentry down to inode_change_ok() xfs: Propagate dentry down to inode_change_ok() ...
| * \ Merge remote-tracking branch 'jk/vfs' into work.miscAl Viro2016-10-081-1/+1
| |\ \
| | * | fs: Give dentry to inode_change_ok() instead of inodeJan Kara2016-09-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
| * | | proc: switch auxv to use of __mem_open()Al Viro2016-10-061-19/+26
| | |/ | |/| | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | proc: fix timerslack_ns CAP_SYS_NICE check when adjusting selfJohn Stultz2016-10-081-15/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In changing from checking ptrace_may_access(p, PTRACE_MODE_ATTACH_FSCREDS) to capable(CAP_SYS_NICE), I missed that ptrace_my_access succeeds when p == current, but the CAP_SYS_NICE doesn't. Thus while the previous commit was intended to loosen the needed privileges to modify a processes timerslack, it needlessly restricted a task modifying its own timerslack via the proc/<tid>/timerslack_ns (which is permitted also via the PR_SET_TIMERSLACK method). This patch corrects this by checking if p == current before checking the CAP_SYS_NICE value. This patch applies on top of my two previous patches currently in -mm Link: http://lkml.kernel.org/r/1471906870-28624-1-git-send-email-john.stultz@linaro.org Signed-off-by: John Stultz <john.stultz@linaro.org> Acked-by: Kees Cook <keescook@chromium.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Oren Laadan <orenl@cellrox.com> Cc: Ruchi Kandoi <kandoiruchi@google.com> Cc: Rom Lemarchand <romlem@android.com> Cc: Todd Kjos <tkjos@google.com> Cc: Colin Cross <ccross@android.com> Cc: Nick Kralevich <nnk@google.com> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Elliott Hughes <enh@google.com> Cc: Android Kernel Team <kernel-team@android.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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