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* mm, proc: report PR_SET_THP_DISABLE in procMichal Hocko2018-12-281-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | David Rientjes has reported that commit 1860033237d4 ("mm: make PR_SET_THP_DISABLE immediately active") has changed the way how we report THPable VMAs to the userspace. Their monitoring tool is triggering false alarms on PR_SET_THP_DISABLE tasks because it considers an insufficient THP usage as a memory fragmentation resp. memory pressure issue. Before the said commit each newly created VMA inherited VM_NOHUGEPAGE flag and that got exposed to the userspace via /proc/<pid>/smaps file. This implementation had its downsides as explained in the commit message but it is true that the userspace doesn't have any means to query for the process wide THP enabled/disabled status. PR_SET_THP_DISABLE is a process wide flag so it makes a lot of sense to export in the process wide context rather than per-vma. Introduce a new field to /proc/<pid>/status which export this status. If PR_SET_THP_DISABLE is used then it reports false same as when the THP is not compiled in. It doesn't consider the global THP status because we already export that information via sysfs Link: http://lkml.kernel.org/r/20181211143641.3503-4-mhocko@kernel.org Fixes: 1860033237d4 ("mm: make PR_SET_THP_DISABLE immediately active") Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: David Rientjes <rientjes@google.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Paul Oppenheimer <bepvte@gmail.com> Cc: William Kucharski <william.kucharski@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm, thp, proc: report THP eligibility for each vmaMichal Hocko2018-12-281-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Userspace falls short when trying to find out whether a specific memory range is eligible for THP. There are usecases that would like to know that http://lkml.kernel.org/r/alpine.DEB.2.21.1809251248450.50347@chino.kir.corp.google.com : This is used to identify heap mappings that should be able to fault thp : but do not, and they normally point to a low-on-memory or fragmentation : issue. The only way to deduce this now is to query for hg resp. nh flags and confronting the state with the global setting. Except that there is also PR_SET_THP_DISABLE that might change the picture. So the final logic is not trivial. Moreover the eligibility of the vma depends on the type of VMA as well. In the past we have supported only anononymous memory VMAs but things have changed and shmem based vmas are supported as well these days and the query logic gets even more complicated because the eligibility depends on the mount option and another global configuration knob. Simplify the current state and report the THP eligibility in /proc/<pid>/smaps for each existing vma. Reuse transparent_hugepage_enabled for this purpose. The original implementation of this function assumes that the caller knows that the vma itself is supported for THP so make the core checks into __transparent_hugepage_enabled and use it for existing callers. __show_smap just use the new transparent_hugepage_enabled which also checks the vma support status (please note that this one has to be out of line due to include dependency issues). [mhocko@kernel.org: fix oops with NULL ->f_mapping] Link: http://lkml.kernel.org/r/20181224185106.GC16738@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20181211143641.3503-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Paul Oppenheimer <bepvte@gmail.com> Cc: William Kucharski <william.kucharski@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/mmu_notifier: use structure for invalidate_range_start/end calls v2Jérôme Glisse2018-12-281-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To avoid having to change many call sites everytime we want to add a parameter use a structure to group all parameters for the mmu_notifier invalidate_range_start/end cakks. No functional changes with this patch. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/20181205053628.3210-3-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <zwisler@kernel.org> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krcmar <rkrcmar@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Felix Kuehling <felix.kuehling@amd.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> From: Jérôme Glisse <jglisse@redhat.com> Subject: mm/mmu_notifier: use structure for invalidate_range_start/end calls v3 fix build warning in migrate.c when CONFIG_MMU_NOTIFIER=n Link: http://lkml.kernel.org/r/20181213171330.8489-3-jglisse@redhat.com Signed-off-by: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* /proc/kpagecount: return 0 for special pages that are never mappedAnthony Yznaga2018-12-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Certain pages that are never mapped to userspace have a type indicated in the page_type field of their struct pages (e.g. PG_buddy). page_type overlaps with _mapcount so set the count to 0 and avoid calling page_mapcount() for these pages. [anthony.yznaga@oracle.com: incorporate feedback from Matthew Wilcox] Link: http://lkml.kernel.org/r/1544481313-27318-1-git-send-email-anthony.yznaga@oracle.com Link: http://lkml.kernel.org/r/1543963526-27917-1-git-send-email-anthony.yznaga@oracle.com Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Miles Chen <miles.chen@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: convert totalram_pages and totalhigh_pages variables to atomicArun KS2018-12-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | totalram_pages and totalhigh_pages are made static inline function. Main motivation was that managed_page_count_lock handling was complicating things. It was discussed in length here, https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes better to remove the lock and convert variables to atomic, with preventing poteintial store-to-read tearing as a bonus. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org Signed-off-by: Arun KS <arunks@codeaurora.org> Suggested-by: Michal Hocko <mhocko@suse.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* proc/sysctl: don't return ENOMEM on lookup when a table is unregisteringIvan Delalande2018-12-141-7/+6
| | | | | | | | | | | | | | | | | | proc_sys_lookup can fail with ENOMEM instead of ENOENT when the corresponding sysctl table is being unregistered. In our case we see this upon opening /proc/sys/net/*/conf files while network interfaces are being deleted, which confuses our configuration daemon. The problem was successfully reproduced and this fix tested on v4.9.122 and v4.20-rc6. v2: return ERR_PTRs in all cases when proc_sys_make_inode fails instead of mixing them with NULL. Thanks Al Viro for the feedback. Fixes: ace0c791e6c3 ("proc/sysctl: Don't grab i_lock under sysctl_lock.") Cc: stable@vger.kernel.org Signed-off-by: Ivan Delalande <colona@arista.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge tag 'stackleak-v4.20-rc1' of ↵Linus Torvalds2018-11-011-0/+18
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull stackleak gcc plugin from Kees Cook: "Please pull this new GCC plugin, stackleak, for v4.20-rc1. This plugin was ported from grsecurity by Alexander Popov. It provides efficient stack content poisoning at syscall exit. This creates a defense against at least two classes of flaws: - Uninitialized stack usage. (We continue to work on improving the compiler to do this in other ways: e.g. unconditional zero init was proposed to GCC and Clang, and more plugin work has started too). - Stack content exposure. By greatly reducing the lifetime of valid stack contents, exposures via either direct read bugs or unknown cache side-channels become much more difficult to exploit. This complements the existing buddy and heap poisoning options, but provides the coverage for stacks. The x86 hooks are included in this series (which have been reviewed by Ingo, Dave Hansen, and Thomas Gleixner). The arm64 hooks have already been merged through the arm64 tree (written by Laura Abbott and reviewed by Mark Rutland and Will Deacon). With VLAs having been removed this release, there is no need for alloca() protection, so it has been removed from the plugin" * tag 'stackleak-v4.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: arm64: Drop unneeded stackleak_check_alloca() stackleak: Allow runtime disabling of kernel stack erasing doc: self-protection: Add information about STACKLEAK feature fs/proc: Show STACKLEAK metrics in the /proc file system lkdtm: Add a test for STACKLEAK gcc-plugins: Add STACKLEAK plugin for tracking the kernel stack x86/entry: Add STACKLEAK erasing the kernel stack at the end of syscalls
| * fs/proc: Show STACKLEAK metrics in the /proc file systemAlexander Popov2018-09-041-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | Introduce CONFIG_STACKLEAK_METRICS providing STACKLEAK information about tasks via the /proc file system. In particular, /proc/<pid>/stack_depth shows the maximum kernel stack consumption for the current and previous syscalls. Although this information is not precise, it can be useful for estimating the STACKLEAK performance impact for your workloads. Suggested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Alexander Popov <alex.popov@linux.com> Tested-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* | mm: remove include/linux/bootmem.hMike Rapoport2018-10-313-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move remaining definitions and declarations from include/linux/bootmem.h into include/linux/memblock.h and remove the redundant header. The includes were replaced with the semantic patch below and then semi-automated removal of duplicated '#include <linux/memblock.h> @@ @@ - #include <linux/bootmem.h> + #include <linux/memblock.h> [sfr@canb.auug.org.au: dma-direct: fix up for the removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181002185342.133d1680@canb.auug.org.au [sfr@canb.auug.org.au: powerpc: fix up for removal of linux/bootmem.h] Link: http://lkml.kernel.org/r/20181005161406.73ef8727@canb.auug.org.au [sfr@canb.auug.org.au: x86/kaslr, ACPI/NUMA: fix for linux/bootmem.h removal] Link: http://lkml.kernel.org/r/20181008190341.5e396491@canb.auug.org.au Link: http://lkml.kernel.org/r/1536927045-23536-30-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Chris Zankel <chris@zankel.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guan Xuetao <gxt@pku.edu.cn> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Jonas Bonn <jonas@southpole.se> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ley Foon Tan <lftan@altera.com> Cc: Mark Salter <msalter@redhat.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@sifive.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Richard Kuo <rkuo@codeaurora.org> Cc: Richard Weinberger <richard@nod.at> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Serge Semin <fancer.lancer@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | fs/proc/vmcore.c: Convert to use vmf_error()Souptick Joarder2018-10-311-1/+1
| | | | | | | | | | | | | | | | | | | | | | This code can be replaced with vmf_error() inline function. Link: http://lkml.kernel.org/r/20180918145945.GA11392@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Matthew Wilcox <willy@infradead.org> Cc: 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 'xarray' of git://git.infradead.org/users/willy/linux-daxLinus Torvalds2018-10-281-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull XArray conversion from Matthew Wilcox: "The XArray provides an improved interface to the radix tree data structure, providing locking as part of the API, specifying GFP flags at allocation time, eliminating preloading, less re-walking the tree, more efficient iterations and not exposing RCU-protected pointers to its users. This patch set 1. Introduces the XArray implementation 2. Converts the pagecache to use it 3. Converts memremap to use it The page cache is the most complex and important user of the radix tree, so converting it was most important. Converting the memremap code removes the only other user of the multiorder code, which allows us to remove the radix tree code that supported it. I have 40+ followup patches to convert many other users of the radix tree over to the XArray, but I'd like to get this part in first. The other conversions haven't been in linux-next and aren't suitable for applying yet, but you can see them in the xarray-conv branch if you're interested" * 'xarray' of git://git.infradead.org/users/willy/linux-dax: (90 commits) radix tree: Remove multiorder support radix tree test: Convert multiorder tests to XArray radix tree tests: Convert item_delete_rcu to XArray radix tree tests: Convert item_kill_tree to XArray radix tree tests: Move item_insert_order radix tree test suite: Remove multiorder benchmarking radix tree test suite: Remove __item_insert memremap: Convert to XArray xarray: Add range store functionality xarray: Move multiorder_check to in-kernel tests xarray: Move multiorder_shrink to kernel tests xarray: Move multiorder account test in-kernel radix tree test suite: Convert iteration test to XArray radix tree test suite: Convert tag_tagged_items to XArray radix tree: Remove radix_tree_clear_tags radix tree: Remove radix_tree_maybe_preload_order radix tree: Remove split/join code radix tree: Remove radix_tree_update_node_t page cache: Finish XArray conversion dax: Convert page fault handlers to XArray ...
| * | xarray: Replace exceptional entriesMatthew Wilcox2018-09-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce xarray value entries and tagged pointers to replace radix tree exceptional entries. This is a slight change in encoding to allow the use of an extra bit (we can now store BITS_PER_LONG - 1 bits in a value entry). It is also a change in emphasis; exceptional entries are intimidating and different. As the comment explains, you can choose to store values or pointers in the xarray and they are both first-class citizens. Signed-off-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Josef Bacik <jbacik@fb.com>
* | | mm: zero-seek shrinkersJohannes Weiner2018-10-271-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The page cache and most shrinkable slab caches hold data that has been read from disk, but there are some caches that only cache CPU work, such as the dentry and inode caches of procfs and sysfs, as well as the subset of radix tree nodes that track non-resident page cache. Currently, all these are shrunk at the same rate: using DEFAULT_SEEKS for the shrinker's seeks setting tells the reclaim algorithm that for every two page cache pages scanned it should scan one slab object. This is a bogus setting. A virtual inode that required no IO to create is not twice as valuable as a page cache page; shadow cache entries with eviction distances beyond the size of memory aren't either. In most cases, the behavior in practice is still fine. Such virtual caches don't tend to grow and assert themselves aggressively, and usually get picked up before they cause problems. But there are scenarios where that's not true. Our database workloads suffer from two of those. For one, their file workingset is several times bigger than available memory, which has the kernel aggressively create shadow page cache entries for the non-resident parts of it. The workingset code does tell the VM that most of these are expendable, but the VM ends up balancing them 2:1 to cache pages as per the seeks setting. This is a huge waste of memory. These workloads also deal with tens of thousands of open files and use /proc for introspection, which ends up growing the proc_inode_cache to absurdly large sizes - again at the cost of valuable cache space, which isn't a reasonable trade-off, given that proc inodes can be re-created without involving the disk. This patch implements a "zero-seek" setting for shrinkers that results in a target ratio of 0:1 between their objects and IO-backed caches. This allows such virtual caches to grow when memory is available (they do cache/avoid CPU work after all), but effectively disables them as soon as IO-backed objects are under pressure. It then switches the shrinkers for procfs and sysfs metadata, as well as excess page cache shadow nodes, to the new zero-seek setting. Link: http://lkml.kernel.org/r/20181009184732.762-5-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Domas Mituzas <dmituzas@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Rik van Riel <riel@surriel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | sched: loadavg: consolidate LOAD_INT, LOAD_FRAC, CALC_LOADJohannes Weiner2018-10-271-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are several definitions of those functions/macros in places that mess with fixed-point load averages. Provide an official version. [akpm@linux-foundation.org: fix missed conversion in block/blk-iolatency.c] Link: http://lkml.kernel.org/r/20180828172258.3185-5-hannes@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Suren Baghdasaryan <surenb@google.com> Tested-by: Daniel Drake <drake@endlessm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Weiner <jweiner@fb.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Enderborg <peter.enderborg@sony.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm, proc: add KReclaimable to /proc/meminfoVlastimil Babka2018-10-271-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The vmstat NR_KERNEL_MISC_RECLAIMABLE counter is for kernel non-slab allocations that can be reclaimed via shrinker. In /proc/meminfo, we can show the sum of all reclaimable kernel allocations (including slab) as "KReclaimable". Add the same counter also to per-node meminfo under /sys With this counter, users will have more complete information about kernel memory usage. Non-slab reclaimable pages (currently just the ION allocator) will not be missing from /proc/meminfo, making users wonder where part of their memory went. More precisely, they already appear in MemAvailable, but without the new counter, it's not obvious why the value in MemAvailable doesn't fully correspond with the sum of other counters participating in it. Link: http://lkml.kernel.org/r/20180731090649.16028-6-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Roman Gushchin <guro@fb.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Michal Hocko <mhocko@kernel.org> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Vijayanand Jitta <vjitta@codeaurora.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: /proc/pid/smaps_rollup: fix NULL pointer deref in smaps_pte_range()Vlastimil Babka2018-10-271-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Leonardo reports an apparent regression in 4.19-rc7: BUG: unable to handle kernel NULL pointer dereference at 00000000000000f0 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 3 PID: 6032 Comm: python Not tainted 4.19.0-041900rc7-lowlatency #201810071631 Hardware name: LENOVO 80UG/Toronto 4A2, BIOS 0XCN45WW 08/09/2018 RIP: 0010:smaps_pte_range+0x32d/0x540 Code: 80 00 00 00 00 74 a9 48 89 de 41 f6 40 52 40 0f 85 04 02 00 00 49 2b 30 48 c1 ee 0c 49 03 b0 98 00 00 00 49 8b 80 a0 00 00 00 <48> 8b b8 f0 00 00 00 e8 b7 ef ec ff 48 85 c0 0f 84 71 ff ff ff a8 RSP: 0018:ffffb0cbc484fb88 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000560ddb9e9000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000560ddb9e9 RDI: 0000000000000001 RBP: ffffb0cbc484fbc0 R08: ffff94a5a227a578 R09: ffff94a5a227a578 R10: 0000000000000000 R11: 0000560ddbbe7000 R12: ffffe903098ba728 R13: ffffb0cbc484fc78 R14: ffffb0cbc484fcf8 R15: ffff94a5a2e9cf48 FS: 00007f6dfb683740(0000) GS:ffff94a5aaf80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000f0 CR3: 000000011c118001 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __walk_page_range+0x3c2/0x6f0 walk_page_vma+0x42/0x60 smap_gather_stats+0x79/0xe0 ? gather_pte_stats+0x320/0x320 ? gather_hugetlb_stats+0x70/0x70 show_smaps_rollup+0xcd/0x1c0 seq_read+0x157/0x400 __vfs_read+0x3a/0x180 ? security_file_permission+0x93/0xc0 ? security_file_permission+0x93/0xc0 vfs_read+0x8f/0x140 ksys_read+0x55/0xc0 __x64_sys_read+0x1a/0x20 do_syscall_64+0x5a/0x110 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Decoded code matched to local compilation+disassembly points to smaps_pte_entry(): } else if (unlikely(IS_ENABLED(CONFIG_SHMEM) && mss->check_shmem_swap && pte_none(*pte))) { page = find_get_entry(vma->vm_file->f_mapping, linear_page_index(vma, addr)); Here, vma->vm_file is NULL. mss->check_shmem_swap should be false in that case, however for smaps_rollup, smap_gather_stats() can set the flag true for one vma and leave it true for subsequent vma's where it should be false. To fix, reset the check_shmem_swap flag to false. There's also related bug which sets mss->swap to shmem_swapped, which in the context of smaps_rollup overwrites any value accumulated from previous vma's. Fix that as well. Note that the report suggests a regression between 4.17.19 and 4.19-rc7, which makes the 4.19 series ending with commit 258f669e7e88 ("mm: /proc/pid/smaps_rollup: convert to single value seq_file") suspicious. But the mss was reused for rollup since 493b0e9d945f ("mm: add /proc/pid/smaps_rollup") so let's play it safe with the stable backport. Link: http://lkml.kernel.org/r/555fbd1f-4ac9-0b58-dcd4-5dc4380ff7ca@suse.cz Link: https://bugzilla.kernel.org/show_bug.cgi?id=201377 Fixes: 493b0e9d945f ("mm: add /proc/pid/smaps_rollup") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Leonardo Soares Müller <leozinho29_eu@hotmail.com> Tested-by: Leonardo Soares Müller <leozinho29_eu@hotmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Daniel Colascione <dancol@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds2018-10-231-6/+28
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 mm updates from Ingo Molnar: "Lots of changes in this cycle: - Lots of CPA (change page attribute) optimizations and related cleanups (Thomas Gleixner, Peter Zijstra) - Make lazy TLB mode even lazier (Rik van Riel) - Fault handler cleanups and improvements (Dave Hansen) - kdump, vmcore: Enable kdumping encrypted memory with AMD SME enabled (Lianbo Jiang) - Clean up VM layout documentation (Baoquan He, Ingo Molnar) - ... plus misc other fixes and enhancements" * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits) x86/stackprotector: Remove the call to boot_init_stack_canary() from cpu_startup_entry() x86/mm: Kill stray kernel fault handling comment x86/mm: Do not warn about PCI BIOS W+X mappings resource: Clean it up a bit resource: Fix find_next_iomem_res() iteration issue resource: Include resource end in walk_*() interfaces x86/kexec: Correct KEXEC_BACKUP_SRC_END off-by-one error x86/mm: Remove spurious fault pkey check x86/mm/vsyscall: Consider vsyscall page part of user address space x86/mm: Add vsyscall address helper x86/mm: Fix exception table comments x86/mm: Add clarifying comments for user addr space x86/mm: Break out user address space handling x86/mm: Break out kernel address space handling x86/mm: Clarify hardware vs. software "error_code" x86/mm/tlb: Make lazy TLB mode lazier x86/mm/tlb: Add freed_tables element to flush_tlb_info x86/mm/tlb: Add freed_tables argument to flush_tlb_mm_range smp,cpumask: introduce on_each_cpu_cond_mask smp: use __cpumask_set_cpu in on_each_cpu_cond ...
| * | | proc/vmcore: Fix i386 build error of missing copy_oldmem_page_encrypted()Borislav Petkov2018-10-091-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lianbo reported a build error with a particular 32-bit config, see Link below for details. Provide a weak copy_oldmem_page_encrypted() function which architectures can override, in the same manner other functionality in that file is supplied. Reported-by: Lianbo Jiang <lijiang@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> CC: x86@kernel.org Link: http://lkml.kernel.org/r/710b9d95-2f70-eadf-c4a1-c3dc80ee4ebb@redhat.com
| * | | kdump, proc/vmcore: Enable kdumping encrypted memory with SME enabledLianbo Jiang2018-10-061-6/+18
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the kdump kernel, the memory of the first kernel needs to be dumped into the vmcore file. If SME is enabled in the first kernel, the old memory has to be remapped with the memory encryption mask in order to access it properly. Split copy_oldmem_page() functionality to handle encrypted memory properly. [ bp: Heavily massage everything. ] Signed-off-by: Lianbo Jiang <lijiang@redhat.com> Signed-off-by: Borislav Petkov <bp@suse.de> Cc: kexec@lists.infradead.org Cc: tglx@linutronix.de Cc: mingo@redhat.com Cc: hpa@zytor.com Cc: akpm@linux-foundation.org Cc: dan.j.williams@intel.com Cc: bhelgaas@google.com Cc: baiyaowei@cmss.chinamobile.com Cc: tiwai@suse.de Cc: brijesh.singh@amd.com Cc: dyoung@redhat.com Cc: bhe@redhat.com Cc: jroedel@suse.de Link: https://lkml.kernel.org/r/be7b47f9-6be6-e0d1-2c2a-9125bc74b818@redhat.com
* / / proc: restrict kernel stack dumps to rootJann Horn2018-10-061-0/+14
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, you can use /proc/self/task/*/stack to cause a stack walk on a task you control while it is running on another CPU. That means that the stack can change under the stack walker. The stack walker does have guards against going completely off the rails and into random kernel memory, but it can interpret random data from your kernel stack as instruction pointers and stack pointers. This can cause exposure of kernel stack contents to userspace. Restrict the ability to inspect kernel stacks of arbitrary tasks to root in order to prevent a local attacker from exploiting racy stack unwinding to leak kernel task stack contents. See the added comment for a longer rationale. There don't seem to be any users of this userspace API that can't gracefully bail out if reading from the file fails. Therefore, I believe that this change is unlikely to break things. In the case that this patch does end up needing a revert, the next-best solution might be to fake a single-entry stack based on wchan. Link: http://lkml.kernel.org/r/20180927153316.200286-1-jannh@google.com Fixes: 2ec220e27f50 ("proc: add /proc/*/stack") Signed-off-by: Jann Horn <jannh@google.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Ken Chen <kenchen@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H . Peter Anvin" <hpa@zytor.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* / fs/proc/kcore.c: fix invalid memory access in multi-page read optimizationDominique Martinet2018-09-201-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | The 'm' kcore_list item could point to kclist_head, and it is incorrect to look at m->addr / m->size in this case. There is no choice but to run through the list of entries for every address if we did not find any entry in the previous iteration Reset 'm' to NULL in that case at Omar Sandoval's suggestion. [akpm@linux-foundation.org: add comment] Link: http://lkml.kernel.org/r/1536100702-28706-1-git-send-email-asmadeus@codewreck.org Fixes: bf991c2231117 ("proc/kcore: optimize multiple page reads") Signed-off-by: Dominique Martinet <asmadeus@codewreck.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Omar Sandoval <osandov@osandov.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds2018-08-261-2/+5
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf updates from Thomas Gleixner: "Kernel: - Improve kallsyms coverage - Add x86 entry trampolines to kcore - Fix ARM SPE handling - Correct PPC event post processing Tools: - Make the build system more robust - Small fixes and enhancements all over the place - Update kernel ABI header copies - Preparatory work for converting libtraceevnt to a shared library - License cleanups" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (100 commits) tools arch: Update arch/x86/lib/memcpy_64.S copy used in 'perf bench mem memcpy' tools arch x86: Update tools's copy of cpufeatures.h perf python: Fix pyrf_evlist__read_on_cpu() interface perf mmap: Store real cpu number in 'struct perf_mmap' perf tools: Remove ext from struct kmod_path perf tools: Add gzip_is_compressed function perf tools: Add lzma_is_compressed function perf tools: Add is_compressed callback to compressions array perf tools: Move the temp file processing into decompress_kmodule perf tools: Use compression id in decompress_kmodule() perf tools: Store compression id into struct dso perf tools: Add compression id into 'struct kmod_path' perf tools: Make is_supported_compression() static perf tools: Make decompress_to_file() function static perf tools: Get rid of dso__needs_decompress() call in __open_dso() perf tools: Get rid of dso__needs_decompress() call in symbol__disassemble() perf tools: Get rid of dso__needs_decompress() call in read_object_code() tools lib traceevent: Change to SPDX License format perf llvm: Allow passing options to llc in addition to clang perf parser: Improve error message for PMU address filters ...
| * x86: Add entry trampolines to kcoreAdrian Hunter2018-08-151-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Without program headers for PTI entry trampoline pages, the trampoline virtual addresses do not map to anything. Example before: sudo gdb --quiet vmlinux /proc/kcore Reading symbols from vmlinux...done. [New process 1] Core was generated by `BOOT_IMAGE=/boot/vmlinuz-4.16.0 root=UUID=a6096b83-b763-4101-807e-f33daff63233'. #0 0x0000000000000000 in irq_stack_union () (gdb) x /21ib 0xfffffe0000006000 0xfffffe0000006000: Cannot access memory at address 0xfffffe0000006000 (gdb) quit After: sudo gdb --quiet vmlinux /proc/kcore [sudo] password for ahunter: Reading symbols from vmlinux...done. [New process 1] Core was generated by `BOOT_IMAGE=/boot/vmlinuz-4.16.0-fix-4-00005-gd6e65a8b4072 root=UUID=a6096b83-b7'. #0 0x0000000000000000 in irq_stack_union () (gdb) x /21ib 0xfffffe0000006000 0xfffffe0000006000: swapgs 0xfffffe0000006003: mov %rsp,-0x3e12(%rip) # 0xfffffe00000021f8 0xfffffe000000600a: xchg %ax,%ax 0xfffffe000000600c: mov %cr3,%rsp 0xfffffe000000600f: bts $0x3f,%rsp 0xfffffe0000006014: and $0xffffffffffffe7ff,%rsp 0xfffffe000000601b: mov %rsp,%cr3 0xfffffe000000601e: mov -0x3019(%rip),%rsp # 0xfffffe000000300c 0xfffffe0000006025: pushq $0x2b 0xfffffe0000006027: pushq -0x3e35(%rip) # 0xfffffe00000021f8 0xfffffe000000602d: push %r11 0xfffffe000000602f: pushq $0x33 0xfffffe0000006031: push %rcx 0xfffffe0000006032: push %rdi 0xfffffe0000006033: mov $0xffffffff91a00010,%rdi 0xfffffe000000603a: callq 0xfffffe0000006046 0xfffffe000000603f: pause 0xfffffe0000006041: lfence 0xfffffe0000006044: jmp 0xfffffe000000603f 0xfffffe0000006046: mov %rdi,(%rsp) 0xfffffe000000604a: retq (gdb) quit In addition, entry trampolines all map to the same page. Represent that by giving the corresponding program headers in kcore the same offset. This has the benefit that, when perf tools uses /proc/kcore as a source for kernel object code, samples from different CPU trampolines are aggregated together. Note, such aggregation is normal for profiling i.e. people want to profile the object code, not every different virtual address the object code might be mapped to (across different processes for example). Notes by PeterZ: This also adds the KCORE_REMAP functionality. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Acked-by: Andi Kleen <ak@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: x86@kernel.org Link: http://lkml.kernel.org/r/1528289651-4113-4-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | fs/proc/vmcore.c: hide vmcoredd_mmap_dumps() for nommu buildsArnd Bergmann2018-08-241-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Without CONFIG_MMU, we get a build warning: fs/proc/vmcore.c:228:12: error: 'vmcoredd_mmap_dumps' defined but not used [-Werror=unused-function] static int vmcoredd_mmap_dumps(struct vm_area_struct *vma, unsigned long dst, The function is only referenced from an #ifdef'ed caller, so this uses the same #ifdef around it. Link: http://lkml.kernel.org/r/20180525213526.2117790-1-arnd@arndb.de Fixes: 7efe48df8a3d ("vmcore: append device dumps to vmcore as elf notes") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Ganesh Goudar <ganeshgr@chelsio.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc/kcore: add vmcoreinfo note to /proc/kcoreOmar Sandoval2018-08-222-2/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The vmcoreinfo information is useful for runtime debugging tools, not just for crash dumps. A lot of this information can be determined by other means, but this is much more convenient, and it only adds a page at most to the file. Link: http://lkml.kernel.org/r/fddbcd08eed76344863303878b12de1c1e2a04b6.1531953780.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc/kcore: optimize multiple page readsOmar Sandoval2018-08-221-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current code does a full search of the segment list every time for every page. This is wasteful, since it's almost certain that the next page will be in the same segment. Instead, check if the previous segment covers the current page before doing the list search. Link: http://lkml.kernel.org/r/fd346c11090cf93d867e01b8d73a6567c5ac6361.1531953780.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc/kcore: clean up ELF header generationOmar Sandoval2018-08-221-209/+141
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the ELF file header, program headers, and note segment are allocated all at once, in some icky code dating back to 2.3. Programs tend to read the file header, then the program headers, then the note segment, all separately, so this is a waste of effort. It's cleaner and more efficient to handle the three separately. Link: http://lkml.kernel.org/r/19c92cbad0e11f6103ff3274b2e7a7e51a1eb74b.1531953780.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc/kcore: hold lock during readOmar Sandoval2018-08-221-30/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that we're using an rwsem, we can hold it during the entirety of read_kcore() and have a common return path. This is preparation for the next change. [akpm@linux-foundation.org: fix locking bug reported by Tetsuo Handa] Link: http://lkml.kernel.org/r/d7cfbc1e8a76616f3b699eaff9df0a2730380534.1531953780.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc/kcore: fix memory hotplug vs multiple opens raceOmar Sandoval2018-08-221-49/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a theoretical race condition that will cause /proc/kcore to miss a memory hotplug event: CPU0 CPU1 // hotplug event 1 kcore_need_update = 1 open_kcore() open_kcore() kcore_update_ram() kcore_update_ram() // Walk RAM // Walk RAM __kcore_update_ram() __kcore_update_ram() kcore_need_update = 0 // hotplug event 2 kcore_need_update = 1 kcore_need_update = 0 Note that CPU1 set up the RAM kcore entries with the state after hotplug event 1 but cleared the flag for hotplug event 2. The RAM entries will therefore be stale until there is another hotplug event. This is an extremely unlikely sequence of events, but the fix makes the synchronization saner, anyways: we serialize the entire update sequence, which means that whoever clears the flag will always succeed in replacing the kcore list. Link: http://lkml.kernel.org/r/6106c509998779730c12400c1b996425df7d7089.1531953780.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc/kcore: replace kclist_lock rwlock with rwsemOmar Sandoval2018-08-221-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now we only need kclist_lock from user context and at fs init time, and the following changes need to sleep while holding the kclist_lock. Link: http://lkml.kernel.org/r/521ba449ebe921d905177410fee9222d07882f0d.1531953780.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc/kcore: don't grab lock for memory hotplug notifierOmar Sandoval2018-08-221-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The memory hotplug notifier kcore_callback() only needs kclist_lock to prevent races with __kcore_update_ram(), but we can easily eliminate that race by using an atomic xchg() in __kcore_update_ram(). This is preparation for converting kclist_lock to an rwsem. Link: http://lkml.kernel.org/r/0a4bc89f4dbde8b5b2ea309f7b4fb6a85fe29df2.1531953780.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc/kcore: don't grab lock for kclist_add()Omar Sandoval2018-08-221-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "/proc/kcore improvements", v4. This series makes a few improvements to /proc/kcore. It fixes a couple of small issues in v3 but is otherwise the same. Patches 1, 2, and 3 are prep patches. Patch 4 is a fix/cleanup. Patch 5 is another prep patch. Patches 6 and 7 are optimizations to ->read(). Patch 8 makes it possible to enable CRASH_CORE on any architecture, which is needed for patch 9. Patch 9 adds vmcoreinfo to /proc/kcore. This patch (of 9): kclist_add() is only called at init time, so there's no point in grabbing any locks. We're also going to replace the rwlock with a rwsem, which we don't want to try grabbing during early boot. While we're here, mark kclist_add() with __init so that we'll get a warning if it's called from non-init code. Link: http://lkml.kernel.org/r/98208db1faf167aa8b08eebfa968d95c70527739.1531953780.git.osandov@fb.com Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Tested-by: Bhupesh Sharma <bhsharma@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bhupesh Sharma <bhsharma@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | fs/proc/kcore.c: use __pa_symbol() for KCORE_TEXT list entriesJames Morse2018-08-221-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | elf_kcore_store_hdr() uses __pa() to find the physical address of KCORE_RAM or KCORE_TEXT entries exported as program headers. This trips CONFIG_DEBUG_VIRTUAL's checks, as the KCORE_TEXT entries are not in the linear map. Handle these two cases separately, using __pa_symbol() for the KCORE_TEXT entries. Link: http://lkml.kernel.org/r/20180711131944.15252-1-james.morse@arm.com Signed-off-by: James Morse <james.morse@arm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Omar Sandoval <osandov@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | fs/proc/vmcore.c: use new typedef vm_fault_tSouptick Joarder2018-08-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use new return type vm_fault_t for fault handler in struct vm_operations_struct. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. See 1c8f422059ae ("mm: change return type to vm_fault_t") for reference. Link: http://lkml.kernel.org/r/20180702153325.GA3875@jordon-HP-15-Notebook-PC Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ganesh Goudar <ganeshgr@chelsio.com> Cc: Rahul Lakkireddy <rahul.lakkireddy@chelsio.com> Cc: David S. Miller <davem@davemloft.net> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc: use "unsigned int" in /proc/stat hookAlexey Dobriyan2018-08-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | Number of CPUs is never high enough to force 64-bit arithmetic. Save couple of bytes on x86_64. Link: http://lkml.kernel.org/r/20180627200710.GC18434@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc: spread "const" a bitAlexey Dobriyan2018-08-221-2/+2
| | | | | | | | | | | | | | | | Link: http://lkml.kernel.org/r/20180627200614.GB18434@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc: use macro in /proc/latency hookAlexey Dobriyan2018-08-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | ->latency_record is defined as struct latency_record[LT_SAVECOUNT]; so use the same macro whie iterating. Link: http://lkml.kernel.org/r/20180627200534.GA18434@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc: save 2 atomic ops on write to "/proc/*/attr/*"Alexey Dobriyan2018-08-221-19/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Code checks if write is done by current to its own attributes. For that get/put pair is unnecessary as it can be done under RCU. Note: rcu_read_unlock() can be done even earlier since pointer to a task is not dereferenced. It depends if /proc code should look scary or not: rcu_read_lock(); task = pid_task(...); rcu_read_unlock(); if (!task) return -ESRCH; if (task != current) return -EACCESS: P.S.: rename "length" variable. Code like this length = -EINVAL; should not exist. Link: http://lkml.kernel.org/r/20180627200218.GF18113@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc: put task earlier in /proc/*/fail-nthAlexey Dobriyan2018-08-221-3/+1
| | | | | | | | | | | | | | | | Link: http://lkml.kernel.org/r/20180627195427.GE18113@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc: smaller readlock section in readdir("/proc")Alexey Dobriyan2018-08-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | Readdir context is thread local, so ->pos is thread local, move it out of readlock. Link: http://lkml.kernel.org/r/20180627195339.GD18113@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | fs/proc/uptime.c: use ktime_get_boottime_ts64Arnd Bergmann2018-08-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | get_monotonic_boottime() is deprecated and uses the old timespec type. Let's convert /proc/uptime to use ktime_get_boottime_ts64(). Link: http://lkml.kernel.org/r/20180620081746.282742-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Deepa Dinamani <deepa.kernel@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | proc: fixup PDE allocation bloatAlexey Dobriyan2018-08-222-12/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 24074a35c5c975 ("proc: Make inline name size calculation automatic") started to put PDE allocations into kmalloc-256 which is unnecessary as ~40 character names are very rare. Put allocation back into kmalloc-192 cache for 64-bit non-debug builds. Put BUILD_BUG_ON to know when PDE size has gotten out of control. [adobriyan@gmail.com: fix BUILD_BUG_ON breakage on powerpc64] Link: http://lkml.kernel.org/r/20180703191602.GA25521@avx2 Link: http://lkml.kernel.org/r/20180617215732.GA24688@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | /proc/meminfo: add percpu populated pages countDennis Zhou (Facebook)2018-08-221-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, percpu memory only exposes allocation and utilization information via debugfs. This more or less is only really useful for understanding the fragmentation and allocation information at a per-chunk level with a few global counters. This is also gated behind a config. BPF and cgroup, for example, have seen an increase in use causing increased use of percpu memory. Let's make it easier for someone to identify how much memory is being used. This patch adds the "Percpu" stat to meminfo to more easily look up how much percpu memory is in use. This number includes the cost for all allocated backing pages and not just insight at the per a unit, per chunk level. Metadata is excluded. I think excluding metadata is fair because the backing memory scales with the numbere of cpus and can quickly outweigh the metadata. It also makes this calculation light. Link: http://lkml.kernel.org/r/20180807184723.74919-1-dennisszhou@gmail.com Signed-off-by: Dennis Zhou <dennisszhou@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Roman Gushchin <guro@fb.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: /proc/pid/smaps_rollup: convert to single value seq_fileVlastimil Babka2018-08-222-60/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The /proc/pid/smaps_rollup file is currently implemented via the m_start/m_next/m_stop seq_file iterators shared with the other maps files, that iterate over vma's. However, the rollup file doesn't print anything for each vma, only accumulate the stats. There are some issues with the current code as reported in [1] - the accumulated stats can get skewed if seq_file start()/stop() op is called multiple times, if show() is called multiple times, and after seeks to non-zero position. Patch [1] fixed those within existing design, but I believe it is fundamentally wrong to expose the vma iterators to the seq_file mechanism when smaps_rollup shows logically a single set of values for the whole address space. This patch thus refactors the code to provide a single "value" at offset 0, with vma iteration to gather the stats done internally. This fixes the situations where results are skewed, and simplifies the code, especially in show_smap(), at the expense of somewhat less code reuse. [1] https://marc.info/?l=linux-mm&m=151927723128134&w=2 [vbabka@suse.c: use seq_file infrastructure] Link: http://lkml.kernel.org/r/bf4525b0-fd5b-4c4c-2cb3-adee3dd95a48@suse.cz Link: http://lkml.kernel.org/r/20180723111933.15443-5-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Daniel Colascione <dancol@google.com> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: /proc/pid/smaps: factor out common stats printingVlastimil Babka2018-08-221-22/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To prepare for handling /proc/pid/smaps_rollup differently from /proc/pid/smaps factor out from show_smap() printing the parts of output that are common for both variants, which is the bulk of the gathered memory stats. [vbabka@suse.cz: add const, per Alexey] Link: http://lkml.kernel.org/r/b45f319f-cd04-337b-37f8-77f99786aa8a@suse.cz Link: http://lkml.kernel.org/r/20180723111933.15443-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Daniel Colascione <dancol@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: /proc/pid/smaps: factor out mem stats gatheringVlastimil Babka2018-08-221-24/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | To prepare for handling /proc/pid/smaps_rollup differently from /proc/pid/smaps factor out vma mem stats gathering from show_smap() - it will be used by both. Link: http://lkml.kernel.org/r/20180723111933.15443-3-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Daniel Colascione <dancol@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: /proc/pid/*maps remove is_pid and related wrappersVlastimil Babka2018-08-224-144/+18
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "cleanups and refactor of /proc/pid/smaps*". The recent regression in /proc/pid/smaps made me look more into the code. Especially the issues with smaps_rollup reported in [1] as explained in Patch 4, which fixes them by refactoring the code. Patches 2 and 3 are preparations for that. Patch 1 is me realizing that there's a lot of boilerplate left from times where we tried (unsuccessfuly) to mark thread stacks in the output. Originally I had also plans to rework the translation from /proc/pid/*maps* file offsets to the internal structures. Now the offset means "vma number", which is not really stable (vma's can come and go between read() calls) and there's an extra caching of last vma's address. My idea was that offsets would be interpreted directly as addresses, which would also allow meaningful seeks (see the ugly seek_to_smaps_entry() in tools/testing/selftests/vm/mlock2.h). However loff_t is (signed) long long so that might be insufficient somewhere for the unsigned long addresses. So the result is fixed issues with skewed /proc/pid/smaps_rollup results, simpler smaps code, and a lot of unused code removed. [1] https://marc.info/?l=linux-mm&m=151927723128134&w=2 This patch (of 4): Commit b76437579d13 ("procfs: mark thread stack correctly in proc/<pid>/maps") introduced differences between /proc/PID/maps and /proc/PID/task/TID/maps to mark thread stacks properly, and this was also done for smaps and numa_maps. However it didn't work properly and was ultimately removed by commit b18cb64ead40 ("fs/proc: Stop trying to report thread stacks"). Now the is_pid parameter for the related show_*() functions is unused and we can remove it together with wrapper functions and ops structures that differ for PID and TID cases only in this parameter. Link: http://lkml.kernel.org/r/20180723111933.15443-2-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Daniel Colascione <dancol@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/proc/task_mmu.c: fix Locked field in /proc/pid/smaps*Vlastimil Babka2018-07-141-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Thomas reports: "While looking around in /proc on my v4.14.52 system I noticed that all processes got a lot of "Locked" memory in /proc/*/smaps. A lot more memory than a regular user can usually lock with mlock(). Commit 493b0e9d945f (in v4.14-rc1) seems to have changed the behavior of "Locked". Before that commit the code was like this. Notice the VM_LOCKED check. (vma->vm_flags & VM_LOCKED) ? (unsigned long)(mss.pss >> (10 + PSS_SHIFT)) : 0); After that commit Locked is now the same as Pss: (unsigned long)(mss->pss >> (10 + PSS_SHIFT))); This looks like a mistake." Indeed, the commit has added mss->pss_locked with the correct value that depends on VM_LOCKED, but forgot to actually use it. Fix it. Link: http://lkml.kernel.org/r/ebf6c7fb-fec3-6a26-544f-710ed193c154@suse.cz Fixes: 493b0e9d945f ("mm: add /proc/pid/smaps_rollup") Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reported-by: Thomas Lindroth <thomas.lindroth@gmail.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Daniel Colascione <dancol@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds2018-07-011-1/+10
|\ | | | | | | | | | | | | | | | | | | | | | | Pull vfs fix from Al Viro: "Followup to procfs-seq_file series this window" This fixes a memory leak by making sure that proc seq files release any private data on close. The 'proc_seq_open' has to be properly paired with 'proc_seq_release' that releases the extra private data. * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: proc: add proc_seq_release
| * proc: add proc_seq_releaseChunyu Hu2018-06-281-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kmemleak reported some memory leak on reading proc files. After adding some debug lines, find that proc_seq_fops is using seq_release as release handler, which won't handle the free of 'private' field of seq_file, while in fact the open handler proc_seq_open could create the private data with __seq_open_private when state_size is greater than zero. So after reading files created with proc_create_seq_private, such as /proc/timer_list and /proc/vmallocinfo, the private mem of a seq_file is not freed. Fix it by adding the paired proc_seq_release as the default release handler of proc_seq_ops instead of seq_release. Fixes: 44414d82cfe0 ("proc: introduce proc_create_seq_private") Reviewed-by: Christoph Hellwig <hch@lst.de> CC: Christoph Hellwig <hch@lst.de> Signed-off-by: Chunyu Hu <chuhu@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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